Mississippi State University

About: Mississippi State University is a education organization based out in Starkville, Mississippi, United States. It is known for research contribution in the topics: Population & Catfish. The organization has 14115 authors who have published 28594 publications receiving 700030 citations. The organization is also known as: The Mississippi State University of Agriculture and Applied Science & Mississippi State University of Agriculture and Applied Science.

A computational framework for influenza antigenic cartography.

Abstract: Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI) assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses) and reference antisera (antibodies). Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS). In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses), we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap.

Purposes for Doing Homework Reported by Middle and High School Students

Abstract: The author examined purposes for doing homework perceived by 920 students in Grades 5-12. Through an exploratory factor analysis, 8 homework purposes were reduced to 2 factor structures: Intrinsic Reasons and Extrinsic Reasons, Both factors related positively to students' use of homework management strategies. However, only Intrinsic Reasons was related to lower frequency of incomplete homework and to higher self-reported grade. Each factor was further subjected to a 2 x 2 x 2 (Grade x Gender x Homework Help) analysis of variance. Older students and students who did not receive homework help were more likely to disagree that they did homework for extrinisc reasons. The effect of homework help on Intrinsic Reasons was apparent among only the boys.

The Determinants of REIT Cash Holdings

Abstract: The factors influencing the cash holdings of REITs are examined with the view that the REIT industry should yield new information regarding the drivers of corporate cash policy due to their unique operating conditions. The availability of REIT line of credit data also allows us to test the association between cash holdings and line of credit access and use. Data constraints in prior investigations have left this an unresolved empirical question in the cash holdings literature. The baseline results show that REIT cash holdings are inversely related to funds from operations, leverage, and internal advisement and are directly related to the cost of external finance and growth opportunities. Cash holdings are also negatively associated with credit line access and use. The results imply that REIT managers elect to hold little cash to reduce the agency problems of cash flow thereby increasing transparency and reducing the future cost of external capital.

Phylogenomics demonstrates that breviate flagellates are related to opisthokonts and apusomonads.

Abstract: Most eukaryotic lineages belong to one of a few major groups. However, several protistan lineages have not yet been robustly placed in any of these groups. Both the breviates and apusomonads are two such lineages that appear to be related to the Amoebozoa and Opisthokonta (i.e. the ‘unikonts’ or Amorphea); however, their precise phylogenetic positions remain unclear. Here, we describe a novel microaerophilic breviate, Pygsuia biforma gen. nov. sp. nov., isolated from a hypoxic estuarine sediment. Ultrastructurally, this species resembles the breviate genera Breviata and Subulatomonas but has two cell morphologies, adherent and swimming. Phylogenetic analyses of the small sub-unit rRNA gene show that Pygsuia is the sister to the other breviates. We constructed a 159-protein supermatrix, including orthologues identified in RNA-seq data from Pygsuia. Phylogenomic analyses of this dataset show that breviates, apusomonads and Opisthokonta form a strongly supported major eukaryotic grouping we name the Obazoa. Although some phylogenetic methods disagree, the balance of evidence suggests that the breviate lineage forms the deepest branch within Obazoa. We also found transcripts encoding a nearly complete integrin adhesome from Pygsuia, indicating that this protein complex involved in metazoan multicellularity may have evolved earlier in eukaryote evolution than previously thought.