2,356 research outputs found

    A qualidade da água da Lagoa Jacuném (Espírito Santo, Brasil) em relação a aspectos genotóxicos e mutagênicos, mensurados respectivamente pelo ensaio do cometa e teste do micronúcleo em peixes da espécie Oreochromis niloticus

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    For the assessment of water quality, physical-chemical criteria must be added to biotic aspects that can be measured by cytogenetic tests. Evolutionarily close, the fish have metabolism similar to that of higher vertebrates when exposed to harmful chemicals. Oreochromis niloticus (Linnaeus, 1758) is a very good test-model for researches using the micronucleus test and comet assay, for assessment of genotoxic and mutagenic effects. The Pond Jacuném, municipality of Serra/ES, plays an important socioeconomic role. Its drainage basin is occupied by residential and industrial areas which enhance the process of eutrophication. The assessment of water quality occurred during high and low rainfall seasons in three take sampling sites. In laboratory, samplied water were stored in reservoirs with alevins. Two reservoirs corresponded the negative (water with quality) and controls (cyclophosphamide injected). After 72 hours, fish were anaesthetized and blood taken to perform the micronucleus test and comet assay. Values of physicochemical parameters indicates that the WQI (Water Quality Index) was considered good, but other parameters showed values outside of the range levels accepted by the legislation, including metals Al and Cd. It is suggested that the pond is impacted due to effluents input. The results of the micronucleus test and comet assay indicate high mutagenic and genotoxic potential. The mutagenicity and genotoxicity may be related to the presence of chemicals. The highest values of genotoxicity and mutagenicity occurred during the rainfall period of the pond. It is concluded that the pond has a high genotoxic and mutagenic potential.Para a avaliação da qualidade da água, os critérios físico-químicos devem ser somados a aspectos bióticos que podem ser mensurados por testes citogenéticos. Evolutivamente próximos, os peixes apresentam metabolismo similar ao dos vertebrados superiores quando expostos a químicos nocivos. Oreochromis niloticus (Linnaeus, 1758) é ótimo modelo-teste para investigações a partir do ensaio do cometa e teste do micronúcleo, para avaliação da genotoxicidade e mutagenicidade. A Lagoa Jacuném, localizada no município de Serra/ES, desempenha importante papel socioeconômico. Sua bacia de drenagem é ocupada por áreas residenciais e industriais que intensificam o processo de eutrofização. A avaliação da qualidade da água ocorreu durante época de alta e baixa precipitação em três pontos amostrais. Em laboratório, amostras de água foram armazenadas em reservatórios com alevinos. Dois aquários corresponderam aos controles negativo (água com qualidade) e positivo (ciclofosfamida injetada). Após 72 horas, os peixes foram anestesiados e o sangue retirado para realizar o teste do micronúcleo e o ensaio do cometa. Valores dos parâmetros físico-químicos revelam que o IQA (Índice de Qualidade da Água) foi considerado bom, todavia outros parâmetros apresentaram valores fora do espectro aceito pela legislação, inclusive os metais Al e Cd. Sugere-se que a lagoa encontra-se impactada devido ao aporte de efluentes. Os resultados do teste do micronúcleo e ensaio do cometa indicam elevados potenciais mutagênico e genotóxico. A mutagenicidade e genotoxicidade podem estar relacionadas à presença de químicos. Os maiores valores de genotoxicidade e mutagenicidade ocorreram durante o período de chuva. Conclui-se que a lagoa apresenta elevado potencial genotóxico e mutagênico

    Anthelmintic Activity In Vivo of Epiisopiloturine against Juvenile and Adult Worms of Schistosoma mansoni

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    Schistosomiasis is a serious disease currently estimated to affect more that 207 million people worldwide. Due to the intensive use of praziquantel, there is increasing concern about the development of drug-resistant strains. Therefore, it is necessary to search for and investigate new potential schistosomicidal compounds. This work reports the in vivo effect of the alkaloid epiisopiloturine (EPI) against adults and juvenile worms of Schistosoma mansoni. EPI was first purified its thermal behavior and theoretical solubility parameters charaterised. In the experiment, mice were treated with EPI over the 21 days post-infection with the doses of 40 and 200 mg/kg, and 45 days post-infection with single doses of 40, 100 and 300 mg/kg. The treatment with EPI at 40 mg/kg was more effective in adult worms when compared with doses of 100 and 300 mg/kg. The treatment with 40 mg/kg in adult worms reduced parasite burden significantly, lead to reduction in hepatosplenomegaly, reduced the egg burden in faeces, and decreased granuloma diameter. Scanning electron microscopy revealed morphological changes to the parasite tegument after treatment, including the loss of important features. Additionally, the in vivo treatment against juvenile with 40 mg/kg showed a reduction of the total worm burden of 50.2%. Histopathological studies were performed on liver, spleen, lung, kidney and brain and EPI was shown to have a DL50 of 8000 mg/kg. Therefore EPI shows potential to be used in schistosomiasis treatment. This is the first time that schistosomicidal in vivo activity of EPI has been reported

    Semantic segmentation of tree-canopy in urban environment with pixel-wise deep learning

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    Urban forests are an important part of any city, given that they provide several environmental benefits, such as improving urban drainage, climate regulation, public health, biodiversity, and others. However, tree detection in cities is challenging, given the irregular shape, size, occlusion, and complexity of urban areas. With the advance of environmental technologies, deep learning segmentation mapping methods can map urban forests accurately. We applied a region-based CNN object instance segmentation algorithm for the semantic segmentation of tree canopies in urban environments based on aerial RGB imagery. To the best of our knowledge, no study investigated the performance of deep learning-based methods for segmentation tasks inside the Cerrado biome, specifically for urban tree segmentation. Five state-of-the-art architectures were evaluated, namely: Fully Convolutional Network; U-Net; SegNet; Dynamic Dilated Convolution Network and DeepLabV3+. The experimental analysis showed the effectiveness of these methods reporting results such as pixel accuracy of 96,35%, an average accuracy of 91.25%, F1-score of 91.40%, Kappa of 82.80% and IoU of 73.89%. We also determined the inference time needed per area, and the deep learning methods investigated after the training proved to be suitable to solve this task, providing fast and effective solutions with inference time varying from 0.042 to 0.153 minutes per hectare. We conclude that the semantic segmentation of trees inside urban environments is highly achievable with deep neural networks. This information could be of high importance to decision-making and may contribute to the management of urban systems. It should be also important to mention that the dataset used in this work is available on our website

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

    Generalidades sobre o quadro clínico da Rinossinusite: uma revisão narrativa de literatura: Generalities about the clinical picture of Rhinosinusitis: a narrative literature reviewv

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    A rinossinusite é um processo inflamatório da mucosa dos seios paranasais e da cavidade nasal. O sistema nasossinusal é responsável pelo balanço adequado entre a fabricação e o clearence de muco nas cavidades paranasais. A fisiologia deste é de vital importância para a proteção das vias aéreas superiores. No advém, determinados fatores podem acarretar um desbalanço nesse complexo, consequentemente um processo inflamatório. Qualquer fator que altere a drenagem, seja por obstrução, maior produção ou espessamento do muco, como processo infecciosos ou alérgicos, haverá uma impactação de secreções e a facilitação de colonização bacteriana, dando início ao processo infeccioso. A identificação da inflamação do nariz e seios paranasais é basicamente clínica. A suspeição desta ocorre através da manifestação de dois ou mais sintomatologias. As quais são o bloqueio ou obstrução nasal, a descarga nasal, pressão ou dor facial e redução ou perda do olfato. De modo geral, é essencial à prevenção básica das rinossinusites agudas é barrar a infecção viral. O suporte inclui medidas gerais de higiene, alimentação e hidratação, imunização para o combate de vírus respiratórios , administração de fármacos para turbinar o sistema imune se necessário

    Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

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    In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

    Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

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    The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle
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