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BACKGROUND: We analyse the distribution of Gastropods and Chitons from shallow to deep waters along the southwestern Atlantic Ocean off Argentina and discuss possible factors determining the observed biogeographic patterns. RESULTS: Three major biogeographic groups are defined on the basis of Gastropod and Chiton species associations, i.e., continental shelf (< 350 m), upper continental slope (> 350-2000 m) and lower continental slope (2000-3000 m). Bathymetry appears as the main factor modifying large-scale distribution of the fauna at a. In this scenario, species associations are determined by marine currents that clearly occur at a particular and well defined depth. No arrangement of species by geographic location was found in assemblages from the continental shelf and upper continental slope. CONCLUSIONS: We hypothesize that depth and marine currents are the main factor affecting the distribution of Gastropods and Chitons along the SW Atlantic between 200 and 3000 m depth.

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A computational system consisting of an urban mobility simulator, validated fluid dynamics and an integral exposure model, is proposed to obtain cyclist and pedestrian exposure to PMx and NOx. Pedestrian activities in the urban anthroposphere include walking and running. The computational experiments take place in a computer-generated urban canyon, subject to emissions from diesel and gasoline Euro 5 and Euro 6 vehicular technologies, in continuous and stop-and-go traffic scenarios, and three wind directions at two speeds. The exposure time in the computational domain of slow and fast pedestrians were obtained. Slow pedestrians had exposure times around 17% more than fast pedestrians due to their higher sidewalk residence time. Runners and cyclists decreased their exposures by 57% and 73% respectively compared with walkers. Two traffic scenarios are implemented: one due the presence of a hump and another without a hump. The presence of the hump, increased exposure and fuel consumption by 60% per heavy duty vehicle, about 44-48% per light duty vehicle and about 54-71% per passenger car. Vehicular technology had a large influence on exposure: Heavy duty-Euro 6 vehicle decreased 86% the exposure to PM2.5 and 66% to NOX with respect to Euro 5. The proposed computational system provides information on how wind velocity influenced the inhomogeneous pollutant distribution in the street-canyon, causing exposure to be dependent on pedestrian route location. Microscale sidewalk areas in the order of meters containing higher concentrations were thus located. The cleanest routes in the urban canyon were identified. When the wind intensity doubled from 2 to 4 m s-1, exposure concentration decreased around 45%. The proposed system provides a computational platform to study urban atmospheric fluids, scenarios such as pedestrian routes, vehicular technologies, traffic velocities, meteorological conditions and urban morphology affecting pollution exposure.

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The state of Hidalgo (Mexico) is an important region from the point of view of biodiversity. However, there exists a significant gap in accessible knowledge about species diversity and distribution, especially regarding to freshwater ecosystems. This dataset comprises the sampling records of two projects developed in Hidalgo between 2007 and 2009 about the freshwater fish communities of Tecocomulco lake and rivers belonging to the Metztitlán Canyon Biosphere Reserve. It contains the taxonomic identity (species level) and basic biometric data (total length and weight) as well as date of collection and coordinates of more than 9000 specimens. This dataset is the primary result of the first and unrepeated exhaustive freshwater fish's survey of Metztitlán Canyon Biosphere Reserve and Tecocomulco lake. It incorporates seven more species to the regional fish fauna, and new exclusive biometric data of ten species. This dataset can be used by studies dealing with, among other interests, North American freshwater fish diversity (species richness, distribution patterns) and biometric analyses, useful for the management and conservation of these areas. The complete dataset is also provided in Darwin Core Archive format.

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O aumento da frota veicular causa a deterioração da qualidade do ar e o comprometimento da saúde e bem-estar da população. A malha urbana edificada influencia o escoamento do ar, dificultando a dispersão de emissões veiculares. O presente estudo objetiva avaliar a influência dos parâmetros de ocupação do solo definidos pela legislação municipal nos eixos estruturais em Curitiba (PR), caracterizados pelo forte estímulo ao adensamento e alto tráfego veicular. Foram simuladas variações do recuo frontal e das alturas das edificações nestes eixos, em especial na Avenida Sete de Setembro, a fim de verificar a influência destes na concentração de poluentes. São feitas sugestões de possíveis alterações à legislação em vigor, recomendando-se reduzir a altura das edificações no lado oposto ao vento predominante e aumentar, nos trechos não consolidados, o recuo frontal da sobreloja.

The increase in the number of vehicles causes deterioration of air quality and decline of population health and well-being. The urban grid of buildings influences air flow, hampering the dispersion of vehicular emissions. The present study aims to assess the influence of land use parameters defined by local legislation, at the Structural Axes in Curitiba (PR), which are characterized by strong stimulus both to high urban density and vehicular traffic. Variations in building setback front line and height were considered, specifically on Avenida Sete de Setembro, in order to investigate their influence on pollutant concentration. The conclusion includes suggestions for modifications in the current city by-laws of land use, recommending that building height be reduced on the side opposite to prevailing winds, and increasing, in yet not consolidated stretches, the frontal setback of mezzanines.