Analysis of the kinetics of phase and amplitude gratings recorded in azopolymer films

In this work we use a stabilized holographic technique to study both refractive index and absorption gratings recorded in thin films made of Disperse Red 1 (DR1) embedded in an organic polymer matrix (PMMA) deposited on glass substrate. Gratings are recorded by linearly polarized illumination with the interference pattern of two crossing beams. One of the beams is phase modulated and the interference signals between the transmitted and diffracted waves are detected by a tuned lock-in amplifier. The technique allows measuring separately changes of the refractive index and the absorption coefficient during the course of the photoreaction process. The time evolution of the diffraction efficiencies during recording has shown bi-exponential kinetics for both gratings. © 2008 American Institute of Physics.

Spatial and temporal distribution of the shrimp nematopalaemon schmitti (Decapoda: Caridea: Palaemonidae) at a subtropical enclosed bay in South America

The spatio-temporal distribution of the soft bottom dwelling shrimp Nematopalaemon schmitti and the effect of environmental conditions (sediment characteristics, temperature, salinity and dissolved oxygen) on its abundance were studied at Ubatuba Bay, south-eastern coast of Brazil. Surveys were conducted monthly from September 1995 to August 1996. Each sampling set comprised eight different transects distributed within the bay. Comparisons of CPUE of shrimp among sampling stations demonstrated that the abundance of N. schmitti was the greatest during winter, when average water temperature within the bay was considerably lower than during the rest of the year. Most shrimps (more than 95%) were collected at a single transect located at the northernmost side of the bay, demonstrating the extremely patchy distribution of this species. A multiple regression analysis using data only from this northernmost transect indicated that temperature was the most relevant factor affecting the abundance of N. schmitti during the year. Copyright © 2009 Marine Biological Association of the United Kingdom.

Spatial and temporal variability in soil CO2-C emissions and relation to soil temperature at King George Island, maritime Antarctica

Few studies have examined the effects of temperature on spatial and temporal trends in soil CO2-C emissions in Antarctica. In this work, we present in situ measurements of CO2-C emissions and assess their relation with soil temperature, using dynamic chambers. We found an exponential relation between CO2 emissions and soil temperature, with the value of Q10 being close to 2.1. Mean emission rates were as low as 0.026 and 0.072 g of CO2-C m-2 h-1 for bare soil and soil covered with moss, respectively, and as high as 0.162 g of CO2-C m-2 h-1 for soil covered with grass, Deschampsia antarctica Desv. (Poaceae). A spatial variability analysis conducted using a 60-point grid, for an area with mosses (Sannionia uncianata) and D. antarctica, yielded a spherical semivariogram model for CO2-C emissions with a range of 1 m. The results suggest that soil temperature is a controlling factor on temporal variations in soil CO2-C emissions, although spatial variations appear to be more strongly related to the distribution of vegetation types. © 2010 Elsevier B.V. and NIPR.

Spatial and seasonal patterns in fish assemblage in Córrego Rico, upper Paraná river Basin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spatial and temporal distribution in density and biomass of two Pseudodiaptomus species (Copepoda: Calanoida) in the Caeté river estuary (Amazon region - North of Brazil)

A distribuição espacial e temporal da densidade e biomassa dos copépodos planctônicos Pseudodiaptomus richardi e P. acutus, ao longo de um gradiente de salinidade, foi estudada no Estuário do Rio Caeté (Norte do Brasil) durante os meses de junho e dezembro de 1998 (estação seca) e fevereiro e maio de 1999 (estação chuvosa). A biomassa dos copépodos foi estimada a partir de parâmetros da regressão baseada na relação entre o peso seco e o comprimento do corpo (prossoma) de organismos adultos. O Estuário do Rio Caeté caracterizou-se por uma grande variação espacial e sazonal na salinidade (0,8-37,2). A relação peso-comprimento para ambas as espécies de Pseudodiaptomus foi do tipo exponencial. Os valores de densidade e biomassa oscilaram entre 0,28-46,18 ind. m^-3 e 0,0022-0,3507 mg DW. m^-3 para P. richardi; e entre 0,01-17,02 ind. m^-3 e 0,0005-0,7181 mg DW. m^-3 para P. acutus. Os resultados revelaram que a contribuição de P. richardi para a produção secundária no Estuário do Rio Caeté é mais importante na zona liminética que em outras zonas onde foram dominantes os regimes eurihalino-polihalino. Contudo, para P. acutus não foi possível observar de forma clara um padrão de distribuição espacial e temporal para a área estudada.

A Spatial and Temporal Prediction Model of Corn Grain Yield as a Function of Soil Attributes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The influence of landscape on the spatial and temporal distribution of stream macroalgal communities of two types of subtropical biomes

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

LONG-TERM PATTERNS OF SPATIAL AND TEMPORAL DISTRIBUTION IN THE SEABOB SHRIMP XIPHOPENAEUS KROYERI (DECAPODA: PENAEIDAE) POPULATION IN SOUTHEASTERN BRAZIL

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Temporal, spatial and spatiotemporal analysis of the occurrence of visceral leishmaniasis in humans in the City of Birigui, State of São Paulo, from 1999 to 2012

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

On the spatial and temporal dependence of CO2 emission on soil properties in sugarcane (Saccharum spp.) production

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Community-wide spatial and temporal discordances of seed-seedling shadows in a tropical rainforest

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

Road-kills of the giant anteater in south-eastern Brazil: 10 years monitoring spatial and temporal determinants

Context. The giant anteater, Myrmecophaga tridactyla, is a large insectivorous mammal from Cerrado which is classified as vulnerable by the IUCN's red list. In spite of frequent giant anteater casualties, there continues to be a lack of published data on how road and landscape attributes affect road-kill rates - information that could prove useful in guiding mitigation measures.Aims. We seek to determine whether road and landscape attributes influence the incidence of road-kills of the giant anteater.Methods. From February 2002 to December 2012 (except for 2004), five roads in two regions in south-eastern Brazil were surveyed twice each month by car. We recorded temporal road-kill data for the giant anteater and related spatial road variables. These variables were also recorded at regular control sites every 2 km. We also took traffic volume data on stretches of the two roads to correlate with road-kills.Key results. Of the 45 anteater casualties recorded, there was a predominance of adult males. On roads MG-428 and SP-334, we found anteater road-kills were more common in the dry season, negatively correlated with traffic volume and related to the presence of native vegetation. Accordingly, road-kill sites tended to occur near the cerrado and grasslands and also appeared more frequently on some straight stretches of roadways. Although it was not shown to influence road-kill rates, topography data does point to regular overpass/underpass locations allowing population connectivity. Termitaria or ant nests were present at all road-kill sites, with 86% having signs of feeding.Conclusions. Native vegetation along roadways, together with straight road design, increases the probability of anteater road-kills by 40.1%.Implications. For mitigation, mowing and removing insect nests on roadsides, as well as roadside wildlife fencing in cerrado and grassland areas is suggested. Warning signs and radar to reduce vehicle speed are recommended for both human safety and anteater conservation. With regard to population connectivity, the absence of aggregated anteater road-kill data in this study meant that there were no particular crossing locations identified. However, the collected topography data do show places that could be used for roadway crossings. The measures indicated may apply to similar species and types of topography on other continents.

Congruent spatial and temporal foraging by a dominant ant (Hym., Formicidae) and its replacement in an assemblage in a large urban structure in southeastern Brazil

At fixed bail stations in a large institutional setting in Brazil, the temporal and spatial pattern of usage of the dominant species of ant was studied. The ant Crematogaster cf. magnifica, was found in 91% of sampling points. These studies were conducted using the same points as a previous study of tile then dominant ant. Monomorium pharaonis, which was found to have declined from 93% to 3% spatial point occupation. The frequency of point usage during this study was significantly different from the Poisson distribution for both species, indicating non-random use of space. Crematogaster cf. magnifica was significantly more spatially exclusive than had been documented for M. pharaonis, and the probability of points originally occupied by M. pharaonis later becoming occupied by C. cf. magnifica was in excess of 90%. Temporal bait exploitation patterns of the two species did not differ. These data demonstrate that structural ant communities can change over time without human intervention, although short- term stability is characteristic of the urban dominant ants in subtropical Brazil.

Spatial and temporal quality of water in the Itupararanga Reservoir, Alto Sorocaba basin (SP), Brazil

Considering the great importance of the Itupararanga Reservoir, Upper Alto Sorocaba basin/SP, this study aimed to report the variations of some parameters of water quality in the spatial and temporal gradients in this multipurpose res- ervoir. The eutrophication of this reservoir was checked using the Carlson Index Modified and the results indicate that the surface water were classified as eutrophic and mesotrophic in wet and dry periods, being characterized the better quality of water in wet period. In the vertical gradient the results showed a stratiphication in all parameters analyzed, except for the electrical conductivity, with good correlation between total phosphorous and chlorophyll-a, indicating that eutrophication of the reservoir changes the conditions of algal growth, mainly in its initial area. Immediate inter- ventions are needed, which must be directed to planning of land use, domestic effluents treatment, taking to an inte- grated management of this important watershed located in the São Paulo State.

Starch accumulation in cassava roots: spatial and temporal distribution

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)