43,621 research outputs found
Geochemistry of Southeastern Nicaragua lavas and mantle xenoliths from Cerro Mercedes, Costa Rica:
No full textLavas from southeastern Nicaragua were geochemically analyzed, including several from a volcano never before sampled, in order to better understand the relationship between the chemistry of the lavas and the physical parameters of the Central American arc, which include depth to the slab, distance from the trench, slab dip and the age of the downgoing slab. The analyses were done by x-ray fluorescence, by high resolution inductively coupled plasma mass spectrometry, and by thermal ionization mass spectrometry. The results show that the abundance of high-field strength elements in the lavas is particularly influenced by the depth to the slab underlying a volcano and the distance of the volcano from the trench. Additionally, the results show that decompression melting is an important process in the generation of these lavas.
The chemistry of mantle xenoliths from Cerro Mercedes, Costa Rica, were studied to elucidate the compositional and physical state of the mantle wedge underlying Central American. The composition of the mantle wedge is clarified through analyses of the whole rock; information about the physical state of the mantle is obtained from analyses of the minerals that constitute the xenoliths. The analytical methods used for the whole rock chemistry were x-ray fluorescence and high resolution inductively coupled plasma mass spectrometry. Electron probe microscopy and laser ablation inductively coupled plasma mass spectroscopy were used to analyze the minerals. Results show that the mantle wedge composition is predominantly peridotite (~65% modal olivine) that has experienced variable degrees of modification by melt- and fluid- rock reactions, with pockets of cumulate pyroxenite. Although the majority of the peridotites are multi-phase residues, one sample, CM52, may be a first-stage residue. The xenoliths are spinel facies rocks, which correspond to pressures between 1 – 2.5 GPa, and have equilibrium temperatures ranging from 860°C – 1030°C at 1 GPa, which place them between 30km and 85km within the mantle. The potential temperature of the system, based on whole rock major oxide modeling, is 1580°C. Estimated values for the oxidation state of the mantle range from ΔƒO2FMQ +0.9 - ΔƒO2FMQ +3.25 for the peridotites and up to ΔƒO2FMQ +4.05 for the pyroxenites.Ph.D.Includes bibliographical references (p. 278-287)by Fara N. Lindsa
Need for review of the ministerial directive concerning anti-rabies prophylaxis in the light of recent epidemiological evidence [Necessità di una revisione delle direttive ministeriali in tema di profilassi antirabbica alla luce delle recenti evidenze epidemiologiche.]
No full textTetravalent anti-meningococcal vaccine: serologic and clinical evaluation.
No full textMeningococcal disease is the only bacterial meningitis able to cause an epidemic and the mortality due to this disease is all but negligible; therefore the active immunization induced by a vaccine that includes a large portion of Neisseria meningitidis serogroups responsible for the immunization of subjects at risk. Tetravalent vaccine containing polysaccharides of the serogroups A, C, Y, W135 has given good results both for tolerability and immune response. Considering the epidemic situation in Italy, this vaccine could be an excellent strategy "to behead" possible epidemics and/or hyperendemics due to a known serogroups
Need for review of the ministerial directive concerning anti-rabies prophylaxis in the light of recent epidemiological evidence.
No full textWill be added ASA
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Sagfgi di vaccinazione antimeningococcica con vaccini polisaccaridici di cgruppo "A" e "C"
No full textSarà inserito a biblioteche riapert
Survey of air conditioners' characteristics and management in some Italian operating theatres
No full textGli autori riportano i risultati di uno studio multicentrico atto a valutare il benessere termico delle sale operatorie e le caratteristiche di gestione degli impianti di condizionamento presenti, al fine di trarne indicazioni e raccomandazioni da proporre ai fini di una gestione efficace
Theoretical evidence for the semi-insulating character of AlN
No full textWe present ab initio density-functional calculations for acceptors, donors, and native defects in aluminum nitride, showing that acceptors are deeper (Be similar to 0.25 eV, Mg similar to 0.45 eV) and less soluble than in GaN; at further variance with GaN, both the extrinsic donors Si-Al and C-Al, and the native donor V-N (the anion vacancy) are found to be deep (about 1 to 3 eV below the conduction). We thus predict that doped AlN will generally turn out to be semi-insulating in the normally achieved Al-rich conditions, in agreement with the known doping difficulties of high-x AlxGa1-xN alloys
Viral hepatitis and drugs: A continuing problem
No full textA seroepidemiological survey of a group of drug abusers has been carried out to determine the prevalence of hepatitis C virus and hepatitis B virus, hepatitis D virus, hepatitis A virus infection markers in sera, as well as to evaluate the role of potential risk factors. A total of 645 symptomless subjects with a history of injecting heroin were recruited as volunteers from methadone maintenance centres in Rome. For all hepatitis viruses the total figures showed high prevalence rates giving considerable viral circulation in this group. Among heroin addicts the prevalence was 63.4% for HCV, 65% for HBV, 13.3% for HDV and 50.9% for HAV. Anti-HCV prevalence correlated with serological evidence of HBV infection. A significant correlation was also found between presence of HCV antibodies and exposure time to drug addiction >5 years earlier. The data reveal the important role played by needle sharing in the spreading of multiple infections among intravenous drug abusers (IVDA). © 1993 International Epidemiological Association
Fast implementation of iterative adaptive approach for wideband unambiguous radar detection
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
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