826 resultados para Ecological and environmental anthropology
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Genetic and environmental effects on parturition interval (PI) and duration of lactation (DL) were evaluated in 107 Jafarabadi, 98 Mediterranean, 1027 Murrah and 624 crossbred buffalo females (n=1856), based on data from the Buffalo Genetic Improvement Program-PROMEBUL from 1980 to 2003. The statistical model included effects of herd, parturition year and month, calf's sex, parturition order and genetic group, composing 11, 34, 12, 2, 12 and 4 classes, respectively. A significant effect over PI was observed (P<0.01) in all classes, excepting sex. Mean parturition intervals per genetic group presented significant differences through SNK test (P<0.05), with mean values of 451.29; 429.47; 406.97 and 389.78 days in Mediterranean, crossbred, Murrah and Jafarabadi, respectively. Mean DL values were 276.68; 270.33; 258.03 and 235.59 days for Mediterranean, Murrah, crossbred and Jafarabadi groups, respectively. No significant differences in DL were observed in relation to genetic groups. However, herd and parturition order, year and month significantly influenced DL (P<0.01). The herd was the main source of variation over DL, followed by parturition year and month. A regression based on parturition month in relation to PI and DL showed that females giving birth in the last months of the year presented higher PI and DL.
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The main goal of this study was to identify and analyse environmental problems related to human occupation at the south part of the city of Paranagua PR, Brazil, aiming the diagnosis and conceptual evaluation of landscape use. For landscape use assessments and degradation diagnosis purposes, the environment was classified considering mainly geological and geomorphologic characteristics, such as declivity and sediment origin. The identification of potential environmental impacts was made by aerial photographs, Landsat-TM images, photographic records, surface sediment samples, water-column samples, and mainly observation visits to each classified unit. Surface sediment samples were taken with a Petit-Ponar sampler, in 13 station located in Paranagua Bay. In order to characterize the contamination level on sediments, the concentration of the following elements were analysed: arsenic (As), copper (Cu), cadmium (Cd), nickel (Ni), lead (Ph) e zinc (Zn). For the extraction of these elements, samples were treated with HCl 0.1N for 12 hours. This method has the advantage of determining contaminants which are weakly bind to the sediment, thus more available to the system. Analysis were performed by atomic absorption spectroscopy. According to the adopted criteria, sectors were classified as hills, mangroves, continental sediments and beach ridges urban and port industrial. Water quality and concentrations of metallic elements were determined at three sectors one control and two with the influence of urban and port/industrial activities, respectively the major upland impacts found were: deforestation due to disordered occupation, and solid waste emission through domestic and industrial sewage. The diagnosis of the actual situation was used as a basis for a management plan, once it allows the identification of impacts, and consequent environmental irregularities. Based on this considerations, suggestions for land use and management were presented, which offers a better approach for recuperation and protection of the studied ecosystem.
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This investigation was carried out to study the influence of early qualitative feed restriction and environmental rearing temperature on long bone development in broiler. Energy and protein restriction reduced femur width and humerus weight, but did not affect tibia parameters. Broilers kept at cold environmental temperature showed reduced femur, tibia and humerus length and tibia weight, but the calculated density was not affected by rearing temperature. These findings suggest that qualitative feed restriction and environmental temperature influenced the normal long bone growth; however, bone weight/bone length index (calculated density) was not affected by rearing temperature. (c) 2007 Elsevier Ltd. All rights reserved.
Natural Conditions and Environmental Impacts in a Coastal Hydrographic Basin in the Brazilian Amazon
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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A total of 88 Aeromonas isolates from distinct locations and sources (39 from extraintestinal infections, 31 from diarrhoeic, ten from non-diarrhoeic faeces, all human, and eight from fresh water) were subjected to phenospecies identification, serotyping, ribotyping and detection of some virulence markers. The strains belonged to four different phenospecies marked by 19 O serogroups and 38 ribotypes. No strong correlation between these parameters was found, and no group, as defined by the typing methods, could be characterized with a particular set of virulence markers. There was a clear association of ribotypes with the source of the strains. Cluster analysis allowed the identification of a complex of ribotypes belonging to distinct but related sources, including clinical and environmental isolates. These results suggest that ribotyping may be an epidemiological tool suitable for the study of Aeromonas infections.
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Alluvial paleosoil horizons from the 3 to 4 m high banks of the Paraná River were used to reconstruct the palaeoenvironmental history and palaeohydrological regime of the river. The bank consists of a Middle to Late Holocene sequence of sandy to silty clay layers of overbank deposits. The paleosoil horizon is located to a depth of 1.95 m from the top of the bank and is recognized as a guide horizon throughout the floodplain of the Upper Paraná River floodplain. Analyses of organic matter (δ13C and humic/fulvic acids), palynology (pollen and charcoal fragments), magnetic susceptibility, micromorphology, x-ray diffraction and 14C dating were conducted for samples from two representative profiles of the study area. Two phases were characterized in the history of the river: 1) An older phase, of stability in fluvial hydrology (stasis) with low frequency of floods, which produced conditions for soil development (14C 1700 ± 70 yr. BP). At this period, the predominance of herbaceous vegetation (determinated by pollen and δ13C analyses) suggests a climate less humid than the present one, and 2) A second phase, when climate changed to the present conditions of humidity (annual rain fall of 1600 rum) and characterized by the predominance of C3 plants. Under this new hydrological regime, the river developed an agradational floodplain, with a depositional sedimentary rate of 1.2 mm.y-1. © 2006 Gebrüder Borntraeger.
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We examined the relationships between topography, soil properties and tree species composition in a Neotropical swamp forest in southeastern Brazil. Plots were sampled in the forest, encompassing three different soil ground water regimes along the topographical declivity. All non-climbing plant individuals with trunk height >1.3 m were sampled. A canonical correspondence analysis-CCA-of the species-environmental relationships grouped tree species according to drainage and chemical soil conditions. A total of 86 species were found, being 77 species in the inferior, 40 species in the intermediate and 35 species in the superior topographic section. Some species were among the 10 most abundant ones, both in the overall sampled area and in each topographical section, with alternation events occurring only with their abundance position. However, substantial differences in floristic composition between sections were detected in a fine spatial scale, due to higher number of species, diversity index (H′) and species unique (exclusives) in the inferior topographic section. These higher values can be attributed to its higher spatial heterogeneity that included better drained and seasonally waterlogged soils, higher soil fertility and lower acidity. The increase of the soil water saturation and the uniform conditions derived from the superficial water layer has led to a lower number of species and an increase on the palm trees abundance in the intermediate and superior sections. Our results showed that at a small spatial scale niche differentiation must be an important factor related to the increase of the local diversity. The wide distribution of the most abundant species in the studied area and the increase of local diversity corroborate the pattern of distribution of species in larger scales of swamp forests, in which the most abundant species repeat themselves in high densities in different remnants. However, the floristic composition of each remnant is strongly variable, contributing to the increase of regional diversity. © 2008 Springer Science+Business Media B.V.
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Includes bibliography
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Includes bibliography
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Incluye Bibliografía
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Bibliografía sobre desarrollo de las áreas costeras, planificación del medio ambiente, recursos marinos, planificación regional y física, y puertos del Caribe.
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Includes bibliography
Functional Redundancy and Complementarities of Seed Dispersal by the Last Neotropical Megafrugivores
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Background: Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest. Methodology/Principal Findings: We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest. Conclusions/Significance: Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers. © 2013 Bueno et al.