Chlorinated pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons in the fat tissue of seabirds from King George Island, Antarctica

Antarctic Brazilian Program (PROANTAR)

Arsenic and trace metal contents in sediment profiles from the Admiralty Bay, King George Island, Antarctica

Admiralty Bay (Antarctica) hosts three scientific stations (Ferraz, Arctowski and Macchu Picchu), which require the use of fossil fuel as an energy source. Fossil fuels are also considered the main source of pollution in the area, representing important inputs of major pollutants (organic compounds) and trace metals and metalloids of environmental interest. Accordingly, this work presents the results of As, Cd, Cr, Cu, Ni, Pb and Zn in sediment profiles from Admiralty Bay. The sediment results from Ferraz station were slightly higher than the other sampling sites. The highest contents were observed for Cu and Zn (from 44 to 89 mg kg(-1)). Otherwise, by using enrichment factors and geochronology analysis, the most relevant enrichment was observed for As in the samples collected close to the Ferraz station, indicating that increasing As content may be associated with the activities associated with this site. Published by Elsevier Ltd.

Revealing archaeal diversity patterns and methane fluxes in Admiralty Bay, King George Island, and their association to Brazilian Antarctic Station activities

The study of Antarctic archaeal communities adds information on the biogeography of this group and helps understanding the dynamics of biogenic methane production in such extreme habitats. Molecular methods were combined to methane flux determinations in Martel Inlet, Admiralty Bay, to assess archaeal diversity, to obtain information about contribution of the area to atmospheric methane budget and to detect possible interferences of the Antarctic Brazilian Station Comandante Ferraz (EACF) wastewater discharge on local archaeal communities and methane emissions. Methane fluxes in Martel Inlet ranged from 3.2 to 117.9 mu mol CH(4) m(-2) d(-1), with an average of 51.3 +/- 8.5 mu mol CH(4) m(-2) d(-1) and a median of 57.6 mu mol CH(4) m(-2)d(-1). However, three negative fluxes averaging -11.3 mu mol CH(4) m(-2) d(-1) were detected in MacKellar Inlet, indicating that Admiralty Bay can be either a source or sink of atmospheric methane. Denaturing gradient gel electrophoresis (DGGE) showed that archaeal communities at EACF varied with depth and formed a group separated from the reference sites. Granulometric analysis indicated that differences observed may be mostly related to sediment type. However, an influence of wastewater input could not be discarded, since higher methane fluxes were found at CF site. suggesting stimulation of local methanogenesis. DGGE profile of the wastewater sample grouped separated from all other samples, suggesting that methanogenesis stimulation may be due to changes in environmental conditions rather than to the input of allochtonous species from the wastewater. 16S ribosomal DNA clone libraries analysis showed that all wastewater sequences were related to known methanogenic groups belonging to the hydrogenotrophic genera Methanobacterium and Methanobrevibacter and the aceticlastic genus Methanosaeta. EACF and Botany Point sediment clone libraries retrieved only groups of uncultivated Archaea, with predominance of Crenarchaeota representatives (MCG, MG1, MBG-B, MBG-C and MHVG groups). Euryarchaeota sequences found were mostly related to the LDS and RC-V groups, but MBG-D and DHVE-5 were also present. No representatives of cultivated methanogenic groups were found, but coverage estimates suggest that a higher number of clones would have to be analyzed in order to cover the greater archaeal diversity of Martel Inlet sediment. Nevertheless, the analysis of the libraries revealed groups not commonly found by other authors in Antarctic habitats and also indicated the presence of groups of uncultivated archaea previously associated to methane rich environments or to the methane cycle. (C) 2010 Elsevier Ltd. All rights reserved.

Results from a 15-year study on hydrocarbon concentrations in water and sediment from Admiralty Bay, King George Island, Antarctica

Admiralty Bay on the King George Island hosts the Brazilian, Polish and Peruvian research stations as well as the American and Ecuadorian field stations. Human activities in this region require the use of fossil fuels as an energy source, thereby placing the region at risk of hydrocarbon contamination. Hydrocarbon monitoring was conducted on water and sediment samples from the bay over 15 years. Fluorescence spectroscopy was used for the analysis of total polycyclic aromatic hydrocarbons (PAHs) in seawater samples and gas chromatography with flame ionization and/or mass spectrometric detection was used to analyse individual n-alkanes and PAHs in sediment samples. The results revealed that most sites contaminated by these Compounds are around the Brazilian and Polish research stations due to the intense human activities, mainly during the summer. Moreover, the sediments revealed the presence of hydrocarbons from different sources, suggesting a mixture of the direct input of oil or derivatives and derived from hydrocarbon combustion. A decrease in PAH concentrations occurred following improvement of the sewage treatment facilities at the Brazilian research station, indicating that the contribution from human waste may be significant.

Into the Island: A new technique of non-invasive cortical stimulation of the insula

Study aim. - We describe a new neuronavigation-guided technique to target the posterior-superior insula (PSI) using a cooled-double-cone coil for deep cortical stimulation. Introduction. - Despite the analgesic effects brought about by repetitive transcranial magnetic stimulation (TMS) to the primary motor and prefrontal cortices, a significant proportion of patients remain symptomatic. This encouraged the search for new targets that may provide stronger pain relief. There is growing evidence that the posterior insula is implicated in the integration of painful stimuli in different pain syndromes and in homeostatic thermal integration. Methods. - The primary motor cortex representation of the lower leg was used to calculate the motor threshold and thus, estimate the intensity of PSI stimulation. Results. - Seven healthy volunteers were stimulated at 10 Hz to the right PSI and showed subjective changes in cold perception. The technique was safe and well tolerated. Conclusions. - The right posterior-superior insula is worth being considered in future studies as a possible target for rTMS stimulation in chronic pain patients. (c) 2012 Elsevier Masson SAS. All rights reserved.

JUVENILE RECRUITMENT, EARLY GROWTH, AND MORPHOLOGICAL VARIATION IN THE ENDANGERED SANTA CATALINA ISLAND RATTLESNAKE, CROTALUS CATALINENSIS

Life-history information constitutes the raw data for building population models used in species conservation. We provide life-history data for the endangered Santa Catalina Island Rattlesnake, Crotalus catalinensis. We use data from 277 observations of C. catalinensis made between 2002 and 2011 on the island. Mean snout-vent length (SVL) of adult C. catalinensis was 643 mm for males and 631 mm for females; the difference was not significant. The degree of sexual size dimorphism (SSD; using SVL) was -0.02. However, sexes were dimorphic in total length ( SVL + tail length), relative tail length, and stoutness. Juvenile recruitment occurs during late-summer. In their first year of life, juveniles seem to grow at a rate of about 1.7 cm/mo. Females seem to become mature around 570 mm SVL, probably in the year when they become 2 y old. Scattered literature data corroborates the time of juvenile recruitment described herein. Growth in C. catalinensis seems to be slower than that of C. ruber, its sister taxa, but similar to other rattlesnakes.

Genome Sequence of Exiguobacterium antarcticum B7, Isolated from a Biofilm in Ginger Lake, King George Island, Antarctica

Exiguobacterium antarcticum is a psychotropic bacterium isolated for the first time from microbial mats of Lake Fryxell in Antarctica. Many organisms of the genus Exiguobacterium are extremophiles and have properties of biotechnological interest, e. g., the capacity to adapt to cold, which make this genus a target for discovering new enzymes, such as lipases and proteases, in addition to improving our understanding of the mechanisms of adaptation and survival at low temperatures. This study presents the genome of E. antarcticum B7, isolated from a biofilm sample of Ginger Lake on King George Island, Antarctic peninsula.

The golden lancehead Bothrops insularis (Serpentes: Viperidae) relies on two seasonally plentiful bird species visiting its island habitat

Adult individuals of the island pitviper Bothrops insularis have a diet based on birds. We analysed bird species recorded in the gut of this snake and found that it relies on two out of 41 bird species recorded on the island. When present, these two prey species were among the most abundant passerine birds on the island. A few other migrant birds were very occasionally recorded as prey. A resident bird species (Troglodytes musculus) is the most abundant passerine on the island, but seems able to avoid predation by the viper. Bothrops insularis is most commonly found on the ground. However, during the abundance peak of the tyrannid passerine Elaenia chilensis on the island, more snakes were found on vegetation than on the ground. We suggest that one cause may be that these birds forage mostly on vegetation, and thus cause the snakes to search for prey on this arboreal substratum.

Nuculidae (Bivalvia) in the Cape Melville Formation, King George Island, Antarctica, with an overview of the bivalve fauna

Nuculid bivalves of the Cape Melville Formation (Early Miocene, King George Island) are reviewed. Ten bivalve taxa are listed from the formation in the families Nuculidae (two species), Sareptidae, Malletiidae, Limopsidae (two species), Limidae, Pectinidae, Hiatellidae, and Periplomatidae. The Nuculidae consist of two species of Leionucula Quenstedt, 1930. One of these, L. melvilleana n. sp., is described and the other consists of the two species named previously by Anelli et al. (2006), which are demonstrated to be synonymous and are assigned to the species Leionucula frigida (Anelli, Rocha-Campos, Santos, Perinotto & Quaglio 2006). This assemblage, dominated by protobranchs (89% of specimens), is a typical fauna of offshore soft substrates, with a few specimens transported from hard substrates nearby. The diversity of Nuculidae has decreased in the Antarctic region through the Cenozoic.

NATURAL REGENERATION IN ABANDONED FIELDS FOLLOWING INTENSIVE AGRICULTURAL LAND USE IN AN ATLANTIC FOREST ISLAND, BRAZIL

The time required to regrowth a forest in degraded areas depends on how the forest is removed and on the type of land use following removal. Natural regeneration was studied in abandoned old fields after intensive agricultural land use in areas originally covered by Brazilian Atlantic Forests of the Anchieta Island, Brazil in order to understand how plant communities reassemble following human disturbances as well as to determine suitable strategies of forest restoration. The fields were classified into three vegetation types according to the dominant plant species in: 1) Miconia albicans (Sw.) Triana (Melastomataceae) fields, 2) Dicranopteris flexuosa (Schrader) Underw. (Gleicheniaceae) thickets, and 3) Gleichenella pectinata (Willd.) Ching. (Gleicheniaceae) thickets. Both composition and structure of natural regeneration were compared among the three dominant vegetation types by establishing randomly three plots of 1 x 3 m in five sites of the island. A gradient in composition and abundance of species in natural regeneration could be observed along vegetation types from Dicranopteris fern thickets to Miconia fields. The gradient did not accurately follow the pattern of spatial distribution of the three dominant vegetation types in the island regarding their proximity of the remnant forests. A complex association of biotic and abiotic factors seems to be affecting the seedling recruitment and establishment in the study plots. The lowest plant regeneration found in Dicranopteris and Gleichenella thickets suggests that the ferns inhibit the recruitment of woody and herbaceous species. Otherwise, we could not distinguish different patterns of tree regeneration among the three vegetation types. Our results showed that forest recovery following severe anthropogenic disturbances is not direct, predictable or even achievable on its own. Appropriated actions and methods such as fern removal, planting ground covers, and enrichment planting with tree species were suggested in order to restore the natural forest regeneration process in the abandoned old fields.

Condom use at last sexual relationship among adolescents of Santiago Island, Cape Verde, - West Africa

Objective: To estimate factors associated with condom use at last sexual intercourse among adolescents. Methods: Cross-sectional study of a representative sample of 368 sexually active adolescents aged 13-17 years from eight public high schools on Santiago Island, Cape Verde, 2007. The level of significance was 5.0% obtained from logistic regression, considering the association between condom use and socio-demographic, sexual and reproductive variables. Results: The prevalence of condom use at last sexual intercourse was 94.9%. Factors associated with condom use at last sexual relationship were: non-Catholic religion (OR=0.68, 95%CI: 0.52; 0.88) and affective-sexual partnership before the interview (OR=5.15, 95%CI: 1.79; 14.80). Conclusions: There was a high prevalence of condom use at last sexual intercourse of adolescents.

The last mangroves of Marajo Island - Eastern Amazon: Impact of climate and/or relative sea-level changes

The dynamics, over the last 7500 years, of a mangrove at Marajo Island in northern Brazil were studied by pollen and sedimentary facies analyses using sediment cores. This island, located at the mouth of the Amazon River. is influenced by riverine inflow combined with tidal fluctuations of the equatorial Atlantic Ocean. Herbaceous vegetation intermingled with rainforest dominates the central area of the island, while varzea is the main vegetation type along the littoral. In particular, the modem northeastern coastal zone is covered by a mosaic of dense rainforest, herbaceous vegetation, mangroves, varzea, and restinga. The integration of pollen data and fades descriptions indicates a tidal mud flat colonized by mangroves in the interior of Marajo Island between similar to 7500 cal yr BP and similar to 3200 cal yr BP. During the late Holocene, mangroves retracted to a small area (100-700 m in width) along the northeastern coastal plain. Mangrove expansion during the early and mid Holocene was likely caused by the post-glacial sea-level rise which, combined with tectonic subsidence, led to a rise in tidal water salinity. Salinity must have further increased due to low river discharge resulting from increased aridity during the early and mid Holocene. The shrinking of the area covered by mangrove vegetation during the late Holocene was likely caused by the increase in river discharge during the late Holocene, which has maintained relatively low tidal water salinity in Marajo Island. Tidal water salinity is relatively higher in the northeastern part of the island than in others, due to the southeast-northwest trending current along the littoral. The mixing of marine and riverine freshwater inflows has provided a refuge for mangroves in this area. The increase in flow energy during the last century is related to landward sand migration, which explains the current retraction of mangroves. These changes may indicate an increased exposure to tidal influence driven by the relative sea-level rise, either associated with global fluctuations or tectonic subsidence, and/or by an increase in river water discharge. (C) 2012 Elsevier B.V. All rights reserved.

The Panama microplate, island studies and relictual species of Melipona (Melikerria) (Hymenoptera: Apidae: Meliponini)

The endemic stingless honey-making bee Melipona (Melikerria) insularissp.n. on Coiba and Rancheria Islands in Pacific Panama is described, together with the proposed sister species, M. ambigua sp.n. from northeast Colombia. The Coiba Island group and Panama mainland were surveyed, yielding one meliponine endemic (M. insularissp.n.) and six meliponine genera and species. The poor Coiba fauna of amphibians and birds corresponds to the poor social bee fauna and suggests habitat barriers generally precluded recolonization from the mainland during glacial periods. Many animals became extinct, yet some remain as relicts. Melipona insularissp.n. was isolated on accreted terranes of Coiba rainforest in the Panama microplate. Morphology suggests that M. insularissp.n. is not a direct descendant of the San Blas-E. Panama endemic Melikerria, M. triplaridis. A phylogenetic hypothesis corroborates disjunct distributions. Rainforest endemics such as Peltogyne purpurea (Fabaceae) and Ptilotrigona occidentalis (Apidae, Meliponini) also occur as relictual, disjunct populations in Central and South America. These may have been isolated before accelerated biotic exchange began 2.4 Ma. Our work supports the geological findings of both a volcanic arc and the San Blas massif providing a substantial bridge for Melikerria from Colombia and Panama in Eocene to Miocene times. We suggest there have been taxon cycles permitting recolonization during glaciations, whereby colonies of M. insularissp.n. were able to recolonize Rancheria, a 250 ha island, 2 km from Coiba. However, rafting colonies nesting in trees, carried on vegetation mats, may have produced founding populations of Melipona in Central America and on oceanic islands such as Coiba.

Natural regeneration in abandoned fields following intensive agricultural land use in an Atlantic Forest Island, Brazil

The time required to regrowth a forest in degraded areas depends on how the forest is removed and on the type of land use following removal. Natural regeneration was studied in abandoned old fields after intensive agricultural land use in areas originally covered by Brazilian Atlantic Forests of the Anchieta Island, Brazil in order to understand how plant communities reassemble following human disturbances as well as to determine suitable strategies of forest restoration. The fields were classified into three vegetation types according to the dominant plant species in: 1) Miconia albicans (Sw.) Triana (Melastomataceae) fields, 2) Dicranopteris flexuosa (Schrader) Underw. (Gleicheniaceae) thickets, and 3) Gleichenella pectinata (Willd.) Ching. (Gleicheniaceae) thickets. Both composition and structure of natural regeneration were compared among the three dominant vegetation types by establishing randomly three plots of 1 x 3 m in five sites of the island. A gradient in composition and abundance of species in natural regeneration could be observed along vegetation types from Dicranopteris fern thickets to Miconia fields. The gradient did not accurately follow the pattern of spatial distribution of the three dominant vegetation types in the island regarding their proximity of the remnant forests. A complex association of biotic and abiotic factors seems to be affecting the seedling recruitment and establishment in the study plots. The lowest plant regeneration found in Dicranopteris and Gleichenella thickets suggests that the ferns inhibit the recruitment of woody and herbaceous species. Otherwise, we could not distinguish different patterns of tree regeneration among the three vegetation types. Our results showed that forest recovery following severe anthropogenic disturbances is not direct, predictable or even achievable on its own. Appropriated actions and methods such as fern removal, planting ground covers, and enrichment planting with tree species were suggested in order to restore the natural forest regeneration process in the abandoned old fields.

Multiple Island Chains in Primary Resonances.

We analyse the dynamics of a relativistic particle moving in a uniform magnetic field and perturbed by a stationary electrostatic wave. We show that a pulsed wave produces an infinite number of perturbing terms with the same winding number. The perturbation coupling alters the number of island chains as a function of the parameters of the wave. We also observe that the number of chains in is always even if the number of islands in each chain is odd.