887 resultados para racial tension
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PURPOSE. To investigate in parallel the systemic glutathione levels of patients suffering from primary open angle glaucoma (POAG) or normal tension glaucoma (NTG) with comparable functional loss. METHODS. Thirty-four POAG patients, 30 NTG patients, and 53 controls were subjected to blood analysis to detect the level of circulating glutathione in its reduced (GSH) and oxidized (GSSG) forms. Systemic blood pressure (BP) and ocular perfusion pressure (OPP) parameters were also determined. RESULTS. Independent of age, POAG and NTG patients demonstrated significantly lower GSH and t-GSH levels than age-matched controls (P < 0.001). Additionally, a lower redox index was found, but in POAG patients only, in comparison to both NTG and control groups (P = 0.020). GSSG levels were, however, similar between all study groups (P > 0.05). CONCLUSIONS. This study demonstrates, for the first time, that both POAG and NTG patients exhibit lower GSH and t-GSH levels than age-matched controls, indicating a similar general compromise of the antioxidant defense systems may exist in both conditions. © 2013 The Association for Research in Vision and Ophthalmology, Inc.
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Purpose: To investigate the coexistence of ocular microvascular and systemic macrovascular abnormalities in early stage, newly diagnosed and previously untreated normal tension glaucoma patients (NTG). Methods: Retinal vascular reactivity to flickering light was assessed in 19 NTG and 28 age-matched controls by means of dynamic retinal vessel analysis (IMEDOS GmbH, Jena, Germany). Using a newly developed computational model, the entire dynamic vascular response profile to flicker light was imaged and used for analysis. In addition, assessments of carotid intima-media thickness (IMT) and pulse wave analysis (PWA) were conducted on all participants, along with blood pressure (BP) measurements and blood analyses for lipid metabolism markers. Results: Patients with NTG demonstrated an increased right and left carotid IMT (p = 0.015, p = 0.045) and an elevated PWA augmentation index (p = 0.017) in comparison with healthy controls, along with an enhanced retinal arterial constriction response (p = 0.028), a steeper retinal arterial constriction slope (p = 0.031) and a reduced retinal venous dilation response (p = 0.026) following flicker light stimulation. Conclusions: Early stage, newly diagnosed, NTG patients showed signs of subclinical vascular abnormalities at both macro- and micro-vascular levels, highlighting the need to consider multi-level circulation-related pathologies in the development and progression of this type of glaucoma.
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Objective: To compare and contrast the presence of ocular and systemic vascular function in newly diagnosed and previously untreated primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) patients with comparable, early stage, functional loss. Methods: The systemic vascular function of 19 POAG patients, 19 NTG patients and 20 healthy controls was assessed by means of 24 hour ambulatory blood pressure (ABPM), peripheral pulse wave analysis (PWA) and carotid intima-media thickness (IMT). Retinal vascular reactivity to flicker light was assessed using dynamic retinal vessel analysis (DVA,IMEDOS, GmbH, Jena, Germany). Results: When compared to normal controls, both POAG and NTG patients exhibited similarly increased nocturnal systemic blood pressure variability (p=0.011); peripheral arterial stiffness (p=0.015), carotid IMT (p=0.040) and reduced ocular perfusion pressure (OPP) (p<0.001). Furthermore, on DVA analysis, both groups of glaucoma patients also exhibited steeper retinal arterial constriction slopes (slope AC) following cessation of flicker (p=0.007) and a similarly increased fluctuation in arterial and venous baseline diameter (p=0.008 and p=0.009 respectively) in comparison to controls. Conclusion: POAG and NTG patients exhibit similar alterations in both ocular and systemic circulation at the early stages of their disease process. This highlights not only the importance of considering vascular risk factors in both conditions, but also raises questions about the current separation of the two conditions into completely distinct clinical entities.
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When exposed to high levels of strain, polymer optical fibre grating sensors recorded in poly(methyl methacrylate) based fibre often exhibit hysteresis in the response of their Bragg wavelength to strain. We demonstrate that the application of pre-tension and annealing of the polymer fibre can reduce this hysteresis when the fibre is suspended freely between two supports, but much better performance is obtained when the sensor is attached directly to a substrate. In this case, the hysteresis can be lessened by more than a factor of 12. © 2014 IOP Publishing Ltd.
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A study was made of notch effects on the cleavage fracture of polycrystalline zinc. It was seen that the nominal fracture stress of SENB specimens was independent of notch angle. The maximum tensile stress below the notch at fracture in SENB specimens was shown to be different from the tensile stress at fracture in tensile testpieces over a temperature range from −196 to −17°C. The notch root strain at fracture was found to be the same as the uniaxial tensile fracture strain over this temperature interval. These results were interpreted as showing the cleavage fracture of polycrystalline zinc to be shear-stress or initiation controlled, as predicted by Stroh's dislocation model of cleavage.
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This piece suggests that the field of ethnic and racial studies is too diverse in theoretical and methodological approach and subject of study to constitute its own discipline. Instead, ethnic and racial studies remains a loosely defined space of interdisciplinary exchange. There is a sense of community among researchers in this field, but teaching continues to be organized to meet the imperatives of different home disciplines. This article argues that in these times of increasing bureaucracy, standardization and managerial intrusion into academic life, there is a positive benefit in retaining a relatively open space of inquiry where we can consider the construction of contemporary social boundaries.
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This mixed-methods study examines the perceptions and opinions of United Kingdom FTSE 350, and US Fortune 500 board of director members regarding the significance of gender and racial diversity on board governance. Perceptions were gathered from eighty-two directors using self-reported surveys and semi-structured interviews. This thesis provides: (1) an opportunity to investigate the perceptions (opinions) of directors regarding the effects of board gender and racial diversity on new board appointments and on the dynamics of board decision making (2) an opportunity to investigate the perception (opinions) of directors regarding the effects of social capital, new board appointments and the dynamics of board decision making, and (3) an opportunity to investigate comparatively the differences between UK and US director perceptions regarding the effects of board gender and racial diversity on new board appointments and board decision making. My findings indicate that directors believe that expertise and experience are by far the most important attributes when decisions on the selection of new directors are being considered. While US directors report observing tangible benefits to gender and racial diversity, for their firms, as well as a willingness to consider diversity as an attribute in the selection process; most UK directors were strongly opposed to positive discrimination measures.1 A majority of directors do not believe that their own demographic characteristics, such as race or gender were attributes to their being selected to a board position; however white males perceive that these attributes were considered attributes to the appointment of diverse directors. Moreover, in the United Kingdom, male directors reported that they may be at a disadvantage for board selection when compared to their female counterparts, hence advocating for a selection process with minimal considerations of the demographic characteristics of new directors. Directors do not seem to consider diverse social capital of directors when making board appointments. Instead, US directors were more likely to be assisted in board appointments by their having similar social capital, and UK directors indicated that they only consider director expertise, and that expertise is considered to ensure a broad mix of skills and professional experience on the board.
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MCM-41's limited hydrothermal stability has been often related to the hydrolysis of Si-O-Si bonds due to the low degree of condensation, its thin walls or a combination of them. In this work, evidence for an additional factor is provided; a physical effect that occurs during the drying of the hydrothermally treated calcined material due to the intense capillary stress exerted in water. Depending on both physical (i.e. mechanical) and chemical (i.e. hydrolysis) resistances, the structure undergoes differently. Three MCM-41 samples with different degree of condensation were investigated. The most remarkable results are found with un-aged TEOS based material, which gets fully disordered and shrunk for all applied hydrothermal temperatures in water. Comparison between water and a low-surface-tension-solvent drying revealed that capillarity is responsible for the loss of ordering (and shrinkage) at moderate hydrothermal temperatures. The material's structure is hexagonal and shrinkage-free under the low-surface-tension-solvent route. At a high hydrothermal temperature, hydrolysis is extensive and responsible for the loss of ordering. The other remarkable finding regards the aged MCM-41 mesostructure that maintains the hexagonal features at all applied temperatures in water, and it is more stable against capillarity at high temperature. The Na-metasilicate based material is mechanically very stable and gets disordered at high temperature due to hydrolysis.
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The aim of this paper is to shed the light on the relationship between New Public Management and Hungary’s Zoltán Magyary Public Administration Development Programme. As will be shown, the Magyary Programme has a dual structure. The systemic reforms run counter to the NPM philosophy because the main goal is the centralization of public administration, while NPM clearly advocates decentralization. At the same time, reform proposals on the organizational level conform to NPM. The inconsistencies in the Magyary Programme itself and the probable political and organizational resistance towards its proposals could delay the introduction of reforms on the organizational level.
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The aim of the paper is to highlight the main characteristics of the recent Hungarian public administration reform, as well as to reveal the inconsistent nature of some of its elements and to describe the connected risks. The starting point of the article is the Magyary Zoltán public administration development programme. The reform steps are compared to the ideal type NPM approach. The Hungarian public administration reform can be characterized by strong centralization and the revitalization of Hungarian anti-liberal traditions at macro level, and by the support of the enhancement of market rules and management at micro level.
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The present study examines the extent to which blacks are segregated in the suburban community of Coconut Grove, Florida. Hypersegregation, or the general tendency for blacks and whites to live apart, was examined in terms of four distinct dimensions: evenness, exposure, clustering, and concentration. Together, these dimensions define the geographic traits of the target area. Alone these indices can not capture the multi-dimensional levels of segregation and, therefore, by themselves underestimate the severity of segregation and isolation in this community. This study takes a contemporary view of segregation in a Dade County community to see if segregation is the catalyst to the sometime cited violent response of blacks. This study yields results that support the information in the literature review and the thesis research questions sections namely, that the blacks within the Grove do respond violently to the negative effects that racial segregation causes. This thesis is unique in two ways. It examines segregation in a suburban environment rather than an urban inner city, and it presents a responsive analysis of the individuals studied, rather than relying only on demographic and statistical data. ^
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Immigrants from the West Indies and other nations challenge the simple United States dichotomy of blacks versus whites. Many apparently black Caribbean immigrants proclaim that they did not know they were “black” until they arrived in the U.S. They seek to maintain their national identity and resist identity and solidarity with Black Americans. In response, many Black Americans respond that the immigrants are simply being naive, that U.S. society demands simple racial identity. Regardless of one's self-identity and personal history, in the U.S., if you look black, you are black, was their thinking. ^ This study examines the contemporary struggle of identity and solidarity among and between Black Americans and Jamaicans living in South Florida (Broward and Miami-Dade counties). Even though the primary focus of this study is to examine the relationship between Black Americans and Jamaicans, other West Indian nationals will be addressed more generally. The primary research problem of this study is to determine why the existence of common ancestry and physical traits are insufficient for an assumption of ethnic solidarity between Black Americans and Jamaicans. ^ In examining this problem, I felt that depth rather than breadth would provide insight into the current state of polarization between Black Americans and Jamaicans. To this end, a qualitative study was designed. A non-random snowball sample consisting of forty-seven informants was selected for this study. Realizing that such a technique presents problems with generalizations beyond the sample, this approach was, nonetheless, the most suitable for the current research problem. One of the initial challenges of this research was the use of the label “black” in discussing Caribbean immigrants. Unlike America, where distinctions based on skin color were at the bedrock of America's formation, this was not the case in the Caribbean. In the Caribbean skin color was an important marker as an indicator of class, rather than of race. Therefore, I refrained from using the label, “black Jamaicans,” but rather used Jamaicans throughout. ^
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Since the arrival of the first African slaves to Cuba in 1524, the issue of race has had a long-lived presence in the Cuban national discourse. However, despite Cuba’s colonial history, it has often been maintained by some historians that race relations in Cuba were congenial with racism and racial discrimination never existing as deep or widespread in Cuba as in the United States (Cannon, 1983, p. 113). In fact, it has been argued that institutionalized racism was introduced into Cuban society with the first U.S. occupation, during 1898–1902 (Cannon, 1983, p. 113). This study of Cuba investigates the influence of the United States on the development of race relations and racial perceptions in post-independent Cuba, specifically from 1898-1902. These years comprise the time period immediately following the final fight for Cuban Independence, culminating with the Cuban-Spanish-American War and the first U.S. occupation of Cuba. By this time, the Cuban population comprised Africans as well as descendants of Africans, White Spanish people, indigenous Cubans, and offspring of the intermixing of the groups. This research studies whether the United States’ own race relations and racial perceptions influenced the initial conflicting race relations and racial perceptions in early and post-U.S. occupation Cuba. This study uses a collective interpretative framework that incorporates a national level of analysis with a race relations and racial perceptions focus. This framework reaches beyond the traditionally utilized perspectives when interpreting the impact of the United States during and following its intervention in Cuba. Attention is given to the role of the existing social, political climate within the United States as a driving influence of the United States’ involvement with Cuba. This study reveals that emphasis on the role of the United States as critical to the development of Cuba’s race relations and racial perceptions is credible given the extensive involvement of the U.S. in the building of the early Cuban Republic and U.S. structures serving as models for reconstruction. U.S. government formation in Cuba aligned with a governing system reflecting the existing governing codes of the U.S. during that time period.