328 research outputs found

    Casimir Energy of the Universe and New Regularization of Higher Dimensional Quantum Field Theories

    Full text link
    Casimir energy is calculated for the 5D electromagnetism and 5D scalar theory in the {\it warped} geometry. It is compared with the flat case. A new regularization, called {\it sphere lattice regularization}, is taken. In the integration over the 5D space, we introduce two boundary curves (IR-surface and UV-surface) based on the {\it minimal area principle}. It is a {\it direct} realization of the geometrical approach to the {\it renormalization group}. The regularized configuration is {\it closed-string like}. We do {\it not} take the KK-expansion approach. Instead, the position/momentum propagator is exploited, combined with the {\it heat-kernel method}. All expressions are closed-form (not KK-expanded form). The {\it generalized} P/M propagators are introduced. We numerically evaluate \La(4D UV-cutoff), \om(5D bulk curvature, warp parameter) and TT(extra space IR parameter) dependence of the Casimir energy. We present two {\it new ideas} in order to define the 5D QFT: 1) the summation (integral) region over the 5D space is {\it restricted} by two minimal surfaces (IR-surface, UV-surface) ; or 2) we introduce a {\it weight function} and require the dominant contribution, in the summation, is given by the {\it minimal surface}. Based on these, 5D Casimir energy is {\it finitely} obtained after the {\it proper renormalization procedure.} The {\it warp parameter} \om suffers from the {\it renormalization effect}. The IR parameter TT does not. We examine the meaning of the weight function and finally reach a {\it new definition} of the Casimir energy where {\it the 4D momenta(or coordinates) are quantized} with the extra coordinate as the Euclidean time (inverse temperature). We examine the cosmological constant problem and present an answer at the end. Dirac's large number naturally appears.Comment: 13 paes, 8 figures, proceedings of 1st Mediterranean Conf. on CQ

    Clinical Predictors and Outcome of Metabolic Acidosis in Under-Five Children Admitted to an Urban Hospital in Bangladesh with Diarrhea and Pneumonia

    Get PDF
    BACKGROUND: Clinical features of metabolic acidosis and pneumonia frequently overlap in young diarrheal children, resulting in differentiation from each other very difficult. However, there is no published data on the predictors of metabolic acidosis in diarrheal children also having pneumonia. Our objective was to evaluate clinical predictors of metabolic acidosis in under-five diarrheal children with radiological pneumonia, and their outcome. METHODS: We prospectively enrolled all under-five children (n = 164) admitted to the Special Care Ward (SCW) of the Dhaka Hospital of icddr, b between September and December 2007 with diarrhea and radiological pneumonia who also had their total serum carbon-dioxide estimated. We compared the clinical features and outcome of children with radiological pneumonia and diarrhea with (n = 98) and without metabolic acidosis (n = 66). RESULTS: Children with metabolic acidosis more often had higher case-fatality (16% vs. 5%, p = 0.039) compared to those without metabolic acidosis on admission. In logistic regression analysis, after adjusting for potential confounders such as age of the patient, fever on admission, and severe wasting, the independent predictors of metabolic acidosis in under-five diarrheal children having pneumonia were clinical dehydration (OR 3.57, 95% CI 1.62-7.89, p = 0.002), and low systolic blood pressure even after full rehydration (OR 1.02, 95% CI 1.01-1.04, p = 0.005). Proportions of children with cough, respiratory rate/minute, lower chest wall indrawing, nasal flaring, head nodding, grunting respiration, and cyanosis were comparable (p>0.05) among the groups. CONCLUSION AND SIGNIFICANCE: Under-five diarrheal children with radiological pneumonia having metabolic acidosis had frequent fatal outcome than those without acidosis. Clinical dehydration and persistent systolic hypotension even after adequate rehydration were independent clinical predictors of metabolic acidosis among the children. However, metabolic acidosis in young diarrheal children had no impact on the diagnostic clinical features of radiological pneumonia which underscores the importance of early initiation of appropriate antibiotics to combat morbidity and deaths in such population

    Collaborative design of accessible information with people with aphasia

    Get PDF
    Background: People with aphasia report preferences for specially formatted health information materials, but there is little evidence that modified materials result in improved comprehension. Potential explanations for this include language included not taking account of aphasic processing difficulties, topics unrelated to aphasia, lack of clarity regarding the use of images, and the lack of end-user involvement in the design. Additionally, no definitive criteria for production of accessible information have been identified. Aims: The first aim of this study was to collaborate with people with aphasia in an iterative design process to develop and finalise accessible information materials. The second aim was to identify definitive criteria for use in the future production of information materials for people with aphasia. Methods and procedure: Prototype materials were developed for the study, were based on criteria identified from the existing research into aphasia-accessible information, and on the evidence base concerning language processing in aphasia. Fourteen people with aphasia took part in two rounds of consensus group meetings and viewed information about aphasia presented within the prototype materials. Consensus points were identified within the groups through discussion and through ratings using Likert scales. The set of consensus points and ratings were adapted into criteria for graphic designers to incorporate into subsequent designs of the materials, in order to generate a final version, and related criteria. Outcomes and results: The group discussions and the ratings of materials led to the identification of an agreed layout within which to present information, and specific criteria for the following: information consisting of one proposition expressed via everyday words and canonical syntactic forms; one or two images relating directly to keywords; sans serif typography with keyword emphasis. Individual preferences with regard to image types were identified. Novel criteria were identified in the study, relating to layout, language, images and typography. These were added to the original set of criteria to form definitive criteria for use in the development of accessible aphasia materials. Conclusions: This study successfully involved people with aphasia in the design process to produce novel materials, and related design criteria. The resulting materials and criteria differ from those previously proposed, by reflecting directly people with aphasia’s views and preferences, and by incorporating language and images suitable for people with aphasia, based on the existing research evidence and the outcomes of this study. The materials and criteria have the potential to improve people with aphasia’s understanding of health information

    Interactions of malnutrition and immune impairment, with specific reference to immunity against parasites

    Get PDF
    KEY POINTS: 1. Clinical malnutrition is a heterogenous group of disorders including macronutrient deficiencies leading to body cell mass depletion and micronutrient deficiencies, and these often coexist with infectious and inflammatory processes and environmental problems. 2. There is good evidence that specific micronutrients influence immunity, particularly zinc and vitamin A. Iron may have both beneficial and deleterious effects depending on circumstances. 3. There is surprisingly slender good evidence that immunity to parasites is dependent on macronutrient intake or body composition

    Deliver us from Evil: The Effects of Mortality Salience and Reminders of 9/11 on Support for President George W. Bush

    Get PDF
    According to terror management theory, heightened concerns about mortality should intensify the appeal of charismatic leaders. To assess this idea, we investigated how thoughts about death and the 9/11 terrorist attacks influence Americans’ attitudes toward current U.S. President George W. Bush. Study 1 found that reminding people of their own mortality (mortality salience) increased support for Bush and his counterterrorism policies. Study 2 demonstrated that subliminal exposure to 9/11-related stimuli brought death-related thoughts closer to consciousness. Study 3 showed that reminders of both mortality and 9/11 increased support for Bush. In Study 4, mortality salience led participants to become more favorable toward Bush and voting for him in the upcoming election but less favorable toward Presidential candidate John Kerry and voting for him. Discussion focused on the role of terror management processes in allegiance to charismatic leaders and political decision making.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
    corecore