1000 resultados para 74-529


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Volcaniclastic rocks of Late Cretaceous age occur in four out of five sites (525, 527, 528, 529) drilled on the crest and the northwest flank of the Walvis Ridge during Leg 74. They are mostly interlayered with and overlie basement in the lowermost 10-100 m of the sedimentary section. Rocks from Holes 525A and 528 were studied megascopically and microscopically, by XRD, and XRF chemical analyses of whole-rock major and trace elements were undertaken. The dominant rock of Hole 528 volcaniclastics is a fine-grained (silt to fine sand), mostly matrix-bearing (partly matrix-rich) vitric "tuff," occurring as 5-110 cm thick, partly graded layers, some of which are distinctly bedded. Volcaniclastics of Hole 525A are generally richer in sanidine crystals. Most rocks contain some nonvolcanic clasts, chiefly foraminifers and lesser amounts of shallow-water fossil debris. Scoria shards, clasts of tachylite, and fine-grained basalts as well as chemical analyses suggest a basaltic to intermediate composition for most rocks of Hole 528, whereas volcaniclastics of Hole 525A are more silicic. The occurrence of tachylite and epiclastic, coarse-grained, basaltic clasts throughout the volcaniclastic sequence at Site 528 indicates shallow-water eruptions and perhaps even ocean island volcanism. The minor occurrence in Hole 528 of trachytic? pumice shards with phenocrysts of K-feldspar and the abundance of such shards in rocks from Hole 525A indicate Plinian eruptions characteristic of more mature stages of ocean island evolution. The sedimentary structures of volcaniclastic layers and their occurrence within deep sea calcareous oozes indicate a mass flow origin. Diagenetic alteration of the volcaniclastic rocks is pronounced, and four major stages of glass shard alteration are distinguished. Despite the effects of alteration and small-scale redistribution of elements and the admixture of nonvolcanic components, there were no drastic changes in the chemical composition of the rocks, except for pronounced increases in K and Rb and decreases in Ca and Fe. The basaltic volcaniclastic rocks very much resemble basement basalts in that they are moderately evolved tholeiites derived from an LIL-enriched mantle source with Zr/Nb ratios (Hole 528) of 5 to 6. This, in conjunction with the interbedding of volcaniclastic rocks and basement lavas, indicates contemporaneous seamount or island and basement volcanic activity involving magmas derived from similar sources.

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We examined differences in response latencies obtained during a validated video-based hazard perception driving test between three healthy, community-dwelling groups: 22 mid-aged (35-55 years), 34 young-old (65-74 years), and 23 old-old (75-84 years) current drivers, matched for gender, education level, and vocabulary. We found no significant difference in performance between mid-aged and young-old groups, but the old-old group was significantly slower than the other two groups. The differences between the old-old group and the other groups combined were independently mediated by useful field of view (UFOV), contrast sensitivity, and simple reaction time measures. Given that hazard perception latency has been linked with increased crash risk, these results are consistent with the idea that increased crash risk in older adults could be a function of poorer hazard perception, though this decline does not appear to manifest until age 75+ in healthy drivers.

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The osteogenic potential of human adipose-derived precursor cells seeded on medical-grade polycaprolactone-tricalcium phosphate scaffolds was investigated in this in vivo study. Three study groups were investigated: (1) induced—stimulated with osteogenic factors only after seeding into scaffold; (2) preinduced—induced for 2 weeks before seeding into scaffolds; and (3) uninduced—cells without any introduced induction. For all groups, scaffolds were implanted subcutaneously into the dorsum of athymic rats. The scaffold/cell constructs were harvested at the end of 6 or 12 weeks and analyzed for osteogenesis. Gross morphological examination using scanning electron microscopy indicated good integration of host tissue with scaffold/cell constructs and extensive tissue infiltration into the scaffold interior. Alizarin Red histology and immunostaining showed a heightened level of mineralization and an increase in osteonectin, osteopontin, and collagen type I protein expression in both the induced and preinduced groups compared with the uninduced groups. However, no significant differences were observed in these indicators when compared between the induced and preinduced groups.

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Background Little information exists regarding the interaction effects of obesity with long-term air pollution exposure on cardiovascular diseases (CVDs) and stroke in areas of high pollution. The aim of the present study is to examine whether obesity modifies CVD-related associations among people living in an industrial province of northeast China. Methods We studied 24,845 Chinese adults, aged 18 to 74 years old, from three Northeastern Chinese cities in 2009 utilizing a cross-sectional study design. Body weight and height were measured by trained observers. Overweight and obesity were defined as a body mass index (BMI) between 25–29.9 and ≥ 30 kg/m2, respectively. Prevalence rate and related risk factors of cardiovascular and cerebrovascular diseases were investigated by a questionnaire. Three-year (2006–2008) average concentrations of particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), and ozone (O3) were measured by fixed monitoring stations. All the participants lived within 1 km of air monitoring sites. Two-level logistic regression (personal level and district-specific pollutant level) was used to examine these effects, controlling for covariates. Results We observed significant interactions between exposure and obesity on CVDs and stroke. The associations between annual pollutant concentrations and CVDs and stroke were strongest in obese subjects (OR 1.15–1.47 for stroke, 1.33–1.59 for CVDs), less strong in overweight subjects (OR 1.22–1.35 for stroke, 1.07–1.13 for CVDs), and weakest in normal weight subjects (OR ranged from 0.98–1.01 for stroke, 0.93–1.15 for CVDs). When stratified by gender, these interactions were significant only in women. Conclusions Study findings indicate that being overweight and obese may enhance the effects of air pollution on the prevalence of CVDs and stroke in Northeastern metropolitan China. Further studies will be needed to investigate the temporality of BMI relative to exposure and onset of disease.

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The influence of chemical mutation featuring the selective conversion of asparagine or glutamine to aspartic or glutamic acid, respectively, on the kinetics of refolding of reduced RNase has been studied. The monodeamidated derivatives of RNase A, viz. RNase Aa1a, Aa1b, and Aa1c having their deamidations in the region 67-74, were found to regain nearly their original enzymatic activity. However, a marked difference in the kinetics of refolding is seen, the order of regain of enzymic activity being RNase A greater than Aa1c congruent to Aa1a greater than Aa1b. The similarities in the distinct elution positions on Amberlite XE-64, gel electrophoretic mobilities, and u.v. spectra of reoxidized and native derivatives indicated that the native structures are formed. The slower rate of reappearance of enzymic activity in the case of the monodeamidated derivatives appears to result from altered interactions in the early stages of refolding. The roles of some amino acid residues of the 67-74 region in the pathway of refolding of RNase A are discussed.

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The synthesis, X-ray crystal structure, and magnetic properties of an angular trinuclear copper(II) complex [Cu3(O2CMC)4(bpy)3(H2O)](PF6)2 (1), obtained from a reaction of Cu2(O2CMe)4(H2O)2 With 2,2'-bipyridine (bpy) and NH4PF6 in ethanol, are reported. Complex 1 crystallizes in triclinic space group P1BAR with a = 11.529(1) angstrom, b = 12.121(2) angstrom, c = 17.153(2) angstrom, alpha = 82.01(1)-degrees, beta = 79.42(1)-degrees, gamma = 89.62(1)-degrees, and Z = 2. A total of 6928 data with I > 2.5sigma(I) were refined to R = 0.0441 and R(w) = 0.0557. The structure consists of a trinuclear core bridged by four acetate ligands showing different bonding modes. The coordination geometry at each copper is distorted square-pyramidal with a CuN2O2...O chromophore. The Cu...Cu distances are 3.198(1) angstrom, 4.568(1) angstrom, and 6.277(1) angstrom. There are two monoatomic acetate bridges showing Cu-O-Cu angles of 93.1(1) and 97.5(1)-degrees. Magnetic studies in the temperature range 39-297 K show the presence of a strong ferromagnetically coupled dicopper(II) unit (2J = +158 cm-1) and an essentially isolated copper(II) center (2J' = -0.4 cm-1) in 1. The EPR spectra display an axial spectrum giving g(parallel-to) = 2.28 (A(parallel-to) = 160 X 10(-4) cm-1) and g(perpendicular-to) = 2.06 (A(perpendicular-to) = 12 X 10(-4) cm-1) for the normal copper and two intense isotropic signals with g values 2.70 and 1.74 for the strongly coupled copper pair. The structural features of 1 compare well with the first generation models for ascorbate oxidase.

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Resumen: El artículo considera los derechos y deberes de médicos y pacientes, especialmente luego de la sanción de la ley 26.529, destacando sus temas relevantes, aquellos que habían dado lugar a distintas interpretaciones tanto en la jurisprudencia, como en la doctrina. Se tratan, así, la historia clínica y el consentimiento informado, precisándose sus conceptos, formas, funciones e interpretaciones. Similar atención merecen las directivas anticipadas de salud, el “testamento vital”, las posibilidades del médico y sus posibles objeciones de conciencia. De igual modo la autonomía de la voluntad del paciente, su libertad y responsabilidad. Se considera la eutanasia, precisándose que no es un derecho del paciente. Se estudia el secreto profesional del médico, a la luz de las contradictorias normas legales vigentes y jurisprudencia consecuente, para detenerse en la más reciente decisión de la Corte Suprema de Justicia de la Nación en su actual composición. Finalmente se precisan los conceptos de las responsabilidades de médicos y órganos sanitarios, con la posibilidad de su aseguramiento y el conflicto de algunas de las coberturas que se otorgan en plaza, como la conocida claims made.

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Começa a votação do título VII, que trata da Ordem Econômica. Constituintes se reúnem para organizar e discutir os acordos sobre os temas polêmicos da Ordem Econômica e Financeira. A definição de empresa nacional, a reforma agrária, a reforma urbana e a distribuição de derivados de petróleo são os temas polêmicos que estão neste título.. O uso do subsolo é também um tema polêmico. A Frente Parlamentar Nacional está preocupada com a forma em que será votado esse tema. Parlamentares discutem como será ocupado o solo urbano.

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A small stream in the French Alps was sampled at regular intervals to determine the size distribution of animals for growth studies. The temperature was also measured. The results obtained for Gammarus fossarum were compared with laboratory cultures and the laboratory animals were physiologically and chemically analysed. Chemical analysis was also carried out on field animals.

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To ascertain the effect of various concentrations of oxygen in water on the fry of rainbow trout experiments were made with aquaria at various concentrations of oxygen. The food supplied was chironomid larvae (Chironomus plumosus). A surplus of food was supplied to the fry. Indices are given of the reaction of the fry to different temperatures.