758 resultados para southeastern Pacific


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The cosmopolitan family Calamoceratidae Ulmer, 1906, has 8 living genera, among them Phylloicus Muller, 1880, with species distributed from South to Central America. This genus is characterized by its dark-colored adults (brown to black) with diurnal to crepuscular habits. In this paper, the adults, pupae, and larvae of Phylloicus camargoi n. sp. are described and illustrated. The new species is easily diagnosed by male tergum X bearing a short, digitate, setose, basodorsal process; 2 short, digitate, hairless, lateral processes; and 2 pairs of very short processes on the posterior margin: a pair of digitate, hairless, posterolateral processes, and a pair of posteromesal processes. Additional diagnostic characters are the presence of 3 color bands on the forewings, 2 golden longitudinal bands and a white transversal one.

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The mantis shrimp Squilla biformis is the most conspicuous and abundant stomatopod captured during benthic trawling operations off the Pacific coast of Costa Rica. Due to its abundance, this species is considered a potential fisheries resource for the region. Nevertheless, its life history is practically unknown. The present study describes the population demography, spatial distribution and behaviour of S. biformis from Pacific Costa Rica. The population was principally composed of individuals between 20 and 32 mm carapace length (CL), forming 2 age groups. Individuals of 35 to 45 mm CL and > 45 mm CL were poorly represented. We assume that larger individuals are more frequent at greater depths (probably on the continental slope), thus out of the reach of the fishing vessels used in our study. Males outnumbered females, as observed in other stomatopods. Visual evidence of their behaviour demonstrates that the adults in this species possess a benthic and pelagic life style. Largest numbers of individuals (50% of the total) were found between 240 to 260 m, the same bathymetric range that was historically occupied by commercial shrimps. This shift may be related to intense fishing activities. We observed a synchronized moulting of females and males during less luminous (third and fourth) lunar phases. The evolutionary development of a group moulting system could confer advantages to S. biformis in comparison to other stomatopods whose moulting process is individual and asynchronous.

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Stibadocerina Alexander, a monotypic genus, includes the only known Neotropical species of the family Cylindrotomidae, S. chilensis Alexander, 1929, from South Central Chile (ca. 36 degrees 50`S-42 degrees 17`S). In this paper, Stibadocerina chilensis is redescribed and illustrated in detail. A study of wing-vein homology in the subfamily Stibadocerinae is provided, to identify the components of the reduced radial sector in Stibadocerina and related taxa. The proposed hypotheses of wing-vein homology are tested, and the systematic position of Stibadocerina is assessed through a cladistic analysis of 13 characters of the male imago, scored for exemplar species of the four genera included in the Stibadocerinae. A single most parsimonious tree supports the monophyly of the Stibadocerinae and the following relationships among its included genera: Stibadocerodes [Stibadocera (Stibadocerella + Stibadocerina)]. The subfamily includes one example of a vicariant distribution with a sister-group relationship between South Central Chilean and East Asian taxa, and supports a biogeographical interpretation of an ancestral trans-Pacific biota.

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Osflintia manu, new genus, new species, of long-horned caddisfly (Leptoceridae: Triplectidinae: Grumichellini) is described and illustrated from southeastern Peru. The phylogeny of Grumichellini Morse (Leptoceridae: Triplectidinae) is revisited and hypotheses of homology of some morphological characters are reconsidered. The monophyly of the tribe is corroborated and the phylogenetic relationships of its included genera are inferred to be (Triplexa (Gracilipsodes ((Grumichella, Amazonatolica) (Atanatolica, Osflintia, n. gen.)))) from adult and larval characters. Diagnostic characters of the new genus include the following: reduced tibial spur formula (2, 2, 2), loss of forewing crossvein sc-r1, hind wing discoidal cell closed, hind wing fork IV present, pair of long setae on tergum IX of the male genitalia, and pair of processes on the apex of segment X.

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Multitemporal Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) imagery was used to assess coastline morphological changes in southeastern Brazil. A spectral linear mixing approach (SLMA) was used to estimate fraction imagery representing amounts of vegetation, clean water (a proxy for shade) and soil. Fraction abundances were related to erosive and depositional features. Shoreline, sandy banks (including emerged and submerged banks) and sand spits were highlighted mainly by clean water and soil fraction imagery. To evaluate changes in the coastline geomorphic features, the fraction imagery generated for each data set was classified in a contextual approach using a segmentation technique and ISOSEG, an unsupervised classification. Evaluation of the classifications was performed visually and by an error matrix relating ground-truth data to classification results. Comparison of the classification results revealed an intense transformation in the coastline, and that erosive and depositional features are extremely dynamic and subject to change in short periods of time.

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Four viruses have been reported from taro; Dasheen mosaic virus (DsMV), Taro bacilliform virus (TaBV) and two putative rhabdoviruses, Colocasia bobone disease virus (CBDV) and Taro vein chlorosis virus (TaVCV). A fifth virus, tentatively named Taro reovirus (TaRV), has also been recently identified. The distribution of these viruses throughout the Pacific Islands, and the symptoms associated with their infection, are unknown in many cases due to a lack of sensitive diagnostic tests. We have used recently developed PCR-based diagnostic tests to survey taro growing in 11 Pacific Island countries for the presence of known viruses. DsMV and TaBV were widespread, whereas TaVCV and TaRV were more restricted in their distribution. CBDV was restricted to PNG and Solomon Islands and was always associated with the two most serious viral diseases of taro; alomae disease and bobone disease, but the causal agent of these two diseases remains unclear.

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Few prospective data from the Asia Pacific region are available relating body mass index to the risk of diabetes. Our objective was to provide reliable age, sex and region specific estimates of the associations between body mass index and diabetes. Twenty-seven cohort studies from Asia, New Zealand and Australia, including 154,989 participants, contributed 1,244,793 person-years of follow-up. Outcome data included a combination of incidence of diabetes (based on blood glucose measurements) and fatal diabetes events. Hazard ratios were calculated from Cox models, stratified by sex and cohort, and adjusted for age at risk and smoking. During follow-up (mean = 8 years), 75 fatal diabetes events and 242 new cases of diabetes were documented. There were continuous positive associations between baseline body mass index and risk of diabetes with each 2 kg/m(2) lower body mass index associated with a 27% (23-30%) lower risk of diabetes. The associations were stronger in younger age groups, and regional comparisons demonstrated slightly stronger associations in Asian than in Australasian cohorts (P = 0.04). This overview provides evidence of a strong continuous association between body mass index and diabetes in the Asia Pacific region. The results indicate considerable potential for reduction in incidence of diabetes with population-wide lowering of body mass index in this region.

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There is concern that Pacific island economies dependent on remittances of migrants will endure foreign exchange shortages and declining Living standards as remittance levels drop due to lower migration rates and the belief that migrants' willingness to remit decreases over time. The empirical validity of the remittance-decay hypothesis has never been tested. From survey data on Tongan and Western Samoan migrants in Sydney, this paper estimates remittance functions using Tobit regression analysis. It is found that the remittance-decay hypothesis has no empirical validity and migrants are motivated by factors other than altruistic family support, including asset accumulation and investment back home. (C) 1997 Elsevier Science Ltd.

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