Time filter

Source Type

La Jolla, CA, United States

Maxwell M.R.,National University of La Jolla

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.  Source

Lee M.,Chonbuk National University | Cho N.-D.,Chung - Ang University | Gatton T.M.,National University of La Jolla
Information Sciences

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. Source

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

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. Source

Prokop P.,University of Trnava | Prokop P.,Slovak Academy of Sciences | Maxwell M.R.,National University of La Jolla
Animal Behaviour

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. Source

Serdyukov P.,National University of La Jolla
Journal of Computing and Information Technology

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. Source

Discover hidden collaborations