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1.
Nat Commun ; 10(1): 3237, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324764

RESUMO

Recycling of Earth's crust through subduction and delamination contributes to mantle heterogeneity. Melt inclusions in early crystallised magmatic minerals record greater geochemical variability than host lavas and more fully reflect the heterogeneity of magma sources. To date, use of multiple isotope systems on small (< 300 µm) melt inclusions was hampered by analytical limitations. Here we report the first coupled Sr-Nd-Pb isotope data on individual melt inclusions from potassium-rich lavas from neighbouring Quaternary volcanoes in central Italy and infer the presence of a previously unidentified ancient lower crustal component in the mantle. We suggest derivation from Variscan or older basement included in the upper mantle by either delamination, sediment recycling, subduction erosion and/or slab detachment processes during Cenozoic subduction and collision of the western Mediterranean. The capability to determine isotope ratios in individual melt inclusions permits the detection of distinctive mantle contaminants and can provide insights into how geodynamic processes affect subduction recycling.

2.
IDCases ; 10: 117-121, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29147641

RESUMO

Acute Zika virus (ZIKV) infection is usually mild and self-limiting. Earlier, we reported three cases of fatal acute ZIKV infection in patients without typical signs of ZIKV, but rather with criteria of systemic inflammation response syndrome (SIRS). To follow up these observations, we prospectively included patients at the emergency room with temperature instability and suspected to have acute ZIKV infection, SIRS, or both. A total of 102 patients were included of whom N = 21 (21%) were suspected of acute ZIKV infection, N = 56 (55%) of acute ZIKV infection with SIRS criteria, and N = 25 (24%) of SIRS alone. ZIKV-PCR was positive in N = 21 (20%) patients. Eight (38%) ZIKV-positive patients needed admission to the hospital of whom four (50%) presented with SIRS alone. One ZIKV-positive patient had vascular co-morbidity and died following shock and severe coagulopathy. We confirm the hypothesis that acute ZIKV infection can present atypical and severely with systemic inflammation and have lethal course particularly amongst patients with significant prior disease.

3.
IDCases ; 10: 117-121, October 16, 2017. tab
Artigo em Inglês | MedCarib | ID: biblio-906532

RESUMO

Acute Zika virus (ZIKV) infection is usually mild and self-limiting. Earlier, we reported three cases of fatal acute ZIKV infection in patients without typical signs of ZIKV, but rather with criteria of systemic inflammation response syndrome (SIRS). To follow up these observations, we prospectively included patients at the emergency room with temperature instability and suspected to have acute ZIKV infection, SIRS, or both. A total of 102 patients were included of whom N =21 (21%) were suspected of acute ZIKV infection, N =56 (55%) of acute ZIKV infection with SIRS criteria, and N =25 (24%) of SIRS alone. ZIKV-PCR was positive in N =21 (20%) patients. Eight (38%) ZIKV-positive patients needed admission to the hospital of whom four (50%) presented with SIRS alone. One ZIKV-positive patient had vascular co-morbidity and died following shock and severe coagulopathy. We confirm the hypothesis that acute ZIKV infection can present atypical and severely with systemic inflammation and have lethal course particularly amongst patients with significant prior disease...(AU)


Assuntos
Humanos , Masculino , Feminino , Zika virus , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/epidemiologia , Relatos de Casos , Técnicas de Laboratório Clínico/estatística & dados numéricos , Coinfecção , Evolução Fatal , Testes Sorológicos , Suriname/epidemiologia , Síndrome de Resposta Inflamatória Sistêmica/complicações
4.
Geochem Geophys Geosyst ; 17(8): 3254-3273, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27917071

RESUMO

This study reports the first detailed geochemical characterization of Kolumbo submarine volcano in order to investigate the role of source heterogeneity in controlling geochemical variability within the Santorini volcanic field in the central Aegean arc. Kolumbo, situated 15 km to the northeast of Santorini, last erupted in 1650 AD and is thus closely associated with the Santorini volcanic system in space and time. Samples taken by remotely-operated vehicle that were analyzed for major element, trace element and Sr-Nd-Hf-Pb isotope composition include the 1650 AD and underlying K2 rhyolitic, enclave-bearing pumices that are nearly identical in composition (73 wt.% SiO2, 4.2 wt.% K2O). Lava bodies exposed in the crater and enclaves are basalts to andesites (52-60 wt.% SiO2). Biotite and amphibole are common phenocryst phases, in contrast with the typically anhydrous mineral assemblages of Santorini. The strong geochemical signature of amphibole fractionation and the assimilation of lower crustal basement in the petrogenesis of the Kolumbo magmas indicates that Kolumbo and Santorini underwent different crustal differentiation histories and that their crustal magmatic systems are unrelated. Moreover, the Kolumbo samples are derived from a distinct, more enriched mantle source that is characterized by high Nb/Yb (>3) and low 206Pb/204Pb (<18.82) that has not been recognized in the Santorini volcanic products. The strong dissimilarity in both petrogenesis and inferred mantle sources between Kolumbo and Santorini suggests that pronounced source variations can be manifested in arc magmas that are closely associated in space and time within a single volcanic field.

5.
Environ Sci Pollut Res Int ; 12(2): 89-95, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15859115

RESUMO

BACKGROUND, AIMS AND SCOPE: Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH < 0.3. It is the source of the extremely acidic and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed. METHODS: Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards. RESULTS AND DISCUSSION: The river carries a very high load of SO4, NH4, PO4, Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980-2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1,600 mg/l) and aluminium (up to 3,000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acidic water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acidic irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents' diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis. CONCLUSIONS, RECOMMENDATIONS AND OUTLOOK: In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production.


Assuntos
Metais Pesados/análise , Poluentes da Água/análise , Água/química , Animais , Ecossistema , Monitoramento Ambiental , Fenômenos Geológicos , Geologia , Humanos , Concentração de Íons de Hidrogênio , Indonésia , Invertebrados , Saúde Pública , Rios , Erupções Vulcânicas
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