4,355 research outputs found

    Einstein Geometrization Philosophy and Differential Identities in PAP-Geometry

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    The importance of Einstein's geometrization philosophy, as an alternative to the least action principle, in constructing general relativity (GR), is illuminated. The role of differential identities in this philosophy is clarified. The use of Bianchi identity to write the field equations of GR is shown. Another similar identity in the absolute parallelism geometry is given. A more general differential identity in the parameterized absolute parallelism geometry is derived. Comparison and interrelationships between the above mentioned identities and their role in constructing field theories are discussed.Comment: LaTeX file, 17 pages, comments and criticism are welcom

    Simulating Research Behaviour

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    XPS characterization of Bi and Mn collected on atom-trapping silica for AAS

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    The chemical state of analyte species collected on a water-cooled silica tube during atom-trapping atomic absorption spectrometric determination is investigated with the use of X-ray photoelectron spectroscopy (XPS) for Bi and Mn. Analysis of the Bi 4f(7/2) peak reveals that the chemical state of Bi is +3 during initial trapping (before the atomization stage), but an additional 0-valence state of Bi is also observed after the atomization stage. With the use of the measured Mn 2p(3/2) binding energy together with the observed 3s multiplet splitting, the chemical state of Mn is determined as +2 in all stages. Together with our previous determination of 0 valence for Au, it is now postulated that the stability of certain valence states of the three elements (Au, Bi, and Mn) on the silica matrix can be correlated to their electrochemical reduction potentials

    Assessing a Practical Classroom of Takoradi Technical University – An End-User Perspective

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    This study evaluated the newly refurbished building used as a kitchen for practical lessons at the Hospitality Management Department of Takoradi Technical University, Ghana. It aimed at identifying the challenges faced by users and assessing their satisfsction with the facility. A questionnaire survey approach and covert observations were adopted to gather data. Questionnaires were self-administered to 150 randomly sampled Higher National Diploma students of the department. Data were analysed and presented in tables as frequencies, percentages and mean scores. The study identified lack of changing rooms, lack of storage facilities, congestion and inadequate natural ventilation as some of the challenges faced by users of the kitchen. The overall mean satisfaction score was 2.46 which is an indication that users are dissatisfied with the facility. This study would help inform design decisions to improve upon the performance of future students’ practical rooms to be constructed in the institution. Key words: Challenges, Kitchen, Practical’s, Post Occupancy Evaluation, User Satisfaction

    COVID-19 infection and death rates: the need to incorporate causal explanations for the data and avoid bias in testing

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    COVID-19 testing strategies are primarily driven by medical need - focusing on people already hospitalized with significant symptoms or on people most at risk. However, such testing is highly biased because it fails to identify the extent to which COVID-19 is present in people with mild or no symptoms. If we wish to understand the true rate of COVID-19 infection and death, we need to take full account of the causal explanations for the resulting data to avoid highly misleading conclusions about infection and death rates. We describe how causal (Bayesian network) models can provide such explanations and the need to combine these with more random testing in order to achieve reliable data and predictions for the both policy makers and the public

    An arthroscopic evaluation of the anatomical “critical zone”

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    Background: The “critical zone”, a region of speculated vascularity, is situated approximately 10 mm proximal to the insertion of the supraspinatus tendon. Despite its obvious role as an anatomical landmark demarcator, its patho-anatomic nature has been identified as the source of rotator cuff pathology. Although many studies have attempted to evaluate the vascularity of this region, the architecture regarding the exact length, width and shape of the critical zone, remains unreported. This study aimed to determine the shape and morphometry of the “critical zone” arthroscopically. Materials and methods: The sample series, which was comprised of 38 cases (n = 38) specific to pathological types, employed an anatomical investigation of the critical zone during routine real-time arthroscopy. Demographic representation: i) sex: 19 males, 19 females; ii) age range: 18–76 years; iii) race: white (n = 29), Indian (n = 7) and coloured (n = 2). Results: The incidence of shape and the mean lengths and widths of the critical zone were determined in accordance with the relevant demographic factors and patient history. Although the cresenteric shape was predominant, hemispheric and sail-shaped critical zones were also identified. The lengths and widths of the critical zone appeared markedly increased in male individuals. While the increase in age may account for the increased incidence of rotator cuff degeneration due to poor end-vascular supply, the additional factors of height and weight presented as major determinants of the increase in size of the critical zone. Conclusions: In addition, the comparisons of length and width with each other and shape yielded levels of significant difference, therefore indicating a directly proportional relationship between the length and width of the critical zone. This detailed understanding of the critical zone may prove beneficial for the success of post-operative rotator cuff healing

    Calcific aortic valve disease and hypertension

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    This review addresses the role of hypertension in precipitating Calcific aortic valve disease (CAVD) and the therapeutic potential of anti-hypertensive interventions to ameliorate CAVD. CAVD was originally considered to be a degenerative disease representing the "wear and tear" of the aortic valves. More recently both conceptually and experimentally, CAVD has come to be considered the result of an active disease process, Whilst, there are some common factors in the pathology and risk factors for atherosclerosis and CAVD there are also some distinct differences. Hypertension is an established risk factor for coronary artery disease and has been recognised as a risk factor for CAVD. Angiotensin converting enzyme inhibitors have been found to have beneficial effects in CAVD and as in atherosclerosis such effects may be due to the blood pressure lowering action but also to direct pleiotropic effects on the biochemical and cellular mechanisms of disease progression in the respective tissues. The very high prevalence of hypertension in the community coupled with an aging population, a risk factor associated with both hypertension and CAVD, infers that hypertension will be one of the predominant factors that increase the impact of CAVD on human health in the coming decades

    Transforming growth factor-b regulation of proteoglycan synthesis in vascular smooth muscle: Contribution to lipid binding and accelerated atherosclerosis in diabetes

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    Atherosclerosis is accelerated in the setting of diabetes, but the factors driving this phenomenon remain elusive. Hyperglycemia leads to elevated levels of transforming growth factor (TGF)-b and TGF-b has been implicated as a factor in atherosclerosis. Given the established association between hyperglycemia and elevated TGF-b, it is plausible that elevated TGF-b levels in diabetes play a pathogenic role in the development of accelerated atherosclerosis. TGF-b is a potent regulator of extracellular matrix synthesis, including many actions on proteoglycan synthesis that lead to increased binding to low-density lipoprotein and therefore potentially increased lipid retention in the vessel wall and accelerated atherosclerosis. TGF-b signals through the canonical TGF-b receptor I-mediated phosphorylation of Smad transcription factors and TGF-b signaling is also known to involve, positively and negatively, interactions with the mitogen-activated protein kinase pathways. The focus of the present review is on the effects of TGF-b on proteoglycan synthesis in vascular smooth muscle and particularly the signaling pathways through which TGF-b exerts its effects, because those pathways may be therapeutic targets for the prevention of pathological modifications in the proteoglycan component of the vessel wall in the vascular diseases of diabetes

    Evaluation of BIM Education for Quantity Surveying: A Review of Teaching Approaches

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    Building Information Modelling (BIM) technology has become increasingly well-known among construction industry players throughout the world. It is known as a process that offers numerous benefits by the implementation in the industry. Almost 50% of practitioners in construction industry is using BIM. Quantity Surveyors (QS) are one of the important main professionals in construction industry who should have an adequate and sufficient BIM knowledge and skills. Equivalent to this, based on the educational perspective it is clear that there is a growing need for universities to provide their graduates with appropriate BIM-related skills. Although the educational frameworks that have been established for academic purposes in Malaysia, still, it is in doubt whether this framework is parallel with industry’s demand and also whether the knowledge and skills provided sufficient with industry’s requirements. It is crucial to recognize the applicable teaching approach for BIM educations in order to ensure students capable in applying BIM tools and meet the expectation of industry. This paper reviews the BIM teaching approaches and the BIM module applied in QS undergraduate program.   Keywords: BIM, quantity surveyors, QS education, teaching approach, Malaysi

    Expected Future Precipitation in Central Iraq Using LARS-WG Stochastic Weather Generator

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    The Middle East (ME) is characterized by its water shortage problem. This region with its arid climate is expected to be the most vulnerable in the world to the potential impacts of climate change. Iraq (located in ME) is seriously experiencing water shortage problem. To overcome this problem rain water harvesting can be used. In this study the applicability of the long-term weather generator model in downscaling daily precipitation Central Iraq is used to project future changes of precipitation based on scenario of seven General Circulation Models (GCMs) outputs for the periods of 2011-2030, 2046-2065, and 2080-2099. The results indicated that December-February and September-November periods, based on the ensemble mean of seven GCMs, showed an increasing trend in the periods considered; however, a decreasing trend can be found in March, April, and May in the future
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