882 resultados para The Availability Theory
Resumo:
OBJECTIVES: Fever is one of the most commonly seen symptoms in the pediatric emergency department. The objective of this study was to observe how the rapid testing for influenza virus impacts on the management of children with fever. METHODS: We performed a review of our pediatric emergency department records during the 2008/2009 annual influenza season. The BinaxNow Influenza A+B test was performed on patients with the following criteria: age 1.0 to 16.0 years, fever greater than 38.5 °C, fever of less than 96 hours' duration after the onset of clinical illness, clinical signs compatible with acute influenza, and nontoxic appearance. Additional laboratory tests were performed at the treating physician's discretion. RESULTS: The influenza rapid antigen test was performed in 192 children. One hundred nine (57%) were influenza positive, with the largest fraction (101 patients) positive for influenza A. The age distribution did not differ between children with negative and positive test results (mean, 5.3 vs. 5.1 years, not statistically significant). A larger number of diagnostic tests were performed in the group of influenza-negative patients. Twice as many complete blood counts, C-reactive protein determinations, lumbar punctures, and urinalyses were ordered in the latter group. CONCLUSIONS: Rapid diagnosis of influenza in the pediatric emergency department affects the management of febrile children as the confirmation of influenza virus infection decreases additional diagnostic tests ordered.
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Cystic adventitial disease is a rare non-atheromatous cause of popliteal artery disease. We report a case of a 54-year-old patient with claudication of the right calf caused by cystic adventitial disease. Intra-operatively, a communication between the adventitia and the knee joint was identified. Connections between the adventitial cyst and the nearby joint have been reported in the literature that support the developmental theory. This theory suggests that cystic adventitial disease is a developmental manifestation of mucin-secreting cells derived from the mesenchyme of the adjacent joint. This case is the first, to our knowledge, in which a communication between joint and adventitia has been clearly documented by operative findings.
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The theory on the intensities of 4f-4f transitions introduced by B.R. Judd and G.S. Ofelt in 1962 has become a center piece in rare-earth optical spectroscopy over the past five decades. Many fundamental studies have since explored the physical origins of the Judd–Ofelt theory and have proposed numerous extensions to the original model. A great number of studies have applied the Judd–Ofelt theory to a wide range of rare-earth doped materials, many of them with important applications in solid-state lasers, optical amplifiers, phosphors for displays and solid state lighting, upconversion and quantum-cutting materials, and fluorescent markers. This paper takes the view of the experimentalist who is interested in appreciating the basic concepts, implications, assumptions, and limitations of the Judd–Ofelt theory in order to properly apply it to practical problems. We first present the formalism for calculating the wavefunctions of 4f electronic states in a concise form and then show their application to the calculation and fitting of 4f-4f transition intensities. The potential, limitations and pitfalls of the theory are discussed, and a detailed case study of LaCl3:Er3+ is presented.
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OBJECTIVE Obtaining new details of radial motion of left ventricular (LV) segments using velocity-encoding cardiac MRI. METHODS Cardiac MR examinations were performed on 14 healthy volunteers aged between 19 and 26 years. Cine images for navigator-gated phase contrast velocity mapping were acquired using a black blood segmented κ-space spoiled gradient echo sequence with a temporal resolution of 13.8 ms. Peak systolic and diastolic radial velocities as well as radial velocity curves were obtained for 16 ventricular segments. RESULTS Significant differences among peak radial velocities of basal and mid-ventricular segments have been recorded. Particular patterns of segmental radial velocity curves were also noted. An additional wave of outward radial movement during the phase of rapid ventricular filling, corresponding to the expected timing of the third heart sound, appeared of particular interest. CONCLUSION The technique has allowed visualization of new details of LV radial wall motion. In particular, higher peak systolic radial velocities of anterior and inferior segments are suggestive of a relatively higher dynamics of anteroposterior vs lateral radial motion in systole. Specific patterns of radial motion of other LV segments may provide additional insights into LV mechanics. ADVANCES IN KNOWLEDGE The outward radial movement of LV segments impacted by the blood flow during rapid ventricular filling provides a potential substrate for the third heart sound. A biphasic radial expansion of the basal anteroseptal segment in early diastole is likely to be related to the simultaneous longitudinal LV displacement by the stretched great vessels following repolarization and their close apposition to this segment.
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We show that global properties of gauge groups can be understood as geometric properties in M-theory. Different wrappings of a system of N M5-branes on a torus reduce to four-dimensional theories with AN−1 gauge algebra and different unitary groups. The classical properties of the wrappings determine the global properties of the gauge theories without the need to impose any quantum conditions. We count the inequivalent wrappings as they fall into orbits of the modular group of the torus, which correspond to the S-duality orbits of the gauge theories.
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The entrepreneurial theory of the firm argues that entrepreneurship, properly understood, is a crucial but neglected element in explaining the nature and boundaries of the firm. By contrast, the theory of the entrepreneurial firm presumably seeks not to understand the nature and boundaries of "the firm" in general but rather to understand a particular type of firm: one that is entrepreneurial. This paper is an attempt to reconcile the two. After briefly delving for the concept of entrepreneurship in the work of Schumpeter, Kirzner, and (especially) Knight, the paper makes the case for the entrepreneurial theory of the firm. In such a theory, the firm exists as the solution to a coordination problem in a world of change and uncertainty, including Knightian or structural uncertainty. Taking a historical or developmental perspective, the paper then examines the changing nature of the entrepreneurial coordination problem over the life-cycle. In this formulation, "the entrepreneurial firm" is a nascent firm or proto-firm facing a problem of coordinating systemic change in economic capabilities. Lacking (by definition) adequate guidance from existing systems of rules of conduct embedded in markets or organizations, the entrepreneurial firm typically relies on a form of organization Max Weber called charismatic authority. In the end, although there is no such thing as a non-entrepreneurial firm, firms that must solve coordination problems in a world of novelty and systemic change ("entrepreneurial firms") are perhaps the purest case of the entrepreneurial theory of the firm.
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Purpose: School districts in the U.S. regularly offer foods that compete with the USDA reimbursable meal, known as `a la carte' foods. These foods must adhere to state nutritional regulations; however, the implementation of these regulations often differs across districts. The purpose of this study is to compare two methods of offering a la carte foods on student's lunch intake: 1) an extensive a la carte program in which schools have a separate area for a la carte food sales, that includes non-reimbursable entrees; and 2) a moderate a la carte program, which offers the sale of a la carte foods on the same serving line with reimbursable meals. ^ Methods: Direct observation was used to assess children's lunch consumption in six schools, across two districts in Central Texas (n=373 observations). Schools were matched on socioeconomic status. Data collectors were randomly assigned to students, and recorded foods obtained, foods consumed, source of food, gender, grade, and ethnicity. Observations were entered into a nutrient database program, FIAS Millennium Edition, to obtain nutritional information. Differences in energy and nutrient intake across lunch sources and districts were assessed using ANOVA and independent t-tests. A linear regression model was applied to control for potential confounders. ^ Results: Students at schools with extensive a la carte programs consumed significantly more calories, carbohydrates, total fat, saturated fat, calcium, and sodium compared to students in schools with moderate a la carte offerings (p<.05). Students in the extensive a la carte program consumed approximately 94 calories more than students in the moderate a la carte program. There was no significant difference in the energy consumption in students who consumed any amount of a la carte compared to students who consumed none. In both districts, students who consumed a la carte offerings were more likely to consume sugar-sweetened beverages, sweets, chips, and pizza compared to students who consumed no a la carte foods. ^ Conclusion: The amount, type and method of offering a la carte foods can significantly affect student dietary intake. This pilot study indicates that when a la carte foods are more available, students consume more calories. Findings underscore the need for further investigation on how availability of a la carte foods affects children's diets. Guidelines for school a la carte offerings should be maximized to encourage the consumption of healthful foods and appropriate energy intake.^
Resumo:
Spatial data are being increasingly used in a wide range of disciplines, a fact that is clearly reflected in the recent trend to add spatial dimensions to the conventional social sciences. Economics is by no means an exception. On one hand, spatial data are indispensable to many branches of economics such as economic geography, new economic geography, or spatial economics. On the other hand, macroeconomic data are becoming available at more and more micro levels, so that academics and analysts take it for granted that they are available not only for an entire country, but also for more detailed levels (e.g. state, province, and even city). The term ‘spatial economics data’ as used in this report refers to any economic data that has spatial information attached. This spatial information can be the coordinates of a location at best or a less precise place name as is used to describe administrative units. Obviously, the latter cannot be used without a map of corresponding administrative units. Maps are therefore indispensible to the analysis of spatial economic data without absolute coordinates. The aim of this report is to review the availability of spatial economic data that pertains specifically to Laos and academic studies conducted on such data up to the present. In regards to the availability of spatial economic data, efforts have been made to identify not only data that has been made available as geographic information systems (GIS) data, but also those with sufficient place labels attached. The rest of the report is organized as follows. Section 2 reviews the maps available for Laos, both in hard copy and editable electronic formats. Section 3 summarizes the spatial economic data available for Laos at the present time, and Section 4 reviews and categorizes the many economic studies utilizing these spatial data. Section 5 give examples of some of the spatial industrial data collected for this research. Section 6 provides a summary of the findings and gives some indication of the direction of the final report due for completion in fiscal 2010.