The University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a 2,000-acre campus in North Central Florida. Howard and Matthew Greene recognized Florida as a Public Ivy in 2001, a publicly funded university considered as providing a quality of education comparable to those of the Ivies. In 2014, U.S. News & World Report ranked Florida as the fourteenth best public university in the United States. It is a senior member of the State University System of Florida and traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906.The University of Florida is an elected member of the Association of American Universities , the association of preeminent North American research universities. The University is classified as a Research University with Very High Research by the Carnegie Foundation for the Advancement of Teaching. The university is accredited by the Southern Association of Colleges and Schools . Florida Governor Rick Scott and the state Legislature designated the University of Florida as one of two "preeminent" state universities in the spring of 2013. It is the third largest Florida university by student population, and is the eighth largest single-campus university in the United States with 49,913 students enrolled for the fall 2012 semester. The University of Florida is home to sixteen academic colleges and more than 150 research centers and institutes. It offers multiple graduate professional programs—including business administration, engineering, law, dentistry, medicine, and veterinary medicine—on one contiguous campus, and administers 123 master's degree programs and seventy-six doctoral degree programs in eighty-seven schools and departments.The University of Florida's intercollegiate sports teams, commonly known by their "Florida Gators" nickname, compete in National Collegiate Athletic Association Division I and the Southeastern Conference . In their 108-year history, the university's varsity sports teams have won thirty-three national team championships, twenty-eight of which are NCAA titles, and Gator athletes have won 267 individual national championships. Wikipedia.
Watts A.C.,University of Florida
Forest Ecology and Management | Year: 2013
Swamps, peatlands, and other wetland ecosystems can store vast amounts of carbon in organically-derived peat soils. Wildfires during severe droughts can produce smoldering combustion in these soils, releasing large quantities of carbon to the atmosphere and causing dramatic changes at the local scale due to plant mortality and hydrologic effects. I studied variation in moisture content and carbon loss from smoldering combustion in soils from pondcypress (Taxodium distichum var. imbricarium) swamps in Florida USA. In a lab study, soil moisture content near the surface (upper 10cm) did not predict vertical depth of soil combustion. Mass loss of organic carbon from soil profiles was, however, negatively related (P<0.01). I also studied spatial variation in soil moisture, as a predictor of potential soil combustion, at a range of distances from edges of cypress-swamp patches. A weak, but significant (P<0.01), positive relationship exists between distance from edges and upper-layer soil moisture, indicating that some inhibitive effect on smoldering may be present proceeding toward the centers of larger swamp patches. Conservative estimates of SOC content in cypress peats (approximately 41% by mass, compared to a figure of 50% sometimes used in such studies) indicate substantial potential for soil carbon loss (over 4kgm2) from wildfires in cypress swamps. This initial study on smoldering of cypress peats also makes recommendations for future efforts to study ground fires in these regionally important ecosystems. © 2012 Elsevier B.V.
Clark B.C.,Ohio University |
Manini T.M.,University of Florida
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2010
Purpose of review: The economic burden due to the sequela of sarcopenia (muscle wasting in the elderly) are staggering and rank similarly to the costs associated with osteoporotic fractures. In this article, we discuss the societal burden and determinants of the loss of physical function with advancing age, the physiologic mechanisms underlying dynapenia (muscle weakness in the elderly), and provide perspectives on related critical issues to be addressed. Recent findings: Recent epidemiological findings from longitudinal aging studies suggest that dynapenia is highly associated with both mortality and physical disability even when adjusting for sarcopenia indicating that sarcopenia may be secondary to the effects of dynapenia. These findings are consistent with the physiologic underpinnings of muscle strength, as recent evidence demonstrates that alterations in muscle quantity, contractile quality and neural activation all collectively contribute to dynapenia. Summary: Although muscle mass is essential for regulation of whole body metabolic balance, overall neuromuscular function seems to be a critical factor for maintaining muscle strength and physical independence in the elderly. The relative contribution of physiologic factors contributing to muscle weakness are not fully understood and further research is needed to better elucidate these mechanisms between muscle groups and across populations. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Weinstein D.A.,University of Florida
Human gene therapy | Year: 2010
Glycogen storage disease type Ia (GSDIa; von Gierke disease; MIM 232200) is caused by a deficiency in glucose-6-phosphatase-alpha. Patients with GSDIa are unable to maintain glucose homeostasis and suffer from severe hypoglycemia, hepatomegaly, hyperlipidemia, hyperuricemia, and lactic acidosis. The canine model of GSDIa is naturally occurring and recapitulates almost all aspects of the human form of disease. We investigated the potential of recombinant adeno-associated virus (rAAV) vector-based therapy to treat the canine model of GSDIa. After delivery of a therapeutic rAAV2/8 vector to a 1-day-old GSDIa dog, improvement was noted as early as 2 weeks posttreatment. Correction was transient, however, and by 2 months posttreatment the rAAV2/8-treated dog could no longer sustain normal blood glucose levels after 1 hr of fasting. The same animal was then dosed with a therapeutic rAAV2/1 vector delivered via the portal vein. Two months after rAAV2/1 dosing, both blood glucose and lactate levels were normal at 4 hr postfasting. With more prolonged fasting, the dog still maintained near-normal glucose concentrations, but lactate levels were elevated by 9 hr, indicating that partial correction was achieved. Dietary glucose supplementation was discontinued starting 1 month after rAAV2/1 delivery and the dog continues to thrive with minimal laboratory abnormalities at 23 months of age (18 months after rAAV2/1 treatment). These results demonstrate that delivery of rAAV vectors can mediate significant correction of the GSDIa phenotype and that gene transfer may be a promising alternative therapy for this disease and other genetic diseases of the liver.
Staud R.,University of Florida
Expert Opinion on Pharmacotherapy | Year: 2011
Introduction: Gamma-hydroxybutyrate (GHB) is a short-chain fatty acid that is synthesized within the CNS, mostly from its parent compound gamma amino butyric acid (GABA). GHB acts as a neuromodulator/neurotransmitter to affect neuronal activity of other neurotransmitters and so, stimulate the release of growth hormone. Its sodium salt (sodium oxybate: SXB) was approved by the Food and Drug Administration (FDA) for the treatment of narcolepsy. SXB has shown to improve disrupted sleep and increase NR3 (slow-wave restorative) sleep in patients with narcolepsy. It is rapidly absorbed and has a plasma half-life of 30 60 min, necessitating twice-nightly dosing. Most of the observed effects of SXB result from binding to GABA-B receptors. Areas covered: Several randomized, controlled trials demonstrated significantly improved fibromyalgia (FM) symptoms with SXB. As seen in narcolepsy trials, SXB improved sleep of FM patients, increased slow-wave sleep duration as well as delta power, and reduced frequent night-time awakenings. Furthermore, FM pain and fatigue was consistently reduced with nightly SXB over time. Commonly reported adverse events included headache, nausea, dizziness and somnolence. Despite its proven efficacy, SXB did not receive FDA approval for the management of FM in 2010, mostly because of concerns about abuse. Expert opinion: Insomnia, fatigue and pain are important clinical FM symptoms that showed moderate improvements with SXB in several large, well-designed clinical trials. Because of the limited efficacy of currently available FM drugs additional treatment options are needed. In particular, drugs like SXB which belong to a different drug class than other Food and Drug Administration (FDA)-approved FM medications such as pregabalin, duloxetine and milnacipran would provide a much-needed addition to presently available treatment options. However, the FDA has set the bar high for future SXB re-submissions, with requirements of superior efficacy and improved risk mitigation strategies. At this time, no future FDA submission of SXB for the fibromyalgia indication is planned. © 2011 Informa UK, Ltd.
Jarrett S.G.,University of Kentucky |
Boulton M.E.,University of Florida
Molecular Aspects of Medicine | Year: 2012
The retina resides in an environment that is primed for the generation of reactive oxygen species (ROS) and resultant oxidative damage. The retina is one of the highest oxygen-consuming tissues in the human body. The highest oxygen levels are found in the choroid, but this falls dramatically across the outermost retina, creating a large gradient of oxygen towards the retina and inner segments of the photoreceptors which contain high levels of polyunsaturated fatty acids. This micro-environment together with abundant photosensitizers, visible light exposure and a high energy demand supports a highly oxidative milieu. However, oxidative damage is normally minimized by the presence of a range of antioxidant and efficient repair systems. Unfortunately, as we age oxidative damage increases, antioxidant capacity decreases and the efficiency of reparative systems become impaired. The result is retinal dysfunction and cell loss leading to visual impairment. It appears that these age-related oxidative changes are a hallmark of early age-related macular degeneration (AMD) which, in combination with hereditary susceptibility and other retinal modifiers, can progress to the pathology and visual morbidity associated with advanced AMD. This review reassesses the consequences of oxidative stress in AMD and strategies for preventing or reversing oxidative damage in retinal tissues. © 2012 Elsevier Ltd. All rights reserved.
Sefah K.,University of Florida
Nature protocols | Year: 2010
In the past two decades, high-affinity nucleic acid aptamers have been developed for a wide variety of pure molecules and complex systems such as live cells. Conceptually, aptamers are developed by an evolutionary process, whereby, as selection progresses, sequences with a certain conformation capable of binding to the target of interest emerge and dominate the pool. This protocol, cell-SELEX (systematic evolution of ligands by exponential enrichment), is a method that can generate DNA aptamers that can bind specifically to a cell type of interest. Commonly, a cancer cell line is used as the target to generate aptamers that can differentiate that cell type from other cancers or normal cells. A single-stranded DNA (ssDNA) library pool is incubated with the target cells. Nonbinding sequences are washed off and bound sequences are recovered from the cells by heating cell-DNA complexes at 95 degrees C, followed by centrifugation. The recovered pool is incubated with the control cell line to filter out the sequences that bind to common molecules on both the target and the control, leading to the enrichment of specific binders to the target. Binding sequences are amplified by PCR using fluorescein isothiocyanate-labeled sense and biotin-labeled antisense primers. This is followed by removal of antisense strands to generate an ssDNA pool for subsequent rounds of selection. The enrichment of the selected pools is monitored by flow cytometry binding assays, with selected pools having increased fluorescence compared with the unselected DNA library. The procedure, from design of oligonucleotides to enrichment of the selected pools, takes approximately 3 months.
Bashirullah R.,University of Florida
IEEE Microwave Magazine | Year: 2010
In vivo wireless biomedical microsystems fueled by the continued scaling of electronic components and the development of new micro sensors and micropackaging technologies is rapidly changing the landscape of the electronics and medical industry. These devices can be used for a myriad of monitoring, diagnostic, therapeutic, and interventional applications that range from the well known cardiac pacemakers and defibrillators to emerging applications in visual prosthesis, brain computer interfaces (BCIs), and embedded monitoring of a variety of medical useful variables such as oxygen, glucose, pH level, pressure, and core temperature. This article presents a brief overview of design considerations for implementing wireless power and data interfaces for in vivo biomedical devices. Examples of emerging implantable and ingestible wireless biomedical devices are discussed. © 2006 IEEE.
Meert J.G.,University of Florida
Gondwana Research | Year: 2014
The Ediacaran-Early Ordovician interval is of great interest to paleogeographer's due to the vast evolutionary changes that occurred during this interval as well as other global changes in the marine, atmospheric and terrestrial systems. It is; however, precisely this time period where there are often wildly contradictory paleomagnetic results from similar-age rocks. These contradictions are often explained with a variety of innovative (and non-uniformitarian) scenarios such as intertial interchange true polar wander, true polar wander and/or non-dipolar magnetic fields. While these novel explanations may be the cause of the seemingly contradictory data, it is important to examine the paleomagnetic database for other potential issues.This review takes a careful and critical look at the paleomagnetic database from Baltica. Based on some new data and a re-evaluation of older data, the relationships between Baltica and Laurentia are examined for ~. 600-500. Ma interval. The new data from the Hedmark Group (Norway) confirms suspicions about possible remagnetization of the Fen Complex pole. For other Baltica results, data from sedimentary units were evaluated for the effects of inclination shallowing. In this review, a small correction was applied to sedimentary paleomagnetic data from Baltica. The filtered dataset does not demand extreme rates of latitudinal drift or apparent polar wander, but it does require complex gyrations of Baltica over the pole. In particular, average rates of APW range from 1.5° to 2.0°/Myr. This range of APW rates is consistent with 'normal' plate motion although the total path length (and its oscillatory nature) may indicate a component of true polar wander. In the TPW scenario, the motion of Baltica results in a back and forth path over the south pole between 600 and 550. Ma and again between 550 and 500. Ma. The rapid motion of Baltica over the pole is consistent with the extant database, but other explanations are possible given the relative paucity of high-quality paleomagnetic data during the Ediacaran-Cambrian interval from Baltica and other continental blocks.A sequence of three paleogeographic maps for Laurentia and Baltica is presented. Given the caveats involved in these reconstructions (polarity ambiguity, longitudinal uncertainty and errors), the data are consistent with geological models that posit the opening of the Iapetus Ocean around 600. Ma and subsequent evolution of the Baltica-Laurentia margin in the Late Ediacaran to Early Ordovician, but the complexity of the motion implied by the APWP remains enigmatic. © 2012 International Association for Gondwana Research.
Detweiler S.,University of Florida
Mass and Motion in General Relativity | Year: 2011
The gravitational field of a particle of small mass m moving through curved spacetime, with metric g ab, is naturally and easily decomposed into two parts each of which satisfies the perturbed Einstein equations through O(m). One part is an inhomogeneous field h ab S which, near the particle, looks like the Coulomb m â̂? r field with tidal distortion from the local Riemann tensor. This singular field is defined in a neighborhood of the small particle and does not depend upon boundary conditions or upon the behavior of the source in either the past or the future. The other part is a homogeneous field h ab R. In a perturbative analysis, the motion of the particle is then best described as being a geodesic in the metric g ab + h ab R. This geodesic motion includes all of the effects which might be called radiation reaction and conservative effects as well. © 2011 Springer Science+Business Media B.V.
Morris Jr. J.G.,University of Florida
Emerging Infectious Diseases | Year: 2011
Cholera has affected humans for at least a millennium and persists as a major cause of illness and death worldwide, with recent epidemics in Zimbabwe (2008-2009) and Haiti (2010). Clinically, evidence exists of increasing severity of disease linked with emergence of atypical Vibrio cholerae organisms that have incorporated genetic material from classical biotype strains into an El Tor biotype background. A key element in transmission may be a recently recognized hyper infectious phase, which persists for hours after passage in diarrheal feces. We propose a model of transmission in which environmental triggers (such as temperature) lead to increases in V. cholerae in environmental reservoirs, with spillover into human populations. However, once the microorganism is introduced into a human population, transmission occurs primary by "fast" transmission from person to person (taking advantage of the hyper infectious state), without returning to the aquatic environment.
Staud R.,University of Florida
Drugs | Year: 2010
Fibromyalgia is a chronic pain disorder characterized by widespread pain, stiffness, insomnia, fatigue and distress. Several randomized controlled trials (RCTs) have shown moderate effectiveness of pharmacological therapies for fibromyalgia pain. Evidence from these trials suggests that pharmacological therapy can not only improve pain but also fatigue, function and well-being in patients with fibromyalgia. Duloxetine and milnacipran, two highly selective serotonin-norepinephrine (noradrenaline) reuptake inhibitors, and the α2δ agonist pregabalin have been approved by the US FDA for the treatment of fibromyalgia symptoms. In general, about half of all treated patients seem to experience a 30 reduction of symptoms, suggesting that many patients with fibromyalgia will require additional therapies. Thus, other forms of treatment, including exercise, cognitive behavioural therapies and self-management strategies, may be necessary to achieve satisfactory treatment outcomes.Despite promising results of pilot trials, RCTs with dopamine receptor agonists and sodium channel antagonists have so far been disappointing for patients with fibromyalgia. However, new pharmacological approaches for the treatment of fibromyalgia pain and insomnia using sodium oxybate appear to be promising. © 2010 Adis Data Information BV. All rights reserved.
Uchihara T.,Tokyo Metropolitan Institute of Medical Science |
Giasson B.I.,University of Florida
Acta Neuropathologica | Year: 2016
Progressive aggregation of alpha-synuclein (αS) through formation of amorphous pale bodies to mature Lewy bodies or in neuronal processes as Lewy neurites may be the consequence of conformational protein changes and accumulations, which structurally represents “molecular template”. Focal initiation and subsequent spread along anatomically connected structures embody “structural template”. To investigate the hypothesis that both processes might be closely associated and involved in the progression of αS pathology, which can be observed in human brains, αS amyloidogenic precursors termed “seeds” were experimentally injected into the brain or peripheral nervous system of animals. Although these studies showed that αS amyloidogenic seeds can induce αS pathology, which can spread in the nervous system, the findings are still not unequivocal in demonstrating predominant transsynaptic or intraneuronal spreads either in anterograde or retrograde directions. Interpretation of some of these studies is further complicated by other concurrent aberrant processes including neuroimmune activation, injury responses and/or general perturbation of proteostasis. In human brain, αS deposition and neuronal degeneration are accentuated in distal axon/synapse. Hyperbranching of axons is an anatomical commonality of Lewy-prone systems, providing a structural basis for abundance in distal axons and synaptic terminals. This neuroanatomical feature also can contribute to such distal accentuation of vulnerability in neuronal demise and the formation of αS inclusion pathology. Although retrograde progression of αS aggregation in hyperbranching axons may be a consistent feature of Lewy pathology, the regional distribution and gradient of Lewy pathology are not necessarily compatible with a predictable pattern such as upward progression from lower brainstem to cerebral cortex. Furthermore, “focal Lewy body disease” with the specific isolated involvement of autonomic, olfactory or cardiac systems suggests that spread of αS pathology is not always consistent. In many instances, the regional variability of Lewy pathology in human brain cannot be explained by a unified hypothesis such as transsynaptic spread. Thus, the distribution of Lewy pathology in human brain may be better explained by variable combinations of independent focal Lewy pathology to generate “multifocal Lewy body disease” that could be coupled with selective but variable neuroanatomical spread of αS pathology. More flexible models are warranted to take into account the relative propensity to develop Lewy pathology in different Lewy-prone systems, even without interconnections, compatible with the expanding clinicopathological spectra of Lewy-related disorders. These revised models are useful to better understand the mechanisms underlying the variable progression of Lewy body diseases so that diagnostic and therapeutic strategies are improved. © 2015, The Author(s).
Lewis J.,University of Florida
Acta Neuropathologica | Year: 2016
Tau is a microtubule-associated protein and a key regulator of microtubule stabilization as well as the main component of neurofibrillary tangles—a principle neuropathological hallmark of Alzheimer’s disease (AD)—as well as pleomorphic neuronal and glial inclusions in neurodegenerative tauopathies. Cross-sectional studies of neurofibrillary pathology in AD reveal a stereotypic spatiotemporal pattern of neuronal vulnerability that correlates with disease severity; however, the relationship of this pattern to disease progression is less certain and exceptions to the typical pattern have been described in a subset of AD patients. The basis for the selective vulnerability of specific populations of neurons to tau pathology and cell death is largely unknown, although there have been a number of hypotheses based upon shared properties of vulnerable neurons (e.g., degree of axonal myelination or synaptic plasticity). A recent hypothesis for selective vulnerability takes into account the emerging science of functional connectivity based upon resting state functional magnetic resonance imaging, where subsets of neurons that fire synchronously define patterns of degeneration similar to specific neurodegenerative disorders, including various tauopathies. In the past 6 years, the concept of tau propagation has emerged from numerous studies in cell and animal models suggesting that tau moves from cell-to-cell and that this may trigger aggregation and region-to-region spread of tau pathology within the brain. How the spread of tau pathology relates to functional connectivity is an area of active investigation. Observations of templated folding and propagation of tau have prompted comparisons of tau to prions, the pathogenic proteins in transmissible spongiform encephalopathies. In this review, we discuss the most compelling studies in the field, discuss their shortcomings and consider their implications with respect to human tauopathies as well as the controversy that tauopathies may be prion-like disorders. © 2015, Springer-Verlag Berlin Heidelberg.
Buchler J.R.,University of Florida |
Kollath Z.,Konkoly Observatory
Astrophysical Journal | Year: 2011
The Blazhko effect is a long-term, generally irregular modulation of the light curves that occurs in a sizeable number of RR Lyrae stars. The physical origin of the effect has been a puzzle ever since its discovery over a hundred years ago. We build here upon the recent observational and theoretical work of Szabó etal. on RRab stars who found with hydrodynamical simulations that the fundamental pulsation mode can get destabilized by a 9:2 resonant interaction with the 9th overtone. Alternating pulsation cycles arise, although these remain periodic, i.e., not modulated as in the observations. Here we use the amplitude equation formalism to study this nonlinear, resonant interaction between the two modes. We show that not only does the fundamental pulsation mode break up into a period-two cycle through the nonlinear, resonant interaction with the overtone, but that the amplitudes are modulated, and that in a broad range of parameters the modulations are irregular as in the observations. This irregular behavior is in fact chaotic and arises from a strange attractor in the dynamics. © 2011. The American Astronomical Society. All rights reserved.
Tan J.C.,University of Florida
Astrophysical Journal Letters | Year: 2010
We use observations of the radial profiles of the mass surface density of total, Σg, and molecular, ΣH2, gas rotation velocity and star formation rate surface density, Σsfr, of the molecular dominated regions of 12 disk galaxies from Leroy et al. to test several star formation laws: a "Kennicutt-Schmidt power law," Σsfr = Ag Σ1.5 g,2; a "constant molecular law," Σsfr = A H2ΣH2,2; the "turbulence-regulated laws" of Krumholz & McKee (KM) and Krumholz, McKee, & Tumlinson (KMT), a "gas-Ω law," Σsfr = B ΩΣ gΩ; and a shear-driven "giant molecular cloud (GMC) collisions law," Σsfr = B CCΣ gΩ(1 - 0.7β), where β ≡ d ln v circ/d ln r. We find the constant molecular law, KMT turbulence law, and GMC collision law are the most accurate, with an rms error of a factor of 1.5 if the normalization constants are allowed to vary between galaxies. Of these three laws, the GMC collision law does not require a change in physics to account for the full range of star formation activity seen from normal galaxies to circumnuclear starbursts. A single global GMC collision law with B CC = 8.0 × 10-3, i.e., a gas consumption time of 20 orbital times for β = 0, yields an rms error of a factor of 1.8. © 2010. The American Astronomical Society. All rights reserved.
Benson H.P.,University of Florida
Journal of Global Optimization | Year: 2015
This article presents a branch and bound algorithm for globally solving the nonlinear sum of ratios problem (P). The algorithm works by globally solving a sum of ratios problem that is equivalent to problem (P). In the algorithm, upper bounds are computed by maximizing concave envelopes of a sum of ratios function over intersections of the feasible region of the equivalent problem with rectangular sets. The rectangular sets are systematically subdivided as the branch and bound search proceeds. Two versions of the algorithm, with convergence results, are presented. Computational advantages of these algorithms are indicated, and some computational results are given that were obtained by globally solving some sample problems with one of these algorithms. © 2002Kluwer Academic Publishers.Printed in the Netherlands.
Garvan F.G.,University of Florida
Journal of Combinatorial Theory. Series A | Year: 2015
Recently Andrews and Sellers proved some amazing congruences for the Fishburn numbers. We extend their results to a more general sequence of numbers. As a result we prove a new congruence mod 23 for the Fishburn numbers and prove their conjectured mod 5 congruence for a related sequence. We also extend and prove some unpublished conjectures of Garthwaite and Rhoades. © 2015 Elsevier Inc.
Ritter G.X.,University of Florida |
Urcid G.,National Institute of Astrophysics, Optics and Electronics
Information Sciences | Year: 2011
In this manuscript we propose a method for the autonomous determination of endmembers in hyperspectral imagery based on recent theoretical advancements on lattice auto-associative memories. Given a hyperspectral image, the lattice algebra approach finds in a single-pass all possible candidate endmembers from which various affinely independent sets of final endmembers may be derived. In contrast to other endmember detection methods, the endmembers found using two dual canonical lattice matrices are geometrically linked to the data set spectra. The mathematical foundation of the proposed method is first described in some detail followed by application examples that illustrate the key steps of the proposed lattice based method. © 2010 Elsevier Inc. All rights reserved.
Khan S.R.,University of Florida
Urological Research | Year: 2010
Nephrocalcinosis is the deposition of calcium salts in renal parenchyma and can be intratubular or interstitial. Animal model studies indicate that intratubular nephrocalcinosis is a result of increased urinary supersat uration. Urinary supersaturation with respect to calcium oxalate (CaOx) and calcium phosphate (CaP) are generally achieved at different locations in the renal tubules. As a result experimental induction of hyperoxaluria in animals with CaP deposits does not lead to growth of CaOx over CaP. Interstitial nephrocalcinosis has been seen in mice with lack of crystallization modulators Tamm-Horsfall protein and osteopontin. Sodium phosphate co-transporter or sodiumhydrogen exchanger regulator factor-1 null mice also produced interstitial nephrocalcinosis. Crystals plug the tubules by aggregating and attaching to the luminal cell surface. Structural features of the renal tubules also play a role in crystal retention. The crystals plugging the terminal collecting ducts when exposed to the metastable pelvicurine may promote the formation of stone. © Springer-Verlag 2010.
Hong J.,Duke University |
Luesch H.,University of Florida
Natural Product Reports | Year: 2012
Covering up to 2011 The cyclic depsipeptide largazole from a cyanobacterium of the genus Symploca is a marine natural product with a novel chemical scaffold and potently inhibits class I histone deacetylases (HDACs). Largazole possesses highly differential growth-inhibitory activity, preferentially targeting transformed over non-transformed cells. The intriguing structure and biological activity of largazole have attracted strong interest from the synthetic chemistry community to establish synthetic routes to largazole and to investigate its potential as a cancer therapeutic. This Highlight surveys recent advances in this area with a focus on the discovery, synthesis, target identification, structure-activity relationships, HDAC8-largazole thiol crystal structure, and biological studies, including in vivo anticancer and osteogenic activities. This journal is © The Royal Society of Chemistry 2012.
Tasker E.J.,McMaster University |
Tasker E.J.,University of Florida
Astrophysical Journal | Year: 2011
We investigate the effect of star formation and diffuse photoelectric heating on the properties of giant molecular clouds (GMCs) formed in high-resolution (≲10pc) global (∼20kpc) simulations of isolated Milky-Way-type galaxy disks. The clouds are formed through gravitational fragmentation, and structures with densities n H,c>100 cm -3 are identified as GMCs. Between 1000 and 1500 clouds are created in the simulations with masses M>105 M 1 and 180-240 with masses M>106 M ⊙ in agreement with estimates of the Milky Way's population. We find that the effect of photoelectric heating is to suppress the fragmentation of the interstellar medium, resulting in a filamentary structure in the warm gas surrounding clouds. This environment suppresses the formation of a retrograde rotating cloud population, with 88% of the clouds rotating prograde with respect to the galaxy after 300Myr. The diffuse heating also reduces the initial star formation rate (SFR), slowing the conversation of gas into stars. We therefore conclude that the interstellar environment plays an important role in the GMC evolution. Our clouds live between 0 and 20Myr with a high infant mortality (t′ < 3Myr) due to cloud mergers and star formation. Other properties, including distributions of mass, size, and surface density, agree well with observations. Collisions between our clouds are common, occurring at a rate of ∼ 1/4 of the orbital period. It is not clear whether such collisions trigger or suppress star formation at our current resolution. Our SFR is a factor of 10 higher than observations in local galaxies. This is likely due to the absence of localized feedback in our models. © 2011. The American Astronomical Society. All rights reserved.
Davis T.A.,University of Florida
ACM Transactions on Mathematical Software | Year: 2011
SuiteSparseQR is a sparse QR factorization package based on the multifrontal method. Within each frontal matrix, LAPACK and the multithreaded BLAS enable the method to obtain high performance on multicore architectures. Parallelism across different frontalmatrices is handled with Intel's Threading Building Blocks library. The symbolic analysis and ordering phase pre-eliminates singletons by permuting the input matrix Ainto the form [R 11 R 12; 0 A 22] where R 11 is upper triangular with diagonal entries above a given tolerance. Next, the fill-reducing ordering, column elimination tree, and frontal matrix structures are found without requiring the formation of the pattern of A T A. Approximate rank-detection is performed within each frontal matrix usingHeath's method.While Heath'smethod is not always exact, it has the advantage of not requiring column pivoting and thus does not interfere with the fill-reducing ordering. For sufficiently large problems, the resulting sparse QR factorization obtains a substantial fraction of the theoretical peak performance of a multicore computer. © 2011 ACM 0098-3500/2011/11-ART8.
Conrad K.P.,Florida College |
Conrad K.P.,University of Florida
American Journal of Physiology - Regulatory Integrative and Comparative Physiology | Year: 2011
Pregnancy is a unique physiological condition of profound maternal renal and systemic vasodilation. Our goal has been to unveil the reproductive hormones mediating this remarkable vasodilatory state and the underlying molecular mechanisms. In addition to advancing our knowledge of pregnancy physiology, reaching this goal may translate into therapeutics for pregnancy pathologies such as preeclampsia and for diseases associated with vasoconstriction and arterial stiffness in nonpregnant women and men. An emerging player is the 6 kDa corpus luteal hormone relaxin, which circulates during pregnancy. Relaxin administration to rats and humans induces systemic and renal vasodilation regardless of sex, thus mimicking the pregnant condition. Immunoneutralization or elimination of the source of circulating relaxin prevents renal and systemic vasodilation in midterm pregnant rats. Infertile women who become pregnant by donor eggs (IVF with embryo transfer) lack a corpus luteum and circulating relaxin, and they show a markedly subdued gestational increase in glomerular filtration rate. These data implicate relaxin as one of the vasodilatory reproductive hormones of pregnancy. There are different molecular mechanisms underlying the so-called rapid and sustained vasodilatory actions of relaxin. The former is mediated by Gαi/o protein coupling to phosphatidylinositol-3 kinase/Akt (protein kinase B)-dependent phosphorylation and activation of endothelial nitric oxide synthase, the latter by vascular endothelial and placental growth factors, and increases in arterial gelatinase(s) activity. The gelatinases, in turn, hydrolyze big endothelin (ET) at a gly-leu bond to form ET1-32, which activates the endothelial ETB receptor/nitric oxide vasodilatory pathway. © 2011 the American Physiological Society.
Tanner D.B.,University of Florida
Physical Review B - Condensed Matter and Materials Physics | Year: 2015
Kramers-Kronig analysis is commonly used to estimate the optical properties of new materials. The analysis typically uses data from far infrared through near ultraviolet (say 40-40000cm-1 or 5 meV-5 eV) and uses extrapolations outside the measured range. Most high-frequency extrapolations use a power law, 1/ωn, transitioning to 1/ω4 at a considerably higher frequency and continuing this free-carrier extension to infinity. The midrange power law is adjusted to match the slope of the data and to give pleasing curves, but the choice of power (usually between 0.5 and 3) is arbitrary. Instead of an arbitrary power law, it is better to use x-ray atomic scattering functions such as those presented by Henke and co-workers. These basically treat the solid as a linear combination of its atomic constituents and, knowing the chemical formula and the density, allow the computation of dielectric function, reflectivity, and other optical functions. The "Henke reflectivity" can be used over photon energies of 10 eV to 34 keV, after which a 1/ω4 continuation is perfectly fine. The bridge between experimental data and the Henke reflectivity as well as two corrections made to the latter are discussed. © 2015 American Physical Society.
Graber J.A.,University of Florida
Hormones and Behavior | Year: 2013
This article is part of a Special Issue "Puberty and Adolescence".This paper examines consistency of effects of pubertal timing (going through puberty earlier, later or at the same time one's cohort of peers) on the development of psychopathology during adolescence as well as the persistence of effects into adulthood. It is argued that early maturing girls are at unique risk for psychopathology not only in terms of elevated internalizing and externalizing symptoms and disorders during adolescence but also persistence of elevated risk for depressive disorders and other symptomatology in adulthood. Emerging evidence supports bio-psychosocial pathways for these effects. In addition, recent evidence indicates that late maturation in males may also be a pathway for psychopathology typified by elevated symptoms of psychopathology during early and mid-adolescence and the emergence of disorder in the late adolescent period. While less well established, potential pathways for this association are also discussed. © 2013 Elsevier Inc..
Orrock J.L.,Washington University in St. Louis |
Holt R.D.,University of Florida |
Baskett M.L.,University of California at Davis
Ecology Letters | Year: 2010
At the intersection of consumer behaviour and plant competition is the concept of refuge-mediated apparent competition: an indirect interaction whereby plants provide a refuge for a shared consumer, subsequently increasing consumer pressure on another plant species. Here, we use a simple model and empirical examples to develop and illustrate the concept of refuge-mediated apparent competition. We find that the likelihood that an inferior competitor will succeed via refuge-mediated apparent competition is greater when competitors have similar resource requirements and when consumers exhibit a strong response to the refuge and high attack rates on the superior competitor. Refuge-mediated apparent competition may create an emergent Allee effect, such that a species invades only if it is sufficiently abundant to alter consumer impact on resident species. This indirect interaction may help explain unresolved patterns observed in biological invasion, such as the different physical structure of invasive exotic plants, the lag phase, and the failure of restoration efforts. Given the ubiquity of refuge-seeking behaviour by consumers and the ability of consumers to alter the outcome of direct competition among plants, refuge-mediated apparent competition may be an underappreciated mechanism affecting the composition and diversity of plant communities. © 2009 Blackwell Publishing Ltd/CNRS.
Bluck S.,University of Florida
Memory | Year: 2015
This special issue showcases research from around the world that takes a functional approach to autobiographical remembering. In doing so, it inspires researchers to reach out to new populations. This commentary begins with a brief history of the functional approach. Person–environment interactions, in this case how individuals use memory in their current cultural context, are at the core of that approach. Based on current theoretical thinking in this area, I review the papers in this issue with the aim of exploring: (1) where culture and function might fit in current conceptualisations of autobiographical memory, (2) the relation of culture to socio-structural variables such as gender and life phase in shaping the functions of memory and (3) differences in cultural tendencies to use autobiographical memory as a resource to fulfil universal human needs. © 2015 Taylor & Francis.
Nelson T.,Los Alamos National Laboratory |
Fernandez-Alberti S.,National University of Quilmes |
Roitberg A.E.,University of Florida |
Tretiak S.,Los Alamos National Laboratory
Accounts of Chemical Research | Year: 2014
ConspectusTo design functional photoactive materials for a variety of technological applications, researchers need to understand their electronic properties in detail and have ways to control their photoinduced pathways. When excited by photons of light, organic conjugated materials (OCMs) show dynamics that are often characterized by large nonadiabatic (NA) couplings between multiple excited states through a breakdown of the Born-Oppenheimer (BO) approximation. Following photoexcitation, various nonradiative intraband relaxation pathways can lead to a number of complex processes. Therefore, computational simulation of nonadiabatic molecular dynamics is an indispensable tool for understanding complex photoinduced processes such as internal conversion, energy transfer, charge separation, and spatial localization of excitons.Over the years, we have developed a nonadiabatic excited-state molecular dynamics (NA-ESMD) framework that efficiently and accurately describes photoinduced phenomena in extended conjugated molecular systems. We use the fewest-switches surface hopping (FSSH) algorithm to treat quantum transitions among multiple adiabatic excited state potential energy surfaces (PESs). Extended molecular systems often contain hundreds of atoms and involve large densities of excited states that participate in the photoinduced dynamics. We can achieve an accurate description of the multiple excited states using the configuration interaction single (CIS) formalism with a semiempirical model Hamiltonian. Analytical techniques allow the trajectory to be propagated "on the fly" using the complete set of NA coupling terms and remove computational bottlenecks in the evaluation of excited-state gradients and NA couplings. Furthermore, the use of state-specific gradients for propagation of nuclei on the native excited-state PES eliminates the need for simplifications such as the classical path approximation (CPA), which only uses ground-state gradients. Thus, the NA-ESMD methodology offers a computationally tractable route for simulating hundreds of atoms on ∼10 ps time scales where multiple coupled excited states are involved.In this Account, we review recent developments in the NA-ESMD modeling of photoinduced dynamics in extended conjugated molecules involving multiple coupled electronic states. We have successfully applied the outlined NA-ESMD framework to study ultrafast conformational planarization in polyfluorenes where the rate of torsional relaxation can be controlled based on the initial excitation. With the addition of the state reassignment algorithm to identify instances of unavoided crossings between noninteracting PESs, NA-ESMD can now be used to study systems in which these so-called trivial unavoided crossings are expected to predominate. We employ this technique to analyze the energy transfer between poly(phenylene vinylene) (PPV) segments where conformational fluctuations give rise to numerous instances of unavoided crossings leading to multiple pathways and complex energy transfer dynamics that cannot be described using a simple Förster model. In addition, we have investigated the mechanism of ultrafast unidirectional energy transfer in dendrimers composed of poly(phenylene ethynylene) (PPE) chromophores and have demonstrated that differential nuclear motion favors downhill energy transfer in dendrimers. The use of native excited-state gradients allows us to observe this feature. © 2014 American Chemical Society.
Galasko D.,University of California at San Diego |
Golde T.E.,University of Florida
Alzheimer's Research and Therapy | Year: 2013
Substances produced throughout the body are detectable in the blood, which is the most common biological fluid used in clinical testing. Biomarkers for Alzheimer's disease (AD) have long been sought in the blood, but none has become an established or validated diagnostic test. Companion reviews in Alzheimer's Research & Therapy will review specific types of biomarkers or applications; in this overview, we cover key concepts related to AD blood biomarker studies in general. Reasons for the difficulty of detecting markers of a brain-specific disorder, such as AD, in the blood are outlined; these pose conceptual challenges for blood biomarker discovery and development. Applications of blood tests in AD go beyond screening and diagnostic testing; other potential uses are risk assessment, prognostication, and evaluation of treatment target engagement, toxicity, and outcome. Opportunities and questions that may surround these different uses are discussed. A systematic approach to biomarker discovery, detection, assay development and quality control, sample collection, handling and storage, and design and analysis of clinical studies needs to be implemented at every step of discovery and translation to identify an interpretable and useful biomarker. © 2013 BioMed Central Ltd.
Dutta S.,University of Florida
ChemSusChem | Year: 2012
Say no to O: The catalytic deoxygenation of biomass-derived feedstocks (sugars, sugar alcohols) is a promising pathway towards a sustainable chemical production economy. The development of efficient synthetic protocols for oxygen removal is highly desirable to derive chemical building blocks and fuels. A major challenge is selection/design of effective catalysts. This Highlight appraises the hurdles and opportunities for deoxygenation of biomass feedstocks. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Iovine N.M.,University of Florida
Virulence | Year: 2013
Campylobacter jejuni is a major cause of food-borne gastroenteritis worldwide. While mortality is low, morbidity imparted by post-infectious sequelae such as Guillain-Barré syndrome, Reiter syndrome/reactive arthritis and irritable bowel syndrome is significant. In addition, the economic cost is high due to lost productivity. Food animals, particularly poultry, are the main reservoirs of C. jejuni. The over-use of antibiotics in the human population and in animal husbandry has led to an increase in antibiotic-resistant infections, particularly with fluoroquinolones. This is problematic because C. jejuni gastroenteritis is clinically indistinguishable from that caused by other bacterial pathogens, and such illnesses are usually treated empirically with fluoroquinolones. Since C. jejuni is naturally transformable, acquisition of additional genes imparting antibiotic resistance is likely. Therefore, an understanding of the antibiotic resistance mechanisms in C. jejuni is needed to provide proper therapy both to the veterinary and human populations. © 2013 Landes Bioscience.
Stellefson M.,University of Florida
Journal of medical Internet research | Year: 2012
The current "Millennial Generation" of college students majoring in the health professions has unprecedented access to the Internet. Although some research has been initiated among medical professionals to investigate the cognitive basis for health information searches on the Internet, little is known about Internet search practices among health and medical professional students. To systematically identify health professional college student perspectives of personal eHealth search practices. Q methodology was used to examine subjective perspectives regarding personal eHealth search practices among allied health students majoring in a health education degree program. Thirteen (n = 13) undergraduate students were interviewed about their attitudes and experiences conducting eHealth searches. From the interviews, 36 statements were used in a structured ranking task to identify clusters and determine which specific perceptions of eHealth search practices discriminated students into different groups. Scores on an objective measure of eHealth literacy were used to help categorize participant perspectives. Q-technique factor analysis of the rankings identified 3 clusters of respondents with differing views on eHealth searches that generally coincided with participants' objective eHealth literacy scores. The proficient resourceful students (pattern/structure coefficient range 0.56-0.80) described themselves as using multiple resources to obtain eHealth information, as opposed to simply relying on Internet search engines. The intermediate reluctant students (pattern/structure coefficient range 0.75-0.90) reported engaging only Internet search engines to locate eHealth information, citing undeveloped evaluation skills when considering sources of information located on the Internet. Both groups of advanced students reported not knowing how to use Boolean operators to conduct Internet health searches. The basic hubristic students (pattern/structure coefficient range 0.54-0.76) described themselves as independent procrastinators when searching for eHealth information. Interestingly, basic hubristic students represented the only cluster of participants to describe themselves as (1) having received instruction on using the Internet to conduct eHealth searches, and (2) possessing relative confidence when completing a search task. Subjective perspectives of eHealth search practices differed among students possessing different levels of eHealth literacy. These multiple perspectives present both challenges and opportunities for empowering college students in the health professions to use the Internet to obtain and appraise evidence-based health information using the Internet.
Cheng S.X.,University of Florida
World Journal of Gastroenterology | Year: 2016
Management of acute diarrhea remains a global challenge, particularly in resource-limiting countries. Oral rehydration solution (ORS), a passive rehydrating therapy developed approximately 40 years ago, remains the mainstay treatment. Although ORS is effective for hydration, since it does not inhibit enterotoxinmediated excessive secretion, reduced absorption and compromised barrier function-the primary mechanisms of diarrhea, ORS does not offer a rapid relief of diarrhea symptom. There are a few alternative therapies available, yet the use of these drugs is limited by their expense, lack of availability and/or safety concerns. Novel anti-diarrheal therapeutic approaches, particularly those simple affordable therapies, are needed. This article explores intestinal calciumsensing receptor (CaSR), a newly uncovered target for therapy of diarrhea. Unlike others, targeting this host antidiarrheal receptor system appears all-inclusive: it is anti-secretory, pro-absorptive, anti-motility, and anti-inflammatory. Thus, activating CaSR reverses changes of both secretory and inflammatory diarrheas. Considering its unique property of using simple nutrients such as calcium, polyamines, and certain amino acids/oligopeptides as activators, it is possible that through targeting of CaSR with a combination of specific nutrients, novel oral rehydrating solutions that are inexpensive and practical to use in all countries may be developed. © The Author(s) 2016.
Dobson J.,Keele University |
Dobson J.,University of Florida
Nature Materials | Year: 2010
Some of the challenges involved in modifying the concept of using magnetic micro- and nanoparticles for targeting solid tumors with drugs are discussed. The technology has been modified taking advantage of a different approach to using magnetic particles for treatment. The new technology has the potential to overcome many of the challenges involved in practical application of magnetic targeting in clinical environments. A team of researchers has reported its method for exploiting spin vortices in magnetic discs to mechanically trigger the destruction of cancer cells. Cell death can also be induced at much lower magnetic fields and frequencies by using a mechanical mechanism, reducing potential side effects. One of the reasons that magnetic drug targeting has failed to realize its potential is that the magnetic fields generated by permanent magnets or electromagnets reduce rapidly with distance to the target tissue.
Dobson J.L.,University of Florida
American Journal of Physiology - Advances in Physiology Education | Year: 2010
Students have learning style preferences that are often classified according to their visual (V), aural (A), read-write (R), and/or kinesthetic (K) sensory modality preferences (SMP). The purposes of this investigation were to compare student perceived and assessed SMPs and examine the associations between those SMPs and status (i.e., undergraduates vs. graduates), sex, and course performance. Students from the fall 2009 APK 3110 and APK 6116 Exercise Physiology courses were asked to indicate their perceived SMPs and complete the standard VARK SMP assessment. There were 64 student respondents: 50 undergraduates and 14 graduates (40 women and 24 men). According to the perceived SMP results, the largest number of respondents chose V (36%), followed by R (28%), K (19%), and A (17%). In terms of assessed SMPs, the largest number of respondents were classified as VARK (37%), followed by R (14%), AK (11%), K (8%), VK (6%), ARK (6%), A (5%), VAK (3%), RK (3%), V (2%), AR (2%), and VRK (2%). Nearly two-thirds of the respondents correctly matched their perceived and dominant assessed SMP. There was no statistical association between SMP and status. There was a very nearly significant relationship between sex and both perceived (χ2 = 7.18, P = 0.06) and assessed (χ2 = 17.36, P = 0.09) SMP. Finally, there was a significant relationship between perceived SMP and course scores (P = 0.01 by ANOVA). Post hoc tests revealed that the K group scored significantly lower than the other three modality groups. © 2010 The American Physiological Society.
Su N.-Y.,University of Florida
Journal of Economic Entomology | Year: 2013
The reliability of the capture probability equilibrium model developed by Su and Lee (2008) for population estimate was tested in three-directional extended foraging arenas connecting to large Plexiglas cubes (96 by 96 by 96 cm) containing ≈100,000-400,000 workers of the Formosan subterranean termite, Coptotermes formosanus Shiraki. After the release of marked termites in the arenas, the capture probability was averaged for three directions at equal distance from the release point. The daily data of directionally averaged capture probability were subject to a linear regression with distance as the independent variable to identify the capture probability equilibrium. When the daily data produced significant regressions with regression slope |b| ≤ 0.05 or |b| ≈ 0.05, the directionally averaged capture probability was considered to have reached equilibrium, and the regression intercept was used in the Lincoln index to derive the population estimate. Of the four laboratory colonies tested, three met the criteria, and the equilibrium models yielded population estimates that were not significantly different from the known numbers of workers in the arenas. © 2013 Entomological Society of America.
Hagen S.J.,University of Florida
Current Protein and Peptide Science | Year: 2010
The famous Kramers rate theory for diffusion-controlled reactions has been extended in numerous ways and successfully applied to many types of reactions. Its application to protein folding reactions has been of particular interest in recent years, as many researchers have performed experiments and simulations to test whether folding reactions are diffusion-controlled, whether the solvent is the source of the reaction friction, and whether the friction-dependence of folding rates generally can provide insight into folding dynamics. These experiments involve many practical difficulties, however. They have also produced some unexpected results. Here we briefly review the Kramers theory for reactions in the presence of strong friction and summarize some of the subtle problems that arise in the application of the theory to protein folding. We discuss how the results of these experiments ultimately point to a significant role for internal friction in protein folding dynamics. Studies of friction in protein folding, far from revealing any weakness in Kramers theory, may actually lead to new approaches for probing diffusional dynamics and energy landscapes in protein folding. © 2010 Bentham Science Publishers Ltd.
Miller S.A.,University of Florida
ACS Macro Letters | Year: 2013
The field of sustainable polymers is growing and evolving at unprecedented rates. Researchers are increasingly concerned with the feedstock origins and the degradation behavior of, especially, large-scale commodity packaging plastics. A perspective is offered here for the design of sustainable polymers, specifically addressing opportunities for monomer development and polymer degradation. Key concepts include: water degradability instead of biodegradability; incorporation of novel main-chain functionality, such as acetals; utilization of lignin-based aromatics; and direct polymerization of biogenic C1 feedstocks. © 2013 American Chemical Society.
Conlon T.J.,University of Florida
Human gene therapy. Clinical development | Year: 2013
Abstract Proof of concept for MERTK gene replacement therapy has been demonstrated using different viral vectors in the Royal College of Surgeon (RCS) rat, a well characterized model of recessive retinitis pigmentosa that contains a mutation in the Mertk gene. MERTK plays a key role in renewal of photoreceptor outer segments (OS) by phagocytosis of shed OS tips. Mutations in MERTK cause impaired phagocytic activity and accumulation of OS debris in the interphotoreceptor space that ultimately leads to photoreceptor cell death. In the present study, we conducted a series of preclinical potency and GLP-compliant safety evaluations of an adeno-associated virus type 2 (AAV2) vector expressing human MERTK cDNA driven by the retinal pigment epithelium-specific, VMD2 promoter. We demonstrate the potency of the vector in RCS rats by improved electroretinogram (ERG) responses in treated eyes compared with contralateral untreated controls. Toxicology and biodistribution studies were performed in Sprague-Dawley (SD) rats injected with two different doses of AAV vectors and buffer control. Delivery of vector in SD rats did not result in a change in ERG amplitudes of rod and cone responses relative to balanced salt solution control-injected eyes, indicating that administration of AAV vector did not adversely affect normal retinal function. In vivo fundoscopic analysis and postmortem retinal morphology of the vector-injected eyes were normal compared with controls. Evaluation of blood smears showed the lack of transformed cells in the treated eyes. All injected eyes and day 1 blood samples were positive for vector genomes, and all peripheral tissues were negative. Our results demonstrate the potency and safety of the AAV2-VMD2-hMERTK vector in animal models tested. A GMP vector has been manufactured and is presently in clinical trial.
Haafiz A.B.,University of Florida
Expert Review of Gastroenterology and Hepatology | Year: 2010
Biliary atresia (BA) is the most common cholestatic liver disorder requiring liver transplantation in children. Hepatic fibrosis is not only a universal and prominent feature of BA, it is also the most important predictor of outcome following portoenterostomy (PE). Without PE, the progression of hepatic fibrosis is quite dramatic, such that liver cirrhosis is established within a few weeks after birth. Etiologies and molecular networks underpinning such an expeditious fibrogenic process have not been well established. However, immune and nonimmune factors implicated in the pathogenesis of BA, and the resultant cholestasis and oxidative stress, appear to be the main triggers of hepatic fibrosis in BA. Owing to a lack of validated noninvasive tools to monitor liver fibrosis, current prognostic models of BA entail clinical and biochemical variables reflecting liver dysfunction rather than hepatic fibrogenesis. Further work is necessary to validate the results of preliminary studies indicating a good relationship between liver fibrosis determined by transient elastography and other clinical and routinely performed biochemical parameters in pediatric patients. Although a prime candidate for a number of antifibrotic therapies on the horizon, owing to poor understanding of molecular mechanisms, a clear framework of antifibrotic targets has not been outlined in BA. Similarly, specific antifibrotic therapies have not yet been incorporated in clinical practice, limiting these measures to prompt diagnosis and PE operation, prevention and treatment of cholangitis and optimal nutritional support including the administration of fat-soluble vitamins. © 2010 Expert Reviews Ltd.
Allen-Vercoe E.,University of Guelph |
Jobin C.,University of Florida
Immunology Letters | Year: 2014
The gut microbiota plays an essential role in regulating intestinal homeostasis through its capacity to modulate various biological activities ranging from barrier, immunity and metabolic function. Not surprisingly, microbial dysbiosis is associated with numerous intestinal disorders including inflammatory bowel diseases (IBD) and colorectal cancer (CRC). In this piece, we will review recent evidence that gut microbial dysbiosis can influence intestinal disease, including colitis and CRC. We will discuss the biological events implicated in the development of microbial dysbiosis and the emergence of CRC-associated microorganisms, focusing on Escherichia coli and Fusobacterium nucleatum. Finally, the mechanisms by which E. coli and F. nucleatum exert potentially carcinogenic effects on the host will be reviewed. © 2014 Elsevier B.V..
Boye S.E.,University of Florida
Frontiers in Molecular Neuroscience | Year: 2014
Vertebrate species possess two retinal guanylate cyclases (retGC1 and retGC2) and at least two guanylate cyclase activating proteins (GCAPs), GCAP1 and GCAP2. GCAPs function as Ca2+ sensors that regulate the activity of guanylate cyclases. Together, these proteins regulate cGMP and Ca2+ levels within the outer segments of rod and cone photoreceptors. Mutations in GUCY2D, the gene that encodes retGC1, are a leading cause of the most severe form of early onset retinal dystrophy, Leber congenital amaurosis (LCA1). These mutations, which reduce or abolish the ability of retGC1 to replenish cGMP in photoreceptors, are thought to lead to the biochemical equivalent of chronic light exposure in these cells. In spite of this, the majority of LCA1 patients retain normal photoreceptor laminar architecture aside from foveal cone outer segment abnormalities, suggesting they may be good candidates for gene replacement therapy. Work began in the 1980s to characterize multiple animal models of retGC1 deficiency. 34 years later, all models have been used in proof of concept gene replacement studies toward the goal of developing a therapy to treat GUCY2D-LCA1. Here we use the results of these studies as well as those of recent clinical studies to address specific questions relating to clinical application of a gene therapy for treatment of LCA1. © 2014 Boye.
Alto B.W.,University of Florida |
Bettinardi D.,Urbana University
American Journal of Tropical Medicine and Hygiene | Year: 2013
Temperature is one of the most important environmental factors affecting biological processes of mosquitoes, including their interactions with viruses. In these studies, we show independent effects of rearing temperature on the immature aquatic stages and holding temperature on the adult terrestrial stage in terms of alterations in adult survival and progression of dengue-1 virus infection in the Asian tiger mosquito Aedes (Stegomyia) albopictus. Our studies show that adult survival was determined by adult-holding temperature, regardless of rearing conditions of the immature stages. In contrast, spread of virus throughout the body of the mosquito, a pre-requisite for transmission, was reduced when the immature stages were reared in cool conditions. These results show that immature-rearing temperature selectively modified mosquito traits that influence competency for viruses, and they further our understanding of the nature of temperature effects on interactions between mosquitoes and virus pathogens and risk of disease transmission. Copyright © 2013 by The American Society of Tropical Medicine and Hygiene.
Cardelus C.L.,University of Florida
Biotropica | Year: 2010
The rain forest canopy hosts a large percentage of the world's plant biodiversity, which is maintained, in large part, by internal nutrient cycling. This is the first study to examine the effects of site (canopy, forest floor) and tree species (Dipteryx panamensis, Lecythis ampla, Hyeronima alchorneoides) on decay rates of a common substrate and in situ leaf litter in a tropical forest in Costa Rica. Decay rates were slower for both substrates within the canopy than on the forest floor. The slower rate of mass loss of the common substrate in the canopy was due to differences in microclimate between sites. Canopy litter decay rates were negatively correlated with litter lignin:P ratios, while forest floor decay rates were negatively correlated with lignin concentrations, indicating that the control of litter decay rates in the canopy is P availability while that of the forest floor is carbon quality. The slower cycling rates within the canopy are consistent with lower foliar nutrient concentrations of epiphytes compared with forest floor-rooted plants. Litter decay rates, but not common substrate decay rates, varied among tree species. The lack of variation in common substrate decay among tree species eliminated microclimatic variation as a possible cause for differences in litter decay and points to variation in litter quality, nutrient availability and decomposer community of tree species as the causal factors. The host tree contribution to canopy nutrient cycling via litter quality and inputs may influence the quality and quantity of canopy soil resources. © 2009 The Author(s). Journal compilation © 2010 by The Association for Tropical Biology and Conservation.
Nixon S.J.,University of Florida
Current Opinion in Psychiatry | Year: 2013
Purpose of Review: This article reviews recent findings regarding neurobehavioral factors which may be associated with risk for alcohol misuse, as well as those which may occur as a result of alcohol misuse during adolescence and emerging adulthood. Recent Findings: Current research extends previous findings by engaging multiple assessment methods and integrating behavioral and imaging technologies. These efforts reinforce previous findings regarding alcohol-related changes in macrostructure while demonstrating alterations in brain connectivity previously underappreciated. Longitudinal work now being reported suggests problem use during adolescence may be associated with persistent neurobehavioral aberrations. Summary: For many years, little attention was directed to the neurobehavioral consequences of alcohol use across adolescence and emerging adulthood or to the neurobehavioral factors which might predispose youth to alcohol misuse. Recent work provides critical insights regarding the underpinnings of the deficits in executive function often observed in those at risk for alcohol dependence and those who develop alcohol use disorders. These studies suggest that, even when behavioral deficits are not evident, changes in brain connectivity and microstructure may be observed. Programmatic, longitudinal research must be conducted to determine the relevance of these alterations to use trajectories and long-term adaptation. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Graeber M.B.,University of Sfax |
Graeber M.B.,University of Sydney |
Streit W.J.,University of Florida
Acta Neuropathologica | Year: 2010
The past 20 years have seen a gain in knowledge on microglia biology and microglia functions in disease that exceeds the expectations formulated when the microglia "immune network" was introduced. More than 10,000 articles have been published during this time. Important new research avenues of clinical importance have opened up such as the role of microglia in pain and in brain tumors. New controversies have also emerged such as the question of whether microglia are active or reactive players in neurodegenerative disease conditions, or whether they may be victims themselves. Premature commercial interests may be responsible for some of the confusion that currently surrounds microglia in both the Alzheimer and Parkinson's disease research fields. A critical review of the literature shows that the concept of "(micro)glial inflammation" is still open to interpretation, despite a prevailing slant towards a negative meaning. Perhaps the most exciting foreseeable development concerns research on the role of microglia in synaptic plasticity, which is expected to yield an answer to the question whether microglia are the brain's electricians. This review provides an analysis of the latest developments in the microglia field. © 2009 Springer-Verlag.
Woodard R.P.,University of Florida
International Journal of Modern Physics D | Year: 2014
I argue that cosmological data from the epoch of primordial inflation is catalyzing the maturation of quantum gravity from speculation into a hard science. I explain why quantum gravitational effects from primordial inflation are observable. I then review what has been done, both theoretically and observationally, and what the future holds. I also discuss what this tells us about quantum gravity. © 2014 World Scientific Publishing Company.
Long C.J.,University of Florida
Biofouling | Year: 2010
An algorithm was developed and implemented to map the locations of attached spores of Ulva linza on patterned surfaces. Using this mapping algorithm, spore preference among regions within a pattern can be detected and quantified. Settlement maps of spores on patterned topographies from several assays showed clear preferences in spore settlement. Over 94% of the spores attached within the depressed regions on the surfaces, including a surface containing pits instead of protruding features. The spores attached primarily at the intersections of several features, with over half and up to 96% of spores settling in these regions. The highest spore densities occurred at intersections where the features were most dissimilar. In contrast, the location of attached beads on the surfaces was nearly uniform across the surface. Identification of preferential attachment locations allows for the study of localized properties that influence cell behavior and aids in the development of new surfaces to control cell-surface interactions.
Ramond P.,University of Florida
European Physical Journal C | Year: 2014
Morel L.,University of Florida
Nature Reviews Rheumatology | Year: 2010
Great progress has been made in the field of lupus genetics in the past few years, notably with the publication of genome-wide association studies in humans and the identification of susceptibility genes (including Fcgr2b, Ly108, Kallikrein genes and Coronin-1A) in mouse models of spontaneous lupus. This influx of new information has revealed an ever-increasing interdependence between the mouse and human systems for unraveling the genetic basis of lupus susceptibility. Studies in the 1980s and 1990s established that mice prone to spontaneous lupus constitute excellent models of the genetic architecture of human systemic lupus erythematosus (SLE). This notion has been greatly strengthened by the convergence of the functional pathways that are defective in both human and murine lupus. Within these pathways, variants in a number of genes have now been shown to be directly associated with lupus in both species. Consequently, mouse models will continue to serve a pre-eminent role in lupus genetics research, with an increased emphasis on mechanistic and molecular studies of human susceptibility alleles. © 2010 Macmillan Publishers Limited. All rights reserved.
Powell J.R.,Yale University |
Tabachnick W.J.,University of Florida
Memórias do Instituto Oswaldo Cruz | Year: 2013
The adaptation of insect vectors of human diseases to breed in human habitats (domestication) is one of the most important phenomena in medical entomology. Considerable data are available on the vector mosquito Aedes aegypti in this regard and here we integrate the available information including genetics, behaviour, morphology, ecology and biogeography of the mosquito, with human history. We emphasise the tremendous amount of variation possessed by Ae. aegypti for virtually all traits considered. Typological thinking needs to be abandoned to reach a realistic and comprehensive understanding of this important vector of yellow fever, dengue and Chikungunya.
Lightfoot Y.L.,University of Florida
Gut microbes | Year: 2013
Pathogenic autoinflammatory responses triggered by dysregulated microbial interactions may lead to intestinal disorders and malignancies. Previously, we demonstrated that a lipoteichoic acid (LTA)-deficient Lactobacillus acidophilus strain, NCK2025, ameliorated inflammation-induced colitis, significantly reduced the number of polyps in a colonic polyposis cancer model and restored physiological homeostasis in both cases. Nonetheless, the regulatory signals delivered by NCK2025 to reprogram the gastrointestinal microenvironment, and thus resist colonic cancer progression, remain unknown. Accumulating evidence suggest that epigenetic changes, in the presence and absence of pathogenic inflammation, can result in colorectal cancer (CRC). To test possible epigenetic modifications induced by NCK2025, the expression of epigenetically regulated, CRC-associated genes was measured with and without bacterial treatment. In vivo and in vitro, NCK2025 enhanced the expression of tumor suppressor genes that may regulate CRC development. Therefore, differential epigenetic regulation of CRC-related genes by NCK2025 represents a potential therapy against colitis-associated and sporadic CRC.
Staud R.,University of Florida
Current Rheumatology Reports | Year: 2010
Fibromyalgia syndrome (FM) is a highly prevalent musculoskeletal disorder that is often accompanied by somatic hyperalgesia (enhanced pain from noxious stimuli). Neural mechanisms of somatic hyperalgesia have been analyzed via quantitative sensory testing of FM patients. Results of these studies suggest that FM pain is associated with widespread primary and secondary cutaneous hyperalgesia, which are dynamically maintained by tonic impulse input from deep tissues and likely by brain-to-spinal cord facilitation. Enhanced somatic pains are accompanied by mechanical hyperalgesia and allodynia in FM patients as compared with healthy controls. FM pain is likely to be at least partially maintained by peripheral impulse input from deep tissues. This conclusion is supported by results of several studies showing that injection of local anesthetics into painful muscles normalizes somatic hyperalgesia in FM patients. © 2010 Springer Science+Business Media, LLC.
Jacobson S.K.,University of Florida
American Journal of Primatology | Year: 2010
Conservation education goals generally include influencing people's conservation awareness, attitudes, and behaviors. Effective programs can help foster sustainable behavior, improve public support for conservation, reduce vandalism and poaching in protected areas, improve compliance with conservation regulations, increase recreation carrying capacities, and influence policies and decisions that affect the environment. Primate conservation problems cut across many disciplines, and primate conservation education must likewise address crossdisciplinary issues. Conservation educators must incorporate both theoretical and practical knowledge and skills to develop effective programs, and the skill set must stretch beyond pedagogy. Expertize needed comes from the areas of planning, collaboration, psychology, entertainment, and evaluation. Integration of these elements can lead to greater program success. © 2009 Wiley-Liss, Inc.
Shuster J.J.,University of Florida
Statistics in Medicine | Year: 2010
This article brings into serious question the validity of empirically based weighting in random effects meta-analysis. These methods treat sample sizes as non-random, whereas they need to be part of the random effects analysis. It will be demonstrated that empirical weighting risks substantial bias. Two alternate methods are proposed. The first estimates the arithmetic mean of the population of study effect sizes per the classical model for random effects meta-analysis. We show that anything other than an unweighted mean of study effect sizes will risk serious bias for this targeted parameter. The second method estimates a patient level effect size, something quite different from the first. To prevent inconsistent estimation for this population parameter, the study effect sizes must be weighted in proportion to their total sample sizes for the trial. The two approaches will be presented for a meta-analysis of a nasal decongestant, while at the same time will produce counter-intuitive results for the DerSimonian-Laird approach, the most popular empirically based weighted method. It is concluded that all past publications based on empirically weighted random effects meta-analysis should be revisited to see if the qualitative conclusions hold up under the methods proposed herein. It is also recommended that empirically based weighted random effects meta-analysis not be used in the future, unless strong cautions about the assumptions underlying these analyses are stated, and at a minimum, some form of secondary analysis based on the principles set forth in this article be provided to supplement the primary analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Atkinson M.A.,University of Florida
Cold Spring Harbor perspectives in medicine | Year: 2012
The purpose of this article is to provide an overview that summarizes much in the way of our current state of knowledge regarding the pathogenesis and natural history of type 1 diabetes in humans. This information is presented to the reader as a series of seminal historical discoveries that, when advanced through research, transformed our understanding of the roles for the immune system, genes, and environment in the formation of this disease. In addition, where longitudinal investigations of these three facets occurred, their roles within the development of type 1 diabetes, from birth to symptomatic onset and beyond, are discussed, including their most controversial elements. Having an understanding of this disorder's pathogenesis and natural history is key for attempts seeking to understand the issues of what causes type 1 diabetes, as well as to develop a means to prevent and cure the disorder.
Cassidy R.N.,University of Florida
Journal of the experimental analysis of behavior | Year: 2012
The exponential demand equation proposed by Hursh and Silberberg (2008) provides an estimate of the essential value of a good as a function of price. The model predicts that essential value should remain constant across changes in the magnitude of a reinforcer, but may change as a function of motivational operations. In Experiment 1, rats' demand for food across a sequence of fixed-ratio schedules was assessed during open and closed economy conditions and across one- and two-pellet per reinforcer delivery conditions. The exponential equation was fitted to the relation between fixed-ratio size and the logarithm of the absolute number of reinforcers. Estimates of the rate of change in elasticity of food, the proposed measure of essential value, were compared across conditions. Essential value was equivalent across magnitudes during the closed economy, but showed a slight decrease across magnitudes during the open economy. Experiment 2 explored the behavioral mechanisms of nicotine's effects on consumption with the results from Experiment 1 serving as a within-subject frame of reference. The same subjects were administered nicotine via subcutaneously implanted osmotic minipumps at a dose of 3 mg/kg/day and exposed to both the one- and two-pellet conditions under a closed economy. Although nicotine produced large decreases in demand, essential value was not significantly changed. The data from the present experiments provide further evidence for the adequacy of the exponential demand equation as a tool for quantifying the rate of change in elasticity of a good and for assessing behavioral mechanisms of drug action.
Rowland N.E.,University of Florida
Behavioural Brain Research | Year: 2012
Feeding behavior is described from an evolutionary perspective, and implications for modern neurobiological studies are suggested. In particular, it is argued that meals may have evolved more for sociocultural reasons than physiological imperatives, and that biological approaches to the study of feeding episodes should adopt a more flexible model that is founded in economic or cost-benefit considerations. Specific examples of flexibility in mouse feeding behavior are given. It is further argued that the modern human food environment is so immoderate that physiological manipulations designed to restrain eating have little hope of achieving this goal. © 2011 Elsevier B.V.
Knox G.W.,University of Florida
Aviation Space and Environmental Medicine | Year: 2014
It has been theorized that motion sickness evolved as a negative reinforcement system which terminates motion involving postural instability and/or sensory conflict. A hypothetical example is provided by a "thought experiment" whereby protohominids are in a tree looking for food. Selection pressure results when the organisms that have an aversion to motionproducing sensory conflict do not venture out too far on the tree limbs and therefore tend to survive. In order to support an evolutionary model for motion sickness there must be evidence for genetic and/or heritable predisposition. The present study involves a retrospective literature review which reveals abundant evidence for genetic/heritable factors in motion sickness. Examples include genetic polymorphism of the alpha-2-adrenergic receptor, which has been shown to increase susceptibility to motion sickness, examination of family trees revealing heritable motion sickness susceptibility, evidence indicating that Asians are hyper-susceptible to motion sickness, and twin studies, just to mention a few. Thus, the theory of heritable negative reinforcement as a basis for motion sickness is supported by extensive evidence in the medical literature. This theory is compared and contrasted with other theories. Further areas for research are suggested. © by the Aerospace Medical Association, Alexandria, VA.
Field R.,University of Florida
Annual Review of Nuclear and Particle Science | Year: 2012
I review studies of the underlying event (UE) in hadronic collisions, dating from the first CDF studies in 2000 to the latest LHC findings and surprises. I explain the CDF quantum chromodynamics (QCD) Monte Carlo model tunes and describe how well the Tevatron tunes did at predicting the behavior of the UE at the LHC. In a very short time, the LHC experiments collected a large amount of data at 900 GeV and 7 TeV that can be used to study the UE in great detail. I review the LHC UE results and compare them with one another, with the Tevatron results, and with some of the LHC QCD Monte Carlo model tunes. I also explain the relationship between minimum bias collisions and the UE and discuss new techniques for studying the UE (i.e., techniques beyond the traditional approach). © 2012 by Annual Reviews.
Jadhao C.S.,University of Florida
Investigative ophthalmology & visual science | Year: 2012
In response to ischemia, retinal neuronal cells express nerve growth factor (NGF), which can be proangiogenic. Endothelial progenitor cells (EPCs) can participate with the resident vasculature to promote angiogenesis. We postulated that NGF may stimulate CD34 + EPCs to convert to an angiogenic phenotype. Human CD34 + cells and human retinal endothelial cells (HRECs) were used to examine the effect of NGF on key steps associated with neovascularization. CD34 + cells and HRECs were stimulated with NGF (1 to 4 pM) for 24, 48, and 72 hours. Cell migration was measured using a modified Boyden chamber assay. Expression of the receptor for the cytokine stromal derived growth factor 1 (SDF-1), CXCR-4, was assessed by flow cytometry. In vitro angiogenesis was tested using a three-dimensional (3D) extracellular matrix with HRECs/CD34 + cell cocultures. NGF receptor activation was assessed by western analysis. NGF promoted proliferation of CD34 + cells but not HRECs. Pretreatment of CD34 + cells with NGF increased CXCR-4 expression in CD34 + cells, resulting in enhanced migration to SDF-1 (P < 0.0001). The enhanced tubule-forming effect of NGF in HRECs was further potentiated by coculture with NGF-pretreated CD34 + cells (P < 0.01). The beneficial effect of NGF was blocked (P < 0.0001) by the ERK inhibitor PD98059. In both CD34 + and HRECs, NGF increased phosphorylation of neurotrophic tyrosine kinase receptor type 1 (TrkA) receptor by ERK1 activation (P < 0.01). Our in vitro results suggest that NGF released from ischemic nerves in vivo may contribute to the "angiogenic switch" by stimulating the angiogenic behavior of CD34 + cells while minimally affecting resident retinal endothelial cells.
Jacobson S.G.,University of Pennsylvania |
Cideciyan A.V.,University of Pennsylvania |
Roman A.J.,University of Pennsylvania |
Sumaroka A.,University of Pennsylvania |
And 3 more authors.
New England Journal of Medicine | Year: 2015
Retinal gene therapy for Leber's congenital amaurosis, an autosomal recessive childhood blindness, has been widely considered to be safe and efficacious. Three years after therapy, improvement in vision was maintained, but the rate of loss of photoreceptors in the treated retina was the same as that in the untreated retina. Here we describe long-term follow-up data from three treated patients. Topographic maps of visual sensitivity in treated regions, nearly 6 years after therapy for two of the patients and 4.5 years after therapy for the third patient, indicate progressive diminution of the areas of improved vision. (Funded by the National Eye Institute; ClinicalTrials.gov number, NCT00481546.) Copyright © 2015 Massachusetts Medical Society.
Barbazuk W.B.,University of Florida
RNA Biology | Year: 2010
Uncovering conserved alternative splicing (AS) events can identify AS events that perform important functions. This is especially useful for identifying premature stop codon containing (PTC) AS isoforms that may regulate protein expression by being targets for nonsense mediated decay. This report discusses the identification of a PTC containing splice isoform of the TFIIIA gene that is highly conserved in land plants. TFIIIA is essential for RNA Polymerase III-based transcription of 5S rRNA in eukaryotes. Two independent groups have determined that the PTC containing alternative exon is ultraconserved and is coupled with nonsense-mediated mRNA decay. The alternative exon appears to have been derived by the exonization of 5S ribosomal RNA (5S rRNA) within the gene of its own transcription regulator, TFIIIA. This provides the first evidence of ancient exaptation of 5S rRNA in plants, suggesting a novel gene regulation model mediated by the AS of an anciently exonized non-coding element. © 2010 Landes Bioscience.
Santos J.E.,University of Florida
Society of Reproduction and Fertility supplement | Year: 2010
The establishment and maintenance of pregnancy in lactating dairy cows is a complex biological event that is influenced by a multitude of factors, from the reproductive biology of the cow to managerial aspects of the dairy farm. It is often mentioned in the scientific literature that fertility in dairy cows has declined concurrent with major advances in milk production. Some of this decline is attributed to the negative genetic correlation between milk production and reproduction. In the United States, yearly production per cow has increased steadily at a rate of 1.3% in the last decade and it is likely that this trend will continue in the years to come. At this rate, the average cow in the United States will be producing over 14 tons of milk per year in 2050 and technologies will have to be developed to allow these cows to reproduce to maintain the sustainability of dairy production. Despite high production, it is not uncommon for dairy herds with rolling herd averages for milk yield above 11,000 kg to overcome the challenges of reproduction and obtain satisfactory reproductive performance. Among other things, those herds have been able to mitigate some of the mechanisms that suppress reproduction in dairy cows such as extended postpartum anovulatory period, poor estrous detection, low pregnancy per insemination and, to a lesser extent, the high pregnancy loss. The success of those farms comes from an integrated approach to fertility that includes adequate cow comfort, elaborated transition cow management and nutrition, aggressive postpartum health monitoring program with preventative and curative measures to mitigate the negative effects of diseases on reproduction, and a sound reproductive program that includes manipulation of the ovarian cycle to allow for increased insemination rate. More recently, introduction of fertility traits in selection programs have created new opportunities for improved reproduction without neglecting economically important production traits.
Nair P.K.R.,University of Florida
Journal of Environmental Quality | Year: 2011
Investments in agroforestry research during the past three decades-albeit modest-have yielded significant gains in understanding the role of trees on farmlands, and the ecological and economic advantages of integrated farming systems. While early research focused mostly on farm or local levels, broader-level ecosystem services of agroforestry systems (AFS) have raised high expectations in recent years. The nine papers included in this special collection deal with three of such environmental benefits of AFS: water-quality enhancement, carbon sequestration, and soil improvement. These benefits are based on the perceived ability of (i) vegetative buffer strips (VBS) to reduce surface transport of agrochemical pollutants, (ii) large volumes of aboveground and belowground biomass of trees to store high amounts of C deeper in the soil profile, and (iii) trees to enhance soil productivity through biological nitrogen fixation, efficient nutrient cycling, and deep capture of nutrients. The papers included have, in general, substantiated these premises and provided new insights. For example, the riparian VBS are reported to increase the reservoir life, in addition to reducing transport of agrochemicals; the variations in C storage in different soil-fraction sizes suggest that microaggregate (250-53 μm) dynamics in the soil could be a good indicator of its C-storage potential; and the use of vector analysis technique is recommended in AFS to avoid consequences of inaccurate and overuse of fertilizers. The papers also identified significant knowledge gaps in these areas. A common theme across all three environmental quality issues covered is that more and varied research datasets across a broad spectrum of conditions need to be generated and integrated with powerful statistical tools to ensure wide applicability of the results. Furthermore, appropriate management practices that are acceptable to the targeted land users and agroforestry practitioners need to be designed to exploit these environmental benefits. The relative newness of research in environmental quality of AFS will pose some additional challenges as well. These include the lack of allometric equations for tree-biomass determination, absence of standardized norms on soil sampling depth, and limitations of fixed-effect models arising from issues such as pseudo-replication and repeated measures that are common in studies on preexisting field plots. Overall, this special collection is a timely effort in highlighting the promise of AFS in addressing some of the environmental quality issues, and the challenges in realizing that potential. © 2011 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.
Demkowicz L.,University of Texas at Austin |
Gopalakrishnan J.,University of Florida
Computer Methods in Applied Mechanics and Engineering | Year: 2010
Considering a simple model transport problem, we present a new finite element method. While the new method fits in the class of discontinuous Galerkin (DG) methods, it differs from standard DG and streamline diffusion methods, in that it uses a space of discontinuous trial functions tailored for stability. The new method, unlike the older approaches, yields optimal estimates for the primal variable in both the element size h and polynomial degree p, and outperforms the standard upwind DG method. © 2010 Elsevier B.V.
Kazory A.,University of Florida
Clinical Journal of the American Society of Nephrology | Year: 2013
Heart failure remains the leading cause of hospitalization in older patients and is considered a growing public health problem with a significant financial burden on the health care system. The suboptimal efficacy and safety profile of diuretic-based therapeutic regimens coupled with unsatisfactory results of the studies on novel pharmacologic agents have positioned ultrafiltration on the forefront as an appealing therapeutic option for patients with acute decompensated heart failure (ADHF). In recent years, substantial interest in the use of ultrafiltration has been generated due to the advent of dedicated portable devices and promising results of trials focusing both on mechanistic and clinical aspects of this therapeutic modality. This article briefly reviews the proposed benefits of ultrafiltration therapy in the setting of ADHF and summarizes the major findings of the currently available studies in this field. The results of more recent trials on cardiorenal syndrome that present a counterpoint to previous observations and highlight certain limitations of ultrafiltration therapy are then discussed, followed by identification of major challenges and unanswered questions that could potentially hinder its more widespread use. Future studies are warranted to shed light on less well characterized aspects of ultrafiltration therapy and to further define its role in ADHF and cardiorenal syndrome. © 2013 by the American Society of Nephrology.
Neu J.,University of Florida
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2015
Purpose of review Provide research that relates the developing intestinal microbiome, nutrition, and the subsequent host response to the development of necrotizing enterocolitis (NEC), one of the most common and deadliest diseases seen in newborn infants. After nearly 50 years of little to no progress in this area, we are finally beginning to obtain evidence that is likely to lead to better understanding of both pathophysiology and prevention of the disease. Recent findings We will discuss new discoveries related to the development of the microbiome from prenatal to postnatal life, as well as new findings of microbes and human milk oligosaccharides in human milk as they relate to pathogenesis of NEC. The effect of antibiotics and acid blocking agents, as they may increase the odds of development of NEC, will also be discussed. Summary The implications of these findings are that improved understanding of the developing microbiome, the factors that affect the microbiome including nutrition such as donor milk versus baby's own mother's milk, and certain drugs, will help clinicians to adjust their current feeding and drug utilization to potentially prevent this disease. © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Clark D.J.,Brain Rehabilitation Research Center |
Clark D.J.,University of Florida
Frontiers in Human Neuroscience | Year: 2015
Automaticity is a hallmark feature of walking in adults who are healthy and well-functioning. In the context of walking, “automaticity” refers to the ability of the nervous system to successfully control typical steady state walking with minimal use of attention-demanding executive control resources. Converging lines of evidence indicate that walking deficits and disorders are characterized in part by a shift in the locomotor control strategy from healthy automaticity to compensatory executive control. This is potentially detrimental to walking performance, as an executive control strategy is not optimized for locomotor control. Furthermore, it places excessive demands on a limited pool of executive reserves. The result is compromised ability to perform basic and complex walking tasks and heightened risk for adverse mobility outcomes including falls. Strategies for rehabilitation of automaticity are not well defined, which is due to both a lack of systematic research into the causes of impaired automaticity and to a lack of robust neurophysiological assessments by which to gauge automaticity. These gaps in knowledge are concerning given the serious functional implications of compromised automaticity. Therefore, the objective of this article is to advance the science of automaticity of walking by consolidating evidence and identifying gaps in knowledge regarding: (a) functional significance of automaticity; (b) neurophysiology of automaticity; (c) measurement of automaticity; (d) mechanistic factors that compromise automaticity; and (e) strategies for rehabilitation of automaticity. © 2015 Clark.
Sefah K.,University of Florida
PloS one | Year: 2010
Understanding the molecular features of specific tumors can increase our knowledge about the mechanism(s) underlying disease development and progression. This is particularly significant for colorectal cancer, which is a heterogeneous complex of diseases developed in a sequential manner through a multistep carcinogenic process. As such, it is likely that tumors with similar characteristics might originate in the same manner and have a similar molecular behavior. Therefore, specific mapping of the molecular features can be potentially useful for both tumor classification and the development of appropriate therapeutic regimens. However, this can only be accomplished by developing high-affinity molecular probes with the ability to recognize specific markers associated with different tumors. Aptamers can most easily meet this challenge based on their target diversity, flexible manipulation and ease of development. Using a method known as cell-based Systematic Evolution of Ligands by Exponential enrichment (cell-SELEX) and colorectal cancer cultured cell lines DLD-1 and HCT 116, we selected a panel of target-specific aptamers. Binding studies by flow cytometry and confocal microscopy showed that these aptamers have high affinity and selectivity. Our data further show that these aptamers neither recognize normal colon cells (cultured and fresh), nor do they recognize most other cancer cell lines tested. The selected aptamers can identify specific biomarkers associated with colorectal cancers. We believe that these probes could be further developed for early disease detection, as well as prognostic markers, of colorectal cancers.
Brown K.D.,University of Florida
Breast Cancer Research and Treatment | Year: 2013
Owing to numerous pro-survival target genes, aberrant activation of the NF-κB transcription factor is associated with a drug-resistant phenotype and aggressive breast tumor behavior. Transglutaminase 2 (TG2), a ubiquitously expressed protein cross-linking enzyme, activates NF-κB through a non-conventional mechanism that disables the IκBα inhibitor. Our group has recently documented that the TG2 gene (termed TGM2) is a direct transcriptional target of NF-κB. These developments uncover a novel self-reinforcing molecular feedback loop where TG2 activates NF-κB and, in turn, NF-κB directly upregulates the transcription of TGM2. This manuscript reviews the literature that supports the existence of the TG2/NF-κB signaling loop, the nature of the signal transduction that activates this loop, and the phenotypic consequences stemming from the aberrant activation of this novel signaling mechanism in breast cancer. © 2012 Springer Science+Business Media New York.
Pepine C.J.,University of Florida
Annals of Medicine | Year: 2010
Atherothrombotic disease is highly prevalent in Western countries and is associated with morbidity, mortality, and a significant economic burden. The primary pathophysiological mechanism of acute ischemic events in patients with atherothrombotic disease is complex but involves thrombotic occlusion in response to rupture or erosion of atherosclerotic lesions. Current treatments for long-term secondary prevention in patients with established atherothrombotic disease, such as those with prior myocardial infarction, ischemic stroke/transient ischemic attack, or symptomatic peripheral artery disease, include therapies aimed at preventing rupture/erosion of atherosclerotic lesions (life-style modification and blood pressure reduction, in addition to statins and angiotensin II-active agents) and thrombus formation (primarily antiplatelet agents, such as aspirin, thienopyridines (clopidogrel, prasugrel, ticlopidine), and, to a lesser degree, anticoagulants). Despite the proven benefits and broad use of these therapies, the long-term rates of mortality and recurrent ischemic events remain high. This residual risk can be attributed to the fact that atherothrombosis continues in the presence of current treatments; because these agents each inhibit relatively specific pathways, atherosclerosis, thrombus formation, and other processes may progress. These considerations suggest that novel therapies with a different mechanism of action may provide additional reductions in morbidity and mortality beyond those observed with current agents. © Informa UK Ltd.
Hatch M.,University of Florida
Experimental Physiology | Year: 2014
Studies have shown that compensatory adaptations in gastrointestinal oxalate transport can impact the amount of oxalate excreted by the kidney. Hyperoxaluria is a major risk factor in the formation of kidney stones, and oxalate is derived from both the diet and the liver metabolism of glyoxylate. Although the intestine generally absorbs oxalate from dietary sources and can contribute as much as 50% of urinary oxalate, enteric oxalate elimination plays a significant role when renal function is compromised. While the mechanistic basis for these changes in the direction of intestinal oxalate movements in chronic renal failure involves an upregulation of angiotensin II receptors in the large intestine, enteric secretion/excretion of oxalate can also occur by mechanisms that are independent of angiotensin II. Most notably, the commensal bacterium Oxalobacter sp. interacts with the host enterocyte and promotes the movement of oxalate from the blood into the lumen, resulting in the beneficial effect of significantly lowering urinary oxalate excretion. Changes in the passive permeability of the intestine, such as in steatorrhoea and following gastric bypass, also promote oxalate absorption and hyperoxaluria. In summary, this report highlights the two-way physiological signalling between the gut and the kidney, which may help to alleviate the consequences of certain kidney diseases. © 2014 The Author. Experimental Physiology © 2014 The Physiological Society.
Bourque J.R.,University of Florida
Journal of Vertebrate Paleontology | Year: 2012
The nearly complete skeleton of a mud turtle, Kinosternon skullridgescens, n. sp., is described from Santa Fe County, New Mexico. The specimen was collected from the early middle Miocene, early Barstovian, Skull Ridge Member of the Tesuque Formation (16.0-14.9 Ma) and is one of the oldest and most complete fossil representatives of the genus Kinosternon. Phylogenetically, the new taxon is placed on the stem of the flavescens group in conjunction with the extinct Kinosternon pojoaque from the late Barstovian of New Mexico. In addition to the flavescens group, K. skullridgescens shares morphological similarities with members of the subrubrum group (of North America), as well as with Kinosternon herrerai (from gulf drainages of eastern Mexico). Close proximity of the fossils K. skullridgescens and K. pojoaque to Mexico suggests that a small-plastroned ancestor of the extant taxa K. herrerai, Kinosternon angustipons (from lower Central America), and Kinosternon dunni (from northwestern South America) could have dispersed from North America into Central America by the middle Miocene (Barstovian). Phylogenetic results based on morphology suggest that the taxon Kinosternon steindachneri (formerly Kinosternon subrubrum steindachneri) be reinstated at the species level. © 2012 by the Society of Vertebrate Paleontology.
Duff P.,University of Florida
Obstetrics and Gynecology | Year: 2010
I propose a simple, evidence-based, eight-item checklist that, if followed, should reduce the frequency of many of the most serious complications associated with cesarean delivery: endometritis, wound infection, wound disruption, thrombophlebitis, and uterine scar dehiscence in a subsequent pregnancy. The frequency of abdominal wound infections can be reduced significantly by using electric clippers, rather than a razor, to remove the hair at the site of the surgical incision, washing the skin with a chlorhexidine solution, and administering broad-spectrum antibiotic prophylaxis before the start of surgery rather than after the neonate's umbilical cord has been clamped. Administration of broad-spectrum antibiotic prophylaxis and removal of the placenta by traction on the umbilical cord, rather than by manual extraction, will reduce the frequency of postcesarean endometritis. Closure of the uterine incision in two layers rather than one will significantly reduce the frequency of scar dehiscence in a subsequent pregnancy. Closure of the deep subcutaneous layer in patients whose subcutaneous tissue is greater than 2 cm in thickness will significantly reduce the risk of seroma, hematoma, and subsequent wound disruption. Institution of appropriate prophylaxis for deep vein thrombosis in intermediate and high-risk patients will reduce the risk of subsequent thromboembolic events. © 2010 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins.
Khan S.R.,University of Florida
Urological Research | Year: 2012
Epidemiological studies have provided the evidence for association between nephrolithiasis and a number of cardiovascular diseases including hypertension, diabetes, chronic kidney disease, metabolic syndrome. Many of the co-morbidities may not only lead to stone disease but also be triggered by it. Nephrolithiasis is a risk factor for development of hypertension and have higher prevalence of diabetes mellitus and some hypertensive and diabetic patients are at greater risk for stone formation. An analysis of the association between stone disease and other simultaneously appearing disorders, as well as factors involved in their pathogenesis, may provide an insight into stone formation and improved therapies for stone recurrence and prevention. It is our hypothesis that association between stone formation and development of co-morbidities is a result of certain common pathological features. Review of the recent literature indicates that production of reactive oxygen species (ROS) and development of oxidative stress (OS) may be such a common pathway. OS is a common feature of all cardiovascular diseases (CVD) including hypertension, diabetes mellitus, atherosclerosis and myocardial infarct. There is increasing evidence that ROS are also produced during idiopathic calcium oxalate (CaOx) nephrolithiasis. Both tissue culture and animal model studies demonstrate that ROS are produced during interaction between CaOx/calcium phosphate (CaP) crystals and renal epithelial cells. Clinical studies have also provided evidence for the development of oxidative stress in the kidneys of stone forming patients. Renal disorders which lead to OS appear to be a continuum. Stress produced by one disorder may trigger the other under the right circumstances. © Springer-Verlag 2011.
Sikivie P.,University of Florida
Physical Review Letters | Year: 2014
Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to millikelvin temperatures and count axion induced transitions using laser techniques. This appears to be an appropriate approach to axion dark matter detection in the 10-4eV mass range. © 2014 American Physical Society.
Cao R.,University of Florida |
Yang L.,Colorado State University
IEEE Journal on Selected Areas in Communications | Year: 2012
Forward error correction (FEC) is commonly adopted in cooperative relay communications to ensure link-layer communication reliability. Among those schemes, rateless fountain codes, such as Luby Transform (LT) codes, are favorable for their low complexity and rate adaptability to channel fading dynamics. However, the cooperative transmission schemes based on primitive fountain codes induce either heavy computation cost or large end-to-end latency. To address these issues, we explore decomposed LT (DLT) codes, which comprise of two layers of random encoding but only a single layer of decoding. By implementing the two layers of encoding at the source and the relay(s) respectively, the cooperative system can ensure communication reliability on both source-relay and relay-destination links with reduced computation cost and latency. In this work, we first develop a general decomposition technique for the DLT code construction. Based on this, we further propose a hybrid decomposition algorithm tailored for LT codes with robust Soliton distribution (RSD). The resultant hybrid DLT (h-DLT) codes facilitate flexible computation cost allocation. The h-DLT codes based cooperative relay communication protocol is then developed and analyzed in terms of the transmission latency and energy consumption. © 2006 IEEE.
Kumar A.,University of Florida
Frontiers in Aging Neuroscience | Year: 2011
Synaptic plasticity in the mammalian central nervous system has been the subject of intense investigation for the past four decades. Long-term potentiation (LTP), a major reflection of synaptic plasticity, is an activity-driven long-lasting increase in the efficacy of excitatory synaptic transmission following the delivery of a brief, high-frequency train of electrical stimulation. LTP is regarded as a principal candidate for the cellular mechanisms involved in learning and offers an attractive hypothesis of how memories are constructed. There are a number of exceptional full-length reviews published on LTP; the current review intends to present an overview of the research findings regarding hippocampal LTP with special emphasis on aging, diseases, and psychological insults.
Miller C.W.,University of Florida |
Svensson E.I.,Lund University
Annual Review of Entomology | Year: 2014
Sexual selection has resulted in some of the most captivating features of insects, including flashy colors, bizarre structures, and complex pheromones. These features evolve in dynamic environments, where conditions can change rapidly over space and time. However, only recently has ecological complexity been embraced by theory and practice in sexual selection. We review replicated selection studies as well as studies on variation in the agents of selection to delineate gaps in current knowledge and clarify exciting new directions for research. Existing work suggests that fluctuations in sexual selection may be extremely common, though work on the ecological factors influencing these fluctuations is scarce. We suggest that deeper ecological perspectives on sexual selection may alter some of the fundamental assumptions of sexual selection theory and rapidly lead to new discoveries. © Copyright ©2014 by Annual Reviews. All rights reserved.
Li P.,Mississippi State University |
Fang Y.,University of Florida
IEEE Transactions on Mobile Computing | Year: 2012
A substantial body of the literature exists addressing the capacity of wireless networks. However, it is commonly assumed that all nodes in the network are identical. The issue of heterogeneity has not been embraced into the discussions. In this paper, we investigate the throughput capacity of heterogeneous wireless networks with general network settings. Specifically, we consider an extended network with n normal nodes and m = n b (0 ≤ b ≤ 1) more powerful helping nodes in a rectangular area with width s(n) and length n/s(n), where s(n) = n w and 0 ≤ w ≤ 1/2. We assume that there are n flows in the network. All the n normal nodes are sources while only randomly chosen n d (0 ≤ d ≤ 1) normal nodes are destinations. We further assume that the n normal nodes are uniformly and independently distributed, while the m helping nodes are either regularly placed or uniformly and independently distributed, resulting in two different kinds of networks called Regular Heterogeneous Wireless Networks and Random Heterogeneous Wireless Networks, respectively. We show that network capacity is determined by the shape of the network area, the number of destination nodes, the number of helping nodes, and the bandwidth of helping nodes. We also find that heterogeneous wireless networks can provide throughput higher in the order sense than traditional homogeneous wireless networks only under certain conditions. © 2012 IEEE.
Frost S.C.,University of Florida
Sub-Cellular Biochemistry | Year: 2014
Carbonic anhydrases are ubiquitous enzymes that catalyze the reversible hydration of carbon dioxide. These enzymes are of ancient origin as they are found in the deepest of branches of the evolutionary tree. Of the five different classes of carbonic anhydrases, the alpha class has perhaps received the most attention because of its role in human pathology. This review focuses on the physiological function of this class of carbonic anhydrases organized by their cellular location. © Springer Science+Business Media Dordrecht 2014.
Martyniuk C.J.,University of New Brunswick |
Denslow N.D.,University of Florida
Integrative and Comparative Biology | Year: 2012
In the environment, there are aquatic pollutants that disrupt androgen signaling in fish. Laboratory and field-based experiments have utilized omics technologies to characterize the molecular mechanisms underlying androgen-receptor agonism/antagonism. Transcriptomics and proteomics studies with 17β-trenbolone, a growth-promoting pharmaceutical found in water systems surrounding cattle feed lots, and androgens such as 17α- methyltestosterone and 17α-methyldihydrotestosterone, have been conducted in ovary and liver of fish that include the fathead minnow (FHM) (Pimephales promelas), common carp (Cyprinus carpio), Qurt medaka (Oryzias latipes), and zebrafish (Danio rerio). In this mini-review, we survey recent omics studies in fish and reveal that, despite the diversity of species and tissues examined, there are common cellular responses that are observed with waterborne androgenic treatments. Recurring themes in gene ontology include apoptosis, transport and oxidation of lipids, synthesis and transport of hormones, immune response, protein metabolism, and cell proliferation. However, we also discuss other mechanisms other than androgen receptor (AR) activation, such as responses to toxicant stress, estrogen receptor agonism, aromatization of androgens into estrogens, and inhibitory feedback mechanisms by high levels of androgens that may also explain molecular responses in fish. To further explore androgen-responsive protein networks, a sub-network enrichment analysis was performed on protein data collected from the livers of female FHMs exposed to 17β-trenbolone. We construct a putative AR-regulated protein/cell process network in the liver that includes B-lymphocyte differentiation, xenobiotic clearance, low-density lipoprotein oxidation, proliferation of smooth muscle cells, and permeability of blood vessels. We demonstrate that construction of protein networks can offer insight into cell processes that are potentially regulated by androgens. © 2012 The Author. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved.
Seifert A.W.,University of Kentucky |
Maden M.,University of Florida
International Review of Cell and Molecular Biology | Year: 2014
Regeneration biology has experienced a renaissance as clinicians, scientists, and engineers have combined forces to drive the field of regenerative medicine. Studies investigating the mechanisms that regulate wound healing in adult mammals have led to a good understanding of the stereotypical processes that lead to scarring. Despite comparative studies of fetal wound healing in which no scar is produced, the fact remains that insights from this work have failed to produce therapies that can regenerate adult human skin. In this review, we analyze past and contemporary accounts of wound healing in a variety of vertebrates, namely, fish, amphibians, and mammals, in order to demonstrate how examples of skin regeneration in adult organisms can impact traditional wound-healing research. When considered together, these studies suggest that inflammation and reepithelialization are necessary events preceding both scarring and regeneration. However, the extent to which these processes may direct one outcome over another is likely weaker than currently accepted. In contrast, the extent to which newly deposited extracellular matrix in the wound bed can be remodeled into new skin, and the intrinsic ability of new epidermis to regenerate appendages, appears to underlie the divergence between scar-free healing and the persistence of a scar. We discuss several ideas that may offer areas of overlap between researchers using these different model organisms and which may be of benefit to the ultimate goal of scar-free human wound healing. © 2014 Elsevier Inc.
Israel G.D.,University of Florida
Social Science Computer Review | Year: 2013
This study examines how available e-mail addresses can be incorporated into mixed-mode procedures for surveys of the public, especially client groups. Cooperative Extension Service clients provide the basis for analyzing how implementation procedures affect response rates and substantive findings. These clients form three strata based on contact information provided: postal address only, e-mail only, and both. From clients who provided mail and e-mail addresses, four experimental groups were created, including two mixed-mode groups, a mail-only group and an e-mail-only group. Using mail and e-mail addresses to implement a sequence of e-mail and postal invitations in a mixed-mode design resulted in response rates that are equivalent to those for mail-only surveys. Also, clients who provided a postal address only differed on some attributes from those in the other strata. This study demonstrates the benefit of obtaining e-mail addresses and using them in mixed-mode surveys. © The Author(s) 2012.
Szymczak P.,University of Warsaw |
Ladd A.J.C.,University of Florida
Geophysical Research Letters | Year: 2011
A reactive fluid dissolving the surrounding rock matrix can trigger an instability in the dissolution front, leading to spontaneous formation of pronounced channels or wormholes. Theoretical investigations of this instability have typically focused on a steadily propagating dissolution front that separates regions of high and low porosity. In this paper we show that this is not the only possible dissolutional instability in porous rocks; there is another instability that operates instantaneously on any initial porosity field, including an entirely uniform one. The relative importance of the two mechanisms depends on the ratio of the porosity increase to the initial porosity. We show that the "inlet" instability is likely to be important in limestone formations where the initial porosity is small and there is the possibility of a large increase in permeability. In quartz-rich sandstones, where the proportion of easily soluble material (e.g., carbonate cements) is small, the instability in the steady-state equations is dominant. Copyright 2011 by the American Geophysical Union.
Awad Z.T.,University of Florida
Surgical Endoscopy and Other Interventional Techniques | Year: 2012
Background: Despite the growing acceptance of laparoscopic colon surgery, an abdominal incision is needed to remove the specimen and perform an anastomosis. Methods: Five trocars (one 12 mm and four 5 mm) were used. The video describes the technique of performing laparoscopic subtotal colectomy, laparoscopic cholecystectomy, transrectal removal of the gallbladder and the entire colon, and intracorporeal stapled ileorectal anastomosis in a 27-year-old female with colonic inertia and biliary dyskinesia. Results: There were no intraoperative complications. The operating time was 180 min. Blood loss was 10 cc. The patient was discharged home on postoperative day 4. Conclusion: Laparoscopic subtotal colectomy with transrectal removal of the colon is a safe and effective procedure that can be added to the armamentarium of surgeons performing laparoscopic colon surgery. This technique may provide both an attractive way to reduce abdominal wall morbidity and a bridge to NOTES colon surgery. © 2011 Springer Science+Business Media, LLC.
Ross E.A.,University of Florida
Journal of Cardiac Failure | Year: 2012
Longstanding experimental evidence supports the role of renal venous hypertension in causing kidney dysfunction and "congestive renal failure." A focus has been heart failure, in which the cardiorenal syndrome may partly be due to high venous pressure, rather than traditional mechanisms involving low cardiac output. Analogous diseases are intra-abdominal hypertension and renal vein thrombosis. Proposed pathophysiologic mechanisms include reduced transglomerular pressure, elevated renal interstitial pressure, myogenic and neural reflexes, baroreceptor stimulation, activation of sympathetic nervous and renin angiotensin aldosterone systems, and enhanced proinflammatory pathways. Most clinical trials have addressed the underlying condition rather than venous hypertension per se. Interpreting the effects of therapeutic interventions on renal venous congestion are therefore problematic because of such confounders as changes in left ventricular function, cardiac output, and blood pressure. Nevertheless, there is preliminary evidence from small studies of intense medical therapy or extracorporeal ultrafiltration for heart failure that there can be changes to central venous pressure that correlate inversely with renal function, independently from the cardiac index. Larger more rigorous trials are needed to definitively establish under what circumstances conventional pharmacologic or ultrafiltration goals might best be directed toward central venous pressures rather than left ventricular or cardiac output parameters. © 2012 Elsevier Inc. All rights reserved.
Bona M.,University of Florida
Electronic Journal of Combinatorics | Year: 2012
We prove that the total number S n,132 (q) of copies of the pattern q in all 132-avoiding permutations of length n is the same for q = 231, q = 312, or q = 213. We provide a combinatorial proof for this unexpected threefold symmetry. We then significantly generalize this result by proving a large family of non-trivial equalities of the type S n,132(q) = S n,132(q′).
Mandelbaum A.,Technion - Israel Institute of Technology |
Momcilovic P.,University of Florida
Mathematics of Operations Research | Year: 2012
The asymptotic many-server queue with abandonments, G/GI/N C GI, is considered in the quality- and efficiency-driven (QED) regime. Here the number of servers and the offered load are related via the square-root rule, as the number of servers increases indefinitely. QED performance entails short waiting times and scarce abandonments (high quality) jointly with high servers' utilization (high efficiency), which is feasible when many servers cater to a single queue. For the G/GI/N C GI queue, we derive diffusion approximations for both its queue-length and virtual-waiting-time processes. Special cases, for which closed-form analysis is provided, are the G/M/N CGI and G/D/N CGI queues, thus expanding and generalizing existing results. © 2012 INFORMS.
Atkinson M.A.,University of Florida
Diabetologia | Year: 2014
Over a century ago, inquisitive physicians made remarkable discoveries regarding pancreatic pathology in individuals with diabetes, including those who were likely afflicted with the type 1 (autoimmune) form of the disease. Those studies of post-mortem tissues noted unique anatomical changes in islet architecture as well as the presence of unusual cellular infiltrates. In the time since, investigations of pancreatic pathology have, with near uniformity, been restricted to analysis of organs obtained post-mortem. While clearly beneficial for addressing questions of the disorder's pathogenesis, concern exists regarding potential artefacts that might occur through analysis of tissues that have been recovered hours, often many hours, following death. Beyond this, studies of tissues obtained long after the diagnosis of type 1 diabetes may not disclose important physiological events occurring at onset or even earlier in the natural history of disease, before symptomatic hyperglycaemia. To this end, Krogvold and colleagues (in this issue of Diabetologia, doi: 10.1007/s00125-013-3155-y ) undertook a potentially high-reward strategy involving pancreatic biopsy in living adults with recent-onset type 1 diabetes. Procedures were performed under informed consent, undertaken based on recent improvements in laparoscopic techniques, and carried out by individuals with considerable surgical experience. These efforts were terminated for ethical reasons following the occurrence of serious complications (including post-operative bleeding and pancreatic leakage). The experience lends itself to analogy with the Greek myth of Pandora's box where curiosity, in terms of a desire to see what resided inside a closed container, unleashed a series of ills on humans once the container was opened. In considering the moral of that myth, one must question whether the secrets of the pancreas in those living with type 1 diabetes should, for now, remain a mystery as the process of manipulating that organ for the purpose of curiosity does not occur without harm. © 2014 Springer-Verlag.
Wagh M.S.,University of Florida
American Journal of Gastroenterology | Year: 2014
Management of incidental pancreatic cysts has been a conundrum for the clinician owing to uncertain implications for the presence of cancer or progression to pancreatic malignancy. Asymptomatic pancreatic cysts are being detected in increasing numbers, especially in elderly patients getting radiologic imaging studies for evaluation of other non-pancreatic symptoms and signs. As a result, various radiologic, endoscopic, and pathologic criteria have been developed to help stratify the risk of malignancy in these patients and optimize strategies for patient care including surveillance or resection. In this issue, Wu and co-workers (Am J Gastroenterol, this issue) present their study assessing the prediction of malignancy in cystic neoplasms of the pancreas. © 2014 by the American College of Gastroenterology.
Matyas C.J.,University of Florida
Meteorology and Atmospheric Physics | Year: 2010
This study examines relationships between the extent of hurricane rain fields, storm size, and the environment surrounding the storm. A Geographic Information System is employed to measure the extent of the rain fields in each quadrant of 31 hurricanes at landfall-time. After correlating the extents with measures of storm size, multiple linear regression models are developed to determine which atmospheric forcing(s) at 0, 12, and 24 h prior to landfall are most highly related to rain field size in each quadrant. Results show that the radius of the outermost closed isobar encompasses the rain fields in 90% of the observations. Strong vertical wind shear from the southwest correlates with a larger (smaller) rain field extent toward the northeast (southwest), while higher relative humidity values correlate with a larger extent toward the northwest, southwest, and southeast. Storm and location also exhibit statistically significant correlations with rain field size. © 2010 Springer-Verlag.
Lawrence R.M.,University of Florida
Pediatric Clinics of North America | Year: 2013
This article reviews risks of illness or exposures to breastfed infants. Galactosemia in an infant is a contraindication to breastfeeding. There are no medical conditions in the mother that are contraindications, although diagnostic procedures, treatment, or illness can interfere. Restrictive diets or malnutrition are not contraindications but are opportunities to provide nutritional counseling. Environmental toxic exposures within the United States are uncommon; breastfeeding is not usually contraindicated. In any concerning situation, an assessment and discussion of risks and benefits for the mother-infant dyad (breastfed or formula fed) is indicated. Coordinated medical care and lactation assistance can facilitate successful breastfeeding. © 2013 Elsevier Inc.
Fang X.,CAS Beijing National Laboratory for Molecular |
Tan W.,University of Florida |
Tan W.,Hunan University
Accounts of Chemical Research | Year: 2010
Molecular medicine is an emerging field focused on understanding the molecular basis of diseases and translating this information into strategies for diagnosis and therapy. This approach could lead to personalized medical treatments. Currently, our ability to understand human diseases at the molecular level is limited by the lack of molecular tools to identify and characterize the distinct molecular features of the disease state, especially for diseases such as cancer. Among the new tools being developed by researchers including chemists, engineers, and other scientists is a new class of nucleic acid probes called aptamers, which are ssDNA/RNA molecules selected to target a wide range of molecules and even cells. In this Account, we will focus on the use of aptamers, generated from cell-based selections, as a novel molecular tool for cancer research. Cancers originate from mutations of human genes. These genetic alterations result in molecular changes to diseased cells, which, in turn, lead to changes in cell morphology and physiology. For decades, clinicians have diagnosed cancers primarily based on the morphology of tumor cells or tissues. However, this method does not always give an accurate diagnosis and does not allow clinicians to effectively assess the complex molecular alterations that are predictive of cancer progression. As genomics and proteomics do not yet allow a full access to this molecular knowledge, aptamer probes represent one effective and practical avenue toward this goal. One special feature of aptamers is that we can isolate them by selection against cancer cells without prior knowledge of the number and arrangement of proteins on the cellular surface. These probes can identify molecular differences between normal and tumor cells and can discriminate among tumor cells of different classifications, at different disease stages, or from different patients. This Account summarizes our recent efforts to develop aptamers through cell-SELEX for the study of cancer and apply those aptamers in cancer diagnosis and therapy. We first discuss how we select aptamers against live cancer cells. We then describe uses of these aptamers. Aptamers can serve as agents for molecular profiling of spedfic cancer types. They can also be used to modify therapeutic reagents to develop targeted cancer therapies. Aptamers are also aiding the discovery of new cancer biomarkers through the recognition of membrane protdn targets. Importantly, we demonstrate how molecular assemblies can integrate the properties of aptamers and, for example, nanoparticles or microfluidic devices, to improve cancer cell enrichment, detection and therapy. Figure Presented. © 2010 American Chemical Society.
Hamersma S.,University of Florida |
Kim M.,Thomas University
Journal of Health Economics | Year: 2013
In this paper, we examine the effects of recent parental Medicaid eligibility expansions on Medicaid participation and private insurance coverage. We present a new approach for estimating these policy effects that explicitly models the particular policy instrument over which legislators have control-income eligibility thresholds. Our approach circumvents estimation problems stemming from misclassification or measurement error. Moreover, it allows us to assess how the policy effects may vary at different initial threshold levels. Using data from the Survey of Income and Program Participation, we find three main results. First, the eligibility expansions result in significant increases in Medicaid participation; a " typical" expansion increases Medicaid participation by about four percent of baseline coverage rates. Second, the participation effect is larger for lower initial thresholds and the effect decreases as Medicaid thresholds increase. Third, we find no statistically significant evidence of crowd out regardless of initial threshold level. © 2012 Elsevier B.V.
Hahn D.A.,University of Florida |
Denlinger D.L.,Ohio State University
Annual Review of Entomology | Year: 2011
Managing metabolic resources is critical for insects during diapause when food sources are limited or unavailable. Insects accumulate reserves prior to diapause, and metabolic depression during diapause promotes reserve conservation. Sufficient reserves must be sequestered to both survive the diapause period and enable postdiapause development that may involve metabolically expensive functions such as metamorphosis or long-distance flight. Nutrient utilization during diapause is a dynamic process, and insects appear capable of sensing their energy reserves and using this ormation to regulate whether to enter diapause and how long to remain in diapause. Overwintering insects on a tight energy budget are likely to be especially vulnerable to increased temperatures associated with climate change. Molecular mechanisms involved in diapause nutrient regulation remain poorly known, but insulin signaling is likely a major player. We also discuss other possible candidates for diapause-associated nutrient regulation including adipokinetic hormone, neuropeptide F, the cGMP-kinase For, and AMPK. © 2011 by Annual Reviews. All rights reserved.
Jiang Y.,Qualcomm |
Varanasi M.K.,University of Colorado at Boulder |
Li J.,University of Florida
IEEE Transactions on Information Theory | Year: 2011
This paper presents an in-depth analysis of the zero forcing (ZF) and minimum mean squared error (MMSE) equalizers applied to wireless multiinput multioutput (MIMO) systems with no fewer receive than transmit antennas. In spite of much prior work on this subject, we reveal several new and surprising analytical results in terms of output signal-to-noise ratio (SNR), uncoded error and outage probabilities, diversity-multiplexing (D-M) gain tradeoff and coding gain. Contrary to the common perception that ZF and MMSE are asymptotically equivalent at high SNR, we show that the output SNR of the MMSE equalizer (conditioned on the channel realization) is ρmmse = ρzf+ηsnr, where ρzf is the output SNR of the ZF equalizer and that the gap ηsnr is statistically independent of ρzf and is a nondecreasing function of input SNR. Furthermore, as snr → ∞, ηsnr converges with probability one to a scaled F random variable. It is also shown that at the output of the MMSE equalizer, the interference-to-noise ratio (INR) is tightly upper bounded by ηsnr/ρzf. Using the decomposition of the output SNR of MMSE, we can approximate its uncoded error, as well as outage probabilities through a numerical integral which accurately reflects the respective SNR gains of the MMSE equalizer relative to its ZF counterpart. The ∈-outage capacities of the two equalizers, however, coincide in the asymptotically high SNR regime. We also provide the solution to a long-standing open problem: applying optimal detection ordering does not improve the D-M tradeoff of the vertical Bell Labs layered Space-Time (V-BLAST) architecture. It is shown that optimal ordering yields a SNR gain of 10log10 N dB in the ZF-V-BLAST architecture (where N is the number of transmit antennas) whereas for the MMSE-V-BLAST architecture, the SNR gain due to ordered detection is even better and significantly so. © 2011 IEEE.
Sollenberger L.E.,University of Florida
Crop Science | Year: 2015
Grazing experiments provide fundamental information on the biology of grassland ecosystems, enable selection of persistent forage cultivars that support animal production, and develop management guidelines for end users. Challenges to proper conduct of grazing research include achieving meaningful time and spatial scales, difficulty in measurement of key variables, and scarcity of research funding. Opportunities are emerging for grazing research as a result of increasing awareness of grassland multifunctionality, ecosystem services, and environmental impacts. Capitalizing on these opportunities will require increased participation in grazing research by collaborators from a broader range of ecosystem sciences. This facilitates answering traditional production questions while concurrently discovering new knowledge regarding the larger grassland agroecosystem. Application of grazing research implies adoption by clientele and achieving realworld impacts. Targeting technology and products to specific clientele and achieving on-farm participation by change agents within the target audience can provide highly visible pilot studies that attract users to new technologies. The future of grazing research is not assured, but opportunities are emerging for scientists who engage collaborators representing a broader range of ecosystem sciences and who effectively develop and communicate their program outputs to clientele leading to adoption and measurable impacts. © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved.
Thorn C.B.,University of Florida
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016
We develop the 1/N expansion for stable string bit models, focusing on a model with bit creation operators carrying only transverse spinor indices a=1,...,s. At leading order (N= ∞), this model produces a (discretized) light cone string with a "transverse space" of s Grassmann worldsheet fields. Higher orders in the 1/N expansion are shown to be determined by the overlap of a single large closed chain (discretized string) with two smaller closed chains. In the models studied here, the overlap is not accompanied with operator insertions at the break/join point. Then, the requirement that the discretized overlap has a smooth continuum limit leads to the critical Grassmann "dimension" of s=24. This "protostring," a Grassmann analog of the bosonic string, is unusual, because it has no large transverse dimensions. It is a string moving in one space dimension, and there are neither tachyons nor massless particles. The protostring, derived from our pure spinor string bit model, has 24 Grassmann dimensions, 16 of which could be bosonized to form 8 compactified bosonic dimensions, leaving 8 Grassmann dimensions - the worldsheet content of the superstring. If the transverse space of the protostring could be "decompactified," string bit models might provide an appealing and solid foundation for superstring theory. © 2016 American Physical Society.
Lyakh D.I.,University of Florida
Molecular Physics | Year: 2012
In this (first) paper we attempt to generalize the notion of tensor connectivity, subsequently studying how this property is affected in different tensorial operations. We show that the often implied corollary of the linked diagram theorem, namely individual size-extensivity of arbitrary connected closed diagrams, can be violated in Coulomb systems. In particular, the assumption of the existence of localized Hartree-Fock orbitals is generally incompatible with the individual size-extensivity of connected closed diagrams when the interaction tensor is generated by the true two-body part of the electronic Hamiltonian. Thus, in general, size-extensivity of a many-body method may originate in specific cancellations of super-extensive quantities, breaking the convenient one-to-one correspondence between the connectivity of arbitrary many-body equations and the size-extensivity of the expectation values evaluated by those equations (for example, when certain diagrams are discarded from the method). Nevertheless, assuming that many-body equations are evaluated for a stable many-particle system, it is possible to introduce a workaround, called the ε-approximation, which restores the individual size-extensivity of an arbitrary connected closed diagram, without qualitatively affecting the asymptotic behavior of the computed expectation values. No assumptions concerning the periodicity of the system and its strict electrical neutrality are made. © 2012 Copyright Taylor and Francis Group, LLC.
O'Connell M.R.,University of California at Berkeley |
Oakes B.L.,University of California at Berkeley |
Sternberg S.H.,University of California at Berkeley |
East-Seletsky A.,University of California at Berkeley |
And 5 more authors.
Nature | Year: 2014
The CRISPR-associated protein Cas9 is an RNA-guided DNA endonuclease that uses RNA-DNA complementarity to identify target sites for sequence-specific double-stranded DNA (dsDNA) cleavage. In its native context, Cas9 acts on DNA substrates exclusively because both binding and catalysis require recognition of a short DNA sequence, known as the protospacer adjacent motif (PAM), next to and on the strand opposite the twenty-nucleotide target site in dsDNA. Cas9 has proven to be a versatile tool for genome engineering and gene regulation in a large range of prokaryotic and eukaryotic cell types, and in whole organisms, but it has been thought to be incapable of targeting RNA. Here we show that Cas9 binds with high affinity to single-stranded RNA (ssRNA) targets matching the Cas9-associated guide RNA sequence when the PAM is presented in trans as a separate DNA oligonucleotide. Furthermore, PAM-presenting oligonucleotides (PAMmers) stimulate site-specific endonucleolytic cleavage of ssRNA targets, similar to PAM-mediated stimulation of Cas9-catalysed DNA cleavage. Using specially designed PAMmers, Cas9 can be specifically directed to bind or cut RNA targets while avoiding corresponding DNA sequences, and we demonstrate that this strategy enables the isolation of a specific endogenous messenger RNA from cells. These results reveal a fundamental connection between PAM binding and substrate selection by Cas9, and highlight the utility of Cas9 for programmable transcript recognition without the need for tags. © 2014 Macmillan Publishers Limited. All rights reserved.
Mohr G.S.,Colorado State University |
Lichtenstein D.R.,University of Colorado at Boulder |
Janiszewski C.,University of Florida
Journal of Marketing | Year: 2012
Nutritional labels are mandatory on virtually all packaged food items sold in the United States. The nutritional information on these labels is reported on a "per-serving-size" basis. However, unbeknownst to many consumers, current Food and Drug Administration regulations allow manufacturers some discretion in setting serving sizes-a factor that the authors hypothesize has implications for consumer behavior. For example, adopting a smaller serving size allows marketers to reduce the reported calories, fat, sugar, and carbohydrates in a product serving, which in turn can influence the anticipated consequences of consumption. Three studies show that manipulating the serving size, and thus calories per serving, for equivalent consumption amounts influences the anticipated guilt of consumption, purchase intentions, and choice behavior. However, the results also show that individual difference and context variables, which heighten consumer attention to nutritional information in general, often focus attention on calorie information but not serving size. This leads to the counterintuitive finding that more nutritionally vigilant consumers are more heavily influenced by serving size manipulations. The authors discuss the managerial and public policy implications. © 2012, American Marketing Association.
Joo W.,University of Florida
Neurosurgery | Year: 2012
The carotid cave was first described more than 20 years ago, but its relationships to the dural rings defining the clinoid segment of the internal carotid artery (ICA), the carotid collar, and the adjacent osseous structures need further definition. To further define the microanatomy of the carotid cave and its relationships to the adjacent structures. : The cave and its relationships were examined in cadaveric specimens using 3 to 40× magnification. The cave is an intradural pouch, found in 19 of 20 paraclinoid areas, that extends below the level of the distal dural ring between the wall of the ICA and the dural collar surrounding the ICA. The distal dural ring is tightly adherent to the anterior and lateral walls of the ICA adjacent the anterior clinoid process and optic strut but not on the medial and posterior sides of the artery facing the upper part of the carotid sulcus where the carotid cave is located. The superior hypophyseal artery frequently arises in the cave. The depth and circumferential length of the cave averaged 2.4 mm (range, 1.5-5 mm) and 9.9 mm (range, 4.5-12 mm), respectively. Aneurysms arising at the level of the cave, although appearing on radiological studies to extend below the level of the upper edge of the anterior clinoid, may extend into and may be a source of subarachnoid space. The surgical treatment of aneurysms arising in the cave requires an accurate understanding of the relationships of the cave to the ICA, dural rings, and carotid collar.
Ellis D.Z.,University of Florida
Cellular Physiology and Biochemistry | Year: 2011
Glaucoma afflicts millions of people worldwide and is a major cause of blindness. The risk to develop glaucoma is enhanced by increases in IOP, which result from deranged flow of aqueous humor. Aqueous humor is a fluid located in the front of the eye that gives the eye its buoyancy and supplies nutrients to other eye tissues. Aqueous humor is secreted by a tissue called ciliary processes and exits the eye via two tissues; the trabecular meshwork (TM) and Schlemm's canal. Because the spaces through which the fluid flows get smaller as the TM joins the area of the Schlemm's canal, there is resistance to aqueous humor outflow and this resistance creates IOP. There is a correlation between changes in TM and Schlemm's canal cell volume and rates of aqueous humor outflow; agents that decrease TM and Schlemm's canal cell volume, increase the rate of aqueous humor outflow, thus decreasing IOP. IOP is regulated by guanylate cyclase activators as shown in humans, rabbits and monkeys. There are two distinct groups of guanylate cyclases, membrane guanylate cyclase and soluble guanylate cyclase (sGC); activation of both have been shown to decrease IOP. Members of the membrane guanylate cyclase family of receptors bind to peptide ligands, while the sGC responds to gases (such as NO and CO 2) and compounds (such as YC1, [3-(5'-hydroxymethyl-2'furyl)-1-benzyl indazole), a benzyl indazole derivative, and BAY-58-2667); activation of either results in formation of cyclic GMP (cGMP) and activation of protein kinase G (PKG) and subsequent phosphorylation of target proteins, including the high conductance calcium activated potassium channel (BKca channel). While activators of both membrane guanylate cyclase and sGC have the ability to lower IOP, the IOP lowering effects of sGC are noteworthy because sGC activators can be topically applied to the eye to achieve an effect. We have demonstrated that activators of sGC increase the rate at which aqueous humor exits the eye in a time course that correlates with the time course for sGC-induced decreases in TM and Schlemm's canal cell volume. Additionally, sGC-induced decrease in cell volume is accompanied by both K + and Cl - efflux induced by activation of K + and Cl - channels, including the BKca channel and/or K +Cl - symport. This suggests that parallel K +Cl - efflux, and resultant H 2O efflux result in decreases in cell volume. These observations suggest a functional role for sGC activators, and suggest that the sGC/cGMP/PKG systems are potential therapeutic targets in the treatment of glaucoma. Copyright © 2011 S. Karger AG, Basel.
Weinreb N.J.,University of Florida
Pediatric endocrinology reviews : PER | Year: 2013
For more than 20 years, "enzyme replacement therapy" (ERT) has been the prevalent treatment approach for lysosomal storage disorders (LSDs). Unfortunately, ERT, as currently administered, is ineffective for primary neuronopathic LSDs. For LSDs whose major disease burden is non-neurological, ERT efficacy is limited by uneven tissue distribution and penetration, immunological intolerance, and disturbed intracellular homeostasis associated with persistent mutant enzymes that are not "replaced" by ERT. Many of these limitations might be circumvented by oral, low molecular weight pharmaceuticals that address relevant LSD pathophysiology and distribute widely in steady state concentrations in all cells and body tissues including the CNS. Two oral small molecule drugs (miglustat and cysteamine) are currently approved for clinical use and two (eliglustat and migalastat) are in advanced stage clinical trials. Several others are in early stages of clinical or pre-clinical investigation. This article reviews current knowledge of small molecule treatment for LSDs including approaches such as substrate synthesis inhibition, pharmacological chaperones, and proteostasis modification.
Jian B.,Siemens AG |
Vemuri B.C.,University of Florida
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2011
In this paper, we present a unified framework for the rigid and nonrigid point set registration problem in the presence of significant amounts of noise and outliers. The key idea of this registration framework is to represent the input point sets using Gaussian mixture models. Then, the problem of point set registration is reformulated as the problem of aligning two Gaussian mixtures such that a statistical discrepancy measure between the two corresponding mixtures is minimized. We show that the popular iterative closest point (ICP) method  and several existing point set registration methods , , , , ,  in the field are closely related and can be reinterpreted meaningfully in our general framework. Our instantiation of this general framework is based on the the L2 distance between two Gaussian mixtures, which has the closed-form expression and in turn leads to a computationally efficient registration algorithm. The resulting registration algorithm exhibits inherent statistical robustness, has an intuitive interpretation, and is simple to implement. We also provide theoretical and experimental comparisons with other robust methods for point set registration. © 2011 IEEE.
Kertes D.A.,University of Florida |
van Dulmen M.,Kent State University
Psychoneuroendocrinology | Year: 2012
One challenge in examining stable individual differences in basal activity of the HPA axis is controlling for internally or externally based situational factors that lead to day-to-day variation in ambulatory cortisol. Disturbed basal activity is of particular interest in studies with children, for whom a dysregulated HPA axis may play an etiologic role in emotional or health outcomes. The purpose of this study was to determine whether trait vs. situationally specific sources of variation can be identified at different points of the diurnal cycle in children and if so, whether state and trait components vary according to time of measurement. Early morning and late evening salivary cortisol was collected from 164 children aged 7 to 11 years. Samples were collected 30. min after wakeup and 30. min before bedtime on 3 weekdays. State, trait, and error components of cortisol levels were assessed using a latent state trait model. Possible influences of sampling day and outlier treatment on parameter estimates were examined. The results showed that a latent trait factor superimposed on state residuals and measurement error was identified for both early morning and late evening cortisol. Model fit was excellent and criteria for invariance tests were met. Trait factors accounted for 41% and 57% of the variance in morning and evening cortisol, respectively. These findings suggest cortisol attributed to trait factors can be identified and are of substantial magnitude at both the peak and nadir of the diurnal cycle. Latent state trait modeling is a potentially useful tool in understanding the role of stable individual differences in cortisol levels for development and health. © 2011 Elsevier Ltd.
Zhu H.J.,University of Florida
Pharmacogenetics and genomics | Year: 2012
Human carboxylesterase 1 (hCES1), encoded by the CES1 gene, is the predominant hepatic hydrolase responsible for the metabolism of many therapeutic agents, toxins, and endogenous substances. Genetic variants of CES1 can affect hCES1 function and expression and ultimately influence clinical response to drugs serving as hCES1 substrates. The CES1 gene consists of three isoforms including the functional CES1A1 and CES1A2 genes and the nonfunctional pseudogene CES1A3. Natural variants of these isoforms exert differing impacts on hCES1 function. However, the existing CES1 genotyping methods are incapable of determining whether these variants belong to CES1A1, CES1A2, or CES1A3 because of the high similarity among these three genes, as a consequence they are unable to discriminate between heterozygotes and homozygotes. We report the development of a novel long-range PCR-based, discriminative genotyping assay capable of specifically detecting the variants among CES1A1, CES1A2, and CES1A3 genes. The comparison of the genotyping results between this novel assay and those previously reported methods highlighted the necessity of applying the discriminative genotyping assay in pharmacogenetic studies involving CES1 gene.
Mazzaferri E.L.,University of Florida
Yonsei Medical Journal | Year: 2012
Papillary thyroid microcarcinomas (PTMCs) are the most common form of classic papillary thyroid carcinoma (PTC). PTMCs are typically discovered by fine-needle- aspiration biopsy (FNAB), usually with sensitive imaging studies, or are found during thyroid surgery in a patient without a previously known history of thyroid carcinoma. However, the definition of PTMC has not always been universally accepted, thus creating controversy concerning the diagnosis and treatment of PTMC. The aim of this review is to summarize the clinical features of PTMC and identify the widely differing opinions concerning the diagnosis and management of these small ubiquitous thyroid tumors. © Yonsei University College of Medicine 2012.
Davis T.A.,University of Florida |
ACM Transactions on Mathematical Software | Year: 2011
We describe the University of Florida Sparse Matrix Collection, a large and actively growing set of sparse matrices that arise in real applications. The Collection is widely used by the numerical linear algebra community for the development and performance evaluation of sparse matrix algorithms. It allows for robust and repeatable experiments: robust because performance results with artificially generated matrices can be misleading, and repeatable because matrices are curated and made publicly available in many formats. Its matrices cover a wide spectrum of domains, include those arising from problems with underlying 2D or 3D geometry (as structural engineering, computational fluid dynamics, model reduction, electromagnetics, semiconductor devices, thermodynamics, materials, acoustics, computer graphics/vision, robotics/kinematics, and other discretizations) and those that typically do not have such geometry (optimization, circuit simulation, economic and financial modeling, theoretical and quantum chemistry, chemical process simulation, mathematics and statistics, power networks, and other networks and graphs). We provide software for accessing andmanaging the Collection, from MATLAB™, Mathematica™, Fortran, and C, as well as an online search capability. Graph visualization of the matrices is provided, and a new multilevel coarsening scheme is proposed to facilitate this task. © 2011 ACM 0098-3500/2011/11-ART1.
Lane M.A.,University of Florida
Respiratory Physiology and Neurobiology | Year: 2011
Maintenance of life among higher vertebrates depends on permanent, rhythmic and coordinated activity of respiratory muscles. Fundamental to our understanding of breathing is an appreciation for the neural components involved in the generation, maintenance and modulation of respiratory rhythm. Multidisciplinary studies have revealed important perspectives about the spinal and supraspinal components contributing to breathing, but a complete understanding of respiratory pathways and their interconnectivity remains unknown. Definition of these pathways is essential for understanding how respiratory processes may be affected by injury or disease. The present review highlights our current understanding of the distribution of spinal motoneurons and interneurons involved in mammalian respiratory activity and how they are affected by injury or disease in the central nervous system. © 2011 Elsevier B.V.
Mondello S.,University of Florida
Neurosurgery | Year: 2012
Brain damage markers released in cerebrospinal fluid (CSF) and blood may provide valuable information about diagnosis and outcome prediction after traumatic brain injury (TBI). To examine the concentrations of ubiquitin C-terminal hydrolase-L1 (UCH-L1), a novel brain injury biomarker, in CSF and serum of severe TBI patients and their association with clinical characteristics and outcome. This case-control study enrolled 95 severe TBI subjects (Glasgow Coma Scale [GCS] score, 8). Using sensitive UCH-L1 sandwich ELISA, we studied the temporal profile of CSF and serum UCH-L1 levels over 7 days for severe TBI patients. Comparison of serum and CSF levels of UCH-L1 in TBI patients and control subjects shows a robust and significant elevation of UCH-L1 in the acute phase and over the 7-day study period. Serum and CSF UCH-L1 receiver-operating characteristic curves further confirm strong specificity and selectivity for diagnosing severe TBI vs controls, with area under the curve values in serum and CSF statistically significant at all time points up to 24 hours (P < .001). The first 12-hour levels of both serum and CSF UCH-L1 in patients with GCS score of 3 to 5 were also significantly higher than those with GCS score of 6 to 8. Furthermore, UCH-L1 levels in CSF and serum appear to distinguish severe TBI survivors from nonsurvivors within the study, with nonsurvivors having significantly higher and more persistent levels of serum and CSF UCH-L1. Cumulative serum UCH-L1 levels > 5.22 ng/mL predicted death (odds ratio, 4.8). Serum levels of UCH-L1 appear to have potential clinical utility in diagnosing TBI, including correlating to injury severity and survival outcome.
Morel L.,University of Florida
Advances in Immunology | Year: 2012
Considerable efforts have been deployed over the years to decipher the genetic basis of systemic lupus erythematosus (SLE). The NZM2410 strain is murine model in which the genetic analysis of SLE is the most advanced. NZM2410 studies have shown that, as in SLE patients, lupus susceptibility is achieved by the coexpression of many susceptibility alleles, each of which with a small contribution to the overall disease phenotype. This mouse model has also revealed the critical role played by gene-gene interactions, which are believed to be an essential contribution to human SLE heritability, although it has been much more difficult to characterize. We have now reached a phase in which NZM2410 susceptibility genes have been identified, all them novel in their association with lupus or even with immune functions. Ongoing studies geared at understanding how these genes impact immune tolerance and interact with each other in the mouse, and their impact on the human immune system or target organs, will undoubtedly lead to important discovery for a better understanding on the disease and potential identification of therapeutic targets. © 2012 Elsevier Inc..
Borchelt D.R.,University of Florida
Acta neuropathologica communications | Year: 2014
Greater than 160 missense mutations in copper-zinc superoxide dismutase-1 (SOD1) can cause amyotrophic lateral sclerosis (ALS). These mutations produce conformational changes that reveal novel antibody binding epitopes. A monoclonal antibody, clone C4F6 - raised against the ALS variant G93A of SOD1, has been identified as specifically recognizing a conformation shared by many ALS mutants of SOD1. Attempts to determine whether non-mutant SOD1 adopts a C4F6-reactive conformation in spinal tissues of sporadic ALS (sALS) patients has produced inconsistent results. To define the epitope recognized by C4F6, we tested its binding to a panel of recombinant ALS-SOD1 proteins expressed in cultured cells, producing data to suggest that the C4F6 epitope minimally contains amino acids 90-93, which are normally folded into a tight hairpin loop. Multiple van der Waals interactions between the 90-93 loop and a loop formed by amino acids 37-42, particularly a leucine at position 38, form a stable structure termed the β-plug. Based on published modeling predictions, we suggest that the binding of C4F6 to multiple ALS mutants of SOD1 occurs when the local structure within the β-plug, including the loop at 90-93, is destabilized. In using the antibody to stain tissues from transgenic mice or humans, the specificity of the antibody for ALS mutant SOD1 was influenced by antigen retrieval protocols. Using conditions that showed the best discrimination between normal and misfolded mutant SOD1 in cell and mouse models, we could find no obvious difference in C4F6 reactivity to spinal motor neurons between sALS and controls tissues.
Dukes M.D.,University of Florida
Transactions of the ASABE | Year: 2012
In the past ten years, smart irrigation controllers have been developed by a number of manufacturers and have been promoted by water purveyors in an attempt to reduce excessive irrigation. Legislation has been introduced in California and Texas and passed in Florida mandating or incentivizing the use of these controllers. As a result of the interest in smart controllers, their use is increasing in new installations and retrofits of residential and light commercial irrigation systems. A number of controlled research studies using formal experimental design and statistical analyses indicate substantial water savings of anywhere from 40% to more than 70% when using these devices; however, real-world savings in larger pilot-scale projects indicate savings of typically less than 10%. Reasons for the divergence between the apparent potential savings and the realized savings in pilot projects are related to the lack of: targeting of high irrigation users (on either a relative or absolute scale), education for contractors and end users, and timely follow-up to assess water savings. In addition, much of the scientific research on smart controllers has been conducted in humid regions where higher potential savings are likely due to irrigation needed only to supplement rainfall. Future pilot projects should include comprehensive educational components aimed at irrigation sites with potential irrigation savings based on estimated landscape irrigation demand from climatic variables (i.e., high irrigation users). © 2012 American Society of Agricultural and Biological Engineers.
Leonardo C.C.,University of Florida
Nutritional neuroscience | Year: 2011
Epidemiological studies have demonstrated that the consumption of fruits and vegetables is associated with reduced risk for cardiovascular disease and stroke. Detailed investigations into the specific dietary components of these foods have revealed that many polyphenolic constituents exert anti-oxidant effects on key substrates involved in the pathogenesis and progression of ischemic injury. These data have perpetuated the belief that the protective effects of flavonoids result from direct anti-oxidant actions at the levels of the cerebral vasculature and brain parenchyma. While many in vitro studies using purified extracts support this contention, first-pass metabolism alters the bioavailability of flavonoids such that the achievable concentrations after oral consumption are not consistent with this mechanism. Importantly, oral consumption of flavonoids may promote neural protection by facilitating the expression of gene products responsible for detoxifying the ischemic microenvironment through both anti-oxidative and anti-inflammatory actions. In particular, the transcriptional factor nuclear factor erythroid 2-related factor 2 has emerged as a critical regulator of flavonoid-mediated protection through the induction of various cytoprotective genes. The pleiotropic effects associated with potent transcriptional regulation likely represent the primary mechanisms of neural protection, as the flavonoid concentrations reaching ischemic tissues in vivo are sufficient to alter intracellular signal transduction but likely preclude the one-to-one stoichiometry necessary to confer protection by direct anti-oxidation. These data reflect an exciting new direction in the study of complementary and alternative medicine that may lead to the development of novel therapies for ischemic/hemorrhagic stroke, traumatic brain injury, and other neurological disorders.
Sbicca J.,University of Florida
Agriculture and Human Values | Year: 2012
The food justice movement is a budding social movement premised on ideologies that critique the structural oppression responsible for many injustices throughout the agrifood system. Tensions often arise however when a radical ideology in various versions from multiple previous movements is woven into mobilization efforts by organizations seeking to build the activist base needed to transform the agrifood system. I provide a detailed case study of the People's Grocery, a food justice organization in West Oakland, California, to show how anti-oppression ideology provides the foundation upon which food justice activists mobilize. People's Grocery builds off of previous social justice movements within West Oakland, reflected in activist meaning making around ideas of social justice and autonomy. However, the ongoing mobilization process also faces complications stemming from diverse individual interpretations of food justice-that may not be reflected in the stated goals of food justice organizations-as well as structural constraints. Consequently, building a social movement premised on food justice opens up social spaces for new activism, but may not be a panacea for solving food-related racial and economic inequality. The findings have implications for newly forming food justice organizations, future research on the food justice movement, as well as for theories on social movement mobilization. © 2012 Springer Science+Business Media B.V.
Nair P.K.R.,University of Florida
Agroforestry Systems | Year: 2012
Given the recognized role of agroforestry systems (AFS) in climate change mitigation through carbon sequestration, it is important to have rigorous and consistent procedures to measure the extent of C sequestration. The methods used currently vary widely and the estimations entail several assumptions, some of which are erroneous. Large-scale global models that are based on such measurements and estimations are thus likely to result in serious under- or overestimations. These methodological problems, though common to most land-use systems, are of a higher order of magnitude in AFS compared with agricultural systems because of the integrated nature of AFS and the lack of rigorous data on the area under the practice. While there are no easy, fast, and pragmatic solution to these complex issues in the short term, agroforestry researchers could, at the very minimum, include accurate description of the methods and procedures they use, such as sampling scheme, analytical details, and computational methods, while reporting results. That will help other researchers to examine the datasets and incorporate them in larger databases and help agroforestry earn its deserving place in mainstream efforts. Missing the opportunity to capitalize on the environmental services of agroforestry for the lack of rigorous and consistent procedures for data collection and reporting will be a serious setback to the development of agroforestry. © 2011 Springer Science+Business Media B.V.
Detweiler S.,University of Florida
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012
A point particle of small mass m moves in free fall through a background vacuum spacetime metric gab0 and creates a first-order metric perturbation hab1ret that diverges at the particle. Elementary expressions are known for the singular m/r part of hab1ret and for its tidal distortion determined by the Riemann tensor in a neighborhood of m. Subtracting this singular part hab1S from hab1ret leaves a regular remainder hab1R. The self-force on the particle from its own gravitational field adjusts the world line at O(m) to be a geodesic of gab0+hab1R. The generalization of this description to second-order perturbations is developed and results in a wave equation governing the second-order hab2ret with a source that has an O(m2) contribution from the stress-energy tensor of m added to a term quadratic in hab1ret. Second-order self-force analysis is similar to that at first order: The second-order singular field hab2S subtracted from hab2ret yields the regular remainder hab2R, and the second-order self-force is then revealed as geodesic motion of m in the metric gab0+h1R+h2R. © 2012 American Physical Society.
Feng J.L.,University of California at Irvine |
Matchev K.T.,University of Florida |
Sanford D.,University of California at Irvine
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012
Recent results from Higgs boson and supersymmetry searches at the Large Hadron Collider provide strong new motivations for supersymmetric theories with heavy superpartners. We reconsider focus point supersymmetry (FP SUSY), in which all squarks and sleptons may have multi-TeV masses without introducing fine-tuning in the weak scale with respect to variations in the fundamental SUSY-breaking parameters. We examine both FP SUSY and its familiar special case, the FP region of minimal supergravity, also known as the constrained minimal supersymmetric standard model (mSUGRA/CMSSM), and show that they are beautifully consistent with all particle, astroparticle, and cosmological data, including Higgs boson mass limits, null results from SUSY searches, electric dipole moments, b→sγ, B s→μ +μ -, the thermal relic density of neutralinos, and dark matter searches. The observed deviation of the muon's anomalous magnetic moment from its standard model value may also be explained in FP SUSY, although not in the FP region of mSUGRA/CMSSM. In light of recent data, we advocate refined searches for FP SUSY and related scenarios with heavy squarks and sleptons, and we present a simplified parameter space within mSUGRA/CMSSM to aid such analyses. © 2012 American Physical Society.
Ibrahim S.H.,University of Florida
Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance | Year: 2011
Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging.
Collings P.,University of Florida
Arctic | Year: 2011
This paper examines the social networks of country food sharing in Ulukhaktok, Northwest Territories, Canada, in light of our current understanding of the relationship between climate change and Arctic peoples. Most recent work on the impacts of climate change on Arctic peoples has tended to focus on conceptual frameworks appropriate for this field of inquiry or to document perceived threats of climate change. This research incorporates a social network approach to document the association between different economic strategies (full-time worker, part-time worker, hunter) and categories of kin. It demonstrates that the sharing patterns of hunters favor the cultivation of ties with distant and collateral kin, while those of wage earners favor ties with parents and siblings. These different affiliations point to different vulnerabilities to change. For example, hunters pursue a strategy that provides the flexibility and connections necessary for adapting to changing environmental circumstances but increases their vulnerability to economic and political changes that restrict their ability to generate cash. Wage workers, despite a steady income, are more vulnerable to environmental change as it affects traveling conditions, potential hazards, and hunting success. © The Arctic Institute of North America.
Cheng H.K.,University of Florida |
Liu Y.,University of Scranton
Information Systems Research | Year: 2012
Many software firms offer a fully functional version of their products free of charge, for a limited trial period, to ease consumers' uncertainty about the functionalities of their products and to help the diffusion of their new software. This paper examines the trade-off between the effects of reduced uncertainty and demand cannibalization, uncovers the condition under which software firms should introduce the time-locked free trial software, and finds the optimal free trial time. As software firms have the option of providing free trial software with full functionalities but a limited trial time or limited functionalities for an unlimited trial time, we develop a unified framework to provide useful guidelines for deciding which free trial strategy is preferred in the presence of network externalities and consumer uncertainty. © 2012 INFORMS.
Choe K.P.,University of Florida
American Journal of Physiology - Regulatory Integrative and Comparative Physiology | Year: 2013
Intracellular salt and water homeostasis is essential for all cellular life. Extracellular salt and water homeostasis is also important for multicellular organisms. Many fundamental mechanisms of compensation for osmotic perturbations are well defined and conserved. Alternatively, molecular mechanisms of detecting salt and water imbalances and regulating compensatory responses are generally poorly defined for animals. Throughout the last century, researchers studying vertebrates and vertebrate cells made critical contributions to our understanding of osmoregulation, especially mechanisms of salt and water transport and organic osmolyte accumulation. Researchers have more recently started using invertebrate model organisms with defined genomes and well-established methods of genetic manipulation to begin defining the genes and integrated regulatory networks that respond to osmotic stress. The nematode Caenorhabditis elegans is well suited to these studies. Here, I introduce osmoregulatory mechanisms in this model, discuss experimental advantages and limitations, and review important findings. Key discoveries include defining genetic mechanisms of osmolarity sensing in neurons, identifying protein damage as a sensor and principle determinant of hypertonic stress resistance, and identification of a putative sensor for hypertonic stress associated with the extracellular matrix. Many of these processes and pathways are conserved and, therefore, provide new insights into salt and water homeostasis in other animals, including mammals. © 2013 the American Physiological Society.
Omar S.,Indian Institute of Technology Kanpur |
Nino J.C.,University of Florida
Acta Materialia | Year: 2013
The chemical expansion coefficient of doped ceria has been hitherto assumed to be temperature-independent. In this work, X-ray diffraction techniques are used to determine the effect of doping on the chemical expansion of ceria as a function of temperature in air. At room temperature, it is observed that the chemical expansion in ceria is a combination of two effects: the change in the effective cation radius and the formation of oxygen vacancies. In this study, the chemical expansion coefficient is found to be temperature-dependent, which stands in contrast to previous results that use high-temperature elastic strain data. Specifically, a 22% increase in the chemical expansion coefficient is observed with increasing temperature from room temperature up to 600 °C. This increase is attributed to the dissociation of local defect structures at higher temperatures. The contribution to the increase stemming from oxygen vacancy formation is calculated at various temperatures, and it is assumed that the effective size of anions and cations changes minimally with the temperature changes. More significantly, the effective radius for an oxygen vacancy is seen to be independent of trivalent dopant type and composition. The values determined in this work, as well as the methodology demonstrated, can be used broadly in the prediction of the chemical expansion coefficient at various temperatures for a given doped ceria system. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Neu J.,University of Florida
Clinics in Perinatology | Year: 2014
One of the most controversial areas in neonatology is whether probiotics should be provided routinely to preterm infants to prevent necrotizing enterocolitis (NEC). This review provides the reader with a brief overview of NEC and current concepts of its pathophysiology, discusses the microbial ecology of the intestine in preterm infants and factors that may lead to a "dysbiosis", summarizes studies of probiotics in preterm infants, elaborates on the need for regulation in this area, and discusses alternatives to probiotics and what is the future for the prevention of NEC. © 2014 Elsevier Inc.
Kilina S.,North Dakota State University |
Ramirez J.,University of Florida |
Tretiak S.,Los Alamos National Laboratory
Nano Letters | Year: 2012
Using time-dependent density functional theory, we found that chemical functionalization at low concentrations of single-walled carbon nanotubes (SWNTs) locally alters the π-conjugated network of the nanotube surface and leads to a spatial confinement of the electronically excited wave functions. Depending on the adsorbant positions, the chemisorption significantly modifies the optical selection rules. Our modeling suggests that photoluminescent efficiency of semiconducting SWNT materials can be controlled by selective chemical functionalization. © 2012 American Chemical Society.
Pang J.-J.,University of Florida
Advances in Experimental Medicine and Biology | Year: 2010
Achromatopsia is an autosomal recessive retinal disease involving loss of cone function that afflicts approximately 1 in 30,000 individuals. Patients with achromatopsia usually have visual acuities lower than 20/200 because of the central vision loss, photophobia, complete color blindness and reduced cone-mediated electroretinographic (ERG) amplitudes. Mutations in three genes have been found to be the primary causes of achromatopsia, including CNGB3 (beta subunit of the cone cyclic nucleotide-gated cation channel), CNGA3 (alpha subunit of the cone cyclic nucleotide-gated cation channel), and GNAT2 (cone specific alpha subunit of transducin). Naturally occurring mouse models with mutations in Cnga3 (cpfl5 mice) and Gnat2 (cpfl3 mice) were discovered at The Jackson Laboratory. A natural occurring canine model with CNGB3 mutations has also been found. These animal models have many of the central phenotypic features of the corresponding human diseases. Using adeno-associated virus (AAV)-mediated gene therapy, we and others show that cone function can be restored in all three models. These data suggest that human achromatopsia may be a good candidate for corrective gene therapy. © Springer Science+Business Media, LLC 2010.
Devine D.P.,University of Florida
Methods in Molecular Biology | Year: 2012
Self-injurious behaviour is highly prevalent in neurodevelopmental disorders. Interestingly, it is not restricted to any individual diagnostic group. Rather, it is exhibited in various forms across patient groups with distinct genetic defects and classifications of disorders. This suggests that there may be shared neuropathology that confers vulnerability. Convergent evidence from clinical pharmacotherapy, brain imaging studies, postmortem neurochemical analyses, and animal models indicates that dopaminergic insufficiency is a key culprit. This chapter provides an overview of studies in which animal models have been used to investigate the biochemical basis of self-injury, and highlights the convergence in findings between these models and expression of self-injury in humans. © 2012 Springer Science+Business Media, LLC.
Chambers J.R.,University of Florida
Psychological Science | Year: 2010
People tend to rate members of a positive group (e.g., best friends) as superior to the average of that group and members of a negative group (e.g., worst enemies) as inferior to the average of that group. Five experiments tested a new theoretical account of these nonselective superiority and inferiority biases. According to this account, a member's unique attribute (the dimension distinguishing that member positively or negatively from other group members) is used as the standard for comparing that member with other group members. The experimental results supported this hypothesis. When participants compared a randomly selected popular or unpopular vacation destination with other destinations, the target destination's unique attribute was more accessible than its nonunique attributes (Experiments 1-4), and a popular destination was judged less above average if one of its nonunique attributes was the salient comparison standard (Experiment 4). In addition, the unique attribute was used as the comparison standard for evaluating novel stimuli (Experiment 5). Alternative accounts and implications for general comparison processes are discussed. © The Author(s) 2010.
Masso-Silva J.A.,The New School |
Diamond G.,University of Florida
Pharmaceuticals | Year: 2014
Antimicrobial peptides (AMPs) are found widely distributed through Nature, and participate in the innate host defense of each species. Fish are a great source of these peptides, as they express all of the major classes of AMPs, including defensins, cathelicidins, hepcidins, histone-derived peptides, and a fish-specific class of the cecropin family, called piscidins. As with other species, the fish peptides exhibit broad-spectrum antimicrobial activity, killing both fish and human pathogens. They are also immunomodulatory, and their genes are highly responsive to microbes and innate immuno-stimulatory molecules. Recent research has demonstrated that some of the unique properties of fish peptides, including their ability to act even in very high salt concentrations, make them good potential targets for development as therapeutic antimicrobials. Further, the stimulation of their gene expression by exogenous factors could be useful in preventing pathogenic microbes in aquaculture. © 2014 by the authors; licensee MDPI, Basel, Switzerland.
Beeson Jr. R.C.,University of Florida
HortScience | Year: 2012
Rooted cuttings of Rhaphiolepis indica, a low slow-growing evergreen shrub, were grown outdoors in weighing lysi meters to market size in 11.4-L containers. Actual evapo transpiration (ETA) and evaporation from containers shaded with plastic foliage was determined daily. The first 60 days after transplanting, substrate evaporation accounted for most of ETA and was the major component through the first 127 days. ETA generally followed variations in reference evapo transpiration (ETo). Mean cumulative ETA to produce 90% of measured plants to market size was 101 L or 1.99-m depth per plant based on container surface area. Water need indices, similar to crop coefficients, were highly correlated with percent canopy closure using an exponential decay equation (r2 = 0.898), but a more precise estimate at higher canopy closures was achieved using a third-order inverse polynomial equation (r2 = 0.907). When combined with similar previous data from Viburnum odoratissimum and Ligustrum japonicum, the inverse polynomial equation correlation was 0.802 for all three shrubs. This implies the %Closure model provides a good general base for ETA-based irrigation of woody evergreen shrub species based on canopy size and spacing with improved precision when individual equations are derived by species.
Mooradian A.D.,University of Florida
Drugs and Aging | Year: 2011
Aging is associated with alterations in insulin secretion and action. However, aging per se does not alter the pharmacokinetics of commercially available insulin and its analogues. Insulin therapy in older adults is complicated by psychosocial and physiological changes of aging. Several new insulin and insulin analogue preparations are now available for clinical use. Used as prandial (e.g. insulin lispro, insulin aspart or insulin glulisine) and basal insulin (e.g. insulin glargine, insulin detemir), these analogues simulate physiological insulin profiles more closely than the older conventional insulins.The availability of multiple insulin products provides new opportunities to achieve control of diabetes mellitus. The choice of initial insulin therapy can be made based on blood glucose profiles. Overall, these profiles can be divided into three general patterns that include: (i) round-the-clock hyperglycaemia; (ii) fasting hyperglycaemia with daytime euglycaemia; and (iii) daytime hyperglycaemia with normal fasting blood glucose levels. The prescription of insulin is a dynamic process, and the insulin regimen should be adjusted based on individual response. The goal of diabetes care in older adults is to enhance quality of life without subjecting individuals to complicated treatment regimens that may interfere with their independence in carrying out daily activities. © 2011 Adis Data Information BV. All rights reserved.
Gibbs E.P.,University of Florida
Animal health research reviews / Conference of Research Workers in Animal Diseases | Year: 2010
In the past decade, the pandemics of highly pathogenic avian influenza H5N1 and the novel H1N1 influenza have both illustrated the potential of influenza viruses to rapidly emerge and spread widely in animals and people. Since both of these viruses are zoonotic, these pandemics have been the driving force behind a renewed commitment by the medical and veterinary professions to practice One World, One Health for the control of infectious diseases. The discovery in 2004 that an equine origin H3N8 influenza virus was the cause of an extensive epidemic of respiratory disease in dogs in the USA came as a surprise; at that time dogs were thought to be refractory to infection with influenza viruses. In 2007, a second emerging canine influenza was confirmed in Korea, but this time the causal virus was an H3N2 avian influenza virus. This review focuses on recent events associated with equine and canine influenza viruses. While these viruses do not appear to be zoonotic, the close association between humans and dogs, and to a lesser extent horses, demands that we develop better surveillance and control strategies for emerging diseases in companion animals within the context of One World, One Health.
Golant S.M.,University of Florida
Gerontologist | Year: 2015
An earlier theoretical model equated the construct of residential normalcy with older persons positively appraising their residential environments. Failing to achieve congruent places to live, they initiate assimilative (action) or accommodative (mind) coping strategies. This paper theorizes that the assimilative coping strategies of older persons depend on their secondary appraisal processes whereby they judge the availability, efficaciousness, and viability of their coping options. Older persons with more enriched coping repertoires are theorized as more resilient, making their own decisions, and with access to more resource-rich objectively defined resilient environments. Successful aging formulations infrequently examine how residential environmental adaptations of people influence the quality of their lives. Programmatically, the theory emphasizes the potential of individual and environmental interventions targeting older persons who are not aging successfully. © 2014 The Author.
Parr C.S.,Smithsonian Institution |
Guralnick R.,University of Colorado at Boulder |
Cellinese N.,University of Florida |
Page R.D.M.,University of Glasgow
Trends in Ecology and Evolution | Year: 2012
The accelerating growth of data and knowledge in evolutionary biology is indisputable. Despite this rapid progress, information remains scattered, poorly documented and in formats that impede discovery and integration. A grand challenge is the creation of a linked system of all evolutionary data, information and knowledge organized around Darwin's ever-growing Tree of Life. Such a system, accommodating topological disagreement where necessary, would consolidate taxon names, phenotypic and geographical distributional data across clades, and serve as an integrated community resource. The field of evolutionary informatics, reviewed here for the first time, has matured into a robust discipline that is developing the conceptual, infrastructure and community frameworks for meeting this grand challenge. © 2011 Elsevier Ltd.
De Vries A.,University of Florida
Journal of animal science | Year: 2010
Statistical process control (SPC) is a method of monitoring, controlling, and improving a process through statistical analysis. An important SPC tool is the control chart, which can be used to detect changes in production processes, including animal production systems, with a statistical level of confidence. This paper introduces the philosophy and types of control charts, design and performance issues, and provides a review of control chart applications in animal production systems found in the literature from 1977 to 2009. Primarily Shewhart and cumulative sum control charts have been described in animal production systems, with examples found in poultry, swine, dairy, and beef production systems. Examples include monitoring of growth, disease incidence, water intake, milk production, and reproductive performance. Most applications describe charting outcome variables, but more examples of control charts applied to input variables are needed, such as compliance to protocols, feeding practice, diet composition, and environmental factors. Common challenges for applications in animal production systems are the identification of the best statistical model for the common cause variability, grouping of data, selection of type of control chart, the cost of false alarms and lack of signals, and difficulty identifying the special causes when a change is signaled. Nevertheless, carefully constructed control charts are powerful methods to monitor animal production systems. Control charts might also supplement randomized controlled trials.
Azari H.,University of Florida
Journal of visualized experiments : JoVE | Year: 2011
Stem-like cells have been isolated in tumors such as breast, lung, colon, prostate and brain. A critical issue in all these tumors, especially in glioblastoma mutliforme (GBM), is to identify and isolate tumor initiating cell population(s) to investigate their role in tumor formation, progression, and recurrence. Understanding tumor initiating cell populations will provide clues to finding effective therapeutic approaches for these tumors. The neurosphere assay (NSA) due to its simplicity and reproducibility has been used as the method of choice for isolation and propagation of many of this tumor cells. This protocol demonstrates the neurosphere culture method to isolate and expand stem-like cells in surgically resected human GBM tumor tissue. The procedures include an initial chemical digestion and mechanical dissociation of tumor tissue, and subsequently plating the resulting single cell suspension in NSA culture. After 7-10 days, primary neurospheres of 150-200 μm in diameter can be observed and are ready for further passaging and expansion.
Yam A.,University of Florida
Journal of aging and health | Year: 2013
To examine basic and everyday cognitive predictors of older adults' self-reported instrumental activities of daily living (IADL). Basic and everyday cognitive predictors of self-reported IADL were examined in a sample of healthy, community-dwelling older adults (n = 698) assessed over 5 years of measurement. Multilevel longitudinal analyses revealed linear and quadratic change trends for self-reported IADL function, with steeper declines at higher ages. Within-person, when participants exhibited lower cognitive performance, they also reported more IADL impairment. Everyday cognition remained a significant unique predictor of self-reported IADL after controlling for attrition, resampling effects, temporal gradients, and baseline levels and changes in demographic, sensory, functional, and basic cognitive measures. By itself, everyday cognition appears to be an important predictor of self-reported IADL, and maintains a unique predictive contribution after many covariates are controlled. Future research should consider the inclusion of everyday cognitive measures in functional assessment batteries.
Cutler A.J.,University of Florida
CNS spectrums | Year: 2013
Long-term use of the atypical antipsychotic iloperidone has not been investigated at doses above 16 mg/d. This article describes safety and tolerability results from the 25-week open-label extension of a 4-week placebo- and ziprasidone-controlled clinical trial of iloperidone. Patients received a dose of 24 mg/d (given as 12 mg twice daily; mean dose = 21.6 mg) that could be reduced to 12 mg/d (given once daily at bedtime) any time after day 35 at the investigator's discretion. A total of 72/173 patients (41.6%) completed the open-label extension. Treatment-emergent adverse events (TEAEs), most mild to moderate in severity, included headache (13.9%), weight increase (9.2%), dizziness (6.9%), nausea (6.4%), sedation (6.4%), and insomnia (5.2%). The only notable dose-related TEAEs were increased weight and headache. Levels of serum glucose, lipids, and prolactin were essentially unchanged or decreased during treatment. In general, akathisia and extrapyramidal symptoms (EPS) improved or were unchanged during treatment. There was no signal of worsening of efficacy based on changes from baseline in the Positive and Negative Syndrome Scale-Total. This study further supports the long-term safety and tolerability of iloperidone for the treatment of schizophrenia, including iloperidone's favorable effect on metabolic laboratory parameters and low propensity to cause akathisia or EPS.
Stellefson M.,University of Florida
Journal of medical Internet research | Year: 2011
eHealth literacy refers to the ability of individuals to seek, find, understand, and appraise health information from electronic resources and apply such knowledge to addressing or solving a health problem. While the current generation of college students has access to a multitude of health information on the Internet, access alone does not ensure that students are skilled at conducting Internet searches for health information. Ensuring that college students have the knowledge and skills necessary to conduct advanced eHealth searches is an important responsibility particularly for the medical education community. It is unclear if college students, especially those in the medical and health professions, need customized eHealth literacy training for finding, interpreting, and evaluating health- and medical-related information available on the Internet. The objective of our review was to summarize and critically evaluate the evidence from existing research on eHealth literacy levels among college students between the ages of 17 and 26 years attending various 4-year colleges and universities located around the world. We conducted a systematic literature review on numerous scholarly databases using various combinations of relevant search terms and Boolean operators. The records were screened and assessed for inclusion in the review based on preestablished criteria. Findings from each study that met inclusion criteria were synthesized and summarized into emergent themes. In the final review we analyzed 6 peer-reviewed articles and 1 doctoral dissertation that satisfied the inclusion criteria. The number of participants in each reviewed study varied widely (from 34 to 5030). The representativeness of the results from smaller studies is questionable. All studies measured knowledge and/or behaviors related to college student ability to locate, use, and evaluate eHealth information. These studies indicated that many college students lack eHealth literacy skills, suggesting that there is significant room for improvement in college students' ability to obtain and evaluate eHealth information. Although college students are highly connected to, and feel comfortable with, using the Internet to find health information, their eHealth literacy skills are generally sub par. College students, especially in the health and medical professions, would be well served to receive more customized college-level instruction that improves general eHealth literacy.
Golde T.E.,University of Florida
Alzheimer's Research and Therapy | Year: 2014
Abstract. Perhaps more definitively than any other class of novel Alzheimer's disease (AD) therapy, pre-clinical studies in mouse models of amyloid β (Aβ) deposition have established the disease-modifying potential of anti-Aβ immunotherapy. Despite disappointing results to date from anti-Aβ immunotherapy therapeutic trials, there is continued hope that such immunotherapies, especially if used in the preclinical stages, could prove to be the first disease-modifying therapies available for AD. The general optimism that Aβ-targeting and emerging tau-targeting immunotherapies may prove to be disease modifying is tempered by many unanswered questions regarding these therapeutic approaches, including but not limited to i) lack of precise understanding of mechanisms of action, ii) the factors that regulate antibody exposure in the brain, iii) the optimal target epitope, and iv) the mechanisms underlying side effects. In this review I discuss how answering these and other questions could increase the likelihood of therapeutic success. As passive immunotherapies are also likely to be extremely expensive, I also raise questions relating to cost-benefit of biologic-based therapies for AD that could limit future impact of these therapies by limiting access due to economic constraints. © 2014 BioMed Central Ltd.
Evans D.H.,University of Florida
Acta physiologica (Oxford, England) | Year: 2011
August Krogh proposed that freshwater fishes (and other freshwater animals) maintain body NaCl homoeostasis by extracting these ions from the environment via separate Na(+) /NH(4)(+) and Cl(-) /HCO(3)(-) exchangers in the gill epithelium. Subsequent data from other laboratories suggested that Na(+) uptake was more probably coupled to H(+) secretion via a vesicular proton pump (V-ATPase) electrically coupled to a Na(+) channel. However, despite uncertainty about electrochemical gradients, evidence has accrued that epithelial Na(+) /H(+) exchange indeed may be an alternative pathway for Na(+) uptake. The specific pathways for Na(+) uptake may be species and environment specific. An apical Cl(-) /HCO(3)(-) exchanger is generally accepted for most species (some species do not extract Cl(-) from freshwater), but the relative roles of anion exchanger-like (SLC4A1) vs. pendrin-like (SLC26Z4) exchangers are unknown, and also may be species specific. Most recently, data have supported the presence of an apical Na(+) + Cl(-) cotransporter (NCC-type), despite thermodynamic uncertainty. Ammonia extrusion may be via NH(3) diffusing through the paracellular junctions or NH(4) (+) substitution on both basolateral and apical ionic exchangers (Na(+) + K(+) -ATPase; Na(+) + K(+) + Cl(-) - cotransporter; and Na(+) /H(+) exchanger), but recent evidence suggests that Rhesus-glycoproteins mediate both basolateral and apical movement of ammonia. © 2010 The Author. Acta Physiologica © 2010 Scandinavian Physiological Society.
Dark M.J.,University of Florida
Infection and Drug Resistance | Year: 2013
Over the last ten years, genome sequencing capabilities have expanded exponentially. There have been tremendous advances in sequencing technology, DNA sample preparation, genome assembly, and data analysis. This has led to advances in a number of facets of bacterial genomics, including metagenomics, clinical medicine, bacterial archaeology, and bacterial evolution. This review examines the strengths and weaknesses of techniques in bacterial genome sequencing, upcoming technologies, and assembly techniques, as well as highlighting recent studies that highlight new applications for bacterial genomics. © 2013 Dark.
Latham K.,University of Michigan |
Peek C.W.,University of Florida
Journals of Gerontology - Series B Psychological Sciences and Social Sciences | Year: 2013
Objectives. Although self-rated health (SRH) is recognized as a strong and consistent predictor of mortality and functional health decline, there are relatively few studies examining SRH as a predictor of morbidity. This study examines the capacity of SRH to predict the onset of chronic disease among the late midlife population (ages 51-61 years).Method. Utilizing the first 9 waves (1992-2008) of the Health and Retirement Study, event history analysis was used to estimate the effect of SRH on incidence of 6 major chronic diseases (coronary heart disease, diabetes, stroke, lung disease, arthritis, and cancer) among those who reported none of these conditions at baseline (N = 4,770).Results. SRH was a significant predictor of onset of any chronic condition and all specific chronic conditions excluding cancer. The effect was particularly pronounced for stroke.Discussion. This research provides the strongest and most comprehensive evidence to date of the relationship between SRH and incident morbidity. © 2012 The Author. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved.
Harper S.J.,University of Florida
Frontiers in Microbiology | Year: 2013
Amongst the Closteroviridae, Citrus tristeza virus (CTV) is almost unique in possessing a number of distinct and characterized strains, isolates of which produce a wide range of phenotype combinations among its different hosts. There is little understanding to connect genotypes to phenotypes, and to complicate matters more, these genotypes are found throughout the world as members of mixed populations within a single host plant. There is essentially no understanding of how combinations of genotypes affect symptom expression and disease severity. We know little about the evolution of the genotypes that have been characterized to date, little about the biological role of their diversity and particularly, about the effects of recombination. Additionally, genotype grouping has not been standardized. In this study we utilized an extensive array of CTV genomic information to classify the major genotypes, and to determine the major evolutionary processes that led to their formation and subsequent retention. Our analyses suggest that three major processes act on these genotypes: (1) ancestral diversification of the major CTV lineages, followed by (2) conservation and co-evolution of the major functional domains within, though not between CTV genotypes, and (3) extensive recombination between lineages that have given rise to new genotypes that have subsequently been retained within the global population. The effects of genotype diversity and host-interaction are discussed, as is a proposal for standardizing the classification of existing and novel CTV genotypes. © 2013 Harper.
Fu H.,Fudan University |
Tsang S.-W.,University of Florida
Nanoscale | Year: 2012
Simple solution phase, catalyst-free synthetic approaches that offer monodispersed, well passivated, and non-aggregated colloidal semiconductor nanocrystals have presented many research opportunities not only for fundamental science but also for technological applications. The ability to tune the electrical and optical properties of semiconductor nanocrystals by manipulating the size and shape of the crystals during the colloidal synthesis provides potential benefits to a variety of applications including photovoltaic devices, light-emitting diodes, field effect transistors, biological imaging/labeling, and more. Recent advances in the synthesis and characterization of colloidal lead chalcogenide nanocrystals and the achievements in colloidal PbS or PbSe nanocrystals solar cells have demonstrated the promising application of infrared-emitting colloidal lead chalcogenide nanocrystals in photovoltaic devices. Here, we review recent progress in the synthesis and optical properties of colloidal lead chalcogenide nanocrystals. We focus in particular upon the size- and shape-controlled synthesis of PbS, PbSe, and PbTe nanocrystals by using different precursors and various stabilizing surfactants for the growth of the colloidal nanocrystals. We also summarize recent advancements in the field of colloidal nanocrystals solar cells based on colloidal PbS and PbSe nanocrystals. © 2012 The Royal Society of Chemistry.
Ptitsyn A.,University of Florida
BMC bioinformatics | Year: 2012
Early evolution of animals led to profound changes in body plan organization, symmetry and the rise of tissue complexity including formation of muscular and nervous systems. This process was associated with massive restructuring of animal genomes as well as deletion, acquisition and rapid differentiation of genes from a common metazoan ancestor. Here, we present a simple but efficient workflow for elucidation of gene gain and gene loss within major branches of the animal kingdom. We have designed a pipeline of sequence comparison, clustering and functional annotation using 12 major phyla as illustrative examples. Specifically, for the input we used sets of ab initio predicted gene models from the genomes of six bilaterians, three basal metazoans (Cnidaria, Placozoa, Porifera), two unicellular eukaryotes (Monosiga and Capsospora) and the green plant Arabidopsis as an out-group. Due to the large amounts of data the software required a high-performance Linux cluster. The final results can be imported into standard spreadsheet analysis software and queried for the numbers and specific sets of genes absent in specific genomes, uniquely present or shared among different taxons. The developed software is open source and available free of charge on Open Source principles. It allows the user to address a number of specific questions regarding gene gain and gene loss in particular genomes, and user-defined groups of genomes can be formulated in a type of logical expression. For example, our analysis of 12 sequenced genomes indicated that these genomes possess at least 90,000 unique genes and gene families, suggesting enormous diversity of the genome repertoire in the animal kingdom. Approximately 9% of these gene families are shared universally (homologous) among all genomes, 53% are unique to specific taxa, and the rest are shared between two or more distantly related genomes.
Kumar A.,University of Florida
Journal of Neurophysiology | Year: 2010
Dysregulation of the cholinergic transmitter system is a hallmark of Alzheimer's disease and contributes to an age-associated decline in memory performance. The current study examined the influence of carbachol, a cholinergic receptor agonist, on synaptic transmission over the course of aging. Extracellular excitatory postsynaptic field potentials were recorded from CA3-CA1 synapses in acute hippocampal slices obtained from young adult (5-8 mo) and aged (22-24 mo) male Fischer 344 rats. Bath application of carbachol elicited a transient depression of synaptic transmission, which was followed by a long-lasting depression (CCh-LTD) observed 90 min after carbachol cessation in both age groups. However, the magnitude of CCh-LTD was significantly larger in senescent animals and was attenuated by N-methyl-D-aspartate receptor blockade in aged animals. Blockade of L-type Ca 2+ channels inhibited CCh-LTD to a greater extent in aged animals compared to young adults. Finally, the expression of CCh-LTD was dependent on protein synthesis. The results indicate that altered Ca 2+ homeostasis or muscarinic activation of Ca 2+ signaling contribute to the enhanced CCh-LTD during senescence. Copyright © 2010 The American Physiological Society.
McLamore E.S.,University of Florida |
Porterfield D.M.,Purdue University
Chemical Society Reviews | Year: 2011
Biophysical phenomena related to cellular biochemistry and transport are spatially and temporally dynamic, and are directly involved in the regulation of physiology at the sub-cellular to tissue spatial scale. Real time monitoring of transmembrane transport provides information about the physiology and viability of cells, tissues, and organisms. Combining information learned from real time transport studies with genomics and proteomics allows us to better understand the functional and mechanistic aspects of cellular and sub-cellular systems. To accomplish this, ultrasensitive sensing technologies are required to probe this functional realm of biological systems with high temporal and spatial resolution. In addition to ongoing research aimed at developing new and enhanced sensors (e.g., increased sensitivity, enhanced analyte selectivity, reduced response time, and novel microfabrication approaches), work over the last few decades has advanced sensor utility through new sensing modalities that extend and enhance the data recorded by sensors. A microsensor technique based on phase sensitive detection of real time biophysical transport is reviewed here. The self-referencing technique converts non-invasive extracellular concentration sensors into dynamic flux sensors for measuring transport from the membrane to the tissue scale. In this tutorial review, we discuss the use of self-referencing micro/nanosensors for measuring physiological activity of living cells/tissues in agricultural, environmental, and biomedical applications comprehensible to any scientist/engineer. © 2011 The Royal Society of Chemistry.
Kapur S.K.,University of Wisconsin - Madison |
Katz A.J.,University of Florida
Biochimie | Year: 2013
Recent advances in protein detection and analysis have lead to multiple in depth studies that analyze the adipose-derived stem cell (ASC) secretome. These studies differ significantly in their methods of secretome preparation and analysis. Most of them use a pro-differentiation or pro-inflammatory stimulus to observe differential expression of secreted proteins. In spite of the variance in methodologies used, 68 proteins are reported to be commonly expressed in a majority of the studies and may serve as potential candidates for conserved secretome proteins. Multiple recent clinical and basic science studies demonstrate the beneficial role played by secreted proteins in augmenting ASC effects in scenarios involving angiogenesis, wound healing, tissue regeneration and immunomodulation. Furthermore, 3-D formulations of ASCs that preserve the niche environment of cells and their secreted proteins have also shown enhanced clinical effects. In light of the lack of uniformity in prior secretome-analysis studies, and the growing clinical importance of the ASC secretome, more in depth studies that use uniform and standardized means of protein detection and analysis are necessary. © 2013 Elsevier Masson SAS. All rights reserved.
Kumar S.,University of Florida
Internet and Higher Education | Year: 2014
This article describes the signature pedagogy, design, research, and redesign of the first to third iterations of an online doctoral program for educational technology leaders. The development of the online program over four years, based on mixed methods used in each iteration is presented with a focus on online teaching and learning, community-building, and transformational learning. The deep and implicit structure of signature pedagogy in the program endured but the surface structure changed based on feedback from students and faculty. Lessons learned and implications for designing online doctoral degrees and research in online programs are discussed. © 2013 Elsevier Inc.
Kazory A.,University of Florida |
Elkayam U.,University of Southern California
Journal of Cardiac Failure | Year: 2014
Simultaneous dysfunction of the heart and the kidney represents a distinct spectrum of disease states composed of complex clinical scenarios with adverse outcomes. Worsening renal function (WRF) in the setting of acute decompensated heart failure (ADHF) is one such clinical setup for which the underlying mechanisms are poorly understood. Apparent discrepancies exist between the emerging data on the cardiorenal interactions of patients with ADHF and contemporary concepts such as the low forward flow or the high backward pressure hypotheses. The findings of recent retrospective studies also suggest that apparent "improvement in renal function" might be yet another risk factor for untoward outcomes in this patient population, further challenging our current understanding of the cardiorenal interactions. Besides, these data do not seem to fully support our conventional thinking about other aspects of these interactions such as the independent adverse impact of WRF on the outcomes of patients with ADHF, pointing to congestion as a possibly overlooked factor. In this article, we provide an overview of these emerging controversial issues with the goal of identifying the areas where clinical research could be most helpful, because it is of paramount importance to characterize the pathways leading to WRF in ADHF to develop a mechanistically relevant management strategy. Although the paucity of data coupled with the complexity of this field precludes any firm conclusion, these discussions are meant to prompt clinicians and researchers to revisit a number of long-believed concepts surrounding the cardiorenal interactions in ADHF. © 2014 Elsevier Inc. All rights reserved.
Hansen P.J.,University of Florida
Reproduction in Domestic Animals | Year: 2011
Contents: The mammalian conceptus undergoes development in the face of a functional immune system. This characteristic of viviparity creates opportunities and perils for the conceptus. In the period up to hatching from the zona pellucida, the conceptus appears immunologically inert with low expression of major histocompatibility complex (MHC) genes and little evidence for alterations in the function of maternal immune cells. The conceptus may benefit from cytokines produced by leucocytes resident in the reproductive tract or by other cells of the reproductive tract. One cytokine in particular, colony-stimulating factor 2, can promote preimplantation development and cause changes in conceptus function that increase the likelihood that the conceptus develops to term. It is not clear whether activation of specific types of immune responses in early pregnancy can enhance the likelihood of pregnancy success. Semen deposition causes inflammation in the reproductive tract, but there is little evidence that this process is beneficial to pregnancy unless the uterus was exposed to a prior inflammatory event. Around the time of placentation, the period of immunological inertness of the conceptus is replaced by a period of immune activation caused by the expression of interferon genes in ruminants and pigs and MHC class I genes in invasive trophoblast of the horse. The large-scale changes in the endometrium that occur as a result are likely to play an important role to ensure continued development of the conceptus. In contrast, other immune responses generated as a result of disease in the reproductive tract or other tissues (mastitis) can lead to death of the conceptus. Because of this hazard, as well as the possibility that cell-mediated immune responses against the conceptus could occur, the immune system is regulated by both the mother and conceptus to reduce immune responsiveness during pregnancy. © 2011 Blackwell Verlag GmbH.
Channell J.E.T.,University of Florida |
Lanci L.,Urbino University
Earth and Planetary Science Letters | Year: 2014
Late Oligocene to Early Miocene relative paleointensity (RPI) proxies can be correlated from the equatorial Pacific (IODP Site U1334 and ODP Site 1218) to the South Atlantic (ODP Site 1090). Age models are constrained by magnetic polarity stratigraphy through correlation to a common geomagnetic polarity timescale. The RPI records do not contain significant power at specific (orbital) frequencies, and hence there is no significant coherency between RPI proxies and the normalizers used to construct the proxies, although orbital power is present in some normalizers. There is no obvious control on RPI proxies from mean sedimentation rate within polarity chrons, magnetic grain size proxies or magnetic concentration parameters. The salient test is whether the equatorial Pacific records can be correlated one to another, and to the records from the South Atlantic. All records are dominated by RPI minima at polarity reversals, as expected, although the comparison within polarity chrons is compelling enough to conclude that the intensity of the Earth's axial dipole is being recorded. This is supported by the fit of RPI data from Sites U1334 and 1218 after correlation of the two sites using diverse core-scanning data, rather than polarity reversals alone. We do not see a consistent relationship between polarity-chron duration and mean RPI, and no consistent skewness ("saw-tooth" pattern) for RPI within polarity chrons. Stacks of RPI records for 17.5-26.5 Ma include long-term changes in RPI on Myr timescales that are superimposed on RPI minima associated with polarity reversals, and shorter-term variations in RPI with an apparent pacing of ~50 kyr. The equatorial Pacific to South Atlantic correlations indicate that RPI can be used as a (global) stratigraphic tool in pre-Quaternary sediments with typical pelagic sedimentation rates of a few cm/kyr. © 2013 Elsevier B.V.
Karst S.M.,University of Florida
Gut Microbes | Year: 2015
Human noroviruses are a leading cause of gastroenteritis worldwide but research on these important enteric pathogens has long been restricted by their uncultivability. Extensive efforts to infect intestinal epithelial cells with murine and human noroviruses in vitro have been thus far unsuccessful while murine noroviruses efficiently and lytically infect innate immune cells including macrophages and dendritic cells. We have recently discovered that murine and human noroviruses infect B cells in vitro. The nature of B cell infection was distinct from innate immune cell infection in that mature B cells were infected noncytopathically in contrast to the lytic infection of macrophages and dendritic cells. Human norovirus infection of B cells was facilitated by commensal bacteria expressing an appropriate histo-blood group antigen. Importantly, we used the mouse model of norovirus infection to confirm that Peyer's patch B cells are infected, and that commensal bacteria stimulate infection, in vivo. © 2015, Taylor & Francis Group, LLC.
Zolotukhin S.,University of Florida
Oral Diseases | Year: 2013
The salivary proteome consists of thousands of proteins, which include, among others, hormonal modulators of energy intake and output. Although the functions of this prominent category of hormones in whole body energy metabolism are well characterized, their functions in the oral cavity, whether as a salivary component, or when expressed in taste cells, are less studied and poorly understood. The respective receptors for the majority of salivary metabolic hormones have been also shown to be expressed in salivary glands (SGs), taste cells, or other cells in the oral mucosa. This review provides a comprehensive account of the gastrointestinal hormones, adipokines, and neuropeptides identified in saliva, SGs, or lingual epithelium, as well as their respective cognate receptors expressed in the oral cavity. Surprisingly, few functions are assigned to salivary metabolic hormones, and these functions are mostly associated with the modulation of taste perception. Because of the well-characterized correlation between impaired oral nutrient sensing and increased energy intake and body mass index, a conceptually provocative point of view is introduced, whereupon it is argued that targeted changes in the composition of saliva could affect whole body metabolism in response to the activation of cognate receptors expressed locally in the oral mucosa. © 2012 John Wiley & Sons A/S.
Rittschof C.C.,University of Florida
Behavioral Ecology | Year: 2010
Across a variety of animal taxa, the outcome of male-male contests depends on male body size; winners are usually the larger males or the males with bigger weapons. However, high male density can either increase or reverse large-male advantage because density changes the frequency and intensity of male-male interactions. In the golden orb-web spider Nephila clavipes, large males have a competitive advantage in male-male contests. However, this species shows more than 2-fold variation in male body size and highly variable local male density (the number of males on a female's web). To test how male density affects large-male advantage, I manipulated male density on female webs. I measured how density affects the rate of male-male challenges and the body size of successful males. Large males have a reproductive advantage when male density is high and fighting among males is intense, but small and large males are equally likely to copulate successfully when male density is low, possibly because male-male interactions are infrequent at low densities. High variance in male density among female webs and the positive relationship between density and the strength of sexual selection for male body size create a heterogeneous mosaic of selection intensities. Spatial variation in selection intensity could act to maintain variation in male body size in this species. © 2010 The Author.
Staud R.,University of Florida
Clinical and Experimental Rheumatology | Year: 2011
Fibromyalgia (FM) is a chronic musculoskeletal pain syndrome which is characterised by clinical pain as well as widespread hyperalgesia/'allodynia to mechanical, thermal, electrical, and chemical stimuli. Lack of consistent tissue abnormalities in FM patients has more and more shifted the focus away from peripheral factors and towards central nervous system abnormalities including central sensitisation as well as aberrant pain facilitation and inhibition. Besides quantitative sensory testing, functional brain imaging has been increasingly utilised to characterise the abnormal pain processing of FM patients. Whereas initial work in FM patients identified abnormally increased pain-related brain activity within the thalamus, insula, anterior cingulate, S1, and prefrontal cortex (so-called "pain matrix"), more recent research focused on altered "connectivity" between multiple interconnected brain networks in these patients. Additionally, magnetic resonance spectroscopy studies demonstrated high concentration of the excitatory neurotransmitter glutamate in FM patients in pain-related brain areas which correlated not only with experimental but also with clinical pain ratings. Overall, functional brain imaging studies have provided compelling evidence for abnormal pain processing in FM, including brain activity that correlated with patients' augmented pain sensitivity (hyperalgesia/allodynia), temporal summation of pain, and prolonged pain aftersensations. Future imaging work needs to focus on identifying the neural correlates of FM patients' abnormal endogenous pain modulation which will likely not only shed more light on this important pain regulatory mechanism but may also provide useful information for future treatments of FM symptoms. © Copyright CLINICAL AND EXPERIMENTAL RHEUMATOLOGY 2011.
Maupin-Furlow J.A.,University of Florida
Trends in Microbiology | Year: 2013
This review highlights the finding that ubiquitin-like (Ubl) proteins of archaea (termed SAMPs) function not only as sulfur carriers but also as protein modifiers. UbaA (an E1 ubiquitin-activating enzyme homolog of archaea) is required for the SAMPs to be covalently attached to proteins. The SAMPs and UbaA are also needed to form sulfur-containing biomolecules (e.g., thiolated tRNA and molybdenum cofactor). These findings provide a new perspective on how Ubl proteins can serve as both sulfur carriers and protein modifiers in the absence of canonical E2 ubiquitin conjugating or E3 ubiquitin ligase enzyme homologs. © 2012 Elsevier Ltd.
Weppelmann T.A.,University of Florida
Malaria journal | Year: 2013
Malaria is a significant public health concern in Haiti where approximately 30,000 cases are reported annually with CDC estimates as high as 200,000. Malaria infections in Haiti are caused almost exclusively by Plasmodium falciparum, while a small number of Plasmodium malariae and an even smaller number of putative Plasmodium vivax infections have been reported. The lack of confirmed P. vivax infections in Haiti could be due to the genetic background of native Haitians. Having descended from West African populations, many Haitians could be Duffy negative due to a single nucleotide polymorphism from thymine to cytosine in the GATA box of the promoter region of the Duffy antigen receptor for chemokines (DARC) gene. This mutation, encoded by the FYES allele, eliminates the expression of the Duffy antigen on erythrocytes, which reduces invasion by P. vivax. This study investigated the frequency of the FYES allele and P. vivax infections in malaria patients with the goal of uncovering factors for the lack of P. vivax infections reported in Haiti. DNA was extracted from dried blood spots collected from malaria patients at four clinic locations in Haiti. The samples were analysed by polymerase chain reaction (PCR) for the presence of the P. vivax small subunit ribosomal RNA gene. PCR, sequencing, and restriction enzyme digestion were used to detect the presence of the FYES allele. Matched samples were examined for both presence of P. vivax and the FYES allele. No cases of P. vivax were detected in any of the samples (0/136). Of all samples tested for the FYES allele, 99.4% had the FYES allele (163/164). Of the matched samples, 99% had the FYES allele (98/99). In this preliminary study, no cases of P. vivax were confirmed by PCR and 99% of the malaria patients tested carried the FYES allele. The high frequency of the FYES allele that silences erythroid expression of the Duffy antigen offers a biologically plausible explanation for the lack of P. vivax infections observed. These results provide insights on the host susceptibility for P. vivax infections that has never before been investigated in Haiti.
Krediet C.J.,University of Florida
Proceedings. Biological sciences / The Royal Society | Year: 2013
Over the last decade, significant advances have been made in characterization of the coral microbiota. Shifts in its composition often correlate with the appearance of signs of diseases and/or bleaching, thus suggesting a link between microbes, coral health and stability of reef ecosystems. The understanding of interactions in coral-associated microbiota is informed by the on-going characterization of other microbiomes, which suggest that metabolic pathways and functional capabilities define the 'core' microbiota more accurately than the taxonomic diversity of its members. Consistent with this hypothesis, there does not appear to be a consensus on the specificity in the interactions of corals with microbial commensals, even though recent studies report potentially beneficial functions of the coral-associated bacteria. They cycle sulphur, fix nitrogen, produce antimicrobial compounds, inhibit cell-to-cell signalling and disrupt virulence in opportunistic pathogens. While their beneficial functions have been documented, it is not certain whether or how these microbes are selected by the hosts. Therefore, understanding the role of innate immunity, signal and nutrient exchange in the establishment of coral microbiota and in controlling its functions will probably reveal ancient, evolutionarily conserved mechanisms that dictate the outcomes of host-microbial interactions, and impact the resilience of the host.
Woodard R.P.,University of Florida
Foundations of Physics | Year: 2014
I review a class of nonlocally modified gravity models which were proposed to explain the current phase of cosmic acceleration without dark energy. Among the topics considered are deriving causal and conserved field equations, adjusting the model to make it support a given expansion history, why these models do not require an elaborate screening mechanism to evade solar system tests, degrees of freedom and kinetic stability, and the negative verdict of structure formation. Although these simple models are not consistent with data on the growth of cosmic structures many of their features are likely to carry over to more complicated models which are in better agreement with the data. © 2014 Springer Science+Business Media New York.
Bartlett R.J.,University of Florida
Wiley Interdisciplinary Reviews: Computational Molecular Science | Year: 2012
Coupled-cluster theory offers today's reference quantum chemical method for most of the problems encountered in electronic structure theory. It has been instrumental in establishing the now well-known paradigm of converging, many-body methods, Many-body perturbation theory (MBPT) for second, MBPT2, and fourth-order MBPT4; and coupled-cluster (CC) theory for different categories of excitations, singles, doubles, triples, quadruples (SDTQ). Although built on the same basic concept as configuration interaction (CI), many-body methods fundamentally improve upon CI approximations by introducing the property of size extensivity, meaning that contrary to any truncated CI all terms properly scale with the number of electrons in the problem. This fundamental aspect of many-electron methods leads to the exceptional performance of CC theory and its finite-order MBPT approximations plus its equation-of-motion extensions for excited, ionized, and electron attached states. This brief overview will describe formal aspects of the theory which should be understood by perspective users of CC methods. We will also comment on some current developments that are improving the theory's accuracy or applicability. © 2011 John Wiley & Sons, Ltd.
Will C.M.,University of Florida
Living Reviews in Relativity | Year: 2014
The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed and updated. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves.
Dwyer J.R.,Florida Institute of Technology |
Uman M.A.,University of Florida
Physics Reports | Year: 2014
Despite being one of the most familiar and widely recognized natural phenomena, lightning remains relatively poorly understood. Even the most basic questions of how lightning is initiated inside thunderclouds and how it then propagates for many tens of kilometers have only begun to be addressed. In the past, progress was hampered by the unpredictable and transient nature of lightning and the difficulties in making direct measurements inside thunderstorms, but advances in instrumentation, remote sensing methods, and rocket-triggered lightning experiments are now providing new insights into the physics of lightning. Furthermore, the recent discoveries of intense bursts of X-rays and gamma-rays associated with thunderstorms and lightning illustrate that new and interesting physics is still being discovered in our atmosphere. The study of lightning and related phenomena involves the synthesis of many branches of physics, from atmospheric physics to plasma physics to quantum electrodynamics, and provides a plethora of challenging unsolved problems. In this review, we provide an introduction to the physics of lightning with the goal of providing interested researchers a useful resource for starting work in this fascinating field. © 2013 Elsevier B.V.
Bartlett R.J.,University of Florida
Molecular Physics | Year: 2010
Today's electronic structure theory depends equally upon density functional theory (DFT) and wavefunction theory (WFT). The interconnections between the two has long been of interest, but has not been developed explicitly enough to enable the best of both worlds to be used to obtain improved results. ab initio dft has been pursued at QTP over a few years as a partial solution. ab initio dft combines elements of correlated WFT, by taking orbital dependent functionals from coupled-cluster and many-body perturbation theory with optimised potential ideas to offer a seamless connection. The emphasis has been on the correlation potentials used in Kohn-Sham theory rather than the functionals themselves, as the potential is more sensitive to various approximations. This contribution summarises that work and suggests some future developments. © 2010 Taylor & Francis.
Bartlett R.J.,University of Florida
Molecular Physics | Year: 2010
The elements of coupled-cluster (CC) theory that distinguish it from other ways of treating the correlation problem are presented. These essential components required that new theory be developed to treat analytical gradients, excited states, higher order properties, and now multi-reference CC. Aided by these developments, CC theory provides the best answers for the largest number of problems in molecular structure and spectra. Many scientists who spent time at the Quantum Theory Project were instrumental in these developments. © 2010 Taylor & Francis.
Gold M.S.,University of Florida
Physiology and Behavior | Year: 2011
My work (Mark S. Gold) began in the 70s looking for the mechanisms of drug reinforcement and withdrawal. Through observation and experience, drugs of abuse and the drive for food appeared to be quite related. As pioneered by Bart Hoebel, food can become an object of desire and act in most respects as a drug of abuse. The Gold lab is investigating working models for pathological attachment to eating and food addiction. New pharmacological treatments which interfere with food reinforcement may be the next step. © 2011 Elsevier Inc.
Kalra S.P.,University of Florida
Gene Therapy | Year: 2011
The incidence of diabetes mellitus has soared to epidemic proportion worldwide. The debilitating chronic hyperglycemia is caused by either lack of insulin as in diabetes type 1 or its ineffectiveness as in diabetes type 2. Frequent replacement of insulin with or without insulin analogs for optimum glycemic control are the conventional cumbersome therapies. Recent application of leptin gene transfer technology has uncovered the participation of adipocytes-derived leptin-dependent hypothalamic neural signaling in glucose homeostasis and demonstrated that a breakdown in this communication due to leptin insufficiency in the hypothalamus underlies the etiology of chronic hyperglycemia. Reinstatement of central leptin sufficiency by hyperleptinemia produced either by intravenous leptin infusion or a single systemic injection of recombinant adenovirus vector encoding leptin gene suppressed hyperglycemia and evoked euglycemia only transiently in rodent models of diabetes type 1. In contrast, stable restoration of leptin sufficiency, solely in the hypothalamus, with biologically active leptin transduced by an intracerebroventicular injection of recombinant adeno-associated virus vector encoding leptin gene (rAAV-lep) abolished hyperglycemia and imposed euglycemia through the extended duration of experiment by stimulating glucose disposal in the periphery in models of diabetes type 1. Further, similar hypothalamic leptin transgene expression abrogated chronic hyperglycemia and hyperinsulinemia, the predisposing risk factors of the age and environmentally acquired diabetes type 2, and instituted euglycemia by independently activating relays that stimulate glucose metabolism and repress hyperinsulinemia and improve insulin sensitivity in the periphery. Consequently, this durable antidiabetic efficacy of one time rAAV-lep neurotherapy offers a potential novel substitute for insulin therapy following preclinical trials in subhuman primates and humans. © 2011 Macmillan Publishers Limited All rights reserved.
Xue J.,University of Florida
Polymer Reviews | Year: 2010
Organic photovoltaics have been considered as a future low-cost solar energy conversion solution, and have attracted tremendous academic and industrial interests in recent years due to many technological advantages of organic semiconductors (including both small molecules and conjugated polymers). Here we describe the basic design and operation of organic photovoltaic cells as well as the important metrics for characterizing their performance. An overview of the three review articles included in this special issue on organic photovoltaics is provided, followed by discussions on the remaining significant challenges for the further development and commercialization of the organic photovoltaic technologies. Copyright © Taylor & Francis Group, LLC.
Stitt G.,University of Florida
IEEE Micro | Year: 2011
Although field-programmable gate arrays (FPGAs) can offer a significant performance advantage over alternate devices, they remain a niche technology. This column addresses the barriers to widespread FPGA use and explores the innovations necessary to eliminate these barriers. © 2011 IEEE.
Battaglia M.,San Raffaele Scientific Institute |
Atkinson M.A.,University of Florida
Diabetes | Year: 2015
In the nearly 100 years since the discovery of therapeutic insulin, significant research efforts have been directed at finding the underlying cause of type 1 diabetes (T1D) and developing a "cure" for the disease. While progress has clearly been made toward each of these goals, neither vision has been fulfilled. With increasing pressure from both public and private funders of diabetes research, growing impatience of those with T1D at the lack of practical discoveries, increased competition for research funds, uncertainties on the reproducibility of published scientific data, and questions regarding the value of animal models, the current research environment has become extraordinarily difficult to traverse from the perspective of investigators. As a result, there is an increasing pressure toward performance of what might be considered "safe" research, where the aim is to affirm existing dogmas rather than to pioneer efforts involving unconventional thought. Psychologists refer to this practice as "observational bias" while cartoonists label the process the "streetlight effect." In this Perspective, we consider notions in T1D research that should be subject to bold question and provide additional concepts, many somewhat orphan to research efforts, whose investigation could lead to a means for truly identifying the cause of and a cure for T1D. © 2015 by the American Diabetes Association.
Tebbe E.N.,University of Florida
Journal of counseling psychology | Year: 2012
This study aimed to identify theoretically relevant key correlates of anti-transgender prejudice. Specifically, structural equation modeling was used to test the unique relations of anti-lesbian, gay, and bisexual (LGB) prejudice; traditional gender role attitudes; need for closure; and social dominance orientation with anti-transgender prejudice. Social desirability was controlled as a covariate in the model. Analyses of data from 250 undergraduate students indicated that anti-LGB prejudice, traditional gender role attitudes, and need for closure each had positive unique relations with anti-transgender prejudice beyond the negative association of social desirability with such prejudice. By contrast, social dominance orientation was not related uniquely to anti-transgender prejudice. Additional analyses indicated that women's mean level of anti-transgender prejudice was lower than that of men's, but the pattern of relations between the predictor variables and anti-transgender prejudice did not differ between women and men. A confirmatory factor analysis also supported the unidimensional structure of anti-transgender prejudice as operationalized by Nagoshi et al.'s (2008) Transphobia Scale.
Kazory A.,University of Florida
American Journal of Cardiology | Year: 2010
The nonosmotic release of arginine vasopressin, concurrent with the activation of the sympathetic nervous system and renin-angiotensin-aldosterone system, is thought to represent the maladaptive response that is central to the pathophysiology of heart failure (HF). The degree of neurohormonal activation correlates with the severity of the disease and can predict the outcomes. However, quantification of components of neurohormonal axis (e.g., serum arginine vasopressin level) is mainly reserved for research purposes rather than routine practice. The results of several recent HF trials have shed light on the differential role of blood urea nitrogen (BUN) and creatinine in predicting the outcomes in this setting. These studies suggest that BUN could indeed represent a surrogate marker for "renal response" to neurohormonal activation in this setting, above and beyond its role in the estimation of renal function. In this report, the relevant physiologic mechanisms underlying urea and water transport in the kidney are first reviewed. Then, the activation of the neurohormonal axis and the impact of its components on renal urea transport, independent of changes in renal function, are explained. Finally, the unique role of BUN as a biomarker of neurohormonal activation in the setting of HF is discussed, and the potential clinical implication of this novel concept is emphasized. In conclusion, this review explains the pathophysiologic basis for the emerging role of BUN as a biomarker in HF. © 2010 Elsevier Inc. All rights reserved.
Pacak C.A.,Harvard University |
Byrne B.J.,University of Florida
Molecular Therapy | Year: 2011
Since the first demonstration of in vivo gene transfer into myocardium there have been a series of advancements that have driven the evolution of cardiac gene delivery from an experimental tool into a therapy currently at the threshold of becoming a viable clinical option. Innovative methods have been established to address practical challenges related to tissue-type specificity, choice of delivery vehicle, potency of the delivered material, and delivery route. Most importantly for therapeutic purposes, these strategies are being thoroughly tested to ensure safety of the delivery system and the delivered genetic material. This review focuses on the development of recombinant adeno-associated virus (rAAV) as one of the most valuable cardiac gene transfer agents available today. Various forms of rAAV have been used to deliver pre-event cardiac protection and to temper the severity of hypertrophy, cardiac ischemia, or infarct size. Adeno-associated virus (AAV) vectors have also been functional delivery tools for cardiac gene expression knockdown studies and successfully improving the cardiac aspects of several metabolic and neuromuscular diseases. Viral capsid manipulations along with the development of tissue-specific and regulated promoters have greatly increased the utility of rAAV-mediated gene transfer. Important clinical studies are currently underway to evaluate AAV-based cardiac gene delivery in humans. © 2011 The American Society of Gene & Cell Therapy.
Nassif N.,University of Florida
Energy and Buildings | Year: 2010
HVAC systems and associated equipment consume a relatively large fraction of total building energy consumption, a significant portion of which is attributed to fan operation. The operation of economizer dampers when installed can cause high energy consumption in fans if they are not functioning in proper and optimal manner. This will mainly be due to the potential high pressure drops through those dampers and associated high total pressures that should be developed by supply and/or return fans. It is then necessary to ensure that a proper strategy to operate optimally the economizer dampers is implemented with minimum fan energy use. The paper examines several operation strategies of the economizer dampers and investigates their effects on the performance of both the supply and return fans in HVAC system. It also discusses a new operating strategy for economizer dampers that can lead to lower fan energy use. The strategies are evaluated by simulations for a typically existing HVAC system. Several factors such as the building locations, system characteristics, resistance in the duct where the dampers are installed, supply air temperature and economizer control, and minimum ventilation requirements are also considered during the evaluations. The results show that the way of the economizer dampers been controlled has a significant effect on fan performance and its energy use. The proposed strategy if properly implemented can provide fan energy saving in the range of 5-30%, depending mainly on the number of hours when the system operates in the free cooling mode, damper characteristics, and minimum outdoor air. © 2010 Elsevier B.V. All rights reserved.
Shriner R.L.,University of Florida
Experimental Gerontology | Year: 2013
The senior patient and/or the geriatrician are confronted with a confusing literature describing how patients interested in combating metabolic syndrome, diabesity (diabetes plus obesity) or simple obesity might best proceed. The present paper gives a brief outline of the basic disease processes that underlie metabolic pro-inflammation, including how one might go about devising the most potent and practical detoxification from such metabolic compromise. The role that dietary restriction plays in pro-inflammatory detoxification (. detox), including how a modified fast (selective food abstinence) is incorporated into this process, is developed. The unique aspects of geriatric bariatric medicine are elucidated, including the concepts of sarcopenia and the obesity paradox. Important caveats involving the senior seeking weight loss are offered. By the end of the paper, the reader will have a greater appreciation for the challenges and opportunities that lie ahead for geriatric patients who wish to overcome food addiction and reverse pro-inflammatory states of ill-heath. This includes the toxic metabolic processes that create obesity complicated by type 2 diabetes mellitus (T2DM) which collectively we call diabesity. In that regard, diabesity is often the central pathology that leads to the evolution of the metabolic syndrome. The paper also affords the reader a solid review of the neurometabolic processes that effectuate anorexigenic versus orexigenic inputs to obesity that drive food addiction. We argue that these processes lead to either weight gain or weight loss by a tripartite system involving metabolic, addictive and relational levels of organismal functioning. Recalibrating the way we negotiate these three levels of daily functioning often determines success or failure in terms of overcoming metabolic syndrome and food addiction. © 2013 Elsevier Inc.
Szymczak P.,University of Warsaw |
Ladd A.J.C.,University of Florida
Earth and Planetary Science Letters | Year: 2011
The solutional origin of limestone caves was recognized over a century ago, but the short penetration length of an undersaturated solution made it seem impossible for long conduits to develop. This is contradicted by field observations, where extended conduits, sometimes several kilometers long, are found in karst environments. However, a sharp drop in the dissolution rate of CaCO3 near saturation provides a mechanism for much deeper penetration of reactant. The notion of a "kinetic trigger" - a sudden change in rate constant over a narrow concentration range - has become a widely accepted paradigm in speleogenesis modeling. However, it is based on one-dimensional models for the fluid and solute transport inside the fracture, assuming that the dissolution front is planar in the direction perpendicular to the flow. Here we show that this assumption is incorrect; a planar dissolution front in an entirely uniform fracture is unstable to infinitesimal perturbations and inevitably breaks up into highly localized regions of dissolution. This provides an alternative mechanism for cave formation, even in the absence of a kinetic trigger. Our results suggest that there is an inherent wavelength to the erosion pattern in dissolving fractures, which depends on the reaction rate and flow rate, but is independent of the initial roughness. In contrast to one-dimensional models, two-dimensional simulations indicate that there is only a weak dependence of the breakthrough time on kinetic order; localization of the flow tends to keep the undersaturation in the dissolution front above the threshold for non-linear kinetics. © 2010 Elsevier B.V.
Shriner R.L.,University of Florida
Current Pharmaceutical Design | Year: 2011
as obesity, type 2 diabetes (T2DM) and the metabolic syndrome sweep across the research and the clinical landscape of medicalcare, effective pharmacologic remedies for the treatment of obesity have become imperative. The complexities of nutrient impact onneurotransmitter and endocrine modulating chemistry have become increasingly better characterized as have the basic neurochemicalpathways that mediate their effects. Food addiction has emerged as an important phenomenon that may help to explain and improve ourcapabilities of rendering bench lab research into impactful clinical intervention. Against this challenging backdrop of current research andstudy we introduce the notion that food may, itself, represent a type of drug. In this review of food as a drug, we outline some of theemerging science that argues how proteins, carbohydrates and fats operating on three basic levels of organismic functioning may constitutethe most powerful drugs we have available to effectuate weight loss or weight gain over time. In addition, certain foods may not onlybe more addictive than others, but may actually have a direct effect on pro-inflammatory mediators that determine both metabolic dysfunctionas well as overall neuropsychiatric function and well-being. © 2011 Bentham Science Publishers Ltd.
Avena N.M.,University of Florida |
Bocarsly M.E.,Princeton University
Neuropharmacology | Year: 2012
Food intake is mediated, in part, through brain pathways for motivation and reinforcement. Dysregulation of these pathways may underlay some of the behaviors exhibited by patients with eating disorders. Research using animal models of eating disorders has greatly contributed to the detailed study of potential brain mechanisms that many underlie the causes or consequences of aberrant eating behaviors. This review focuses on neurochemical evidence of reward-related brain dysfunctions obtained through animal models of binge eating, bulimia nervosa, or anorexia nervosa. The findings suggest that alterations in dopamine (DA), acetylcholine (ACh) and opioid systems in reward-related brain areas occur in response to binge eating of palatable foods. Moreover, animal models of bulimia nervosa suggest that while bingeing on palatable food releases DA, purging attenuates the release of ACh that might otherwise signal satiety. Animal models of anorexia nervosa suggest that restricted access to food enhances the reinforcing effects of DA when the animal does eat. The activity-based anorexia model suggests alterations in mesolimbic DA and serotonin occur as a result of restricted eating coupled with excessive wheel running. These findings with animal models complement data obtained through neuroimaging and pharmacotherapy studies of clinical populations. Information on the neurochemical consequences of the behaviors associated with these eating disorders will be useful in understanding these complex disorders and may inform future therapeutic approaches, as discussed here. This article is part of a Special Issue entitled 'Central Control of Food Intake'. © 2012 Elsevier Ltd. All rights reserved.
Tandon R.,University of Florida
Psychiatric Clinics of North America | Year: 2012
Although dementia praecox or schizophrenia has been considered a unique disease entity for more than a century, definitions and boundaries have changed and its precise cause and pathophysiology remain elusive. Despite uncertain validity, the construct of schizophrenia conveys useful clinical and etiopathophysiologic information. Revisions of the Diagnostic and Statistical Manual of Mental Disorders and the International Classification of Diseases seek to incorporate new information about schizophrenia and include elimination of subtypes, addition of psychopathological dimensions, elimination of special treatment of Schneiderian "first-rank" symptoms, better delineation of schizoaffective disorder, and addition of a new category of "attenuated psychosis syndrome" © 2012.
Daaka Y.,University of Florida
Biochimica et Biophysica Acta - General Subjects | Year: 2012
G protein-coupled receptors (GPCRs) are the most numerous and diverse type of cell surface receptors, accounting for about 1% of the entire human genome and relaying signals from a variety of extracellular stimuli that range from lipid and peptide growth factors to ions and sensory inputs. Activated GPCRs regulate a multitude of target cell functions, including intermediary metabolism, growth and differentiation, and migration and invasion. The GPCRs contain a characteristic 7-transmembrane domain topology and their activation promotes complex formation with a variety of intracellular partner proteins, which form basis for initiation of distinct signaling networks as well as dictate fate of the receptor itself. Both termination of active GPCR signaling and removal from the plasma membrane are controlled by protein post-translational modifications of the receptor itself and its interacting partners. Phosphorylation, acylation and ubiquitination are the most studied post-translational modifications involved in GPCR signal transduction, subcellular trafficking and overall expression. Emerging evidence demonstrates that protein S-nitrosylation, the covalent attachment of a nitric oxide moiety to specified cysteine thiol groups, of GPCRs and/or their associated effectors also participates in the fine-tuning of receptor signaling and expression. This newly appreciated mode of GPCR system modification adds another set of controls to more precisely regulate the many cellular functions elicited by this large group of receptors. This article is part of a Special Issue entitled: Regulation of cellular processes by S-nitrosylation. © 2011 Elsevier B.V. All rights reserved.
Balachandar S.,University of Florida |
Eaton J.K.,Stanford University
Annual Review of Fluid Mechanics | Year: 2010
Turbulent dispersed multiphase flows are common in many engineering and environmental applications. The stochastic nature of both the carrier-phase turbulence and the dispersed-phase distribution makes the problem of turbulent dispersed multiphase flow far more complex than its single-phase counterpart. In this article we first review the current state-of-the-art experimental and computational techniques for turbulent dispersed multiphase flows, their strengths and limitations, and opportunities for the future. The review then focuses on three important aspects of turbulent dispersed multiphase flows: the preferential concentration of particles, droplets, and bubbles; the effect of turbulence on the coupling between the dispersed and carrier phases; and modulation of carrier-phase turbulence due to the presence of particles and bubbles. Copyright © 2010 by Annual Reviews. All rights reserved.
Ewel K.C.,University of Florida
Frontiers in Ecology and the Environment | Year: 2010
The Ecological Society of America Freshwater forested wetlands are often found just upslope from mangrove forests in both high- and low-rainfall areas in the tropics. A case study on the island of Kosrae, Federated States of Micronesia, demonstrates how important both wetland types are to each other hydrologically and to local economies as well. Together, these wetlands form a landscape that provides goods worth the equivalent of nearly two-thirds the median household income in the region. Elsewhere around the world, similar contiguous pairs of wetlands are extensively used by local populations. However, while the importance of mangroves is well recognized, goods and services provided by freshwater wetlands - which are also much threatened by coastal development - are not nearly so well documented. Because such landscapes provide sustenance for millions of people, the natural and socioeconomic roles that both types of wetlands play must be better understood and protected as plans for coastal development proceed.
Kile J.,University of Florida |
Kobach A.,Northwestern University |
Soni A.,Brookhaven National Laboratory
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015
In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV-1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. μ→3e, τ→eμμ, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10-100 TeV), whereas the 3.6σ deviation of the muon g-2 from the standard model can be explained by a new-physics scale
Kobeissy F.H.,University of Florida
PM & R : the journal of injury, function, and rehabilitation | Year: 2011
Although traumatic brain injury (TBI) remains a major health problem, with approximately 2 million incidents occurring annually in the United States, no therapeutic agents to treat TBI have been approved by the Food and Drug Administration despite several clinical trials. It is estimated that 3.5 million Americans now have a lifelong condition that might be termed "chronic traumatic brain injury disease.'' Some health care providers categorize TBI as an "event" for which patients require brief periods of rehabilitation with no further treatment. On the contrary, TBI should be seen as a chronic disease process that fits the World Health Organization definition as being a non-reversible pathologic condition requiring special rehabilitation training. Among the major obstacles that contribute to this type of misconception is the absence of brain injury-specific diagnostic biomarker(s) that can indicate and monitor the long-term health status of patients with TBI after use of conventional therapeutics and a rehabilitation process. It is of interest that recent advances in genomics, proteomics, and systems biology have enabled us to use these high throughput-based approaches in developing biomarkers and therapeutic targets in the area of TBI. One aim of this article is to provide an overview that evaluates the current status of TBI biomarker discovery using neuroproteomics/systems biology techniques, along with their clinical utilization. In addition, we discuss the need for strengthening the role of biomarker-based neuroproteomics/systems biology and its potential utility in the field of rehabilitation, which would lead to the establishment of rehabilomics studies, where biomarkers would indicate and predict the long-term efficacy and health status of patients with chronic TBI conditions. Copyright © 2011 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.
Joffe D.,University of Florida
American Journal of Health-System Pharmacy | Year: 2010
Purpose. The pharmacology, pharmacokinetics, efficacy, safety, dosage and administration, adverse effects, and place in therapy of liraglutide, a glucagonlike peptide-1 (GLP-1) receptor agonist, are reviewed. Summary. Liraglutide, the first once-daily human GLP-1 analogue, retains 97% homology with the endogenous hormone and shares its glucose-dependent glucoselowering action but has a considerably longer half-life that supports once-daily dosing. After promising Phase II study results, the Liraglutide Effect and Action in Diabetes (LEAD) Phase III clinical development program, involving more than 4000 patients worldwide, investigated the efficacy and tolerability of liraglutide 1.2 or 1.8 mg daily (n = 2735) as monotherapy and in combination with various oral antidiabetic drugs. The LEAD studies yielded encouraging results indicating that patients receiving liraglutide could expect to attain glycosylated hemoglobin reductions of about 1-1.5% and fasting plasma glucose reductions of 15-43 mg/dL. Loss of body weight was consistent throughout the studies: when using liraglutide 1.8 mg as monotherapy, patients lost a mean of 2.5 kg over a 52-week period. Accompanying reductions in some cardiovascular risk endpoints, such as systolic blood pressure, were also observed. By virtue of its glucose-dependent mode of action, liraglutide was generally well tolerated in clinical trials, with only very rare episodes of major hypoglycemia reported. The most frequently observed adverse effects were gastrointestinal, with 10-40% of patients experiencing an episode of nausea, which was often mild or moderate in severity and transient in nature. Conclusion. Liraglutide is efficacious and well tolerated in patients with type 2 diabetes and has been found to reduce weight and blood pressure. Copyright © 2010, American Society of Health-System Pharmacists, Inc. All rights reserved.
Rahman M.,University of Florida
Neurosurgical focus | Year: 2010
Given the tremendous success of deep brain stimulation (DBS) for the treatment of movement and neuropsychiatric disorders, clinicians have begun to open up to the possible use of electrical stimulation for the treatment of patients with uncontrolled seizures. This process has resulted in the discovery of a wide array of DBS targets, including the cerebellum, hypothalamus, hippocampus, basal ganglia, and various thalamic nuclei. Despite the ambiguity of the mechanism of action and the unknowns surrounding potentially ideal stimulation settings, several recent trials have empirically demonstrated reasonable efficacy in selected cases of medication-refractory seizures. These exciting results have fueled a number of studies aimed at firmly establishing DBS as an effective treatment for selected cases of intractable epilepsy, and many companies are aiming at Food and Drug Administration approval. We endeavor to review the studies in the context of the various DBS targets and their relevant circuitry for epilepsy. Based on the unfolding research, DBS has the potential to play an important role in treating refractory epilepsy. The challenge, as in movement disorders, is to assemble interdisciplinary teams to screen, implant, and follow patients, and to clarify patient selection. The future will undoubtedly be filled with optimization of targets and stimulation parameters and the development of best practices. With tailored therapeutic approaches, epilepsy patients have the potential to improve with DBS.
Knutson M.D.,University of Florida
Annual Review of Nutrition | Year: 2010
The human body cannot actively excrete excess iron. As a consequence, iron absorption must be strictly regulated to ensure adequate iron uptake and prevent toxic iron accumulation. Iron absorption is controlled chiefly by hepcidin, the iron-regulatory hormone. Produced by the liver and secreted into the circulation, hepcidin regulates iron metabolism by inhibiting iron release from cells, including duodenal enterocytes, which mediate the absorption of dietary iron. Hepcidin production increases in response to iron loading and decreases in iron deficiency. Such regulation of hepcidin expression serves to modulate iron absorption to meet body iron demand. This review discusses the proteins that orchestrate hepatic hepcidin production and iron absorption by the intestine. Emphasis is placed on the proteins that directly sense iron and how they coordinate and fine-tune the molecular, cellular, and physiologic responses to iron deficiency and overload. Copyright © 2010 by Annual Reviews. All rights reserved.
Wennier S.,University of Florida
Expert reviews in molecular medicine | Year: 2011
Within the past decade, many oncolytic viruses (OVs) have been studied as potential treatments for pancreatic cancer and some of these are currently under clinical trials. The applicability of certain OVs, such as adenoviruses, herpesviruses and reoviruses, for the treatment of pancreatic cancer has been intensively studied for several years, whereas the applicability of other more recently investigated OVs, such as poxviruses and parvoviruses, is only starting to be determined. At the same time, studies have identified key characteristics of pancreatic cancer biology that provide a better understanding of the important factors or pathways involved in this disease. This review aims to summarise the different replication-competent OVs proposed as therapeutics for pancreatic cancer. It also focuses on the unique biology of these viruses that makes them exciting candidate virotherapies for pancreatic cancer and discusses how they could be genetically manipulated or combined with other drugs to improve their efficacy based on what is currently known about the molecular biology of pancreatic cancer.
Rice K.G.,University of Florida
Journal of counseling psychology | Year: 2012
Using a cross-panel design and data from 2 successive cohorts of college students (N = 357), we examined the stability of maladaptive perfectionism, procrastination, and psychological distress across 3 time points within a college semester. Each construct was substantially stable over time, with procrastination being especially stable. We also tested, but failed to support, a mediational model with Time 2 (mid-semester) procrastination as a hypothesized mechanism through which Time 1 (early-semester) perfectionism would affect Time 3 (end-semester) psychological distress. An alternative model with Time 2 perfectionism as a mediator of the procrastination-distress association also was not supported. Within-time analyses revealed generally consistent strength of effects in the correlations between the 3 constructs over the course of the semester. A significant interaction effect also emerged. Time 1 procrastination had no effect on otherwise high levels of psychological distress at the end of the semester for highly perfectionistic students, but at low levels of Time 1 perfectionism, the most distressed students by the end of the term were those who were more likely to have procrastinated earlier in the semester. Implications of the stability of the constructs and their association over time, as well as the moderating effects of procrastination, are discussed in the context of maladaptive perfectionism and problematic procrastination.
Soloviev A.,University of Florida
IEEE Transactions on Aerospace and Electronic Systems | Year: 2010
A multi-sensor integrated solution that combines complementary features of the Global Positioning System (GPS), laser scanner, and inertial navigation system (INS) for navigation in challenging urban environments is developed. GPS and the laser scanner-based techniques exhibit complementary features in urban scenarios. The laser scanner-based navigation relies on the availability of structures (lines and surfaces) within the scan range (80 m, typically). Features (such as lines) are first extracted from laser scan images and then used for position and attitude determination. If there is a building wall that blocks the GPS signal, this wall creates a feature in the laser scan image. Vice-versa, for open streets with limited features, the GPS signal is generally unobstructed. Thus the GPS and laser data are combined into an integrated solution architecture. The system architecture developed also exploits INS navigation states for improved solution robustness, e.g., for robust feature association between scan images and for coasting through cases where an insufficient number of combined GPS/laser measurements is available. A tightly coupled GPS/laser scanner INS mechanization is developed and applied for trajectory reconstruction. Actual urban data is used to demonstrate performance characteristics of the multi-sensor integrated solution that is developed. © 2006 IEEE.
Stoller J.K.,Cleveland Clinic |
Brantly M.,University of Florida
COPD: Journal of Chronic Obstructive Pulmonary Disease | Year: 2013
Alpha-1 antitrypsin deficiency (AATD) is relatively common but under-recognized. Indeed, fewer than 10% of the estimated 100,000 Americans with AATD have been diagnosed currently, with common reports of long delays between initial symptoms and first detection and the need to see multiple physicians before diagnosis. Because detection can confer benefits (e.g., identification of at-risk family members, lower smoking likelihood, consideration of augmentation therapy), targeted detection of AATD in at-risk groups such as all symptomatic adults with COPD has been endorsed. Two general approaches to detection have been studied: population-based screening (in which testing is performed in a group for whom no increased risk of having AATD exists) and targeted detection or case-finding (in which testing is confined to those with an attributable condition such as COPD or chronic liver disease). Studies to date have suggested that population-based screening is not cost-effective, whereas targeted detection of AATD has been advocated by official society guidelines. Efforts to enhance detection of AATD individuals have included various approaches, including educational campaigns, provision of free test kits, issuance of reminders with medical reports or within an electronic medical record, and empowering respiratory therapists to conduct testing for AATD in pulmonary function laboratories. Such programs have identified individuals with severe deficiency of alpha-1 antitrypsin in up to 12% of subjects, with considerable variation across series by testing criteria. Overall, the persistence of under-recognition of AATD underscores the need for continued efforts to optimize detection of this potentially debilitating genetic disease. © 2013 Informa Healthcare USA, Inc.
Staud R.,University of Florida
Current Rheumatology Reports | Year: 2012
Fatigue is a common symptom in a large number of medical and psychological disorders, including many rheumatologic illnesses. A frequent question for health care providers is related to whether reported fatigue is "in the mind" or "in the body"-that is, central or peripheral. If fatigue occurs at rest without any exertion, this suggests psychological or central origins. If patients relate their fatigue mostly to physical activities, including exercise, their symptoms can be considered peripheral. However, most syndromes of fatigue seem to depend on both peripheral and central mechanisms. Sometimes, muscle biopsy with histochemistry may be necessary for the appropriate tissue diagnosis, whereas serological tests generally provide little reliable information about the origin of muscle fatigue. Muscle function and peripheral fatigue can be quantified by contractile force and action potential measurements, whereas validated questionnaires are frequently used for assessment of mental fatigue. Fatigue is a hallmark of many rheumatologic conditions, including fibromyalgia, myalgic encephalitis/chronic fatigue syndrome, rheumatoid arthritis, systemic lupus, Sjogren's syndrome, and ankylosing spondylitis. Whereas many studies have focused on disease activity as a correlate to these patients' fatigue, it has become apparent that other factors, including negative affect and pain, are some of the most powerful predictors for fatigue. Conversely, sleep problems, including insomnia, seem to be less important for fatigue. There are several effective treatment strategies available for fatigued patients with rheumatologic disorders, including pharmacological and nonpharmacological therapies. © Springer Science+Business Media, LLC 2012.
Edwards N.L.,University of Florida
Journal of medical economics | Year: 2011
Joint pain and swelling during gout flares may lead to considerable morbidity and disability, having an impact on patient work productivity and social participation. The objective of this study was to assess how gout flares affect these activities in patients with chronic gout refractory to conventional therapy. A 1-year prospective observational study was conducted among patients with symptomatic disease in the United States in 2001. Inclusion criteria required patients (1) to be age 18 years or older, (2) to have documented, crystal-proven gout, (3) to have symptomatic gout, and (4) to be intolerant or unresponsive to conventional therapy, reflected by SUA≥6.0mg/dL. Patients were evaluated every 2 months. At each visit, patients completed a gout diary, which included number of flares experienced, duration and severity of each flare, and whether the flare caused: (1) work loss, (2) missed appointments or social events, or (3) impairment of self-care activities. The Short-Form Health Survey (SF-36) was also completed each visit. Analyses were restricted to those who completed the first 6 months of the study (n=81). Mean number of flares per patient per year was 8.8. Of the patients who were <65 years, 78% reported at least 1 work day lost due to a gout attack during the year. Mean annual work day loss for those <65 years was 25.1 days. A total of 545 of patients reported at least one flare per year that impaired social activities, with a mean of 17.1 social days lost and 52% reported at least one flare per year that compromised normal self-care activities, with a mean of 16.9 days impairment. Correlations between the diary reports and activity-related questions from the SF-36 were significantly positive. The study is limited by small sample size, lack of reference group, and inability to explicitly collect employment information. Age under 65 years was used as a proxy for employment eligibility. Flares in patients with chronic gout refractory to conventional therapy significantly affect patient work productivity and social activities.
Clark B.C.,Ohio University |
Manini T.M.,University of Florida
Nutrition | Year: 2012
Dynapenia (pronounced dahy-nuh-pē-nē-a, Greek translation for poverty of strength, power, or force) is the age-associated loss of muscle strength that is not caused by neurologic or muscular diseases. Dynapenia predisposes older adults to an increased risk for functional limitations and mortality. For the past several decades, the literature has largely focused on muscle size as the primary cause of dynapenia; however, recent findings have clearly demonstrated that muscle size plays a relatively minor role. Conversely, subclinical deficits in the structure and function of the nervous system and/or impairments in the intrinsic force-generating properties of skeletal muscle are potential antecedents to dynapenia. This review highlights in the contributors to dynapenia and the etiology and risk factors that predispose individuals to dynapenia. In addition, we address the role of nutrition in the muscular and neurologic systems for the preservation of muscle strength throughout the life span. © 2012 Elsevier Inc..
Manini T.M.,University of Florida |
Clark B.C.,Ohio University
Journals of Gerontology - Series A Biological Sciences and Medical Sciences | Year: 2012
In 2008, we published an article arguing that the age-related loss of muscle strength is only partially explained by the reduction in muscle mass and that other physiologic factors explain muscle weakness in older adults (Clark BC, Manini TM. Sarcopenia =/= dynapenia. J Gerontol A Biol Sci Med Sci. 2008;63:829-834). Accordingly, we proposed that these events (strength and mass loss) be defined independently, leaving the term "sarcopenia" to be used in its original context to describe the age-related loss of muscle mass. We subsequently coined the term "dynapenia" to describe the age-related loss of muscle strength and power. This article will give an update on both the biological and clinical literature on dynapenia-serving to best synthesize this translational topic. Additionally, we propose a working decision algorithm for defining dynapenia. This algorithm is specific to screening for and defining dynapenia using age, presence or absence of risk factors, a grip strength screening, and if warranted a test for knee extension strength. A definition for a single risk factor such as dynapenia will provide information in building a risk profile for the complex etiology of physical disability. As such, this approach mimics the development of risk profiles for cardiovascular disease that include such factors as hypercholesterolemia, hypertension, hyperglycemia, etc. Because of a lack of data, the working decision algorithm remains to be fully developed and evaluated. However, these efforts are expected to provide a specific understanding of the role that dynapenia plays in the loss of physical function and increased risk for disability among older adults. © 2011 The Author.
Anusavice K.J.,University of Florida
Dental Materials | Year: 2012
"Nothing worthwhile is ever without complications." Nora Roberts The recent increase in reports from clinical studies of ceramic chipping has raised the question of which criteria should constitute success or failure of total-ceramic prostheses. Terminologies such as minor chipping , partial chipping, technical complications [2,3], and biological complications have crept into the dental terminology and they have complicated our classification of success and failure of these crown and bridge restorations. Some journals have permitted the reporting of fractures as "complications" and they are not necessarily classified as failures in the study. One study has attempted to classify chipping fractures according to their severity and subsequent treatment . This is a promising approach to resolve the challenges to the classification of chipping fracture. The term 'chipping fracture' is more descriptive than 'chipping' since the latter term tends to imply an event of minor consequence. Two types of statistics are reported routinely in these studies, i.e., percent success, which is a measure of restorations that survive without any adverse effects, and percent survival, which is a measure of all restorations that survive even though they may have exhibited chipping fracture or they may have been repaired. Why has this scenario occurred? One possible explanation is that many of these types of fractures are very small and do not affect function or esthetics. Another reason is that corporate sponsors prefer to use the term chipping since it does not connote failure in the sense that the term fracture does. In any event, we need to be more precise in our scientific observations of fracture and classifications of the various types of fracture including details on the location of fracture and the prosthesis design configuration. Because of the lack of standardized methods for describing chipping fractures, materials scientists are unable to properly analyze the effect of material properties and design factors on the time-dependent survival probability of ceramic fixed dental prostheses (FDPs). Based on the review of clinical trials and systematic reviews of these trials, the present study was designed to develop guidelines for classifying the functional performance, success, survival, and susceptibility to chipping fracture, and subsequent treatment of ceramic and metal-ceramic restorations. Objective: To develop comprehensive descriptive guidelines and a clinical reporting form to assist dental scientists in their analyses of chipping fracture behavior of metal-ceramic and all-ceramic prostheses with particular emphasis on veneered-zirconia restorations. These guidelines are required to optimize the recording of fracture features that can be used to differentiate ceramic chipping fracture from bulk fracture and to assist dentists in identifying subsequent treatment that may minimize the need to replace affected restorations. A recording form for clinical fracture observations must be sufficiently clear and complete so that dental health professionals can translate the most relevant information in a context that allows their patients to fully understand the potential risks and benefits of treatment with ceramic restorations. It should clearly allow a clinician to determine whether or not a ceramic fracture constitutes a failure, which requires replacement of the prosthesis, or whether the fracture surface is relatively small or located in a nonfunctional area, i.e., one that is not contribute to occlusion, esthetics, proximal contacts, or food impaction. To accomplish this task, a review of the relevant publications of clinical trials was necessary to identify the variability in reporting of fracture events. The reviews were focused on clinical research studies of zirconia-based FDPs and PFM FDPs, which had been monitored through recall exams for three years or more. These reports and systematic reviews of all relevant publications were published in English dental journals between 2004 and 2010.The primary focus in this review was on the susceptibility to chipping fracture or bulk fracture of veneered zirconia-based fixed dental prostheses (FDPs) and metal-ceramic FDPs, which are also referred to in this paper as porcelain-fused-to-metal (PFM) FDPs. © 2011 Academy of Dental Materials.
Kaunitz A.M.,University of Florida |
Inki P.,Bayer AG
Drugs | Year: 2012
Heavy menstrual bleeding (HMB) is a common problem in women of reproductive age and can cause irritation, inconvenience, self-consciousness and fear of social embarrassment. Our objective was to review and appraise literature identified from the MEDLINE and EMBASE databases to evaluate the clinical evidence and provide an update on the risks and benefits of using the levonorgestrel-releasing intrauterine system (LNG-IUS) in the treatment of HMB.The LNG-IUS consistently reduces menstrual blood loss (MBL) in women with HMB, including those with underlying uterine pathology or bleeding disorders. The available data suggest that it reduces MBL to a greater extent than other medical therapies, including combined oral contraceptives, oral progestogens (both short-or long-cycle regimens), tranexamic acid and oral mefenamic acid. In addition, the LNG-IUS and endometrial ablation appear to reduce MBL to a similar extent. The adverse effects reported with the LNG-IUS in women with HMB are similar to those typically observed in women using the system for contraception. Uterine perforations were not reported in any of the studies reviewed, but expulsion rates may be higher than in the general population of LNG-IUS users. Overall, the LNG-IUS has a positive effect on most quality-of-life domains, at least comparable to those achieved with hysterectomy or endometrial ablation, and is consistently a cost-effective option across a variety of countries and settings.In conclusion, the LNG-IUS is an effective treatment option for women with HMB, including those with underlying organic pathology or bleeding disorders. © 2012 Adis Data Information BV. All rights reserved.
Pitts T.,University of Florida
Lung | Year: 2014
Cough and swallow are highly coordinated reflex behaviors whose common purpose is to protect the airway. The pharynx is the common tube for air and food/liquid movement from the mouth into the thorax, has been largely overlooked, and is potentially seen as just a passive space. The thyropharyngeus muscle responds to cough inducing stimuli to prepare a transient holding area for material that has been removed from the subglottic airway. The cricopharyngeus muscle participates with the larynx to ensure regulation of pressure when a bolus/air is moving from the upper airway through to the thorax (i.e., inspiration or swallow) or the reverse (i.e., expiration reflex or vomiting). These vital mechanisms have not been evaluated in clinical conditions but could be impaired in many neurodegenerative diseases, leading to aspiration pneumonia. These newly described airway protective mechanisms need further study, especially in healthy and pathologic human populations. © 2013 Springer Science+Business Media New York.
Johnson J.A.,University of Florida
Pharmacogenomics | Year: 2013
Recent years have seen great advances in our understanding of genetic contributors to drug response. Drug discovery and development around targeted genetic (somatic) mutations has led to a number of new drugs with genetic indications, particularly for the treatment of cancers. Our knowledge of genetic contributors to variable drug response for existing drugs has also expanded dramatically, such that the evidence now supports clinical use of genetic data to guide treatment in some situations, and across a variety of therapeutic areas. Clinical implementation of pharmacogenetics has seen substantial growth in recent years and groups are working to identify the barriers and best practices for pharmacogenetic-guided treatment. The advances and challenges in these areas are described and predictions about future use of genetics in drug therapy are discussed. © 2013 Future Medicine Ltd.
Hollien H.,University of Florida
Journal of Voice | Year: 2014
This article provides a review of data drawn from a series of related experiments to demonstrate how frequency change (Δf0) is accomplished in the modal register. The research cited involves studies of (1) laryngeal size, (2) vocal fold length, (3) vocal fold thickness, and (4) subglottic pressure; new data describe their effect on vocal fold mass. It was found that changes in these dimensions (1) explain how the shifts in frequency are accomplished, (2) establish the way vocal fold mass can be measured, and (3) strongly support the aerodynamic-myoelastic theory of phonation. © 2014 The Voice Foundation.
Van Groenigen K.J.,Northern Arizona University |
Van Groenigen K.J.,Trinity College Dublin |
Qi X.,University of Oklahoma |
Osenberg C.W.,University of Florida |
And 3 more authors.
Science | Year: 2014
Soils contain the largest pool of terrestrial organic carbon (C) and are a major source of atmospheric carbon dioxide (CO2). Thus, they may play a key role in modulating climate change. Rising atmospheric CO2 is expected to stimulate plant growth and soil C input but may also alter microbial decomposition. The combined effect of these responses on long-term C storage is unclear. Combining meta-analysis with data assimilation, we show that atmospheric CO2 enrichment stimulates both the input (+19.8%) and the turnover of C in soil (+16.5%). The increase in soil C turnover with rising CO2 leads to lower equilibrium soil C stocks than expected from the rise in soil C input alone, indicating that it is a general mechanism limiting C accumulation in soil.
Senf S.M.,University of Florida
Frontiers in Physiology | Year: 2013
The stress-inducible 70-kDa heat shock protein (HSP70) is a highly conserved protein with diverse intracellular and extracellular functions. In skeletal muscle, HSP70 is rapidly induced in response to both non-damaging and damaging stress stimuli including exercise and acute muscle injuries. This upregulation of HSP70 contributes to the maintenance of muscle fiber integrity and facilitates muscle regeneration and recovery. Conversely, HSP70 expression is decreased during muscle inactivity and aging, and evidence supports the loss of HSP70 as a key mechanism which may drive muscle atrophy, contractile dysfunction and reduced regenerative capacity associated with these conditions. To date, the therapeutic benefit of HSP70 upregulation in skeletal muscle has been established in rodent models of muscle injury, muscle atrophy, modified muscle use, aging, and muscular dystrophy, which highlights HSP70 as a key therapeutic target for the treatment of various conditions which negatively affect skeletal muscle mass and function. This article will review these important findings and provide perspective on the unanswered questions related to HSP70 and skeletal muscle plasticity which require further investigation. © 2013 Senf.
Seaver E.C.,University of Florida
International Journal of Developmental Biology | Year: 2014
Spiralian development is characterized by the conservation of spindle orientation and cell geometry during early cleavage stages, as well as features of the ultimate fates of identifed cells. This complex set of characters is shared by a number of animal lineages including nemerteans, polyclad platyhelminthes, annelids and mollusks. How a similar, highly stereotypical cleavage program can give rise to such diversity of larval and adult forms has intrigued researchers for many years. This review summarizes recent data from polychaete annelids, and highlights both conservation and variation in the cellular and molecular mechanisms that guide the spiral cleavage developmental program. There is a specifc focus on comparisons of fate maps, patterns of cleavage, mechanisms of cell fate specifcation, organizing activity, and differences in molecular patterning. Some of the differences in early development represent intra-clade variation within annelids, and others hint at differences between annelids and other taxa. Because much of the classic work on spiralians has focused on mollusks, these new data from annelids have expanded our knowledge about the evolutionary fexibility in spiralian development and potentially its role in body plan evolution. © 2014 UBC Press.
Teplitski M.,University of Florida |
Mathesius U.,Australian National University |
Rumbaugh K.P.,Texas Tech University Health Sciences Center
Chemical Reviews | Year: 2011
A study was conducted to examine perception and degradation of N-Acyl homoserine lactone quorum sensing signals by mammalian and plant cells. The mammalian microbiome is integral to the healthy physiology of the host. Plants are constantly exposed to bacteria, especially in the rhizosphere, the area immediately surrounding the roots, where plant exudates provide a food source for bacteria and where bacteria colonize the root surface. In the rhizosphere, AHL concentration is affected by adsorption to soil particles, opening of the lactone ring via photocatalyzed oxidation, or alkaline pH of the surrounding soil, as well as breakdown by plant and bacterial enzymes. Eukaryotic and prokaryotic microbes that are a part of normal microbiota associated with plants and some animals can break down AHLs and their degradation products. So far, there is no report of identification of AHL-degrading microbes directly isolated from the commensal microbiota associated with mammals.
Baylis C.,University of Florida
Journals of Gerontology - Series A Biological Sciences and Medical Sciences | Year: 2012
Females develop less age-dependent loss of renal function, which may be in part due to cardiorenal protective effects of estrogens. The impact of androgen level on cardiovascular-renal health is controversial. Estrogen acts through multiple mechanisms, sometimes beneficial, sometimes damaging, which makes it difficult to predict the effect of hormone replacement therapy (HRT) in an aging population. Nitric oxide (NO) deficiency occurs in aging and contributes to age-dependent cardiovascular risk and kidney damage. The increased oxidative stress of aging has effects at multiple sites in the NO biosynthetic pathway to lower NO production/action. Loss of NO together with activated angiotensin promotes some of the decrements in cardiovascular-renal function seen with age, which may be related to actions of the sex steroids. © The Author 2012. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved.
Campero A.,University of Florida
Neurosurgery | Year: 2010
OBJECTIVE: To describe the technical details of a 3-piece orbitozygomatic approach. INTRODUCTION: In a 3-piece orbitozygomatic approach, soft tissue exposure is mostly comparable to the classic frontopterional approach. Osseous resection is a 3-piece operation that consists of first performing anterior and posterior cuts along the zygomatic arch, reflecting it down, attached to the masseter. This is followed by a classic frontotemporosphenoidal craniotomy, and finally, an osteotomy of the orbital rim, roof, and lateral wall of the orbit. RESULTS: When compared with its 1- and 2-piece counterparts, 3-piece orbitozygomatic craniotomy, as described here, is a relatively simple operation and is thus advisable when considering an anterior or middle fossa approach. Brain exposure is wide, whereas cerebral retraction is minimal. We recommend avoiding orbit sectioning as deep as the superior orbital fissure. CONCLUSION: The modifications described herein show the technical features of the 3-piece orbitozygomatic approach, which provides excellent brain exposure with less retraction and a good cosmetic result.
Meert J.G.,University of Florida
Geoscience Frontiers | Year: 2014
The observation is made that there are very strong similarities between the supercontinents Columbia, Rodinia and Pangea. If plate tectonics was operating over the past 2.5 billion years of Earth history, and dominated by extroversion and introversion of ocean basins, it would be unusual for three supercontinents to resemble one another so closely. The term 'strange attractor' is applied to landmasses that form a coherent geometry in all three supercontinents. Baltica, Laurentia and Siberia form a group of 'strange attractors' as do the elements of East Gondwana (India, Australia, Antarctica, Madagascar). The elements of "West Gondwana" are positioned as a slightly looser amalgam of cratonic blocks in all three supercontinents and are referred to as 'spiritual interlopers'. Relatively few landmasses (the South China, North China, Kalahari and perhaps Tarim cratons) are positioned in distinct locations within each of the three supercontinents and these are referred to as 'lonely wanderers'. There may be several explanations for why these supercontinents show such remarkable similarities. One possibility is that modern-style plate tectonics did not begin until the late Neoproterozoic and horizontal motions were restricted and a vertical style of 'lid tectonics' dominated. If motions were limited for most of the Proterozoic, it would explain the remarkable similarities seen in the Columbia and Rodinia supercontinents, but would still require the strange attractors to rift, drift and return to approximately the same geometry within Pangea. A second possibility is that our views of older supercontinents are shaped by well-known connections documented for the most recent supercontinent, Pangea. It is intriguing that three of the four 'lonely wanderers' (Tarim, North China, South China) did not unite until just before, or slightly after the breakup of Pangea. The fourth 'lonely wanderer', the Kalahari (and core Kaapvaal) craton has a somewhat unique Archean-age geology compared to its nearest neighbors in Gondwana, but very similar to that in western Australia.
Rust M.K.,University of California at Riverside |
Su N.-Y.,University of Florida
Annual Review of Entomology | Year: 2012
Social insects have a tremendous economic and social impact on urban communities. The rapid urbanization of the world has dramatically increased the incidence of urban pests. Human commerce has resulted in the spread of urban invasive species worldwide such that various species are now common to many major urban centers. We aim to highlight those social behaviors that can be exploited to control these pests with the minimal use of pesticides. Their cryptic behavior often prohibits the direct treatment of colonies. However, foraging and recruitment are essential aspects of their social behavior and expose workers to traps, baits, and pesticide applications. The advent of new chemistries has revolutionized the pest management strategies used to control them. In recent years, there has been an increased environmental awareness, especially in the urban community. Advances in molecular and microbial agents promise additional tools in developing integrated pest management programs against social insects. © 2012 by Annual Reviews. All rights reserved.
Yoo M.-J.,University of Florida |
Wendel J.F.,Iowa State University
PLoS Genetics | Year: 2014
The single-celled cotton (Gossypium hirsutum) fiber provides an excellent model to investigate how human selection affects phenotypic evolution. To gain insight into the evolutionary genomics of cotton domestication, we conducted comparative transcriptome profiling of developing cotton fibers using RNA-Seq. Analysis of single-celled fiber transcriptomes from four wild and five domesticated accessions from two developmental time points revealed that at least one-third and likely one-half of the genes in the genome are expressed at any one stage during cotton fiber development. Among these, ~5,000 genes are differentially expressed during primary and secondary cell wall synthesis between wild and domesticated cottons, with a biased distribution among chromosomes. Transcriptome data implicate a number of biological processes affected by human selection, and suggest that the domestication process has prolonged the duration of fiber elongation in modern cultivated forms. Functional analysis suggested that wild cottons allocate greater resources to stress response pathways, while domestication led to reprogrammed resource allocation toward increased fiber growth, possibly through modulating stress-response networks. This first global transcriptomic analysis using multiple accessions of wild and domesticated cottons is an important step toward a more comprehensive systems perspective on cotton fiber evolution. The understanding that human selection over the past 5,000+ years has dramatically re-wired the cotton fiber transcriptome sets the stage for a deeper understanding of the genetic architecture underlying cotton fiber synthesis and phenotypic evolution. © 2014 Wendel, Yoo.
Avena N.M.,University of Florida
Appetite | Year: 2010
This review summarizes evidence of " food addiction" using animal models of binge eating. In our model of sucrose bingeing, behavioral components of addiction are demonstrated and related to neurochemical changes that also occur with addictive drugs. Evidence supports the hypothesis that rats can become dependent and " addicted" to sucrose. Results obtained when animals binge on other palatable foods, including a fat-rich food, are described and suggest that increased body weight can occur. However, the characterization of an addiction-like behavioral profile in animals with binge access to fat requires further exploration in order to dissociate the effect of increased body weight from the diet or schedule of feeding. © 2010 Elsevier Ltd.
Ahn A.H.,University of Florida
Current Pain and Headache Reports | Year: 2013
Several lines of evidence affirm a positive role for exercise in the management of migraine. This review highlights the latest research supporting this view, covering not only its epidemiologic aspects but also the pain modulatory systems that are likely to be engaged by exercise. Recent research provides broad and consistent evidence indicating that cardiovascular exercise can activate multiple pain modulatory mechanisms, if not the underlying mechanisms that initiate the attack. Specifically, a synthesis of independent lines of recent research would indicate that exercise activates endogenous neurotransmitter signals that could be effective in reducing the intensity of migraine pain, though it may not have a direct effect on its overall frequency or duration. © 2013 Springer Science+Business Media New York.
Adler L.S.,University of Massachusetts Amherst |
Seifert M.G.,University of Florida |
Wink M.,University of Heidelberg |
Morse G.E.,University of San Diego
Ecology Letters | Year: 2012
Defensive traits are typically studied in the context of avoiding antagonists, but may also mediate key interactions with mutualists. Plant chemical defences occur in flowers, suggesting pollinators may be agents of selection on defence. We hypothesised that floral defences would deter pollinators, and therefore, pollinators would select for lower defences in outcrossing than self-pollinating species. We measured pollinator reliance and alkaloid levels in 32 greenhouse-grown Nicotiana species. Using a comparative phylogenetic approach, we found significantly lower nectar, floral and leaf nicotine concentrations in outcrossing than selfing species, with a 15-fold decrease in leaf nicotine levels. Nicotine concentrations were positively correlated across tissues, suggesting that selection against floral defences could constrain the evolution of leaf defences. Thus, pollinators could shape the evolution not only of floral defences but also of defences in other tissues where herbivores have traditionally been considered the dominant agent of selection. © 2012 Blackwell Publishing Ltd/CNRS.
Hamlin J.J.,University of Florida
Physica C: Superconductivity and its Applications | Year: 2015
Although the highest superconducting critical temperature, Tc, found in an elemental solid at ambient pressure is 9.2 K (niobium), under the application of ultra-high pressures, several elements exhibit Tc values near or above 20 K. This review includes a survey of the occurrence and understanding of pressure-induced superconductivity in the subset of elements that are metallic at ambient pressure. A particular focus is directed towards those elements that display the highest superconducting critical temperatures or exhibit substantial increases in Tc with pressure. A separate article in this issue by Shimizu will cover pressure-induced superconductivity in elements that are insulating at ambient pressure. © 2015 Elsevier B.V.All rights reserved.
Liu X.,University of Florida
Blood | Year: 2013
Protein kinase R (PKR) is an interferon (IFN)-inducible, double-stranded RNA-activated kinase that initiates apoptosis in response to cellular stress. To determine the role of PKR in hematopoiesis, we developed transgenic mouse models that express either human PKR (TgPKR) or a dominant-negative PKR (TgDNPKR) mutant specifically in hematopoietic tissues. Significantly, peripheral blood counts from TgPKR mice decrease with age in association with dysplastic marrow changes. TgPKR mice have reduced colony-forming capacity and the colonies also are more sensitive to hematopoietic stresses. Furthermore, TgPKR mice have fewer hematopoietic stem/progenitor cells (HSPCs), and the percentage of quiescent (G0) HSPCs is increased. Importantly, treatment of TgPKR bone marrow (BM) with a PKR inhibitor specifically rescues sensitivity to growth factor deprivation. In contrast, marrow from PKR knockout (PKRKO) mice has increased potential for colony formation and HSPCs are more actively proliferating and resistant to stress. Significantly, TgPKR HSPCs have increased expression of p21 and IFN regulatory factor, whereas cells from PKRKO mice display mechanisms indicative of proliferation such as reduced eukaryotic initiation factor 2α phosphorylation, increased extracellular signal-regulated protein kinases 1 and 2 phosphorylation, and increased CDK2 expression. Collectively, data reveal that PKR is an unrecognized but important regulator of HSPC cell fate and may play a role in the pathogenesis of BM failure.
Hoy M.A.,University of Florida
Experimental and Applied Acarology | Year: 2012
Information is provided on the steps involved in classical biological control programs, with an outline of the steps achieved in the classical biological control of the red palm mite, Raoiella indica (Acari: Tenuipalpidae), in Florida. An overview is provided of the results and an accompanying paper by Bowman and Hoy (2012) describes the molecular analyses conducted to characterize phytoseiid predators of the red palm mite collected from Mauritius. The Mauritius phytoseiids were identified as Amblyseius largoensis, using morphological criteria, and compared to four populations of A. largoensis from Florida. The difficulties encountered in the systematics, rearing, and evaluation of the Mauritius phytoseiids are described. A method was tested for obtaining DNA from single mites without destroying the body so that voucher specimens can be maintained. Ultimately, the project was terminated due to constraints expected in obtaining permission to make releases. © 2012 Springer Science+Business Media B.V.
Islam S.,University of Florida
Current Opinion in Pediatrics | Year: 2015
Purpose of review Gastroparesis is a disorder with delayed gastric emptying in the absence of mechanical obstruction. It is one of the more common dysmotilities that occur in the gastrointestinal tract, and is thought to primarily affect adults. Pediatric cases of gastroparesis were considered rare; however, recent evidence suggests growing recognition in children and adolescents. Therefore, it is important for the pediatric caregiver to understand the condition and the treatment options available. Recent findings The majority of patients are women, and presentation is usually with symptoms of persistent nausea, emesis, postprandial pain and bloating, and early satiety. Weight loss may occur in some cases, though this is not universal. The majority of cases are idiopathic, with diabetes mellitus the second most common cause. Summary Treatment consists of symptomatic relief with medication to counteract the nausea, emesis, pain, bloating, gastroesophageal reflux, early satiety, and improve gastric emptying. Dietary modification is also used with small meals and avoidance of high fiber and fat-containing foods. Recalcitrant cases of gastroparesis require the use of additional approaches such as jejunal feeds, intrapyloric botulinum toxin, gastric emptying procedures such as pyloroplasty, and gastric electrical stimulation. We will review these options in this article. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Sinnott S.B.,University of Florida |
Brenner D.W.,North Carolina State University
MRS Bulletin | Year: 2012
A brief history of atomic simulation as it was used in chemistry, physics, and materials science is presented starting with seminal work by Eyring in the 1930s through to current work and future challenges. This article provides the background and perspective needed to understand the ways in which reactive many-body potentials developed over the last three decades and have impacted materials research. It also explains the way in which this substantial impact on the field has been facilitated by increases in computational resources and traces the development of reactive potentials, which have steadily increased in complexity and sophistication over time. Together with the other contributions in this issue of MRS Bulletin, this article will help guide and inspire the next generation of computational materials scientists and engineers as they build on current capabilities to expand atomic simulation into new and exciting areas of materials research. © 2012 Materials Research Society.
Scheuer D.A.,University of Florida
Experimental Physiology | Year: 2010
Chronic stress causes elevations in glucocorticoid secretion and also increases the incidence of hypertension and other manifestations of cardiovascular disease. The extent to which the elevated glucocorticoids mediate the stress-associated increase in cardiovascular disease risk is unknown. Chronically elevated glucocorticoids can cause hypertension by acting in the periphery, but their effects within the brain on blood pressure regulation remain largely unexplored. We developed a method to produce selective chronic increases in the endogenous glucocorticoid corticosterone or the glucocorticoid receptor antagonist mifepristone within the hindbrain region, which includes a key cardiovascular regulatory area, the nucleus of the solitary tract (NTS). Experiments were performed in male Sprague-Dawley, Wistar-Kyoto (WKY) and borderline hypertensive rats (BHR). The results indicate that elevated exogenous corticosterone can act within the hindbrain to enhance the arterial pressure response to novel restraint stress and to reduce the gain and increase the mid-point of the arterial baroreflex. Basal levels of endogenous corticosterone have no effect on the arterial pressure response to stress in normotensive rats but enhance this response in BHR. Chronic stress-induced increases in baseline corticosterone enhance the arterial pressure response to stress in BHR but attenuate the adaptation of the response in WKY rats. Furthermore, an elevated corticosterone concentration within the hindbrain is necessary but not sufficient to cause glucocorticoid-induced hypertension. The effects of corticosterone within the hindbrain on blood pressure regulation are mediated in part by the glucocortiocid receptor, but are also likely to involve mineralocorticoid receptor-mediated effects and NTS catecholaminergic neurons. These data support the hypothesis that elevated glucocorticoids acting within the brain probably contribute to the adverse effects of stress on cardiovascular health in susceptible people. © 2010 The Physiological Society.
Atkinson M.A.,University of Florida |
Chervonsky A.,University of Chicago
Diabetologia | Year: 2012
Abstract Despite years of appreciating the potential role of environment to influence the pathogenesis of type 1 diabetes, specific agents or mechanisms serving in such a capacity remain ill defined. This is exceedingly disappointing as the identification of factors capable of modulating the disease, either as triggers or regulators of the autoimmune response underlying type 1 diabetes, would not only provide clues as to why the disorder develops but, in addition, afford opportunities for improved biomarkers of disease activity and the potential to design novel therapeutics capable of disease abatement. Recent improvements in sequencing technologies, combined with increasing appreciation of the role of innate and mucosal immunity in human disease, have stirred strong interest in what is commonly referred to as the 'gut microbiota'. The gut (or intestinal) microbiota is an exceedingly complex microenvironment that is intimately linked with the immune system, including the regulation of immune responses. After evaluating evidence supporting a role for environment in type 1 diabetes, this review will convey current notions for contributions of the gut microbiota to human health and disease, including information gleaned from studies of humans and animal models for this autoimmune disorder. © Springer-Verlag 2012.
Cusi K.,University of Florida
Gastroenterology | Year: 2012
As obesity reaches epidemic proportions, nonalcoholic fatty liver disease (NAFLD) is becoming a frequent cause of patient referral to gastroenterologists. There is a close link between dysfunctional adipose tissue in NAFLD and common conditions such as metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. This review focuses on the pathophysiology of interactions between adipose tissue and target organs in obesity and the resulting clinical implications for the management of nonalcoholic steatohepatitis. The release of fatty acids from dysfunctional and insulin-resistant adipocytes results in lipotoxicity, caused by the accumulation of triglyceride-derived toxic metabolites in ectopic tissues (liver, muscle, pancreatic beta cells) and subsequent activation of inflammatory pathways, cellular dysfunction, and lipoapoptosis. The cross talk between dysfunctional adipocytes and the liver involves multiple cell populations, including macrophages and other immune cells, that in concert promote the development of lipotoxic liver disease, a term that more accurately describes the pathophysiology of nonalcoholic steatohepatitis. At the clinical level, adipose tissue insulin resistance contributes to type 2 diabetes mellitus and cardiovascular disease. Treatments that rescue the liver from lipotoxicity by restoring adipose tissue insulin sensitivity (eg, significant weight loss, exercise, thiazolidinediones) or preventing activation of inflammatory pathways and oxidative stress (ie, vitamin E, thiazolidinediones) hold promise in the treatment of NAFLD, although their long-term safety and efficacy remain to be established. Better understanding of pathways that link dysregulated adipose tissue, metabolic dysfunction, and liver lipotoxicity will result in improvements in the clinical management of these challenging patients. © 2012 AGA Institute.
Yezierski R.P.,University of Florida
Pain Medicine | Year: 2012
Objective. Preclinical studies of pain and aging represent an area of research where considerations of age, strain, gender, and method of behavioral assessment are but some of the challenges that must be addressed. The results of studies related to the impact of age on pain sensitivity have ranged from increased to decreased sensitivity to no change. Examining the design of these studies one discovers that cross-sectional designs using animals of different ages have been used to evaluate age-related effects in normal animals as well as animals with inflammatory and neuropathic pain conditions. In the present review a summary of these studies is presented along with a discussion of potential mechanisms responsible for changes that have been described. Outcome Measures. The dominant method of behavioral assessment in the majority of studies involving rodents has been reflex-based strategies that unfortunately do not reveal the same effects of experimental manipulations known to affect pain sensitivity in humans. A comparison of results obtained with reflex-based methods versus those obtained with cortically dependent operant methods reveals significant differences. Conclusions. Increases in pain sensitivity under different experimental conditions have been suggested to result from age-related anatomical, physiological, and biochemical changes as well as compensatory changes in homeostatic mechanisms and intrinsic plasticity of somatosensory pathways involved in the processing and perception of pain. Other factors that may contribute to the impact of age on pain sensitivity include dysregulation of the hypothalamic-pituitary-adrenal axis and changes in autonomic function that occur with advancing age. In the future translational research in the field of pain and aging will need to focus on establishing clinically relevant animal models and assessment strategies to evaluate the causal relationships between the biological changes associated with advancing age and the varied behavioral changes in pain sensitivity. © 2012.
Cottler L.B.,University of Florida
Science translational medicine | Year: 2012
The August 2011 Clinical and Translational Science Awards conference "Using IT to Improve Community Health: How Health Care Reform Supports Innovation" convened four "Think Tank" sessions. This report summarizes the content of one session centered on "Social Networking: Community Connections and Health Outcomes." We discuss the efforts of HealthStreet to facilitate ongoing, real-time assessment of community health needs, concerns, and opportunities to participate in research.
Baylis C.,University of Florida
Current Opinion in Nephrology and Hypertension | Year: 2012
Purpose of Review: Nitric oxide deficiency occurs by multiple mechanisms and contributes to the pathogenesis of progression of chronic kidney disease (CKD) and its cardiovascular complications. This article concentrates on recent developments on the regulation of the endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) in CKD and on the importance of the nitric oxide synthases in kidney disease progression, particularly in diabetic nephropathy. RECENT FINDINGS: The increased plasma ADMA seen in renal disease is generally predictive of severity of CKD progression and cardiovascular risk. However, some assumptions about the control of ADMA have been challenged: the primacy of the kidney as a metabolic organ for plasma ADMA regulation has come under scrutiny and the relative importance of the two isoforms of the ADMA-metabolizing enzymes dimethylarginine dimethylaminohydrolases (DDAHs) is being re-evaluated. Alterations in NOS also contribute to CKD progression with the endothelial isoform playing a major role in diabetic nephropathy. Summary: Improving our understanding of ADMA regulation is important since pharmacologic targeting of DDAH is underway. The major role of endothelial NOS-derived nitric oxide in diabetic nephropathy should lead to novel therapies. The beneficial actions of dietary nitrate supplementation on blood pressure and kidney disease are of considerable clinical relevance. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Gerber S.,University of Florida |
Jack Brookshire E.N.,Montana State University
American Naturalist | Year: 2014
Nutrient limitation in terrestrial ecosystems is often accompanied with maintaining a nearly closed vegetation-soil nutrient cycle. The ability to retain nutrients in an ecosystem requires the capacity of the plant-soil system to draw down nutrient levels in soils effectually such that export concentrations in soil solutions remain low. Here we address the physical constraints of plant nutrient uptake that may be limited by the diffusive movement of nutrients in soils, by the uptake at the root/mycorrhizal surface, and from interactions with soil water flow. We derive an analytical framework of soil nutrient transport and uptake and predict levels of plant available nutrient concentration and residence time. Our results, which we evaluate for nitrogen, show that the physical environment permits plants to lower soil solute concentration substantially. Our analysis confirms that plant uptake capacities in soils are considerable, such that water movement in soils is generally too small to significantly erode dissolved plant-available nitrogen. Inorganic nitrogen concentrations in headwater streams are congruent with the prediction of our theoretical framework. Our framework offers a physical-based parameterization of nutrient uptake in ecosystem models and has the potential to serve as an important tool toward scaling biogeochemical cycles from individual roots to landscapes. © 2014 by The University of Chicago.
Christou E.A.,University of Florida
Exercise and Sport Sciences Reviews | Year: 2011
Older adults exhibit greater motor variability, which impairs their accuracy and function, compared with young adults. Low-intensity training that emphasizes muscle coordination reduces variability in older adults. Furthermore, a low amount of visual feedback minimizes age-associated differences in variability. We hypothesize that an intervention that combines muscle coordination and reduced visual feedback would be advantageous to improve motor control in older adults. © 2011 The Amercian College of Sports Medicine.
Gil M.A.,University of Florida
Ecology | Year: 2013
The magnitude and direction of biological effects of environmental disturbances can vary considerably, especially among studies that use presence/absence manipulations. Because nonlinearities (e.g., humped relationships) are common in biological systems, this heterogeneity in effects may arise if systems are similar in their responses but specific studies use few (e.g., two) levels, or a narrow range, of a factor. To test whether nonlinearity can explain heterogeneous responses to a common environmental disturbance, I examined the effect of nutrient enrichment on coral growth, which has been previously shown using simple (e.g., two-level) manipulations to yield positive, negative, or neutral responses. I subjected corals (Porites) to a nutrient gradient in situ for 28 days. Coral growth rate increased (2.4-fold) then decreased (2.7-fold) with enrichment, returning to near-ambient values at the highest nutrient levels. This unimodal response could explain disparities among past findings and provides a compelling case for using regression designs to understand heterogeneity within ecological interactions. © 2013 by the Ecological Society of America.
Tabachnick W.J.,University of Florida
Journal of Experimental Biology | Year: 2010
Vector-borne pathogens cause enormous suffering to humans and animals. Many are expanding their range into new areas. Dengue, West Nile and Chikungunya have recently caused substantial human epidemics. Arthropod-borne animal diseases like Bluetongue, Rift Valley fever and African horse sickness pose substantial threats to livestock economies around the world. Climate change can impact the vector-borne disease epidemiology. Changes in climate will influence arthropod vectors, their life cycles and life histories, resulting in changes in both vector and pathogen distribution and changes in the ability of arthropods to transmit pathogens. Climate can affect the way pathogens interact with both the arthropod vector and the human or animal host. Predicting and mitigating the effects of future changes in the environment like climate change on the complex arthropod-pathogen-host epidemiological cycle requires understanding of a variety of complex mechanisms from the molecular to the population level. Although there has been substantial progress on many fronts the challenges to effectively understand and mitigate the impact of potential changes in the environment on vector-borne pathogens are formidable and at an early stage of development. The challenges will be explored using several arthropod-borne pathogen systems as illustration and potential avenues to meet the challenges will be presented. © 2010, Published by The Company of Biologists Ltd.
Shirley M.H.,Ziegler |
Shirley M.H.,University of Florida
Proceedings. Biological sciences / The Royal Society | Year: 2014
Accurate species delimitation is a central assumption of biology that, in groups such as the Crocodylia, is often hindered by highly conserved morphology and frequent introgression. In Africa, crocodilian systematics has been hampered by complex regional biogeography and confounded taxonomic history. We used rigorous molecular and morphological species delimitation methods to test the hypothesis that the slender-snouted crocodile (Mecistops cataphractus) is composed of multiple species corresponding to the Congolian and Guinean biogeographic zones. Speciation probability was assessed by using 11 mitochondrial and nuclear genes, and cranial morphology for over 100 specimens, representing the full geographical extent of the species distribution. Molecular Bayesian and phylogenetic species delimitation showed unanimous support for two Mecistops species isolated to the Upper Guinean and Congo (including Lower Guinean) biomes that were supported by 13 cranial characters capable of unambiguously diagnosing each species. Fossil-calibrated phylogenetic reconstruction estimated that the species split ± 6.5-7.5 Ma, which is congruent with intraspecies divergence within the sympatric crocodile genus Osteolaemus and the formation of the Cameroon Volcanic Line. Our results underscore the necessity of comprehensive phylogeographic analyses within currently recognized taxa to detect cryptic species within the Crocodylia. We recommend that the community of crocodilian researchers reconsider the conceptualization of crocodilian species especially in the light of the conservation ramifications for this economically and ecologically important group.
Chouvenc T.,University of Florida
Proceedings. Biological sciences / The Royal Society | Year: 2013
Social insects nesting in soil environments are in constant contact with entomopathogens but have evolved a range of defence mechanisms, resulting in both individual and social immunity that reduce the chance for epizootics in the colony, as in the case of subterranean termites. Coptotermes formosanus uses its faeces as building material for its nest structure that result into a 'carton material', and here, we report that the faecal nest supports the growth of Actinobacteria which provide another level of protection to the social group against entomopathogens. A Streptomyces species with in vivo antimicrobial activity against fungal entomopathogens was isolated from the nest material of multiple termite colonies. Termite groups were exposed to Metarhizium anisopliae, a fungal entomopathogen, during their foraging activity and the presence of Streptomyces within the nest structure provided a significant survival benefit to the termites. Therefore, this report describes a non-nutritional exosymbiosis in a termite, in the form of a defensive mutualism which has emerged from the use of faecal material in the nesting structure of Coptotermes. The association with an Actinobacteria community in the termite faecal material provides an extended disease resistance to the termite group as another level of defence, in addition to their individual and social immunity.
Eruslanov E.,University of Florida
International immunopharmacology | Year: 2011
Bladder cancer is associated with enhanced inflammation and characterized by deregulated prostanoid metabolism. Here we examined prostaglandin E (PGE) metabolism and myeloid cell subsets that infiltrate tumor tissue using two xenograft models of human bladder cancer. Human bladder tumor xenografts implanted into athymic nude mice become highly infiltrated with host CD11b myeloid cells of bone marrow origin. Fast growing SW780 bladder tumor xenografts were infiltrated with heterogeneous CD11b myeloid cell subsets including tumor-associated macrophages and myeloid-derived suppressor cells. In contrast, majority of myeloid cells in tumor tissue from slow growing bladder cancer Urothel 11 displayed more immature, homogenous phenotype and comprised mostly MHC II class-negative myeloid-derived suppressor cells. We demonstrate that human bladder tumors secrete substantial amounts of PGE. Normal bone marrow myeloid cell progenitors cultured in the presence of a bladder tumor-conditioned medium, which is enriched for PGE, failed to differentiate into mature APCs and acquired phenotype of the myeloid-derived suppressor cells or inflammatory macrophages with up-regulated chemokine receptor CXCR4. Collectively our data demonstrate that enhanced cancer-related inflammation and deregulated PGE metabolism in tumor microenvironment promote immunosuppressive pro-tumoral phenotype of myeloid cells in bladder cancer. These data also suggest that not only local tumor microenvironment but other factors such as stage of cancer disease and pace of tumor growth could markedly influence the phenotype, differentiation and immune function of myeloid cells in tumor tissue. Copyright © 2011 Elsevier B.V. All rights reserved.
Lan G.,University of Florida
Mathematical Programming | Year: 2013
The main goal of this paper is to develop uniformly optimal first-order methods for convex programming (CP). By uniform optimality we mean that the first-order methods themselves do not require the input of any problem parameters, but can still achieve the best possible iteration complexity bounds. By incorporating a multi-step acceleration scheme into the well-known bundle-level method, we develop an accelerated bundle-level method, and show that it can achieve the optimal complexity for solving a general class of black-box CP problems without requiring the input of any smoothness information, such as, whether the problem is smooth, nonsmooth or weakly smooth, as well as the specific values of Lipschitz constant and smoothness level. We then develop a more practical, restricted memory version of this method, namely the accelerated prox-level (APL) method. We investigate the generalization of the APL method for solving certain composite CP problems and an important class of saddle-point problems recently studied by Nesterov (Math Program 103:127–152, 2005). We present promising numerical results for these new bundle-level methods applied to solve certain classes of semidefinite programming and stochastic programming problems. © 2013, Springer-Verlag Berlin Heidelberg and Mathematical Optimization Society.
Salois M.J.,University of Florida
Physica A: Statistical Mechanics and its Applications | Year: 2013
Foreign aid contributes significantly to the income levels and economic viability of many developing countries. This paper investigates the dispersion in the distribution of foreign aid using the Theil entropy measure of inequality. Results show that the inequality (dispersion) of foreign aid has increased substantially in recent years. The increased inequality in the total distribution of aid has been due to both increases in the regional inequality of aid and increases in the average inequality of aid within each region. As a result, the distribution of aid is becoming less alike between regions and between countries within regions. © 2013 Elsevier B.V. All rights reserved.
Jeong K.C.,University of Florida |
Sexton J.A.,University of California at Santa Barbara |
Vogel J.P.,University of Washington
PLoS Pathogens | Year: 2015
Modulation of host cell function is vital for intracellular pathogens to survive and replicate within host cells. Most commonly, these pathogens utilize specialized secretion systems to inject substrates (also called effector proteins) that function as toxins within host cells. Since it would be detrimental for an intracellular pathogen to immediately kill its host cell, it is essential that secreted toxins be inactivated or degraded after they have served their purpose. The pathogen Legionella pneumophila represents an ideal system to study interactions between toxins as it survives within host cells for approximately a day and its Dot/Icm type IVB secretion system (T4SS) injects a vast number of toxins. Previously we reported that the Dot/Icm substrates SidE, SdeA, SdeB, and SdeC (known as the SidE family of effectors) are secreted into host cells, where they localize to the cytoplasmic face of the Legionella containing vacuole (LCV) in the early stages of infection. SidJ, another effector that is unrelated to the SidE family, is also encoded in the sdeC-sdeA locus. Interestingly, while over-expression of SidE family proteins in a wild type Legionella strain has no effect, we found that their over-expression in a ∆sidJ mutant completely inhibits intracellular growth of the strain. In addition, we found expression of SidE proteins is toxic in both yeast and mammalian HEK293 cells, but this toxicity can be suppressed by co-expression of SidJ, suggesting that SidJ may modulate the function of SidE family proteins. Finally, we were able to demonstrate both in vivo and in vitro that SidJ acts on SidE proteins to mediate their disappearance from the LCV, thereby preventing lethal intoxication of host cells. Based on these findings, we propose that SidJ acts as a metaeffector to control the activity of other Legionella effectors. © 2015 Jeong et al.
Johnson J.A.,University of Florida
Annals of Medicine | Year: 2012
Hypertension is the most common, chronic disease in the world, and there are many effective pharmacological agents available for its treatment. Despite the plethora of treatment options, data across the globe suggest that blood pressure control rates are < 50%, a fact likely influenced in part by the inability to predict the antihypertensive drug likely to be most effective for an individual patient. Pharmacogenomics in hypertension holds the promise of identifying genetic biomarkers for antihypertensive drug response, which might be used in the future in treatment selection. Research in the field is also likely to enhance our understanding of hypertension and the mechanisms by which the various drugs produce efficacy. There are several examples in the literature of genes with relatively strong data on associations of genetic polymorphisms with antihypertensive response; the data on ADRB1, CACNB2, and NEDD4L are detailed as examples. Substantial additional data in hypertension pharmacogenomics are expected to be forthcoming from recently completed genome-wide association studies. Increased collaboration among research groups will help insure successful discoveries from these large-scale studies. The next decade should clearly define the potential clinical implications of the research in hypertension pharmacogenomics that is currently in progress. © 2012 Informa UK, Ltd.
Garrott R.A.,Montana State University |
Oli M.K.,University of Florida
Science | Year: 2013
Captive wild horses will cost the United States over $1 billion by 2030 unless management approaches change.
Ingwersen W.W.,University of Florida
Ecological Modelling | Year: 2010
While statistical estimation of uncertainty has not typically accompanied published emergy values, as with any other quantitative model, uncertainty is embedded in these values, and lack of uncertainty characterization makes their accuracy not only opaque, it also prevents the use of emergy values in statistical tests of hypotheses. This paper first attempts to describe sources of uncertainty in unit emergy values (UEVs) and presents a framework for estimating this uncertainty