10 research outputs found
Slice of intraoceanic arc: Insights from the first multichannel seismic reflection profile across the South Sandwich island arc
We present the first multichannel seismic (MCS) reflection line that crosses the South Sandwich Trench, South Sandwich island arc, and East Scotia Sea backarc basin. The line is used in combination with earthquake catalogue data to interpret the strain distribution across the Sandwich plate and the relationship of forearc structures to processes operating at the trench. The MCS data reveal a 1.2-km-high fault scarp associated with a 20-km-wide arcward-tilted block in the mid-forearc; these features indicate large-scale gravitational collapse, and earthquake data are consistent with trench-normal extension at shallow depth in this area. There is, however, little evidence of distributed extension within the interior of the Sandwich plate. The MCS data show a small frontal wedge that achieves its maximum thickness only 18 km from the trench. Backarc magnetic data, mid-forearc extension, and the small size of the frontal wedge are all consistent with long-term and ongoing subduction erosion. Earthquake data suggest that this erosion is taking place in an environment of low interplate stress
Two MSA 2 peptides that bind to human red blood cells are relevant to Plasmodium falciparum
The infra-red spectra of complexes of beryllium with tri-n-octylphosphine oxide and di(2-ethylhexyl) phosphoric acid
Bioelectrical Impedance Analysis: A Promising Predictive Tool for Nutritional Assessment in Continuous Ambulatory Peritoneal Dialysis Patients
Endocrinological Function in Schizophrenic Patients under Haloperidol Treatment: Plasma PRL, HGH and 5HT Levels after L-5HTP Loading
Padrões de floração e frutificação de árvores da Amazônia Maranhense Flowering and Fruiting Patterns of the Maranhense Amazon Rainforest Trees
Estudos fenológicos em nível de comunidades podem facilitar a compreensão do comportamento das espécies diante de alterações nos ecossistemas, além de refletir a distribuição anual de tipos específicos de recursos. Este trabalho buscou definir os padrões gerais e a sazonalidade de floração e frutificação de uma comunidade em duas áreas de floresta na Amazônia Maranhense, uma não perturbada e outra submetida a corte seletivo. A vegetação corresponde às matas de cipós das florestas amazônicas, alternando matas densas e abertas, de alta biomassa. Valores médios anuais de temperatura variam entre 24,5º C e 26,0º C, e entre 1400 mm e 1800 mm de precipitação, com um período seco de 5 a 6 meses, de junho a novembro. Foram analisadas a floração e a frutificação de 89 espécies arbóreas, de agosto de 1994 a junho de 1996. As espécies foram agrupadas em: árvores do sub-dossel, árvores do estrato superior e árvores que ocorrem em ambos os estratos. Foi feita comparação entre grupos (estratos, tipos de floresta e mecanismos de dispersão) e possíveis correlações com a precipitação foram investigadas. Quinze espécies estudadas foram exclusivas do estrato inferior e 63 do estrato superior da floresta; 17 espécies foram registradas apenas na mata nativa e 37 apenas na mata manejada. A maioria das espécies é zoocórica (62,9 %). A floração e a frutificação ocorreram durante todo o ano, com pico de floração de outubro a dezembro e picos de frutificação de março a julho e de outubro a dezembro. Os resultados obtidos demonstram uma grande sincronia na floração e frutificação dos indivíduos, e confirmam a relação entre esses processos e a variação na precipitação ao longo do ano, e que plantas de ambientes diferenciados exibem comportamentos fenológicos diferentes. Os padrões observados foram semelhantes entre as áreas e a outros estudos na Amazônia.<br>Community level phonological studies can facilitate the understanding of species behavior as a result of ecosystem changes, further reflecting on the annual allotment of specific resources. The aim of the present study was to define the general patterns, flowering and fruiting seasonality from a community in two forest areas of the Maranhense Amazon Rainforest: a non-disturbed area and another submitted to selective logging. The vegetation is composed of Amazon forest lianas alternating between dense and open high biomass forest. Average annual temperature varies between 24.5O C and 26.0O C, with precipitation ranging from 1400 mm to 1800 mm, and a dry season between June and November. Flowering and fruiting of 89 species were analyzed from August 1994 to June 1996. The species were grouped as follows: sub-dossal, upper strata, and trees occurring in both strata. Comparison was made between groups (strata, types of forest and mechanisms for dispersal) and possible correlations with rainfall were investigated. Fifteen studied species were solely from the lower strata, and 63 from the upper forest strata; 17 species were recorded only in native forest and 37 in managed forest. Most species (62.9 %) is zoochorous. Flowering and fruiting take place throughout the year with flowering peak from October to December and fruiting peaks from March to July and from October to December. The results showed a great synchrony in flowering and fruiting of individuals, and confirm the relationship between these cases and the variation in rainfall throughout the year, and that plants of different environments exhibit phonological behavior different. The observed flowering and fruiting patterns were similar between the areas and comparable to other studies in the Amazon Rainforest