1,536 research outputs found

    Impaired filtering of irrelevant information in depression: an ERP study

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    Behavioural findings have led to proposals that difficulties in attention and concentration in depression may have their roots in fundamental inhibitory impairments for irrelevant information. These impairments may be associated with reduced capacity to actively maintain relevant information to facilitate goadirected behaviour. In light of mixed data from behavioural studies, the current study using direct neural measurement, examines whether dysphoric individuals show poor filtering of irrelevant information and reduced working memory (WM) capacity for relevant information. Consistent with previous research, a sustained evenrelated potential (ERP) asymmetry, termed contralateral delay activity (CDA), was observed to be sensitive to WM capacity and the efficient filtering of irrelevant information from visual WM. We found a strong positive correlation between the efficiency of filtering irrelevant items and visual WM capacity. Specifically, dysphoric participants were poor at filtering irrelevant information, and showed reduced WM capacity relative to high capacity non-dysphoric participants. Results support the hypothesis that impaired inhibition is a central feature of dysphoria and are discussed within the framework of cognitive and neurophysiological models of depression

    Transferrin-polycation-DNA complexes. The effect of polycations on the structure of the complex and DNA delivery to cells.

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    We have previously described a gene delivery system based upon the receptor-mediated endocytosis of DNA complexed with transferrin-polycation conjugates. This delivery system has been found to be very effective for both the internalization and the expression of genetic material in cells that have many transferrin receptors. Upon scrutinization of the parameters involved in this method, which we have termed transferrinfection, we note two important features of the process: the polycation in polycation-transferrin conjugates, as expected, serves to attach the transferrin moiety to the DNA and, in addition, the polycation functions to condense the DNA into a doughnut structure. Electron microscopic analysis of a range of poorly active to highly active transferrinfection samples reveals a strong correlation between DNA condensation and cellular DNA uptake. Furthermore, we demonstrate that the transfection activity of the DNA complex can be increased by addition of free polycation as long as a sufficient quantity of polycation-transferrin conjugates remains in the complex to ensure its binding to the cellular receptor

    Transferrin-polycation conjugates as carriers for DNA uptake into cells.

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    We have developed a high-efficiency nucleic acid delivery system that uses receptor-mediated endocytosis to carry DNA macromolecules into cells. We accomplished this by conjugating the iron-transport protein transferrin to polycations that bind nucleic acids. Human transferrin, as well as the chicken homologue conalbumin, has been covalently linked to the small DNA-binding protein protamine or to polylysines of various sizes through a disulfide linkage. These modified transferrin molecules maintain their ability to bind their cognate receptor and to mediate efficient iron transport into the cell. The transferrin-polycation molecules form electrophoretically stable complexes with double-stranded DNA, single-stranded DNA, and modified RNA molecules independent of nucleic acid size (from short oligonucleotides to DNA of 21 kilobase pairs). When complexes of transferrin-polycation and a bacterial plasmid DNA containing the gene for Photinus pyralis luciferase are supplied to eukaryotic cells, high-level expression of the luciferase gene occurs, demonstrating transferrin receptor-mediated endocytosis and expression of the imported DNA. We refer to this delivery system as "transferrinfection.

    Salary Distribution in the NFL

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    There are many different ways to construct an NFL lineup given a salary cap. This study looks at different salary structures to determine if there is an optimal strategy that General Managers should use when building their roster. The goal of every manager should be to have as many wins as possible in a given year. The purpose of this study is to determine if there is an optimal strategy for general managers to use to construct their lineup by looking at two main factors and their effect on the number of wins for a team: positional spending and salary inequality. Salary inequality is measured using a Lorenz Curve and a Gini Coefficient. This study used data from the Spotrac website and analyzes the 2013‐2014 season through the 2017-2018 season. By analyzing a pooled regression model, this study attempted to answer if there is a superstar effect in the NFL and determine which positions are undervalued/ overvalued. The findings indicate that certain positions have been overpaid and some underpaid over the last 5 NFL seasons. The results also show that there is no superstar effect in the NFL. This study aims to help NFL teams construct the best possible lineup for their team and win more games
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