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É possível predizer o teor de água das sementes de seis espécies florestais da Amazônia utilizando a atividade de água?
No full textMassive tree mortality from flood pulse disturbances in Amazonian floodplain forests: The collateral effects of hydropower production
No full textLarge dams built for hydroelectric power generation alter the hydrology of rivers, attenuating the flood pulse downstream of the dam and impacting riparian and floodplain ecosystems. The present work mapped black-water floodplain forests (igapó) downstream of the Balbina Reservoir, which was created between 1983 and 1987 by damming the Uatumã River in the Central Amazon basin. We apply remote sensing methods to detect tree mortality resulting from hydrological changes, based on analysis of 56 ALOS/PALSAR synthetic aperture radar images acquired at different flood levels between 2006 and 2011. Our application of object-based image analysis (OBIA) methods and the random forests supervised classification algorithm yielded an overall accuracy of 87.2%. A total of 9800 km 2 of igapó forests were mapped along the entire river downstream of the dam, but forest mortality was only observed below the first 49 km downstream, after the Morena rapids, along an 80-km river stretch. In total, 12% of the floodplain forest died within this stretch. We also detected that 29% of the remaining living igapó forest may be presently undergoing mortality. Furthermore, this large loss does not include the entirety of lost igapó forests downstream of the dam; areas which are now above current maximum flooding heights are no longer floodable and do not show on our mapping but will likely transition over time to upland forest species composition and dynamics, also characteristic of igapó loss. Our results show that floodplain forests are extremely sensitive to long-term downstream hydrological changes and disturbances resulting from the disruption of the natural flood pulse. Brazilian hydropower regulations should require that Amazon dam operations ensure the simulation of the natural flood-pulse, despite losses in energy production, to preserve the integrity of floodplain forest ecosystems and to mitigate impacts for the riverine populations. © 2018 Elsevier B.V
Frutooligossacarídeo aumenta lipoperoxidação lipídica em juvenis de tambaqui (Colossoma macropomum, Characiformes, Serrasalmidae) submetidos à privação alimentar
No full textUso e extrativismo do Angico numa comunidade indígena na savana de Roraima, norte da Amazônia brasileira
No full textDo climate changes alter the distribution and transmission of malaria? Evidence assessment and recommendations for future studies
Get PDFMalaria, a mosquito-borne infectious disease, is considered a significant global health burden. Climate changes or different weather conditions may impact infectious diseases, specifically those transmitted by insect vectors and contaminated water. Based on the current predictions for climate change associated with the increase in carbon dioxide concentrations in the atmosphere and the increase in atmospheric temperature, the Intergovernmental Panel on Climate Change predicts that in 2050, malaria may threaten some previously unexposed areas worldwide and cause a 50% higher probability of malaria cases. Climatebased distribution models of malaria depict an increase in the geographic distribution of the disease as global environmental temperatures and conditions worsen. Researchers have studied the influence of changes in climate on the prevalence of malaria using different mathematical models that consider different variables and predict the conditions for malaria distribution. In this context, we conducted a mini-review to elucidate the important aspects described in the literature on the influence of climate change in the distribution and transmission of malaria. It is important to develop possible risk management strategies and enhance the surveillance system enhanced even in currently malaria-free areas predicted to experience malaria in the future. © 2019, Sociedade Brasileira de Medicina Tropical. All rights reserved
GEEA - Caderno de Debates: TOMO XIV
No full textEste Tomo trata de temas altamente significativos para a Amazônia e que atuam de maneira conjunta, parecendo haver entre eles dependências mútuas: floresta, domesticação, subdesenvolvimento, Ciência & Ética. No primeiro capítulo é feita uma panorâmica histórica da presença do homem na Amazônia, tendo como foco sua interação com a floresta e a domesticação de plantas úteis para seu sustento. Ao lado do passado indígena em que houve forte domesticação da floresta, também são tecidas considerações sobre o período colonial, no qual se tentou importar e impor modelos de desenvolvimento de outras regiões, sem levar em consideração a verdadeira vocação da Amazônia e os legítimos interesses de seu povo. No segundo capítulo é traçado um paralelo entre a natureza da Ética e da Ciência e da relação histórica, desejável e mesmo necessário entre uma e outra. Invoca alguns mitos para evidenciar a força dos imperativos, interdições e afirmações sociais e para os quais não pode haver segredos
First pollen record for Ancyloscelis apiformes (Apidae: Emphorini) in Central Amazon
No full textThe first pollen study for the solitary bee Ancyloscelis apiformes (Emphorini) in a nest aggregation in the Central Amazon was made in October 2012 at the Sucupira apiary in east Manaus, Amazonas, at 03° 00ʹ 05″ S, 59° 51ʹ 05″ W. A total of 15 samples/nests (N1–N15) were analysed, including intact pollen loads (stored inside the nest) and post-emergence residues, which were acetolysed and mounted in glycerine gelatin. From each sample, 500 pollen grains were counted to determine the pollen frequencies and diversity (H′) and evenness (J′) indices. The most representative pollen types were Bonamia ferruginea (N1 = 95.6% and N2 = 96.00%) and the Ipomoea (N3 = 96.40%), both of which belong to the Convolvulaceae. In addition, Byrsonima crispa (N10 = 93.40%) and Malpighia glabra (N7 = 90.20% and N9 = 97.60%), representatives of the Malpighiaceae, were classified as temporary specialisation events with frequencies above 90%. In this study, A. apiformes, which is considered an oligolectic bee species, presented a polylectic tendency since it collected large percentages of pollen types from plants in distinct families that were not phylogenetically related. © 2019, © 2019 Collegium Palynologicum Scandinavicum
Dietas para a engorda de pirarucu em tanque rede: Desempenho, parâmetros fisiológicos, composição do filé e custos da alimentação
Get PDFThe present study evaluated practical diets with increasing levels of protein and energy on performance, fillet composition, feed cost, and physiological responses of pirarucu (Arapaima gigas) juveniles during the grow-out phase in a net cage system. In an on-farm trial for 90 days 225 pirarucu juveniles with initial weight ± standard deviation of 2025 ± 335 g were fed to apparent satiety with extruded diets containing 37.4 (T-37), 40.8 (T-40), 43.9 (T-43), 45.5 (T-46), and 47.1% (T-49) crude protein (CP), increasing lipid levels, and energy:protein ratio fixed in 10 kcal g-1. Protein and lipid concentrations in the diets influenced the cost, fillet composition, and important physiological aspects of the health maintenance and productive performance of the pirarucu juveniles. Fish fed the T-37 diet had lower concentrations of fat in body cavity, fillet and blood, and had a lower cost associated with feeding. The increase in protein and energy levels in the other diets tested reduced the economic return, did not improve the zootechnical performance and caused physiological changes in the fish. © 2019, Instytut Technologii Drewna. All rights reserved
