POLYCHAETE ASSEMBLAGE OF AN IMPACTED ESTUARY, GUANABARA BAY, RIO DE JANEIRO, BRAZIL

Thirty-eight stations were sampled in Guanabara Bay, Rio de Janeiro, Brazil, to assess the spatio-temporal diversity and biomass of sublittoral polychaetes. Samples were collected during the dry (September 2000) and rainy season (May 2001) in shallow sublittoral sediments. The polychaete spatial composition showed a heterogeneous distribution throughout the bay. A negative gradient of diversity and biomass was observed towards the inner parts of the bay and sheltered areas. A wide azoic area was found inside the bay. Some high-biomass and low-diversity spots were found near a sewage-discharge point. In these areas, the polychaete biomass increased after the rainy season. A diversified polychaete community was identified around the bay mouth, with no dramatic changes of this pattern between the two sampling periods. Deposit-feeders were dominant in the entire study area. The relative importance of carnivores and omnivores increased towards the outer sector, at stations with coarse sediment fractions. Guanabara Bay can be divided into three main zones with respect to environmental conditions and polychaete diversity and biomass patterns: A) High polychaete diversity, hydrodynamically exposed areas composed of sandy, oxidized or moderately reduced sediments with normoxic conditions in the water column. B) Low diversity and high biomass of deposit and suspension-feeding polychaete species in the middle part of the bay near continental inflows, comprising stations sharing similar proportions of silt, clay and fine sands. C) Azoic area or an impoverished polychaete community in hydrodynamically low-energy areas of silt and clay with extremely reduced sediments, high total organic matter content and hypoxic conditions in the water column, located essentially from the mid-bay towards the north sector. High total organic matter content and hypoxic conditions combined with slow water renewal in the inner bay seemed to play a key role in the polychaete diversity and biomass. Sedimentation processes and organic load coming from untreated sewage into the bay may have negatively affected the survivorship of the fauna.

Integration of spatial and temporal models to predict extreme water table depths

The objective of this work was to evaluate extreme water table depths in a watershed, using methods for geographical spatial data analysis. Groundwater spatio-temporal dynamics was evaluated in an outcrop of the Guarani Aquifer System. Water table depths were estimated from monitoring of water levels in 23 piezometers and time series modeling available from April 2004 to April 2011. For generation of spatial scenarios, geostatistical techniques were used, which incorporated into the prediction ancillary information related to the geomorphological patterns of the watershed, using a digital elevation model. This procedure improved estimates, due to the high correlation between water levels and elevation, and aggregated physical sense to predictions. The scenarios showed differences regarding the extreme levels - too deep or too shallow ones - and can subsidize water planning, efficient water use, and sustainable water management in the watershed.

Pattern of distribution and environmental influences on the Scienidae community of the Southeastern Brazilian coast

The Sciaenids have among the highest species richness, numerical abundance and biomass of any family of fishes along the Brazilian coast. The aim of this study was to analyze the composition and spatial and temporal distribution of as well as the influence of temperature, salinity and depth on the sciaenid assemblage of Santos Bay. A total of 29,306 individuals belonging to 13 genera and 21 species were captured, between November 2004 and December 2005, with Stellifer rastrifer representing 70.4% of the total composition. Highest abundance and biomass occurred on the east side of the bay, and the highest species richness occurred near the mouth of the Santos Channel, which was also the site with least similarity to the other sites. Highest abundances occurred in April 2005 and lowest in September 2005. Key environmental factors influencing distribution of sciaenids were depth and temperature.

Spatial-Temporal Variation in Orchid Bee Communities (Hymenoptera: Apidae) in Remnants of Arboreal Caatinga in the Chapada Diamantina Region, State of Bahia, Brazil

The spatial and temporal distribution of organisms is a fundamental aspect of biological communities. The present study focused on three remnants of arboreal Caatinga in northeastern Brazil between May, 2009 and April, 2010. A total of 627 euglossine males were captured in traps baited with artificial aromatic compounds. The specimens belonged to 14 species and four genera: Euglossa Latreille, Eulaema Lepeletier, Eufriesea Cockerell, and Exaerete Hoffmannsegg. Eulaema nigrita Lepeletier (41.6), Euglossa carolina Nem,sio (15.3%), Eulaema marcii Nem,sio (13.6%), and Euglossa melanotricha Moure (12.8%) were the most common species sampled. The distribution of collected specimens per fragment was as follows: BraA(0)na (280 ha)-259 individuals belonging to 14 species; Cambui (179 ha)-161 individuals from eight species; and Pindoba (100 ha)-207 individuals represented by seven species. BraA(0)na had the highest diversity (H'aEuro parts per thousand= 1.91) and estimated species richness. The largest fragment was the main source of the observed variation in species richness and abundance, indicating a non-random pattern of spatial distribution. The analysis of environmental factors indicated that seasonal variation in these factors was the principal determinant of species occurrence and abundance.

Decisions on Temporal Sampling Protocol Influence the Detection of Ecological Patterns

Within-site variability in species detectability is a problem common to many biodiversity assessments and can strongly bias the results. Such variability can be caused by many factors, including simple counting inaccuracies, which can be solved by increasing sample size, or by temporal changes in species behavior, meaning that the way the temporal sampling protocol is designed is also very important. Here we use the example of mist-netted tropical birds to determine how design decisions in the temporal sampling protocol can alter the data collected and how these changes might affect the detection of ecological patterns, such as the species-area relationship (SAR). Using data from almost 3400 birds captured from 21,000 net-hours at 31 sites in the Brazilian Atlantic Forest, we found that the magnitude of ecological trends remained fairly stable, but the probability of detecting statistically significant ecological patterns varied depending on sampling effort, time of day and season in which sampling was conducted. For example, more species were detected in the wet season, but the SAR was strongest in the dry season. We found that the temporal distribution of sampling effort was more important than its total amount, discovering that similar ecological results could have been obtained with one-third of the total effort, as long as each site had been equally sampled over 2 yr. We discuss that projects with the same sampling effort and spatial design, but with different temporal sampling protocol are likely to report different ecological patterns, which may ultimately lead to inappropriate conservation strategies.

Pattern of distribution and environmental influences on the Scienidae community of the Southeastern Brazilian coast

The Sciaenids have among the highest species richness, numerical abundance and biomass of any family of fishes along the Brazilian coast. The aim of this study was to analyze the composition and spatial and temporal distribution of as well as the influence of temperature, salinity and depth on the sciaenid assemblage of Santos Bay. A total of 29,306 individuals belonging to 13 genera and 21 species were captured, between November 2004 and December 2005, with Stellifer rastrifer representing 70.4% of the total composition. Highest abundance and biomass occurred on the east side of the bay, and the highest species richness occurred near the mouth of the Santos Channel, which was also the site with least similarity to the other sites. Highest abundances occurred in April 2005 and lowest in September 2005. Key environmental factors influencing distribution of sciaenids were depth and temperature.

Life cycle and reproductive traits of marine podonids (Cladocera, Onychopoda) in a coastal subtropical area

We studied the temporal distribution and reproductive biology of marine podonids during two consecutive years off Ubatuba, southeast coast of Brazil. Podonid specimens and their eggs and embryos were counted, measured and classified into categories. Pseudevadne tergestina was the most abundant species, and was more abundant in surface layers, in warm seasons, when the water column was stratified because of bottom intrusions of the cold and nutrient-rich South Atlantic Central Water (SACW) onto the inner shelf. Evadne spinifera had a similar temporal and vertical distribution, but with lower abundance and frequency. Pleopis schmackeri did not show a clear seasonal distribution, but preferred bottom layers. Pleopis polyphemoides and Podon intermedius occurred in low abundances, and only under SACW influence. Parthenogenetic females were dominant among all podonid species. Gamogenetic females of P. polyphemoides and P. intermedius were observed, but males of neither species occurred. This suggests that in tropical and subtropical regions, P. tergestina, E. spinifera and P. schmackeri reproduce through parthenogenesis during most of the year.

Prey-capture efficiency between juveniles and adults, feeding habitat and abundance of Wattled Jacana foragers in northern Pantanal, Mato Grosso state, Brazil

The choice of foraging strategies implies an attempt at gaining energy by predators. Supposedly, the difference in employing the "sit and wait" or "active foraging" behavior lays in hunter skills, experience and the kind of prey consumed. With the hypothesis that "active foraging" demands no learning, in this study we compared the prey capture efficiency among Wattled Jacana juveniles and adults, and also present descriptive information about feeding habitat and the abundance variation of foragers throughout the day in the northern Pantanal. Prey capture efficiency did not differ significantly among juveniles and adults, corroborating our initial hypothesis that "active foraging" is an instinctive behavior and demands no experience to be effective. However, future work is necessary to compare the energetic quality of consumed items by juveniles and adults, searching for differences explained by adults' experience. Foraging individuals were found at an average distance of 14 m ranging from 2 to 42 m) from the margin of the sampled swamps, however 64% of the foragers were found closer to the margins. The average depth of foraging sites was 17 cm, ranging from 5 to 40 cm, although no preference for specific classes of depth was found (p > 0,05). Despite the accepted general pattern of birds being more active in the early morning, the largest number of individuals foraging was observed between 11:00 and 12:00 AM, but no significant difference was found in the abundance of foraging individuals among different periods of the day. Factors, which were not analyzed, such as food availability and presence of competitors and predators need to be studied to reveal the main factors of the spatial and temporal distribution of the Wattled Jacana.

Spatial regimes: dynamics of intentional homicides in the city of Sao Paulo between 2000 and 2008

Objective. To identify the existence of spatial and temporal patterns in the occurrence of intentional homicides in the municipality of Sao Paulo (MSP), Brazil, and to discuss the analytical value of taking such patterns into account when designing studies that address the dynamics and factors associated with the incidence of homicides. Methods. A longitudinal ecological study was conducted, having as units of analysis 13 205 census tracts and the 96 census districts that congregate these sectors in Sao Paulo. All intentional homicides reported in the city between 2000 and 2008 were analyzed. The gross homicide rates per 100 000 population was calculated as well as the global and local Bayesian estimates for each census tract during the study period. To verify the possibility of identifying different patterns of the spatial distribution of homicides, we used BoxMap and Moran's I index. Results. The homicide trends in the city of Sao Paulo in the last decade were not homogeneous and systematic. Instead, seven patterns of spatial distribution were identified; that is, seven spatial regimes for the occurrence of intentional homicides, considering the homicide rates within each census tract as well as the rates in adjacent tracts. These spatial distribution regimes were not contained within the limits of the census tracts and districts. Conclusions. The results show the importance of analyzing the spatial distribution of social phenomena without restriction of political and administrative boundaries.

Dynamical analysis of turbulence in fusion plasmas and nonlinear waves

Turbulence is one of the key problems of classical physics, and it has been the object of intense research in the last decades in a large spectrum of problems involving fluids, plasmas, and waves. In order to review some advances in theoretical and experimental investigations on turbulence a mini-symposium on this subject was organized in the Dynamics Days South America 2010 Conference. The main goal of this mini-symposium was to present recent developments in both fundamental aspects and dynamical analysis of turbulence in nonlinear waves and fusion plasmas. In this paper we present a summary of the works presented at this mini-symposium. Among the questions to be addressed were the onset and control of turbulence and spatio-temporal chaos. (C) 2011 Elsevier B. V. All rights reserved.

Comparison between multiplanar and rendering modes in the assessment of fetal atrioventricular valve areas by 3D/4D ultrasonography

Objective: To compare the agreement of multiplanar and rendering modes in the assessment fetal atrioventricular valves (mitral and tricuspid) areas by three-dimensional (3D) ultrasonography using the software spatio-temporal image correlation (STIC). Methods: We conducted a prospective cross-sectional study with normal pregnant women, with single fetuses, between 18-33 weeks. To measure the areas, we used the plan of four-chamber view. In the case of multiplanar, the plane was rotated on the axis "Z" form the heart to position at 9h. For rendering, the green line (region of interest - ROI) was placed from the atria of the heart perpendicular to the crux. The agreement was assessed by a Bland-Altman (limits of agreement) using the relative difference between the measures: ((rendering mode) - (multiplanar mode)) / (average). Results: 328 fetuses were evaluated. We have not identified the occurrence of systematic error between methods: the average relative difference was 1.62% (-2.07% to 5.32%, confidence interval 95%) in the mitral and 1.77% (- 1.08% to 4.62%) in the tricuspid valve. The limits of agreement between methods were -65.26% to 68.51% for the mitral and -49.91% to 53.45% for the tricuspid. Conclusions: There was no systematic error between modes and thus the observed values for the area of fetal atrioventricular valves can be used for comparisons needs to be corrected. However, relatively large variations may be observed when repeating the measurement area by different modes.

Changes in intrapopulation resource use patterns of an endangered raptor in response to a disease-mediated crash in prey abundance

1. A long-standing question in ecology is how natural populations respond to a changing environment. Emergent optimal foraging theory-based models for individual variation go beyond the population level and predict how its individuals would respond to disturbances that produce changes in resource availability. 2. Evaluating variations in resource use patterns at the intrapopulation level in wild populations under changing environmental conditions would allow to further advance in the research on foraging ecology and evolution by gaining a better idea of the underlying mechanisms explaining trophic diversity. 3. In this study, we use a large spatio-temporal scale data set (western continental Europe, 19682006) on the diet of Bonellis Eagle Aquila fasciata breeding pairs to analyse the predator trophic responses at the intrapopulation level to a prey population crash. In particular, we borrow metrics from studies on network structure and intrapopulation variation to understand how an emerging infectious disease [the rabbit haemorrhagic disease (RHD)] that caused the density of the eagles primary prey (rabbit Oryctolagus cuniculus) to dramatically drop across Europe impacted on resource use patterns of this endangered raptor. 4. Following the major RHD outbreak, substantial changes in Bonellis Eagles diet diversity and organisation patterns at the intrapopulation level took place. Dietary variation among breeding pairs was larger after than before the outbreak. Before RHD, there were no clusters of pairs with similar diets, but significant clustering emerged after RHD. Moreover, diets at the pair level presented a nested pattern before RHD, but not after. 5. Here, we reveal how intrapopulation patterns of resource use can quantitatively and qualitatively vary, given drastic changes in resource availability. 6. For the first time, we show that a pathogen of a prey species can indirectly impact the intrapopulation patterns of resource use of an endangered predator.

Giant magnetofossils and hyperthermal events

Magnetotactic bacteria biomineralize magnetic minerals with precisely controlled size, morphology, and stoichiometry. These cosmopolitan bacteria are widely observed in aquatic environments. If preserved after burial, the inorganic remains of magnetotactic bacteria act as magnetofossils that record ancient geomagnetic field variations. They also have potential to provide paleoenvironmental information. In contrast to conventional magnetofossils, giant magnetofossils (most likely produced by eukaryotic organisms) have only been reported once before from Paleocene-Eocene Thermal Maximum (PETM; 55.8 Ma) sediments on the New Jersey coastal plain. Here, using transmission electron microscopic observations, we present evidence for abundant giant magnetofossils, including previously reported elongated prisms and spindles, and new giant bullet-shaped magnetite crystals, in the Southern Ocean near Antarctica, not only during the PETM, but also shortly before and after the PETM. Moreover, we have discovered giant bullet-shaped magnetite crystals from the equatorial Indian Ocean during the Mid-Eocene Climatic Optimum (similar to 40 Ma). Our results indicate a more widespread geographic, environmental, and temporal distribution of giant magnetofossils in the geological record with a link to "hyperthermal" events. Enhanced global weathering during hyperthermals, and expanded suboxic diagenetic environments, probably provided more bioavailable iron that enabled biomineralization of giant magnetofossils. Our micromagnetic modelling indicates the presence of magnetic multi-domain (i.e., not ideal for navigation) and single domain (i.e., ideal for navigation) structures in the giant magnetite particles depending on their size, morphology and spatial arrangement. Different giant magnetite crystal morphologies appear to have had different biological functions, including magnetotaxis and other non-navigational purposes. Our observations suggest that hyperthermals provided ideal conditions for giant magnetofossils, and that these organisms were globally distributed. Much more work is needed to understand the interplay between magnetofossil morphology, climate, nutrient availability, and environmental variability.

Terrestrial non-volant small mammals in agro-silvicultural landscapes of Southeastern Brazil

The area covered by Eucalyptus plantations is significantly increasing in Brazil for economic reasons. However, the impact of such land use change is still unknown. In this study we evaluated the spatial-temporal distribution and abundance of terrestrial non-volant small mammals on a recently converted landscape whose matrix is formed by Eucalyptus plantations up to 3 years of age. From August 2007 to July 2009 we carried out monthly sampling campaigns over a grid of 30 sampling units, formed by pitfall traps covering both the landscape matrix of Eucalyptus plantations (n = 18) and legal conservation areas of native vegetation (n = 7) and abandoned pastures (n = 5). A total of 1640 individuals from 14 species of the orders Didelphimorphia (4 spp.) and Rodentia (10 spp.) were captured. However, only three species of rodents (Olygorysomys flavescens, Oligoryzomys nigripes and Calomy tener) represented 81.8% of the total amount. Eucalyptus plantations had a lower species richness and abundance than the abandoned pasture and the remaining fragments of native vegetation. Although the present species are predominantly generalists, there is clear distinction among environments in terms of their species composition and relative abundance, which also present a pronounced time variation. The assemblage found in this study suggests that silvicultural landscapes still have some conservation value, with species that seem to be resident at the Eucalyptus plantations. Moreover, the presence of the native and abandoned pastures patches imbibed in the Eucalyptus plantation matrix may increase the carrying capacity of such a silvicultural system and these landscapes may play a role in maintaining local biodiversity. (C) 2012 Elsevier B.V. All rights reserved.

Sero-epidemiological evaluation of changes in Plasmodium falciparum and Plasmodium vivax transmission patterns over the rainy season in Cambodia

Background: In Cambodia, malaria transmission is low and most cases occur in forested areas. Seroepidemiological techniques can be used to identify both areas of ongoing transmission and high-risk groups to be targeted by control interventions. This study utilizes repeated cross-sectional data to assess the risk of being malaria sero-positive at two consecutive time points during the rainy season and investigates who is most likely to sero-convert over the transmission season. Methods: In 2005, two cross-sectional surveys, one in the middle and the other at the end of the malaria transmission season, were carried out in two ecologically distinct regions in Cambodia. Parasitological and serological data were collected in four districts. Antibodies to Plasmodium falciparum Glutamate Rich Protein (GLURP) and Plasmodium vivax Merozoite Surface Protein-119 (MSP-119) were detected using Enzyme Linked Immunosorbent Assay (ELISA). The force of infection was estimated using a simple catalytic model fitted using maximum likelihood methods. Risks for sero-converting during the rainy season were analysed using the Classification and Regression Tree (CART) method. Results: A total of 804 individuals participating in both surveys were analysed. The overall parasite prevalence was low (4.6% and 2.0% for P. falciparum and 7.9% and 6.0% for P. vivax in August and November respectively). P. falciparum force of infection was higher in the eastern region and increased between August and November, whilst P. vivax force of infection was higher in the western region and remained similar in both surveys. In the western region, malaria transmission changed very little across the season (for both species). CART analysis for P. falciparum in the east highlighted age, ethnicity, village of residence and forest work as important predictors for malaria exposure during the rainy season. Adults were more likely to increase their antibody responses to P. falciparum during the transmission season than children, whilst members of the Charay ethnic group demonstrated the largest increases. Discussion: In areas of low transmission intensity, such as in Cambodia, the analysis of longitudinal serological data enables a sensitive evaluation of transmission dynamics. Consecutive serological surveys allow an insight into spatio-temporal patterns of malaria transmission. The use of CART enabled multiple interactions to be accounted for simultaneously and permitted risk factors for exposure to be clearly identified.