Louisiana State University

About: Louisiana State University is a education organization based out in Baton Rouge, Louisiana, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 40206 authors who have published 76587 publications receiving 2566076 citations. The organization is also known as: LSU & Louisiana State University and Agricultural and Mechanical College.

Micro-RNA speciation in fetal, adult and Alzheimer's disease hippocampus.

Abstract: Micro-RNAs constitute a family of small noncoding ribonucleic acids that are posttranscriptional regulators of messenger RNA activity. Although micro-RNAs are known to be dynamically regulated during neural development, the role of micro-RNAs in brain aging and neurodegeneration is not known. This study examined micro-RNA abundance in the hippocampal region of fetal, adult and Alzheimer's disease brain. The data indicate that micro-RNAs encoding miR-9, miR-124a, miR-125b, miR-128, miR-132 and miR-219 are abundantly represented in fetal hippocampus, are differentially regulated in aged brain, and an alteration in specific micro-RNA complexity occurs in Alzheimer hippocampus. These data are consistent with the idea that altered micro-RNA-mediated processing of messenger RNA populations may contribute to atypical mRNA abundance and neural dysfunction in Alzheimer's disease brain.

MicroRNA function in cancer: oncogene or a tumor suppressor?

Abstract: MicroRNAs (miRNAs) are small noncoding, double-stranded RNA molecules that can mediate the expression of target genes with complementary sequences. About 5,300 human genes have been implicated as targets for miRNAs, making them one of the most abundant classes of regulatory genes in humans. MiRNAs recognize their target mRNAs based on sequence complementarity and act on them to cause the inhibition of protein translation by degradation of mRNA. Besides contributing to development and normal function, microRNAs have functions in various human diseases. Given the importance of miRNAs in regulating cellular differentiation and proliferation, it is not surprising that their misregulation is linked to cancer. In cancer, miRNAs function as regulatory molecules, acting as oncogenes or tumor suppressors. Amplification or overexpression of miRNAs can down-regulate tumor suppressors or other genes involved in cell differentiation, thereby contributing to tumor formation by stimulating proliferation, angiogenesis, and invasion; i.e., they act as oncogenes. Similarly, miRNAs can down-regulate different proteins with oncogenic activity; i.e., they act as tumor suppressors. This review will highlight the recent discoveries regarding miRNAs and their importance in cancer.

Source effects in communication and persuasion research: A meta-analysis of effect size

Abstract: The effect of a message source on the persuasion of a target audience has been a topic of interest to scholars in psychology, consumer behavior, and communications for many years. Narrative reviews of this literature are available; the contribution of this study is that we present a quantitative review of studies of source effects on persuasion. One of our research goals is to determine how strong and consistent source manipulations tend to be. We find that, on average, source manipulations account for nine percent of explained variance among studies reporting significant findings. In particular, expertise tends to have the greatest effect on persuasion with an average of 16 percent of the explained variance being due to the expert versus non-expert manipulation. As well as gaining insight into the pattern of results across a body of literature, our findings may be used as benchmarks by researchers, as advocated by Sawyer and Ball (1981), to evaluate results of future persuasion studies employing a source manipulation.

A Review of Accelerated Test Models

Abstract: Engineers in the manufacturing industries have used accelerated test (AT) experiments for many decades. The purpose of AT experiments is to acquire reliability information quickly. Test units of a material, component, subsystem, or entire systems are subjected to higher-than-usual levels of one or more accelerating variables such as temperature or stress. Then the AT results are used to predict life of the units at use conditions. The extrapolation is typically justified (correctly or incorrectly) on the basis of physically motivated models or a combination of empirical model fitting with a sufficient amount of previous experience in testing similar units. The need to extrapolate in both time and the accelerating variables generally necessitates the use of fully parametric models. Statisticians have made important contributions in the development of appropriate stochastic models for AT data (typically a distribution for the response and regression relationships between the parameters of this distribution and the accelerating variable(s)), statistical methods for AT planning (choice of accelerating variable levels and allocation of available test units to those levels), and methods of estimation of suitable reliability metrics. This paper provides a review of many of the AT models that have been use successfully in this area.

Characterization of sfp, a bacillus subtilis phosphopantetheinyl transferase for peptidyl carrier protein domains in peptide synthetases

Abstract: The Bacillus subtilis enzyme Sfp, required for production of the lipoheptapeptide antibiotic surfactin, posttranslationally phosphopantetheinylates a serine residue in each of the seven peptidyl carrier protein domains of the first three subunits (SrfABC) of surfactin synthetase to yield docking sites for amino acid loading and peptide bond formation. With recombinant Sfp and 16−17-kDa peptidyl carrier protein (PCP) domains excised from the SrfB1 and SrfB2 modules as apo substrates, kcat values of 56−104 min-1 and Km values of 1.3−1.8 μM were determined, indicating equivalent recognition of the adjacent PCP domains by Sfp. In contrast to other phosphopantetheinyl transferases (PPTases) previously examined, Sfp will modify the apo forms of heterologous recombinant proteins, including the PCP domain of Saccharomyces cerevisiae Lys2 (involved in lysine biosynthesis), the aryl carrier protein (ArCP) domain of Escherichia coli EntB (involved in enterobactin biosynthesis), and the E. coli acyl carrier protein (...