999 resultados para 118-735
Resumo:
SeaBeam echo sounding, seismic reflection, magnetics, and gravity profiles were run along closely spaced tracks (5 km) parallel to the Atlantis II Fracture Zone on the Southwest Indian Ridge, giving 80% bathymetric coverage of a 30- * 170-nmi strip centered over the fracture zone. The southern and northern rift valleys of the ridge were clearly defined and offset north-south by 199 km. The rift valleys are typical of those found elsewhere on the Southwest Indian Ridge, with relief of more than 2200 m and widths from 22 to 38 km. The ridge-transform intersections are marked by deep nodal basins lying on the transform side of the neovolcanic zone that defines the present-day spreading axis. The walls of the transform generally are steep (25°-40°), although locally, they can be more subdued. The deepest point in the transform is 6480 m in the southern nodal basin, and the shallowest is an uplifted wave-cut terrace that exposes plutonic rocks from the deepest layer of the ocean crust at 700 m. The transform valley is bisected by a 1.5-km-high median tectonic ridge that extends from the northern ridge-transform intersection to the midpoint of the active transform. The seismic survey showed that the floor of the transform contains up to 0.5 km of sediment. Piston-coring at two locations on the transform floor recovered more than 1 m of sand and gravel, which appears to be turbidites shed from the walls of the fracture zone. Extensive dredging showed that more than two-thirds of the crust exposed in the transform valley and its walls were plutonic rocks, principally gabbros and residual mantle peridotites. In contrast, based on dredging and seafloor morphology, only relatively undisrupted pillow basalt flows have been exposed on crust of the same age spreading away from the transform. Magnetic anomalies are well defined out to 11 m.y. over the flanking transverse ridges and transform valley, even where layer 2 appears to be absent. The total opening rate is 1.6 cm/yr, but the arrangement of the anomalies indicates that the spreading for each ridge is asymmetric, with the ridge flanks facing the transform spreading at a rate of 1.0 cm/yr. Such an asymmetric spreading pattern requires that both the northern and southern ridges migrate away from each other at 0.2 cm/yr, thus lengthening the transform at 0.4 cm/yr for the last 11 m.y. To the north, the fracture zone valley is oriented differently from the present-day transform, indicating a paleospreading direction change at 17 m.y. from N10°E to due north-south. This change placed the transform into extension for the 11-m.y. period required for simple orthogonal ridge-transform geometry to be reestablished and produced a large transtensional basin within the transform valley. This basin was split by continued transform slip after 11 m.y., with the larger half moving to the north with the African Plate.
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Gabbroic rocks and their late differentiates recovered at Site 735 represent 500 m of oceanic layer 3. The original cooling of a mid-ocean ridge magma chamber, its penetration by ductile shear zones and late intrusives, and the subsequent penetration of seawater through a network of cracks and into highly permeable magmatic hydrofracture horizons are recorded in the metamorphic stratigraphy of the core. Ductile shear zones are characterized by extensive dynamic recrystallization of primary phases, beginning in the granulite facies and continuing into the lower amphibolite facies. Increasing availability of seawater during dynamic recrystallization is reflected in depletions in 18O, increasing abundance of amphibole of variable composition and metamorphic plagioclase of intermediate composition, and more complete coronitic or pseudomorphous static replacement of magmatic minerals. Downcore correlation of synkinematic assemblages, bulk-rock oxygen isotopic compositions, and vein abundance suggest that seawater is introduced into the crust by way of small cracks and veins that mark the end of the ductile phase of deformation. This "deformation-enhanced" metamorphism dominates the upper 180 and the lower 100 m of the core. In the lower 300 m of the core, mineral assemblages of greenschist and zeolite facies are abundant within or adjacent to brecciated zones. Leucocratic veins found in these zones and adjacent host rock contain diopside, sodic plagioclase, epidote, chlorite, analcime, thomsonite, natrolite, albite, quartz, actinolite, sphene, brookite, and sulfides. The presence of zircon, Cl-apatite, sodic plagioclase, sulfides, and diopside in leucocratic veins having local magmatic textures suggests that some of the veins originated from late magmas or from hydrothermal fluids exsolved from such magmas that were subsequently replaced by (seawater-derived) hydrothermal assemblages. The frequent association of these late magmatic intrusive rocks within the brecciated zones suggests that they are both artifacts of magmatic hydrofracture. Such catastrophic fracture and hydrothermal circulation could produce episodic venting of hydrothermal fluids as well as the incorporation of a magmatically derived hydrothermal component. The enhanced permeability of the brecciated zones produced lower temperature assemblages because of larger volumes of seawater that penetrated the crust. The last fractures were sealed either by these hydrothermal minerals or by late carbonate-smectite veins, resulting in the observed low permeability of the core.
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This paper reports a Scanning Electron Microscopy study of some samples from the leg 12, Deep Sea Drilling Project, sites 118 and 119. The chronostratigraphic distribution, the frequency of the species identified and the datation of the samples studied are presented. In accordance with the calcareous nannofossil zonation proposed by E. MARTINI (1971) the samples from site 118 are ascribed to the Upper Miocene while the samples from site 119 are located between the Lower (NN1) and the Upper Miocene (NN10).
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This paper reports a Scanning Electron Microscopy study of some samples from the leg 12, Deep Sea Drilling Project, sites 118 and 119. The chronostratigraphic distribution, the frequency of the species identified and the datation of the samples studied are presented. In accordance with the calcareous nannofossil zonation proposed by E. MARTINI (1971) the samples from site 118 are ascribed to the Upper Miocene while the samples from site 119 are located between the Lower (NN1) and the Upper Miocene (NN10).
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Ciências Musicais (ramo de Musicologia Histórica).
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BACKGROUND: Menarche and menopause mark the onset and cessation, respectively, of ovarian activity associated with reproduction, and affect breast cancer risk. Our aim was to assess the strengths of their effects and determine whether they depend on characteristics of the tumours or the affected women. METHODS: Individual data from 117 epidemiological studies, including 118 964 women with invasive breast cancer and 306 091 without the disease, none of whom had used menopausal hormone therapy, were included in the analyses. We calculated adjusted relative risks (RRs) associated with menarche and menopause for breast cancer overall, and by tumour histology and by oestrogen receptor expression. FINDINGS: Breast cancer risk increased by a factor of 1·050 (95% CI 1·044-1·057; p<0·0001) for every year younger at menarche, and independently by a smaller amount (1·029, 1·025-1·032; p<0·0001), for every year older at menopause. Premenopausal women had a greater risk of breast cancer than postmenopausal women of an identical age (RR at age 45-54 years 1·43, 1·33-1·52, p<0·001). All three of these associations were attenuated by increasing adiposity among postmenopausal women, but did not vary materially by women's year of birth, ethnic origin, childbearing history, smoking, alcohol consumption, or hormonal contraceptive use. All three associations were stronger for lobular than for ductal tumours (p<0·006 for each comparison). The effect of menopause in women of an identical age and trends by age at menopause were stronger for oestrogen receptor-positive disease than for oestrogen receptor-negative disease (p<0·01 for both comparisons). INTERPRETATION: The effects of menarche and menopause on breast cancer risk might not be acting merely by lengthening women's total number of reproductive years. Endogenous ovarian hormones are more relevant for oestrogen receptor-positive disease than for oestrogen receptor-negative disease and for lobular than for ductal tumours. FUNDING: Cancer Research UK.
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The purpose of this study was to assess the long-term outcomes of patients with polyarteritis nodosa (PAN) or microscopic polyangiitis (MPA) without Five-Factor Score (FFS)-defined poor-prognosis factors (FFS=0) and enrolled in a prospective clinical trial. Patients were followed (2005-2012) under routine clinical care in an extended study and data were recorded prospectively. Long-term survival, disease-free survival (DFS), relapses, therapeutic responses and sequelae were analyzed. Mean±SD follow-up was 98.2±41.9months. After having initially received glucocorticoids (GC) alone, according to the study protocol, 82% (97/118) patients achieved remission but 18% (21/118) required ≥1 immunosuppressant(s) (IS) before 19/21 achieved remission. Two patients died before entering remission. After remission, 53% (61/116) patients relapsed 25.6±27.9months after starting treatment. The 5- and 8-year overall survival rates were 93% and 86%, respectively, with no difference between PAN and MPA, and between relapsers and nonrelapsers. DFS was shorter for MPA than PAN patients (P=0.02). Throughout follow-up, 47% of patients required ≥1 IS. At the last follow-up visit, 44% were still taking GC and 15% IS. The mean vasculitis damage index score was 1.9±1.9; the most frequent sequelae were peripheral neuropathy, hypertension and osteoporosis. For PAN or MPA patients without poor-prognosis factors at diagnosis and treated initially with GC alone, long-term survival was excellent. However, relapses remained frequent, requiring IS introduction for nearly half of the patients. To lower the frequencies of relapses and sequelae remains a challenge for FFS=0 PAN and MPA patients.
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OBJECTIVES: To assess the prevalence and correlates of childhood and adolescent sexual and/or physical abuse (SPA) in bipolar I disorder (BDI) patients treated for a first episode of psychotic mania. METHODS: The Early Psychosis Prevention and Intervention Centre admitted 786 first-episode psychosis patients between 1998 and 2000. Data were collected from patients' files using a standardized questionnaire. A total of 704 files were available; 43 were excluded because of a nonpsychotic diagnosis at endpoint and 3 due to missing data regarding past stressful events. Among 658 patients with available data, 118 received a final diagnosis of BDI and were entered in this study. RESULTS: A total of 80% of patients had been exposed to stressful life events during childhood and adolescence and 24.9% to SPA; in particular, 29.8% of female patients had been exposed to sexual abuse. Patients who were exposed to SPA had poorer premorbid functioning, higher rates of forensic history, were less likely to live with family during treatment period, and were more likely to disengage from treatment. CONCLUSIONS: SPA is highly prevalent in BDI patients presenting with a first episode of psychotic mania; exposed patients have lower premorbid functional levels and poorer engagement with treatment. The context in which such traumas occur must be explored in order to determine whether early intervention strategies may contribute to diminish their prevalence. Specific psychological interventions must also be developed.
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Au commt on a ajouté des vers sur Jonas, etc.
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The purpose of this study was to assess the outcomes of 118 patients with eosinophilic granulomatosis with polyangiitis (EGPA) enrolled in 2 prospective, randomized, open-label clinical trials (1994-2005), with or without Five-Factor Score (FFS)-defined poor-prognosis factors, focusing on survival, disease-free survival, relapses, clinical and laboratory findings, therapeutic responses, and factors predictive of relapse. Forty-four patients with FFS ≥ 1 were assigned to receive 6 or 12 cyclophosphamide pulses plus corticosteroids and the seventy-four with FFS = 0 received corticosteroids alone, with immunosuppressant adjunction when corticosteroids failed. Patients were followed (2005-2011) under routine clinical care in an extended study and data were recorded prospectively. Mean ± SD follow-up was 81.3 ± 39.6 months. Among the 118 patients studied, 29% achieved long-term remission and 10% died. Among the 115 patients achieving a first remission, 41% experienced ≥1 relapses, 26.1 ± 26.8 months after treatment onset, with 57% of relapses occurring when corticosteroid-tapering reached <10 mg/day. Treatment achieved new remissions in >90%, but relapses recurred in 38%. Overall survival was good, reaching 90% at 7 years, regardless of baseline severity. Age ≥65 years was the only factor associated with a higher risk of death during follow-up. The risk of relapse was higher for patients with anti-myeloperoxidase antibodies and lower for those with >3000 eosinophils/mm(3). Sequelae remained frequent, usually chronic asthma and peripheral neuropathy. In conclusion, EGPA patients' survival rate is very good when treatment is stratified according to the baseline FFS. Relapses are frequent, especially in patients with anti-myeloperoxidase antibodies and baseline eosinophilia <3000/mm(3).