RESUMO
Dehydration of the oceanic subducting slab promotes the formation of magmatic arcs, intra-slab intermediate-depth seismicity, and hydration of the overlying mantle wedge. However, the complex permeability structure of the overriding plate controls the magma and fluid migration and their accumulation at shallower depths. In this regard, mapping the inner structure of the overriding crust and mantle is crucial to understand the magmatic and hydrological processes in subduction zones. We integrate 3-D P-wave, [Formula: see text], and electrical resistivity tomographic models of the northern Chilean subduction zone to map the magmatic and fluids derived from the subducting oceanic Nazca plate. Results show a continental crust relatively thick (50-65 km) characterized by a lower zone of high [Formula: see text] values (7.2-7.6 km/s), which is interpreted as the presence of plutonic rocks. The mantle lithospheric wedge is weakly hydrated ([Formula: see text] = 1.75-1.8) while the forearc continental crust is traversed by regions of reduced electrical resistivity values ([Formula: see text] [Formula: see text]) interpreted as zones of relatively high permeability/fracturing and fluid content. These regions spatially correlate with upper plate trans-lithospheric deformation zones. Ascending melts accumulate preferentially in the back-arc, whereas hydrothermal systems form trenchward of the volcanic arc. The results highlight the complex permeability structure of the upper South American plate.
RESUMO
Abstract Even though the Onychophora represent a whole phylum, observations of their activity pattern in nature are almost non-existent. Here we report on the relationship between humidity and light and activity pattern of a new species of velvet worm, genus Epiperipatus, from four years of field observations in the South Pacific of Costa Rica. We found that most activity occurs during the driest and darkest nights of the year, in contrast with theoretical predictions.
Resumo Onychophora constituem um filo de animais. Não obstante, as observações do comportamento sazonal das espécies de "peripatos" na natureza são praticamente inexistentes. Com base em quatro anos de observações em campo, nós demostramos a relação entre umidade e luz, e padrão de atividade diária de uma nova espécie no gênero Epiperipatus, do Pacífico Sul da Costa Rica. Descobrimos que a maioria das atividades ocorre durante as noites mais secas e mais escuras do ano, em total contraste com as previsões teóricas.
Assuntos
Animais , Comportamento Animal/fisiologia , Umidade , Invertebrados/efeitos da radiação , Invertebrados/fisiologia , Luz , Especificidade da Espécie , Temperatura , Dinâmica Populacional , Clima , Ecossistema , Costa Rica , BiodiversidadeRESUMO
Even though the Onychophora represent a whole phylum, observations of their activity pattern in nature are almost non-existent. Here we report on the relationship between humidity and light and activity pattern of a new species of velvet worm, genus Epiperipatus, from four years of field observations in the South Pacific of Costa Rica. We found that most activity occurs during the driest and darkest nights of the year, in contrast with theoretical predictions.
Assuntos
Comportamento Animal/fisiologia , Umidade , Invertebrados/fisiologia , Invertebrados/efeitos da radiação , Luz , Animais , Biodiversidade , Clima , Costa Rica , Ecossistema , Dinâmica Populacional , Especificidade da Espécie , TemperaturaRESUMO
A pilot study was carried out in the Nuclear Medicine Department of the National Institute of Oncology and Radiobiology to learn the diagnostic efficacy of the 99mTc-HMPAO scintigraphy in the detection of cutaneous melanoma, distant and local metastases, in patients with a confirmed histological diagnosis. The planar and/or SPECT scintigraphy was performed in 17 patients and revealed 90% sensitivity for the detection of the disease. We calculated the tumor/background index in all the images obtained and found a value greater than 1 in every case. Thus, we can affirm that the 99mTc-HMPAO accumulation in tumors was higher than the background in all cases. We recommend that this procedure be considered in the follow up of these patients as a new diagnostic method which is very useful in the determination of the patient stage and prognostic evaluation.
Assuntos
Melanoma/diagnóstico por imagem , Metástase Neoplásica/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Compostos Radiofarmacêuticos , Neoplasias Cutâneas/diagnóstico por imagem , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Seguimentos , Humanos , Masculino , Melanoma/patologia , Melanoma/cirurgia , Pessoa de Meia-Idade , Projetos Piloto , Sensibilidade e Especificidade , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgiaRESUMO
Sabiá virus, one of five arenaviruses from South America known to cause hemorrhagic fever in humans, emerged in 1990 when it was isolated from a fatal case in Sao Paulo, Brazil. Subsequently, it has caused two laboratory-acquired infections. Its natural distribution and host are still unknown. Using viral RNA and multiple polymerase chain reaction products as templates, the nucleotide sequence of the small (S) RNA segment of Sabiá virus, which codes for the nucleocapsid (N) and glycoprotein precursor, was determined. This virus shares an ambisense genome in common with other arenaviruses, although it has a unique predicted three stem--loop structure in the S RNA intergenic region. Phylogenetic analysis of a portion of the N gene sequence confirmed that Sabiá virus is distinct from all other members of the Arenaviridae and shares a progenitor with Junin, Machupo, Tacaribe, and Guanarito viruses.
Assuntos
Arenavirus do Novo Mundo/classificação , Arenavirus do Novo Mundo/genética , Febre Hemorrágica Americana/virologia , Sequência de Aminoácidos , Animais , Arenavirus do Novo Mundo/isolamento & purificação , Sequência de Bases , Brasil , Capsídeo/genética , Chlorocebus aethiops , DNA Viral , Humanos , Camundongos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Filogenia , Precursores de Proteínas/genética , RNA Viral , Homologia de Sequência de Aminoácidos , Células Vero , Proteínas do Core Viral/genéticaAssuntos
Arenavirus do Novo Mundo , Febre Hemorrágica Americana/tratamento farmacológico , Controle de Infecções/métodos , Infecção Laboratorial/tratamento farmacológico , Ribavirina/uso terapêutico , Brasil , Busca de Comunicante , Febre Hemorrágica Americana/virologia , Humanos , Infecção Laboratorial/virologia , Masculino , Pessoa de Meia-Idade , Isolamento de Pacientes , Gestão da Segurança/métodos , Precauções UniversaisAssuntos
Ebolavirus , Febres Hemorrágicas Virais/epidemiologia , Côte d'Ivoire/epidemiologia , República Democrática do Congo/epidemiologia , Surtos de Doenças/prevenção & controle , Ebolavirus/patogenicidade , Febres Hemorrágicas Virais/prevenção & controle , Febres Hemorrágicas Virais/transmissão , Humanos , América do Sul/epidemiologiaRESUMO
Operator seats (Models 050 and 500, Möve) were examined with vertical sinusoidal whole-body vibration (WBV) in the frequency range from 1 to 40 Hz (1.5 and 3.0 ms-2 rms) and with simulated stochastic vibration of combines for the harvest of sugarcane. Six male subjects volunteered for the experiments. The subjective assessments of operator seats by cross-modality matching, paired comparisons, and questionnaires were compared with data of a hard experimental seat. Transmitted WBV and subjective evaluation correlated partially only. Suggestions are derived for the improvement of the seats tested.
Assuntos
Doenças dos Trabalhadores Agrícolas/prevenção & controle , Agricultura/instrumentação , Atitude , Vibração/efeitos adversos , Adulto , Cuba , Desenho de Equipamento , Humanos , MasculinoRESUMO
Para los odontólogos dedicados al tratamiento dental infantil, es necesario conocer los posibles riesgos de nuestra terapia, así como los accidentes que pueden ocurrir durante y después de realizada la misma. De esta manera, teniéndolos presentes, así como, conociendo los diferentes tratamientos para solucionar estas emergencias, podremos salvar a nuestro paciente de situaciones que van desde las más leves a aquellas que pueden incluso poner en peligro su vida