Detection of salt marsh vegetation stress and recovery after the Deepwater Horizon Oil Spill in Barataria Bay, Gulf of Mexico using AVIRIS data.

The British Petroleum Deepwater Horizon Oil Spill in the Gulf of Mexico was the biggest oil spill in US history. To assess the impact of the oil spill on the saltmarsh plant community, we examined Advanced Visible Infrared Imaging Spectrometer (AVIRIS) data flown over Barataria Bay, Louisiana in September 2010 and August 2011. Oil contamination was mapped using oil absorption features in pixel spectra and used to examine impact of oil along the oiled shorelines. Results showed that vegetation stress was restricted to the tidal zone extending 14 m inland from the shoreline in September 2010. Four indexes of plant stress and three indexes of canopy water content all consistently showed that stress was highest in pixels next to the shoreline and decreased with increasing distance from the shoreline. Index values along the oiled shoreline were significantly lower than those along the oil-free shoreline. Regression of index values with respect to distance from oil showed that in 2011, index values were no longer correlated with proximity to oil suggesting that the marsh was on its way to recovery. Change detection between the two dates showed that areas denuded of vegetation after the oil impact experienced varying degrees of re-vegetation in the following year. This recovery was poorest in the first three pixels adjacent to the shoreline. This study illustrates the usefulness of high spatial resolution airborne imaging spectroscopy to map actual locations where oil from the spill reached the shore and then to assess its impacts on the plant community. We demonstrate that post-oiling trends in terms of plant health and mortality could be detected and monitored, including recovery of these saltmarsh meadows one year after the oil spill.

Levantamento, cadastramento e estimativa populacional das habitações de morcegos hematófagos, antes e após atividades de controle, no município de araguari, mg

ABSTRACT Vampire bats are responsible for the transmission of herbivorous rabies, a zoonosis of the greatest importance to public health. In the present study the habitats of these bats were investigated in the County of Araguari, MG, Brazil, in the period between 1996 and 2003. The objective of the investigation was to locate and register the natural and artificial shelters with hematophagous bats, estimating the median population of the colonies and the identification of the species found therein, having in mind their population control. A total of 54 shelters of Desmodus rotundus, the most frequently found hematophagous bat in Brazil were registered and grouped in 12 different kinds. In terms of their location, 81.5% of these shelters were in man-made objects, listed in regard to the decreasing order of their frequency: houses, drains, small bridges, bridges, etc., while 18.5% were in natural sites, of which caves and hollows in trees were the most frequent. Of the shelters inhabited by D. rotundus, 82.4% had an estimated population between 1 to 50 individuals, while 17.6% had between 51 and 300 individuals, with a median population of 30.2 per shelter. After treatment with Warfarin, 72.5% of the shelters were unoccupied. For effective control of rabies in herbivores it is necessary to maintain a routine registry of shelters with monitoring at least once a year.

RESUMO Os morcegos hematófagos são responsáveis pela transmissão da raiva dos herbívoros, zoonose de maior importância em saúde pública. Neste estudo, foram pesquisadas habitações desses morcegos no Município de Araguari, MG, no período entre 1996 e 2003, com o objetivo de localizar e cadastrar abrigos naturais e artificiais que acolhiam hematófagos, visando controle populacional, estimativa da mediana nas colônias e identificação das espécies encontradas. Foram cadastrados 54 abrigos, agrupados em 12 tipos diferentes, do Desmodus rotundus, espécie de hematófago mais frequente no Brasil. Dentre o total de abrigos 81,5% eram artificiais, conforme ordem decrescente de suas frequências: casas, bueiros, pontilhões, pontes, etc., enquanto que entre os 18,5% dos naturais, as cavernas e ocos de árvores foram os mais frequentes. Dos abrigos habitados pelo D. rotundus, 82,4% possuíam população estimada entre 1 a 50 hematófagos e 17,6% entre 51 a 300 indivíduos, com população mediana de 30,2 por abrigo. Após o tratamento com warfarina, 72,5% dos abrigos foram desabitados. Para o controle efetivo da raiva dos herbívoros é necessário que se mantenha uma rotina de cadastro dos abrigos, com monitoramento de pelo menos uma vez por ano.

The rate and extent of deforestation in watersheds of the southwestern Amazon basin.

The rate and extent of deforestation determine the timing and magnitude of disturbance to both terrestrial and aquatic ecosystems. Rapid change can lead to transient impacts to hydrology and biogeochemistry, while complete and permanent conversion to other land uses can lead to chronic changes. A large population of watershed boundaries (N=4788) and a time series of Landsat TM imagery (1975-1999) in the southwestern Amazon Basin showed that even small watersheds (2.5-15 km2) were deforested relatively slowly over 7-21 years. Less than 1% of all small watersheds were more than 50% cleared in a single year, and clearing rates averaged 5.6%/yr during active clearing. A large proportion (26%) of the small watersheds had a cumulative deforestation extent of more than 75%. The cumulative deforestation extent was highly spatially autocorrelated up to a 100-150 km lag due to the geometry of the agricultural zone and road network, so watersheds as large as approximately 40000 km2 were more than 50% deforested by 1999. The rate of deforestation had minimal spatial autocorrelation beyond a lag of approximately 30 km, and the mean rate decreased rapidly with increasing area. Approximately 85% of the cleared area remained in pasture, so deforestation in watersheds of Rondônia was a relatively slow, permanent, and complete transition to pasture, rather than a rapid, transient, and partial cutting with regrowth. Given the observed landcover transitions, the regional stream biogeochemical response is likely to resemble the chronic changes observed in streams draining established pastures, rather than a temporary pulse from slash-and-burn.

Eficácia dos coadjuvantes de higiene bucal utilizados na alimentação de cães

The use of coadjutants in the decrease of the bacterial plate and formation of the dental calculus was evaluated in 16 dogs. The experimental design was randomized with four treatments (T) and four repetitions. The treatments were the following: 1- control; 2- coadjutant 1 (one) with mechanical action; 3- coadjutant 2 (two) with tripolyphosphate of sodium and 4- coadjutant 3 (three) with hexametaphosphate of sodium. After seven days of adaptation, on the day previous to the beginning of the treatments, the animals were submitted to the removal of dental calculus and after twenty-one days of treatment a measurement of the bacterial plaque formed through the use of markers (fucsin). The coadjutant only with mechanical action was not effective in delaying the appearance of the bacterial plaque. The coadjutant containing polyphosphates presented an effective and significant action decreasing the formation of the dental calculus.

Avaliou-se a utilização de coadjuvantes na diminuição da placa bacteriana e formação do cálculo dentário em 16 cães. O delineamento experimental foi casualizado com quatro tratamentos (T) e quatro repetições. Os tratamentos foram: T1- controle, T2- coadjuvante com ação mecânica, T3- coadjuvante com tripolifosfato de sódio e T4- coadjuvante com hexametafosfato de sódio. Após sete dias de adaptação, no dia anterior ao início dos tratamentos, os animais foram submetidos à remoção de cálculo dentário. O experimento teve duração de 21 dias e ao final realizaram-se as medições das placas bacterianas formadas com o uso de marcadores (fucsina). O coadjuvante somente com ação mecânica não foi efetivo em retardar o aparecimento da placa bacteriana. Os coadjuvantes com polifosfatos apresentaram uma ação efetiva e significativa na diminuição da formação do calculo dentário.

Técnicas avançadas de sensoriamento remoto aplicadas ao estudo de mudanças climáticas e ao funcionamento dos ecossistemas amazônicos / Advanced remote sensing techniques for global changes and Amazon ecosystem functioning studies

Este artigo se propõe a apresentar exemplos de questões científicas que puderam ser respondidas no contexto do Projeto LBA (Large Sale Biosphere-Atmosphere Experiment in Amazonia) graças à contribuição de informações derivadas de sensoriamento remoto. Os métodos de sensoriamento remoto permitem integrar informações sobre os vários processos físicos e biológicos em diferentes escalas de tempo e espaço. Nesse artigo, são enfatizados aqueles avanços de conhecimento que jamais seriam alcançados sem a concorrência da informação derivada de sensoriamento.

Técnicas avançadas de sensoriamento remoto aplicadas ao estudo de mudanças climáticas e ao funcionamento dos ecossistemas amazônicos

This paper aims to assess the contribution of remote sensing technology in addressing key questions raised by the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). The answers to these questions foster the knowledge on the climatic, biogechemical and hydrologic functioning of the Amazon, as well as on the impact of human activities at regional and global scales. Remote sensing methods allow integrating information on several processes at different temporal and spatial scales. By doing so, it is possible to perceive hidden relations among processes and structures, enhancing their teleconnections. Key advances in the remote sensing science are summarized in this article, which is particularly focused on information that would not be possible to be retrieved without the concurrence of this technology.

Este artigo se propõe a apresentar exemplos de questões científicas que puderam ser respondidas no contexto do Projeto LBA (Large Sale Biosphere-Atmosphere Experiment in Amazonia) graças à contribuição de informações derivadas de sensoriamento remoto. Os métodos de sensoriamento remoto permitem integrar informações sobre os vários processos físicos e biológicos em diferentes escalas de tempo e espaço. Nesse artigo, são enfatizados aqueles avanços de conhecimento que jamais seriam alcançados sem a concorrência da informação derivada de sensoriamento.

Carboxypeptidase-like activity during development and aging of Nippostrongylus brasiliensis.

An acid carboxypeptidase whose activity, based on several biochemical parameters, was determined to be similar to mammalian lysosomal carboxypeptidase was maximal at pH 5.0 during the early parasitic stages of development of the nematode Nippostrongylus brasiliensis. No such enzyme activity could be detected in the early free-living larval stages of this nematode. Carboxypeptidase activity declined as the age of the parasitic adult increased. Timing of maximum activity corresponds to the shift from free-living to parasitic stages of the life cycle.