National University of La Jolla
National University of La Jolla
Boassa D.,National University of La Jolla |
Nguyen P.,National University of La Jolla |
Hu J.,National University of La Jolla |
Ellisman M.H.,National University of La Jolla |
And 3 more authors.
Frontiers in Cellular Neuroscience | Year: 2015
Pannexin2 (Panx2) is the largest of three members of the pannexin proteins. Pannexins are topologically related to connexins and innexins, but serve different functional roles than forming gap junctions. We previously showed that pannexins form oligomeric channels but unlike connexins and innexins, they form only single membrane channels. High levels of Panx2 mRNA and protein in the Central Nervous System (CNS) have been documented. Whereas Pannexin1 (Panx1) is fairly ubiquitous and Pannexin3 (Panx3) is found in skin and connective tissue, both are fully glycosylated, traffic to the plasma membrane and have functions correlated with extracellular ATP release. Here, we describe trafficking and subcellular localizations of exogenous Panx2 and Panx1 protein expression in MDCK, HeLa, and HEK 293T cells as well as endogenous Panx1 and Panx2 patterns in the CNS. Panx2 was found in intracellular localizations, was partially N-glycosylated, and localizations were non-overlapping with Panx1. Confocal images of hippocampal sections immunolabeled for the astrocytic protein GFAP, Panx1 and Panx2 demonstrated that the two isoforms, Panx1 and Panx2, localized at different subcellular compartments in both astrocytes and neurons. Using recombinant fusions of Panx2 with appended genetic tags developed for correlated light and electron microscopy and then expressed in different cell lines, we determined that Panx2 is localized in the membrane of intracellular vesicles and not in the endoplasmic reticulum as initially indicated by calnexin colocalization experiments. Dual immunofluorescence imaging with protein markers for specific vesicle compartments showed that Panx2 vesicles are early endosomal in origin. In electron tomographic volumes, cross-sections of these vesicles displayed fine structural details and close proximity to actin filaments. Thus, pannexins expressed at different subcellular compartments likely exert distinct functional roles, particularly in the nervous system. © 2015 Boassa, Nguyen, Hu, Ellisman and Sosinsky.
Lavine B.K.,Oklahoma State University |
Nuguru K.,Oklahoma State University |
Mirjankar N.,Oklahoma State University |
Workman J.,Unity Scientific LLC |
Workman J.,National University of La Jolla
Microchemical Journal | Year: 2012
435 infrared (IR) absorbance spectra of 140 carboxylic acids and 295 noncarboxylic acids which included aldehydes, ketones, esters, amides as well as compounds containing both carbonyls and alcohols were preprocessed using the wavelet packet tree to enhance subtle but important features in the data. Wavelet coefficients that optimized the separation of the spectra by functional group in a plot of the two largest principal components of the data were identified using a genetic algorithm (GA) for pattern recognition analysis. Because principal components maximize variance, the bulk of the information encoded by the wavelet coefficients selected by the pattern recognition GA is characteristic of the carboxylic acid functional group. The carboxylic acid search prefilter developed as part of this study was successfully validated using two external validation sets. The first validation set consisted of 24 carboxylic acids and 61 noncarboxylic acids and the second validation set consisted of 264 carboxylic acids and 72 noncarboxylic acids. © 2012 Elsevier B.V..
Prokop P.,University of Trnava |
Prokop P.,Slovak Academy of Sciences |
Maxwell M.R.,National University of La Jolla
Animal Behaviour | Year: 2012
Males of the spider Pisaura mirabilis offer prey items as nuptial gifts to females. While gift giving in this species has received attention in captivity, the ecological context of these gifts remains largely unknown. First, we examine the occurrence of gift carrying by males in nature. Field data reveal that gift-carrying males are frequent in nature (40% of captured males), and that all gifts contain fresh arthropod prey. Gift mass was positively correlated with the longest diameter of the gift. Thus, males do not appear to 'cheat' by inflating their gifts with inedible items, air or loosely wrapped silk. Second, we examine two ecological costs to gift-carrying males: the effects of gifts on male running speed and male fighting success. Gift carrying reduced male running speed, but did not affect male fighting success in male-male contests. The former result is the first demonstration of a transportation cost associated with gift carrying in an arthropod. © 2012 The Association for the Study of Animal Behaviour.
Maxwell M.R.,National University of La Jolla
Zootaxa | Year: 2014
Stagmomantis is a remarkable genus within the Mantodea, being relatively species-rich and geographically widespread. Yet, the number of species within the genus remains curiously unresolved. The present synoptic review surveys the literature on Stagmomantis to identify named species for which scientific consensus exists, as well as to summarize basic biological information for each species, including geographic distribution, morphological features, and sex-specific biometric data. The review identifies 23 consensus taxa within Stagmomantis: 22 separate species, with one of these species, S. montana, split into two subspecies (S. m. montana and S. m. sinaloae). The review indicates morphological features that may prove to be diagnostic for a given species, particularly when examined in conjunction with male genitalia. Such features include dark spots on the anterior femur (S. amazonica, S. centralis, S. marginata, S. nahua, S. venusta, S. vicina), spines or denticulations on the anterior coxa (S. colorata, S. montana montana, S. parvidentata, S. theophila), and dark bands on abdominal tergites (S. californica, S. colorata, S. domingensis). Color variation of certain features with respect to body coloration, such as stigma coloration and body and leg markings, requires more attention. Information on life history, reproduction, and ecology are summarized, particularly for temperate populations of S. carolina and S. limbata. While the 23 consensus taxa represent a robust appraisal of the existing literature, some taxonomic uncertainties remain. The status of two species are somewhat unclear (S. marginata and S. tolteca), calling for taxonomic evaluation. Furthermore, proposed within-genus groupings deserve examination, as do possible subdivisions within some species (e.g., S. limbata, S. parvidentata). Information on basic morphology and biometry remains incomplete for nearly all species. Extreme examples are S. amazonica, S. costalis, and S. paraensis, for which females have not been described. Live animal research on life history, behavior, and ecology is needed for all species, with the possible exceptions of S. carolina and S. limbata. By reconciling species assignments and consolidating biological information for the 23 consensus taxa, this synoptic review promises to guide subsequent systematic and phylogenetic investigations of the genus Stagmomantis.
Maxwell M.R.,National University of La Jolla |
Gallego K.M.,National University of La Jolla |
Barry K.L.,Macquarie University
Ecological Entomology | Year: 2010
Female feeding regime exhibited a cascade of effects on reproductive biology and behaviour in the mantid Stagmomantis limbata (Hahn).Well-fed females (High diet) consistently attained greater body mass, thicker abdomens, and higher fecundity than food-limited females (Low diet) in four annual generations. Dorso-ventral abdominal thickness strongly correlated with fecundity.In an experiment in captivity, Low diet females were more likely to cannibalize males than High diet females.High diet females attracted more males than Low diet females in several contexts. In terms of long-range attraction, caged High diet females attracted more males in the field. In terms of short-range attraction, males preferentially mounted and copulated with High diet females in captive paired choice trials. In naturally-occurring pairs in the field, a preference for females with thick abdomens was evident. These results point to two possible explanations: male choice for well-fed females and state-dependent female pheromone emission.Two years of field data indicate considerable variation in female feeding success, as measured by abdominal thickness. Average feeding success in nature appears to be relatively high, when comparing the rate of abdominal expansion in the field to captive females maintained on High diets.In the field, nearly all mounts and copulations occurred in September in both years, when female feeding success is expected to be high. If mating activity occurs during a window of high female feeding success, so as to reduce the risk of cannibalism for males, then the female feeding regime may be implicated in the phenology of mating activity in cannibalistic species. © 2010 The Authors. Ecological Entomology © 2010 The Royal Entomological Society.
Lee M.,Chonbuk National University |
Gatton T.M.,National University of La Jolla
Sensors | Year: 2010
Ubiquitous home healthcare systems have been playing an increasingly significant role in the treatment and management of chronic diseases, such as diabetes and hypertension, but progress has been hampered by the lack of standardization in the exchange of medical health care information. In an effort to establish standardization, this paper proposes a home healthcare monitoring system data exchange scheme between the HL7 standard and the IEEE1451 standard. IEEE1451 is a standard for special sensor networks, such as industrial control and smart homes, and defines a suite of interfaces that communicate among heterogeneous networks. HL7 is the standard for medical information exchange among medical organizations and medical personnel. While it provides a flexible data exchange in health care domains, it does not provide for data exchange with sensors. Thus, it is necessary to develop a data exchange schema to convert data between the HL7 and the IEEE1451 standard. This paper proposes a schema that can exchange data between HL7 devices and the monitoring device, and conforms to the IEEE 1451 standard. The experimental results and conclusions of this approach are presented and show the feasibility of the proposed exchange schema. © 2010 by the authors.
Serdyukov P.,National University of La Jolla
Journal of Computing and Information Technology | Year: 2015
The extensive integration of information technologies in teaching and learning in the 21st century has initiated a dramatic change of educational paradigm. To a large extent this change was caused by the online education. A rapid growth of online university programs raises a number of new pedagogical, psychological and social issues. Online learning creates a learning environment that, compared to traditional, classroom-based education, is less personal, more independent, often fragmented, rarely systemic, distributed in space and time, and dependent on the learner rather than on the teacher. Many problems with online education (high attrition rate, orientation at highly skilled and highly motivated people, among other issues (The Trouble with Online College, 2013), indicate that one of its major challenges is not the technology itself or its classroom applications, but the lack of sound, research-based theoretical framework as the foundation of quality online learning. A comprehensive and effective educational theory is thus crucial for the quality education. This article makes an argument for such a theory and offers a model of online pedagogy for higher education with a focus on instruction and instructor, student autonomy, socialization through networking and collaboration in the online learning environment.
Lo A.,National United University |
Cruz A.P.,National University of La Jolla
20th Americas Conference on Information Systems, AMCIS 2014 | Year: 2014
This research analyzes the undergraduate Information Systems (IS) degree programs offered by the 24 most heavily-recruited universities in the U.S. We compared the published program learning outcomes of these IS programs against the AIS/ACM IS 2010 higher-level IS capabilities as well as IS specific knowledge and skills. We also compared the track designs of these programs against the IS 2010 career tracks. Our conclusion is that, IS 2010 has not been explicitly followed by these programs.
Lee M.,Chonbuk National University |
Cho N.-D.,Chung - Ang University |
Gatton T.M.,National University of La Jolla
Information Sciences | Year: 2010
User authority delegation is granting or withdrawing access to computer-based information by entities that own and/or control that information. These entities must consider who should be granted access to specific information in the organization and determine reasonable authority delegation. Role Based Access Control (RBAC) delegation management, where user access authority is granted for the minimum resources necessary for users to perform their tasks, is not suitable for the actual working environment of an organization. Currently, RBAC implementations cannot correctly model inheritance and rules for different delegations are in conflict. Further, these systems require that user roles, positions, and information access be continuously and accurately updated, resulting in a manual, error-prone access delegation system. This paper presents a proposal for a new authority delegation model, which allows users to identify their own function-based delegation requirements as the initial input to the RBAC process. The conditions for delegations are identified and functions to implement these delegations are defined. The criteria for basic authority delegation, authentication and constraints are quantified and formulated for evaluation. An analysis of the proposed model is presented showing that this approach both minimizes errors in delegating authority and is more suitable for authority delegation administration in real organizational applications. © 2009 Elsevier Inc. All rights reserved.
Abookasis D.,Ariel University |
Workman J.J.,Biotechnology Business Associates |
Workman J.J.,Liberty University |
Workman J.J.,National University of La Jolla
Chemometrics and Intelligent Laboratory Systems | Year: 2011
In this study, a simple screening algorithm was developed to prevent the occurrence of Type II errors or samples with high prediction error that are not detected as outliers. The method is used to determine "good" and "bad" spectra and to prevent a false negative condition where poorly predicted samples appear to be within the calibration space, yet have inordinately large residual or prediction errors. The detection and elimination of this type of sample, which is a true outlier but not easily detected, is extremely important in medical decisions, since such erroneous data can lead to considerable mistakes in clinical analysis and medical diagnosis. The algorithm is based on a cross-correlation comparison between samples spectra measured over the region of 4160-4880cm-1. The correlation values are converted using the Fisher's z-transform, while a z-test of the transformed values is performed to screen out the outlier spectra. This approach allows the use of a tuning parameter used to decrease the percentage of samples with high analytical (residual) errors. The algorithm was tested using a dataset with known reference values to determine the number of false negative and false positive samples. The cross-correlation algorithm performance was tested on several hundred blood samples prepared at different hematocrit (24 to 48%) and glucose (30 to 500mg/dL) levels using blood component materials from thirteen healthy human volunteers. Experimental results illustrate the effectiveness of the proposed algorithm in finding and screening out Type II outliers in terms of sensitivity and specificity, and the ability to predict or estimate future or validation datasets ensuring lower error of prediction. To our knowledge this is the first paper to introduce a statistically useful screening method based on spectra cross-correlation to detect the occurrence of Type II outliers (false negative samples) for routine analysis in a clinically relevant application for medical diagnosis. © 2011 Elsevier B.V.