178 research outputs found

    Montagem De Comunidades: Conceitos, Domínio E Estrutura Teórica

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    Community assembly refers to any ecological process that operates to select species from a regional pool and put them together in local communities. Initially, Diamond (1975) proposed a community assembly model based on rules explaining the checkerboard distribution of co-occurring bird species in New Guinea archipelago. By that time, the assembly rules proposed interspecific competition as the only plausible explanation for the patterns observed. However, the lack of testable predictions, inappropriate statistical analyses and, mainly, the absence of alternative hypotheses have represented an obstacle for the theory development. With the introduction of phylogenetic/functional analyses in community studies, a meaningful increase of published papers on community assembly has been noticed, mainly due to the development of models providing more predictive power to assembly processes. Hence, we decided to elaborate a critical review about the conceptual progress in the community assembly theory. We point out that a) the community assembly theory has enhanced its predictive power when it became to be associated with solid statistics; b) the hypothesis test by null models has been reinforced as a consistent data analysis method applied in many studies; and c) the neutral theory has been used as a satisfactory alternative to the coexistence hypothesis by deterministic niche-based processes. However, the community assembly theory is not fully mature yet but has a high potential of near-future development, mainly through the consolidation of its conceptual base. We hope that our review can help in this development by systematizing the community assembly theory and clarifying some misunderstood and/or so-far poorly applied concepts. © 2016, Universidade Federal do Rio de Janeiro (UFRJ). All rights reserved.20111

    Incorporating oldman saltbush hay and prickly pear in diets for red Sindhi calves

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    This study was designed to evaluate the nutrient intake, digestibility, degradability, and ruminal characteristics of Sindhi heifers fed diets that contained a combined total of 75% oldman saltbush hay (hereafter saltbush hay) and prickly pear cactus. Eight 12-month old intact male red Sindhi calves (four fistulated and four non-fistulated) with an initial mean weight of 170 ± 5 kg were assigned to 4 × 4 Latin squares, where factors consisted of four diets, namely 15% hay and 60% cactus; 30% hay and 45% cactus; 45% hay and 30% cactus; and 60% hay and 15% cactus, and four times at which rumen fluid was collected. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) intakes in kg/day and NDF in percentage live weight (LW), water intake, salinity, and conductivity increased with hay level. Intake and digestibility of non-fibrous carbohydrates were curvilinear with higher values in diets containing 30% saltbush hay. The apparent digestibility of dry matter (DM) and organic matter decreased linearly as the concentration of saltbush hay increased in the diet. The pH of the rumen fluid was within the acceptable range for favourable microbial growth. The low temperature and high salinity and conductivity indices in the diets should be viewed with caution at higher concentrations of saltbush hay, because of a possible decrease in nutrient absorption and the development of health problems in the animals. Apparent degradability coefficients of DM and NDF were affected significantly by inclusion of prickly pear and saltbush hay in the diets.Keywords: animal nutrition, apparent digestibility, Atriplex nummularia Lindl, Opuntia ficus, ruminal degradation, semi-arid environmen

    Metabolic profile and histopathology of kidneys and liver of lambs fed silages of forages adapted to a semi-arid environment

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    Thirty-two mixed-breed ram lambs (average age, 5.6 ± 0.4 months, and average live weight, 17.61 ± 2.63 kg) were used to evaluate the effect of diets containing silages of forages adapted to a semi-arid environment on the metabolic profile in serum and the histopathological assessment of liver and kidney tissues of the lambs. Lambs were allocated, in a completely randomised design, to four treatments (silage of old man saltbush (Atriplex nummularia Lind), buffelgrass (Cenchrus ciliaris), gliricidia (Gliricidia sepium) and ‘pornunça’ (Manihot sp.). The feedlot period was 49 days, and animals were slaughtered at an average weight of 27 ± 4.6 kg. On the last day of the experiment, blood was collected from the jugular vein of all animals to measure the protein, metabolic and energy profiles of the lambs. At slaughter, kidney and liver samples were collected for histopathological examination. The consuming of the diet containing buffelgrass silage resulted in a significantly higher activity of alanine-aminotransferase (30.14 IU/L) and the concentrations of urea (44.25 mg/dL), creatinine (0.94 mg/dL) and albumin (4.48 g/dL) in serum. Diets containing gliricidia silage resulted in significantly higher gamma-glutamyl transferase activity (92.0 IU/L), while the diets with pornunça silage resulted in higher serum levels of triglycerides (37.85 mg/dL). The diets had no effect on aspartate-aminotransferase enzyme activity and total protein, cholesterol and globulin concentrations, or the albumin : globulin ratio in serum. Mild congestion, necrosis and foci of mineralisation were observed in the kidneys of animals fed diets containing old man saltbush (50%) and pornunça (25%) silages, and mild fatty degeneration and mild mononuclear inflammatory infiltrate in their livers. In conclusion, diets containing silages of forages that are adapted to semi-arid environments may be used for feeding lambs, given the absence of dysfunctioning plasmatic levels of liver enzymes and energy and protein profiles. Additionally, kidney failure was not observed in lambs fed these diets during the feedlot period.Keywords: blood parameters, buffelgrass, gliricidia, old man saltbush, pornunç

    Characteristics of carcass and non-carcass components of lambs fed diets containing silages of forages adapted to the semi-arid environment

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    The aim of this study was to evaluate the effects of diets containing silages of forages that are adapted to the semi-arid environment on the characteristics of the carcass and of non-carcass components of 32 mixed-breed lambs at approximately six months old, with an average live weight of 17.61 ± 2.63 kg. Lambs were assigned to four treatments (diets containing silages of Atriplex nummularia Lind, Cenchrus ciliaris, Gliricidia sepium and Manihot sp.) in a completely randomized design with eight replicates. Animals fed the diet containing old man saltbush showed higher values for the intakes of dry matter (1.080 g/day), crude protein (190 g/day) and total digestible nutrients (740 g/day), body condition score (2.81 points), fatness (2.87 points), carcass conformation (3.19 points), live weight (29.1 kg), empty bodyweight (23.41 kg), weights of the commercial cuts neck, shoulder and ribs (0.46, 0.82 and 1.12 kg, respectively), and skin weight (1.972 kg). No differences were found between the diets for carcass dressing percentage, external and internal carcass lengths, leg length and circumference, rump circumference and width, chest width and depth, full bodyweight, empty bodyweight, cooling losses, pH before and after cooling, loin, and leg. Silages of old man saltbush, buffelgrass, gliricidia and pornunça are recommended for inclusion in lamb diets. Diets with old man saltbush silage provide the best results for characteristics of the carcass and of non-carcass components besides weight gain, which can reach up to 200 g/day depending on the formulation.Keywords: Carcass composition, feedlot, saltbush, shee

    Carcass characteristics and meat quality of sheep fed buffelgrass silage to replace corn silage

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    The aim of the study was to evaluate the carcass characteristics, proximate composition, and sensorial attributes of meat from sheep fed diets in which buffelgrass silage replaced corn silage. Thirty-two intact male crossbred Santa Inês sheep with an average live weight of 20.09 ± 2.0 kg were housed in individual stalls and allotted at random to four treatments in which corn silage was replaced by buffelgrass silage at the levels of 0 (control), 33.3%, 66.6%, and 100%. After an adaption period of 10 days, the sheep were fed for an additional 61 days. Feed was offered ad libitum and corn silage comprised 60% of the diet for the control group. Carcass characteristics, non-carcass components and meat quality were evaluated. Hot carcass yield, cold carcass yield, true carcass yield, trimmings, fat weight, and mesenteric and omental fat weight were highest for the control group (P <0.05). Loin eye area had a quadratic response (P =0.02), with the largest areas being observed in animals fed the diet containing 66.6% buffelgrass silage. Liver weight (P <0.01), luminosity of the meat (P <0.05), and cooking loss (P <0.05) likewise had nonlinear responses to the concentration of buffelgrass silage in the diet. The treatments did not have significant negative influence on the nutritional and organoleptic characteristics of the meat

    CURSO DE FORMAÇÃO PEDAGÓGICA PARA MONITORES DA UFAPE: CONTRIBUIÇÕES ACADÊMICAS E PROFISSIONAIS

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    Nesse artigo a partir da experiência vivenciada no projeto de ensino coordenado pela Comissão de Ensino, em parceria com a Coordenação Geral de Cursos de Graduação, da Unidade Acadêmica de Garanhuns (UFRPE), atual Universidade Federal do Agreste de Pernambuco - UFAPE, em 2019, analisam-se as contribuições do curso para formação dos monitores para a formação acadêmica e profissional dos estudantes participantes do evento. Adota como fundamentação teórica os estudos de Lee Shulman que investigam conhecimentos necessários para o ensino. Os dados foram coletados por meio de um formulário on-line composto, em sua maior parte, por perguntas que deveriam ser respondidas atribuindo pontuação de 1 a 5, utilizando a escala de Likert. O perfil dos participantes foi diversificado, incluindo discentes ligados aos programas de monitoria e tutoria bolsistas ou voluntários. As motivações, indicadas pelos discentes participantes do curso, para ingresso nos programas de monitoria ou tutoria estão alinhadas com as definidas na resolução UFRPE 262/2001. Os participantes citaram positivamente a relação dos temas tratados com as atividades práticas da monitoria destacando-se o estímulo à profissão docente, especialmente ao contribuir para o desenvolvimento de conhecimentos pedagógicos, sobre avaliação; aprendizagem; metodologias de ensino, entre outros, importantes aspectos para a profissionalização docente
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