70 research outputs found
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Origin of accretionary lapilli from the Pompeii and Avellino deposits of Vesuvius
Accretionary lapilli from the Pompeii and Avellino Plinian ash deposits of Vesuvius consist of centimeter-sized spheroids composed of glass, crystal, and lithic fragments of submillimeter size. The typical structure of the lapilli consists of a central massive core surrounded by concentric layers of fine ash with concentrations of larger clasts and vesicles and a thin outer layer of dust. Clasts within the lapilli larger than 125 ..mu..m are extremely rare. The median grain-size of the fine ash is about 50 ..mu..m and the size-distribution is well sorted. Most constituent particles of accretionary lapilli display blocky shapes characteristic of grains produced by phreatomagmatic hydroexplosions. We have used the scanning electron microscope (SEM) in conjunction with energy dispersive spectral analysis (EDS) to investigate the textural and chemical variation along traverses from the core to the rim of lapilli from Vesuvius
Infection with the hepatitis C virus causes viral genotype-specific differences in cholesterol metabolism and hepatic steatosis
Lipids play essential roles in the hepatitis C virus (HCV) life cycle and patients with chronic HCV infection display disordered lipid metabolism which resolves following successful anti-viral therapy. It has been proposed that HCV genotype 3 (HCV-G3) infection is an independent risk factor for hepatocellular carcinoma and evidence suggests lipogenic proteins are involved in hepatocarcinogenesis. We aimed to characterise variation in host lipid metabolism between participants chronically infected with HCV genotype 1 (HCV-G1) and HCV-G3 to identify likely genotype-specific differences in lipid metabolism. We combined several lipidomic approaches: analysis was performed between participants infected with HCV-G1 and HCV-G3, both in the fasting and non-fasting states, and after sustained virological response (SVR) to treatment. Sera were obtained from 112 fasting patients (25% with cirrhosis). Serum lipids were measured using standard enzymatic methods. Lathosterol and desmosterol were measured by gas-chromatography mass spectrometry (MS). For further metabolic insight on lipid metabolism, ultra-performance liquid chromatography MS was performed on all samples. A subgroup of 13 participants had whole body fat distribution determined using in vivo magnetic resonance imaging and spectroscopy. A second cohort of (non-fasting) sera were obtained from HCV Research UK for comparative analyses: 150 treatment naïve patients and 100 non-viraemic patients post-SVR. HCV-G3 patients had significantly decreased serum apoB, non-HDL cholesterol concentrations, and more hepatic steatosis than those with HCV-G1. HCV-G3 patients also had significantly decreased serum levels of lathosterol, without significant reductions in desmosterol. Lipidomic analysis showed lipid species associated with reverse cholesterol transport pathway in HCV-G3. We demonstrated that compared to HCV-G1, HCV-G3 infection is characterised by low LDL cholesterol levels, with preferential suppression of cholesterol synthesis via lathosterol, associated with increasing hepatic steatosis. The genotype-specific lipid disturbances may shed light on genotypic variations in liver disease progression and promotion of hepatocellular cancer in HCV-G3
Infection with the hepatitis C virus causes viral genotype-specific differences in cholesterol metabolism and hepatic steatosis
Background: Lipids play essential roles in the hepatitis C virus (HCV) life cycle and patients with chronic HCV infection display disordered lipid metabolism which resolves following successful anti-viral therapy. It has been proposed that HCV genotype 3 (HCV-G3) infection is an independent risk factor for hepatocellular carcinoma and evidence suggests lipogenic proteins are involved in hepatocarcinogenesis. Aims: We aimed to characterise variation in host lipid metabolism between participants chronically infected with HCV genotype 1 (HCV-G1) and HCV-G3 to identify likely genotype-specific differences in lipid metabolism. Methods: We combined several lipidomic approaches: analysis was performed between participants infected with HCV-G1 and HCV-G3, both in the fasting and non-fasting states, and after sustained virological response (SVR) to treatment. Sera were obtained from 112 fasting patients (25% with cirrhosis). Serum lipids were measured using standard enzymatic methods. Lathosterol and desmosterol were measured by gas-chromatography mass spectrometry (MS). For further metabolic insight on lipid metabolism, ultra-performance liquid chromatography MS was performed on all samples. A subgroup of 13 participants had whole body fat distribution determined using in vivo magnetic resonance imaging and spectroscopy. A second cohort of (non-fasting) sera were obtained from HCV Research UK for comparative analyses: 150 treatment naïve patients and 100 non-viraemic patients post-SVR. Results: HCV-G3 patients had significantly decreased serum apoB, non-HDL cholesterol concentrations, and more hepatic steatosis than those with HCV-G1. HCV-G3 patients also had significantly decreased serum levels of lathosterol, without significant reductions in desmosterol. Lipidomic analysis showed lipid species associated with reverse cholesterol transport pathway in HCV-G3. Conclusions: We demonstrated that compared to HCV-G1, HCV-G3 infection is characterised by low LDL cholesterol levels, with preferential suppression of cholesterol synthesis via lathosterol, associated with increasing hepatic steatosis. The genotype-specific lipid disturbances may shed light on genotypic variations in liver disease progression and promotion of hepatocellular cancer in HCV-G3
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Geothermal resource evaluation of Castle Hot Springs, Arizona
The purpose of this report is to define the geothermal system that supplies the hot water for Castle Hot Spring. An attempt was made to specify the "reservoir" temperature and to model possible sources of heat. This report summarizes our findings and presents the important supporting information in the various tables and figures. Additional data, including details of the techniques and methodologies used in the investigation, will be recorded in an Arizona State University MS thesis (Satkin, in preparation, 1980). Appendices I and II are two papers resulting from the funded work on Castle Hot Spring. Our geologic feasibility study consisted of five parts: 1) construction of a detailed geologic map of hot spring area, 2) production of geologic cross sections, 3) calculation of water geothermometry based on repeated analyses, 4) measurement of geothermal profiles in shallow wells, and 5) speculation on models for the heat source. p.51Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]
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Geothermal resource evaluation of Castle Hot Springs, Arizona
The purpose of this report is to define the geothermal system that supplies the hot water for Castle Hot Spring. An attempt was made to specify the "reservoir" temperature and to model possible sources of heat. This report summarizes our findings and presents the important supporting information in the various tables and figures. Additional data, including details of the techniques and methodologies used in the investigation, will be recorded in an Arizona State University MS thesis (Satkin, in preparation, 1980). Appendices I and II are two papers resulting from the funded work on Castle Hot Spring. Our geologic feasibility study consisted of five parts: 1) construction of a detailed geologic map of hot spring area, 2) production of geologic cross sections, 3) calculation of water geothermometry based on repeated analyses, 4) measurement of geothermal profiles in shallow wells, and 5) speculation on models for the heat source. p.51Documents in the AZGS Documents Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected])
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Geologic Guidebook 4 - Highways of Arizona: Arizona Highways 87, 88 and 188
Arizona is truly a land of scenic beauty and geologic marvels. The arid. climate and great relief combine to expose geology in a dramatic fashion equaled by few other places in North America. This guidebook is the fourth of a series being issued by the Arizona Bureau of Mines to acquaint tourists and residents of this state with its geology. It is hoped that the text will appeal to the amateur and layman as well as professional geologists and engineers. This is not a textbook, however, and the conceptual aspects of geologic phenomena are not treated in detail. The reader should consult introductory textbooks to learn such things as why volcanoes erupt and mountain ranges rise. What we have attempted to do is to call to the attention of the public specific examples of geology which occur along our highways. We hope this will make your trip a little more satisfying.Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]
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