Tropical plant species are vulnerable to climate change and global warming. Since flowering is a critical factor for plant reproduction and seed-set, warming and elevated atmospheric carbon dioxide ...concentrations (eCO2) are crucial climate change factors that can affect plant reproductive dynamics and flowering related events in the tropics. Using a combined free-air CO2 enrichment and a free-air temperature-controlled enhancement system, we investigate how warming (+2 °C above ambient, eT) and elevated CO2 (~600 ppm, eCO2) affect the phenological pattern, plant-insect interactions, and outcrossing rates in the tropical legume forage species Stylosanthes capitata Vogel (Fabaceae). In comparison to the control, a significantly greater number of flowers (NF) per plot (+62%) were observed in eT. Furthermore, in warmed plots flowers began opening approximately 1 h earlier (~09:05), with a canopy temperature of ~23 °C, than the control (~09:59) and eCO2 (~09:55) treatments. Flower closure occurred about 3 h later in eT (~11:57) and control (~13:13), with a canopy temperature of ~27 °C. These changes in flower phenology increased the availability of floral resources and attractiveness for pollinators such as Apis mellifera L. and visitors such as Paratrigona lineata L., with significant interactions between eT treatments and insect visitation per hour/day, especially between 09:00–10:40. In comparison to the control, the additive effects of combined eCO2 + eT enhanced the NF by 137%, while the number of A. mellifera floral visits per plot/week increased by 83% during the period of greatest flower production. Although we found no significant effect of treatments on mating system parameters, the overall mean multilocus outcrossing rate (tm = 0.53 ± 0.03) did confirm that S. capitata has a mixed mating system. The effects of elevated CO2 and warming on plant-pollinator relationships observed here may have important implications for seed production of tropical forage species in future climate scenarios.
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•Tropical plant species are vulnerable to climate change and global warming.•The effects of warming and elevated CO2 on tropical plant reproduction are unknown.•Warming induced early-morning flowering causing plant-visitor temporal mismatch.•Warming and elevated CO2 increase the number of flowers and pollinator visits.•Outcrossing rates are not affected by effect of warming and elevated CO2.
Acute administration of lipopolysaccharide (LPS) from Gram-negative bacteria induces hypophagia. However, the repeated administration of LPS leads to desensitization of hypophagia, which is ...associated with increased hypothalamic p-AMPK expression. Because ghrelin and endocannabinoids modulate AMPK activity in the hypothalamus, we hypothesized that these neuromodulators play a role in the reversal of tolerance to hypophagia in rats under long-term exposure to LPS. Male Wistar rats were treated with single (1 LPS, 100μg/kg body weight, ip) or repeated injections of LPS over 6days (6 LPS). Food intake was reduced in the 1 LPS, but not in the 6 LPS group. 6 LPS rats showed an increased serum concentration of acylated ghrelin and reduced ghrelin receptor mRNA expression in the hypothalamus. Ghrelin injection (40μg/kg body weight, ip) increased food intake, body weight gain, p-AMPK hypothalamic expression, neuropeptide Y (NPY) and Agouti related peptide (AgRP) mRNA expression in control animals (Saline). However, in 6 LPS rats, ghrelin did not alter these parameters. Central administration of a CB1R antagonist (AM251, 200ng/μl in 5μl/rat) induced hypophagia in 6 LPS animals, suggesting that the endocannabinoid system contributes to preserved food intake during LPS tolerance. In the presence of AM251, the ability of ghrelin to phosphorylate AMPK in the hypothalamus of 6 LPS group was restored, but not its orexigenic effect. Our data highlight that the orexigenic effects of ghrelin require CB1R signaling downstream of AMPK activation. Moreover, CB1R-mediated pathways contribute to the absence of hypophagia during repeated exposure to endotoxin.
•Prolonged exposure to endotoxin increases circulating ghrelin.•Prolonged exposure to LPS impairs the ability of exogenous ghrelin to increase food intake and p-AMPK in the hypothalamus.•CB1R antagonist restores the ability of ghrelin to phosphorylate AMPK, but not to induce feeding.•Orexigenic effects of ghrelin require CB1R signaling downstream AMPK activation.
Stylosanthes capitata Vogel and Stylosanthes macrocephala M.B.Ferreira & Sousa Costa are two forage leguminous species of agronomic importance for animal husbandry in tropical environments. The ...physical mixture of both species (80 % S. capitata and 20 % S. macrocephala) comprises the commercial cultivar “Estilosantes Campo Grande”. However, proximity of fields for seed production may contaminate seed lots, compromising seeds quality. The combined use of dominant and co-dominant molecular markers is an appropriate strategy to certificate genetic purity and perform diversity studies of cultivars. In this research, a set of ISSR (Inter-Simple Sequence Repeat polymorphic DNA) and SSR (Simple Sequence Repeat polymorphic DNA) molecular markers were standardized to characterize S. capitata and S. macrocephala species and evaluate the genetic purity of commercial samples. Four ISSR markers (UBC 2, 864, 885, 886) and SSR marker SC18-01 G4B showed precise species-specific electrophoretic fingerprints for both species. Electrophoretic patterns of ISSR molecular markers should be displayed first to confirm the sample identification. The structure analysis showed that the less contaminated sample was S. capitata with 97 % of its genetic composition assigned to a single genetic cluster vs. 95 % for S. macrocephala. S. capitata has greater genetic diversity (ISSRHe:0.292; SSRHe:0.57) than S. macrocephala (ISSRHe:0.285; SSRHe:0.16); however, this difference was only significant with SSR molecular markers. As these genetic resources have considerable ecological, agronomic and economic importance, tools for accurate species identification and genetic studies are essential for further seed multiplication, as well as for improvement and conservation of cultivars.
•Tropical plant reproductive processes are vulnerable to climate change.•Warming and eCO2 induced early degeneration of tapetum cells of pollen sacs.•Warming and eCO2 induced a less differentiated ...aperture of pollen and compaction of pollen exine.•Warming and eCO2 induced abnormalities which may hinder the viability of pollen grain.
Global climate change is expected to have impacts on the physiological, phenological, and morphological traits of plants. However, the vulnerability of tropical plant reproductive processes in response to climate change events has been poorly studied. Here, we assess if warming and elevated CO2 compromise the pollen characteristics of Stylosanthes capitata Vogel, a tropical legume forage species. This work was conducted in a Trop-T-FACE (combined Free-Air Temperature Controlled Enhancement and Free-Air Carbon Dioxide Enrichment) facility, where we exposed the plants to four treatments: C (Control-ambient atmospheric carbon dioxide concentration CO2 and ambient temperature); eCO2 (increase in CO2 to 600 ppm and ambient temperature); eT (canopy temperature increase by 2°C and ambient CO2); and eCO2+eT, a combination of both treatments. We analyzed pollen morphology of samples taken from the different treatments through light microscopy (LM) and scanning electron microscopy (SEM). In addition, pollen viability was analyzed through colorimetry. Based on the histological LM analysis, the tapetum cells of pollen sacs showed early degeneration under eT (72%) added to hypertrophy under eCO2 (67%) and eCO2+eT (90%) treatments. SEM images showed compaction of pollen exine and less distinguishable pollen apertures in the treated plots (eCO2, eT, and eCO2+eT), possibly, by the early death of the tapetum cells. These morphological abnormalities may hinder the viability of pollen grains, as observed especially in the eCO2+eT treatment (%V=64%) that was the lowest in comparison with the Control (71%) and the other treatments (eCO2 = 69%, eT = 67%). These results indicate that during the reproductive cycle of S. capitata pollen sacs and pollen grains are vulnerable to warming, elevated CO2, and their combined effects.
Avaliação da ação afirmativa no vestibular da UFBA Costa, Lilia Carolina Carneiro da; Santos, Jessica Priscila Rivas dos; Guimarães, Antonio ...
Estudos em Avaliação Educacional (Impresso),
04/2010, Letnik:
21, Številka:
45
Journal Article
Recenzirano
Odprti dostop
Com o objetivo de tornar o ensino superior acessível a todos, independentemente da classe social ou etnia, as universidades públicas vêm implantando ações afirmativas. A partir de 2005, o vestibular ...da Universidade Federal da Bahia (UFBA) possui um sistema de cotas que reserva cerca de 45% das vagas para candidatos originários de escola pública que se declaram pretos, pardos, índio-descendentes ou de outros grupos étnicos. Assim, desejando verificar as mudanças ocorridas no vestibular, em razão do sistema de cotas, este estudo utiliza dados da UFBA, de 2003 a 2008, e analisa a relação existente entre a aprovação no vestibular e as características dos candidatos, como renda familiar, cor/raça e nível educacional dos pais, entre outras variáveis. Mediante modelos logísticos ajustados a cada característica do candidato, foi observado que o sistema de cotas aumentou as chances de aprovação para os candidatos com renda familiar de 1 a 5 salários mínimos, que estudaram em escola estadual no 2º grau, e que trabalharam enquanto cursavam o ensino médio, entre outras variáveis. Já com o modelo logístico múltiplo, foi observado principalmente que a variável raça/cor apresentou uma tendência à equidade ao longo dos anos, isto é, independentemente da etnia, os candidatos tendem a ter as mesmas chances de serem aprovados no vestibular.
Este artigo tem o objetivo de trazer uma reflexão sobre a importância da avaliação emancipatória na Educação Profissional, Científica e Tecnológica (EPCT). A avaliação é uma ferramenta de julgar e ...classificar o sujeito, com base principalmente nos resultados obtidos por ele. Numa concepção mais abrangente, na Educação Profissional, a avaliação se caracteriza pelo processo de atender aos pressupostos básicos educacionais pautados na inter e transdisciplinaridade, relacionando teoria e prática, tendo como foco central o processo educativo e a formação para o trabalho. Como metodologia da pesquisa, foi utilizado o ensaio, que baseia-se em referências bibliográficas representativas. O estudo foi apresentado em seções, nas quais para cada assunto abordado houve o desenvolvimento do conhecimento e aprofundamento sobre os temas, tais como: a concepção de avaliação da aprendizagem; avaliação como prática emancipatória; instrumentos utilizados nas práticas avaliativas na educação profissional; feedbacks para os estudantes; contribuições da avaliação da aprendizagem para o trabalho docente e os desafios da avaliação na Educação Profissional, Científica e Tecnológica (EPCT). Este estudo mostrou que a avaliação da aprendizagem como prática emancipatória se constitui, nesse segmento educacional, numa ação bastante complexa e fundamental para formação profissional dos estudantes.
Tropical plant species are vulnerable to climate change and global warming. Since flowering is a critical factor for plant reproduction and seed-set, warming and elevated atmospheric carbon dioxide ...concentrations (eCO
) are crucial climate change factors that can affect plant reproductive dynamics and flowering related events in the tropics. Using a combined free-air CO
enrichment and a free-air temperature-controlled enhancement system, we investigate how warming (+2 °C above ambient, eT) and elevated CO
(~600 ppm, eCO
) affect the phenological pattern, plant-insect interactions, and outcrossing rates in the tropical legume forage species Stylosanthes capitata Vogel (Fabaceae). In comparison to the control, a significantly greater number of flowers (NF) per plot (+62%) were observed in eT. Furthermore, in warmed plots flowers began opening approximately 1 h earlier (~09:05), with a canopy temperature of ~23 °C, than the control (~09:59) and eCO
(~09:55) treatments. Flower closure occurred about 3 h later in eT (~11:57) and control (~13:13), with a canopy temperature of ~27 °C. These changes in flower phenology increased the availability of floral resources and attractiveness for pollinators such as Apis mellifera L. and visitors such as Paratrigona lineata L., with significant interactions between eT treatments and insect visitation per hour/day, especially between 09:00-10:40. In comparison to the control, the additive effects of combined eCO
+ eT enhanced the NF by 137%, while the number of A. mellifera floral visits per plot/week increased by 83% during the period of greatest flower production. Although we found no significant effect of treatments on mating system parameters, the overall mean multilocus outcrossing rate (tm = 0.53 ± 0.03) did confirm that S. capitata has a mixed mating system. The effects of elevated CO
and warming on plant-pollinator relationships observed here may have important implications for seed production of tropical forage species in future climate scenarios.
RESUMEN Introducción: la comorbilidad es la presencia de enfermedades coexistentes o adicionales en relación al diagnóstico inicial o enfermedad guía. Es más frecuente en ancianos y contribuye a la ...aparición de eventos adversos de salud como mayor duración de la internación y mortalidad hospitalaria. Objetivo: determinar el efecto de las comorbilidades en la duración de la internación y en la mortalidad intrahospitalaria de los pacientes ingresados en el Servicio de Clínica Médica del Hospital Nacional (Itauguá, Paraguay) y del Hospital Militar Central (Asunción, Paraguay) entre marzo y julio del 2019. Materiales y métodos: se aplicó diseño de cohortes prospectivas en base al índice de comorbilidad de Charlson con punto de corte en 3 puntos. Ingresaron al estudio todos los varones y mujeres, mayores de 16 años, ingresados al Servicio de Clínica Médica del Hospital Nacional (Itauguá, Paraguay) y del Hospital Militar Central (Asunción, Paraguay) entre marzo y julio 2019. Se aplicó muestreo no probabilístico de casos consecutivos. Se midieron dos variables dependientes: duración de la hospitalización y mortalidad intrahospitalaria. Se calculó RR (IC 95%) y se consideró significativa toda p<0,05. El estudio respetó las normas éticas. Resultados: se incluyeron 543 sujetos, con predominio del sexo masculino (56%). La edad media fue 52±20 años. La mediana del índice de Charlson fue 2 puntos. No se detectó asociación estadísticamente significativa entre la severidad de este índice y la duración de la internación pero la mortalidad intrahospitalaria fue mayor con índice de Charlson ≥4: 6,5% vs 14,5% (p 0,005). Conclusiones: la mediana del índice de Charlson en dos Servicios de Clínica Médica fue 2. Se halló asociación estadísticamente significativa entre este índice y la mortalidad hospitalaria.
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