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Rio de Janeiro, Brazil

Ecological theory of habitat heterogeneity and limited niche-similarity assumes that more heterogeneous environments provide a greater amount and diversity of resources than simple environments, resulting in a greater diversity of species. This study aimed to evaluate the effect of the habitat heterogeneity on the richness of dung beetles and to examine the spatial patterns of assemblage structure in relation to patterns of habitat heterogeneity. Dung beetles were collected using pitfall traps without bait in 30 points distributed in an area of cerrado sensu lato, in the region of Tangará da Serra, MT, Brazil, including areas of cerrado sensu stricto, campo sujo, cerradão and gallery forest. A total of 1,291 dung beetles were collected, distributed in 16 genera and 29 species. Overall habitat heterogeneity exerted a negative effect on patterns of dung beetles richness. Higher levels of species richness were observed in areas of cerrado campo sujo, while the areas of gallery forest were the most species poor. Regarding assembly structure, it was found that the dung beetles were separated into two major groups, one formed by the presence of specialized species in forest areas and other composed of species that occurred predominantly in cerrado. In conclusion, it was found that habitat complexity infl uenced the distribution of dung beetles, but the level of turnover in species composition along the heterogeneity gradient was relatively weak. Source

Imperio G.E.D.,Federal University of Rio de Janeiro | Ramos I.P.,Hospital Universitario Clementino Fraga Filho | Ramos I.P.,Federal University of Rio de Janeiro | Santiago L.A.,Federal University of Rio de Janeiro | And 7 more authors.
Cellular Physiology and Biochemistry | Year: 2015

Background/Aims: Thyroid hormone (TH) signalling is critical for heart function. The heart expresses thyroid hormone receptors (THRs); THRα1 and THRβ1. We aimed to investigate the regulation mechanisms of the THRβ isoform, its association with gene expression changes and implications for cardiac function. Methods: The experiments were performed using adult male mice expressing TRβΔ337T, which contains the Δ337T mutation of the human THRB gene and impairs ligand binding. Cardiac function and RNA expression were studied after hypo-or hyperthyroidism inductions. T3-induced cardiac hypertrophy was not observed in TRβΔ337T mice, showing the fundamental role of THRβ in cardiac hypertrophy. Results: We identified a group of independently regulated THRβ genes, which includes Adrb2, Myh7 and Hcn2 that were normally regulated by T3 in the TRβΔ337T group. However, Adrb1, Myh6 and Atp2a2 were regulated via THRβ. The TRβΔ337T mice exhibited a contractile deficit, decreased ejection fraction and stroke volume, as assessed by echocardiography. In our model, miR-208a and miR-199a may contribute to THRβ-mediated cardiac hypertrophy, as indicated by the absence of T3-regulated ventricular expression in TRβΔ337T mice. Conclusion: THRβ has important role in the regulation of specific mRNA and miRNA in T3-induced cardiac hypertrophic growth and in the alteration of heart functions. © 2015 The Author(s) Published by S. Karger AG, Basel. Source

Cunha Jr. L.C.,University of Sao Paulo | Jacomino A.P.,University of Sao Paulo | Ogassavara F.O.,Sao Paulo State University | Trevisan M.J.,University of Sao Paulo | Parisi M.C.M.,IB
Horticultura Brasileira | Year: 2012

Temperature of 0°C associated to 12-20% CO2 has been recommended as the ideal conditions to store strawberries. However, fruits and vegetables are not currently handled under cold chain in Brazil and, when it happens, it used to be at 10 to 15°C. The goal of this work was to evaluate the quality and the shelf life of 'Oso Grande' strawberry at 10°C associated to high carbon dioxide concentrations. Strawberries were randomized, chilled and stored at 10°C in hermetic mini-chambers to apply the CO2 concentrations (0.03, 10, 20, 40 and 80%) plus 20% O2. Strawberries were analyzed every two days while they were proper to consumption. The shelf life for strawberries at 20 and 40% CO2 was 8 days, while those at 0.03% CO2 lasted only two days. Strawberries at 80% CO2 maintained good appearance for 6 days, but they were considered unsuitable for consumption due to high levels of acetaldehyde (40.92 μg g-1) and ethanol (1,053 μg g-1) that gave evidence of fermentation process. The weight loss was less than 2% showing how efficient was the method used to control the relative humidity during the storage. Strawberries at 0.03 and 80% CO2 levels showed higher firmness loss. Those fruits lost 40% of the initial firmness. Strawberries at 20 and 40% CO2 lost only 28% of initial firmness. Despite of the statistical effect of the treatments in the external color it was not visually perceptible. Strawberries stored at 10°C and 40% CO2 plus 20% O2 kept the marketable quality during 8 days. Source

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