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The emission of volcanic gases usually precedes eruptive activity, providing both a warning signal and an indication of the nature of the lava soon to be erupted. Additionally, volcanic emissions are a significant source of gases and particles to the atmosphere, influencing tropospheric and stratospheric trace-gas budgets. Despite some halogen species having been measured in volcanic plumes (mainly HCl and HF), little is known about bromine compounds and, in particular, gas-phase reactive bromine species. Such species are especially important in the stratosphere, as reactive bromine-despite being two orders of magnitude less abundant than chlorine-accounts for about one-third of halogen-catalysed ozone depletion. In the troposphere, bromine-catalysed complete ozone destruction has been observed to occur regularly during spring in the polar boundary layers as well as in the troposphere above the Dead Sea basin. Here we report observations of BrO and SO2 abundances in the plume of the Soufrière Hills volcano (Montserrat) in May 2002 by ground-based multi-axis differential optical absorption spectroscopy. Our estimate of BrO emission leads us to conclude that local ozone depletion and small ozone 'holes' may occur in the vicinity of active volcanoes, and that the amount of bromine emitted from volcanoes might be sufficiently large to play a role not only in the stratosphere, but also in tropospheric chemistry. 相似文献
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Blindness and auditory impairment caused by loss of the sodium bicarbonate cotransporter NBC3 总被引:7,自引:0,他引:7
Bok D Galbraith G Lopez I Woodruff M Nusinowitz S BeltrandelRio H Huang W Zhao S Geske R Montgomery C Van Sligtenhorst I Friddle C Platt K Sparks MJ Pushkin A Abuladze N Ishiyama A Dukkipati R Liu W Kurtz I 《Nature genetics》2003,34(3):313-319
Normal sensory transduction requires the efficient disposal of acid (H+) generated by neuronal and sensory receptor activity. Multiple highly sensitive transport mechanisms have evolved in prokaryotic and eukaryotic organisms to maintain acidity within strict limits. It is currently assumed that the multiplicity of these processes provides a biological robustness. Here we report that the visual and auditory systems have a specific requirement for H+ disposal mediated by the sodium bicarbonate cotransporter NBC3 (refs. 7,8). Mice lacking NBC3 develop blindness and auditory impairment because of degeneration of sensory receptors in the eye and inner ear as in Usher syndrome. Our results indicate that in certain sensory organs, in which the requirement to transduce specific environmental signals with speed, sensitivity and reliability is paramount, the choice of the H+ disposal mechanism used is limited. 相似文献
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R. H. Davis B. E. Meyers D. K. Moonka R. H. Melincoff H. A. Platt 《Cellular and molecular life sciences : CMLS》1978,34(2):184-185
Summary The percent distribution of peritoneal fluid cellular content of adult female dogs was recorded and found to be dissimilar to all other species examined, especially in regard to mesothelial cell, polymorphonuclear leukocyte and lymphocyte proportions. 相似文献
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D'Angelo G Polishchuk E Di Tullio G Santoro M Di Campli A Godi A West G Bielawski J Chuang CC van der Spoel AC Platt FM Hannun YA Polishchuk R Mattjus P De Matteis MA 《Nature》2007,449(7158):62-67
The molecular machinery responsible for the generation of transport carriers moving from the Golgi complex to the plasma membrane relies on a tight interplay between proteins and lipids. Among the lipid-binding proteins of this machinery, we previously identified the four-phosphate adaptor protein FAPP2, the pleckstrin homology domain of which binds phosphatidylinositol 4-phosphate and the small GTPase ARF1. FAPP2 also possesses a glycolipid-transfer-protein homology domain. Here we show that human FAPP2 is a glucosylceramide-transfer protein that has a pivotal role in the synthesis of complex glycosphingolipids, key structural and signalling components of the plasma membrane. The requirement for FAPP2 makes the whole glycosphingolipid synthetic pathway sensitive to regulation by phosphatidylinositol 4-phosphate and ARF1. Thus, by coupling the synthesis of glycosphingolipids with their export to the cell surface, FAPP2 emerges as crucial in determining the lipid identity and composition of the plasma membrane. 相似文献
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David J. Koss Benjamin D. Drever Sandra Stoppelkamp Gernot Riedel Bettina Platt 《Cellular and molecular life sciences : CMLS》2013,70(14):2585-2601
Several genetically engineered models exist that mimic aspects of the pathological and cognitive hallmarks of Alzheimer’s disease (AD). Here we report on a novel mouse model generated by targeted knock-in of transgenes containing mutated human amyloid precursor protein (APP) and microtubule-associated protein tau genes, inserted into the HPRT locus and controlled by the CaMKIIα regulatory element. These mice were crossed with an asymptomatic presenilin1A246E overexpressing line to generate PLB1Triple mice. Gene expression analysis and in situ hybridization confirmed stable, forebrain-specific, and gene-dose-dependent transgene expression. Brain tissue harvested from homozygous, heterozygous, and wild-type cohorts aged between 3 and 24 months was analyzed immunohistochemically and electrophysiologically. Homozygous PLB1Triple offspring presented with mostly intracellular cortical and hippocampal human APP/amyloid, first detected reliably at 6 months. Human tau was already uncovered at 3 months (phospho-tau at 6 months) and labeling intensifying progressively with age. Gene-dose dependence was confirmed in age-matched heterozygous females that accumulated less tau and amyloid protein. General excitability of hippocampal neurones was not altered in slices from PLB1Triple mice up to 12 months, but 2-year-old homozygous PLB1Triple mice had smaller synaptically evoked postsynaptic potentials compared with wild types. Synaptic plasticity (paired-pulse depression/facilitation and long-term potentiation) of synaptic CA1 pyramidal cell responses was deficient from 6 months of age. Long-term depression was not affected at any age or in any genotype. Therefore, despite comparatively subtle gene expression and protein build-up, PLB1Triple mice develop age-dependent progressive phenotypes, suggesting that aggressive protein accumulation is not necessary to reconstruct endophenotypes of AD. 相似文献
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Marine ecology: Spring algal bloom and larval fish survival 总被引:2,自引:0,他引:2
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