Yale University

About: Yale University is a education organization based out in New Haven, Connecticut, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 89824 authors who have published 220665 publications receiving 12834776 citations. The organization is also known as: Yale & Collegiate School.

X-tile: a new bio-informatics tool for biomarker assessment and outcome-based cut-point optimization

Abstract: The ability to parse tumors into subsets based on biomarker expression has many clinical applications; however, there is no global way to visualize the best cut-points for creating such divisions. We have developed a graphical method, the X-tile plot that illustrates the presence of substantial tumor subpopulations and shows the robustness of the relationship between a biomarker and outcome by construction of a two dimensional projection of every possible subpopulation. We validate X-tile plots by examining the expression of several established prognostic markers (human epidermal growth factor receptor-2, estrogen receptor, p53 expression, patient age, tumor size, and node number) in cohorts of breast cancer patients and show how X-tile plots of each marker predict population subsets rooted in the known biology of their expression.

Do Institutions Cause Growth

Abstract: We revisit the debate over whether political institutions cause economic growth, or whether, alternatively, growth and human capital accumulation lead to institutional improvement. We find that most indicators of institutional quality used to establish the proposition that institutions cause growth are constructed to be conceptually unsuitable for that purpose. We also find that some of the instrumental variable techniques used in the literature are flawed. Basic OLS results, as well as a variety of additional evidence, suggest that (a) human capital is a more basic source of growth than are the institutions, (b) poor countries get out of poverty through good policies, often pursued by dictators, and (c) subsequently improve their political institutions.

Conservation of the sequence and temporal expression of let-7 heterochronic regulatory RNA

Abstract: Two small RNAs regulate the timing of Caenorhabditis elegans development. Transition from the first to the second larval stage fates requires the 22-nucleotide lin-4 RNA and transition from late larval to adult cell fates requires the 21-nucleotide let-7 RNA. The lin-4 and let-7 RNA genes are not homologous to each other, but are each complementary to sequences in the 3' untranslated regions of a set of protein-coding target genes that are normally negatively regulated by the RNAs. Here we have detected let-7 RNAs of ~21 nucleotides in samples from a wide range of animal species, including vertebrate, ascidian, hemichordate, mollusc, annelid and arthropod, but not in RNAs from several cnidarian and poriferan species, Saccharomyces cerevisiae, Escherichia coli or Arabidopsis. We did not detect lin-4 RNA in these species. We found that let-7 temporal regulation is also conserved: let-7 RNA expression is first detected at late larval stages in C. elegans and Drosophila , at 48 hours after fertilization in zebrafish, and in adult stages of annelids and molluscs. The let-7 regulatory RNA may control late temporal transitions during development across animal phylogeny.

Phosphoinositides in cell regulation and membrane dynamics

Abstract: Inositol phospholipids have long been known to have an important regulatory role in cell physiology. The repertoire of cellular processes known to be directly or indirectly controlled by this class of lipids has now dramatically expanded. Through interactions mediated by their headgroups, which can be reversibly phosphorylated to generate seven species, phosphoinositides play a fundamental part in controlling membrane-cytosol interfaces. These lipids mediate acute responses, but also act as constitutive signals that help define organelle identity. Their functions, besides classical signal transduction at the cell surface, include regulation of membrane traffic, the cytoskeleton, nuclear events and the permeability and transport functions of membranes.