RESUMO
Non-structural carbohydrates (NSC) are major substrates for plant metabolism and have been implicated in mediating drought-induced tree mortality. Despite their significance, NSC dynamics in tropical forests remain little studied. We present leaf and branch NSC data for 82 Amazon canopy tree species in six sites spanning a broad precipitation gradient. During the wet season, total NSC (NSCT) concentrations in both organs were remarkably similar across communities. However, NSCT and its soluble sugar (SS) and starch components varied much more across sites during the dry season. Notably, the proportion of leaf NSCT in the form of SS (SS:NSCT) increased greatly in the dry season in almost all species in the driest sites, implying an important role of SS in mediating water stress in these sites. This adjustment of leaf NSC balance was not observed in tree species less-adapted to water deficit, even under exceptionally dry conditions. Thus, leaf carbon metabolism may help to explain floristic sorting across water availability gradients in Amazonia and enable better prediction of forest responses to future climate change.
Assuntos
Carboidratos/análise , Secas , Florestas , Estações do Ano , Árvores/metabolismo , Água/metabolismo , Bolívia , Brasil , Metabolismo dos Carboidratos , Mudança Climática , Geografia , Peru , Folhas de Planta/metabolismo , Açúcares/metabolismo , Árvores/classificação , Clima TropicalRESUMO
Las poblaciones a nivel mundial envejecen a un ritmo acelerado, en El Salvador las personas mayores de 65 años en los últimos 70 años han representado un aumento del 2.9% al 6.8% según el último censo de población y vivienda 2007. Según la Dirección general de estadísticas y censos en estimaciones y proyecciones para el 2050 el envejecimiento poblacional aumenta hasta un 15.6%. La importancia de una población envejecida data en la existencia de fragilidad, existe evidencia de que la fragilidad puede convertirse en uno de los problemas de salud más graves del mundo. Con el número de personas mayores expandiéndose dramáticamente en todos los países, se espera que la prevalencia de fragilidad aumente. En nuestros centros de atención primaria del sistema público no se realiza ningún cribado de identificación pese a su importancia. Por esta razón se planteó el estudio en atención primaria, que abarca cuatro comunidades de la ciudad de San Salvador y que mediante la herramienta Test de cribado de fragilidad de Gerontopole (GFST) se obtiene 34.4% de adultos mayores con fragilidad que requiere una evaluación y tratamiento integral en centros de atención de jerarquía mayor.
Assuntos
Idoso Fragilizado , Medicina de Família e ComunidadeRESUMO
Nanomaterials are the subject of intense research, focused on their synthesis, modification, and biomedical applications. Increased nanomaterial production and their wide range of applications imply a higher risk of human and environmental exposure. Unfortunately, neither environmental effects nor toxicity of nanomaterials to organisms are fully understood. Cost-effective, rapid toxicity assays requiring minimal amounts of materials are needed to establish both their biomedical potential and environmental safety standards. Drosophila exemplifies an efficient and cost-effective model organism with a vast repertoire of in vivo tools and techniques, all with high-throughput scalability and screening feasibility throughout its life cycle. Here we report tissue specific nanomaterial assessment through direct microtransfer into target tissues. We tested several nanomaterials with potential biomedical applications such as single-wall carbon nanotubes, multiwall carbon nanotubes, silver, gold, titanium dioxide, and iron oxide nanoparticles. Assessment of nanomaterial toxicity was conducted by evaluating progression through developmental morphological milestones in Drosophila. This cost-effective assessment method is amenable to high-throughput screening.
Assuntos
Bioensaio/instrumentação , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/embriologia , Microinjeções/instrumentação , Micromanipulação/instrumentação , Nanopartículas/toxicidade , Testes de Toxicidade/instrumentação , Animais , Drosophila melanogaster/fisiologia , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/fisiologia , Desenho de Equipamento , Análise de Falha de Equipamento , Nanopartículas/administração & dosagemRESUMO
Today, more minority students are entering undergraduate programs than ever before, but they earn only 6% of all science or engineering PhDs awarded in the United States. Many studies suggest that hands-on research activities enhance students' interest in pursuing a research career. In this paper, we present a model for the implementation of laboratory research in the undergraduate teaching laboratory using a culturally relevant approach to engage students. Laboratory modules were implemented in upper-division genetics and cell biology courses using cassava as the central theme. Students were asked to bring cassava samples from their respective towns, which allowed them to compare their field-collected samples against known lineages from agricultural stations at the end of the implementation. Assessment of content and learning perceptions revealed that our novel approach allowed students to learn while engaged in characterizing Puerto Rican cassava. In two semesters, based on the percentage of students who answered correctly in the premodule assessment for content knowledge, there was an overall improvement of 66% and 55% at the end in the genetics course and 24% and 15% in the cell biology course. Our proposed pedagogical model enhances students' professional competitiveness by providing students with valuable research skills as they work on a problem to which they can relate.