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Dover, DE, United States

Delaware State University , is an American historically black, public university located in Dover, Delaware. DSU also has two satellite campuses located in Wilmington, Delaware, and Georgetown, Delaware. The university encompasses six colleges and a diverse population of undergraduate and advanced-degree students. Wikipedia.

Dirichlet and transmission eigenvalues have important applications in qualitative methods in inverse scattering. Motivated by the fact that these eigenvalues can be obtained from scattering data, we propose a new eigenvalue method using multiple frequency data (EM 2F). The method detects eigenvalues and builds indicator functions to reconstruct the support of the target. Numerical reconstruction is quite satisfactory. Dirichlet or transmission eigenvalues are estimated. Furthermore, reconstruction of D and estimation of eigenvalues can be combined together to distinguish between the sound-soft obstacle and non-absorbing inhomogeneous medium. © 2012 IOP Publishing Ltd. Source

Liu L.,Delaware State University | Yu L.,Georgia Southern University
Systematic Biology

In this study, we develop a distance method for inferring unrooted species trees from a collection of unrooted gene trees. The species tree is estimated by the neighbor joining (NJ) tree built from a distance matrix in which the distance between two species is defined as the average number of internodes between two species across gene trees, that is, average gene-tree internode distance. The distance method is named NJst to distinguish it from the original NJ method. Under the coalescent model, we show that if gene trees are known or estimated correctly, the NJst method is statistically consistent in estimating unrooted species trees. The simulation results suggest that NJst and STAR (another coalescence-based method for inferring species trees) perform almost equally well in estimating topologies of species trees, whereas the Bayesian coalescence-based method, BEST, outperforms both NJst and STAR. Unlike BEST and STAR, the NJst method can take unrooted gene trees to infer species trees without using an outgroup. In addition, the NJst method can handle missing data and is thus useful in phylogenomic studies in which data sets often contain missing loci for some individuals. © 2011 The Author(s). Source

Background Misdiagnosis of African-U.S. persons is argued to be a built-in characteristic of Western-based assessment requiring augmentation with culture-focused input where possible. Regarding depression, materialistic depression is explained as an African-centered African-U.S. culture-focused construct of masked depression. Materialistic depression symptomatology is presented. Materialism orientation is postulated to necessarily be associated with materialistic depression. Method 144 undergraduates, 37 male (25.7%) and 107 female (74.3%), average age of 21 completed the Zung Self-rating Depression Scale, the depression subscale of the Symptom Checklist 90-R, the materialism subscale of the Cultural Misorientation Scale, and the Materialistic Depression Quiz. Results Contrasting high versus lower scoring MDQ groups on both depression scores produced reliable t-tests (p<.017). One-way ANOVA on materialism scores with high, medium, low MDQ groups was reliable (p<.017). Limitation The sample precluded generalization to clinically depressed and non-college African-U.S. populations. Conclusions Using the Materialistic Depression Quiz, high scorers versus medium and low scorers had greater depression scores on two depression measures and greater materialism scores. Materialistic depression appears a masked form of depression not to be overlooked. © 2013 Elsevier B.V. Source

Kingsley D.H.,Delaware State University
Food and Environmental Virology

High pressure processing (HPP) is an increasingly popular non-thermal food processing technology. Study of HPP's potential to inactivate foodborne viruses has defined general pressure levels required to inactivate hepatitis A virus, norovirus surrogates, and human norovirus itself within foods such as shellfish and produce. The sensitivity of a number of different picornaviruses to HPP is variable. Experiments suggest that HPP inactivates viruses via denaturation of capsid proteins which render the virus incapable of binding to its receptor on the surface of its host cell. Beyond the primary consideration of treatment pressure level, the effects of extending treatment times, temperature of initial pressure application, and matrix composition have been identified as critical parameters for designing HPP inactivation strategies. Research described here can serve as a preliminary guide to whether a current commercial process could be effective against HuNoV or HAV. © 2012 The Author(s). Source

Richards G.P.,Delaware State University
Food and Environmental Virology

The inability to propagate human norovirus (NoV) or to clearly differentiate infectious from noninfectious virus particles has led to the use of surrogate viruses, like feline calicivirus (FCV) and murine norovirus-1 (MNV), which are propagatable in cell culture. The use of surrogates is predicated on the assumption that they generally mimic the viruses they represent; however, studies are proving this concept invalid. In direct comparisons between FCV and MNV, their susceptibility to temperatures, environmental and food processing conditions, and disinfectants are dramatically different. Differences have also been noted between the inactivation of NoV and its surrogates, thus questioning the validity of surrogates. Considerable research funding is provided globally each year to conduct surrogate studies on NoVs; however, there is little demonstrated benefit derived from these studies in regard to the development of virus inactivation techniques or food processing strategies. Human challenge studies are needed to determine which processing techniques are effective in reducing NoVs in foods. A major obstacle to clinical trials on NoVs is the perception that such trials are too costly and risky, but in reality, there is far more cost and risk in allowing millions of unsuspecting consumers to contract NoV illness each year, when practical interventions are only a few volunteer studies away. A number of clinical trials have been conducted, providing important insights into NoV inactivation. A shift in research priorities from surrogate research to volunteer studies is essential if we are to identify realistic, practical, and scientifically valid processing approaches to improve food safety. © 2011 © The Author (outside the USA). Source

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