903 resultados para confined
Resumo:
Empirical studies on the impact of women’s paid jobs on their empowerment and welfare in the Bangladesh context are rare. The few studies on the issue to date have all been confined to the garment workers only although studies indicate that women’s workforce participation in Bangladesh has increased across-the-board. Besides, none of these studies has made an attempt to control for the non-working women and/or applied any statistical technique to control for the effects of other pertinent determinants of women’s empowerment and welfare such as education, age, religion and place of living. This study overcomes these drawbacks and presents alternative assessments of the link between women’s workforce participation and empowerment on the basis of survey data from the two largest cities in Bangladesh. While the generic assessment indicates that women’s paid jobs have positive implications for women’s participation in decisions on fertility, children’s education and healthcare as well as their possession and control of resources, the econometric assessment negates most of these observations. Women’s education, on the other hand, appears to be more important than their participation in the labour force. The study underlines the fact that by omitting other relevant explanatory variables from the analysis, the previous studies might have overestimated the impact of women’s paid work on their empowerment. Among other things, the paper also highlights the importance of women’s job category, religion and regional differences for women’s empowerment.
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Non-periodic structural variation has been found in the high T-c cuprates, YBa2Cu3O7-x and Hg0.67Pb0.33Ba2Ca2Cu3O8+delta, by image analysis of high resolution transmission electron microscope (HRTEM) images. We use two methods for analysis of the HRTEM images. The first method is a means for measuring the bending of lattice fringes at twin planes. The second method is a low-pass filter technique which enhances information contained by diffuse-scattered electrons and reveals what appears to be an interference effect between domains of differing lattice parameter in the top and bottom of the thin foil. We believe that these methods of image analysis could be usefully applied to the many thousands of HRTEM images that have been collected by other workers in the high temperature superconductor field. This work provides direct structural evidence for phase separation in high T-c cuprates, and gives support to recent stripes models that have been proposed to explain various angle resolved photoelectron spectroscopy and nuclear magnetic resonance data. We believe that the structural variation is a response to an opening of an electronic solubility gap where holes are not uniformly distributed in the material but are confined to metallic stripes. Optimum doping may occur as a consequence of the diffuse boundaries between stripes which arise from spinodal decomposition. Theoretical ideas about the high T-c cuprates which treat the cuprates as homogeneous may need to be modified in order to take account of this type of structural variation.
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The changing incidence of adenocarcinomas, particularly in the oesophagus and gastric cardia, has led to the rapid expansion of screening programmes aimed at detecting the precursor lesion of dysplasia before adenocarcinoma develops. The pathologist now has an important role in first diagnosing patients at risk for developing dysplasia, and then correctly classifying dysplasia when it occurs. Barrett's oesophagus has had different diagnostic criteria in previous years but is currently diagnosed by the presence of intestinal metaplasia of any length in the true oesophagus. Intestinal metaplasia confined only to the gastro-oesophageal junction or cardia is of uncertain significance but is probably common, with less risk of progressing to dysplasia or malignancy. In the stomach, patients with autoimmune atrophic gastritis and Helicobacter-associated multifocal atrophic gastritis have an increased risk of adenocarcinoma, but screening protocols are not well-developed compared with those used for Barrett's oesophagus. Dysplasia of glandular epithelium can be classified using well-described criteria. Low grade dysplasia is the most common type and regresses or remains stable in the majority of patients. High grade dysplasia is more ominous clinically, with a propensity to coexist with or progress to adenocarcinoma.
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OBJECTIVES We developed a prognostic strategy for quantifying the long-term risk of coronary heart disease (CHD) events in survivors of acute coronary syndromes (ACS). BACKGROUND Strategies for quantifying long-term risk of CHD events have generally been confined to primary prevention settings. The Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) study, which demonstrated that pravastatin reduces CHD events in ACS survivors with a broad range of cholesterol levels, enabled assessment of long-term prognosis in a secondary prevention setting. METHODS Based on outcomes in 8,557 patients in the LIPID study, a multivariate risk factor model was developed for prediction of CHD death or nonfatal myocardial infarction. Prognostic indexes were developed based on the model, and low-, medium-, high- and very high-risk groups were defined by categorizing the prognostic indexes. RESULTS In addition to pravastatin treatment, the independently significant risk factors included: total and high density lipoprotein cholesterol, age, gender, smoking status, qualifying ACS, prior coronary revascularization, diabetes mellitus, hypertension and prior stroke. Pravastatin reduced coronary event rates in each risk level, and the relative risk reduction did not vary significantly between risk levels. The predicted five-year coronary event rates ranged from 5% to 19% for those assigned pravastatin and from 6.4% to 23.6% fur those assigned placebo. CONCLUSIONS Long-term prognosis of ACS survivors varied substantially according to conventional risk factor profile. Pravastatin reduced coronary risk within all risk levels; however, absolute risk remained high in treated patients with unfavorable profiles. Our risk stratification strategy enables identification of ACS survivors who remain at very high risk despite statin therapy. CT Am Coil Cardiol 2001;38:56-63) (C) 2001 by the American College of Cardiology.
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When visual information is confined to one object plane, the emmetropization end-point is adjusted in accord with the corresponding incident optical vergence at the eye [Proceedings of the 7th International Conference on Myopia (2000) 113]. We now report the effect of adding extra visual information beyond the target plane. Visual conditions were controlled using a cone-lens system: black Maltese cross targets on white opaque backgrounds (OMX) were attached to the open faces of 2.5 cm translucent cones fitted with either 0, +25 or +40 D imaging lenses. An alternative target (TMX) was made by substituting the opaque target background for a transparent background, which allowed access to visual information beyond the target plane. The imaging devices were applied to 7-day-old chicks and worn for 4 days. Prior to this treatment, on day 2, some chicks underwent ciliary nerve section (CNS) to preclude accommodation. All treatments were monocular. Refractive errors and axial ocular dimensions were measured using retinoscopy and A-scan ultrasonography under halothane anesthesia. Treatment effects were specified as mean ( +/-S.D.) interocular differences. Eyes with the OMX/ + 40 D lens combination remained emmetropic ( +0.73 +/-3.57 D), consistent with the target plane being approximately conjugate with the retina. Switching to the TMX caused a hyperopic shift in refractive error ( + 3.78 +/- 3.41 D). This relative shift towards hyperopia in switching from the OMX to the TMX target also occurred for the other two lens powers. Thus, the OMX/ + 25 D lens induced myopia ( - 7.00 +/-5.88 D), corresponding to the imposed hyperopic defocus (target plane now imaged behind the retina), and switching to the TMX resulted in a reduction in myopia (-1.73 +/-5.36 D), The OMX/0 D lens combination produced the largest myopic shift, and here, switching to the TMX condition almost eliminated the myopic response (-15.50 +/-6.62 D cf. -0.56 +/-1.24 D). This relative hyperopic shift associated with switching from the OMX to the TMX target was eliminated by CNS surgery. Thus, the two CNS/TMX groups were both more myopic than the equivalent no CNS/TMX groups ( + 40 D lens: -2.66 +/-2.34 D; +25 D lens: -7.97 +/-6.87 D). When the visual information is restricted to one plane, incident optical vergence appears to direct emmetropization. Adding Visual information at other distances produces a shift in the end-point of ernmetropization in the direction of the added information. That these effects are dependent on the integrity of the accommodation system implies that accommodation plays a role in emmetropization and represents the first reported evidence of this kind. Published by Elsevier Science Ltd.
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We report on a proof of principle demonstration of an optically driven micromachine element. Optical angular momentum is transferred from a circularly polarized laser beam to a birefringent particle confined in an optical tweezers trap. The optical torque causes the particle to spin at up to 350 Hz, and this torque is harnessed to drive an optically trapped microfabricated structure. We describe a photolithographic method for producing the microstructures and show how a light driven motor could be used in a micromachine system. (C) 2001 American Institute of Physics.
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A new method of measuring heat of desorption is proposed in this Letter. The principle of the method is to measure the amount of mass released when a controlled amount of energy is supplied directly to a solid adsorbent. This is in contrast to conventional methods such as microcalorimetry, where heat released upon adsorption is measured. In this method, a quantified heat supply is generated by passing a de current through a carbon pellet, which is equilibrated with a gas phase confined in a closed vessel. As a consequence of the heating, the particle temperature is increased, resulting in partial desorption of adsorbed molecules. The variations of pellet temperature and the system pressure with respect to time are used to determine the heat of desorption as a function of loading.
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During the Middle Jurassic, the regional environment of Curio Bay, southeast South Island, New Zealand, was a fluvial plain marginal to volcanic uplands. Intermittent flashy, poorly-confined flood events buried successive conifer forests. With the termination of each flood, soils developed and vegetation was reestablished. In most cases, this developed into coniferous forest. In approximately 40 m of vertical section, 10 fossil forest horizons can be distinguished, highlighting a type of fluvial architecture which is poorly documented. Flood-basin material is minimal, but a short-Lived floodbasin lake is inferred to have developed within the interval of study. Paleocurrent indicators suggest enclosure of the basin on more than one side. Sedimentation style suggests a relatively dry (less than humid but not arid) climate with seasonal rainfall. (C) 2001 Elsevier Science B.V. All rights reserved.
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Trace elements can have a significant effect on the processing and properties of aluminium alloys, including sintered alloys. As little as 0.07 wt% (100 ppm) lead, tin or indium promotes sintering in an Al-Zn-Mg-Cu alloy produced from mixed elemental powders. This is a liquid phase sintering system and thin liquid films form uniformly throughout the alloy in the presence of the trace elements, but liquid pools develop in their absence. Analytical transmission electron microscopy indicates that the trace elements are confined to the interparticle and grain boundary regions. The sintering enhancement is attributed to the segregation of the microalloying addition to the liquid-vapour interface. Because the microalloying elements have a low surface tension, they lower the effective surface tension of the liquid. This reduces the wetting angle and extends the spreading of the liquid through the matrix. An improvement in sintering results. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
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In situ gelatin zymography is a simple technique providing valuable information about the cellular and tissue localization of gelatinases. Until recently, the use of this technique has been confined to soft, relatively homogeneous tissue. In this report in situ zymography has been utilized to assess the sub-lamellar location of gelatinases in the hard, semi-keratinized epidermal layer and the adjacent soft connective tissue matrix of the dermis of the equine hoof. We show that alterations in the orientation at which the tissue is dipped and withdrawn from the emulsion cause profound alterations in emulsion thickness. Microscopic Variations in the surface topography of frozen tissue sections also influence emulsion thickness making interpretation of the results difficult. Given these results, researchers must be aware of potential variations in zymographic analysis may be influenced by physical tissue parameters in addition to suspected gelatinase activity. (C) 2001 Elsevier Science B.V. All rights reserved.
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A theory is developed for calculating the entrapment of particles by a windbreak, with four results. (1) The fraction of particles in the oncoming flow which pass through the windbreak, or transmittance of the windbreak for particles (sigma), is related to the optical porosity (tau). The very simple approximation sigma=tau works well for most applications involving the interception of spray droplets by windbreaks. Results from a field experiment agree with the theoretical predictions. (2) A new equation for the bulk drag coefficient of a windbreak is tested against numerical, wind tunnel and field experiments. This enables the bleed velocity for the flow through the windbreak to be predicted in terms of the screen pressure coefficient (k) of the barrier. (3) The relationship between k and tau is different for a vegetative barrier than for a screen across a confined duct, implying a lower Fc for given tau. (4) The total deposition of particles to a windbreak is determined by a trade-off between particle absorption and throughflow, implying an optimum value of tau for maximum total deposition. For particles larger than 30 mum and vegetation elements smaller than 30 mm, this occurs near tau = 0.2. (C) 2001 Elsevier Science Ltd. All rights reserved.
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Smooth muscle cells (SMC) exhibit a functional plasticity, modulating from the mature phenotype in which the primary function is contraction, to a less differentiated state with increased capacities for motility, protein synthesis, and proliferation. The present study determined, using Western analysis, double-label immunofluorescence and confocal microscopy, whether changes in phenotypic expression of rabbit aortic SMC in culture could be correlated with alterations in expression and distribution of structural proteins. Contractile state SMC (days 1 and 3 of primary culture) showed distinct sorting of proteins into subcellular domains, consistent with the theory that the SMC structural machinery is compartmentalised within the cell. Proteins specialised for contraction (alpha -SM actin, SM-MHC, and calponin) were highly expressed in these cells and concentrated in the upper central region of the cell. Vimentin was confined to the body of the cell, providing support for the contractile apparatus but not co-localising with it. In line with its role in cell attachment and motility, beta -NM actin was localised to the cell periphery and basal cortex. The dense body protein alpha -actinin was concentrated at the cell periphery, possibly stabilising both contractile and motile apparatus. Vinculin-containing focal adhesions were well developed, indicating the cells' strong adhesion to substrate. In synthetic state SMC (passages 2-3 of culture), there was decreased expression of contractile and adhesion (vinculin) proteins with a concomitant increase in cytoskeletal proteins (beta -non-muscle [NM] actin and vimentin). These quantitative changes in structural proteins were associated with dramatic chan-es in their distribution. The distinct compartmentalisation of structural proteins observed in contractile state SMC was no longer obvious, with proteins more evenly distributed throughout die cytoplasm to accommodate altered cell function. Thus, SMC phenotypic modulation involves not only quantitative changes in contractile and cytoskeletal proteins, but also reorganisation of these proteins. Since the cytoskeleton acts as a spatial regulator of intracellular signalling, reorganisation of the cytoskeleton may lead to realignment of signalling molecules, which, in turn, may mediate the changes in function associated with SMC phenotypic modulation. (C) 2001 Wiley-Liss, Inc.
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OBJECTIVES Graves' disease (GD) complicates 0.1% to 0.2% of pregnancies, but congenital thyrotoxicosis is rare occurring in one in 70 of these pregnancies independent of maternal disease status. Antenatal prediction of affected infants is imprecise; however, maternal history, coupled with a high maternal serum TSH receptor binding immunoglobulin index (TBII) predict adverse neonatal outcome. Mortality is reported to be as high as 25% in affected infants and would therefore be expected to be higher in premature infants. This study illustrates that in sick, premature, extreme low birth weight (ELBW) or intrauterine growth retarded (IUGR) infants, the diagnosis maybe overlooked especially in the absence of antenatal risk assessment and management of thyrotoxicosis in this setting is complex. DESIGN and PATIENTS The records of premature neonates born at the three main maternity units in Brisbane, between January 1996 and July 1998 diagnosed with congenital thyrotoxicosis were reviewed. Data were recorded on gestational age, birth weight (B Wt), maternal thyroid history and current status, and neonatal course. Thyroid function and TBII status was assessed using standard biochemical assays. RESULTS Seven neonates from five pregnancies were identified (four female, three male). Mean gestational age was 30 week (25-36 week) and median B Wt was 1.96 kg (0.50-2.62 kg). Only one mother received formal antenatal counselling by a paediatric endocrine service and had a TBII (54%) measured prior to delivery. Three of five mothers had elevated TBII measured after diagnosis in their offspring (57%, 65%, 83%) and in one mother, a TBII was not performed. All mothers were biochemically euthyroid at delivery. Mean age at diagnosis was 9 days (1-16 days) and mean age at commencement of treatment was 12 days (7-26 days). Two infants received propylthiouracil and five received a combination of carbimazole and propranolol. Pour became biochemically hypothyroid, in three this resolved with cessation of the antithyroid drug (ATD), and one required ongoing T4 supplementation. Only one infant required treatment for cardiac failure and there were no deaths in this cohort. CONCLUSIONS This is a large series of extremely small and premature infants with neonatal thyrotoxicosis. Presentation was nonspecific. The diagnosis was delayed because of low birth weight, prematurity, multiple birth and/or an unrecognized maternal history of Graves' disease. The treatment of neonatal thyrotoxicosis was difficult in these extreme law birth weight infants yet no infant died and significant morbidity was confined to high output cardiac failure in one infant. With antenatal recognition of past or active Graves' disease, assessment of maternal TSH receptor binding immunoglobulin index prior to delivery and postnatal monitoring of cord TSH and venous fT4 and TSH on days 4 and 7 rapid treatment of affected infants may have further reduced neonatal morbidity.
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The Eph family of receptor tyrosine kinases and their ligands, the ephrins, are important regulators of axon guidance and cell migration in the developing nervous system. Inactivation of the EphA4 gene results in axon guidance defects of the corticospinal tract, a major descending motor pathway that originates in the cortex and terminates at all levels of the spinal cord. In this investigation, we report that although the initial development of the corticospinal projection is normal through the cortex, internal capsule, cerebral peduncle, and medulla in the brain of EphA4 deficient animals, corticospinal axons exhibit gross abnormalities when they enter the gray matter of the spinal cord. Notably, many corticospinal axons fail to remain confined to one side of the spinal cord during development and instead, aberrantly project across the midline, terminating ipsilateral to their cells of origin. Given the possible repulsive interactions between EphA4 and one of its ligands, ephrinB3, this defect could be consistent with a loss of responsiveness by corticospinal axons to ephrinB3 that is expressed at the spinal cord midline. Furthermore, we show that EphA4 deficient animals exhibit ventral displacement of the mature corticospinal termination pattern, suggesting that developing corticospinal axons, which may also express ephrinB3, fail to be repelled from areas of high EphA4 expression in the intermediate zone of the normal spinal cord. Taken together, these results suggest that the dual expression of EphA4 on corticospinal axons and also within the surrounding gray matter is very important for the correct development and termination of the corticospinal projection within the spinal cord. J. Comp. Neurol. 436: 248-262, 2001. (C) 2001 Wiley-Liss, Inc.
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Our studies on two branching mutants of pea (Pisum sativum L.) have identified a further Ramosus locus, Rms6, with two recessive or partially recessive mutant alleles: rms6-1 (type line S2-271) and rms6-2 (type line K586). Mutants rms6-1 and rms6-2 were derived from dwarf and tall cultivars, Solara and Torsdag, respectively. The rms6 mutants are characterized by increased branching from basal nodes. In contrast, mutants rms1 through rms5 have increased branching from both basal and aerial (upper stem) nodes. Buds at the cotyledonary node of wild-type (WT) plants remain dormant but in rms6 plants these buds were usually released from dormancy. Their growth was either subsequently inhibited, sometimes even prior to emergence above ground, or they grew into secondary stems. The mutant phenotype was strongest for rms6-1 on the dwarf background. Although rms6-2 had a weak single-mutant phenotype, the rms3-1 rms6-2 double mutant showed clear transgression and an additive branching phenotype, with a total lateral length almost 2-fold greater than rms3-1 and nearly 5-fold greater than rms6-2 . Grafting studies between WT and rms6-1 plants demonstrated the primary action of Rms6 may be confined to the shoot. Young WT and rms6-1 shoots had similar auxin levels, and decapitated plants had a similar magnitude of response to applied auxin. Abscisic acid levels were elevated 2-fold at node 2 of young rms6-1 plants. The Rms6 locus mapped to the R to Gp segment of linkage group V (chromosome 3). The rms6 mutants will be useful for basic research and also have possible agronomical value.