Forearc carbon sink reduces long-term volatile recycling into the mantle.

Carbon and other volatiles in the form of gases, fluids or mineral phases are transported from Earth's surface into the mantle at convergent margins, where the oceanic crust subducts beneath the continental crust. The efficiency of this transfer has profound implications for the nature and scale of geochemical heterogeneities in Earth's deep mantle and shallow crustal reservoirs, as well as Earth's oxidation state. However, the proportions of volatiles released from the forearc and backarc are not well constrained compared to fluxes from the volcanic arc front. Here we use helium and carbon isotope data from deeply sourced springs along two cross-arc transects to show that about 91 per cent of carbon released from the slab and mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition. Around an additional three per cent is incorporated into the biomass through microbial chemolithoautotrophy, whereby microbes assimilate inorganic carbon into biomass. We estimate that between 1.2 × 108 and 1.3 × 1010 moles of carbon dioxide per year are released from the slab beneath the forearc, and thus up to about 19 per cent less carbon is being transferred into Earth's deep mantle than previously estimated.

Validation of the Social Phobia and Anxiety Inventory for Children (SPAI-C) in a sample of Brazilian children.

The purpose of the present study was to examine the factor structure and psychometric properties of the Social Phobia and Anxiety Inventory for Children (SPAI-C), an instrument developed in the United States and applied to a sample of Brazilian schoolchildren. The process included the translation of the original material from English into Portuguese by two bilingual psychiatrists and a back translation by a bilingual physician. Both the front and back translations were revised by a bilingual child psychiatrist. The study was performed using a cross-sectional design and the Portuguese version of the SPAI-C was applied to a sample of 1954 children enrolled in 3rd to 8th grade attending 2 private and 11 public schools. Eighty-one subjects were excluded due to an incomplete questionnaire and 2 children refused to participate. The final sample consisted of 1871 children, 938 girls (50.1%) and 933 boys (49.8%), ranging in age from 9 to 14 years. The majority of the students were Caucasian (89.0%) and the remainder were African-Brazilian (11.0%). The Pearson product-moment correlation showed that the two-week test-retest reliability coefficient was r = 0.780 and Cronbach's alpha was 0.946. The factor structure was almost similar to that reported in previous studies. The results regarding the internal consistency, the test-retest reliability and the factor structure were similar to the findings obtained in studies performed on English speaking children. The present study showed that the Portuguese language version of SPAI-C is a reliable and valid measure of social anxiety for Brazilian children.

Validation of the Social Phobia and Anxiety Inventory for Children (SPAI-C) in a sample of Brazilian children

The purpose of the present study was to examine the factor structure and psychometric properties of the Social Phobia and Anxiety Inventory for Children (SPAI-C), an instrument developed in the United States and applied to a sample of Brazilian schoolchildren. The process included the translation of the original material from English into Portuguese by two bilingual psychiatrists and a back translation by a bilingual physician. Both the front and back translations were revised by a bilingual child psychiatrist. The study was performed using a cross-sectional design and the Portuguese version of the SPAI-C was applied to a sample of 1954 children enrolled in 3rd to 8th grade attending 2 private and 11 public schools. Eighty-one subjects were excluded due to an incomplete questionnaire and 2 children refused to participate. The final sample consisted of 1871 children, 938 girls (50.1 percent) and 933 boys (49.8 percent), ranging in age from 9 to 14 years. The majority of the students were Caucasian (89.0 percent) and the remainder were African-Brazilian (11.0 percent). The Pearson product-moment correlation showed that the two-week test-retest reliability coefficient was r = 0.780 and Cronbach's alpha was 0.946. The factor structure was almost similar to that reported in previous studies. The results regarding the internal consistency, the test-retest reliability and the factor structure were similar to the findings obtained in studies performed on English speaking children. The present study showed that the Portuguese language version of SPAI-C is a reliable and valid measure of social anxiety for Brazilian children.

Molecular epidemiology of dengue virus type 3 in Venezuela.

During the past 40 years, dengue haemorrhagic fever and dengue shock syndrome (DHF/DSS) have emerged in humans, with approximately 3 million cases reported and over 58 000 deaths. Dengue virus serotypes 1, 2 and 4 (DENV-1, -2 and -4) have been co-circulating in Venezuela for at least the past 10 years, causing minor or major outbreaks of dengue fever (DF) and DHF/DSS. The first recorded outbreak due to DENV-3 in Venezuela dates to 1964 and the virus then seems to have disappeared. However, DENV-3 re-appeared recently (in July, 2000) in Venezuela after 32 years of absence and produced a prolonged major outbreak, which, by the end of 2001, involved 83 180 cases of dengue, mostly DF (92 %). Previous phylogenetic studies revealed that the DENV-3 circulating during the 1960s Latin American outbreak was a genotype V virus. To gain a better understanding of the nature of the current epidemic, the complete sequence was determined of the envelope (E) gene of 15 Venezuelan DENV-3 viruses isolated during 2000 and 2001 from patients presenting with different disease severity. Sequence data were used in phylogenetic comparisons with global samples of DENV-3. Analysis revealed that the strain circulating in Venezuela is closely related to isolates that were previously present in Panama and Nicaragua in 1994 and since then have spread through Central American countries and Mexico. This study also confirms previous reports showing that the DENV-3 strain currently circulating in the Americas is related to the strain that caused DHF epidemics in Sri Lanka and India in 1989-1991 (genotype III). Finally, no evidence of the re-emergence of the strain that circulated in Venezuela in the late 1960s and 1970s (genotype V) was found.

Molecular diversity of arbuscular mycorrhizal fungi and patterns of host association over time and space in a tropical forest.

We have used molecular techniques to investigate the diversity and distribution of the arbuscular mycorrhizal (AM) fungi colonizing tree seedling roots in the tropical forest on Barro Colorado Island (BCI), Republic of Panama. In the first year, we sampled newly emergent seedlings of the understory treelet Faramea occidentalis and the canopy emergent Tetragastris panamensis, from mixed seedling carpets at each of two sites. The following year we sampled surviving seedlings from these cohorts. The roots of 48 plants were analysed using AM fungal-specific primers to amplify and clone partial small subunit (SSU) ribosomal RNA gene sequences. Over 1300 clones were screened for random fragment length polymorphism (RFLP) variation and 7% of these were sequenced. Compared with AM fungal communities sampled from temperate habitats using the same method, the overall diversity was high, with a total of 30 AM fungal types identified. Seventeen of these types have not been recorded previously, with the remainder being similar to types reported from temperate habitats. The tropical mycorrhizal population showed significant spatial heterogeneity and nonrandom associations with the different hosts. Moreover there was a strong shift in the mycorrhizal communities over time. AM fungal types that were dominant in the newly germinated seedlings were almost entirely replaced by previously rare types in the surviving seedlings the following year. The high diversity and huge variation detected across time points, sites and hosts, implies that the AM fungal types are ecologically distinct and thus may have the potential to influence recruitment and host composition in tropical forests.

Craniometric variation in a population of mantled howler monkeys (Alouatta palliata): evidence of size selection in females and growth in dentally mature males.

A large body of work on monkey cranial metrics (involving conclusions about interspecific variation, sexual dimorphism, and ontogeny) depends on the assumptions that growth effectively ceases with dental maturity and that intraspecific variation is negligible. We test these assumptions by examining variation in 39 measurements of 166 dentally mature Alouatta palliata skulls from animals found dead on Barro Colorado Island (BCI), Panama. We also investigate whether this population is under size-based selection, since our found-dead sample reflects the natural mortality in this population. The sample was divided into three age stages by occlusal wear (A-C, least to most wear). Female stage A means are significantly smaller than female stage B means for three cranial measures. Female stage B means are significantly smaller than female stage C means for five cranial measures. Male stage A means are significantly smaller than male stage B means for 21 cranial measures. Multivariate analyses confirm this trend of expansion between adult age stages. The dental metric and suture closure data suggest that the cranial expansion in females is due to size-based selection, while the cranial expansion in males is due to significant growth after dental maturity. Sexual dimorphism ratios are highly variable across different samples of A. palliata, indicating that dimorphism varies between populations of this species. These results provide insight into the selective forces operating on the BCI howlers and challenge the validity of the many studies which pool subspecies and assume growth ceases with maturity.

Additional approaches to DNA typing of skeletal remains: the search for "missing" persons killed during the last dictatorship in Argentina.

DNA typing techniques are among the most advanced tools for human identification and can contribute to the identification of poorly preserved skeletal remains. Ten thousand people are thought to have been killed during the last dictatorship in Argentina (1976-1983) and there are few official records on the identity of the victims or the location of burials. A mass grave containing 340 skeletons was excavated using archeological methods. A small number of individuals was identified by traditional forensic methods and one family group by mitochondrial DNA (mtDNA) analysis. Due to the lack of antemortem physical information on many of the victims, the application of molecular methods is imperative to speed up the identification process. We have tested two molecular screening methods, Y chromosome-specific short tandem repeats (DYS19, DYS385, DYS389 I, DYS389 II, DYS390, DYS391, DYS392, DYS393) and amplification of autosomal microsatellites using nested primers. These methods can complement solely matrilineal mtDNA sequence data in the identification of "missing" persons.