Spatio-temporal distribution of fish larvae in relation to ontogeny and water quality in the oligohaline zone of a North Brazilian estuary

O padrão de distribuição das larvas de peixes na Baía do Guajará foi estudado através de coletas trimestrais e discutido em relação aos estágios de desenvolvimento dos indivíduos e a exposição dos mesmos aos contaminantes despejados pela Capital do Estado do Pará, Belém. A densidade e a diversidade larval foram baixas com forte dominância dos clupeídeos, engraulídeos e, em menor grau, os cianídeos. O principal período de reprodução foi definido no início do período chuvoso. Larvas de Clupeiformes em pré-flexão e flexão foram encontradas nos pontos de coletas mais afastados da cidade, enquanto aquelas em pós-flexão prevaleceram nas margens da cidade. Por outro lado, os cianídeos em pré-flexão e flexão foram capturados perto dos centros de atividade urbana, enquando aqueles em pós-flexão foram pouco abundantes. É sugerido que a baía se encontra na rota migratória dos cianídeos entre a área de desova e os berçários mais distantes. Apesar das águas no entorno da cidade de Belém mostraram sinais de contaminação, a qualidade ambiental na Baía do Guajará no momento do estudo estava apropriada para a vida das larvas de peixes. Nitrato com pH foram as variáveis que melhor explicaram a distribuição larval.

Sugarcane productivity correlated with physical-chemical attributes to create soil management zone

The socioeconomic importance of sugar cane in Brazil is unquestionable because it is the raw material for the production of ethanol and sugar. The accurate spatial intervention in the management of the crop, resulting zones of soil management, increases productivity as well as its agricultural yields. The spatial and Person's correlations between sugarcane attributes and physico-chemical attributes of a Typic Tropustalf were studied in the growing season of 2009, in Suzanápolis, State of São Paulo, Brazil (20°28'10'' S lat.; 50°49'20'' W long.), in order to obtain the one that best correlates with agricultural productivity. Thus, the geostatistical grid with 120 sampling points was installed to soil and data collection in a plot of 14.6 ha with second crop sugarcane. Due to their substantial and excellent linear and spatial correlations with the productivity of the sugarcane, the population of plants and the organic matter content of the soil, by evidencing substantial correlations, linear and spatial, with the productivity of sugarcane, were indicators of management zones strongly attached to such productivity.

The importance of Leptospira interrogans serovars Icterohaemorrhagiae and Canicola in coastal zone and in southern fields of Rio Grande do Sul, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Spatial Variability of CO2 Emissions from Newly Exposed Paraglacial Soils at a Glacier Retreat Zone on King George Island, Maritime Antarctica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chicken hatchlings prefer ambient temperatures lower than their thermoneutral zone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Trichomes related to an unusual method of water retention and protection of the stem apex in an arid zone perennial species

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

CO2 and N2O emissions in a soil chronosequence at a glacier retreat zone in Maritime Antarctica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Does water level affect benthic macro-invertebrates of a marginal lake in a tropical river-reservoir transition zone?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hydrogeology, Chemical Characteristics, and Transport Processes in the Zone of Contribution of a Public-Supply Well in York, Nebraska

In 2001, the U.S. Geological Survey, as part of the National Water Quality Assessment (NAWQA) Program, initiated a topical study of Transport of Anthropogenic and Natural Contaminants (TANC) to PSW (public-supply wells). Local-scale and regional-scale TANC study areas were delineated within selected NAWQA study units for intensive study of processes effecting transport of contaminants to PSWs. This report describes results from a local-scale TANC study area at York, Nebraska, within the High Plains aquifer, including the hydrogeology and geochemistry of a 108-square-kilometer study area that contains the zone of contribution to a PSW selected for study (study PSW), and describes factors controlling the transport of selected anthropogenic and natural contaminants to PSWs.

Landscape-Genetic Analysis of Population Structure in the Texas Gray Fox Oral Rabies Vaccination Zone

In west-central Texas, USA, abatement efforts for the gray fox (Urocyon cinereoargenteus) rabies epizootic illustrate the difficulties inherent in large-scale management of wildlife disease. The rabies epizootic has been managed through a cooperative oral rabies vaccination program (ORV) since 1996. Millions of edible baits containing a rabies vaccine have been distributed annually in a 16-km to 24-km zone around the perimeter of the epizootic, which encompasses a geographic area >4 x 105 km2. The ORV program successfully halted expansion of the epizootic into metropolitan areas but has not achieved the ultimate goal of eradication. Rabies activity in gray fox continues to occur periodically outside the ORV zone, preventing ORV zone contraction and dissipation of the epizootic. We employed a landscape-genetic approach to assess gray fox population structure and dispersal in the affected area, with the aim of assisting rabies management efforts. No unique genetic clusters or population boundaries were detected. Instead, foxes were weakly structured over the entire region in an isolation by distance pattern. Local subpopulations appeared to be genetically non-independent over distances >30 km, implying that long-distance movements or dispersal may have been common in the region. We concluded that gray foxes in west-central Texas have a high potential for long-distance rabies virus trafficking. Thus, a 16-km to 24-km ORV zone may be too narrow to contain the fox rabies epizootic. Continued expansion of the ORV zone, although costly, may be critical to the long-term goal of eliminating the Texas fox rabies virus variant from the United States.

Integrated biomarker responses as environmental status descriptors of a coastal zone (Sao Paulo, Brazil)

Sao Paulo state (Brazil) has one of the most overpopulated coastal zones in South America, where previous studies have already detected sediment and water contamination. However, biological-based monitoring considering signals of xenobiotic exposure and effects are scarce. The present study employed a battery of biomarkers under field conditions to assess the environmental quality of this coastal zone. For this purpose, the activity of CYP 450, antioxidant enzymes, DNA damage, lipid peroxidation and lysosomal membrane were analysed in caged mussels and integrated using Factorial Analysis. A representation of estimated factor scores was performed in order to confirm the factor descriptions characterizing the studied areas. Biomarker responses indicated signals of mussels` impaired health during the monitoring, which pointed to the impact of different sources of contaminants in the water quality and identified critical areas. This integrated approach produced a rapid, sensitive and cost-effective assessment, which could be incorporated as a descriptor of environmental status in future coastal zones biomonitoring. (C) 2011 Elsevier Inc. All rights reserved.

Biological, physical and chemical properties at the Subtropical Shelf Front Zone in the SW Atlantic Continental Shelf

The physical aspects of the Subtropical Shelf Front (STSF) for the Southwest Atlantic Continental Shelf were previously described. However, only scarce data on the biology of the front is available in the literature. The main goal of this paper is to describe the physical, chemical and biological properties of the STSF found in winter 2003 and summer 2004. A cross-section was established at the historically determined location of the STSF. Nine stations were sampled in winter and seven in summer. Each section included a series of conductivity-temperature-depth (CTD) stations where water samples from selected depths were filtered for nutrient determination. Surface samples were taken for chlorophyll a (Chl-a) determination and plankton net tows carried out above and below the pycnocline. Results revealed that winter was marked by an inner-shelf salinity front and that the STSF was located on the mid-shelf The low salinity waters in the inner-shelf indicated a strong influence of freshwater, with high silicate (72 mu M), suspended matter (45 mg l(-1)), phosphate (2.70 mu M) and low nitrate (1.0 mu M) levels. Total dissolved nitrogen was relatively high (22.98 mu M), probably due to the elevated levels of organic compound contribution close to the continental margin. Surface Chl-a concentration decreased from coastal well-mixed waters, where values up to 8.0 mg m(-3) were registered, to offshore waters. Towards the open ocean, high subsurface nutrients values were observed, probably associated to South Atlantic Central Waters (SACW). Zooplankton and ichthyoplankton abundance followed the same trend; three different groups associated to the inner-, mid- and outer-shelf region were identified. During summer, diluted waters extended over the shelf to join the STSF in the upper layer; the concentration of inorganic nutrients decreased in shallow waters; however, high values were observed between 40 and 60 m and in deep offshore waters. Surface Chl-a ranged 0.07-1.5 mg m(-3); winter levels were higher. Three groups of zoo and ichthyoplankton, separated by the STSF, were also identified. Results of the study performed suggest that the influence of freshwater was stronger during winter and that abundance distribution of Chl-a, copepods and ichthyoplankton was related to the Plata Plume Waters (PPW), rather than to the presence of the STSF. During summer, when the presence of freshwater decreases, plankton interactions seem to take place in the STSF. (C) 2008 Elsevier Ltd. All rights reserved.

Changes in subduction in the South Atlantic Ocean during the 21st century in the CCSM3

The Community Climate System Model version 3 is used to analyse changes in water mass subduction rates in the South Atlantic Ocean over the 21st century. The model results are first compared to observations over 1950-2000, and shown to be rather good. The subduction rates do not change significantly over the 21st century, but the densities at which water masses form become significantly lighter. The strong westerly winds in this region do not change much, which suggests small changes to the rate at which the Atlantic sector of the Southern Ocean takes up heat and carbon dioxide over the 21st century.

Ordovician klippen structures of the Sierra de Umango: New insights on Tectonic evolution of the Western Sierras Pampeanas, Argentina

The basement rock of the Pampean flat-slab (Sierras Pampeanas) in the Central Andes was uplifted and rotated in the Cenozoic era. The Western Sierras Pampeanas are characterised by meta-igneous rocks of Grenvillian Mesoproterozoic age and metasedimentary units metamorphosed in the Ordovician period. These rocks, known as the northern Cuyania composite terrane, were derived from Laurentia and accreted toward Western Gondwana during the Early Paleozoic. The Sierra de Umango is the westernmost range of the Western Sierras Pampeanas.This range is bounded by the Devonian sedimentary rocks of the Precordillera on the western side and Tertiary rocks from the Sierra de Maz and Sierra del Espinal on the eastern side and contains igneous and sedimentary rocks outcroppings from the Famatina System on the far eastern side. The Sierra de Umango evolved during a period of polyphase tectonic activity, including an Ordovician collisional event, a Devonian compressional deformation, Late Paleozoic and Mesozoic extensional faulting and sedimentation (Paganzo and Ischigualasto basins) and compressional deformation of the Andean foreland during the Cenozoic. A Nappe System and an important shear zone, La Puntilla-La Falda Shear Zone (PFSZ), characterise the Ordovician collisional event, which was related to the accretion of Cuyania Terrane to the proto-Andean margin of Gondwana. Three continuous deformational phases are recognised for this event: the D1 phase is distinguished by relics of 51 preserved as internal foliation within interkinematic staurolite por-phyroblasts and likely represents the progressive metamorphic stage; the D2 phase exhibits P-T conditions close to the metamorphic peak that were recorded in an 52 transposition or a mylonitic foliation and determine the main structure of Umango; and the D3 phase is described as a set of tight to recumbent folds with S3 axial plane foliation, often related to thrust faults, indicating the retrogressive metamorphic stage. The Nappe System shows a top-to-the S/SW sense direction of movement, and the PFSZ served as a right lateral ramp in the exhumation process. This structural pattern is indicative of an oblique collision, with the Cuyania Terrane subducting under the proto-Andean margin of Gondwana in the NE direction. This continental subduction and exhumation lasted at least 30 million years, nearly the entire Ordovician period, and produced metamorphic conditions of upper amphibolite-to-granulite facies in medium- to high-pressure regimes. At least two later events deformed the earlier structures: D4 and D5 deformational phases. The D4 deformational phase corresponds to upright folding, with wavelengths of approximately 10 km and a general N-S orientation. These folds modified the S2 surface in an approximately cylindrical manner and are associated with exposed, discrete shear zones in the Silurian Guandacolinos Granite. The cylindrical pattern and subhorizontal axis of the D4 folds indicates that the S2 surface was originally flat-lying. The D4 folds are responsible for preserving the basement unit Juchi Orthogneiss synformal klippen. This deformation corresponds to the Chanica Tectonic during the interval between the Devonian and Carboniferous periods. The D5 deformational phase comprehends cuspate-lobate shaped open plunging folds with E W high-angle axes (D5 folds) and sub-vertical spaced cleavage. The D5 folds and related spaced cleavage deformed the previous structures and could be associated with uplifting during the Andean Cycle. (C) 2012 Elsevier Ltd. All rights reserved.