http://biblioteca.universia.net/verColeccion.do?id=4003 Mostrando recursos 1 - 20 de 184,040 es http://biblioteca.universia.net/img/logotipo.jpg http://biblioteca.universia.net/ http://biblioteca.universia.net/ficha.do?id=5039820 Tomato spotted wilt virus (TSWV) is transmitted exclusively by thrips in nature. A reassortment-based viral genetic system was used to map transmissibility by thrips to the medium (M) RNA of TSWV. To locate determinants of thrips transmission in the M RNA, 30 single-lesion isolates (SLIs) were generated from a single TSWV isolate that was inefficiently transmitted by thrips. Three of the 30 SLIs were transmitted by thrips, and 27 were not. Sequence analysis of the M RNA, thrips transmissibili... Sin, Sang-Hoon; McNulty, Brian C.; Kennedy, George G.; Moyer, James W. http://biblioteca.universia.net/ficha.do?id=5039821 Worldwide HIV-1 vaccine efforts are guided by the principle that HIV-specific T cell responses may provide protection from infection or delay overt disease. However, no clear correlates of T cell-mediated immune protection have been identified. Here, we examine in a HLA-B27+ HIV seronegative vaccinee persistent HIV-specific vaccine-induced anti-Gag CD4+ and CD8+ T cell responses. Although these responses exhibited those characteristics (multifunctionality, appropriate memory phenotype, and ta... Betts, Michael R.; Exley, Barbara; Price, David A.; Bansal, Anju; Camacho, Zenaido Tres; Teaberry, Vanessa; West, Sadie M.; Ambrozak, David R.; Tomaras, Georgia; Roederer, Mario; Kilby, J. Michael; Tartaglia, Jim; Belshe, Robert; Gao, Feng; Douek, Daniel C.; Weinhold, Kent J.; Koup, Richard A.; Goepfert, Paul; Ferrari, Guido http://biblioteca.universia.net/ficha.do?id=5039822 The protooncogene MYC has been implicated in both the proliferation and programmed cell death of lymphoid cells, and in the genesis of lymphoid tumors. Here, we report that overexpression of MYC, as found in many lymphomas, can break immune tolerance. Mice that would otherwise be tolerant to a transgenic autoantigen mounted an immune response to the antigen if MYC was vigorously expressed in the B cell lineage. The responsive B cells converted to an activated phenotype and produced copious am... Refaeli, Yosef; Field, Kenneth A.; Turner, Brian C.; Trumpp, Andreas; Bishop, J. Michael http://biblioteca.universia.net/ficha.do?id=5039823 In this article we use laboratory experiments to ask a fundamental question: Do individuals behave as if their risk preferences are stable across institutions? In particular, we study the decisions of cash-motivated subjects in the repeated play of three different institutions: a value elicitation procedure for the sale of a risky asset, an English clock auction for the sale of a risky asset, and a first-price auction for the purchase of a riskless asset. We first do a simple categorical comp... Berg, Joyce; Dickhaut, John; McCabe, Kevin http://biblioteca.universia.net/ficha.do?id=5039824 The production of mature germ cells capable of generating totipotent zygotes is a highly specialized and sexually dimorphic process. The transition from diploid primordial germ cell to haploid spermatozoa requires genome-wide reprogramming of DNA methylation, stage- and testis-specific gene expression, mitotic and meiotic division, and the histone–protamine transition, all requiring unique epigenetic control. Dnmt3L, a DNA methyltransferase regulator, is expressed during gametogenesis, and it... Webster, Kylie E.; O'Bryan, Moira K.; Fletcher, Stephen; Crewther, Pauline E.; Aapola, Ulla; Craig, Jeff; Harrison, Dion K.; Aung, Hnin; Phutikanit, Nawapen; Lyle, Robert; Meachem, Sarah J.; Antonarakis, Stylianos E.; de Kretser, David M.; Hedger, Mark P.; Peterson, Pärt; Carroll, Bernard J.; Scott, Hamish S. http://biblioteca.universia.net/ficha.do?id=5039825 Unfertilized vertebrate eggs are arrested in metaphase of meiosis II with high cyclin B/Cdc2 activity to prevent parthenogenesis. Until fertilization, exit from metaphase is blocked by an activity called cytostatic factor (CSF), which stabilizes cyclin B by inhibiting the anaphase-promoting complex (APC) ubiquitin ligase. The APC inhibitor early mitotic inhibitor 1 (Emi1) was recently found to be required for maintenance of CSF arrest. We show here that exogenous Emi1 is unstable in CSF-arres... Tung, Jeffrey J.; Hansen, David V.; Ban, Kenneth H.; Loktev, Alexander V.; Summers, Matthew K.; Adler, John R.; Jackson, Peter K. http://biblioteca.universia.net/ficha.do?id=5039826 Over 15% of the data sets catalogued in the Gene Expression Omnibus Database involve RNA samples that have been pooled before hybridization. Pooling affects data quality and inference, but the exact effects are not yet known because pooling has not been systematically studied in the context of microarray experiments. Here we report on the results of an experiment designed to evaluate the utility of pooling and the impact on identifying differentially expressed genes. We find that inference fo... Kendziorski, C.; Irizarry, R. A.; Chen, K.-S.; Haag, J. D.; Gould, M. N. http://biblioteca.universia.net/ficha.do?id=5039827 Triplication of whole autosomes or large autosomal segments is detrimental to the development of a mammalian embryo. The trisomy of human chromosome (Chr) 21, known as Down's syndrome, is regularly associated with mental retardation and a variable set of other developmental anomalies. Several mouse models of Down's syndrome, triplicating 33–104 genes of Chr16, were designed in an attempt to analyze the contribution of specific orthologous genes to particular developmental features. However, a... Vacík, Tomáš; Ort, Michael; Gregorová, So?a; Strnad, Petr; Blatný, Radek; Conte, Nathalie; Bradley, Allan; Bureš, Jan; Forejt, Ji?í http://biblioteca.universia.net/ficha.do?id=5040086 We present a technique for the directed assembly and self-assembly of micrometer-scale structures based on the control of specific DNA linkages between colloidal particles. The use of DNA links combined with polymer brushes provides an effective way to regulate the range and magnitude of addressable forces between pairs (and further combinations) of different particles. We demonstrate that the autoassembly of alternate microbeads as well as their directed assembly, by using laser tweezers, is... Valignat, Marie-Pierre; Theodoly, Olivier; Crocker, John C.; Russel, William B.; Chaikin, Paul M. http://biblioteca.universia.net/ficha.do?id=5040087 A method to genetically program mouse hematopoietic stem cells to develop into functional CD8 or CD4 T cells of defined specificity in vivo is described. For this purpose, a bicistronic retroviral vector was engineered that efficiently delivers genes for both ? and ? chains of T cell receptor (TCR) to hematopoietic stem cells. When modified cell populations were used to reconstruct the hematopoietic lineages of recipient mice, significant percentages of antigen-specific CD8 or CD4 T cells wer... Yang, Lili; Baltimore, David http://biblioteca.universia.net/ficha.do?id=5040749 We used airborne imaging spectroscopy and photon transport modeling to determine how biological invasion altered the chemistry of forest canopies across a Hawaiian montane rain forest landscape. The nitrogen-fixing tree Myrica faya doubled canopy nitrogen concentrations and water content as it replaced native forest, whereas the understory herb Hedychium gardnerianum reduced nitrogen concentrations in the forest overstory and substantially increased aboveground water content. This remote sens... Asner, Gregory P.; Vitousek, Peter M. http://biblioteca.universia.net/ficha.do?id=5040750 Eukaryotes have evolved elaborate splicing mechanisms to remove introns that would otherwise destroy the protein-coding capacity of genes. Nuclear premRNA splicing requires sequence motifs in the intron and is mediated by a ribonucleoprotein complex, the spliceosome. Here we demonstrate the presence of a splicing apparatus in the protist Trichomonas vaginalis and show that RNA motifs found in yeast and metazoan introns are required for splicing. We also describe the first introns in this deep... Va?á?ová, Št?pánka; Yan, Weihong; Carlton, Jane M.; Johnson, Patricia J. http://biblioteca.universia.net/ficha.do?id=5041441 Safe, effective, orally delivered, live adenovirus vaccines have been in use for three decades. Recombinant derivatives of the live adenovirus vaccines may prove an economical alternative to current vaccines for a variety of diseases. To explore that possibility, we constructed a series of recombinants that express the major capsid protein (L1) of canine oral papillomavirus (COPV), a model for mucosal human papillomavirus (HPV) infection. Vaccination with virus-like particles (VLPs) composed ... Berg, Michael; DiFatta, Julie; Hoiczyk, Egbert; Schlegel, Richard; Ketner, Gary http://biblioteca.universia.net/ficha.do?id=5041442 Early-stage mammalian embryos develop in a low O2 environment (hypoxia). hES cells, however, are generally cultured under an atmosphere of 21% O2 (normoxia), under which conditions they tend to differentiate spontaneously. Such conditions may not be the most suitable, therefore, for hES cell propagation. Here we have tested two hypotheses. The first hypothesis was that hES cells would grow as well under hypoxic as under normoxic conditions. The second hypothesis was that hypoxic culture would... Ezashi, Toshihiko; Das, Padmalaya; Roberts, R. Michael http://biblioteca.universia.net/ficha.do?id=5041533 KLF11 (TIEG2) is a pancreas-enriched transcription factor that has elicited significant attention because of its role as negative regulator of exocrine cell growth in vitro and in vivo. However, its functional role in the endocrine pancreas remains to be established. Here, we report, for the first time, to our knowledge, the characterization of KLF11 as a glucose-inducible regulator of the insulin gene. A combination of random oligonucleotide binding, EMSA, luciferase reporter, and chromatin ... Neve, Bernadette; Fernandez-Zapico, Martin E.; Ashkenazi-Katalan, Vered; Dina, Christian; Hamid, Yasmin H.; Joly, Erik; Vaillant, Emmanuel; Benmezroua, Yamina; Durand, Emmanuelle; Bakaher, Nicolas; Delannoy, Valerie; Vaxillaire, Martine; Cook, Tiffany; Dallinga-Thie, Geesje M.; Jansen, Hans; Charles, Marie-Aline; Clément, Karine; Galan, Pilar; Hercberg, Serge; Helbecque, Nicole; Charpentier, Guillaume; Prentki, Marc; Hansen, Torben; Pedersen, Oluf; Urrutia, Raul; Melloul, Danielle; Froguel, Philippe http://biblioteca.universia.net/ficha.do?id=5041534 In voltage-dependent channels, positive charges contained within the S4 domain are the voltage-sensing elements. The “voltage-sensor paddle” gating mechanism proposed for the KvAP K+ channel has been the subject of intense discussion regarding its general applicability to the family of voltage-gated channels. In this model, the voltage sensor composed of the S3b and the S4 segment shuttles across the lipid bilayer during channel activation. Guided by this mechanism, we assessed here the acces... Gonzalez, Carlos; Morera, Francisco J.; Rosenmann, Eduardo; Alvarez, Osvaldo; Latorre, Ramon http://biblioteca.universia.net/ficha.do?id=5041689 The application of genome-wide expression analysis to a large-scale, multicentered program in critically ill patients poses a number of theoretical and technical challenges. We describe here an analytical and organizational approach to a systematic evaluation of the variance associated with genome-wide expression analysis specifically tailored to study human disease. We analyzed sources of variance in genome-wide expression analyses performed with commercial oligonucleotide arrays. In additio... Cobb, J. Perren; Mindrinos, Michael N.; Miller-Graziano, Carol; Calvano, Steve E.; Baker, Henry V.; Xiao, Wenzhong; Laudanski, Krzysztof; Brownstein, Bernard H.; Elson, Constance M.; Hayden, Douglas L.; Herndon, David N.; Lowry, Stephen F.; Maier, Ronald V.; Schoenfeld, David A.; Moldawer, Lyle L.; Davis, Ronald W.; Tompkins, Ronald G.; http://biblioteca.universia.net/ficha.do?id=5041690 We examined whether the performance of the National Institute of Aging's Consortium to Establish a Registry for Alzheimer's Disease's 10-word list (CWL), part of the consortium's neuropsychological battery, can be improved for detecting Alzheimer's disease and related disorders early. We focused on mild cognitive impairment (MCI) and mild dementia because these stages often go undetected, and their detection is important for treatment. Using standardized diagnostic criteria combined with hist... Shankle, William R.; Romney, A. Kimball; Hara, Junko; Fortier, Dennis; Dick, Malcolm B.; Chen, James M.; Chan, Timothy; Sun, Xijiang http://biblioteca.universia.net/ficha.do?id=5041691 Motor neurons (MNs) are the principal neurons in the mammalian spinal cord whose activities cause muscles to contract. In addition to their peripheral axons, MNs have central collaterals that contact inhibitory Renshaw cells and other MNs. Since its original discovery >60 years ago, it has been a general notion that acetylcholine is the only transmitter released from MN synapses both peripherally and centrally. Here, we show, using a multidisciplinary approach, that mammalian spinal MNs, in a... Nishimaru, Hiroshi; Restrepo, Carlos Ernesto; Ryge, Jesper; Yanagawa, Yuchio; Kiehn, Ole http://biblioteca.universia.net/ficha.do?id=5041692 Canavan's disease (CD) is a fatal, hereditary disorder of CNS development that has been linked to mutations in the gene for the enzyme aspartoacylase (ASPA) (EC 3.5.1.15). ASPA acts to hydrolyze N-acetylaspartate (NAA) into l-aspartate and acetate, but the connection between ASPA deficiency and the failure of proper CNS development is unclear. We hypothesize that one function of ASPA is to provide acetate for the increased lipid synthesis that occurs during postnatal CNS myelination. The gene... Madhavarao, Chikkathur N.; Arun, Peethambaran; Moffett, John R.; Szucs, Sylvia; Surendran, Sankar; Matalon, Reuben; Garbern, James; Hristova, Diana; Johnson, Anne; Jiang, Wei; Namboodiri, M. A. Aryan