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The University of Manitoba is a public university in the province of Manitoba, Canada. Located in Winnipeg, it is a research-intensive post-secondary educational institution. Founded in 1877, it was Western Canada’s first university. Wikipedia.

Apalkov V.M.,Georgia State University | Chakraborty T.,University of Manitoba
Physical Review Letters | Year: 2010

Here we report from our theoretical studies that, in biased bilayer graphene, one can induce phase transitions from an incompressible fractional quantum Hall state to a compressible state by tuning the band gap at a given electron density. The nature of such phase transitions is different for weak and strong interlayer coupling. Although for strong coupling more levels interact there is a lesser number of transitions than for the weak coupling case. The intriguing scenario of tunable phase transitions in the fractional quantum Hall states is unique to bilayer graphene and has never before existed in conventional semiconductor systems. © 2010 The American Physical Society.

Hernandez-Trujillo V.,Director | Simons F.E.R.,University of Manitoba
Journal of Allergy and Clinical Immunology: In Practice | Year: 2013

Background: Few anaphylaxis education materials have been prospectively evaluated in randomized controlled trials. Objective: Our objective was to evaluate the American Academy of Allergy, Asthma & Immunology Anaphylaxis Wallet Card (AAAAI-AWC) as an anaphylaxis education mini-handout for health care professionals. Methods: We performed a randomized controlled study of the AAAAI-AWC with residents in general pediatrics at Miami Children's Hospital. Participants in the intervention group completed a pretest about anaphylaxis, heard a 3-minute PowerPoint presentation based on the AAAAI-AWC, reviewed the AAAAI-AWC, and discussed it with the presenter. After this, participants took a post-test immediately and a follow-up test 4 weeks later. Participants in the control group took the pretest, were handed an AAAAI-AWC, studied it briefly, then took the post-test immediately and the follow-up test 4 weeks later. Results: Fifty-five residents participated. Regardless of the amount of time spent studying the AAAAI-AWC, when the pretests were compared with the post-tests and follow-up tests, residents in both the intervention and control groups were more likely to recognize anaphylaxis symptoms (P < .05), name asthma as the most common comorbid disease in children with fatal or near-fatal anaphylaxis (P < .05), and recall the names of epinephrine auto injectors (P < .05) and the epinephrine doses available in these auto injectors (P < .05). When the pretests were compared with the post-tests and the follow-up tests, residents in the intervention group were more likely than controls to identify the body organ systems involved in severe or fatal anaphylaxis correctly (P < .05). Conclusion: The AAAAI-AWC is a practical, concise anaphylaxis education mini-handout for pediatric residents, a time-challenged group of health care professionals. © 2013 American Academy of Allergy, Asthma & Immunology.

Nicolle L.E.,University of Manitoba
Drugs and Aging | Year: 2014

From 5-10 % of elderly residents of long-term care facilities require chronic indwelling catheters for management of urine voiding. These residents are always bacteriuric, because of biofilm formation along the catheter, and experience increased morbidity associated with urinary tract infection. A wide variety of bacteria or yeast species are isolated. Occasional episodes of symptomatic infection may be accompanied by localizing genitourinary findings. However, when fever is present and there are no localizing findings, symptomatic infection is a diagnosis of exclusion. Many of these episodes are not from a urinary source, so critical clinical evaluation is always necessary. A urine specimen for culture should be obtained from patients with symptomatic infection prior to institution of antimicrobial therapy. When the catheter has been present for 2 weeks or longer, it should be replaced and the urine specimen collected through the new catheter. This provides a specimen of bladder urine without biofilm contamination, and catheter replacement also improves clinical outcomes. Treatment algorithms with a goal of limiting inappropriate treatment of asymptomatic bacteriuria have been developed. Empiric antimicrobial therapy should be avoided when possible. Guidelines for prevention of catheteracquired urinary infection should be followed. The most important of these is to avoid use of a urinary catheter whenever possible and, when there is no longer an indication for the catheter, to remove it promptly © Springer International Publishing Switzerland 2013.

Zhang Y.,Nanyang Technological University | Niyato D.,Nanyang Technological University | Wang P.,Huazhong University of Science and Technology | Hossain E.,University of Manitoba
IEEE Communications Magazine | Year: 2012

Auction theory, as a subfield of economics, provides useful tools to model, analyze, and optimize radio resource management in cognitive radio environments. By using an auction, radio resources such as subchannel, time slot, and transmit power can be allocated among licensed and unlicensed users in the system, following market laws. Due to the flexibility of mechanism design, there are various auction mechanisms that have been applied to cognitive radio systems with different characteristics. In this article, we first provide an overview of the basics of general auctions. Then the motivations and specific design issues in applying auctions to wireless network architectures and protocols are discussed. Then we review the state of the art in the use of auction theory and mechanism design in cognitive radio networks. This will enable the readers to have a general view of auction fundamentals, as well as the recent development and applications of auction theory in the emerging cognitive wireless networks. © 2012 IEEE.

We explore perpendicular diffusion based on the unified nonlinear transport theory. In Paper I, we focused on magnetostatic turbulence, whereas in the present article we include dynamical turbulence effects. For simplicity, we assume a constant correlation time. We show that there is now a nonvanishing contribution of the slab modes. We explore the parameter regimes in which the turbulence dynamics becomes important for perpendicular diffusion. Analytical forms for the perpendicular diffusion coefficient are derived, which can be implemented easily in solar modulation or shock acceleration codes. © 2014. The American Astronomical Society. All rights reserved.

Smil V.,University of Manitoba
Annals of the Association of American Geographers | Year: 2011

Burdensome dependence on crude oil imports is a key challenge for America's energy policy; its principal cause is excessive consumption of refined oil products, which is mainly the result of an inefficient automotive fleet, the virtual absence of diesel-powered cars, and the complete absence of modern high-velocity trains. Addressing these challenges will require major infrastructural investment, a reality that precludes any early attainment of energy independence. © 2011 by Association of American Geographers.

Hossain E.,University of Manitoba
IEEE Wireless Communications | Year: 2012

Recently, network coding has emerged as a new cooperative technique for improving network throughputs over traditional routing techniques. Network coding allows intermediate nodes to combine packets using an algebraic function before forwarding. Selfless cooperation by the intermediate nodes is thus implicitly assumed in the network employing network coding. Such cooperation in principle should not happen for free but for mutual benefits shared by source-destination pairs and the cooperating intermediate nodes. Effective resource allocation techniques are thus required to efficiently utilize the limited network resources at the intermediate nodes. In this article, we propose one such effective buffer allocation algorithm, called buffer equalized opportunistic network coding (BE-ONC), to dynamically exploit buffer spaces at a relay node of a relay-based IEEE 802.11 network. The BE-ONC technique combines packets opportunistically based on dynamic buffer allocation at the relay. Through simulations, we illustrate that the proposed scheme improves over the classical packet scheduling schemes in terms of delay and successful packet delivery ratio in a cooperative relay-based Wi-Fi network. Our experimental results further confirm the potential benefits of BE-ONC in terms of packet delivery ratio, when compared with first-in first-out scheduling at the relay node. The guidelines for extending our proposed scheme to a more general scenario, where more than two users are involved, and the relay is allowed to transmit its own packet, are also provided. © 2002-2012 IEEE.

Gao Z.,University of Manitoba
International Journal of Advanced Manufacturing Technology | Year: 2012

Two-dimensional thermal elasto-plastic model was established by finite element method to investigate weld heat-affected zone (HAZ) liquation cracking behavior during laser and laser-gas metal arc (GMA) hybrid welding nickel-based superalloy. Transient temperature, cooling rate, and stress and strain history were used and combined with solidification theory to analyze the mechanism of liquation cracking in the HAZ. Weld cracking mechanical driving force is related to local stress-strain development at the period of solidification, and stress and strain components were correlated along the fusion boundary of weld pool. Strain rate and weld pool geometry were demonstrated during in the stage of solidification process, which provide valuable insight into the quantitative evaluation the tendency of solidification cracking and give well understanding why laser-GMA welding is beneficial for minimizing cracking susceptibility than laser welding. © 2012 Springer-Verlag London Limited.

Martens P.J.,Manitoba Center for Health Policy | Chochinov H.M.,University of Manitoba | Prior H.J.,Manitoba Center for Health Policy
Journal of Clinical Psychiatry | Year: 2014

Objective: To compare the causes and rates of death for people with and without schizophrenia in Manitoba, Canada. Method: Using de-identified administrative databases at the Manitoba Centre for Health Policy, a population-based analysis was performed to compare age- and sex-adjusted 10-year (1999-2008) mortality rates, overall and by specific cause, of decedents aged 10 years or older who had 1 diagnosis of schizophrenia (ICD-9-CM code 295, ICD-10-CA codes F20, F21, F23.2, F25) over a 12-year period (N=9,038) to the rest of the population (N=969,090). Results: The mortality rate for those with schizophrenia was double that of the rest of the population (20.00% vs 9.37%). The all-cause mortality rate was higher for people with schizophrenia compared to all others (168.9 vs 99.1 per thousand; relative risk [RR]=1.70, P<.0001); rates of death due to suicide (RR=8.67, P<.0001), injury (RR=2.35, P<.0001), respiratory illness (RR=2.00, P<.0001), and circulatory illness (RR=1.64, P<.0001) were also significantly higher in people with schizophrenia. Overall cancer deaths were similar (28.6 vs 27.3 per thousand, P=.42, NS) except in the middle-aged group (40-59), in which cancer death rates were significantly higher for those with schizophrenia (28.7 vs 11.6 per thousand; RR=2.48, P<.01). Mortality rates due to lung cancer were significantly higher in people with schizophrenia (9.4 vs 6.4 per thousand, RR=1.45, P<.001). Conclusions: People with schizophrenia are at increased risk of death compared to the general population, and the majority of these deaths are occurring in older age from physical disease processes. Risk of cancer mortality is significantly higher in middle-aged but not younger or older patients with schizophrenia. Understanding these patients' vulnerabilities to physical illness has important public health implications for prevention, screening, and treatment as the population ages. © Copyright 2014 Physicians Postgraduate Press, Inc.

Sephton P.,Queens University | Mann J.,University of Manitoba
Energy Economics | Year: 2013

Using a long span of data in Spain, Esteve and Tamarit (2012b) reported evidence of a strong link between per capita income and per capita CO2. In this paper we extend their work, finding evidence of both non-linear cointegration and asymmetric adjustment using a novel approach due to Sephton (1994) and Sephton and Mann (2012). The results suggest that there is a long-run non-linear attractor drawing per capita income and CO2 levels together, with asymmetric adjustment. © 2013 Elsevier B.V.

Simons F.E.R.,University of Manitoba | Schatz M.,Kaiser Permanente
Journal of Allergy and Clinical Immunology | Year: 2012

Anaphylaxis during pregnancy, labor, and delivery can be catastrophic for the mother and, especially, the infant. Symptoms and signs can include intense vulvar and vaginal itching, low back pain, uterine cramps, fetal distress, and preterm labor. During the first 3 trimesters, etiologies are similar to those in nonpregnant women. During labor and delivery, common etiologies are β-lactam antibiotics, natural rubber latex, and other agents used in medical and perioperative settings. Important caveats in management include injecting epinephrine (adrenaline) promptly, providing high-flow supplemental oxygen, positioning the mother on her left side to improve venous return to the heart, maintaining a minimum maternal systolic blood pressure of 90 mm Hg to ensure adequate placental perfusion, and continuous electronic monitoring. Cardiopulmonary resuscitation and emergency cesarean delivery should be performed when indicated. In all women of child-bearing age, allergy/immunology specialists can help to prevent anaphylaxis in pregnancy through prepregnancy risk assessment and risk reduction strategies, such as confirming the etiology of systemic allergic reactions, providing written instructions for allergen avoidance, and initiating relevant immune modulation. In pregnant women the benefits versus risks of skin tests, challenge tests, desensitization, and initiation of immunotherapy with allergens should be carefully weighed; if possible, these procedures should be deferred until after parturition. Prospective interdisciplinary studies of anaphylaxis during pregnancy are needed. © 2012 American Academy of Allergy, Asthma & Immunology.

Shalchi A.,University of Manitoba
Contributions to Plasma Physics | Year: 2011

In the present article previous work is complemented by investigating analytically the field line random walk in partially turbulent magnetic fields. By using the well-established model of two-dimensional turbulence with a general spectrum at large scales, we compute the field line diffusion coefficient for all length scales. This work will also clarify some confusion about the superdiffusive and diffusive regimes discovered earlier. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Teller J.T.,University of Manitoba
Quaternary Research (United States) | Year: 2013

Lake Agassiz was ponded on the northward-sloping surface of the Hudson Bay and Arctic Ocean basins, as the Laurentide Ice Sheet retreated. The level of Lake Agassiz abruptly fell ~12.9cal (1114C) ka BP, exposing the lake floor over a large region for >1000yr. The routing of overflow during this (Moorhead low-water) period is uncertain, and there is evidence on the continent and in ocean basins for both an easterly route through the Great Lakes-St. Lawrence to the North Atlantic and for a northwesterly route through the Clearwater-Athabasca-Mackenzie system to the Arctic Ocean. The Moorhead low water phase coincides with the Younger Dryas cooling, and a cause-effect relationship has been proposed by attributing a change in ocean thermohaline circulation to the re-routing of Lake Agassiz freshwaters from the Gulf of Mexico to more northern oceans. Paleoclimatic interpretations from ecosystems in lake sediments in the region, and a simple calculation of the paleohydrological budget of Lake Agassiz, indicate that the climate remained wet and cool throughout the YD in this region, and was not warm nor dry enough to allow evaporative loss to offset the influx of meltwater and precipitation; thus, the Moorhead phase resulted from changes in the outlet that carried overflow. © 2013 University of Washington.

Luo Y.,University of Manitoba
International Journal for Numerical Methods in Biomedical Engineering | Year: 2010

In this paper, the conventional global univariate Lagrange interpolation method is transformed into a local multivariate interpolation method. The method has the following attractive features: it can be used to interpolate irregularly distributed data points; it does not need to solve local problems; if used for constructing shape functions, the obtained shape functions satisfy the Kronecker delta condition and they have the reproducing properties. The performance of the local multivariate Lagrange interpolation method was examined by applying it to function approximation. Copyright © 2008 John Wiley & Sons, Ltd.

Kirpalani H.,Childrens Hospital of Philadelphia | Kirpalani H.,McMaster University | Millar D.,Royal Maternity Hospital | Lemyre B.,University of Ottawa | And 3 more authors.
New England Journal of Medicine | Year: 2013

BACKGROUND: To reduce the risk of bronchopulmonary dysplasia in extremely-low-birth-weight infants, clinicians attempt to minimize the use of endotracheal intubation by the early introduction of less invasive forms of positive airway pressure. METHODS: We randomly assigned 1009 infants with a birth weight of less than 1000 g and a gestational age of less than 30 weeks to one of two forms of noninvasive respiratory support - nasal intermittent positive-pressure ventilation (IPPV) or nasal continuous positive airway pressure (CPAP) - at the time of the first use of noninvasive respiratory support during the first 28 days of life. The primary outcome was death before 36 weeks of postmenstrual age or survival with bronchopulmonary dysplasia. RESULTS: Of the 497 infants assigned to nasal IPPV for whom adequate data were available, 191 died or survived with bronchopulmonary dysplasia (38.4%), as compared with 180 of 490 infants assigned to nasal CPAP (36.7%) (adjusted odds ratio, 1.09; 95% confidence interval, 0.83 to 1.43; P = 0.56). The frequencies of air leaks and necrotizing enterocolitis, the duration of respiratory support, and the time to full feedings did not differ significantly between treatment groups. CONCLUSIONS: Among extremely-low-birth-weight infants, the rate of survival to 36 weeks of post-menstrual age without bronchopulmonary dysplasia did not differ significantly after noninvasive respiratory support with nasal IPPV as compared with nasal CPAP. Copyright © 2013 Massachusetts Medical Society.

Aluko R.E.,University of Manitoba
Annual Review of Food Science and Technology | Year: 2015

Bioactive peptides are encrypted within the primary structure of food proteins where they remain inactive until released by enzymatic hydrolysis. Once released from the parent protein, certain peptides have the ability to modulate the renin-angiotensin system (RAS) because they decrease activities of renin or angiotensin-converting enzyme (ACE), the two main enzymes that regulate mammalian blood pressure. These antihypertensive peptides can also enhance the endothelial nitric oxide synthase (eNOS) pathway to increase nitric oxide (NO) levels within vascular walls and promote vasodilation. The peptides can block the interactions between angiotensin II (vasoconstrictor) and angiotensin receptors, which can contribute to reduced blood pressure. This review focuses on the methods that are involved in antihypertensive peptide production from food sources, including fractionation protocols that are used to enrich bioactive peptide content and enhance peptide activity. It also discusses mechanisms that are believed to be involved in the antihypertensive activity of these peptides. Copyright ©2015 by Annual Reviews. All rights reserved.

Research on the HIV vulnerability of men who have sex with men (MSM) in India has tended to focus on aggregates of individual risk behaviours. However, such an approach often overlooks the complexities in the sexual networks that ultimately underpin patterns of spread. This paper analyses a set of sexual contact network (SCN) snapshots in relation to ethnographic findings to reorientate individual-level explanations of risk behaviour in terms of more complex systems. Fifteen community researchers conducted a 2-month ethnographic study in three cities in Karnataka to generate descriptions of the risk environments inhabited by MSM. SCNs were reconstructed by two methods. First, initial participants, defined as nodes of various sexual networks, were purposively sampled. In each site, six nodes brought in three sexual partners separately as participants. In all sites, 72 participants completed 431 surveys for their 7-day sexual partners. Second, each site determined four groups representing various sexual networks, each group containing four individuals. In all sites, 48 participants completed 334 surveys for their regular sexual partner. Considerable differences were observed between sites for practically all included behavioural variables. On their own, these characteristics yielded contradictory interpretations with respect to understanding contrasts in HIV prevalence at each site. However, viewing these variables in relation to SCNs and ethnographic data produced non-linear interpretations of HIV vulnerability which suggested importance to local interventions. SCN data may be used with existing data on risk behaviour and the structural determinants of vulnerability to re-tailor more tightly focused interventions.

Cao R.,Fudan University | Deng C.,University of Manitoba
Scripta Materialia | Year: 2015

Here we report the finding that the strongest grain size to achieve the maximum flow stress in nanocrystalline Ni nanowires was significantly smaller (d = 5 nm) than that in typical bulk metals (d > 10 nm). The discrepancy was due to the dominance of plasticity via surface slip in Ni nanowires at relatively large grain sizes, which was absent in bulk materials. An interesting grain size- and temperature-dependent "hardening"-to-"softening" transition in Ni nanowires was also revealed in this study. © 2014 Acta Materialia Inc.

Sharanowski B.J.,University of Manitoba | Dowling A.P.G.,University of Arkansas | Sharkey M.J.,University of Kentucky
Systematic Entomology | Year: 2011

This study examined subfamilial relationships within Braconidae, using 4 kb of sequence data for 139 taxa. Genetic sampling included previously used markers for phylogenetic studies of Braconidae (28S and 18S rDNA) as well as new nuclear protein-coding genes (CAD and ACC). Maximum likelihood and Bayesian inference of the concatenated dataset recovered a robust phylogeny, particularly for early divergences within the family. This study focused primarily on non-cyclostome subfamilies, but the monophyly of the cyclostome complex was strongly supported. There was evidence supporting an independent clade, termed the aphidioid complex, as sister to the cyclostome complex of subfamilies. Maxfischeria was removed from Helconinae and placed within its own subfamily within the aphidioid complex. Most relationships within the cyclostome complex were poorly supported, probably because of lower taxonomic sampling within this group. Similar to other studies, there was strong support for the alysioid subcomplex containing Gnamptodontinae, Alysiinae, Opiinae and Exothecinae. Cenocoeliinae was recovered as sister to all other subfamilies within the euphoroid complex. Planitorus and Mannokeraia, previously placed in Betylobraconinae and Masoninae, respectively, were moved to the Euphorinae, and may share a close affiliation with Neoneurinae. Neoneurinae and Ecnomiinae were placed as tribes within Euphorinae. A sister relationship between the microgastroid and sigalphoid complexes was also recovered. The helconoid complex included a well-supported lineage that is parasitic on lepidopteran larvae (macrocentroid subcomplex). Helconini was raised to subfamily status, and was recovered as sister to the macrocentroid subcomplex. Blacinae was demoted to tribal status and placed within the newly circumscribed subfamily Brachistinae, which also contains the tribes Diospilini, Brulleiini and Brachistini, all formerly in Helconinae. © 2011 The Authors. Systematic Entomology © 2011 The Royal Entomological Society.

Ilnyckyj A.,University of Manitoba
Canadian Journal of Gastroenterology | Year: 2010

BACKGROUND: The epidemiology of fecal incontinence (FI) remains incompletely understood. The use of different interview questions in highly selected populations has resulted in widely varying reported rates. AIM: To define the prevalence of idiopathic FI in a Canadian urban community sample using a validated interview questionnaire. METHODS: Respondents completed a telephone interview regarding bowel health as part of the 2006 Winnipeg Area Study (WAS). The WAS has been conducted annually by the Department of Sociology at the University of Manitoba (Winnipeg, Manitoba) since 1981. The household was the primary sampling unit. An eligible respondent was an individual 18 years of age or older who lived at that address, matched a randomly preassigned sex and provided consent. Respondents were asked whether they had ever been diagnosed by a physician with colon cancer, ulcerative colitis, Crohn's disease or irritable bowel syndrome. They were also asked, 'In the past 12 months have you experienced accidental leakage of liquid or solid stool?' Respondents were asked not to consider short-term diarrheal illness. Finally, respondents were asked to rank eight attributes of bowel habit on a 10-point scale. Answers ranking 5 points or greater were defined as having the attribute. RESULTS: In the city of Winnipeg, population 650,000, 1153 households were contacted. Of these, 727 (63%) agreed to participate and formed the study sample. Of the respondents, 361 were men and 366 were women (mean age 47 years). The sociodemographics of these respondents were comparable with those reported in previous WAS samples and the 2001 Canadian census data. Respondent cooperation, high interview quality and willingness for repeat contact were rated by the interviewers at 93%, 89% and 90%, respectively. FI was reported by 3.7% of the sample. There was no difference in sex or age of those reporting FI when compared with the rest of the sample. With physician-diagnosed gastrointestinal conditions removed from the analysis, 2.0% of the sample reported FI. Of the gastrointestinal conditions, only irritable bowel syndrome demonstrated a significant correlation with FI (one-sided χ2 test 11.567, degrees of freedom = 1; P=0.001). Four bowel habit attributes demonstrated strong correlation with FI (P=0.0001 for each t test): admission to any type of bowel accident, inability to delay toileting, inability to control passage of stool and need to wear a pad due to soiling. These four bowel habit attributes were reported (ranked 5 points or greater) by 1.5%, 22%, 2.4% and 1.5% of the sample, respectively. CONCLUSION: The prevalence of idiopathic FI in a well-defined community sample was 2.0%. There was no sex preference and the mean age of affected individuals was 47 years - demographic variables that did not vary among the sample. These findings suggest the need to develop a new paradigm beyond aging and childbirth injury to study the pathophysiology of FI. It is imperative to control for subjects with known irritable bowel syndrome in epidemiological studies because their inclusion in the present analysis doubled the calculated prevalence of FI. ©2010 Pulsus Group Inc. All rights reserved.

Arora R.C.,University of Manitoba
Acta neuropathologica communications | Year: 2014

INTRODUCTION: The pathogenesis of heart failure (HF) in diabetic individuals, called "diabetic cardiomyopathy", is only partially understood. Alterations in the cardiac autonomic nervous system due to oxidative stress have been implicated. The intrinsic cardiac nervous system (ICNS) is an important regulatory pathway of cardiac autonomic function, however, little is known about the alterations that occur in the ICNS in diabetes. We sought to characterize morphologic changes and the role of oxidative stress within the ICNS of diabetic hearts. Cultured ICNS neuronal cells from the hearts of 3- and 6-month old type 1 diabetic streptozotocin (STZ)-induced diabetic Sprague-Dawley rats and age-matched controls were examined. Confocal microscopy analysis for protein gene product 9.5 (PGP 9.5) and amino acid adducts of (E)-4-hydroxy-2-nonenal (4-HNE) using immunofluorescence was undertaken. Cell morphology was then analyzed in a blinded fashion for features of neuronal dystrophy and the presence of 4-HNE adducts.RESULTS: At 3-months, diabetic ICNS neuronal cells exhibited 30% more neurite swellings per area (p = 0.01), and had a higher proportion with dystrophic appearance (88.1% vs. 50.5%; p = <0.0001), as compared to control neurons. At 6-months, diabetic ICNS neurons exhibited more features of dystrophy as compared to controls (74.3% vs. 62.2%; p = 0.0448), with 50% more neurite branching (p = 0.0015) and 50% less neurite outgrowth (p = <0.001). Analysis of 4-HNE adducts in ICNS neurons of 6-month diabetic rats demonstrated twice the amount of reactive oxygen species (ROS) as compared to controls (p = <0.001).CONCLUSION: Neuronal dystrophy occurs in the ICNS neurons of STZ-induced diabetic rats, and accumulates temporally within the disease process. In addition, findings implicate an increase in ROS within the neuronal processes of ICNS neurons of diabetic rats suggesting an association between oxidative stress and the development of dystrophy in cardiac autonomic neurons.

Shan S.,University of Manitoba | Wang G.G.,Simon Fraser University
Journal of Mechanical Design, Transactions of the ASME | Year: 2010

Computational tools such as finite element analysis and simulation are widely used in engineering, but they are mostly used for design analysis and validation. If these tools can be integrated for design optimization, it will undoubtedly enhance a manufacturer's competitiveness. Such integration, however, faces three main challenges: (1) high computational expense of simulation, (2) the simulation process being a black-box function, and (3) design problems being high dimensional. In the past two decades, metamodeling has been intensively developed to deal with expensive black-box functions, and has achieved success for low dimensional design problems. But when high dimensionality is also present in design, which is often found in practice, there lacks of a practical method to deal with the so-called high dimensional, expensive, and black-box (HEB) problems. This paper proposes the first metamodel of its kind to tackle the HEB problem. This paper integrates the radial basis function with high dimensional model representation into a new model, RBF-HDMR. The developed RBF-HDMR model offers an explicit function expression, and can reveal (1) the contribution of each design variable, (2) inherent linearity/nonlinearity with respect to input variables, and (3) correlation relationships among input variables. An accompanying algorithm to construct the RBF-HDMR has also been developed. The model and the algorithm fundamentally change the exponentially growing computation cost to be polynomial. Testing and comparison confirm the efficiency and capability of RBF-HDMR for HEB problems. Copyright © 2010 by ASME.

Gietz R.D.,University of Manitoba
Methods in molecular biology (Clifton, N.J.) | Year: 2014

Efficient transformation of yeast has been the corner stone of molecular studies in yeast for numerous years. It is essential for techniques such as the yeast two-hybrid system as well as genome modification. Here I present protocols for a number of different transformation applications. A quick and easy protocol is for situations in which large numbers of transformants are not required. The high-efficiency protocol generates large numbers of transformants from small amounts of DNA that can be scaled up for the library transformation protocol. A transformation protocol for a microtiter plate format is also included. Finally, a protocol for the production of frozen competent yeast cells is included, which allows cells to be taken from the freezer at a moment's notice and transformed with high efficiency.

Slater J.,University of Manitoba
International Journal of Consumer Studies | Year: 2013

High population rates of obesity and nutrition-related chronic diseases warrant an examination of the role of food and nutrition education in health promotion. Using a mixed-methods approach, this study explored student enrolment trends in, and perceptions of, Home Economics Food and Nutrition education in a Canadian province. Enrolment in Home Economics Food and Nutrition courses for grades 7-12 was examined from 2000 to 2010 using administrative data. Perceptions of Home Economics Food and Nutrition education by home economics teachers and superintendents were investigated through in-depth interviews using a grounded theory approach. Results revealed that, although enrolment, including boys, increased slightly over the study period, the majority of children do not take Home Economics Food and Nutrition classes. Further, enrolment decreased significantly from grades 7 (45.77%) to 12 (7.61%). Home Economics Food and Nutrition education faces significant challenges to its future viability. These include: many school administrators, non-home economics teachers and some parents do not value Home Economics Food and Nutrition education; Home Economics Food and Nutrition education is seen as less valuable than math and science for future career planning; outdated curriculum and teaching infrastructure; reduced numbers of new home economics teachers; decreasing student food knowledge and skills; and changing social norms regarding food and eating (increased use of convenience foods across population groups, a youth 'fast food culture' and fewer family meals). Results also indicated that Home Economics Food and Nutrition education is seen as critically important for youth, given that one third of Canadian children are now overweight or obese, fast and highly processed foods make up an increasing proportion of Canadians' diets, and there are increasing dilemmas being faced with food production and food safety. These results signal a growing tension between societal trends towards technological solutions in education and everyday living, and the growing acknowledgement of the externalities associated with these trends including poor health and environmental impacts. Consequently, evidence-based food and nutrition education that is relevant for today's food environment and busy lifestyles is warranted to improve the health of current and future generations. This should be based on a comprehensive food and nutrition framework including functional, interactive and critical 'food literacy'. Policy measures are urgently required to ensure all youth have access to food literacy education. © 2013 John Wiley & Sons Ltd.

We discuss the random walk of magnetic field lines in astrophysical plasmas. Based on the standard theory of field line diffusion we show that there are two asymptotic limits. In these limits field line wandering is universal because in both regimes the field line diffusion coefficient depends only on fundamental length scales and absolute magnetic field strengths. As examples we discuss the field line diffusion coefficient for different prominent turbulence models namely the slab model, the two-dimensional model, and the Goldreich-Sridhar model. We show that the field line diffusion coefficient for the latter model agrees with the results obtained for slab and two-dimensional turbulence in limiting cases. We also discuss the transport of energetic particles perpendicular with respect to the mean magnetic field. Based on the unified nonlinear transport theory we consider again asymptotic limits. It is shown that one can identify four different regimes in which the transport is again universal. In all four cases perpendicular transport only depends on fundamental length scales of turbulence, magnetic field values, and the parallel diffusion coefficient. © 2013 Published by Elsevier Ltd. on behalf of COSPAR. All rights reserved.

Salman M.S.,University of Manitoba
Current Neurology and Neuroscience Reports | Year: 2015

Infantile-onset saccade initiation delay, also known as congenital ocular motor apraxia, typically presents in early infancy with horizontal head thrusts once head control is achieved. Defective initiation of horizontal saccades and saccade hypometria with normal saccadic velocity are characteristic findings. Isolated impairment of vertical saccades is rare. Impaired smooth ocular pursuit may be seen. Other relatively common features include developmental delay, hypotonia, ataxia, or clumsiness. Brain MRI may be normal or show a diverse range of abnormalities, most commonly involving the cerebellum. Defective slow phases of the optokinetic response are commonly associated with brain MRI abnormalities. Isolated defect of vertical saccade initiation may indicate supratentorial brain abnormalities on MRI. Joubert syndrome, a developmental midbrain-hindbrain malformation, and ataxia telangiectasia are both commonly associated with defective volitional and reflexive saccade initiation, saccade hypometria, and head thrusts. Both horizontal and vertical saccades are impaired in these two disorders. © 2015, Springer Science+Business Media New York.

Leslie W.D.,University of Manitoba | Lix L.M.,University of Saskatchewan | Wu X.,University of Saskatchewan
Osteoporosis International | Year: 2013

Failure to account for competing mortality gave higher estimates of 10-year fracture probability than if appropriate adjustment is made for competing mortality, particularly among subgroups with higher mortality. A modified Kaplan-Meier method is easy to implement and provides an alternative approach to existing methods for competing mortality risk adjustment. Introduction: A unique feature of FRAX® is that 10-year fracture probability accounts for mortality as a competing risk. We compared the effect of competing mortality adjustment on nonparametric and parametric methods of fracture probability estimation. Methods: The Manitoba Bone Mineral Density (BMD) database was used to identify men and women age ≥50 years with FRAX probabilities calculated using femoral neck BMD (N = 39,063). Fractures were assessed from administrative data (N = 2,543 with a major osteoporotic fracture, N = 549 with a hip fracture during mean 5.3 years follow-up). Results: The following subgroups with higher mortality were identified: men, age >80 years, high fracture probability, and presence of diabetes. Failure to account for competing mortality in these subgroups overestimated fracture probability by 16-56 % with the standard nonparametric (Kaplan-Meier) method and 15-29 % with the standard parametric (Cox) model. When the outcome was hip fractures, failure to account for competing mortality overestimated hip fracture probability by 18-36 % and 17-35 %, respectively. A simple modified Kaplan-Meier method showed very close agreement with methods that adjusted for competing mortality (within 2 %). Conclusions: Failure to account for competing mortality risk gives considerably higher estimates of 10-year fracture probability than if adjustment is made for this competing risk. © 2012 International Osteoporosis Foundation and National Osteoporosis Foundation.

Oguzoglu U.,University of Manitoba
Health Economics | Year: 2010

This paper examines the impact of self-reported work limitations on the labour force participation of the Australian working age population. Five consecutive waves of the Household, Income and Labour Dynamics in Australia (HILDA) Survey are used to investigate this relationship. A two-equation dynamic panel data model demonstrates that persistence and unobserved heterogeneity play an important role in work limitation reporting and its effect on labour force participation. Unobserved factors that jointly drive work limitation and participation are also shown to be crucial, especially for women. Copyright © 2009 John Wiley & Sons, Ltd.

Shrestha B.,Intel Corporation | Hossain E.,University of Manitoba | Choi K.W.,Seoul National University of Science and Technology
IEEE Transactions on Wireless Communications | Year: 2014

The strength of carrier-sense multiple access with collision avoidance (CSMA/CA) can be combined with that of time-division multiple access (TDMA) to enhance the channel access performance in wireless networks such as the IEEE 802.15.4-based wireless personal area networks. In particular, the performance of legacy CSMA/CA-based medium access control scheme in congested networks can be enhanced through a hybrid CSMA/CA-TDMA scheme while preserving the scalability property. In this paper, we present distributed and centralized channel access models that follow the transmission strategies based on Markov decision process (MDP) to access both contention period and contention-free period in an intelligent way. The models consider the buffer status as an indication of congestion provided that the offered traffic does not exceed the channel capacity. We extend the models to consider the hidden node collision problem encountered due to the signal attenuation caused by channel fading. The simulation results show that the MDP-based distributed channel access scheme outperforms the legacy slotted CSMA/CA scheme. The centralized model outperforms the distributed model but requires the global information of the network. © 2014 IEEE.

Camargo C.A.,Harvard University | Guana A.,Sanofi S.A. | Wang S.,Sanofi S.A. | Simons F.E.R.,University of Manitoba
Journal of Allergy and Clinical Immunology: In Practice | Year: 2013

Background: Auvi-Q is a novel epinephrine autoinjector (EAI) that provides audio and visual cues for patients at risk for life-threatening allergic reactions. Objective: We tested the preference for Auvi-Q or EpiPen with regard to method of instruction, preference to carry, device size, and device shape. Methods: This large, multicenter, simulated-use study evaluated whether adults (aged 18-65 years), caregivers (parents/guardians aged 18-65 years of children aged 5-17 years), and children (aged 11-17 years), with and without experience in using an EAI, had a preference for the current design of Auvi-Q or the current design of EpiPen. Participants were given a scenario that involved anaphylaxis and were instructed to simulate use of an EAI. They received and tested each device individually according to the randomization assignment. After testing both devices, they completed a survey to indicate their preference for Auvi-Q versus EpiPen. Results: Among all 693 participants combined, Auvi-Q was preferred over EpiPen on all study end points (P < .001). For experienced and inexperienced participants in all 3 groups (adults, caregivers, and children), Auvi-Q was preferred over EpiPen for method of instruction, preference to carry, and device size (all P < .001). The preference for Auvi-Q device shape was not significant among experienced children (P = .10); however, it was significant for inexperienced children (P = .04) and highly significant for experienced and inexperienced adults and caregivers (P < .001). Conclusion: In this large multicenter, simulated-use study, Auvi-Q was preferred over EpiPen by experienced and inexperienced adults, caregivers, and children. © 2013 American Academy of Allergy, Asthma & Immunology.

Bernstein C.N.,University of Manitoba | Ng S.C.,Chinese University of Hong Kong | Lakatos P.L.,Semmelweis University | Moum B.,University of Oslo | Loftus Jr. E.V.,Mayo Medical School
Inflammatory Bowel Diseases | Year: 2013

Standardized mortality rates in ulcerative colitis (UC) are no different than that in the general population. Patients who are older and have more comorbidities have increased mortality. Emergent colectomy still carries 30-day mortality rates of approximately 5%. In more recent studies, UC surgery rates at 10 years from diagnosis are nearly 3% in Hungary, <10% in referral center studies from Asia, approximately 10% in Norway, the European Cohort Study of Inflammatory Bowel Diseases and Manitoba, Canada, and nearly 17% in Olmsted County, Minnesota. These rates are for the most part lower than reported colectomy rates from studies completed before 1990. Short-term colectomy rates in severe hospitalized UC have remained stable at 27% for several years. Generally, children seem to have higher rates of extensive colitis at diagnosis than adults. There also seems to be higher rates of colectomy in children than in adults (i.e., at least 20% at 10 years), and perhaps, this reflects a higher rate of extensive disease. Acute severe colitis in patients with UC still represents a condition with a high early colectomy rate and a measurable mortality rate. Copyright © 2013 Crohn's & Colitis Foundation of America, Inc.

Dufault B.,University of Manitoba | Klar N.,University of Western Ontario
American Journal of Epidemiology | Year: 2011

The ecologic study design is routinely used by epidemiologists in spite of its limitations. It is presently unknown how well the challenges of the design are dealt with in epidemiologic research. The purpose of this bibliometric review was to critically evaluate the characteristics, statistical methods, and reporting of results of modern cross-sectional ecologic papers. A search through 6 major epidemiology journals identified all cross-sectional ecologic studies published since January 1, 2000. A total of 125 articles met the inclusion requirements and were assessed via common evaluative criteria. It was found that a considerable number of cross-sectional ecologic studies use unreliable methods or contain statistical oversights; most investigators who adjusted their outcomes for age or sex did so improperly (64%), statistical validity was a potential issue for 20% of regression models, and simple linear regression was the most common analytic approach (31%). Many authors omitted important information when discussing the ecologic nature of their study (31%), the choice of study design (58%), and the susceptibility of their research to the ecological fallacy (49%). These results suggest that there is a need for an international set of guidelines that standardizes reporting on ecologic studies. Additionally, greater attention should be given to the relevant biostatistical literature. © 2011 The Author.

Fenyo D.,New York University | Beavis R.C.,University of Manitoba
Bioinformatics | Year: 2015

Summary: The Global Proteome Machine and Database (GPMDB) representational state transfer (REST) service was designed to provide simplified access to the proteomics information in GPMDB using a stable set of methods and parameters. Version 1 of this interface gives access to 25 methods for retrieving experimental information about protein post-translational modifications, amino acid variants, alternate splicing variants and protein cleavage patterns. © The Author 2015. Published by Oxford University Press.

Shalchi A.,University of Manitoba
Astrophysical Journal | Year: 2011

New analytic forms for the parallel diffusion coefficient with adiabatic focusing are presented. For isotropic pitchangle diffusion, we derive an exact formula for the parallel diffusion coefficient. Those results are correct for weak and strong focusing. For arbitrary pitch-angle scattering, we derive an approximation which is exact up to second order in the focusing strength. Examples and a comparison with previous results are presented too. © 2011. The American Astronomical Society.

Orr P.,University of Manitoba
International Journal of Circumpolar Health | Year: 2011

Objectives. In a 2-part series, the current literature with respect to adherence to tuberculosis care among Canadian Aboriginal populations is reviewed. In the current paper, which comprises part 2 of this review, strategies to remove barriers to TB adherence and to sustain and improve adherence are explored. Study design. Literature review. Methods. The biomedical and social science literature, including electronic databases (PubMed, PsychINFO, MEDLINE, Native Health Database. Scopus, Social Science Citation Index) were searched and reviewed with regard to relevant studies on adherence to health care, and to tuberculosis care specifically. Results. The majority of published studies of interventions to remove barriers to TB adherence are focused on the health service system and on the individual. The former include enhanced programs of directly observed therapy and directly observed preventive therapy, as well as "permeable" health services that require minimal negotiation. At the personal level, effort must be made to develop a shared knowledge of and care plan for TB, which includes Indigenous and Western scientific health beliefs and practice. The quality of the relationship between health care provider and patient is critical to the outcome of educational efforts that support adherence. Few studies address interventions within the social context, and few have used participatory methodologies in partnership with families and communities. Social supports such as assistance with childcare, transportation and shelter have been shown to be associated with improved adherence to care for other conditions. TB programs may wish to use techniques used in other health programs, such as the identification of patient "sponsors" or mentors, or the use of verbal and/or written "contracts." Conclusions. Many of the interventional studies addressing health system barriers to TB adherence are grounded in the view that the problem rests with the patient. What is required is an approach that is responsive to the patient's needs while holding the patient to his or her personal and societal responsibilities. Adherence to therapy is unlikely to improve in a substantial way unless Indigenous beliefs about causation and care are incorporated into a program which has meaning for the patient.

Orr P.,University of Manitoba
International Journal of Circumpolar Health | Year: 2011

Objectives. In a 2-part series, the current literature with respect to adherence to tuberculosis care among Canadian Aboriginal populations is reviewed. In the current paper, which comprises part 1 of this review, adherence is defined, and methods of measurement, issues of responsibility and potential barriers to adherence are explored. Study design. Literature review. Methods. A systematic search and analytic review of relevant studies was undertaken, including an online search of electronic databases (PubMed, PsychINFO, MEDLINE, Native Health Database, Scopus, Social Science Citation Index) and publications by governmental and non-governmental agencies. Results. Poor adherence to therapy for TB disease is the most common cause of initial treatment failure and of disease relapse worldwide. Adherence to care for TB disease is necessary for the health of both the affected individual and society as a whole. Adherence is a task-specific behaviour that is not inherent to ethnic identity. The term applies only when common agreement over a care plan has been reached between patient and provider. The International Standards for Tuberculosis Care and the Patients Charter outline the responsibilities for adherence on the part of both patients and providers. For Canadian Aboriginals, barriers to adherence may derive from a complex interaction between the health system, personal factors and social factors, which may include dysfunctional acute and public health systems, dissonant (between health care provider and patient) belief systems, concurrent co-morbidities and life stressors, poverty and social stigma. Conclusions. Adherence is a task-specific behaviour, not a personality trait. It is influenced by the interaction of systemic, personal and societal factors. These factors must be understood within the historical experience of TB and the cultural meaning of health and illness among Indigenous Canadians.

Elias B.,University of Manitoba
Social Science and Medicine | Year: 2014

Infant mortality is a metric influenced by societal, political and medical advances. The way vital events are collected and reported are not always uniform. A lack of uniformity has disadvantaged some groups in society. In Canada, a multi-jurisdictional vital statistics system has truncated our ability to produce infant mortality rates for the Indigenous population. To understand how this evolved, this paper outlines the history of infant mortality, generally and internationally, and then documents the efforts to harmonize the collection and reporting of vital statistics (births and deaths) in Canada. Following this analysis is a historical review of vital event reporting for Canada's Indigenous population. A major finding of this paper is that racism, reframing, and jurisdictional posturing has limited our ability to accurately estimate live births and infant deaths for the Indigenous population. To improve Indigenous infant mortality estimation, Canada's governments need to transcend multijurisdictional challenges and fulfill international reporting obligations to Indigenous communities. © 2014.

Hajmohammad S.,University of Manitoba | Vachon S.,University of Western Ontario
Journal of Supply Chain Management | Year: 2016

This study takes a conceptual theory building approach to develop a framework for managing supplier sustainability risk-the adverse impact on a buying organization from a supplier's social or environmental misconduct. Using anecdotal evidence and the literature, we present four distinct risk management strategies that supply managers adopt: risk avoidance, monitoring-based risk mitigation, collaboration-based risk mitigation, and risk acceptance. Drawing on agency and resource dependence theories, we study how the interactions of two key risk management predictors-that is, the supply managers' perceived risk and the buyer-supplier dependence structure-affect supply managers' strategy choice. Specifically, we propose that a collaborative-based mitigation strategy, involving direct interaction and solution development with the suppliers, is selected by supply managers in a high perceived risk-buyer dominant context. In a low perceived risk-buyer dominant context, however, a monitoring-based mitigation strategy is preferred. When the buyer and the supplier are not dependent on each other and there is a low perceived risk, the supply managers accept the risk by taking no actions, whereas in a high perceived risk-independent context the supply managers would avoid the risk by terminating the relationship with the supplier. We conclude the study by describing the theoretical contributions and managerial implications of the study as well as the avenues for future research. © 2016 Institute for Supply Management, Inc.

Electrical synaptic transmission via gap junctions has become an accepted feature of neuronal communication in the mammalian brain, and occurs often between dendrites of interneurons in major brain structures, including the hippocampus. Electrical and dye-coupling has also been reported to occur between pyramidal cells in the hippocampus, but ultrastructurally-identified gap junctions between these cells have so far eluded detection. Gap junctions can be formed by nerve terminals, where they contribute the electrical component of mixed chemical/electrical synaptic transmission, but mixed synapses have only rarely been described in mammalian CNS. Here, we used immunofluorescence localization of the major gap junction forming protein connexin36 to examine its possible association with hippocampal pyramidal cells. In addition to labeling associated with gap junctions between dendrites of parvalbumin-positive interneurons, a high density of fine, punctate immunolabeling for Cx36, non-overlapping with parvalbumin, was found in subregions of the stratum lucidum in the ventral hippocampus of rat brain. A high percentage of Cx36-positive puncta in the stratum lucidum was localized to mossy fiber terminals, as indicated by co-localization of Cx36-puncta with the mossy terminal marker vesicular glutamate transporter-1, as well as with other proteins that are highly concentrated in, and diagnostic markers of, these terminals. These results suggest that mossy fiber terminals abundantly form mixed chemical/electrical synapses with pyramidal cells, where they may serve as intermediaries for the reported electrical and dye-coupling between ensembles of these principal cells. This article is part of a Special Issue entitled Electrical Synapses. © 2012 Elsevier B.V.

Craig D.B.,University of Winnipeg | Morris T.T.,University of Winnipeg | Ong-Justiniano C.M.Q.,University of Manitoba
Analytical Chemistry | Year: 2012

Escherichia coli β-galactosidase was incubated in the presence of the slow-release inhibitor d-galactal for 30 min at a concentration of 70 times its K i. The sample was then diluted 20000-fold into buffer containing the fluorogenic substrate 9H-(1,3-dichloro-9,9-dimethylacridin-2-on-7-yl) β-d-galactoside, reducing the inhibitor concentration to K i/280. The sample was subjected to a capillary electrophoresis continuous flow single enzyme molecule assay. As the inhibitor dissociated while the enzyme traveled the length of the capillary, a fraction of molecules showed stepwise increases in activity. This was due to the activation of individual subunits within single molecules. The changes in activity can be largely explained in terms of each molecule containing subunits of indistinguishable activity. © 2012 American Chemical Society.

Chernick V.,University of Manitoba
Paediatric Respiratory Reviews | Year: 2012

This paper is an attempt to convey in a lucid way how to go about writing a scientific article for publication in an appropriate journal. Topics covered . are: a) reasons to write a paper b) types of papers c) asking a question and formulating an hypothesis d) the complex series of steps necessary before you begin your study e) additional considerations once your study is complete f) the process of writing the paper and g) writing skills. In the concluding remarks I comment on the possibility of rejection of your submission which should not be taken personally. If this does occur it should not deter you from contributing to medical science. © 2011 .

Gough S.C.L.,Oxford Center for Diabetes | Harris S.,University of Western Ontario | Woo V.,University of Manitoba | Davies M.,University of Leicester
Diabetes, Obesity and Metabolism | Year: 2013

All the basal insulin products currently available have suboptimal pharmacokinetic (PK) properties, with none reliably providing a reproducible and peakless pharmacodynamic (PD) effect that endures over 24 h from once-daily dosing. Insulin degludec is a novel acylated basal insulin with a unique mechanism of protracted absorption involving the formation of a depot of soluble multihexamer chains after subcutaneous injection. PK/PD studies show that insulin degludec has a very long duration of action, with a half-life exceeding 25 h. Once-daily dosing produces a steady-state profile characterized by a near-constant effect, which varies little from injection to injection in a given patient. Clinically, insulin degludec has been shown consistently to carry a lower risk of nocturnal hypoglycaemia than once-daily insulin glargine, in both basal+bolus and basal-only insulin regimens. The constancy of the steady-state profile of insulin degludec also means that day-to-day irregularities at the time of injection have relatively little PD influence, thereby offering the possibility of greater treatment flexibility for patients. © 2012 Blackwell Publishing Ltd.

Weber R.E.,University of Aarhus | Campbell K.L.,University of Manitoba
Acta Physiologica | Year: 2011

As demonstrated by August Krogh et al. a century ago, the oxygen-binding reaction of vertebrate haemoglobin is cooperative (described by sigmoid O2 equilibrium curves) and modulated by CO2 and protons (lowered pH) that - in conjunction with later discovered allosteric effectors (chloride, lactate and organic phosphate anions) - enhance O2 unloading from blood in relatively acidic and oxygen-poor tissues. Based on the exothermic nature of the oxygenation of the haem groups, haemoglobin-O2 affinity also decreases with rising temperature. This thermal sensitivity favours oxygen unloading in warm working muscles, but may become detrimental in regionally heterothermic animals, for example in cold-tolerant birds and mammals and warmbodied fish, where it may perturb the balance between O2 unloading and O2 requirement in organs with substantially different temperatures than at the respiratory organs and thus commonly is reduced or obliterated. Given that the oxygenation of haemoglobin is linked with the endothermic release of allosteric effectors, increased effector interaction is an effective strategy that is widely exploited to achieve adaptive reductions in the temperature dependence of blood-O2 affinity. The molecular mechanisms implicated in heterothermic vertebrates from different taxonomic groups reveal remarkable variability, both as regards the effectors implicated (protons in tunas, organic phosphates in sharks and billfish, chloride ions in ruminants and chloride and phosphate anions in the extinct woolly mammoth, etc.) and binding sites for the same effectors, indicating multiple evolutionary origins, but convergent physiological functionality (reductions in temperature dependence of O2-binding affinity that safeguard tissue O2 supply). © 2010 The Authors.

Shalchi A.,University of Manitoba
Astrophysical Journal | Year: 2015

In the past different analytic limits for the perpendicular diffusion coefficient of energetic particles interacting with magnetic turbulence were discussed. These different limits or cases correspond to different transport modes describing how the particles are diffusing across the large-scale magnetic field. In the current paper we describe a new transport regime by considering the model of noisy reduced magnetohydrodynamic turbulence. We derive different analytic forms of the perpendicular diffusion coefficient, and while we do this, we focus on the aforementioned new transport mode. We show that for this turbulence model a small perpendicular diffusion coefficient can be obtained so that the latter diffusion coefficient is more than hundred times smaller than the parallel diffusion coefficient. This result is relevant to explain observations in the solar system where such small perpendicular diffusion coefficients have been reported. © 2015. The American Astronomical Society. All rights reserved.

Liu D.,University of Manitoba
Frontiers in cellular and infection microbiology | Year: 2012

The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility.

Feldmann H.,National Institute of Allergy and Infectious Diseases | Feldmann H.,University of Manitoba | Geisbert T.W.,University of Texas Medical Branch
The Lancet | Year: 2011

Ebola viruses are the causative agents of a severe form of viral haemorrhagic fever in man, designated Ebola haemorrhagic fever, and are endemic in regions of central Africa. The exception is the species Reston Ebola virus, which has not been associated with human disease and is found in the Philippines. Ebola virus constitutes an important local public health threat in Africa, with a worldwide effect through imported infections and through the fear of misuse for biological terrorism. Ebola virus is thought to also have a detrimental effect on the great ape population in Africa. Case-fatality rates of the African species in man are as high as 90, with no prophylaxis or treatment available. Ebola virus infections are characterised by immune suppression and a systemic inflammatory response that causes impairment of the vascular, coagulation, and immune systems, leading to multiorgan failure and shock, and thus, in some ways, resembling septic shock. © 2011 Elsevier Ltd.

Nicolle L.E.,University of Manitoba
Antimicrobial Resistance and Infection Control | Year: 2014

Urinary tract infection attributed to the use of an indwelling urinary catheter is one of the most common infections acquired by patients in health care facilities. As biofilm ultimately develops on all of these devices, the major determinant for development of bacteriuria is duration of catheterization. While the proportion of bacteriuric subjects who develop symptomatic infection is low, the high frequency of use of indwelling urinary catheters means there is a substantial burden attributable to these infections. Catheter-acquired urinary infection is the source for about 20% of episodes of health-care acquired bacteremia in acute care facilities, and over 50% in long term care facilities. The most important interventions to prevent bacteriuria and infection are to limit indwelling catheter use and, when catheter use is necessary, to discontinue the catheter as soon as clinically feasible. Infection control programs in health care facilities must implement and monitor strategies to limit catheter-acquired urinary infection, including surveillance of catheter use, appropriateness of catheter indications, and complications. Ultimately, prevention of these infections will require technical advances in catheter materials which prevent biofilm formation. © 2014 Nicolle; licensee BioMed Central Ltd.

Zurba M.,University of Manitoba
Environmental Policy and Governance | Year: 2014

This paper looks at the potential for collaborative governance for land and resources to become a form of on-going reconciliation in societies transitioning from past oppression and on-going social injustice. Structural violence in the form of capacity disparities and policy configuration are explored in order to frame the discussion. Canada and South Africa are presented as two countries that have been going through different experiences in terms of transition, but have had similar experiences in regards to a need to foster new ways of working towards more equitable forms of governance. Here, much like reconciliation, governance is presented as a process, which under the right conditions can lead to relationship building and mutually desirable outcomes. This process creates a platform for establishing common ground, as well as the potential to negotiate solutions to structural violence. © 2013 John Wiley & Sons, Ltd and ERP Environment.

Araji M.T.,University of Manitoba | Shakour S.A.,Abu Dhabi University
Materials and Design | Year: 2013

Sustainable soft materials in design applications should aim to have less resources depletion and pollution, plus inevitably less toxicity for the entire ecosystem. The outcome would result in environmental benefits, particularly with the production, specification and usage of proper materials. For this purpose, the paper conducted a survey among manufactures, designers and end-users to explore the concerns related to the inconsequential consideration of environmental factors associated with the extraction, processing, fabrication, and selection process of soft materials. Four criteria, including aesthetical, functional, economical, and environmental, were examined based on a comprehensive set of 33 governing factors. The analysis concludes criteria response rates that capture the intensity of the respondents experience using a three-point Likert scale. Analysis of Variance (ANOVA) was further considered to determine differences and interaction between independent and dependent variables. Results show that the main effect for criteria is not significant, but there are mean differences in consideration of criteria when respondents are evaluating factors based on the rating scale. Overall, the interaction variation and plots highlight the statistically significant differences between criteria. The environmental criterion is of marginal importance to all populations. © 2012 Elsevier Ltd.

Zeiler F.A.,University of Manitoba
Critical Care Research and Practice | Year: 2015

Refractory status epilepticus (RSE) and superrefractory status epilepticus (SRSE) pose a difficult clinical challenge. Multiple cerebral receptor and transporter changes occur with prolonged status epilepticus leading to pharmacoresistance patterns unfavorable for conventional antiepileptics. In particular, n-methyl-d-aspartate (NMDA) receptor upregulation leads to glutamate mediated excitotoxicity. Targeting these NMDA receptors may provide a novel approach to otherwise refractory seizures. Ketamine has been utilized in RSE. Recent systematic review indicates 56.5% and 63.5% cessation in seizures in adults and pediatrics, respectively. No complications were described. We should consider earlier implementation of ketamine or other NMDA receptor antagonists, for RSE. Prospective study of early implementation of ketamine should shed light on the role of such medications in RSE. © 2015 F. A. Zeiler.

Knecht H.,Universite de Sherbrooke | Mai S.,University of Manitoba
Journal of Cellular Physiology | Year: 2011

Patient samples are evaluated by experienced pathologists whose diagnosis guides treating physicians. Pathological diagnoses are complex and often assisted by the application of specific tissue markers. However, cases still exist where pathologists cannot distinguish between closely related entities or determine the aggressiveness of the disease they identify under the microscope. This is due to the absence of reliable markers that define diagnostic subgroups in several cancers. Three-dimensional (3D) imaging of nuclear telomere signatures is emerging as a new tool that may change this situation offering new opportunities to the patients. This article will review current and future avenues in the assessment of diagnostic patient samples. © 2010 Wiley-Liss, Inc.

Zhang Y.,University of Manitoba | Rempel C.,Canola Council of Canada | Liu Q.,Agriculture and Agri Food Canada
Critical Reviews in Food Science and Nutrition | Year: 2014

Canola Council of Canada, Winnipeg, Manitoba, Canada The rising costs of nonrenewable feedstocks and environmental concerns with their industrial usage have encouraged the study and development of renewable products, including thermoplastic starch (TPS). Starch is an abundant, plant-based biodegradable material with interesting physicochemical characteristics that can be exploited, and this has received attention for development of TPS products. Starch exhibits usable thermoplastic properties when plasticizers, elevated temperatures, and shear are present. The choice of plasticizer has an effect on TPS, even when these have similar plasticization principles. Most TPS have glass transition temperature, Tg, in the range of approximately -75 to 10°C. Glassy transition of TPS is detected by differential scanning calorimeter (DSC) and thermodynamic analyzer (DMA), although DMA has been found to be more sensitive and effective. TPS has low tensile properties, typically below 6 MPa in tensile strength (TS). The addition of synthetic polymers, nanoclay, and fiber can improve TS and water-resistance ability. The moisture sorption behavior of TPS is described in GAB and BET models, from which monolayer moisture content and specific area are derived. Current studies on surface tension, gas permeability, crystallinity, and so on of the TPS are also reviewed. © 2014 Copyright Taylor and Francis Group, LLC.

Burgener A.,Public Health Agency of Canada | Burgener A.,University of Manitoba | Burgener A.,Karolinska Institutet | McGowan I.,University of Pittsburgh | And 3 more authors.
Current Opinion in Immunology | Year: 2015

The mucosal barrier plays an integral function in human health as it is the primary defense against pathogens, and provides a critical transition between the external environment and the human internal body. In the context of HIV infection, the most relevant mucosal surfaces include those of the gastrointestinal (GI) and genital tract compartments. Several components help maintain the effectiveness of this mucosal surface, including the physical anatomy of the barrier, cellular immunity, soluble factors, and interactions between the epithelial barrier and the local microenvironment, including mucus and host microbiota. Any defects in barrier integrity or function can rapidly lead to an increase in acquisition risk, or with established infection may result in increased pathogenesis, morbidities, or mortality. Indeed, a key feature to all aspects of HIV infection from transmission to pathogenesis is disruption and/or dysfunction of mucosal barriers. Herein, we will detail the host-pathogen relationship of HIV and mucosal barriers in both of these scenarios. © 2015.

Targownik L.E.,University of Manitoba
American Journal of Gastroenterology | Year: 2014

OBJECTIVES:Opioids are commonly used in the treatment of pain and associated symptoms of inflammatory bowel disease (IBD). The continuous use of opioids has been associated with adverse outcomes, including death. The prevalence and the risk factors for opioid use in IBD are poorly characterized.METHODS:We used the population-based Manitoba IBD Epidemiology Database to identify all individuals in Manitoba with IBD who were prescribed opioids both before and following diagnosis. We determined the point prevalence of any opioid use, as well as the risk of becoming a heavy opioid user (defined as continuous use for 30 days at a dose exceeding 50 mg morphine/day or equivalent). Logistic regression and Cox proportional hazards models were generated to assess whether IBD was an independent risk factor for opioid use, the risk factors for opioid use in individuals with IBD, and to determine whether opioid use was associated with excess mortality in IBD.RESULTS:Within 10 years of diagnosis, 5% of individuals with IBD had become heavy opioid users. Moderate use of opioids before diagnosis was strongly predictive of future heavy use. Individuals with IBD were significantly more likely to become heavy opioid users than their matched controls (odds ratio (OR) 2.91, 95% confidence interval (CI) 2.19-3.85). Heavy opioid use was strongly associated with mortality (OR 2.82, 95% CI 1.58-5.02).CONCLUSIONS:IBD is an independent risk factor for becoming a heavy opioid user, and heavy opioid use is associated with excess mortality in IBD patients. Clinicians should recognize risk factors for future heavy opioid use among their patients with IBD.Am J Gastroenterol advance online publication, 2 September 2014; doi:10.1038/ajg.2014.230.

Kiarie E.,DuPont Company | Romero L.F.,DuPont Company | Nyachoti C.M.,University of Manitoba
Nutrition Research Reviews | Year: 2013

The value of added feed enzymes (FE) in promoting growth and efficiency of nutrient utilisation is well recognised in single-stomached animal production. However, the effects of FE on the microbiome of the gastrointestinal tract (GIT) are largely unrecognised. A critical role in host nutrition, health, performance and quality of the products produced is played by the intestinal microbiota. FE can make an impact on GIT microbial ecology by reducing undigested substrates and anti-nutritive factors and producing oligosaccharides in situ from dietary NSP with potential prebiotic effects. Investigations with molecular microbiology techniques have demonstrated FE-mediated responses on energy utilisation in broiler chickens that were associated with certain clusters of GIT bacteria. Furthermore, investigations using specific enteric pathogen challenge models have demonstrated the efficacy of FE in modulating gut health. Because FE probably change the substrate characteristics along the GIT, subsequent microbiota responses will vary according to the populations present at the time of administration and their reaction to such changes. Therefore, the microbiota responses to FE administration, rather than being absolute, are a continuum or a population of responses. However, recognition that FE can make an impact on the gut microbiota and thus gut health will probably stimulate development of FE capable of modulating gut microbiota to the benefit of host health under specific production conditions. The present review brings to light opportunities and challenges for the role of major FE (carbohydrases and phytase) on the gut health of poultry and swine species with a specific focus on the impact on GIT microbiota. © The Authors 2013.

Slominski B.A.,University of Manitoba
Poultry Science | Year: 2011

Exogenous enzymes have been used extensively in the diets of poultry to improve productive performance. Further research, however, is needed to evaluate the efficacy of enzyme use and for the expansion of the use of enzymes to accommodate the wide array of dietary constituents used in poultry feeding programs. The use of effective phytase preparations to improve bird performance and to reduce environmental P pollution has shown less than optimum results, partly due to the potential negative effects of nontargeted dietary fiber components and to confounding influence of inadequate knowledge of accurate P requirements and the tendency for the use of excessive safety margins in diet formulation. Targeting specific nonstarch polysaccharides (NSP) of wheat, barley, or rye with enzyme preparations has proven effective for diets based on these cereals but not for corn- and soybean meal-based diets, primarily due to the differences in constituent NSP. The increased use of whole flaxseed in poultry diets represents an additional research area for effective enzyme development to alleviate potential negative effects of constituent NSP components. Such challenges of the enzyme development process and their outcomes are presented in this publication. © 2011 Poultry Science Association Inc.

Choi K.W.,Seoul National University of Science and Technology | Hossain E.,University of Manitoba
IEEE Transactions on Signal Processing | Year: 2013

For a cognitive radio (CR) system, we investigate the estimation problem in which a secondary user (SU) estimates the channel parameters such as the sojourn times on the active and the inactive states of the primary user (PU) as well as the PU signal strength on the basis of the sequence of the sensing results. By modeling the CR system as a hidden Markov model (HMM), the channel parameters are estimated by the standard expectationmaximization (EM) algorithm. We focus on mathematically analyzing the condition under which the EM algorithm can find the true channel parameters. For this, we apply the theory of the equivalence and the identifiability to the proposedHMMmodel for a CR system. Based on the identifiability analysis, we propose a parameter estimation algorithm for our problemby extending the EMalgorithm. The numerical results show that the proposed algorithm successfully estimates the true channel parameters as long as the condition for finding the channel parameters is satisfied. © 2012 IEEE.

Sabourin J.N.,University of Alberta | Burnett M.,University of Manitoba
Journal of Obstetrics and Gynaecology Canada | Year: 2012

Objective: To review the legal status of abortion and its prevalence, safety, and accessibility in Canada and to highlight related areas of concern. Methods: We conducted a review of research literature, published reports, websites, and articles in order to describe abortion services and associated issues such as access, availability, and safety in Canada. Results: Therapeutic abortion is often the result of unintended pregnancy. Even so, emergency contraception may not be accessible for all Canadian women, and effective contraception is underutilized. In Canada, abortion has been decriminalized and is generally safe, but current reports of prevalence and complication rates are inconsistent. Abortion rates appear to be decreasing. Medical or surgical termination of pregnancy is available and often publicly funded. However, barriers related to time, cost, travel, and regional disparities hamper unrestricted access to therapeutic abortion in this country, and although the place of abortion in medical education remains controversial, current curriculum content appears to be inadequate. Conclusions: The Society of Obstetricians and Gynaecologists of Canada states that comprehensive family planning services, including therapeutic abortion, should be freely available to all. The Canadian Medical Association affirms that induced abortion should be uniformly available to all women. In Canada, the issues related to therapeutic abortion access, availability, and safety must be addressed. © 2012 Society of Obstetricians and Gynaecologists of Canada.

Hechter R.P.,University of Manitoba
Computers in the Schools | Year: 2012

Teacher education programs across North America are transforming. What were once piecemeal programs consisting of often unrelated courses are now becoming coherent and intertwined trajectories toward teacher certification. Part of this transformation can be attributed to the weaving of "signature pedagogies" throughout overarching program frameworks. A modern signature pedagogy within science teacher education is the integration of technology with science area content and effective pedagogy. In this article the author reports an action research study aimed toward promoting the "scholarship of teaching" of pre-service teachers through articulating changes in their maturing perceptions of the integrated relationship between technological, pedagogical, and science content knowledge. © 2012 Taylor and Francis Group, LLC.

Kumar A.,University of Manitoba
Journal of Thoracic Disease | Year: 2011

The 2009 H1N1 influenza A virus that has targeted not only those with chronic medical illness, the very young and old, but also a large segment of the patient population that has previously been afforded relative protection - those who are young, generally healthy, and immune naive. The illness is mild in most, but results in hospitalization and severe ARDS in an important minority. Among those who become critically ill, 20-40% will die, predominantly of severe hypoxic respiratory failure. However, and potentially in part due to the young age of those affected, intensive care with aggressive oxygenation support will allow most people to recover. The volume of patients infected and with critical illness placed substantial strain on the capacity of the health care system and critical care most specifically. Despite this, the 2009 pandemic has engaged our specialty and highlighted its importance like no other. Thus far, the national and global critical care response has been brisk, collaborative and helpful - not only for this pandemic, but for subsequent challenges in years ahead. © 2011 Pioneer Bioscience Publishing Company.

Lu X.,Nanyang Technological University | Wang P.,Nanyang Technological University | Niyato D.,Nanyang Technological University | Hossain E.,University of Manitoba
IEEE Wireless Communications | Year: 2014

Spectrum efficiency and energy efficiency are two critical issues in designing wireless networks. Through dynamic spectrum access, cognitive radios can improve the spectrum efficiency and capacity of wireless networks. On the other hand radio frequency (RF) energy harvesting has emerged as a promising technique to supply energy to wireless networks and thereby increase their energy efficiency. Therefore, to achieve both spectrum and energy efficiencies, the secondary users in a cognitive radio network (CRN) can be equipped with the RF energy harvesting capability, and such a network can be referred to as an RF-powered cognitive radio network. In this article we provide an overview of the RF-powered CRNs and discuss the challenges that arise for dynamic spectrum access in these networks. Focusing on the trade-off among spectrum sensing, data transmission, and RF energy harvesting, we then discuss the dynamic channel selection problem in a multi-channel RF-powered CRN. In the RF-powered CRN a secondary user can adaptively select a channel to transmit data when the channel is not occupied by any primary user. Alternatively, the secondary user can harvest RF energy for data transmission if the channel is occupied. The optimal channel selection policy of the secondary user can be obtained by formulating a Markov decision process (MDP) problem. We present some numerical results obtained by solving this MDP problem. © 2002-2012 IEEE.

Song L.,Peking University | Niyato D.,Nanyang Technological University | Han Z.,University of Houston | Hossain E.,University of Manitoba
IEEE Wireless Communications | Year: 2014

Device-to-device communication underlaying cellular networks allows mobile devices such as smartphones and tablets to use the licensed spectrum allocated to cellular services for direct peer-to-peer transmission. D2D communication can use either one-hop transmission (i.e. D2D direct communication) or multi-hop clusterbased transmission (i.e. in D2D local area networks). The D2D devices can compete or cooperate with each other to reuse the radio resources in D2D networks. Therefore, resource allocation and access for D2D communication can be treated as games. The theories behind these games provide a variety of mathematical tools to effectively model and analyze the individual or group behaviors of D2D users. In addition, game models can provide distributed solutions to the resource allocation problems for D2D communication. The aim of this article is to demonstrate the applications of game-theoretic models to study the radio resource allocation issues in D2D communication. The article also outlines several key open research directions. © 2002-2012 IEEE.

Elsawy H.,King Abdullah University of Science and Technology | Hossain E.,University of Manitoba
IEEE Transactions on Wireless Communications | Year: 2014

Using stochastic geometry, we develop a tractable uplink modeling paradigm for outage probability and spectral efficiency in both single and multi-tier cellular wireless networks. The analysis accounts for per user equipment (UE) power control as well as the maximum power limitations for UEs. More specifically, for interference mitigation and robust uplink communication, each UE is required to control its transmit power such that the average received signal power at its serving base station (BS) is equal to a certain threshold ρo. Due to the limited transmit power, the UEs employ a truncated channel inversion power control policy with a cutoff threshold of ρo. We show that there exists a transfer point in the uplink system performance that depends on the following tuple: BS intensity λ, maximum transmit power of UEs Pu, and ρo. That is, when Pu is a tight operational constraint with respect to (w.r.t.) λ and ρo, the uplink outage probability and spectral efficiency highly depend on the values of λ and ρo. In this case, there exists an optimal cutoff threshold ρ*o, which depends on the system parameters, that minimizes the outage probability. On the other hand, when Pu is not a binding operational constraint w.r.t. λ and ρo, the uplink outage probability and spectral efficiency become independent of λ and ρo. We obtain approximate yet accurate simple expressions for outage probability and spectral efficiency, which reduce to closed forms in some special cases. © 2002-2012 IEEE.

Choi K.W.,University of Manitoba
IEEE Transactions on Vehicular Technology | Year: 2010

A cognitive radio (CR) system exploits spectrum bands that primary users (PUs) are licensed to use. The CR performs channel sensing to find spectrum opportunities. Conventional periodic sensing schemes require a long sensing time to detect a weak signal from the PU with fast channel-usage variation. Since the CR network should be quiet during a sensing period, a long sensing time results in low spectrum utilization. To improve spectrum utilization, we propose a novel sensing scheme that adaptively decides whether to sense the channel or to transmit the user data based on previous sensing results. The simulation results show that the proposed scheme significantly outperforms the conventional scheme. © 2010 IEEE.

Khazaei H.,University of Manitoba | Misic J.,Ryerson University | Misic V.B.,Ryerson University
IEEE Transactions on Parallel and Distributed Systems | Year: 2012

Successful development of cloud computing paradigm necessitates accurate performance evaluation of cloud data centers. As exact modeling of cloud centers is not feasible due to the nature of cloud centers and diversity of user requests, we describe a novel approximate analytical model for performance evaluation of cloud server farms and solve it to obtain accurate estimation of the complete probability distribution of the request response time and other important performance indicators. The model allows cloud operators to determine the relationship between the number of servers and input buffer size, on one side, and the performance indicators such as mean number of tasks in the system, blocking probability, and probability that a task will obtain immediate service, on the other. © 1990-2012 IEEE.

Bohm E.R.,University of Manitoba
Journal of Arthroplasty | Year: 2010

This study was undertaken to investigate the impact of total hip arthroplasty on a patient's work ability. Fifty-four patients who were in the workforce completed a questionnaire 1 year after total hip arthroplasty. Thirty-eight (86%) of 44 patients working preoperatively were working 1 year after surgery, whereas only 2 (20%) of 10 patients who were not working preoperatively resumed work. Those who resumed work were younger and reported better Oxford-12 and physical function scores. Patients who resumed working had improvements in their ability to meet workplace physical demands and in productivity. Total hip arthroplasty has positive effects on work capacity in patients who return to work. To help patients remain in the workforce, surgery should be undertaken before a patient's hip dysfunction forces them off work. © 2010 Elsevier Inc. All rights reserved.

OBJECTIVE:: To investigate the effect of leg-focused strength training on the jump-landing mechanics of young female athletes. DESIGN:: Single-blind, randomized controlled clinical trial. SETTING:: University-based training program. PARTICIPANTS:: Forty female athletes, 10 to 14 years old, were randomly allocated to intervention or active control. INTERVENTIONS:: Twice weekly training was performed by the leg strengthening group [intervention group (IG); n = 19] and the active control group (CG; n = 17), for 12 weeks. Control group participants performed upper body strengthening exercises. MAIN OUTCOME MEASURE:: Jump-landing performance was assessed by a blinded observer using the Landing Error Scoring System (LESS). RESULTS:: There was no difference between the IG and CG postintervention (IG mean LESS score 6.0 ± SD 1.8 vs CG mean 6.1 ± SD 1.8; P = 0.85). CONCLUSIONS:: Strength training of the legs does not seem to improve jump-landing abilities in young female athletes compared with active controls who strength-trained their arms. CLINICAL RELEVANCE:: Leg strengthening may not provide an advantage over arm strengthening for improving jump-landing movement patterns in young female athletes. This has implications for the design of conditioning programs if injury prevention is a goal. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Leslie W.D.,University of Manitoba | Rubin M.R.,Columbia University | Schwartz A.V.,University of California at San Francisco | Kanis J.A.,University of Sheffield
Journal of Bone and Mineral Research | Year: 2012

There is a growing body of research showing that diabetes is an independent risk factor for fracture. Type 2 diabetes (T2D), which predominates in older individuals and is increasing globally as a consequence of the obesity epidemic, is associated with normal or even increased dual-energy x-ray absorptiometry (DXA)-derived areal bone mineral density (BMD). Therefore, the paradoxical increase in fracture risk has led to the hypothesis that there are diabetes-associated alterations in material and structural properties. An overly glycated collagen matrix, confounded by a low turnover state, in the setting of subtle cortical abnormalities, may lead to compromised biomechanical competence. In current clinical practice, because BMD is central to fracture prediction, a consequence of this paradox is a lack of suitable methods, including FRAX, to predict fracture risk in older adults with T2D. The option of adding diabetes to the FRAX algorithm is appealing but requires additional data from large population-based cohorts. The need for improved methods for identification of fracture in older adults with T2D is an important priority for osteoporosis research. © 2012 American Society for Bone and Mineral Research.

Brownridge D.A.,University of Manitoba
Australian and New Zealand Journal of Criminology | Year: 2010

Using a large-scale representative sample of Canada collected in 1999, this study examined Aboriginal men's elevated risk for violent victimization relative to non-Aboriginal men. Aboriginal men reported about 2.5 to 3.5 times the risk of intimate partner violence victimisation compared to non-Aboriginal men. Aboriginal men's elevated risk of violence was greatest on some of the most severe forms of violence and appeared to be due to their relatively higher levels of unemployment and relatively younger average age. While future research is needed to disentangle the complex interplay of colonisation and risk factors for understanding Aboriginal peoples' elevated risk of intimate partner violence victimisation, the current study demonstrates that gender is also worthy of consideration.

Apalkov V.M.,Georgia State University | Chakraborty T.,University of Manitoba
Physical Review Letters | Year: 2011

Here, we show that the incompressible Pfaffian state originally proposed for the 52 fractional quantum Hall states in conventional two-dimensional electron systems can actually be found in a bilayer graphene at one of the Landau levels. The properties and stability of the Pfaffian state at this special Landau level strongly depend on the magnetic field strength. The graphene system shows a transition from the incompressible to a compressible state with increasing magnetic field. At a finite magnetic field of ∼10T, the Pfaffian state in bilayer graphene becomes more stable than its counterpart in conventional electron systems. © 2011 American Physical Society.

Apalkov V.M.,Georgia State University | Chakraborty T.,University of Manitoba
Physical Review Letters | Year: 2011

We study the fractional quantum Hall states on the surface of a topological insulator thin film in an external magnetic field, where the Dirac fermion nature of the charge carriers have been experimentally established only recently. Our studies indicate that the fractional quantum Hall states should indeed be observable in the surface Landau levels of a topological insulator. The strength of the effect will however be different, compared to that in graphene, due to the finite thickness of the topological insulator film and due to the admixture of Landau levels of the two surfaces of the film. At a small film thickness, that mixture results in a strongly nonmonotonic dependence of the excitation gap on the film thickness. At a large enough thickness of the film, the excitation gap in the lowest two Landau levels are comparable in strength. © 2011 American Physical Society.

PURPOSE OF REVIEW: Of the idiopathic interstitial pneumonias, the differentiation between idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonitis (NSIP) raises considerable diagnostic challenges, as their clinical presentations share many overlapping features. IPF is a fibrosing pneumonia of unknown cause, showing a histologic pattern of usual interstitial pneumonia (UIP), and has a poorer prognosis than does NSIP. This review examines whether the radiographic features of IFP and NSIP as assessed by high-resolution computed tomography (HRCT) can be used to distinguish between these two entities. RECENT FINDINGS: The diagnostic accuracy of HRCT for UIP and NSIP has been reported to be approximately 70 in various studies. Disagreement between the HRCT diagnosis and the histologic diagnosis occurs in approximately one-third of the cases. The predominant feature of honeycombing on HRCT yields a specificity of approximately 95 and sensitivity of approximately 40 for UIP. In contrast, a predominant feature of ground glass opacities (GGOs) gives a sensitivity of approximately 95 and specificity of approximately 40 for NSIP. SUMMARY: The finding of honeycombing as the predominant HRCT feature suggests the diagnosis of UIP and may exclude the need for biopsy. Predominant features of GGOs are not specific enough to distinguish between NSIP and UIP. Copyright © 2012 Lippincott Williams & Wilkins.

Chen Y.,University of Manitoba | Munkholm L.J.,University of Aarhus | Nyord T.,University of Aarhus
Soil and Tillage Research | Year: 2012

Soil-tool interactions are at the centre of many agricultural field operations, including slurry injection. Understanding of soil-tool interaction behaviours (soil cutting forces and soil disturbance) is important for designing high performance injection tools. A discrete element model was developed to simulate a slurry injection tool (a sweep) and its interaction with soil using Particle Flow Code in Three Dimensions (PFC 3D). In the model, spherical particles with bonds and viscous damping between particles were used to simulate agricultural soil aggregates and their cohesive behaviours. To serve the model development, the sweep was tested in three different soils (coarse sand, loamy sand, and sandy loam). In the tests, soil cutting forces (draught and vertical forces) and soil disturbance characteristics (soil cross-section disturbance and surface deformation) resulting from the sweep were measured. The measured draught and vertical forces were used in calibrations of the most sensitive model parameter, particle stiffness. The calibrated particle stiffness was 0.75×10 3Nm -1 for the coarse sand, 2.75×10 3Nm -1 for the loamy sand, and 6×10 3Nm -1 for the sandy loam. The calibrated model was validated using the soil disturbance characteristics measured in those three soils. The simulations agreed well with the measurements with relative errors below 10% in most cases. © 2012 Elsevier B.V.

Domanski D.,University of Victoria | Murphy L.C.,University of Manitoba | Borchers C.H.,University of Victoria
Analytical Chemistry | Year: 2010

We have developed a phosphatase-based phosphopeptide quantitation (PPQ) method for determining phosphorylation stoichiometry in complex biological samples. This PPQ method is based on enzymatic dephosphorylation, combined with specific and accurate peptide identification and quantification by multiple reaction monitoring (MRM) with stable-isotope-labeled standard peptides. In contrast with classical MRM methods for the quantitation of phosphorylation stoichiometry, the PPQ-MRM method needs only one nonphosphorylated SIS (stable isotope-coded standard) and two analyses (one for the untreated sample and one for the phosphatase-treated sample), from which the expression and modification levels can accurately be determined. From these analyses, the percent phosphorylation can be determined. In this manuscript, we compare the PPQ-MRM method with an MRM method without phosphatase and demonstrate the application of these methods to the detection and quantitation of phosphorylation of the classic phosphorylated breast cancer biomarkers (ERα and HER2), and for phosphorylated RAF and ERK1, which also contain phosphorylation sites of biological importance. Using synthetic peptides spiked into a complex protein digest, we were able to use our PPQ-MRM method to accurately determine the total phosphorylation stoichiometry on specific peptides as well as the absolute amount of the peptide and phosphopeptide present. Analyses of samples containing ERα protein revealed that the PPQ-MRM method is capable of determining phosphorylation stoichiometry in proteins from cell lines, and is in good agreement with determinations obtained using the direct MRM approach in terms of phosphorylation and total protein amount. © 2010 American Chemical Society.

Chen J.,University of Manitoba
International journal of nanomedicine | Year: 2011

By mimicking the native extracellular matrix, electrospun nanofibrous scaffolds (ENSs) can provide both chemical and physical cues to modulate cell adherence and differentiation and to promote tissue regeneration while retaining bioresorbable and biocompatible properties. In this study, ENSs were developed to deliver multiple biomolecules by loading them into the core-sheath structure and/or by conjugating them to the nanofiber surfaces. In this work, poly(L-lactide)-poly(ethylene glycol)-NH(2) and poly(L-lactide) were emulsion electrospun into nanofibers with a core-sheath structure. A model drug, tetracycline hydrochloride, was loaded within the nanofibers. Amino and carboxyl reactive groups were then activated on the fiber surfaces using saturated water vapor exposure and base hydrolysis, respectively. These reactive groups allowed the surface of the ENS to be functionalized with two other bioactive molecules, fluorescein isothiocyanate- and rhodamine-labeled bovine serum albumins, which were used as model proteins. The ENSs were shown to retain their antimicrobial capacity after two functionalization reactions, indicating that multifunctional nanofibers can potentially be developed into functional wound dressings or periodontal membranes or used in more complicated tissue systems where multiple growth factors and anti-infection precautions are critical for the successful implantation and regeneration of tissues.

Singh S.,Mayo Medical School | Singh P.P.,Mayo Medical School | Murad M.H.,Robert d Patricia rn Center For The Science Of Health Care Delivery | Singh H.,University of Manitoba | Samadder N.J.,University of Utah
The American journal of gastroenterology | Year: 2014

We performed meta-analysis to estimate pooled prevalence, risk factors, and outcomes of interval colorectal cancers (CRCs). Systematic literature search through October 2013, identified population-based studies, reporting prevalence of interval CRCs (CRCs diagnosed within 6-36 months of colonoscopy). We estimated the pooled prevalence, patient, endoscopist, and tumor-related risk factors, as well as outcomes of interval CRCs, as compared with detected CRCs (CRCs diagnosed at or within 6 months of colonoscopy). Twelve studies reporting on 7,912 interval CRCs were included. Pooled prevalence of interval CRCs was 3.7% (95% confidence interval (CI)=2.8-4.9%). These cancers were 2.4 times more likely to arise in the proximal colon (6.5%; 95% CI=4.9-8.6%) as compared with distal colon (2.9%; 95% CI=2.0-4.2%). Patients with interval CRCs were older (age >65-70 years vs. <65-70 years: odds ratio (OR)=1.15; 95% CI=1.02-1.30), have more comorbidities (high Charlson comorbidity index: OR=2.00; 95% CI=1.77-2.27), and have diverticular disease (OR=4.25; 95% CI=2.58-7.00). There was a nonsignificant time trend of declining prevalence of interval CRCs from 4.8% in 1990s to 4.2% between 2000 and 2005 and 3.7% beyond 2005. Patients with interval CRCs were less likely to present at an advanced stage (OR=0.79; 95% CI=0.67-0.94), although there was no survival benefit. Considerable heterogeneity was observed in most of the analyses. Based on meta-analysis, approximately 1 in 27 CRCs are interval CRCs, although the confidence in these estimates is low because of the heterogeneity among the studies. These are more likely to arise in the proximal colon and are diagnosed in older patients, patients with comorbidities or diverticular disease.

Hora M.,Georgia Institute of Technology | Bapuji H.,University of Manitoba | Roth A.V.,Clemson University
Journal of Operations Management | Year: 2011

This research identifies and tests key factors that can be associated with time to recall a product. Product recalls due to safety hazards entail societal costs, such as property damage, injury, and sometimes death. For firms, the related external failure costs are many, including the costs of recalling the product, providing a remedy, meeting the legal liability, and repairing damage to the firm's reputation. The recent spate of product recalls has shifted attention from why products are recalled to why it takes so long to recall a defective product that poses a safety hazard. To address this, our research subjects to empirical scrutiny the time to recall and its relationship with recall strategies, source of the defect and supply chain position of the recalling firm. We develop and verify our conceptual arguments in the U.S. toy industry by analyzing over 500 product recalls during a 15-year period (1993-2008). The empirical results indicate that the time to recall, as measured by difference between product recall announcement date and product first sold date, is associated with (1) the recall strategy (preventive vs. reactive) adopted by the firm, (2) the type of product defect (manufacturing defect vs. design flaw), and (3) the supply chain entity that issues the recall (toy company vs. distributor vs. retailer). Our results provide cues that could trigger a firm's recognition of factors that increase the time to recall.

Niyato D.,Nanyang Technological University | Hossain E.,University of Manitoba | Wang P.,Nanyang Technological University
IEEE Transactions on Mobile Computing | Year: 2011

We consider the problem of optimal channel access to provide quality of service (QoS) for data transmission in cognitive vehicular networks. In such a network, the vehicular nodes can opportunistically access the radio channels (referred to as shared-use channels) which are allocated to licensed users. Also, they are able to reserve a channel for dedicated access (referred to as exclusive-use channel) for data transmission. A channel access management framework is developed for cluster-based communication among vehicular nodes. This framework has three components: opportunistic access to shared-use channels, reservation of exclusive-use channel, and cluster size control. A hierarchical optimization model is then developed for this framework to obtain the optimal policy. The objective of the optimization model is to maximize the utility of the vehicular nodes in a cluster and to minimize the cost of reserving exclusive-use channel while the QoS requirements of data transmission (for vehicle-to-vehicle and vehicle-to-roadside communications) are met, and also the constraint on probability of collision with licensed users is satisfied. This hierarchical optimization model comprises of two constrained Markov decision process (CMDP) formulationsone for opportunistic channel access, and the other for joint exclusive-use channel reservation and cluster size control. An algorithm is presented to solve this hierarchical optimization model. Performance evaluation results show the effectiveness of the optimal channel access management policy. The proposed optimal channel access management framework will be useful to support mobile computing and intelligent transportation system (ITS) applications in vehicular networks. © 2011 IEEE.

Rashwand S.,University of Manitoba | Misic J.,Ryerson University
IEEE Transactions on Vehicular Technology | Year: 2011

In this paper, we analyze an IEEE 802.11e enhanced distributed channel access (EDCA) based single-hop ad hoc network under bursty traffic addressing all four differentiation parameters. We investigate the performance of the network considering both nonsaturation and saturation regimes under an error-prone channel. We develop an accurate analytical model for the network and validate it with a simulation model. Our results indicate that adjusting the transmission opportunity (TXOP) limit in accordance with the burst size distribution can considerably improve the performance of the network and the burst delay, which is an important parameter for the application. Although large TXOP allocations improve the medium utilization and extend the stability region of the network, serious unfairness and security concerns due to the possibility of denial of service attacks may arise. The results also show that under bursty traffic, the TXOP limit can play an important role in helping the lower priority classes avoid starvation. © 2011 IEEE.

Choi K.W.,Seoul National University of Science and Technology | Hossain E.,University of Manitoba | Kim D.I.,Sungkyunkwan University
IEEE Transactions on Wireless Communications | Year: 2011

We propose a novel subchannel and transmission power allocation scheme for multi-cell orthogonal frequency-division multiple access (OFDMA) networks with cognitive radio (CR) functionality. The multi-cell CR-OFDMA network not only has to control the interference to the primary users (PUs) but also has to coordinate inter-cell interference in itself. The proposed scheme allocates the subchannels to the cells in a way to maximize the system capacity, while at the same time limiting the transmission power on the subchannels on which the PUs are active. We formulate this joint subchannel and transmission power allocation problem as an optimization problem. To efficiently solve the problem, we divide it into multiple subproblems by using the dual decomposition method, and present the algorithms to solve these subproblems. The resulting scheme efficiently allocates the subchannels and the transmission power in a distributed way. The simulation results show that the proposed scheme provides significant improvement over the traditional fixed subchannel allocation scheme in terms of system throughput. © 2011 IEEE.

Butler M.,University of Manitoba | Meneses-Acosta A.,Autonomous University of the State of Morelos
Applied Microbiology and Biotechnology | Year: 2012

The demand for production of glycoproteins from mammalian cell culture continues with an increased number of approvals as biopharmaceuticals for the treatment of unmet medical needs. This is particularly the case for humanized monoclonal antibodies which are the largest and fastest growing class of therapeutic pharmaceuticals. This demand has fostered efforts to improve the efficiency of production as well as to address the quality of the final product. Chinese hamster ovary cells are the predominant hosts for stable transfection and high efficiency production on a large scale. Specific productivity of recombinant glycoproteins from these cells can be expected to be above 50 pg/cell/day giving rise to culture systems with titers of around 5 g/L if appropriate fed-batch systems are employed. Cell engineering can delay the onset of programmed cell death to ensure prolonged maintenance of productive viable cells. The clinical efficacy and quality of the final product can be improved by strategic metabolic engineering. The best example of this is the targeted production of afucosylated antibodies with enhanced antibody-dependent cell cytotoxicity, an important function for use in cancer therapies. The development of culture media from non-animal sources continues and is important to ensure products of consistent quality and without the potential danger of contamination. Process efficiencies may also be improved by employing disposable bioreactors with the associated minimization of downtime. Finally, advances in downstream processing are needed to handle the increased supply of product from the bioreactor but maintaining the high purity demanded of these biopharmaceuticals. © Springer-Verlag Berlin Heidelberg 2012.

Lee W.,Inha University | Leung C.K.-S.,University of Manitoba | Lee J.J.H.,Inha University
IEEE Transactions on Industrial Electronics | Year: 2011

Due to advances in techniques for digital ecosystems and cyber engineering, users can now submit queries to search for inclusive information from different Web objects using mobile handheld devices such as smartphones in many real-life situations. As these mobile devices are not necessarily connected to the Internet all the time, users usually want to be able to get information such as e-mail, news, weather, and Web feed as soon as their mobile devices are connected to the Internet. However, these mobile devices have relatively limited resources. In this paper, we focus on mobile web navigation. Specifically, we use rooted directed trees, which enable users to access valuable information from the highly ranked and relevant Web sites, for answering user-inclusive queries. © 2009 IEEE.

Choi K.W.,Seoul National University of Science and Technology | Hossain E.,University of Manitoba | Kim D.I.,Sungkyunkwan University
IEEE Transactions on Wireless Communications | Year: 2011

We propose a novel cooperative spectrum sensing algorithm for a cognitive radio (CR) network to detect a primary user (PU) network that exhibits some degree of randomness in topology (e.g., due to mobility). We model the PU network as a random geometric network that can better describe small-scale mobile PUs. Based on this model, we formulate the random PU network detection problem in which the CR network detects the presence of a PU receiver within a given detection area. To address this problem, we propose a location-aware cooperative sensing algorithm that linearly combines multiple sensing results from secondary users (SUs) according to their geographical locations. In particular, we invoke the Fisher linear discriminant analysis to determine the linear coefficients for combining the sensing results. The simulation results show that the proposed sensing algorithm yields comparable performance to the optimal maximum likelihood (ML) detector and outperforms the existing ones, such as equal coefficient combining, OR-rule-based and AND-rule-based cooperative sensing algorithms, by a very wide margin. © 2011 IEEE.

Dakshinamurti K.,University of Manitoba
Canadian Journal of Physiology and Pharmacology | Year: 2015

A cluster of inter-related conditions such as central obesity, dyslipidemia, impaired glucose metabolism, and hypertension is referred to as Metabolic Syndrome, which is a risk factor for the development of type-2 diabetes. The micro- andmacro-vascular complications of diabetes contribute to its morbidity and mortality. In addition to its calcitropic effect, vitamin Dis a regulator of gene expression as well as cell proliferation and differentiation. Various cross-sectional and longitudinal cohortstudies have indicated a beneficial effect from vitamin D supplementation on the development of type-2 diabetes. Binding ofretinol-bound retinol-binding protein to a membrane-binding protein suppresses insulin signaling. All-trans retinoic acid, aderivative of vitamin A, reverses these effects, resulting in increased insulin sensitivity, suppression of the phosphoenolpyruvatecarboxy kinase (PEPCK) gene, and the induction of the glucokinase gene. Glucokinase and PEPCK are also regulated in oppositedirections by the vitamin biotin, acting at the transcriptional level. Biotin also regulates the synthesis of insulin by the islet ofLangerhans cells of the pancreas. The increase in advanced glycation end products (AGEs) is implicated in the initiation andprogression of diabetes-associated microvascular diseases. Benfotiamine, a derivative of thiamine, and pyridoxamine, a vitamerof vitamin B6, both have anti-AGE properties, making them valuable therapeutic adjuvants in the treatment of diabetic complications.Thus, various vitamins and their derivatives have profound therapeutic potential in the prevention and treatment of type-2 diabetes. © 2015, National Research Council of Canada. All rights reserved.

Meng J.,University of Houston | Yin W.,Rice University | Li H.,University of Tennessee at Knoxville | Hossain E.,University of Manitoba | Han Z.,University of Houston
IEEE Journal on Selected Areas in Communications | Year: 2011

Spectrum sensing, which aims at detecting spectrum holes, is the precondition for the implementation of cognitive radio (CR). Collaborative spectrum sensing among the cognitive radio nodes is expected to improve the ability of checking complete spectrum usage. Due to hardware limitations, each cognitive radio node can only sense a relatively narrow band of radio spectrum. Consequently, the available channel sensing information is far from being sufficient for precisely recognizing the wide range of unoccupied channels. Aiming at breaking this bottleneck, we propose to apply matrix completion and joint sparsity recovery to reduce sensing and transmission requirements and improve sensing results. Specifically, equipped with a frequency selective filter, each cognitive radio node senses linear combinations of multiple channel information and reports them to the fusion center, where occupied channels are then decoded from the reports by using novel matrix completion and joint sparsity recovery algorithms. As a result, the number of reports sent from the CRs to the fusion center is significantly reduced. We propose two decoding approaches, one based on matrix completion and the other based on joint sparsity recovery, both of which allow exact recovery from incomplete reports. The numerical results validate the effectiveness and robustness of our approaches. In particular, in small-scale networks, the matrix completion approach achieves exact channel detection with a number of samples no more than 50% of the number of channels in the network, while joint sparsity recovery achieves similar performance in large-scale networks. © 2006 IEEE.

Hannila S.S.,University of Manitoba
Neuroscientist | Year: 2015

At first glance, secretory leukocyte protease inhibitor (SLPI) would appear to have little relevance to the central nervous system (CNS). This serine protease inhibitor is most commonly found in mucosal fluids such as saliva and is best known for its anti-inflammatory and antimicrobial properties. It has been shown to promote wound healing by reducing expression of pro-inflammatory cytokines, and it can also inhibit bacterial growth and block HIV infection of macrophages. In the past 10 years, however, several studies have reported that SLPI is strongly up-regulated in response to CNS injury and that exogenous administration of SLPI is neuroprotective. It has also been shown that SLPI can overcome inhibition by CNS myelin and promote axonal regeneration. In this review, we will discuss these studies, examine the molecular mechanisms underlying SLPI's effects, and consider SLPI's potential for therapeutic use in cerebral ischemia, spinal cord injury, and multiple sclerosis. © The Author(s) 2014.

Leslie W.D.,University of Manitoba | Aubry-Rozier B.,University of Lausanne | Lamy O.,University of Lausanne | Hans D.,University of Lausanne
Journal of Clinical Endocrinology and Metabolism | Year: 2013

Context: Type 2 diabetes is associated with increased fracture risk but paradoxically greater bone mineral density (BMD). Trabecular bone score (TBS) is derived from the texture of the spine dual x-ray absorptiometry (DXA) image and is related to bone microarchitecture and fracture risk, providing information independent of BMD. Objective: This study evaluated the ability of lumbar spine TBS to account for increased fracture risk in diabetes. Design and Setting: We performed a retrospective cohort study using BMD results from a large clinical registry for the province of Manitoba, Canada. Patients: We included 29,407 women 50 years old and older with baseline DXA examinations, among whom 2356 had diagnosed diabetes. Main Outcome Measures: Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Health service records were assessed for incident nontraumatic major osteoporotic fractures (mean follow-up 4.7 years). Results: Diabetes was associated with higher BMD at all sites but lower lumbar spine TBS in unadjusted and adjusted models (all P<.001). The adjusted odds ratio (aOR) for a measurement in the lowest vs the highest tertile was less than 1 for BMD (all P<.001) but was increased for lumbar spine TBS [aOR 2.61, 95% confidence interval (CI) 2.30-2.97]. Major osteoporotic fractures were identified in 175 women (7.4%) with and 1493 (5.5%) without diabetes (P<.001). Lumbar spine TBS was a BMD-independent predictor of fracture and predicted fractures in those with diabetes (adjusted hazard ratio 1.27, 95% CI 1.10-1.46) and without diabetes (hazard ratio 1.31, 95% CI 1.24-1.38). The effect of diabetes on fracture was reduced when lumbar spine TBS was added to a prediction model but was paradoxically increased from adding BMD measurements. Conclusions: Lumbar spine TBS predicts osteoporotic fractures in those with diabetes, and captures a larger portion of the diabetes-associated fracture risk than BMD. Copyright © 2013 by The Endocrine Society.

Warrington R.,University of Manitoba
Immunotherapy | Year: 2010

Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. Chronic inflammation is associated with airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing, as well as variable airflow obstruction within the lung. With time, such airflow obstruction may become permanent due to remodeling. It has been treated for more than 100 years by subcutaneous immunotherapy with allergen extracts but in recent years, other forms and types of immunotherapy have been introduced. Perhaps the most successful of these to date, is sublingual immunotherapy, which has attained significant usage in European countries but has yet to make inroads into clinical practice in North America. Other mechanisms to modify the inflammatory responses of asthma have included immunotherapy with recombinant allergens, the use of allergen peptides targeting antigen-specific T cells and the administration of Toll-like receptor agonists coupled to allergen proteins. As the inflammatory responses in asthma frequently involve IgE, a modified monoclonal antibody to IgE and interfering with its binding to the IgE receptor have gained acceptance for treating severe allergic asthma. Other monoclonal antibodies or recombinant receptor antagonists are being assessed for their ability to block other contributors to the inflammatory response. Finally, attempts have been made to generate autoantibody responses to cytokines implicated in asthma. Most of these therapies aim to modify or inhibit the so-called Th 2 immune response, which is implicated in many forms of asthma, or to inhibit cytokines involved in these responses. However, an added benefit of classical immunotherapy seems to be the ability to prevent the allergic progression to new sensitivities and new forms of allergic disease. © 2010 Future Medicine Ltd.

Erickson J.,University of Manitoba | Johnson G.M.,Curtin University Australia
Canadian Journal on Aging | Year: 2011

An aging population is best served by social, personal, and health support focused on maintaining and maximizing personal independence. The Internet affords numerous opportunities for individuals of all ages to communicate, access information, and engage in recreational activities. A community-based sample of 122 adults over 60 years of age completed a questionnaire which assessed three clusters of characteristics: (a) frequency and patterns of Internet use, (b) well-being (loneliness, life satisfaction, self-efficacy, social support, and depression), and (c) demographics (age, income, education). Significant correlations emerged between the three clusters of measured variables. Controlling for demographic differences, Internet use and self-efficacy remained significantly related. Among the sample of older adults, individuals who used the Internet more had higher perceptions of self-efficacy than those who used the Internet rarely or not at all. © 2011 Canadian Association on Gerontology.

Appolinario C.M.,Sao Paulo State University | Jackson A.C.,University of Manitoba
Antiviral Therapy | Year: 2015

Human rabies is virtually always fatal despite numerous attempts at aggressive therapy. Most survivors received one or more doses of rabies vaccine prior to the onset of the disease. The Milwaukee Protocol has proved to be ineffective for rabies and should no longer be used. New approaches are needed and an improved understanding of basic mechanisms responsible for the clinical disease in rabies may prove to be useful for the development of novel therapeutic approaches. Antiviral therapy is thought to be an important component of combination therapy for the management of human rabies, and immunotherapy and neuroprotective therapy should also be strongly considered. There are many important issues for consideration regarding drug delivery to the central nervous system in rabies, which are in part related to the presence of the blood-brain barrier and also the blood-spinal cord barrier. Ribavirin and interferon-α have proved to be disappointing agents for the therapy of rabies. There is insufficient evidence to support the continued use of ketamine or amantadine for the therapy of rabies. Minocycline or corticosteroids should not be used because of concerns about aggravating the disease. A variety of new antiviral agents are under development and evaluation, including favipiravir, RNA interference (for example, small interfering [si]RNAs) and novel targeted approaches, including interference with viral capsid assembly and viral egress. © 2015 International Medical Press.

Roksandic M.,University of Winnipeg | Armstrong S.D.,University of Manitoba
American Journal of Physical Anthropology | Year: 2011

Paleodemography, the study of demographic parameters of past human populations, relies on assumptions including biological uniformitarianism, stationary populations, and the ability to determine point age estimates from skeletal material. These assumptions have been widely criticized in the literature and various solutions have been proposed. The majority of these solutions rely on statistical modeling, and have not seen widespread application. Most bioarchaeologists recognize that our ability to assess chronological age is inherently limited, and have instead resorted to large, qualitative, age categories. However, there has been little attempt in the literature to systematize and define the stages of development and ageing used in bioarchaeology. We propose that stages should be based in the human life history pattern, and their skeletal markers should have easily defined and clear endpoints. In addition to a standard five-stage developmental model based on the human life history pattern, current among human biologists, we suggest divisions within the adult stage that recognize the specific nature of skeletal samples. We therefore propose the following eight stages recognizable in human skeletal development and senescence: infancy, early childhood, late childhood, adolescence, young adulthood, full adulthood, mature adulthood, and senile adulthood. Striving toward a better prediction of chronological ages will remain important and could eventually help us understand to what extent past societies differed in the timing of these life stages. Furthermore, paleodemographers should try to develop methods that rely on the type of age information accessible from the skeletal material, which uses life stages, rather than point age estimates. Copyright © 2011 Wiley-Liss, Inc.

The macronutrient composition and the quality of protein of hemp seed and products derived from hemp seed grown in Western Canada were determined. Thirty samples of hemp products (minimum 500 g), including whole hemp seed, hemp seed meal from cold-press expelling, dehulled, or shelled, hemp seed and hemp seed hulls, were obtained from commercial sources. Proximate analysis, including crude protein (% CP), crude fat (% fat) and fiber, as well as full amino acid profiles, were determined for all samples. Protein digestibility-corrected amino acid score (PDCAAS) measurements, using a rat bioassay for protein digestibility and the FAO/WHO amino acid requirement of children (2-5 years of age) as reference, were conducted on subsets of hemp products. Mean (±SD) percentage CP and fat were 24.0(2.1) and 30.4(2.7) for whole hemp seed, 40.7(8.8) and 10.2(2.1) for hemp seed meal, and 35.9(3.6) and 46.7(5.0) for dehulled hemp seed. The percentage protein digestibility and PDCAAS values were 84.1-86.2 and 49-53% for whole hemp seed, 90.8-97.5 and 46-51% for hemp seed meal, and 83.5-92.1 and 63-66% for dehulled hemp seed. Lysine was the first limiting amino acid in all products. Removal of the hull fraction improved protein digestibility and the resultant PDCAAS value. The current results provide reference data in support of protein claims for hemp seed products and provide evidence that hemp proteins have a PDCAAS equal to or greater than certain grains, nuts, and some pulses.

Kumar A.,University of Manitoba | Kumar A.,Rutgers University
Journal of Antimicrobial Chemotherapy | Year: 2011

The need for early antimicrobial therapy is well established for life-threatening bacterial and fungal infections including meningitis and sepsis/septic shock. However, a link between the outcome of serious viral infections and delays in antiviral therapy is not as well recognized. Recently, with the occurrence of the influenza A/H1N1 pandemic of 2009, a large body of data regarding this issue has become available. Studies analysing data from this pandemic have consistently shown that delays in initiation of antiviral therapy following symptom onset are significantly associated with disease severity and death. Optimal survival and minimal disease severity appear to result when antivirals are started as soon as possible after symptom onset. © The Author 2011. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

Rasti M.,Amirkabir University of Technology | Hossain E.,University of Manitoba
IEEE Transactions on Wireless Communications | Year: 2013

A distributed priority-based power and admission control algorithm is presented to address the priority-based gradual removal problem in cellular wireless networks. We assume that there exist two classes of priority for users (high-priority users versus low-priority users) and minimal number of low-priority users should be gradually removed, subject to the constraint that all high-priority users are supported with their target signal-to-interference- plus-noise ratios (SINRs) which is assumed feasible. In our proposed algorithm, each high-priority user rigidly tracks its target-SINR by employing the conventional target-SINR tracking power control algorithm, and each transmitting low-priority user tracks its target-SINR as long as its required transmit power is below a threshold, otherwise it temporarily removes itself. Each removed low-priority user resumes its transmission if the required transmit power to reach its target-SINR goes below a given threshold which is different from the former. Of these two thresholds, whose values are analytically obtained, the former is provided by the base station and the latter is obtained in a distributed manner as a function of the former. We show that the distributed power-update function corresponding to our proposed algorithm has at least one fixed-point which is not unique in general. The convergence point, where our proposed algorithm potentially converges to, depends on initial transmit power levels of users. We also show that our proposed algorithm, at each of its fixed-points, not only provides all high-priority users with their (feasible) target-SINRs but also guarantees that no low-priority user is erroneously removed (i.e., no additional low priority user can be supported along with currently supported users). Furthermore, for the special case of tracking a common target-SINR by all low-priority users, we show that our proposed algorithm minimizes the outage-ratio of low-priority users subject to zero-outage-ratio of high-priority users. Simulation results confirm our analytical developments and show that our proposed priority-based power and admission control algorithm solves the priority-based gradual removal problem efficiently. © 2013 IEEE.

Saquib N.,Brac University | Hossain E.,University of Manitoba | Kim D.,University of Southern California
IEEE Wireless Communications | Year: 2013

Improvement of cell coverage and network capacity are two major challenges for the evolving 4G cellular wireless communication networks such as LTE-Advanced networks. In this context, hierarchical layering of cells with macro base stations coexisting with low-power and shortrange base stations (corresponding to picocells or femtocells) in a service area is considered to be an efficient solution to enhance the spectralefficiency of the network per unit area. Also, such a hierarchical cell deployment, which is referred to as a heterogeneous network, or Het-Net, provides significant improvement in the coverage of indoor and cell edge users and ensures better QoS to the users. Interference mitigation between different layers is one of the key issues that needs to be resolved for successful deployment of HetNets. To this end, fast frequency response, FFR, is considered to be an efficient intercell interference coordination technique for OFDMA-based HetNets. This article focuses on evaluating three state-of-the-art FFR deployment schemes: strict FFR, soft FFR, and FFR-3 schemes for OFDMA-based two-tier HetNets comprising macrocells overlaid with femtocells. Also, a variation of the FFR-3 scheme, which is referred to as the optimal static FFR (OSFFR) scheme, is proposed. A broad comparison among all these FFR schemes is performed by using Monte Carlo simulations considering performance metrics such as outage probability, average network sum rate, and spectral efficiency. Simulation results show that, the average gains in spectral efficiency (b/s/Hz) of the network are significantly higher for the proposed scheme when compared to the strict FFR, soft FFR, and FFR-3 schemes. © 2002-2012 IEEE.

Neufeld H.T.,University of Manitoba
Journal of Nutrition Education and Behavior | Year: 2011

Objective: To describe how Aboriginal women in an urban setting perceive dietary treatment recommendations associated with gestational diabetes mellitus (GDM). Design: Semi-structured explanatory model interviews explored Aboriginal women's illness experiences with GDM. Setting and Participants: Twenty-nine self-declared Aboriginal women who had received a diagnosis of GDM within the last 5 years in Winnipeg, Manitoba. Main Outcome Measures: Factors influencing Aboriginal women's prenatal food perceptions with GDM. Analysis: Thematic analysis was used through coding linkages and matrix queries to assist in identifying and categorizing patterns or relationships. Results: Participants associated fear, anxiety, and frustration with GDM. Emotional reactions appeared alongside negative relationships with food and other prescribed lifestyle treatments. Collectively, these results suggested that the experience of living with GDM can be overwhelming, as suggested by some of the complex factors influencing women's perceptions and reported behaviors. Discussions indicated many felt socially isolated and had a poor self-image and sense of failure resulting from ineffective GDM management practices. Conclusions and Implications: Future efforts should focus on self-efficacy and security in Aboriginal women's own interpretation of GDM, providing them with the understanding that there is potential for prevention and change. © 2011 Society for Nutrition Education and Behavior.

Blackburn A.,University of Manitoba
American Journal of Physical Anthropology | Year: 2011

The development of handedness throughout growth can be investigated by using bilateral asymmetry of the humerus as a proxy for this trait. A large skeletal sample of nonadults from English archaeological sites was examined using standard metric techniques to assess when right-sided asymmetry first appears in the human skeleton. Results of this work indicate a change in directional asymmetry during growth and development, with infants and young children exhibiting no significant asymmetry and older children and adolescents demonstrating right-sidedness. This trend is consistent with what has been observed in previous studies of upper limb asymmetry in skeletal material and behaviorally in living children, adding further strength to the premise that biomechanical forces strongly influence bilateral asymmetry in the upper limb bones. Variability in the magnitude of asymmetry between different features of the humerus was also noted. This characteristic can be explained by differing degrees of genetic canalization, with length and articular dimensions being more strongly canalized than diaphyseal properties. Copyright © 2011 Wiley-Liss, Inc.

Mark B.L.,Simon Fraser University | Vocadlo D.J.,University Institute of Health Sciences | Oliver A.,University of Manitoba
Future Microbiology | Year: 2011

A major cause of the clinical failure of broad-spectrum β-lactam antibiotics against Pseudomonas aeruginosa and many Enterobacteriaceae species are chromosomal mutations that lead to the hyperproduction of AmpC β-lactamase. These mutations typically affect proteins within the peptidoglycan (PG) recycling pathway, as well as proteins that are modulated by metabolic intermediates of this pathway. Blocking PG recycling and associated sensing mechanisms with small-molecule inhibitors holds promise as a strategy for overcoming AmpC-mediated resistance that results from the selection of mutations during β-lactam therapy, or from the direct acquisition of infections by AmpC-producing mutants. Here we report on the structural and functional biology of potential drug targets within the Gram-negative PG recycling pathway and the utility of blocking PG recycling as a means of attenuating AmpC-mediated resistance in P. aeruginosa. © 2011 Future Medicine Ltd.

Nicolle L.E.,University of Manitoba
Critical Care Clinics | Year: 2013

The urinary tract is a common source for life-threatening infections. Most patients with sepsis or septic shock from a urinary source have complicated urinary tract infection. This article explains the epidemiology, risk factors, and treatment. Effective management, appropriate collection of microbiology specimens, prompt initiation of antimicrobial therapy, source control, and supportive therapy are described. © 2013 Elsevier Inc.

OBJECTIVES:: Lifesaving early distinction of infectious systemic inflammatory response syndrome, known as “sepsis,” from noninfectious systemic inflammatory response syndrome is challenging in the ICU because of high systemic inflammatory response syndrome prevalence and lack of specific biomarkers. The purpose of this study was to use an automatic algorithm to detect systemic inflammatory response syndrome criteria (tachycardia, tachypnea, leukocytosis, and fever) in surgical ICU patients for ICU-wide systemic inflammatory response syndrome prevalence determination and evaluation of algorithm-derived systemic inflammatory response syndrome descriptors for sepsis prediction and diagnosis in a polytrauma cohort. DESIGN:: Cross-sectional descriptive study and retrospective cohort study. SETTING:: Electronic medical records of a tertiary care center’s surgical ICU, 2006–2011. PATIENTS:: All ICU admissions and consecutive polytrauma admissions. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS:: Average prevalence of conventional systemic inflammatory response syndrome (≥ 2 criteria met concomitantly) from cross-sectional application of the algorithm to all ICU patients and each minute of the study period was 43.3%. Of 256 validated polytrauma patients, 85 developed sepsis (33.2%). Three systemic inflammatory response syndrome descriptors summarized the 24 hours after admission and before therapy initiation: 1) systemic inflammatory response syndrome criteria average for systemic inflammatory response syndrome quantification over time, 2) first-to-last minute difference for trend detection, and 3) change count reflecting systemic inflammatory response syndrome criteria fluctuation. Conventional systemic inflammatory response syndrome for greater than or equal to 1 minute had 91% sensitivity and 19% specificity, whereas a systemic inflammatory response syndrome criteria average cutoff value of 1.72 had 51% sensitivity and 77% specificity for sepsis prediction. For sepsis diagnosis, systemic inflammatory response syndrome criteria average and first-to-last minute difference combined yielded 82% sensitivity and 71% specificity compared with 99% sensitivity and only 31% specificity of conventional systemic inflammatory response syndrome from a nested case-control analysis. CONCLUSIONS:: Dynamic systemic inflammatory response syndrome descriptors improved specificity of sepsis prediction and particularly diagnosis, rivaling established biomarkers, in a polytrauma cohort. They may enhance electronic sepsis surveillance once evaluated in other patient populations. Copyright © by 2016 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.

Vander Ploeg K.A.,University of Alberta | McGavock J.,University of Manitoba | Maximova K.,University of Alberta | Veugelers P.J.,University of Alberta
Pediatrics | Year: 2014

OBJECTIVES: Comprehensive school health (CSH) is a multifaceted approach to health promotion. A key objective of CSH is to foster positive health behaviors outside of school. This study examined the 2-year change in physical activity during and after school among students participating in a CSH intervention in Edmonton, Alberta, Canada. METHODS: This was a quasi-experimental, pre-post trial with a parallel, nonequivalent control group. Intervention schools had to be located in socioeconomically disadvantaged neighborhoods. In the spring of 2009 and 2011, pedometer recordings (7 full days) and demographic data were collected from cross-sectional samples of fifth grade students from 10 intervention schools and 20 comparison schools. A total of 1157 students participated in the study. Analyses were adjusted for potential confounders and the clustered design. RESULTS: Relative to 2009, children in 2011 were more active on schools days (1172 steps per day; P < .001) and on weekends (1450 steps per day; P < .001). However, the increase in mean steps between 2009 and 2011 was greater in CSH intervention schools than in comparison schools (school days: 1221 steps per day; P = .009; weekends: 2001 steps per day; P = .005). These increases remained significant after adjusting for gender and overweight status. CONCLUSIONS: These findings provide evidence of the effectiveness of CSH to affect children's physical activity during and outside of school. Results of this study justify broader implementation of effective CSH interventions for physical activity promotion and obesity prevention in the long term. Copyright © 2014 by the American Academy of Pediatrics.

Tarnoczi T.,University of Manitoba
Mitigation and Adaptation Strategies for Global Change | Year: 2011

Agricultural production in the Canadian Prairies is expected to be negatively affected as climate change projections for the region indicate warmer temperatures, greater incidence and severity of extreme weather events, and reduced water availability and soil moisture. To understand climate change adaption, it is important to explore the learning process that underlies farmer's adaptation practices in the region. Prairie farmers' learning was analyzed using Transformative Learning Theory whereby learning is categorized into three types: instrumental, communicative, and transformative. All producers learned instrumentally to some degree, but farmers who placed less emphasis on maximizing economic returns generally showed secondary learning outcomes correlating economic and environmental benefits. Communicative learning was mainly limited to producer-producer dialogue to the exclusion of other organizational and institutional players in the agricultural system. Critical reflection was explored as an important precursor to transformative learning. Strong evidence of transformative learning was rare (observed in 11% of farmers), but indicators of transformative learning were diverse and was observed in 43% of farmers. Transformative learning is believed to be important for flexible decision-making and autonomous thinking, making it advantageous for responding to changing environmental conditions. The analysis shows that a large number of information sources, and communication of information in an experiential and observable way, is conducive to transformative learning. Adaptation to environmental uncertainty, resulting from changing climatic conditions, may be most effectively dealt with when individual farmers undergo transformative learning whereby underlying assumptions that govern actions, values, and claims to knowledge are questioned. © 2010 Springer Science+Business Media B.V.

Duan W.H.,Monash University | Gong K.,Monash University | Wang Q.,University of Manitoba
Carbon | Year: 2011

The initiation and development of wrinkles in a single layer graphene sheet subjected to in-plane shear displacements are investigated. The dependence of the wavelength and amplitude of wrinkles on the applied shear displacements is explicitly obtained with molecular mechanics simulations. A continuum model is developed for the characteristics of the wrinkles which show that the wrinkle wavelength decreases with an increase in shear loading, while the amplitude of the wrinkles is found to initially increase and then become stable. The propagation and growth process of the wrinkles in the sheet is elucidated. It is expected that the research could promote applications of graphenes in the transportation of biological systems, separation science, and the development of the fluidic electronics. © 2011 Elsevier Ltd. All rights reserved.

Duan W.H.,Monash University | Wang Q.,University of Manitoba | Collins F.,Monash University
Chemical Science | Year: 2011

Dispersion of carbon nanotubes with sodium dodecyl sulfate (SDS) surfactant is reported by molecular mechanics simulations from an energy perspective. The interaction energy of carbon nanotubes in a tube bundle is first calculated to estimate the force sufficient to separate it from the bundle. The binding energy between increasing numbers of SDS molecules with a carbon nanotube is next estimated to identify the threshold number of surfactant molecules for a possible dispersion. With the help of ultrasonication, a sufficient number of SDS molecules are found to penetrate into an initial gap between a single tube and other nanotubes in the bundle. Owing to further congregation of the surfactants at the gap site, the gap becomes enlarged until complete dispersion. In addition to the dispersion observation in view of the interaction and binding energy perspectives, four congregation processes were identified to reveal the aggregation morphologies of SDS surfactants on the surface of carbon nanotubes as well as the effect of diameter of a carbon nanotube on the adsorption density. © The Royal Society of Chemistry 2011.

Farquhar J.,University of Maryland University College | Zerkle A.L.,University of Maryland University College | Bekker A.,University of Manitoba
Photosynthesis Research | Year: 2011

This article examines the geological evidence for the rise of atmospheric oxygen and the origin of oxygenic photosynthesis. The evidence for the rise of atmospheric oxygen places a minimum time constraint before which oxygenic photosynthesis must have developed, and was subsequently established as the primary control on the atmospheric oxygen level. The geological evidence places the global rise of atmospheric oxygen, termed the Great Oxidation Event (GOE), between ∼ 2.45 and ∼ 2.32 Ga, and it is captured within the Duitschland Formation, which shows a transition from mass-independent to mass-dependent sulfur isotope fractionation. The rise of atmospheric oxygen during this interval is closely associated with a number of environmental changes, such as glaciations and intense continental weathering, and led to dramatic changes in the oxidation state of the ocean and the seawater inventory of transition elements. There are other features of the geologic record predating the GOE by as much as 200-300 million years, perhaps extending as far back as the Mesoarchean-Neoarchean boundary at 2.8 Ga, that suggest the presence of low level, transient or local, oxygenation. If verified, these features would not only imply an earlier origin for oxygenic photosynthesis, but also require a mechanism to decouple oxygen production from oxidation of Earth's surface environments. Most hypotheses for the GOE suggest that oxygen production by oxygenic photosynthesis is a precondition for the rise of oxygen, but that a synchronous change in atmospheric oxygen level is not required by the onset of this oxygen source. The potential lag-time in the response of Earth surface environments is related to the way that oxygen sinks, such as reduced Fe and sulfur compounds, respond to oxygen production. Changes in oxygen level imply an imbalance in the sources and sinks for oxygen. Changes in the cycling of oxygen have occurred at various times before and after the GOE, and do not appear to require corresponding changes in the intensity of oxygenic photosynthesis. The available geological constraints for these changes do not, however, disallow a direct role for this metabolism. The geological evidence for early oxygen and hypotheses for the controls on oxygen level are the basis for the interpretation of photosynthetic oxygen production as examined in this review. © Springer Science+Business Media B.V. 2010.

Nicolle L.E.,University of Manitoba
Current Infectious Disease Reports | Year: 2011

Urinary tract infection remains a common problem for many populations. Recent studies have expanded our understanding of the host innate immune response and its role in the familial association observed for recurrent uncomplicated urinary tract infection in healthy women. Therapeutic management for uncomplicated infection has been compromised by increasing antimicrobial resistance, particularly global dissemination of the CTXM-15 extended spectrum β-lactamase (ESBL) producing Escherichia coli ST-131 strain. Prevention strategies exploring non-antimicrobial approaches continue to show limited promise, and approaches to limit empiric antimicrobials are now being explored. For complicated urinary tract infection, increasing antimicrobial resistance limits therapeutic options for many patients. In addition to ESBL producing E. coli, NDM-1 E. coli and Klebsiella pneumoniae and other resistant Gram negatives, such as Acinetobacter species, are being isolated more frequently. There has been renewed interest in catheter-acquired urinary tract infection, the most common health-care associated infection, with several recent evidence-based guidelines for infection prevention available. However, technologic progress in development of adherence-resistant catheter materials remains disappointing. © 2011 Springer Science+Business Media, LLC.

Kirouac G.J.,University of Manitoba
Neuroscience and Biobehavioral Reviews | Year: 2015

This article reviews the anatomical connections of the paraventricular nucleus of the thalamus (PVT) and discusses some of the connections by which the PVT could influence behavior. The PVT receives neurochemically diverse projections from the brainstem and hypothalamus with an especially strong innervation from peptide producing neurons. Anatomical evidence is also presented which suggests that the PVT relays information from neurons involved in visceral or homeostatic functions. In turn, the PVT is a major source of projections to the nucleus accumbens, the bed nucleus of the stria terminalis and the central nucleus of the amygdala as well as the cortical areas associated with these subcortical regions. The PVT is activated by conditions and cues that produce states of arousal including those with appetitive or aversive emotional valences. The paper focuses on the potential contribution of the PVT to circadian rhythms, fear, anxiety, food intake and drug-seeking. The information in this paper highlights the potential importance of the PVT as being a component of the brain circuits that regulate reward and defensive behavior with the hope of generating more research in this relatively understudied region of the brain. © 2015 The Author.

OBJECTIVES:: Sepsis is characterized by systemic activation of inflammatory and coagulation pathways in response to infection. Recently, it was demonstrated that histones released into the circulation by dying/activated cells may contribute to sepsis pathology. Although the ability of extracellular histones to modulate the procoagulant activities of several cell types has been investigated, the influence of histones on the hemostatic functions of circulating monocytes is unknown. To address this, we (a) investigated the ability of histones to modulate the procoagulant potential of THP-1 cells and peripheral blood monocytes, and (b) examined the effects of plasmas obtained from septic patients to induce a procoagulant phenotype on monocytic cells. METHODS/RESULTS:: Tissue factor (TF) activity assays were performed on histone-treated THP-1 cells and blood monocytes. Exposure of monocytic cells to histones resulted in increases in TF activity, TF antigen, and phosphatidylserine exposure. Histones modulate the procoagulant activity via engagement of Toll-like receptors 2 and 4, and this effect was abrogated with inhibitory antibodies. Increased TF activity of histone-treated cells corresponded with enhanced thrombin generation in plasma determined by calibrated automated thrombography. Finally, TF activity was increased on monocytes exposed to plasma from septic patients, an effect that was attenuated in plasma from patients receiving unfractionated heparin (UFH). CONCLUSIONS:: Our studies suggest that increased levels of extracellular histones found in sepsis contribute to dysregulated coagulation by increasing TF activity of monocytes. These procoagulant effects can be partially ameliorated in sepsis patients receiving UFH, thereby identifying extracellular histones as a potential therapeutic target for sepsis treatment. © 2016 by the Shock Society

The internal sensation of memory, which is available only to the owner of an individual nervous system, is difficult to analyze for its basic elements of operation. We hypothesize that associative learning induces the formation of functional LINK between the postsynapses. During memory retrieval, the activation of either postsynapse re-activates the functional LINK evoking a semblance of sensory activity arriving at its opposite postsynapse, nature of which defines the basic unit of internal sensation - namely, the semblion. In neuronal networks that undergo continuous oscillatory activity at certain levels of their organization re-activation of functional LINKs is expected to induce semblions, enabling the system to continuously learn, self-organize, and demonstrate instantiation, features that can be utilized for developing artificial intelligence (AI). This paper also explains suitability of the inter-postsynaptic functional LINKs to meet the expectations of Minsky's K-lines, basic elements of a memory theory generated to develop AI and methods to replicate semblances outside the nervous system. © 2011 Vadakkan.

Leslie W.D.,University of Manitoba | Morin S.N.,McGill University
Current Opinion in Rheumatology | Year: 2014

Purpose of review: To summarize the recently published studies that provide insights into the changing epidemiology of osteoporosis and fractures. Recent findings: The main themes reviewed are fracture outcomes; trends in fractures rates; fracture risk assessment and monitoring; atypical femoral fractures; male osteoporosis; falls and physical activity; and sarcopenia, obesity, and metabolic syndrome. Summary: Osteoporotic fractures were found to have long-term consequences on excess mortality (10 years) and economic costs (5 years). The large burden of nonhip nonvertebral fractures has been underestimated. Divergent (but mostly declining) trends in fracture rates were confirmed in several cohorts from around the world. This has significant implications for healthcare planners and clinicians responsible for the care of individuals with osteoporosis, and also impacts on the calibration of fracture prediction tools. Although fracture prediction tools differ in their complexity, performance characteristics are similar when applied to the general population. Large, high-quality comparative studies with different case mixes are needed. Fracture probability does not appear to be responsive enough to support goal-directed treatment at this time. A consensus on the diagnosis of osteoporosis in men has emerged, based upon the same absolute bone density cutoff for both men and women. Finally, a plethora of new data highlight the importance of falls, physical activity, and body composition as contributors to skeletal health. © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Vahedi A.,Red River College | Gorczyca B.,University of Manitoba
Water Research | Year: 2014

A number of different flocculation mechanisms are involved in the formation of chemical coagulation flocs. Consequently, two flocs with the same size may have been formed by different mechanisms of aggregation and therefore have different arrangement of primary particles. As a result, two flocs with the same size may have different masses or mass distributions and therefore, different settling velocities. Although the correct estimation of the floc mass and density is critical for the development of the floc settling model, none of the suggested floc settling models incorporate the information on mass distribution and variable density of flocs. A probability-based method is used to determine the floc fractal dimensions on floc images. The results demonstrated that flocs formed in lime softening coagulation are multifractal. The multifractal spectra indicated the existence of a multiple fractal dimensions as opposed to the unique box-counting dimension which is a morphology-based fractal dimensions typically introduced into the Stokes' Law. These fractal dimensions may provide information on the flocs' aggregation mechanism, floc's structure, and the distribution of mass inside the floc. More research is required to investigate how to utilize the information obtained from the multifractal spectra to incorporate the variable floc density and nonhomogeneous mass distribution of flocs into the floc settling models. © 2014 Elsevier Ltd.

A detailed understanding of the processes and interactions within biological communities is needed to describe and predict the biological consequences of climate change. Global warming may affect biological communities at specific sites through changes in the species composition that follow changes in range, or through altered food web interactions caused by changes in phenology or behaviour. We describe the demographic consequences for a colonial nesting seabird, the Thick-billed Murre (Uria lomvia), of exceptionally intense mosquito parasitism and predation by polar bears in a particular year. Increases in mosquito parasitism and bear predation are changes in behaviour rather than changes in range, and both caused unusual adult mortality and reproductive failure in Thick-billed Murres. In the case of adult mortality, the effects of predation and parasitism were complementary, whereas in the case of reproductive failure, most birds affected by parasitism would in any case have subsequently lost their eggs to bear predation. The mosquito and bear activities had the secondary result of redirecting the attention of gulls and foxes, the usual predators of murre eggs, towards scavenging carcasses and preying on eggs exposed by birds deserting their ledges. This diversion reduced the impact of gulls and foxes on the murres and altered the spatial configuration of predation risk. Our observations emphasize the difficulty faced by ecologists in predicting the consequences of global warming even for simple and relatively well-studied ecosystems. Moreover, the net effect of combined parasitism and predation was much greater than reported previously, reducing overall colony productivity by 20% and increasing adult mortality by 20%. If this effect happens every year, it will have population consequences. © The Arctic Institute of North America.

Sharafi M.,University of Manitoba | ELMekkawy T.Y.,Qatar University
Renewable Energy | Year: 2014

Recently, the increasing energy demand has caused dramatic consumption of fossil fuels and unavoidable raising energy prices. Moreover, environmental effect of fossil fuel led to the need of using renewable energy (RE) to meet the rising energy demand. Unpredictability and the high cost of the renewable energy technologies are the main challenges of renewable energy usage. In this context, the integration of renewable energy sources to meet the energy demand of a given area is a promising scenario to overcome the RE challenges. In this study, a novel approach is proposed for optimal design of hybrid renewable energy systems (HRES) including various generators and storage devices. The ε-constraint method has been applied to minimize simultaneously the total cost of the system, unmet load, and fuel emission. A particle swarm optimization (PSO)-simulation based approach has been used to tackle the multi-objective optimization problem. The proposed approach has been tested on a case study of an HRES system that includes wind turbine, photovoltaic (PV) panels, diesel generator, batteries, fuel cell (FC), electrolyzer and hydrogen tank. Finally, a sensitivity analysis study is performed to study the sensibility of different parameters to the developed model. © 2014.

Cao W.,University of Manitoba
RNA biology | Year: 2011

Regulation between protein kinases is critical for the establishment of signaling pathways/networks to 'orchestrate' cellular processes. Besides posttranslational phosphorylation, alternative pre-mRNA splicing is another way to control kinase properties, but splicing regulation between two kinases and the effect of resulting variants on cells has barely been explored. Here we examined the effect of the protein kinase A (PKA) pathway on the alternative splicing and variant properties of the Ca 2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) gene in B35 neuroblastoma cells. Inclusion of the exon 16 of CaMKK2 was significantly reduced by H89, a PKA selective inhibitor. Consistently, overexpressed PKA strongly promoted the exon inclusion in a CaMKK2 sequence-dependent way in splicing reporter assays. In vitro, purified CaMKKβ1 variant proteins were found to be kinase-active. In cells, they were differentially phosphorylated by PKA. In RNA interference assays, CaMKKβ1 was found to be essential for forskolin-induced neurite growth. Interestingly, overexpression of the variant without exon 16 (-E16) promoted neurite elongation while the other one (+E16) promoted neurite branching; in contrast, reduction of the latter one enhanced neurite elongation. Moreover, the variants are differentially expressed and the exon 16-containing transcripts highly enriched in the brain, particularly the cerebellum and hippocampus. Thus, PKA regulates the alternative splicing of CaMKK2 to produce variants that differentially modulate neuronal differentiation. Taken together with the many distinct variants of kinases, alternative splicing regulation likely adds another layer of modulation between protein kinases in cellular signaling networks.

Bombak A.E.,University of Manitoba
Journal of Obesity | Year: 2014

Obesity is viewed as a major public health concern, and obesity stigma is pervasive. Such marginalization renders obese persons a "special population." Weight bias arises in part due to popular sources' attribution of obesity causation to individual lifestyle factors. This may not accurately reflect the experiences of obese individuals or their perspectives on health and quality of life. A powerful role may exist for applied social scientists, such as anthropologists or sociologists, in exploring the lived and embodied experiences of this largely discredited population. This novel research may aid in public health intervention planning. Through these studies, applied social scientists could help develop a nonstigmatizing, salutogenic approach to public health that accurately reflects the health priorities of all individuals. Such an approach would call upon applied social science's strengths in investigating the mundane, problematizing the "taken for granted" and developing emic (insiders') understandings of marginalized populations. © 2014 Andrea E. Bombak.

Aladedunye F.A.,University of Manitoba
European Journal of Lipid Science and Technology | Year: 2015

Deep fat frying is an ancient process with a lot of open questions. This deceptively simple food preparation technique is immensely complicated by the stringent conditions applied during the process, coupled with the inherent lability of the frying medium and the unavoidable meddling from the food materials and other minor components. The various factors affecting frying stability and performance of oil can be broadly categorized into two groups: (1) The external factors, which include frying temperature, frying time, presence of oxygen, and type of fryers, among others, are factors that can be manipulated by the frying operators; (2) the internal or endogenous factors are oil-specific and include fatty acid composition and their distribution on triacylglycerols, and the amounts and composition of the minor components. Limiting thermo-oxidative degradation and consequently extending the useful life of frying oils often involves deliberate optimization and control of some of these factors. Available techniques for curbing thermo-oxidative decomposition of frying oils and the inherent challenges are discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tautz R.C.,TU Berlin | Shalchi A.,University of Manitoba
Journal of Geophysical Research: Space Physics | Year: 2013

Reproducing measurements of the scattering mean free paths for energetic particles propagating through the solar system has been a major problem in space physics. The pioneering work of Bieber et al. (1994) provided a theoretical explanation of such observations, which, however, was based on assumptions such as the questionable hypothesis that quasi-linear theory is correct for parallel diffusion. By employing a hybrid plasma-wave/magnetostatic turbulence model, a test-particle code is used to investigate the scattering of energetic particles. The results show excellent agreement with solar wind observations. Key PointsCosmic-ray mean-free paths are reproduced with test-particle simulationsA new hybrid plasma wave/magnetostatic models the Solar wind turbulenceThe results show excellent agreement with Palmer consensus range observations ©2013. American Geophysical Union. All Rights Reserved.

Cobb D.G.,Northwest Atlantic Fisheries Center | Galloway T.D.,University of Manitoba | Flannagan J.F.,Northwest Atlantic Fisheries Center
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2015

Effects of discharge/substrate stability relationships on the abundance, diversity, and distribution of aquatic insects were studied from 1986 to 1988 in three reaches of a small stream in the Manitoba escarpment. Substrate stability (percentage of streambed paving material at incipient motion) ranged from 80 to 20% at bankfull discharge. Eleven taxa of mayflies, 15 taxa of caddisflies, and 10 taxa of stoneflies were collected. All but a few taxa were present at all stations. Benthic insect densities were negatively correlated with increasing discharge and substrate particle movement at all stations. Regression models describing insect density in terms of substrate stability usually accounted for more variation than models describing density in terms of discharge. Insect density decreased up to 94% at the most unstable stream reach following summer and autumn spates when 8 and 12%, respectively, of the streambed paving material was at incipient motion wheres no reduction occurred in a stable riffle constructed nearby. Most insect species were highly resilient; densities and diversities returned to prespate levels during periods of low flow. Temporal and spatial aspects of substrate stability should be considered in stream insect studies, particularly in relation to disturbance. De 1986 à 1988, on a étudié les incidences des relations entre ledébitet la stabilite du substrát dans trois tronçons d'un petit cours d'eau de l'escarpement du Manitoba sur I'abondance, la diversité et la repartition des insectes aquatiques. La stabilite du substrát (soit le pourcentage de matériaux recouvrant le lit du cours d'eau en début de mouvement) variait de 80 à 20% au cours du débit à plein bord. On a recueilli 11 taxons d'éphémères, 15 „ taxons de phryganes et 10 taxons de perles; tous étaient présents, sauf quelques-uns, à toutes les stations. La densité des insectes benthiques était en corrélation négative avec un plus grand débit et un plus grand dépla- cement des particules du substrát à toutes les stations. Les modèles de régression décrivant la densité des insectes en termes de la stabilite du substrát tenaient généralement compte dune plus grande variation que les modèles décrivant la densité en termes de débit. La densité des insectes a montré une baisse allant jusqu'á 94% dans les tronçons les plus instables aprés les erues dété et dautomne, lorsque 8 et 12% respectivement des matériaux recouvrant le lit du cours d'eau commençaient à se déplacer, tandis qu'aucune baisse du genre n'a été notée dans un radier stable voisin. Laplupartdes espèces d insectes se sontfacilement adaptéesàces conditions; ainsi, leur densité et leur diversité se sont rapidement rétablies au niveau pré-crue au cours des périodes de faible débit. On devrait done tenir compte des aspects temporaux et spatiaux de la stabilité du substrát lors d'études sur les insectes peuplant au cours d'eau, en particulier en ce qui a trait aux perturbations. © 2015, National Research Council of Canada. All rights reserved.

Participation in physical activity is important for the positive development and well-being of youth. A community- academic partnership was formed to improve access to physical activity for youth in one disadvantaged community in Ottawa, Canada. After consulting this community, a new hip-hop dance intervention was implemented. Adolescents aged 11 to 16 years participated in one of two 3-month sessions. A girls-only and a boys-and-girls format were offered both sessions. This article investigates the implementation of the intervention from the perspective of the youth participants, parents, staff, and researchers. Multiple methods were used, including document review, observation, questionnaire, focus groups, and interviews. Overall, the consistency and quality of program implementation were moderately satisfactory; however, important concerns were noted and this program appeared to be only partially delivered as planned. These findings will be discussed in terms of suggestions for improving the implementation of this intervention and similar recreation programs prioritizing disadvantaged communities.

Leslie W.D.,University of Manitoba | Morin S.N.,McGill University | Lix L.M.,University of Saskatchewan
Journal of Clinical Endocrinology and Metabolism | Year: 2012

Context: There is contradictory information on whether the rate of bone mineral density(BMD) loss is an independent risk factor for osteoporotic fractures and whether this should be included in fracture prediction systems. Objective: This study was undertaken to better define rate of BMD loss as a contributor to fracture risk in routine clinical practice. Design and Setting: We performed a retrospective cohort study using a database of all clinical BMD results for the province of Manitoba, Canada. Patients: We included 4498 untreated women age 40 yr and older at the time of a second BMD test performed between April 1996 and March 2009. Main Outcome Measures: A total of 146 women with major osteoporotic fracture outcomes after the second BMD test (mean observation, 2.7 yr) and relevant covariates were identified in population- based computerized health databases. Results: Annualized percentage change in total hip BMD was no greater in fracture compared to nonfracturewomen(-0. 4±1.7 vs.-0.5±1.4; P=0.166). After adjustment for final total hip BMD, other covariates, and medication use, rate of total hip BMD change did not predict major osteoporotic fractures (hazard ratio, 0.95 per SD decrease; 95% confidence interval, 0.81-1.10). Similar results were also seen in analyses based upon change in lumbar spine and femoral neck BMD. Conclusions: We found no evidence that BMD loss, as detected during routine clinical monitoring, was a significant independent risk factor for major osteoporotic fractures. Copyright © 2012 by The Endocrine Society.

Apalkov V.M.,Georgia State University | Chakraborty T.,University of Manitoba
Solid State Communications | Year: 2014

We report on the properties of incompressible states of Dirac fermions in graphene in the presence of an anisotropic Hamiltonian and a quantizing magnetic field. We introduce the necessary formalism to incorporate the unimodular spatial metric to deal with the anisotropy in the system. The incompressible state in graphene is found to survive the anisotropy up to a critical value of the anisotropy parameter. The anisotropy also introduces two branches in the collective excitations of the corresponding Laughlin state. It strongly influences the short-range behavior of the pair-correlation functions in the incompressible ground state. © 2013 Elsevier Ltd.

Ng S.C.,Chinese University of Hong Kong | Bernstein C.N.,University of Manitoba | Vatn M.H.,University of Oslo | Lakatos P.L.,Semmelweis University | And 5 more authors.
Gut | Year: 2013

The changing epidemiology of inflammatory bowel disease (IBD) across time and geography suggests that environmental factors play a major role in modifying disease expression. Disease emergence in developing nations suggests that epidemiological evolution is related to westernisation of lifestyle and industrialisation. The strongest environmental associations identified are cigarette smoking and appendectomy, although neither alone explains the variation in incidence of IBD worldwide. Urbanisation of societies, associated with changes in diet, antibiotic use, hygiene status, microbial exposures and pollution have been implicated as potential environmental risk factors for IBD. Changes in socioeconomic status might occur differently in different geographical areas and populations and, consequently, it is important to consider the heterogeneity of risk factors applicable to the individual patient. Environmental risk factors of individual, familial, community-based, countrybased and regionally based origin may all contribute to the pathogenesis of IBD. The geographical variation of IBD provides clues for researchers to investigate possible environmental aetiological factors. The present review aims to provide an update of the literature exploring geographical variability in IBD and to explore the environmental risk factors that may account for this variability.

Hasan S.W.,Masdar Institute of Science and Technology | Elektorowicz M.,Concordia University at Montreal | Oleszkiewicz J.A.,University of Manitoba
Chemosphere | Year: 2014

Submerged membrane electro-bioreactor (SMEBR) is a new hybrid technology for wastewater treatment employing electrical field and microfiltration in a nutrient-removing activated sludge process. A pilot SMEBR system was located at the wastewater treatment plant in the City of l'Assomption (Quebec, Canada) with the objective of investigating the start-up period performance under variable organic loadings and environmental conditions with respect to effluent quality, membrane fouling, and sludge properties. The pilot SMEBR facility was fed with the raw de-gritted municipal wastewater. At steady state operation, the removal efficiencies of ammonia (as NH3+-N), phosphorus (as PO43--P), and COD were 99%, 99%, and 92%, respectively. No substantial increase in the monitored transmembrane pressure as 0.02kPad-1 was reported. The time necessary to filter 100mL of the sludge sample has decreased by 78% after treatment whilst the sludge volume index averaged 119mLg-1. Energy requirements were in the range of 1.1-1.6kWhm-3 of wastewater. It was concluded that the SMEBR is a very competitive technology when compared to conventional membrane systems as it can enhance treatment performance to an appreciable extent, remove phosphorus and reduce fouling. © 2013.

Koiter A.J.,University of Northern British Columbia | Owens P.N.,University of Northern British Columbia | Petticrew E.L.,University of Northern British Columbia | Lobb D.A.,University of Manitoba
Earth-Science Reviews | Year: 2013

Sediment fingerprinting is a technique that is increasingly being used to improve the understanding of sediment dynamics within river basins. At present, one of the main limitations of the technique is the ability to link sediment back to their sources due to the non-conservative nature of many of the sediment properties. The processes that occur between the sediment source locations and the point of collection downstream are not well understood or quantified and currently represent a black-box in the sediment fingerprinting approach. The literature on sediment fingerprinting tends to assume that there is a direct connection between sources and sinks, while much of the broader environmental sedimentology literature identifies that numerous chemical, biological and physical transformations and alterations can occur as sediment moves through the landscape. The focus of this paper is on the processes that drive particle size and organic matter selectivity and biological, geochemical and physical transformations and how understanding these processes can be used to guide sampling protocols, fingerprint selection and data interpretation. The application of statistical approaches without consideration of how unique sediment fingerprints have developed and how robust they are within the environment is a major limitation of many recent studies. This review summarises the current information, identifies areas that need further investigation and provides recommendations for sediment fingerprinting that should be considered for adoption in future studies if the full potential and utility of the approach are to be realised. © 2013 Elsevier B.V.

Baim S.,University of Miami | Leslie W.D.,University of Manitoba
Current Osteoporosis Reports | Year: 2012

Osteoporosis-related fractures (low-trauma, fragility fractures) are associated with significant morbidity, mortality, and health care expenditure worldwide. In the absence of a defining fracture, the diagnosis of osteoporosis is based on the World Health Organization's T-score criteria using central dual-energy x-ray absorptiometry (DXA). Paradoxically, the majority of those patients who will sustain a low-trauma fracture do not meet the T-score definition of osteoporosis. Conversely, younger individuals with bone density in the osteoporotic range but no other risk factors have relatively low fracture rates and yet are frequently considered candidates for osteoporosis therapies. The limited accuracy of bone density testing alone to predict fractures has led to the development of a variety of fracture assessment tools that utilize the combination of bone density and clinical risk factors to improve the prediction of low-trauma fractures. These fracture assessment tools quantitatively predict the 10-year fracture probability of hip and major osteoporosis-related fractures, and can be used to define cost-effective intervention strategies for primary and secondary fracture prevention. © Springer Science+Business Media, LLC 2012.

Skipetrov S.E.,University Grenoble alpes | Skipetrov S.E.,French National Center for Scientific Research | Page J.H.,University of Manitoba
New Journal of Physics | Year: 2016

During the last 30 years, the search for Anderson localization of light in three-dimensional (3D) disordered samples yielded a number of experimental observations that were first considered successful, then disputed by opponents, and later refuted by their authors. This includes recent results for light in TiO2 powders that Sperling et al now show to be due to fluorescence and not to Anderson localization (2016 New J. Phys. 18 013039). The difficulty of observing Anderson localization of light in 3D may be due to a number of factors: insufficient optical contrast between the components of the disordered material, near-field effects, etc. The way to overcome these difficulties may consist in using partially ordered materials, complex structured scatterers, or clouds of cold atoms in magnetic fields. © 2016 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Stajduhar K.I.,University of Victoria | Funk L.,University of Manitoba | Outcalt L.,University of Victoria
Palliative Medicine | Year: 2013

Background: Family caregivers are assuming growing responsibilities in providing care to dying family members. Supporting them is fundamental to ensure quality end-of-life care and to buffer potentially negative outcomes, although family caregivers frequently acknowledge a deficiency of information, knowledge, and skills necessary to assume the tasks involved in this care. Aim: The aim of this inquiry was to explore how family caregivers describe learning to provide care to palliative patients. Design: Secondary analysis of data from four qualitative studies (n = 156) with family caregivers of dying people. Data sources: Data included qualitative interviews with 156 family caregivers of dying people. Results: Family caregivers learn through the following processes: trial and error, actively seeking needed information and guidance, applying knowledge and skills from previous experience, and reflecting on their current experiences. Caregivers generally preferred and appreciated a supported or guided learning process that involved being shown or told by others, usually learning reactively after a crisis. Conclusions: Findings inform areas for future research to identify effective, individualized programs and interventions to support positive learning experiences for family caregivers of dying people. © The Author(s) 2013.

Woo V.,University of Manitoba
International Journal of Clinical Practice | Year: 2015

Background The availability of a dual sodium glucose co-transporter 2/dipeptidyl peptidase-4 inhibitor combination in a single-tablet combination (STC) represents a new therapeutic option for patients with type 2 diabetes. Empagliflozin/linagliptin STC has been recently approved by the US Food and Drug Administration for the treatment of type 2 diabetes mellitus (T2DM). Aim The aim of this study was to describe the latest clinical evidence on the efficacy and safety profiles of empagliflozin/linagliptin STCs in comparison with the individual components. Juxtaposition of the STC with dapagliflozin/saxagliptin combination was also presented. Results Empagliflozin/linagliptin STC given as initial therapy or on metformin background lowered mean glycated haemoglobin (HbA1c) by approximately 1.1% (mean baseline HbA1c, 8.0%). Furthermore, the STC reduced mean body weight by 2.0-3.0 kg from baseline. With the STC treatment, no confirmed incidents of hypoglycaemia were reported in drug-naïve patients; in patients taking metformin hypoglycaemia occurred at low rates which were comparable with monotherapy. Use of STCs in the treatment of T2DM can simplify drug dosing regimen, reduce pill burden and increase treatment adherence. Empagliflozin/linagliptin STC is a combination that offers potential additional benefits such as body weight loss and moderate reductions in blood pressure, without increasing risk of hypoglycaemia. Conclusion Empagliflozin/linagliptin STC appears to be a rational choice for a wide range of patients in need of multiple agents for controlling hyperglycaemia. The STC should be particularly useful in patients in whom hypoglycaemia, weight gain and treatment adherence are of concern. © 2015 The Authors. International Journal of Clinical Practice Published by John Wiley & Sons Ltd.

Stein M.B.,University of California at San Diego | Sareen J.,University of Manitoba
New England Journal of Medicine | Year: 2015

A 46-year-old married woman presents with insomnia, headaches, muscle tension, and back pain. She describes a long-term pattern of worrying about several life situations, including health, finances, and her job, and she notes increased anxiety associated with her teenager's leaving home to attend college. She drinks alcohol daily to reduce the tension and help her sleep. In reviewing her history, you note that she has visited your office many times over the past year because of physical symptoms. What do you advise?

Vriend J.,University of Manitoba | Reiter R.J.,University of Texas Health Science Center at San Antonio
Life Sciences | Year: 2014

Proteasome inhibitors and melatonin are both intimately involved in the regulation of major signal transduction proteins including p53, cyclin p27, transcription factor NF-κB, apoptotic factors Bax and Bim, caspase 3, caspase 9, anti-apoptotic factor Bcl-2, TRAIL, NRF2 and transcription factor beta-catenin. The fact that these factors are shared targets of the proteasome inhibitor bortezomib and melatonin suggests the working hypothesis that melatonin is a proteasome inhibitor. Supporting this hypothesis is the fact that melatonin shares with bortezomib a selective pro-apoptotic action in cancer cells. Furthermore, both bortezomib and melatonin increase the sensitivity of human glioma cells to TRAIL-induced apoptosis. Direct evidence for melatonin inhibition of the proteasome was recently found in human renal cancer cells. We raise the issue whether melatonin should be investigated in combination with proteasome inhibitors to reduce toxicity, to reduce drug resistance, and to enhance efficacy. This may be particularly valid for hematological malignancies in which proteasome inhibitors have been shown to be useful. Further studies are necessary to determine whether the actions of melatonin on cellular signaling pathways are due to a direct inhibitory effect on the catalytic core of the proteasome, due to an inhibitory action on the regulatory particle of the proteasome, or due to an indirect effect of melatonin on phosphorylation of signal transducing factors. © 2014 Elsevier Inc.

Chmelnitsky E.G.,University of Manitoba
The Journal of the Acoustical Society of America | Year: 2012

Classification of animal vocalizations is often done by a human observer using aural and visual analysis but more efficient, automated methods have also been utilized to reduce bias and increase reproducibility. Beluga whale, Delphinapterus leucas, calls were described from recordings collected in the summers of 2006-2008, in the Churchill River, Manitoba. Calls (n=706) were classified based on aural and visual analysis, and call characteristics were measured; calls were separated into 453 whistles (64.2%; 22 types), 183 pulsed/noisy calls (25.9%; 15 types), and 70 combined calls (9.9%; seven types). Measured parameters varied within each call type but less variation existed in pulsed and noisy call types and some combined call types than in whistles. A more efficient and repeatable hierarchical clustering method was applied to 200 randomly chosen whistles using six call characteristics as variables; twelve groups were identified. Call characteristics varied less in cluster analysis groups than in whistle types described by visual and aural analysis and results were similar to the whistle contours described. This study provided the first description of beluga calls in Hudson Bay and using two methods provides more robust interpretations and an assessment of appropriate methods for future studies.

Buhl M.,University of St. Andrews | Schreckenbach G.,University of Manitoba
Inorganic Chemistry | Year: 2010

A recently proposed pathway for the scrambling of axial (uranyl) and equatorial O atoms in [UO 2(OH) 4] 2- (1) is refined using Car-Parrinello molecular dynamics (CPMD) simulations in an explicit solvent (water) and with model counterions (NH 4 +). According to constrained CPMD/BLYP simulations and thermodynamic integration, 1 can be deprotonated to [UO 3(OH) 3] 3- with a T-shaped UO 3 group (ΔA = 7.1 kcal/mol), which in turn can undergo a solvent-assisted proton transfer via a cis-[UO 2(OH) 4] 2- OH - complex and a total overall barrier of ΔA ‡ = 12.5 kcal/mol. According to computed relative energies of trans- and cis-[UO 2(OH) 4] 2- in the gas phase and in a polarizable continuum, "pure" functionals such as BLYP underestimate this overall barrier somewhat, and estimates of ΔA ‡ ≈ 16 and 17 kcal/mol are obtained at the B3LYP and CCSD(T) levels, respectively, in excellent agreement with the experiment. © 2010 American Chemical Society.

Fernyhough P.,St Boniface Hospital Research Center | Fernyhough P.,University of Manitoba
Current Diabetes Reports | Year: 2015

Diabetic neuropathy is a dying back neurodegenerative disease of the peripheral nervous system where mitochondrial dysfunction has been implicated as an etiological factor. Diabetes (type 1 or type 2) invokes an elevation of intracellular glucose concentration simultaneously with impaired growth factor support by insulin, and this dual alteration triggers a maladaptation in metabolism of adult sensory neurons. The energy sensing pathway comprising the AMP-activated protein kinase (AMPK)/sirtuin (SIRT)/peroxisome proliferator-activated receptor-γ coactivator α (PGC-1α) signaling axis is the target of these damaging changes in nutrient levels, e.g., induction of nutrient stress, and loss of insulin-dependent growth factor support and instigates an aberrant metabolic phenotype characterized by a suppression of mitochondrial oxidative phosphorylation and shift to anaerobic glycolysis. There is discussion of how this loss of mitochondrial function and transition to overreliance on glycolysis contributes to the diminishment of collateral sprouting and axon regeneration in diabetic neuropathy in the context of the highly energy-consuming nerve growth cone. © 2015, Springer Science+Business Media New York.

Vriend J.,University of Manitoba | Reiter R.J.,University of Texas Health Science Center at San Antonio
Cellular and Molecular Life Sciences | Year: 2014

Melatonin has been widely studied for its role in photoperiodism in seasonal breeders; it is also a potent antioxidant. Ubiquitin, a protein also widespread in living cells, contributes to many cellular events, although the most well known is that of tagging proteins for destruction by the proteasome. Herein, we suggest a model in which melatonin interacts with the ubiquitin-proteasome system to regulate a variety of seemingly unrelated processes. Ubiquitin, for example, is a major regulator of central activity of thyroid hormone type 2 deiodinase; the subsequent regulation of T3 may be central to the melatonin-induced changes in seasonal reproduction and seasonal changes in metabolism. Both melatonin and ubiquitin also have important roles in protecting cells from oxidative stress. We discuss the interaction of melatonin and the ubiquitin-proteasome system in oxidative stress through regulation of the ubiquitin-activating enzyme, E1. Previous reports have shown that glutathiolation of this enzyme protects proteins from unnecessary degradation. In addition, evidence is discussed concerning the interaction of ubiquitin and melatonin in activation of the transcription factor NF-κB as well as modulating cellular levels of numerous signal transducing factors including the tumor suppressor, p53. Some of the actions of melatonin on the regulatory particle of the proteasome appear to be related to its inhibition of the calcium-dependent calmodulin kinase II, an enzyme which reportedly copurifies with proteasomes. Many of the actions of melatonin on signal transduction are similar to those of a proteasome inhibitor. While these actions of melatonin could be explained by a direct inhibitory action on the catalytic core particle of the proteasome, this has not been experimentally verified. If our hypothesis of melatonin as a general inhibitor of the ubiquitin-proteasome system is confirmed, it is predicted that more examples of this interaction will be demonstrated in a variety of tissues in which ubiquitin and melatonin co-exist. Furthermore, the hypothesis of melatonin as an inhibitor of the ubiquitin-proteasome system will be a very useful model for clinical testing of melatonin. © 2014 Springer.

Mehrad B.,University of Virginia | Clark N.M.,Loyola University | Zhanel G.G.,University of Manitoba | Lynch J.P.,Science 37
Chest | Year: 2015

Aerobic gram-negative bacilli, including the family of Enterobacteriaceae and non-lactose fermenting bacteria such as Pseudomonas and Acinetobacter species, are major causes of hospital-acquired infections. The rate of antibiotic resistance among these pathogens has accelerated dramatically in recent years and has reached pandemic scale. It is no longer uncommon to encounter gram-negative infections that are untreatable using conventional antibiotics in hospitalized patients. In this review, we provide a summary of the major classes of gram-negative bacilli and their key mechanisms of antimicrobial resistance, discuss approaches to the treatment of these diffi cult infections, and outline methods to slow the further spread of resistance mechanisms. © 2015 American College Of Chest Physicians.

Rashidian A.,University of Manitoba | Klymyshyn D.M.,University of Saskatchewan
IEEE Transactions on Antennas and Propagation | Year: 2012

As the number of resonances increases, it becomes difficult to improve and maintain the performance of dielectric resonator antennas (DRAs), over the expanded impedance bandwidth. To remove unwanted modes, adjust the frequency distance between individual modes, reduce antenna size and cross polarization, and preserve radiation patterns in a wideband configuration, a dielectric resonator antenna fed with parallel standing strips is proposed in this paper. The use of parallel standing strips provides several degrees of freedom in the design procedure to enhance the DRA characteristics. To validate the effectiveness of this approach, two DRAs with parallel standing strips were fabricated using different procedures. The antennas were tested and characterized. The measured results are in good agreement with simulation ones. A 46% size reduction was achieved for the multimode DRA. The impedance bandwidth of the proposed DRA of simple rectangular shape was over 60% with a measured gain ranging from 5.5 to 9.5 dBi. Broadside radiation patterns with fairly low cross polarizations can be maintained over the impedance bandwidth. The simulated radiation efficiency is more than 96% within the frequency band. © 2012 IEEE.

Budzelaar P.H.M.,University of Manitoba
Wiley Interdisciplinary Reviews: Computational Molecular Science | Year: 2012

Branches are an important aspect of the structure of real polyethylene. Branches can be short (Me, Et) or longer; long-chain branches (LCB, >100 carbons), in particular, are important because they can have a dramatic effect on polymer properties. In this review, we summarize mechanistic information from organometallic and computational chemistry and use this to examine the most probable sources of each type of branch. Short branches can be introduced deliberately by copolymerization with an α-olefin (possibly formed in situ from ethene). Me branches may be formed by one-carbon chain walking and propagation, and/or from insertion of an oligomer/macromer in an M-Me bond formed via chain transfer to the cocatalyst [Me 3Al or methylaluminoxane (MAO)]. Et branches are most likely formed through β-hydrogen transfer to ethene, followed immediately by reinsertion of the newly formed macromer. LCBs have usually been ascribed to reinsertion of macromers. However, certain catalysts exhibit LCB formation patterns that are hard to reconcile with this model, and a 'two-monomer' model was recently proposed to explain the observations for these systems. In this review, we present an alternative explanation (chain walking) that would fit the same facts for these catalysts. © 2011 John Wiley & Sons, Ltd.

Gupta M.,University of Manitoba
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2015

In this paper, the author investigates the effect of Raman scattering on remotely sensed suspended sediment concentration (SSC) through the analysis of various SSC retrieval models in the coastal waters (Case 2) of the Bay of Bengal. A higher Raman contribution is observed in waters containing less SSC and chlorophyll-a concentration. Tassan's model, which used three wavelengths, i.e., 490, 555, and 670 nm, is able to account for Raman contribution at three emission wavelengths. The analysis showed the highest ∼14 fraction in the computed SSC and 8.4% fraction in the reflectance (at 555 nm) due to Raman scattering. A fraction of ∼ 14 in the SSC due to Raman scattering is significant and should be addressed in SSC retrieval models. More channels (wavelengths) are required to adequately account for the Raman contribution for estimating SSC from the remote sensing reflectance. The inclusion of blue and infrared wavelengths in the empirical models of SSC retrieval is suggested as a topic of future research, because the excitation and emission do occur at these respective wavelengths. © 2014 IEEE.

Hawthorne F.C.,University of Manitoba
American Mineralogist | Year: 2015

The patterns of linkage of chemical bonds in space contain significant energetic information that may be used as the basis of a theoretical approach to the structure and chemical composition of minerals. This approach combines aspects of graph theory, bond-valence theory, and the moments approach to the electronic-energy density-of-states to interpret topological aspects of crystal structures, and allows consideration of many issues of crystal structure, mineral composition, and mineral behavior that are not addressed by established theoretical methods. The chemical composition of a mineral is controlled by the weak interaction between the structural unit and the interstitial complex. The principle of correspondence of Lewis acidity-basicity asserts that stable structures will form when the Lewisbase strength of the structural unit closely matches the Lewis-acid strength of the interstitial complex. This principle allows analysis of the factors that control the chemical compositions and aspects of the structural arrangements of minerals, and provides a mechanism to understand the relations between structure, the speciation of its constituents in aqueous solution, and its mechanism of crystallization. (H2O) groups in the structural unit limit the polymerization of the structural unit in one or more directions, controlling the polymerization of the structural unit. This is a major cause of structural diversity in oxygen-based minerals, and accounts for the systematic distribution in mineral species from the core to the surface of the Earth. The moments approach to the electronic-energy density-of-states provides a bond-topological interpretation of the energetics of a structure. When comparing structures, the most important structural differences involve the first few disparate moments of the electronic-energy density-of-states. We may classify chemical reactions according to the lowest-order moment of the electronic-energy density-ofstates that is conserved, which allows us to identify the principal structural changes that drive chemical change: (1) coordination number for discontinuous reactions, and (2) short-range order for continuous reactions. This relation between the bond topology of a structure and its enthalpy of formation from constituent oxides is indicated by a correlation between change in anion-coordination number and reduced enthalpy of formation for the reactions [6]Mgm[4]SinO(m+2n) = mMgO+nSiO2. © 2015 by Walter de Gruyter.

Brown T.A.,University of Plymouth | Belt S.T.,University of Plymouth | Tatarek A.,Polish Academy of Sciences | Mundy C.J.,University of Manitoba
Nature Communications | Year: 2014

Analysis of the organic geochemical biomarker IP 25 in marine sediments is an established method for carrying out palaeo sea ice reconstructions for the Arctic. Such reconstructions cover timescales from decades back to the early Pleistocene, and are critical for understanding past climate conditions on Earth and for informing climate prediction models. Key attributes of IP 25 include its strict association with Arctic sea ice together with its ubiquity and stability in underlying marine sediments; however, the sources of IP 25 have remained undetermined. Here we report the identification of IP 25 in three (or four) relatively minor (<5%) sea ice diatoms isolated from mixed assemblages collected from the Canadian Arctic. In contrast, IP 25 was absent in the dominant taxa. Chemical and taxonomical investigations suggest that the IP 25-containing taxa represent the majority of producers and are distributed pan-Arctic, thus establishing the widespread applicability of the IP 25 proxy for palaeo Arctic sea ice reconstruction. © 2014 Macmillan Publishers Limited.

Friesen M.R.,University of Manitoba
International Journal of Engineering Education | Year: 2010

This paper presents a case study of the development and evolution of a qualifications recognition (QR) program for immigrant engineering professionals at the University of Manitoba, Canada, within the framework of action research. Qualitative data were collected through participantobservation and through focus groups and follow-up questionnaires with participants from 2003 through 2008. The findings show the evolution of the program from a process narrowly focused on formal recognition of foreign academic credentials, to a program focused on holistic qualifications recognition goals of full professional integration, including labour market access and success, cultural understanding, professional networking, and language development. This evolution occurred within a framework of partnerships between university, regulatory body, and industry. © 2010 TEMPUS Publications.

Coulthard S.,University of Ulster | Johnson D.,University of Manitoba | McGregor J.A.,University of Sussex
Global Environmental Change | Year: 2011

The purpose of this paper is to explore the extent to which a social wellbeing approach can offer a useful way of addressing the policy challenge of reconciling poverty and environmental objectives for development policy makers. In order to provide detail from engagement with a specific policy challenge it takes as its illustrative example the global fisheries crisis. This crisis portends not only an environmental disaster but also a catastrophe for human development and for the millions of people directly dependent upon fish resources for their livelihoods and food security. The paper presents the argument for framing the policy problem using a social conception of human wellbeing, suggesting that this approach provides insights which have the potential to improve fisheries policy and governance. By broadening the scope of analysis to consider values, aspirations and motivations and by focusing on the wide range of social relationships that are integral to people achieving their wellbeing, it provides a basis for better understanding the competing interests in fisheries which generate conflict and which often undermine existing policy regimes. © 2011 Elsevier Ltd.

Tautz R.C.,TU Berlin | Shalchi A.,University of Manitoba
Physics of Plasmas | Year: 2010

In the past four decades, several nonlinear theories have been developed to describe (i) the motion of charged test particles through a turbulent magnetized plasma and (ii) the random walk of magnetic field lines. In many such theories, the so-called Corrsin independence hypothesis has been applied to enforce analytical tractability. In this note, it is shown that the Corrsin hypothesis is part of most nonlinear diffusion theories. In some cases, the Corrsin approximation is somewhat hidden, while in other cases a different name is used for the same approach. It is shown that even the researchers who criticized the application of this hypothesis have used it in their nonlinear diffusion theories. It is hoped that the present article will eliminate the recently caused confusion about the applicability and validity of the Corrsin hypothesis. © 2010 American Institute of Physics.

Berkes F.,University of Manitoba
Bulletin of Marine Science | Year: 2010

Conventional fishery management largely overlooks scale considerations and other complexities, fueling a search for alternative approaches. In the approach examined here, the starting point is that fisheries should be treated as linked social-ecological systems, leading to ecosystem-based management that explicitly includes humans in the system and recognizes the interdependent nature of social and ecological systems. Given that both ecosystems and social systems operate at multiple spatial scales, how do we make the linkages between and within levels of the governance system? I approached this objective in three steps. First, I explored institutions related to spatial management; these are rules of access control and access management, such as property rights and territorial use rights. Second, I considered levels of the institutional scale and linkages between levels that lead to multilevel governance. Third, I used the example of roving bandits to demonstrate why marine resources must be managed simultaneously at multiple levels and the importance of linkages. Even though roving bandits are not susceptible to a single solution, a diversity of approaches used together can slow them down. These include establishing property rights and territorial-use rights and building multilevel institutions from local to global that can learn from experience. Roving-bandit cases offer a number of lessons: the importance of fisher knowledge in detecting environmental change, monitoring as an essential step in governance, and the need to establish use rights in marine resources, the commons problem. © 2010 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.

Amiro B.,University of Manitoba
Agricultural and Forest Meteorology | Year: 2010

Annual net ecosystem production (NEP) was estimated at three boreal forest sites where open-path infrared gas analysers were used in eddy covariance systems. The analysers showed apparent ecosystem uptake of carbon dioxide during frozen conditions where small net respiration was expected. Previous studies have shown this to be largely caused by instrument heating creating an additional heat flux that is not used in density corrections. A set of meteorological conditions where good data could be extracted in cold temperatures was not evident. Annual NEP was evaluated based on estimates that used a heating correction of Burba et al. (2008) or removal of data when air temperature <0°C, with replacement using a regression function based on soil temperature. The methods agreed within ±0.5tCha-1y-1 which is similar to the potential bias that could be caused by density corrections if accounting for energy balance closure at some sites. Annual NEP (±0.5tCha-1y-1) for boreal forest sites that had experienced stand-replacing fire was: a 6-year-old site was losing 0.6, a 15-year-old site was gaining 0.9, and a 27-year-old site was losing 0.8, for 2-3-year averages. It is difficult to reduce the uncertainty in annual NEP estimates at these boreal sites because of the long cold periods. Cold-weather anomalies have been observed by other researchers, but this has not been a universal problem. © 2010 Elsevier B.V.

Abou-Setta A.M.,University of Manitoba
Cochrane database of systematic reviews (Online) | Year: 2013

Various options exist for treating endometriosis, including surgical, medical, such as ovarian suppression, or a combination of these strategies. Surgical treatment of endometriosis aims to remove visible areas of endometriosis. The aim of medical therapy is to inhibit growth of endometriotic implants by induction of a hypo-estrogenic state. Treatment with a hormone-releasing intrauterine device, using levonorgestrel (LNG-IUD), has also been suggested. To determine whether postoperative LNG-IUD insertion in women with endometriosis improves pain and reduces recurrence of symptoms compared with no postoperative treatment, postoperative insertion of a placebo, or postoperative therapy. The following databases were searched from inception to June 2012: Cochrane Menstrual Disorders and Subfertility Group Specialised Register of controlled trials, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PsycINFO, CINAHL, and the World Health Organization (WHO) International Clinical Trials Registry Platform. EMBASE was searched from 2010 to June 2012. The citation lists of relevant publications, review articles, abstracts of scientific meetings, and included studies were also searched. Trials were included if they compared women undergoing surgical treatment for endometriosis with uterine preservation and then randomised within three months to LNG-IUD insertion versus no postoperative treatment, placebo (inert IUD), or other treatment. Diagnostic laparoscopy alone was not considered suitable treatment. Two review authors independently selected studies for inclusion and extracted data to allow for an intention-to-treat analysis. For dichotomous data, the risk ratio (RR) and 95% confidence interval (CI) were calculated using the Mantel-Haenszel random-effects method. For continuous data, the mean difference (MD) and 95% CI were calculated using the inverse variance random-effects method. Three randomised controlled trials were included. In two trials, there was a statistically significant reduction in the recurrence of painful periods in the LNG-IUD group compared with expectant management (RR 0.22, 95% CI 0.08 to 0.60, 95 women, I(2) = 0%, moderate strength of evidence). The proportion of women who were satisfied with their treatment was also higher in the LNG-IUD group but did not reach statistical significance (RR 1.21, 95% CI 0.80 to 1.82, 95 women, I(2) = 0%). The number of women reporting a change in menstruation was significantly higher in the LNG-IUD group (RR 37.80, 95% CI 5.40 to 264.60, 95 women, I(2) = 0%) but the number of women not completing the allocated treatment did not differ between groups (RR 0.66, 95% CI 0.08 to 5.25, I(2) = 43%).In one trial, women receiving LNG-IUD noted lower pain scores compared with women receiving gonadotrophin-releasing hormone agonists (MD -0.16, 95% CI -2.02 to 1.70, 40 women) but this did not reach statistical significance. There is limited but consistent evidence showing that postoperative LNG-IUD use reduces the recurrence of painful periods in women with endometriosis. Further well-designed RCTs are needed to confirm these findings.

Schroth R.,University of Manitoba
Rural and remote health | Year: 2010

This study investigated the prevalence of early childhood caries (ECC) among Hutterite preschool children from different colonies in southwestern Manitoba, Canada. Following informed consent from the child's parent, children under 72 months of age underwent a dental screening examination. Approval was granted by the University of Manitoba's Health Research Ethics Board. A total of 66 children with a mean age of 40.1 ± 20.1 months participated. The prevalence of ECC was 53%, while the mean decayed, extracted and filled teeth (deft) score was 2.8 ± 4.0 (range 0-20). A total of 42.4% had severe ECC (S-ECC). There was no difference in prevalence among the 6 participating colonies. Only 15 children had already been to the dentist, with the majority of these visits due to decay or dental pain. Of those, the mean age for a first visit was 2.7 ± 0.6 years. Children with ECC were determined to be significantly older than those who were caries-free (p<.0001). Early childhood caries and higher caries rates were associated with lower maternal ratings of their child's dental health. Both ECC and increased deft scores were significantly associated with the number of children in the home. This is the first study to report the prevalence of primary tooth decay in Hutterite children. Rates were comparable with other Canadian data for rural dwelling children. Effective and culturally appropriate prevention and health promotion activities are warranted, including fluoride varnish and early dental visits.

Healy S.,University of Manitoba
Discovery medicine | Year: 2011

14-3-3s are phosphoserine- or phosphothreonine-binding proteins, which are involved in a variety of cellular processes, including gene regulation, differentiation, cell cycle progression, and metabolism. Their mechanism of regulation is typically to induce a conformational change on the target phosphoprotein, which can alter its catalytic activity, localization within the cell, or interactions with other proteins. In addition, 14-3-3s can act as a scaffolding protein, leading to multiprotein complex formation on the target phosphoprotein. As such, 14-3-3s are integrated into a number of important phosphorylation-dependent signaling pathways. In this review, we will examine the interaction of 14-3-3 with chromatin and chromatin modifying enzymes, specifically with phosphorylated histone H3 and histone deacetyltransferases, respectively. Through diverse mechanisms, these interactions directly affect the expression of target genes, many of which are known oncogenes and lead to tumorigenesis and metastasis. Various research studies have indicated that the mechanism of 14-3-3 interaction and its role in transcription is complex and diverse, and likely involving additional components as yet undefined.

Rush D.,University of Manitoba
Transplantation Reviews | Year: 2013

The discovery of the first calcineurin inhibitor (CNI), cyclosporine, represents a watershed event in the history of immunosuppression, as it was the first drug shown to reversibly inhibit T-lymphocyte function, therefore allowing for one of the major breakthroughs in modern medicine, that of organ transplantation.Calcineurin inhibitors remain the most effective and widely used immunosuppressive agents in organ transplantation today. The 2010 OPTN/SRTR Annual Report showed that 96% of renal transplant recipients were on CNI at the time of discharge from hospital.The prolonged use of CNI, however, may result in renal toxicity, renal dysfunction and eventual renal failure in both recipients of renal and other solid organ transplants, as well as in patients treated with these agents for autoimmune diseases.This brief review, while acknowledging that CNI toxicity does indeed exist, will focus on the successful use of CNI in renal transplant recipients, highlighting recent observations that provide alternative explanations for some of the adverse outcomes that have been attributed to CNI nephrotoxicity in the past. © 2013 Elsevier Inc.

Mutter T.C.,University of Manitoba
The Cochrane database of systematic reviews | Year: 2013

Hydroxyethyl starches (HES) are synthetic colloids commonly used for fluid resuscitation to replace intravascular volume, yet they have been increasingly associated with adverse effects on kidney function. This is an update of a Cochrane review first published in 2010. To examine the effects of HES on kidney function compared to other fluid resuscitation therapies in different patient populations. We searched the Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library), MEDLINE, EMBASE, MetaRegister and reference lists of articles. The most recent search was completed on November 19, 2012. Randomised controlled trials (RCTs) and quasi-RCTs in which HES was compared to an alternate fluid therapy for the prevention or treatment of effective intravascular volume depletion. Primary outcomes were renal replacement therapy (RRT), author-defined kidney failure and acute kidney injury (AKI) as defined by the RIFLE criteria. Screening, selection, data extraction and quality assessments for each retrieved article were carried out by two authors using standardised forms. All outcomes were analysed using relative risk (RR) and 95% confidence intervals (95% CI). Authors were contacted when published data were incomplete. Preplanned sensitivity and subgroup analyses were performed after data were analysed with a random-effects model. This review included 42 studies (11,399 patients) including 19 studies from the original review (2010), as well as 23 new studies. Fifteen studies were excluded from the original review (nine retracted from publication due to concerns about integrity of data and six lacking individual patient creatinine data for the calculation of RIFLE criteria). Overall, there was a significant increase in the need for RRT in the HES treated individuals compared to individuals treated with other fluid therapies (RR 1.31, 95% CI 1.16 to 1.49; 19 studies, 9857 patients) and the number with author-defined kidney failure (RR 1.59, 95% CI 1.26 to 2.00; 15 studies, 1361 patients). The RR of AKI based on RIFLE-F (failure) criteria also showed an increased risk of AKI in individuals treated with HES products (RR 1.14, 95% CI 1.01 to 1.30; 15 studies, 8402 participants). The risk of meeting urine output and creatinine based RIFLE-R (risk) criteria for AKI was in contrast in favour of HES therapies (RR 0.95, 95% CI 0.91 to 0.99; 20 studies, 8769 patients). However, when RIFLE-R urine output based outcomes were excluded as per study protocol, the direction of AKI risk again favoured the other fluid type, with a non-significant RR of AKI in HES treated patients (RR 1.05, 95% CI 0.97 to 1.14; 8445 patients). A more robust effect was seen for the RIFLE-I (injury) outcome, with a RR of AKI of 1.22 (95% CI 1.08 to 1.37; 8338 patients). No differences between subgroups for the RRT and RIFLE-F based outcomes were seen between sepsis versus non-sepsis patients, high molecular weight (MW) and degree of substitution (DS) versus low MW and DS (≥ 200 kDa and > 0.4 DS versus 130 kDa and 0.4 DS) HES solutions, or high versus low dose treatments (i.e. ≥ 2 L versus < 2 L). There were differences identified between sepsis versus non-sepsis subgroups for the RIFLE-R and RIFLE-I based outcomes only, which may reflect the differing renal response to fluid resuscitation in pre-renal versus sepsis-associated AKI. Overall, methodological quality of the studies was good. The current evidence suggests that all HES products increase the risk in AKI and RRT in all patient populations and a safe volume of any HES solution has yet to be determined. In most clinical situations it is likely that these risks outweigh any benefits, and alternate volume replacement therapies should be used in place of HES products.

Jackson A.C.,University of Manitoba
The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques | Year: 2011

Worldwide, human rabies is prevalent where there is endemic dog rabies, but the disease may present unexpectedly in critical care units when suggestive clinical features have passed. In North America transmission from bats is most common and there is often no history of a bat bite or even contact with bats. Laboratory diagnostic evaluation for rabies includes serology plus skin biopsy, cerebrospinal fluid, and saliva specimens for rabies virus antigen and/or RNA detection. Rare patients have survived rabies, and most received rabies vaccine prior to the onset of illness. Therapeutic coma (midazolam and phenobarbital), ketamine, and antiviral therapies (dubbed the "Milwaukee Protocol") were given to a rabies survivor, but this therapy was likely not directly responsible for the favorable outcome. There have been many subsequent failures of similar therapeutic approaches. There is no scientific rationale for the use of therapeutic coma in human rabies. New approaches to treating human rabies need to be developed.

Karimi-Abdolrezaee S.,University of Manitoba
Advances in experimental medicine and biology | Year: 2012

Spinal cord injury (SCI) has remained a challenging area for scientists and clinicians due to the adverse and complex nature of its pathobiology. To date, clinical therapies for debilitating SCI are largely ineffective. However, emerging research evidence suggests that repair of SCI can be promoted by stem cell-based therapies in regenerative medicine. Over the past decade, therapeutic potential of different types of stem cells for the treatment of SCI have been investigated in preclinical models. These studies have revealed multiple beneficial roles by which stem cells can improve the outcomes of SCI. This chapter will summarize the recent advances in the application of stem cells in regenerative medicine for the repair of SCI.

Greenfield H.J.,University of Manitoba
World Archaeology | Year: 2010

Andrew Sherratt's (1981) model of the Secondary Products Revolution explored the effects of changes in the scale and nature of domestic animal exploitation on Old World societies. He proposed that the earliest domestic stock animals in the Near East (sheep, goat and cattle) were initially domesticated during the Neolithic for their primary products (meat, hide and bone), but that their more intensive exploitation for secondary animal products (milk, wool and traction) appeared in the Near East much later (during the Chalcolithic) and subsequently spread to surrounding regions (Europe and Asia). While the zooarchaeological evidence largely supports the model, questions have been raised about its veracity since there is evidence for pre-Chalcolithic exploitation of secondary products (e.g. ceramic lipid analyses). This paper summarizes past efforts to test the model, presents the results of recent research on the subject (e.g. artefactual, zooarchaeological and lipid analysis) and suggests directions for future research. Some of the discrepancies that have arisen between the archaeological, ceramic lipid and zooarchaeological data will be discussed. © 2010 Taylor & Francis.

Vannier J.-B.,DNA Response | Pavicic-Kaltenbrunner V.,DNA Response | Petalcorin M.I.R.,DNA Response | Ding H.,University of Manitoba | Boulton S.J.,DNA Response
Cell | Year: 2012

T loops and telomeric G-quadruplex (G4) DNA structures pose a potential threat to genome stability and must be dismantled to permit efficient telomere replication. Here we implicate the helicase RTEL1 in the removal of telomeric DNA secondary structures, which is essential for preventing telomere fragility and loss. In the absence of RTEL1, T loops are inappropriately resolved by the SLX4 nuclease complex, resulting in loss of the telomere as a circle. Depleting SLX4 or blocking DNA replication abolished telomere circles (TCs) and rescued telomere loss in RTEL1-/- cells but failed to suppress telomere fragility. Conversely, stabilization of telomeric G4-DNA or loss of BLM dramatically enhanced telomere fragility in RTEL1-deficient cells but had no impact on TC formation or telomere loss. We propose that RTEL1 performs two distinct functions at telomeres: it disassembles T loops and also counteracts telomeric G4-DNA structures, which together ensure the dynamics and stability of the telomere. © 2012 Elsevier Inc.

Yang W.,University of Guelph | Zhou H.,University of Guelph | Cicek N.,University of Manitoba
Critical Reviews in Environmental Science and Technology | Year: 2014

This paper provides a review of the up-to-date research on the treatment of micropollutants by UV-based processes. More than 140 scientific publications in the past 10 years were reviewed and analyzed, with emphasis on the peer-reviewed papers in the last three years (2009-2011). Previous studies showed that UV-based advanced oxidation processes (AOPs) could be efficient for the removal of a number of micropollutants in drinking water and wastewater although direct UV photolysis at disinfection dosages was proven not effective in removing most micropollutants. Among those UV-based AOPs, UV-oxidation with hydrogen peroxide (H2O2) has attracted great attention and shown numerous advantages as an advanced technology for micropollutants control. The public concern about the impact of micropollutants on the safety of drinking water and the increasing needs of safe water reuse will likely facilitate the application of UV-based processes for micropollutants control in drinking water treatment and water reuse. © 2014 Taylor & Francis Group, LLC.

Salman M.S.,University of Manitoba | Ikeda K.M.,University of Western Ontario
Canadian Journal of Neurological Sciences | Year: 2013

Introduction: Infantile-onset saccade initiation delay (ISID), also known as congenital ocular motor apraxia, is characterized by the inability to initiate volitional horizontal saccades. Other abnormalities including developmental delay and ataxia have been reported. The frequency of these abnormalities is unknown. We performed a detailed review of the medical literature to quantify features of ISID. Methods: We searched the English medical literature for articles related to ISID from 1952 to 2010. Whenever possible, patients were excluded if they had acquired SID, Joubert syndrome or neurodegenerative conditions. The minimum prevalence was calculated for each abnormality. Results: Sixty-six articles with information on 288 patients were included in the analysis. Head thrusts were reported in 84.7%. Blinks without head thrusts were used to initiate saccades in 41%. The fast phases of the optokinetic response and vestibulo-ocular reflex were impaired in 69.8% and 34.4% respectively. Smooth ocular pursuit was abnormal in 33%. Global developmental delay occurred in 41.3%, speech or language delay in 36.5%, cognitive delay in 17%, hypotonia in 35.8%, motor delay in 48.6%, and ataxia/clumsiness in 49.3% of patients. Neuroimaging was performed on 197 patients and was normal in 39.1%. Abnormalities involved the cerebellum (24.9%), cerebrum (15.7%), other infratentorial structures (11.7%), and corpus callosum (6.1%). Conclusions: Infantile-onset saccade initiation delay is frequently associated with deficits in reflexive saccades and less frequently with impaired smooth ocular pursuit. Developmental delay, hypotonia, and ataxia occur frequently in ISID, suggesting more global brain impairment and not just a saccadic disorder.

Warrington R.,University of Manitoba
Human Vaccines and Immunotherapeutics | Year: 2012

Allergic drug reactions occur when a drug, usually a low molecular weight molecule, has the ability to stimulate an immune response. This can be done in one of two ways. The first is by binding covalently to a self-protein, to produce a haptenated molecule that can be processed and presented to the adaptive immune system to induce an immune response. Sometimes the drug itself cannot do this but a reactive breakdown product of the drug is able to bind covalently to the requisite self-protein or peptide. The second way in which drugs can stimulate an immune response is by binding non-covalently to antigen presenting or antigen recognition molecules such as the major histocompatibility complex (MHC)or the T cell receptor. This is known as the p-I or pharmacological interaction hypothesis. The drug binding in this situation is reversible and stimulation of the response may occur on first exposure, not requiring previous sensitization. There is probably a dependence on the presence of certain MHC alleles and T cell receptor structures for this type of reaction to occur. © 2012 Landes Bioscience.

Nicolle L.E.,University of Manitoba
Infectious Disease Clinics of North America | Year: 2012

Catheter-acquired urinary infection is the most common device-associated healthcare-acquired infection. Although most patients are asymptomatic, symptomatic infection may occur and is associated with increased morbidity and costs. Long-term indwelling catheters are associated with more complex microbiology and greater morbidity than short-term catheters. The most effective way to prevent these infections is to restrict indwelling urinary catheter use to limited indications, and to discontinue use of a catheter as soon as feasible. Alternate means of managing bladder emptying, including external condom catheters for men and intermittent catheterization for patients with neurologic impairment of bladder emptying, should be used when possible. © 2012 Elsevier Inc.

Rafajlowicz E.,Wroclaw University of Technology | Pawlak M.,University of Manitoba | Steland A.,RWTH Aachen
IEEE Transactions on Information Theory | Year: 2010

This paper examines a new method for sequential detection of a sudden and unobservable change in a sequence of independent observations with completely unspecified distribution functions. A nonparametric detection rule is proposed which relies on the concept of a moving vertically trimmed box. As such, it will be coined as the Vertical Box Control Chart (V-Box Chart). Its implementation requires merely to count the number of data points which fall into the box attached to the last available observation. No a priori knowledge of data distributions is required and proper tuning of the box size provides a quick detection technique. This is supported by establishing statistical properties of the method which explain the role of the tuning parameters used in the V-Box Chart. These theoretical results are verified by simulation studies which indicate that the V-Box Chart may provide quick detection with zero delay for jumps of moderate sizes. Its averaged run length to detection is more favorable than the one for the classical EWMA method. By comparison with the classical Shewhart chart, which was optimized for normal errors, our method provides comparable or better performance. © 2006 IEEE.

Ritchie L.J.,University of Manitoba | Tuokko H.,University of Victoria
American Journal of Alzheimer's Disease and other Dementias | Year: 2010

Our objective was to compare the predictive ability of different models of mild cognitive impairment (MCI) as a marker of incipient dementia in a longitudinal population-based Canadian sample. We examined the use of existing, well-documented MCI criteria using data from persons who underwent a clinical examination in the second wave of the Canadian Study of Health and Aging (CSHA). Demographic characteristics, average neuropsychological test performance, and sample frequencies and conversion rates were calculated for each classification. Receiver operating characteristic (ROC) analyses were employed to assess the predictive power of each cognitive classification. The highest sample frequencies and conversion rates were associated with case definitions of multiple-domain MCI. The only diagnostic criteria to significantly predict dementia 5 years later was the cognitive impairment no dementia (CIND)-2 case definition. More restrictive MCI case definitions fail to address the varying temporal increases in decline across different cognitive domains in the progression from normal cognitive functioning and dementia. © The Author(s) 2010.

Simons F.E.R.,University of Manitoba
Current Opinion in Allergy and Clinical Immunology | Year: 2010

Purpose of Review: To evaluate the evidence base for the pharmacologic treatment of anaphylaxis. Recent findings: In this review, we focus on four classes of medications (the alpha/beta-agonist epinephrine (adrenaline), H1-antihistamines, H2-antihistamines, and glucocorticoids) that are used in healthcare settings for the initial treatment of anaphylaxis. Epinephrine and many H1-antihistamines and glucocorticoids were introduced before the era of randomized controlled trials and before the era of evidence-based medicine. In anaphylaxis, no randomized controlled trials that are free from methodological problems and meet current standards have been performed with these medications, or with H2-antihistamines. The evidence base for epinephrine injection is stronger than the evidence base for use of other medications in anaphylaxis. Guidelines unanimously recommend prompt injection of epinephrine as the life-saving first-line medication in anaphylaxis; however, they differ in their recommendations for H1-antihistamines, H2-antihistamines, and glucocorticoids. Epinephrine is the only medication that is universally available for anaphylaxis treatment in healthcare settings worldwide. Paradoxically, it is underused in anaphylaxis treatment. Summary: For ethical reasons, there should never be a placebo-controlled trial of epinephrine in anaphylaxis. We discuss why the possibility of conducting randomized placebo-controlled trials with H1-antihistamines, H2-antihistamines, and particularly with glucocorticoids in anaphylaxis should be considered in order to improve the evidence base for treatment and guide clinical decision-making. We also describe the precautions that will be needed if randomized controlled trials are conducted in anaphylaxis. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

The success of modern anticancer treatment is a composite function of enhanced efficacy of surgical, radiation and systemic treatment strategies and of our collective clinical abilities in supporting patients through the perils of their cancer journeys. Despite the widespread availability of antibacterial therapies, the threat of community- or healthcare facility-acquired bacterial infection remains a constant risk to patients during this journey. The rising prevalence of colonization by multidrug-resistant (MDR) bacteria in the population, acquired through exposure from endemic environments, antimicrobial stewardship and infection prevention and control strategies notwithstanding, increases the likelihood that such organisms may be the cause of cancer treatment-related infection and the likelihood of antibacterial treatment failure. The high mortality associated with invasive MDR bacterial infection increases the likelihood that many patients may not survive long enough to reap the benefits of enhanced anticancer treatments, thus threatening the societal investment in the cancer journey. Since cancer care providers arguably no longer have, and are unlikely to have in the foreseeable future, the antibacterial tools to reliably rescue patients from harm's way, the difficult ethical debate over the risks and benefits of anticancer treatments must now be reopened. © The Author 2012. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

Embree J.,University of Manitoba
Biochemistry and Cell Biology | Year: 2010

The pattern of illness associated with the first wave of the pandemic influenza A H1N1 (swine flu) in the spring and early summer of 2009 in regions of the province of Manitoba in Canada was more severe, on a population basis, than any other northern hemisphere jurisdiction outside of Mexico City. Manitoba accounted for 50% of intensive care admissions and 25% of pediatric admissions, but only 6.5% of deaths, attributable to the virus in Canada during the first wave. Activation and use of emergency response protocols embedded within the routine health authority management system and good communication between the diagnostic laboratory, public health, and health care practitioners was effective in coping with the sudden need for hospitalization of large numbers of children and young adults with severe respiratory illness over a short time period. Early treatment with oseltamivir was associated with a shorter duration of hospitalization among children. Intensive education of health care providers, patients, and visitors, along with close monitoring of infection prevention and control practices, were instrumental in preventing both nosocomial and health care worker infections.

Singh H.,University of Manitoba
Journal of clinical oncology : official journal of the American Society of Clinical Oncology | Year: 2013

Site-specific risk of colorectal cancer (CRC) among survivors of endometrial cancer (EC) is not known. The objective of the present study was to assess the risk of CRC (overall and subsite specific) among EC survivors. A historical cohort study was performed by linking the Manitoba Cancer Registry and the Manitoba Health administrative databases. Each subject diagnosed with EC as her first cancer between 1987 and 2008 was age matched with up to five women with no history of invasive cancer on the index date (date of EC diagnosis). All subjects were followed up to the date of diagnosis of CRC or another cancer, death, migration, or study end point (December 31, 2009). Competing-risk proportional hazards models were used to compare the CRC incidence rates with adjustment for age, history of lower gastrointestinal endoscopy, and socioeconomic status. There were three mutually exclusive (and competing) outcomes: CRC, another primary cancer, and death. A total of 3,115 women with EC and 15,084 without EC were followed up for a total of 145,502 person-years. Women diagnosed with EC at age ≤ 50 years had an increased risk of being diagnosed with CRC (all CRC: hazard ratio [HR] = 4.41; 95% CI, 1.47 to 13.26; right-sided CRC: HR = 7.48; 95% CI, 1.29 to 43.28). There was no increased risk of all CRC among women 51 to 65 years of age or those older than 65 years at the time of EC diagnosis. However, women 51 to 65 years of age at EC diagnosis had an increased risk of right-sided CRC (HR = 2.30; 95% CI, 1.05 to 5.01). This study suggests young women (age ≤ 50 years) with EC are at increased risk of CRC; risk of right-sided CRC is also increased in women 51 to 65 years old at EC diagnosis.

Marinangeli C.P.F.,Kellogg Canada Inc. | Jones P.J.H.,University of Manitoba
Nutrition Research Reviews | Year: 2013

Over the last decade the concept of functional foods and nutraceuticals (FFN) has gained support from various stakeholders including the food industry, scientific and academic community, government institutions or regulators, producers and consumers. However, as one begins to evaluate the global FFN industry, several issues emerge including (i) a lack of consensus across jurisdictions for acknowledging safe and efficacious FFN, (ii) challenges regarding the classification of novel food-derived bioactives as FFN or drugs, and (iii) a disconnect between nutrient requirements and dosages of FFN required to facilitate health benefits. The objectives of the present review are to discuss the role of existing stakeholders within the FFN marketplace and identify performance indicators for growth within the FFN sector. In addition, the following report provides feasible resolutions to present and future challenges facing the global FFN industry to ensure sustained long-term growth. © The Authors 2013.

Dillon R.L.,University of Manitoba | Muller W.J.,McGill University
Cancer Research | Year: 2010

The phosphatidylinositol 3′ kinase/Akt pathway is frequently dysregulated in cancer, which can have unfavorable consequences in terms of cell proliferation, survival, metabolism, and migration. Increasing evidence suggests that Akt1, Akt2, and Akt3 play unique roles in breast cancer initiation and progression. We have recently shown that in contrast to Akt1, which accelerates mammary tumor induction in transgenic mice, Akt2 promotes metastasis of tumor cells without affecting the latency of tumor development. Despite the distinct phenotypic outputs resulting from Akt1 or Akt2 activation, very little is known about the mode by which such unique functions originate from these highly related kinases. Here we discuss potential mechanisms contributing to the differing functional specificity of Akt1 and Akt2 with respect to migration, invasion, and metastasis. ©2010 AACR.

Mai S.,University of Manitoba
Journal of Cellular Biochemistry | Year: 2010

Telomeres are the ends of chromosomes and protect them from degradation and fusion. As such, their stability is required for normal cellular function. Telomere dysfunction is found often at the origin of cellular transformation and contributes to the onset of genomic instability, a hallmark of cancer cells. In this article, I discuss current data and concepts on telomere-mediated chromosomal rearrangements in cancer. © 2010 Wiley-Liss, Inc.

Renault S.,University of Manitoba
Acta Physiologiae Plantarum | Year: 2012

Red-osier dogwood (Cornus sericea L.) seedlings from three seed sources of different climatic conditions were treated hydroponically with 0-100 mM NaCl to compare their salinity tolerance. The control seedlings from the coldest location, Alberta (AB) had the lowest biomass and transpiration rate, as well as the highest photosynthetic water use efficiency. When exposed to 100 mM NaCl for 1 week, the seedlings from AB maintained a higher photosynthetic rate and stomatal conductance than the seedlings from the low precipitation location, British Columbia (BC), and the high precipitation location, New Brunswick (NB). After 2 weeks of treatment at this highest salt concentration, leaf injury occurred in the plants from all the locations suggesting that in spite of early differences, the seedlings from all locations may not be able to survive the salinity stress over time. In contrast, when plants were exposed to 50 mM NaCl, the seedlings from AB had low level of leaf injury, followed by the plants from BC compared with the NB seedlings. Furthermore, at this moderate salt concentration, the seedlings from NB (with the highest biomass for the control) had the lowest root relative growth rate and the highest leaf area; while the seedlings from AB and BC had the highest photosynthetic water use efficiency. The seedlings from AB were able to retain more K in the roots than the seedlings from NB, suggesting a higher level of salinity tolerance. Lower chloride content was observed in the leaves of the AB seedlings than in the BC seedlings. The results of this study show that when exposed to 50 mM NaCl, the seedlings from the cold (AB) and dry (BC) locations had higher salt tolerance than the seedlings from the milder climate (NB). These results suggest that cross tolerance may occur in red-osier dogwood; however, it varies depending on the level of salinity stress. © 2012 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.

Barclay-Goddard R.E.,University of Manitoba
Cochrane database of systematic reviews (Online) | Year: 2011

Activity limitations of the upper extremity are a common finding for individuals living with stroke. Mental practice (MP) is a training method that uses cognitive rehearsal of activities to improve performance of those activities. To determine if MP improves the outcome of upper extremity rehabilitation for individuals living with the effects of stroke. We searched the Cochrane Stroke Group Trials Register (November 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, November 2009), PubMed (1965 to November 2009), EMBASE (1980 to November 2009), CINAHL (1982 to November 2009), PsycINFO (1872 to November 2009), Scopus (1996 to November 2009), Web of Science (1955 to November 2009), the Physiotherapy Evidence Database (PEDro), CIRRIE, REHABDATA, ongoing trials registers, and also handsearched relevant journals and searched reference lists. Randomised controlled trials involving adults with stroke who had deficits in upper extremity function. Two review authors independently selected trials for inclusion. We considered the primary outcome to be the ability of the arm to be used for appropriate tasks (i.e. arm function). We included six studies involving 119 participants. We combined studies that evaluated MP in addition to another treatment versus the other treatment alone. Mental practice in combination with other treatment appears more effective in improving upper extremity function than the other treatment alone (Z = 3.48, P = 0.0005; standardised mean difference (SMD) 1.37; 95% confidence interval (CI) 0.60 to 2.15). We attempted subgroup analyses, based on time since stroke and dosage of MP; however, numbers in each group were small. We evaluated the quality of the evidence with the PEDro scale, ranging from 6 to 9 out of 10; we determined the GRADE score to be moderate. There is limited evidence to suggest that MP in combination with other rehabilitation treatment appears to be beneficial in improving upper extremity function after stroke, as compared with other rehabilitation treatment without MP. Evidence regarding improvement in motor recovery and quality of movement is less clear. There is no clear pattern regarding the ideal dosage of MP required to improve outcomes. Further studies are required to evaluate the effect of MP on time post stroke, volume of MP that is required to affect the outcomes and whether improvement is maintained long-term. Numerous large ongoing studies will soon improve the evidence base.

Leslie W.D.,University of Manitoba
Journal of Clinical Endocrinology and Metabolism | Year: 2012

Context: Differences in bone mineral density (BMD) as assessed with dual-energy x-ray absorptiometry are observed between geographic and ethnic groups, with important implications in clinical practice. Evidence Acquisition: PubMed was employed to identify relevant studies. A review of the literature was conducted, and data were summarized and integrated. Evidence Synthesis: The available data highlight the complex ethnic variations in BMD, which only partially account for observed variations in fracture rates. Factors contributing to ethnic differences include genetics, skeletal size, body size and composition, lifestyle, and social determinants. Despite BMD differences, the gradient of risk for fracture from BMD and other clinical risk factors appears to be similar across ethnic groups. Furthermore, BMD variation is greater within an ethnic population than between ethnic populations. New imaging technologies have identified ethnic differences in bone geometry, volumetric density, microarchitecture, and estimated bone strength that may contribute to a better understanding of ethnic differences in fracture risk. Conclusions: Factors associated with ethnicity affect BMD and fracture risk through direct and indirect mechanisms. Copyright © 2012 by The Endocrine Society.

Anderson W.G.,University of Manitoba
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology | Year: 2012

The endocrine underpinnings of the stress response in fish have been the subject of intense research for well over 50. years. Much of the research has focussed on teleost fish and so the endocrine mechanisms for cortisol production, transport and action at the target site have received significant attention. However, corticosteroidogenesis in elasmobranchs is exceptional on a number of levels. Unlike teleost fish the interrenal tissue is anatomically distinct from both renal and chromaffin (catecholamine producing) tissue; further the final product, 1α-hydroxycorticosterone (1α-OH-B), is unique to chondrichthyans where the carbon atom at position 1 of corticosterone has a hydroxyl group attached in the α orientation. The homologous nature of interrenal tissue in elasmobranchs presents an obvious advantage in the study of corticosteroidogenesis, however, the unique chemical nature of 1α-OH-B has presented distinct disadvantages as it has proven to be difficult to synthesise, and therefore studies examining the mineralocorticoid and glucocorticoid actions of this steroid are limited. Over the last decade molecular techniques have provided significant insight in the involvement of corticosteroiogenic enzymes in the elasmobranch interrenal in addition to the evolution of corticosteroid receptors. Given the number of excellent reviews focussing on the role of cortisol in the stress response of teleost fish, this short review aims to synthesise the endocrine basis for the synthesis, release, and action, of the enigmatic 1α-OH-B in elasmobranch fish. © 2011 Elsevier Inc.

Chernomas W.M.,University of Manitoba
Nursing leadership (Toronto, Ont.) | Year: 2010

The workplace for new graduates must be a constructive learning environment to facilitate their development. Nurse managers need new graduates who can "hit the ground running." Conflict between the needs of new nurses and the realities of the workplace often creates role confusion and tension in new graduates and threatens employers' ability to retain them. As part of a larger study that examined the effectiveness of a new strategy on new nurse retention and workplace integration, we conducted focus groups with new nurses and nurse managers. This paper discusses the perspectives of new nurses on their role transition from graduates to practising professionals and the perspectives of nurse managers on the workplace integration of new nurses. The thematic findings integrate new nurses' perspectives on their needs during role transition with the perspectives of nurse managers in meeting those needs. The discussion includes strategies to facilitate successful transition and integration of new nurses into the workplace within the context of recruitment and retention.

Alfa M.J.,University of Manitoba
American Journal of Infection Control | Year: 2013

The overall risk of infection from medical devices is very low, but high infection transmission rates have been related to inadequate reprocessing of arthroscopic shavers and flexible duodenoscopes. Monitoring of manual and automated cleaning is needed to ensure that inadequately cleaned medical devices are recleaned prior to disinfection or sterilization. Copyright © 2013 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Fernyhough P.,University of Manitoba | Fernyhough P.,St Boniface Hospital Research Center | Calcutt N.A.,University of California at San Diego
Cell Calcium | Year: 2010

Abnormal neuronal calcium (Ca2+) homeostasis has been implicated in numerous diseases of the nervous system. The pathogenesis of two increasingly common disorders of the peripheral nervous system, namely neuropathic pain and diabetic polyneuropathy, has been associated with aberrant Ca2+ channel expression and function. Here we review the current state of knowledge regarding the role of Ca2+ dyshomeostasis and associated mitochondrial dysfunction in painful and diabetic neuropathies. The central impact of both alterations of Ca2+ signalling at the plasma membrane and also intracellular Ca2+ handling on sensory neurone function is discussed and related to abnormal endoplasmic reticulum performance. We also present new data highlighting sub-optimal axonal Ca2+ signalling in diabetic neuropathy and discuss the putative role for this abnormality in the induction of axonal degeneration in peripheral neuropathies. The accumulating evidence implicating Ca2+ dysregulation in both painful and degenerative neuropathies, along with recent advances in understanding of regional variations in Ca2+ channel and pump structures, makes modulation of neuronal Ca2+ handling an increasingly viable approach for therapeutic interventions against the painful and degenerative aspects of many peripheral neuropathies. © 2009 Elsevier Ltd. All rights reserved.

Shen G.X.,University of Manitoba
Canadian Journal of Physiology and Pharmacology | Year: 2010

Cardiovascular diseases are the predominant cause of death in patients with diabetes mellitus. Underlying mechanism for the susceptibility of diabetic patients to cardiovascular diseases remains unclear. Elevated oxidative stress was detected in diabetic patients and in animal models of diabetes. Hyperglycemia, oxidatively modified atherogenic lipoproteins, and advanced glycation end products are linked to oxidative stress in diabetes. Mitochondria are one of major sources of reactive oxygen species (ROS) in cells. Mitochondrial dysfunction increases electron leak and the generation of ROS from the mitochondrial respiratory chain (MRC). High levels of glucose and lipids impair the activities of MRC complex enzymes. NADPH oxidase (NOX) generates superoxide from NADPH in cells. Increased NOX activity was detected in diabetic patients. Hyperglycemia and hyperlipidemia increased the expression of NOX in vascular endothelial cells. Accumulated lines of evidence indicate that oxidative stress induced by excessive ROS production is linked to many processes associated with diabetic cardiovascular complications. Overproduction of ROS resulting from mitochondrial dysfunction or NOX activation is associated with uncoupling of endothelial nitric oxide synthase, which leads to reduced production of nitric oxide and endothelial-dependent vasodilation. Gene silence or inhibitor of NOX reduced oxidized or glycated LDL-induced expression of plasminogen activator inhibitor-1 in endothelial cells. Statins, hypoglycemic agents, and exercise may reduce oxidative stress in diabetic patients through the reduction of NOX activity or the improvement of mitochondrial function, which may prevent or postpone the development of cardiovascular complications.

Hess J.E.,Columbia River Inter Tribal Fish Commission | Campbell N.R.,Columbia River Inter Tribal Fish Commission | Close D.A.,University of British Columbia | Docker M.F.,University of Manitoba | Narum S.R.,Columbia River Inter Tribal Fish Commission
Molecular Ecology | Year: 2013

Unlike most anadromous fishes that have evolved strict homing behaviour, Pacific lamprey (Entosphenus tridentatus) seem to lack philopatry as evidenced by minimal population structure across the species range. Yet unexplained findings of within-region population genetic heterogeneity coupled with the morphological and behavioural diversity described for the species suggest that adaptive genetic variation underlying fitness traits may be responsible. We employed restriction site-associated DNA sequencing to genotype 4439 quality filtered single nucleotide polymorphism (SNP) loci for 518 individuals collected across a broad geographical area including British Columbia, Washington, Oregon and California. A subset of putatively neutral markers (N = 4068) identified a significant amount of variation among three broad populations: northern British Columbia, Columbia River/southern coast and 'dwarf' adults (FCT = 0.02, P ≪ 0.001). Additionally, 162 SNPs were identified as adaptive through outlier tests, and inclusion of these markers revealed a signal of adaptive variation related to geography and life history. The majority of the 162 adaptive SNPs were not independent and formed four groups of linked loci. Analyses with matsam software found that 42 of these outlier SNPs were significantly associated with geography, run timing and dwarf life history, and 27 of these 42 SNPs aligned with known genes or highly conserved genomic regions using the genome browser available for sea lamprey. This study provides both neutral and adaptive context for observed genetic divergence among collections and thus reconciles previous findings of population genetic heterogeneity within a species that displays extensive gene flow. © 2012 John Wiley & Sons Ltd.

Lynch J.P.,University of California at Los Angeles | Clark N.M.,Loyola University | Zhanel G.G.,University of Manitoba
Expert Opinion on Pharmacotherapy | Year: 2013

Introduction: Bacteria within the family Enterobacteriaceae are important pathogens in nosocomial and community settings. Over the past two decades, antimicrobial resistance among Enterobacteriaceae dramatically escalated worldwide. The authors review the mechanisms of antimicrobial resistance among Enterobacteriaceae, epidemiology and global spread of resistance elements and discuss therapeutic options. Areas covered: An exhaustive search for literature relating to Enterobacteriaceae was performed using PubMed, using the following key words: Enterobacteriaceae; Klebsiella pneumoniae; Escherichia coli; antimicrobial resistance; plasmids; global epidemiology; carbapenemases (CPEs); extended spectrum β-lactamases (ESBLs) and multidrug resistance (MDR). Expert opinion: Enterobacteriaceae are inhabitants of intestinal flora and spread easily among humans (via hand carriage, contaminated food or water or environmental sources). Antimicrobial resistance may develop via plasmids, transposons or other mobile resistance elements. Mutations conferring resistance typically increase over time; the rate of increase is amplified by selection pressure from antibiotic use. Factors that enhance spread of antimicrobial resistance include: crowding; lack of hygiene; overuse and over-the-counter use of antibiotics; tourism; refugees and international travel. Clonal spread of resistant organisms among hospitals, geographic regions and continents has globally fueled the explosive rise in resistance. The emergence and widespread dissemination of MDR clones containing novel resistance elements (particularly ESBLs and CPEs) has greatly limited therapeutic options. In some cases, infections due to MDR Enterobacteriaceae are untreatable with existing antimicrobial agents. The authors discuss current and future therapeutic options for difficult-to-treat infections due to these organisms. © 2013 Informa UK, Ltd.

Wall D.A.,University of Manitoba
Best Practice and Research: Clinical Haematology | Year: 2010

When selecting a cord blood unit for transplantation a transplant program must, in addition to considering HLA match and cell dose, know that the unit is potent, pure and will not transfer an infectious, hematologic or immunologic disease. While these same issues also apply to adult unrelated donors the fact that cord blood has been processed and stored, often years earlier, at a cell processing facility other than the one affiliated with the transplant program has resulted in a transfer of responsibilities from the transplant program to the cord bank. The transplant programs rely on the cord blood banks for all aspects of collection, screening, testing, processing and storage. Additionally the intermediary registries that are responsible for coordinating communications between the banks and transplant programs are important partners in a comprehensive approach to cord blood quality management. Since cord blood units frequently cross international borders it is critical that international regulatory standards be established and implemented to cover all steps in the production and sharing of cord blood for transplantation. Activities of NetCord/FACT, AABB, CIBMTR, World Marrow Donor Association and others are coming together under the Alliance for Harmonization of Cellular Therapy Accreditation to harmonize practice worldwide. © 2010 Elsevier Ltd. All rights reserved.

Fry M.,University of Manitoba | Ferguson A.V.,Queens University
International Journal of Peptides | Year: 2010

Ghrelin, a peptide hormone secreted by the stomach, has been shown to regulate energy homeostasis by modulating electrical activity of neurons in the central nervous system (CNS). Like many circulating satiety signals, ghrelin is a peptide hormone and is unable to cross the blood-brain barrier without a transport mechanism. In this review, we address the notion that the arcuate nucleus of the hypothalamus is the only site in the CNS that detects circulating ghrelin to trigger orexigenic responses. We consider the roles of a specialized group of CNS structures called the sensory circumventricular organs (CVOs), which are not protected by the blood-brain barrier. These areas include the subfornical organ and the area postrema and are already well known to be key areas for detection of other circulating hormones such as angiotensin II, cholecystokinin, and amylin. A growing body of evidence indicates a key role for the sensory CVOs in the regulation of energy homeostasis. © 2010 M. Fry and A. V. Ferguson.

Kayastha N.,Nanyang Technological University | Niyato D.,Nanyang Technological University | Wang P.,Nanyang Technological University | Hossain E.,University of Manitoba
Proceedings of the IEEE | Year: 2011

The mobile social network (MSN) combines techniques in social science and wireless communications for mobile networking. The MSN can be considered as a system which provides a variety of data delivery services involving the social relationship among mobile users. This paper presents a comprehensive survey on the MSN specifically from the perspectives of applications, network architectures, and protocol design issues. First, major applications of the MSN are reviewed. Next, different architectures of the MSN are presented. Each of these different architectures supports different data delivery scenarios. The unique characteristics of social relationship in MSN give rise to different protocol design issues. These research issues (e.g., community detection, mobility, content distribution, content sharing protocols, and privacy) and the related approaches to address data delivery in the MSN are described. At the end, several important research directions are outlined. © 2011 IEEE.

Berkes F.,University of Manitoba | Ross H.,University of Queensland
Society and Natural Resources | Year: 2013

We explore opportunities for an integrated approach in community resilience to inform new research directions and practice, using the productive common ground between two strands of literature on community resilience, one from social-ecological systems and the other from the psychology of development and mental health. The first strand treats resilience as a systems concept, dealing with adaptive relationships and learning in social-ecological systems across nested levels, with attention to feedbacks, nonlinearity, unpredictability, scale, renewal cycles, drivers, system memory, disturbance events, and windows of opportunity. The second strand emphasizes identifying and developing community strengths, and building resilience through agency and self-organization, with attention to people-place connections, values and beliefs, knowledge and learning, social networks, collaborative governance, economic diversification, infrastructure, leadership, and outlook. An integrative approach seated in the complex adaptive system and ecological understanding can incorporate the identification of explicit social strengths and connections to place, activated by agency and self-organizing. © 2013 Copyright Taylor and Francis Group, LLC.

Torabi M.,University of Manitoba
Environmetrics | Year: 2013

In this paper, generalized additive mixed models are constructed for the analysis of geographical and temporal variability of disease ratios. In this class of models, spatio-temporal models that use conditionally autoregressive smoothing across the spatial dimension and B-spline smoothing over the temporal dimension are considered. The frequentist analysis of these complex models is computationally difficult. On the other hand, the advent of the Markov chain Monte Carlo algorithm has made the Bayesian analysis of complex models computationally convenient. Recently developed data cloning (DC) method provides a frequentist approach to mixed models and equally computationally convenient. We propose to use DC, which yields to maximum likelihood estimation, to conduct frequentist analysis of spatio-temporal modeling of disease ratios. The advantages of DC approach are that the non-estimable parameters are flagged automatically and prediction (and prediction intervals) of the smoothing incidence ratios over space and time are easily obtained. We illustrate this approach using a real dataset of yearly childhood asthma visits to hospital in the province of Manitoba, Canada, during 2000-2010. The performance of the DC approach is also studied through a simulation study. © 2013 John Wiley & Sons, Ltd.

Daayf F.,University of Manitoba
Canadian Journal of Plant Pathology | Year: 2015

Verticillium wilt is caused mainly by Verticillium dahliae Kleb. and is a constraint for growers of many economic crops and ornamental plant species. Disease control necessitates the use of multiple methods usually coordinated as part of a disease management strategy. Unlike foliar diseases, much information is lacking for knowledge-based strategies to be developed for managing root infection. Revealing the mechanisms of interaction between the pathogen and its hosts would be a first step towards achieving such a goal. More effort needs to be directed towards understanding how the pathogen infects and colonizes its hosts, and how plants respond to these invaders. This review describes several of the efforts to elucidate the interactions of V. dahliae with its hosts, and raises some of the key points that need to be addressed in future work on this important disease. © 2014 The Canadian Phytopathological Society.

Modeling various neuronal functions in search of emergent properties may achieve success when the gold standard of replicating the models in physical systems starts exhibiting some of these properties. Since very large number of functions can be modeled and need testing, we suggest an alternate method of examining higher brain functions: seeing them as internal sensations formed from their hypothetical basic units. Here, we explain the need to replicate the natural mechanism using electronic circuits, discuss some of the technical aspects and introduce some concepts for searching for properties of internal sensations evolving from them. © 2012 Vadakkan; licensee BioMed Central Ltd.

Smith J.R.,Hoffmann-La Roche | Ariano R.E.,University of Manitoba | Toovey S.,University College London
Critical Care Medicine | Year: 2010

The clinical course of pandemic H1N1 2009 influenza can be severe, particularly in the very young and patients with comorbidities. Pandemic H1N1 2009 is sensitive to the antiviral agents oseltamivir and zanamivir but is resistant to the M2 inhibitors. Although few clinical data are yet available, treatment of pandemic H1N1 2009 influenza in hospital settings with oseltamivir or zanamivir appears to be beneficial. In hospitalized patients with severe influenza treated with oseltamivir, mortality and length of stay are significantly reduced, and viral load is reduced more quickly than in untreated patients. In patients at high risk treated with oseltamivir or zanamivir, reductions in the risk of complica-tions and mortality after treatment have been demonstrated with oseltamivir and zanamivir, although there are fewer data on the latter. There is no evidence yet that other antiviral agents are effective in severe or pandemic H1N1 2009 influenza. Current World Health Organization guidance strongly recommends the use of oseltamivir for severe or progressive infection with pandemic H1N1 2009, with zanamivir as an alternative if the infecting virus is oseltamivir-resistant. Very little resistance to oseltamivir has been found to date. Copyrignt © 2010 by the Society ot Critical Care Medicine and Lippincott Williams & Wilkins.

Campbell J.M.,University of Manitoba
Forest Policy and Economics | Year: 2012

Over the past decades there has been an increase in negative interactions between humans and bears. In response to these concerns a number of initiatives such as Bear Smart, Bear Aware and Bear Wise have evolved to help communities learn to deal with bears. All these programs share the goals of educating people about how to avoid attracting bears to their property or campsite, changing behaviors that serve to attract bears and what to do should a bear approach. This study examines the efficacy of the Bear Smart program in two cottage communities along the shores of Lake Winnipeg. Audits of bear attractants were conducted on cottage properties prior to and after the implementation of the Bear Smart awareness program. In addition, a population survey based on the Theory of Planned Behavior was conducted in order to identify attitudes and intentions with respect to bear smart behavior. Results indicate that despite the educational programming conducted throughout the cottaging season and positive attitudes toward bear smart behavior, little had actually been done by cottagers to reduce their cottage properties' attractiveness to bears. The results of the property bear attractant audits showed minimal effect in terms of reduced attractants on cottage properties in either of the two communities. While on the surface this might suggest that the targeted multi channel educational programs were not effective in changing behavior, it is possible that the effect was masked by the normal seasonal increase in attractants as the cottage season progressed. In particular behaviors relating to the proper handling of food and garbage elicited very positive attitude scores. When considered in light of the evaluation of removing bird feeders (with and without food) where 16% and 24% respectively state removing feeders is quite to very unacceptable, the issue of communicating the role of bird feeders as an attraction is perhaps the most important message to convey successfully. The Theory of Planned Behavior allowed examination into the constituent components of these attitudes that were not positively evaluated by all cottagers and provides insight to direct future communication and awareness programs. © 2012 Elsevier B.V..

Ateah C.A.,University of Manitoba
Journal of Pediatric Health Care | Year: 2013

Introduction: The purpose of this pilot project was to determine first-time expectant parents' perceptions of a parent education intervention, their education needs, and preferred sources and modes of such education. Method: The intervention was carried out during the last class of a public health prenatal education series. A total of 31 first-time expectant parents participated and included both women (N = 16) and men (N = 15; mean, 29 years). The intervention was an in-person session on the topics of a safe sleeping environment, shaken baby syndrome, physical punishment risks and positive parenting, and expected development and safety. Participants completed the Infant Safety Education Project Questionnaire after the intervention. Results: Overall, most participants in this study found the content useful, planned to use it in caring for their infant, and indicated that this information should be shared with all expectant parents. Discussion: Findings support a larger scale study to determine parent education needs of expectant parents and the development, implementation, and evaluation of programming. Pediatric nurse practitioners and other primary care practitioners should be aware of the education needs of expectant parents and be prepared to provide anticipatory guidance and resources as appropriate. © 2013 National Association of Pediatric Nurse Practitioners.

Vriend J.,University of Manitoba | Reiter R.J.,Health Science University
Molecular and Cellular Endocrinology | Year: 2015

Both melatonin and proteasome inhibitors upregulate antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GP), hemoxygenase 1 (HO-1), and NADPH:quinone oxidoreductase (NQO1). Recent evidence suggests that the antioxidant action of both melatonin and proteasome inhibitors involves the Keap1-ARE (Keap1 antioxidant response element) pathway via the upregulation of Nrf2. Melatonin and proteasome inhibitors suppress the degradation of Nrf2 and also enhance its nuclear translocation. In the nucleus Nrf2, together with a cofactor, stimulates the transcription of antioxidant enzymes and detoxifying enzymes. The ligase (E3) complex (Keap1-Cul3-Rbx1) responsible for ubiquitinating Nrf2, prior to proteasomal degradation, also ubiquitinates IkB kinase and the antiapoptotic factor Bcl-2, and possibly additional proteins. In various systems, NF-κB, which is inhibited by IkBα, is downregulated by proteasome inhibitors as well as by melatonin. Similarly in leukemic cells, Bcl-2 is down-regulated by the proteasome inhibitor, bortezomib, and also by melatonin. Thus melatonin administration modulates the activity of three separate substrates of the Keap1-Cul3-Rbx1 ubiquitin ligase. These facts could be accounted for by the hypothesis that melatonin interacts with the ubiquitin ligase complex or, more likely, by the hypothesis that melatonin acts as a proteasome inhibitor. A recent study documented that melatonin acts as a proteasome inhibitor in cancer cells as well as inhibiting chymotrypsin-like activity in cell-free systems of these cells. Further studies, however, are needed to clarify the interaction of melatonin and the ubiquitin-proteasome system as they relate to oxidative stress. © 2014 Elsevier Ireland Ltd.

Majumdar S.R.,University of Alberta | Ezekowitz J.A.,University of Alberta | Lix L.M.,University of Saskatchewan | Leslie W.D.,University of Manitoba
Journal of Clinical Endocrinology and Metabolism | Year: 2012

Objective: The aim of the study was to determine whether heart failure is associated with an increased risk of major osteoporotic fractures that is independent of bone mineral density (BMD). Methods:Weconducted a population-based cohort study in Manitoba, Canada, by linking a clinical registry of all adults 50 yr ofageandolderwhounderwentinitialBMDtestingfrom1998- 2009 with administrative databases. We collected osteoporosis risk factors, comorbidities, medications, and BMD results. Validated algorithms identified recent-onset heart failure before the BMD test and new fractures after. The main outcome was time to major osteoporotic fractures (i.e. clinical vertebrae, distal forearm, humerus, and hip), and multivariable proportional hazards models were used for analyses. Results: The cohort consisted of 45,509 adults; 1,841 (4%) had recent-onset heart failure. Subjects with heart failure were significantly (P<0.001) older (74 vs. 66 yr) and had more previous fractures (21 vs. 13%) and lower total hip BMD [T-score, -1.3 (SD 1.3) vs. -0.9 (SD 1.2)] than those without. There were 2703 incident fractures over the 5-yr observation. Overall,10%of heart failure subjects had incident major fractures compared with 5% of those without [unadjusted hazard ratio (HR), 2.45; 95% confidence interval (CI), 2.11-2.85]. Adjustment for osteoporosis risk factors, comorbidities, and medications attenuated but did not eliminate this association (HR, 1.33; 95% CI, 1.11-1.60), nor did further adjustment for total hip BMD (HR, 1.28; 95% CI, 1.06-1.53). Conclusions: Heart failure is associated with a 30% increase in major fractures that is independent of traditional risk factors and BMD, and it also identifies a high-risk population that may benefit from increased screening and treatment for osteoporosis. Copyright © 2012 by The Endocrine Society.

Ng A.K.Y.,University of Manitoba | Padilha F.,Tembo Solutions | Pallis A.A.,University of Aegean
Journal of Transport Geography | Year: 2013

Many research works on dry ports, associated dry ports with enhanced seaport efficiency, relieving congestion without (significant) capacity expansion. Also, they posited how dry ports being essential elements in the competitive position of seaports, as they acted to facilitate access to (overlapping) hinterlands. However, those focusing on how institutions could strengthen (or dissipate) the bureaucratic and logistical roles of dry ports had remained scarce, especially on developing economies. Hence, through investigating the recent development of dry ports in four Brazilian states, the paper investigates how institutional framework affects the bureaucratic and logistical roles of dry ports in emerging economies. The paper posits that the Brazilian institutional framework in place has acted as causal factors in strengthening the bureaucratic roles of dry ports while at the same time dissipating their logistical roles. Through establishing the causal relation between these forces, the paper provides important insight on the impacts of institutions on transportation and regional development in different geographical regions. © 2012 Elsevier Ltd.

Vriend J.,University of Manitoba | Reiter R.J.,University of Texas Health Science Center at San Antonio
Journal of Pineal Research | Year: 2015

The expression of 'clock' genes occurs in all tissues, but especially in the suprachiasmatic nuclei (SCN) of the hypothalamus, groups of neurons in the brain that regulate circadian rhythms. Melatonin is secreted by the pineal gland in a circadian manner as influenced by the SCN. There is also considerable evidence that melatonin, in turn, acts on the SCN directly influencing the circadian 'clock' mechanisms. The most direct route by which melatonin could reach the SCN would be via the cerebrospinal fluid of the third ventricle. Melatonin could also reach the pars tuberalis (PT) of the pituitary, another melatonin-sensitive tissue, via this route. The major 'clock' genes include the period genes, Per1 and Per2, the cryptochrome genes, Cry1 and Cry2, the clock (circadian locomotor output cycles kaput) gene, and the Bmal1 (aryl hydrocarbon receptor nuclear translocator-like) gene. Clock and Bmal1 heterodimers act on E-box components of the promoters of the Per and Cry genes to stimulate transcription. A negative feedback loop between the cryptochrome proteins and the nucleus allows the Cry and Per proteins to regulate their own transcription. A cycle of ubiquitination and deubiquitination controls the levels of CRY protein degraded by the proteasome and, hence, the amount of protein available for feedback. Thus, it provides a post-translational component to the circadian clock mechanism. BMAL1 also stimulates transcription of REV-ERBα and, in turn, is also partially regulated by negative feedback by REV-ERBα. In the 'black widow' model of transcription, proteasomes destroy transcription factors that are needed only for a particular period of time. In the model proposed herein, the interaction of melatonin and the proteasome is required to adjust the SCN clock to changes in the environmental photoperiod. In particular, we predict that melatonin inhibition of the proteasome interferes with negative feedback loops (CRY/PER and REV-ERBα) on Bmal1 transcription genes in both the SCN and PT. Melatonin inhibition of the proteasome would also tend to stabilize BMAL1 protein itself in the SCN, particularly at night when melatonin is naturally elevated. Melatonin inhibition of the proteasome could account for the effects of melatonin on circadian rhythms associated with molecular timing genes. The interaction of melatonin with the proteasome in the hypothalamus also provides a model for explaining the dramatic 'time of day' effect of melatonin injections on reproductive status of seasonal breeders. Finally, the model predicts that a proteasome inhibitor such as bortezomib would modify circadian rhythms in a manner similar to melatonin. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Blakley B.W.,University of Manitoba
Otology and Neurotology | Year: 2016

Objective: The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) recently published guidelines on the treatment of tinnitus. This paper examines the possible impact of those guidelines on otologic practice. Design: A survey was sent to the members of the American Neurotology Society before and after the publication of Clinical practice guideline: tinnitus. The goals of this study were to see if the guidelines changed attitudes of otologists, confirm what treatments and explanations are being used in the field before and after the guidelines were published. Main Outcomes: Five hundred fifty-eight surveys were sent out and there were 216 responses. Otologists generally seemed to practice in accordance with the recommendations of the guidelines even before these were published. Drugs and sound therapies were not commonly used for primary tinnitus either before or after publication of the guidelines. One treatment that otologists seemed to have confidence in that was omitted from the guidelines was surgical treatment of hearing loss. Conclusion: Opinions regarding the treatment of tinnitus vary considerably. The AAO-HNS clinical practice guideline: tinnitus has not significantly altered the practices of otologists, but the guidelines provide meaningful, important information for other clinicians who deal infrequently with tinnitus. Copyright © 2016 Otology & Neurotology, Inc.

Nicolle L.E.,University of Manitoba
Infection Control and Hospital Epidemiology | Year: 2016

In this issue of ICHE, Fakih et al1 argue that a metric of catheter days as a proportion of all patient days should be introduced as an additional performance measure for monitoring indwelling urinary catheter harms. Catheteracquired urinary tract infection (CAUTI) is one of the most common healthcare-acquired infections. Interest in infection prevention and control of CAUTI was relatively quiescent for many decades, but the past several years have seen renewed interest and substantial activity addressing the issue. An important catalyst for this attention occurred in October 2008 with the US Centers for Medicare and Medicaid Services implementation of a policy that hospitals would not be reimbursed for costs of CAUTIs acquired by hospitalized patients.2 This policy was justified on the basis of an assessment that a substantial proportion of these infections were “reasonably preventable” adverse effects of hospitalization. Following closely on this change, the US Department of Health and Human Services National Action Plan to Prevent Health Care Associated Infections identified CAUTI reduction as 1 of the 8 initial metrics in the “Roadmap to Elimination.” The heightened attention to CAUTI both in the United States and globally is appropriate. In fact, little substantive progress in the prevention of CAUTI had occurred since the description of closed urinary drainage in 1960, and the 1983 CDC Guidelines for Prevention of Catheter-Associated Urinary Tract Infections were still being used by Infection Prevention and Control programs in 008. The “new normal” is an environment in which CAUTI is a priority for infection prevention, and programs have been developed to achieve specific goals in limiting the frequency of adverse events from urinary catheters. © 2015 by The Society for Healthcare Epidemiology of America. All rights reserved.

Le M.-L.,University of Manitoba
Health Information and Libraries Journal | Year: 2014

Background: The number of public health degrees and programmes is growing rapidly. This means that a diverse and multidisciplinary group of students are in need of expert library services to navigate the complicated world of public health information. Objective: To better understand the information needs of public health students, a group that has not previously been studied in the information needs literature. Methods: An online survey. Results: Of the 153 students, 38 responded (25% response rate). Their responses indicated a strong need for more tailored library instruction sessions at the point of need as opposed to general stand-alone sessions offered at the beginning of a term. It was also found that many students were unaware of public health specific resources available that could greatly aid them in their information needs. Suggestions were made on how to improve the library subject guide, specifically in the areas of more instructions related to locating hard to find resources (e.g. statistics, grey literature), and direct linking to resources (e.g. databases and relevant articles). Conclusion: The information needs of public health students are diverse and complex. It is imperative that the library has a solid understanding of their needs and is able to offer them targeted and relevant library services. © 2014 Health Libraries Journal.

Qin G.,Chinese Academy of Sciences | Shalchi A.,University of Manitoba
Physics of Plasmas | Year: 2014

In the present paper, we re-visit a well-known problem in diffusion theory, namely the 90° scattering problem. We use a test-particle code to compute the pitch-angle Fokker-Planck coefficient at 90° for different values of the turbulent magnetic field strength and the magnetic rigidity. We consider a slab model and compare our numerical findings with the analytical result provided by second-order quasilinear theory. We show that the latter theory accurately describes 90° scattering. We also replace the slab model by a more realistic two-component model to explore the influence of the turbulence model on 90° scattering. © 2014 AIP Publishing LLC.

Piyadasa C.K.G.,University of Manitoba
Optics Communications | Year: 2012

The paper shows that the boundary diffraction wave originating at an edge is an omnidirectional cylindrical wave. The experimental set-up used to demonstrate this property employs a He-Ne laser beam. The beam is split into three beams using a glass plate. One of the beams passes straight through, the second beam passes through the glass plate and the third beam is the reflected beam. It is shown that the interference patterns are observed in all three beams. Analysis of these patterns shows that the boundary diffraction wave originating from the edge is an omnidirectional cylindrical wave. This analysis also provides strong evidence that the boundary diffraction wave travels not only within the beam where it originates but also to the neighboring coherent beam. The energy re-distribution was also shown to be dependent on the wavelength of the incident light beam and hence provides further evidence as to why longer wave lengths disperse more compared to shorter wavelengths in white light diffraction by an edge. © 2012 Elsevier B.V. All rights reserved.

Sanchez G.V.,George Washington University | Master R.N.,Quest Diagnostics Nichols Institute | Karlowsky J.A.,University of Manitoba | Bordon J.M.,Section of Infectious Disease
Antimicrobial Agents and Chemotherapy | Year: 2012

This study examines in vitro antimicrobial resistance data from Escherichia coli isolates obtained from urine samples of U.S. outpatients between 2000 and 2010 using The Surveillance Network (TSN). Antimicrobial susceptibility results (n = 12,253,679) showed the greatest increases in E. coli resistance from 2000 to 2010 for ciprofloxacin (3% to 17.1%) and trimethoprim-sulfamethoxazole (TMP-SMX) (17.9% to 24.2%), whereas nitrofurantoin (0.8% to 1.6%) and ceftriaxone (0.2% to 2.3%) showed minimal change. From 2000 to 2010, the antimicrobial resistance of urinary E. coli isolates to ciprofloxacin and TMP-SMX among outpatients increased substantially. Copyright © 2012, American Society for Microbiology. All Rights Reserved.

Safneck J.R.,University of Manitoba
Saudi Journal of Ophthalmology | Year: 2012

Endophthalmitis is a feared complication of trauma, surgical procedures and septicemia. Although uncommon, its potential for significant visual loss is well recognized. Especially over the past decade, complicated surgeries and medical techniques have increased and seriously ill patients are being sustained in ever increasing numbers. New pathogens are being recognized and known ones reclassified thanks to advances in molecular analysis. Continuously evolving PCR methodologies also add a new dimension to the diagnosis of infectious endophthalmitis. As well, medical literature is now truly international, encompassing studies from around the world that expand our understanding of ocular infectious disease. This report reviews some of these changes as they relate to endophthalmitis and particularly to the spectrum of organisms involved. © 2012 King Saud University.

Liver fibrosis and hepatocellular carcinoma (HCC) are emerging health problems worldwide. Number of death due to HCC was steadily increased during the last decade. Although liver fibrosis and HCC have been investigated extensively, there are no successful and/or satisfactory therapies especially for patients with HCC. From our understanding of both Western medicine and Chinese medicine, it could identify the targets in liver fibrosis and HCC for intervention with Chinese medicine such as bone morphogenetic protein 4 (BMP-4). BMP-4 expression was significantly increased in both liver fibrosis and HCC and saponin class of certain Chinese herbs could regulate its expression. Therefore, BMP-4 could be one of the targets for treatment of liver fibrosis and HCC from integrative medicine. ©The Chinese Journal of Integrated Traditional and Western Medicine Press and Springer-Verlag Berlin Heidelberg 2012.

McCubbin J.A.,University of Winnipeg | Krokhin O.V.,University of Manitoba
Tetrahedron Letters | Year: 2010

Electron-rich aromatic and heteroaromatic rings are functionalized directly with a variety of benzylic alcohols under mild conditions. The reaction is catalyzed by commercially available pentafluorophenylboronic acid, which is stable under ambient conditions and recoverable. The reaction itself is highly atom economical and produces water as the only byproduct. A Friedel-Crafts mechanism is proposed. © 2010 Elsevier Ltd. All rights reserved.

Lobb D.A.,University of Manitoba
Journal of Soil and Water Conservation | Year: 2011

Over the past few decades, a tremendous amount of time and money has gone into developing and applying technologies to manage crop variability within fields. Table 1 lists in order the factors that most commonly cause crop variability. The information in this table was developed by Aspinall (1997) based on several years of experience in southern Ontario, and it is considered to apply to many other agricultural regions. Clearly, there are many causes of crop variability, and several are either directly or indirectly linked to soil erosion. The purpose of this paper is to bring attention to soil erosion as a cause of soil landscape variability and to the potential to affect crop variability by managing soil erosion. The underlying message is that sound management of variable soil landscapes requires a balanced approach-the causes of the variability must be managed as well as the effects. © 2011 Soil and Water Conservation Society. All rights reserved.

Perera N.,ERL Phase Power Technologies | Rajapakse A.D.,University of Manitoba
IEEE Transactions on Power Delivery | Year: 2013

This paper presents the development of a new protection method for series-compensated double-circuit transmission lines using current transients. Using the proposed method, the faulted circuit can be identified locally, by comparing the polarities of wavelet coefficients of the branch currents. Applicability of the proposed method is demonstrated using a 500-kV transmission system simulated in an electromagnetic transient simulation program. Comparisons with the conventional distance and phase comparison protection schemes show that the proposed method can provide faster and more reliable protection for the series-compensated double-circuit transmission systems. The security of the relay can be further enhanced if the fault direction information is exchanged between the relays at two ends. © 1986-2012 IEEE.

Shalchi A.,University of Manitoba
Physics of Plasmas | Year: 2015

A fundamental problem in plasma and astrophysics is the interaction between energetic particles and magnetized plasmas. In the current paper, we focus on particle diffusion across the guide magnetic field. It is shown that the perpendicular diffusion coefficient depends only on the parallel diffusion coefficient and the Kubo number. Therefore, one can find four asymptotic limits depending on the values of these two parameters. These regimes are the quasilinear limit, the Kadomtsev and Pogutse limit, the scaling of Rechester and Rosenbluth, and the scaling found by Zybin and Istomin. In the current article, we focus on the Rechester and Rosenbluth scenario because this was not discovered before in the context of collisionless plasmas. Examples and applications are discussed as well. We show that an energy independent ratio of perpendicular and parallel diffusion coefficients can be found and that this ratio can be very small but also close to unity. This is exactly what one observes in the solar wind. © 2015 AIP Publishing LLC.

Tkachuk G.A.,University of Manitoba | Harris C.A.,Ottawa Hospital Cancer Center
Journal of Pain | Year: 2012

The aim of this study was to investigate the psychometric properties of an abbreviated version of the Tampa Scale for Kinesiophobia (TSK) in a clinical sample of patients with chronic pain. Chronic pain patients (n = 276) seeking treatment at an interdisciplinary treatment center completed self-report questionnaires including the TSK-13, and 2 tests of physical functioning. Four competing models of the TSK were tested using confirmatory factor analysis. Internal consistency was assessed, as were discriminant evidence of construct validity and concurrent criterion-related validity. Incremental validity was assessed with hierarchical multiple regressions controlling for pain severity. The analyses indicated that an 11-item, 2-factor structure best fit the data. The first factor, somatic focus, consisted of 5 items, while the second factor, activity avoidance, was comprised of 6 items. The TSK-11 scales demonstrated acceptable levels of internal consistency, as well as evidence of discriminant, concurrent criterion-related, and incremental validity. Somatic focus uniquely predicted perceived disability while activity avoidance uniquely predicted actual physical performance, controlling for pain severity. The 2-factor structure of the TSK-11 was found to be a brief, reliable, and valid measure of fear of movement/(re)injury for chronic pain patients. We recommend that the TSK-11 be used in future research and in clinical settings. Perspective: In this study, confirmatory factor analysis identified the 2-factor TSK-11 as the best fitting model of TSK factor structure. The TSK-11 is a brief, reliable, and valid measure of fear of movement/(re)injury for chronic pain patients. © 2012 by the American Pain Society.

Blydt-Hansen T.D.,University of Manitoba
Clinical Journal of the American Society of Nephrology | Year: 2014

Background and objectives: The complexity of CKD management in children is increased by the number of comorbid conditions. This study assessed the prevalence of comorbidities in pediatric CKD and the frequency with which multiple comorbidities present together by assessing prevalent medication use by CKD stage and diagnosis and their association with clinical or sociodemographic factors. The association between number and frequency of dosing of medications prescribed and self-report of nonadherence was also assessed. Design, setting, participants, & measurements: In this cross-sectional analysis of the Chronic Kidney Disease in Children study, medication use at study entry grouped by indication was examined by CKD stage, diagnosis, age, race, ethnicity, income, and CKD duration. Multivariate adjusted predictors of medication use and clustering were examined. Nonadherence was assessed by self-report of missed medications in the past 7 days. Results: The 558 eligible participants had a median age of 11 years and median GFR of 44 ml/min per 1.73 m2; 62% of participants were male and 78% had nonglomerular kidney disease. The number of medications for treatment of CKD comorbidities increased with advanced CKD stage (2.5-fold for stages IV versus II; P<0.001) and glomerular disease (1.4-fold versus nonglomerular; P<0.001). Three distinct medication clusters were identified that corresponded to treatment of glomerular disease, advanced renal tubular dysfunction, and proteinuric complications, respectively. Nonadherence was associated with increased medication dosing frequency (administration >2 times/d; P<0.001) but not the number of medications. Conclusions: Medical therapy for children with CKD is complex and is affected by glomerular diagnosis, CKD stage, and medication frequency. The need for CKD-related medication treatment cannot be easily predicted by CKD staging alone. Poorer adherence was associated with increased medication frequency, but not with the number of medical problems needing treatment. Consolidating medical treatment and reducing medication frequency may improve adherence rates in children with CKD. © 2014 by the American Society of Nephrology.

Shen G.X.,University of Manitoba
Cardiovascular and Hematological Disorders - Drug Targets | Year: 2012

The prevalence of diabetes has been rapidly increasing in world-wide countries. The dominant cause of mortality in diabetic patients is cardiovascular complications. Mechanism for the susceptibility of diabetic patients to cardiovascular disorders remains unclear. Elevated oxidative stress was detected in diabetic patients or in animal models. Mitochondria are one of major sources of reactive oxygen species (ROS) in cells. Mitochondrial dysfunction and DNA mutations have been detected in diabetic patients. Diabetes-associated metabolic disorders, including hyperglycemia, hypertriglyceridemia, hypercholesterolemia, hypoalphalipoproteinemia, and increased levels of advanced glycation end products, glycated and oxidized lipoproteins, are associated with oxidative stress. Glycated or oxidized low density lipoproteins (LDL) impair the activities of mitochondrial respiratory chain complex enzymes in vascular endothelial cells (EC). Dysfunction in mitochondrial respiration may increase the formation of ROS in mitochondria. NADPH oxidase (NOX) generates ROS in cytosol. Increased NOX activity was detected in diabetic patients. Glycated and oxidized LDL increase the expression of NOX and ROS production in EC. Diabetes-associated metabolic disorders may lead to mitochondrial dysfunction, NOX activation and excess ROS production, which results in oxidative stress and promotes cardiovascular disorders in diabetic patients. Statins, metformin and anthocyanidins may help to attenuate oxidative stress in vasculature induced by diabetes-associated metabolic disorders. © 2012 Bentham Science Publishers.

Safronetz D.,National Institute of Allergy and Infectious Diseases | Feldmann H.,National Institute of Allergy and Infectious Diseases | Feldmann H.,University of Manitoba | De Wit E.,National Institute of Allergy and Infectious Diseases
Annual Review of Pathology: Mechanisms of Disease | Year: 2015

Emerging infectious diseases of zoonotic origin are shaping today's infectious disease field more than ever. In this article, we introduce and review three emerging zoonotic viruses. Novel hantaviruses emerged in the Americas in the mid-1990s as the cause of severe respiratory infections, designated hantavirus pulmonary syndrome, with case fatality rates of around 40%. Nipah virus emerged a few years later, causing respiratory infections and encephalitis in Southeast Asia, with case fatality rates ranging from 40% to more than 90%. A new coronavirus emerged in 2012 on the Arabian Peninsula with a clinical syndrome of acute respiratory infections, later designated as Middle East respiratory syndrome (MERS), and an initial case fatality rate of more than 40%. Our current state of knowledge on the pathogenicity of these three severe, emerging viral infections is discussed. © 2015 by Annual Reviews.

Alexander M.J.L.,University of Manitoba
Journal of Strength and Conditioning Research | Year: 2012

2012-Landing awkwardly from a jump is a common mechanism of injury for the anterior cruciate ligament (ACL) of the knee. Augmented feedback, such as verbal or visual instruction, has been shown to cause an immediate, positive change in landing biomechanics in a laboratory setting. No data exist on the longer term effects of feedback on jump landing biomechanics in a sports-specific setting. The purpose of this study was to explore whether providing video and verbal feedback to adolescent (12-14 years old) female volleyball athletes would improve their landing technique. Trunk and lower extremity kinematic variables were measured in 19 participants before a feedback session was provided to the intervention group (IG). Follow-up kinematic measurements of the IG were taken immediately postintervention, and again after 2 and 4 weeks. Two-way repeated measures analysis of variance (ANOVA) was used to compare the IG with a control group (CG), who received no feedback. The IG (n = 10) demonstrated increased maximal hip and trunk flexion compared with the CG (n = 9) at week 4 (p ≤ 0.05). One-way repeated measures ANOVA was used to determine if changes were evident within the IG over time. Ankle dorsiflexion, right knee and hip flexion, and trunk flexion changed significantly (p ≤ 0.05) over the 4-week period. Augmented feedback appeared to produce a positive change in landing biomechanics in adolescent female volleyball athletes performing a sportsspecific skill. Courtside video and verbal feedback may present a relatively simple, cost-effective method of introducing one component of a comprehensive ACL injury prevention program at a young age. © 2012 National Strength and Conditioning Association.

A new nonlinear theory for cosmic-ray scattering across the mean magnetic field is derived. This theory can be applied for arbitrary turbulence geometry. Previous theories such as the extended nonlinear guiding center theory are deduced as special limits. Furthermore, the new theory can explain subdiffusive transport for slab turbulence and the recovery of diffusion for slab/two-dimensional and three-dimensional turbulence. The nonlinear standard theory for field line wandering can be obtained as a special limit. © 2010. The American Astronomical Society. All rights reserved.

Simons F.E.R.,University of Manitoba
Allergy: European Journal of Allergy and Clinical Immunology | Year: 2011

Anaphylaxis is a serious allergic reaction that is rapid in onset and sometimes leads to death. Understanding mechanisms, triggers, and patient-specific risk factors for severe or fatal anaphylaxis is critically important. Diagnosis of anaphylaxis is currently based on established clinical criteria. Epinephrine (adrenaline) is the first-line medication for anaphylaxis treatment and delay in injecting it contributes to biphasic reactions, hypoxic-ischemic encephalopathy, and fatality. Here, we focus on four important areas of translational research in anaphylaxis: studies of potential new biomarkers to support the clinical diagnosis of anaphylaxis, laboratory tests to distinguish allergen sensitization from clinical risk of anaphylaxis, the primary role of epinephrine (adrenaline) in anaphylaxis treatment, and strengthening the overall evidence base for anaphylaxis treatment. © 2011 John Wiley & Sons A/S.

Portet S.,University of Manitoba
Journal of Theoretical Biology | Year: 2013

An aggregation model with explicit expression of association rate constants is considered to study in vitro type III intermediate filament length distribution dynamics. Different assumptions on the properties of filaments and probability of aggregation are considered, leading to four models. Fitting of model responses to experimental data leads to the identification of the most appropriate model to represent each time point of the assembly. A combination of models allows the construction of a mixed model that represents well the complete assembly dynamics: it is found that the rate constants decrease with respect to filament size when the aggregation involves at least one short filament, whereas for longer filaments they are almost independent of size. The flexible nature of filaments is thus important in the assembly of intermediate filaments. © 2013 Elsevier Ltd.

Agusto F.B.,Austin Peay State University | Gumel A.B.,University of Manitoba
Mathematical Biosciences | Year: 2013

A new deterministic model for the transmission dynamics of the lowly- and highly-pathogenic avian influenza (LPAI and HPAI) strains is designed and rigorously analyzed. The model exhibits the phenomenon of backward bifurcation, where a stable disease-free equilibrium co-exists with a stable endemic equilibrium whenever the associated reproduction number is less than unity. It is shown that the re-infection of birds infected with the LPAI strain causes the backward bifurcation phenomenon. In the absence of such re-infection, the disease-free equilibrium of the model is globally-asymptotically stable when the associated reproduction number is less than unity. Using non-linear Lyapunov functions of Goh-Volterra type, the LPAI-only and HPAI-only boundary equilibria of the model are shown to be globally-asymptotically stable when they exist. A special case of the model is shown to have a continuum of co-existence equilibria whenever the associated reproduction numbers of the two strains are equal and exceed unity. Furthermore, numerical simulations of the model suggest that co-existence or competitive exclusion of the two strains can occur when the respective reproduction numbers of the two strains exceed unity. © 2013 Elsevier Inc.

Acar E.F.,University of Toronto | Acar E.F.,University of Manitoba | Sun L.,University of Toronto
Biometrics | Year: 2013

Motivated by genetic association studies of SNPs with genotype uncertainty, we propose a generalization of the Kruskal-Wallis test that incorporates group uncertainty when comparing k samples. The extended test statistic is based on probability-weighted rank-sums and follows an asymptotic chi-square distribution with k - 1 degrees of freedom under the null hypothesis. Simulation studies confirm the validity and robustness of the proposed test in finite samples. Application to a genome-wide association study of type 1 diabetic complications further demonstrates the utilities of this generalized Kruskal-Wallis test for studies with group uncertainty. The method has been implemented as an open-resource R program, GKW. © 2013, The International Biometric Society.

Duan W.H.,Monash University | Wang Q.,University of Manitoba
ACS Nano | Year: 2010

Transportation of water molecules in a carbon nanotube based on an energy pump concept is investigated by molecular dynamics simulations. A small portion of the initially twisted wall of a carbon nanotube is employed to function as an energy pump for possible smooth transportation of water molecules. The momentum and resultant force on a water molecule and the corresponding displacement and velocity of the molecule are particularly studied to disclose the transportation process. The efficiency of the transportation is found to be dependent on the size of the energy pump. Once the process for the transportation of one molecule is elucidated, transportations of 20 water molecules are simulated to investigate the effect of the environmental temperature and fluctuations in the nanotube channel on the transportation. It is revealed that the accelerated period of multiple water molecules is longer than that in the transportation of a single water molecule. In addition, the fluctuations in the nanotube wall due to the buckling propagation and a higher environmental temperature will all lead to obvious decreases in the water velocity and hence retard the transportation process. © 2010 American Chemical Society.

Shalchi A.,University of Manitoba
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2013

In the present paper we revisit the problem of perpendicular diffusion in magnetostatic slab turbulence. It is shown that the particles cannot be scattered away from the magnetic field line by more than an unperturbed Larmor radius. This result confirms the theorem on reduced dimensionality proposed earlier for this special case. Furthermore, we estimate the motion of the particles away from the field line often called microscopic diffusion. The relation between the microscopic diffusion coefficient derived in the present paper and well-known results such as classical scattering theory and Bohm diffusion is also discussed. © 2013 Elsevier Ltd.

Pemberton T.J.,University of Manitoba | Rosenberg N.A.,Stanford University
Human Heredity | Year: 2014

Background/Aims: Culturally driven marital practices provide a key instance of an interaction between social and genetic processes in shaping patterns of human genetic variation, producing, for example, increased identity by descent through consanguineous marriage. A commonly used measure to quantify identity by descent in an individual is the inbreeding coefficient, a quantity that reflects not only consanguinity, but also other aspects of kinship in the population to which the individual belongs. Here, in populations worldwide, we examine the relationship between genomic estimates of the inbreeding coefficient and population patterns in genetic variation. Methods: Using genotypes at 645 microsatellites, we compare inbreeding coefficients from 5,043 individuals representing 237 populations worldwide to demographic consanguinity frequency estimates available for 26 populations as well as to other quantities that can illuminate population-genetic influences on inbreeding coefficients. Results: We observe higher inbreeding coefficient estimates in populations and geographic regions with known high levels of consanguinity or genetic isolation and in populations with an increased effect of genetic drift and decreased genetic diversity with increasing distance from Africa. For the small number of populations with specific consanguinity estimates, we find a correlation between inbreeding coefficients and consanguinity frequency (r = 0.349, p = 0.040). Conclusions: The results emphasize the importance of both consanguinity and population-genetic factors in influencing variation in inbreeding coefficients, and they provide insight into factors useful for assessing the effect of consanguinity on genomic patterns in different populations. © 2014 S. Karger AG, Basel.

Pitch-angle scattering, parallel spatial diffusion, and stochastic acceleration of cosmic rays are investigated analytically. Based on a second-order quasilinear theory, we derive analytical expressions for the aforementioned transport parameters for all possible magnetic field strengths and particle energies. This work complements previous work where only parallel diffusion for low energetic particles was considered. Furthermore, we compute the first time the momentum diffusion coefficient. It is also shown that the relation between the momentum diffusion coefficient and the parallel spatial diffusion coefficient is more complicated than assumed in previous work. © 2012 American Institute of Physics.

Bellan L.,University of Manitoba
Canadian Journal of Ophthalmology | Year: 2012

Objective: To examine the ability of recent Canadian ophthalmology graduates to commence clinical practice and obtain surgical privileges. A secondary objective was to assess their perception of the adequacy of their residency training. Design: An Internet questionnaire survey. Participants: Canadian graduates of Canadian ophthalmology residency programs between 2005 and 2009, inclusive. Methods: Email addresses for the participants were obtained from the Canadian Ophthalmological Society and invitations to participate were sent, followed by 2 reminder emails. Results: A 44% response rate was obtained (65 out of 154 emails sent). Of the respondents, 91% were working full time, and 89% had operating-room time. Training was adequate for all CanMEDs competencies except working as a manager. Assessment that one's practice did not live up to expectations correlated with male gender, dissatisfaction with location, inability to get operating-room time, inability to get other hospital resources, feelings about fairness of distribution of resources, and net income below expectations. Conclusions: For the most part, recent graduates are successful in establishing practices that meet their expectations. Training in management skills should be improved in residency programs. © 2012 Canadian Ophthalmological Society.

Bannerman J.A.,University of Manitoba | Roitberg B.D.,Simon Fraser University
Oikos | Year: 2014

Climate change is predicted to increase the occurrence of extreme temperature events. We constructed a stage-structured Leslie matrix model with intra-generational dynamics to explore the impact of extreme and fluctuating temperatures on host-parasitoid dynamics. We varied three temperature parameters to generate a range of temperature regimes that varied in their daily maximum temperatures, the number of warmer-than-average days and the autocorrelation of those warmer-than-average days. All three temperature parameters influenced host-parasitoid dynamics. Increasing the frequency of warmer than average days and the degree of autocorrelation only exerted significant impacts on host- parasitoid dynamics when daily maximum temperatures were sufficient to produce temperature-dependent mortality. The effects of increasing autocorrelation of daily temperatures were dependent on the maximum daily temperatures and the frequency of warmer than average days. When daily maximum temperatures were severely warm, but the frequency of those severely warm days was low, increasing autocorrelation increased the probability that the aphids and parasitoids will persist, but when the frequency of severely warm days is increased, increasing autocorrelation decreases the probability that the populations will persist. These temperature phenomena exert significant effects on host-parasitoid dynamics in addition to those effects produced by changes in mean temperatures and warrant further investigation at the community level. © 2013 The Authors.

Recent evidence suggests that a rare-cell population with a stem cell phenotype maintains breast tumors. Therefore, to devise breast cancer therapies that are more effective, we need to understand the unique biology of these cancer stem cells. Currently, very little is known about the origin of cancer stem cells and their relationship to the tumor phenotype. A recent study from Smalley's group demonstrates that targeting an inactivating Brca1 mutation to the luminal progenitors could yield basal-like breast cancers. This observation suggests that the inherent plasticity of the primitive cells can be hijacked by the tumorigenic processes to produce tumors with an unpredictable phenotype. © 2010 BioMed Central Ltd.

Smil V.,University of Manitoba
Population and Development Review | Year: 2011

The human species has evolved to dominate the biosphere: global anthropomass is now an order of magnitude greater than the mass of all wild terrestrial mammals. As a result, our dependence on harvesting the products of photosynthesis for food, animal feed, raw materials, and energy has grown to make substantial global impacts. During the past two millennia these harvests, and changes of land use due to deforestation and conversions of grasslands and wetlands, have reduced the stock of global terrestrial plant mass by as much as 45 percent, with the twentieth-century reduction amounting to more than 15 percent. Current annual harvests of phytomass have been a significant share of the global net primary productivity (NPP, the total amount of new plant tissues created by photosynthesis). Some studies put the human appropriation of NPP (the ratio of these two variables) as high as 40 percent but the measure itself is problematic. Future population growth and improved quality of life will result in additional claims on the biosphere, but options to accommodate these demands exist without severely compromising the irreplaceable biospheric services. © 2011 The Population Council, Inc.

Martens P.J.,University of Manitoba
Journal of Human Lactation | Year: 2012

Background: Kramer et als PROBIT (Promotion of Breastfeeding Intervention Trial) research in Belarus studied effects of the Baby-Friendly Hospital Initiative (BFHI) training on breastfeeding duration, exclusivity, and health outcomes. Aims: To critique inclusion criteria, context, approaches to data analysis, and health outcome results. Method: Twenty-two articles were retrieved from PubMed and the PROBIT Website for 2001-2010; 6 were excluded as not focusing on breastfeeding and health outcomes. Results: PROBIT data from the cluster randomized hospital comparisons included only breastfed babies since all nonbreastfed babies were excluded from the research. Context may affect outcomes, knowing that Belarus has good basic health services, 3-year maternity leaves with little use of daycare, 95% breastfeeding initiation rate, and a well-educated population. PROBIT data were analyzed in 2 ways: (a) intent-to-treat analyses of breastfeeding and health differences by cluster randomized intervention and control site mother/baby pairs; and (b) as an observational cohort study of health outcomes for all mother/baby pairs, analyzed by various breastfeeding categorizations and controlling for biases. PROBIT demonstrated links between BFHI and longer breastfeeding duration (19.7% vs 11.4% at 12 months, P < .001) and exclusivity (43.3% vs 6.4% at 3 months, P < .001), reductions in gastrointestinal episodes and rashes, higher verbal IQ scores, and longer exclusive breastfeeding rates for subsequent children but no statistically significant differences in the childs body mass index, blood pressure, or dental health. Conclusion: PROBIT provides foundational evidence for BFHI policy and follow-up care. Knowing that non-breastfed babies were excluded, caution must be exercised for health comparisons. © The Author(s) 2012.