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Conventional Measures (conventional + measure)
Selected AbstractsDo Peer Groups Matter?ECONOMICA, Issue 277 2003Peer Group versus Schooling Effects on Academic Attainment This paper estimates an educational production function. Educational attainment is a function of peer group, parental input and schooling. Conventional measures of school quality are not good predictors for academic attainment, once we control for peer group effects; parental qualities also have strong effects on academic attainment. This academic attainment is a then a key determinant of subsequent labour market success, as measured by earnings. The main methodological innovation in this paper is the nomination of a set of instruments, very broad regions of birth, which, as a whole, pass close scrutiny for validity and permit unbiased estimation of the production function. [source] Changes in oxyhemoglobin dissociation curve in intrabdominal organs during pig experimental orthotopic liver transplantationLIVER TRANSPLANTATION, Issue 7 2005Georgia Kostopanagiotou Liver transplantation has become a gold standard treatment for irreversible liver disease. Conventional measures of oxygenation are inadequate to understand the dynamics of regional oxygen metabolism during liver transplantation because they represent global markers of tissue dysoxia. Therefore, the addition of an assessment of the hemoglobin O2 binding capacity can give a better insight into systemic and regional tissue oxygenation and can reflect a more accurate estimation of oxygen release to the tissues than can the hemoglobin, the PaO2 and SaO2 alone. This prospective study was designed to evaluate possible alterations in the oxyhemoglobin dissociation curve of vital end organs (small bowel, liver, and kidney) in an experimental liver transplantation model. Fifteen pigs with body weights ranging from 25 to 30 kg were used for the study. Five healthy pigs underwent a sham operation under general anesthesia (group A-control). Ten pigs underwent orthotopic liver transplantation (OLT). Five of them were healthy (group B), whereas the other five were in acute liver failure, which had been surgically induced (group C). Systemic arterial blood pressure, cardiac index, and pulmonary and systemic vascular resistance indexes were measured. Venous blood gas analysis was also performed from pulmonary artery, superior mesenteric, hepatic, and renal veins at well-defined timepoints during the course of the OLT. A statistically significant (P < 0.05) decrease of P50 in groups B and C compared with group A was observed 30 minutes after reperfusion in the systemic circulation, hepatic, and renal veins. This coincided with a decrease in animal temperature 30 minutes after reperfusion. Regarding group C, after reperfusion of the newly transplanted liver there was a significant increase of P50 in the small bowel in comparison to baseline values. In conclusion, these changes in P50 may suggest the occurrence of abnormal tissue oxygenation after reperfusion. (Liver Transpl 2005;11:760,766.) [source] Using Image and Curve Registration for Measuring the Goodness of Fit of Spatial and Temporal PredictionsBIOMETRICS, Issue 4 2004Cavan Reilly Summary Conventional measures of model fit for indexed data (e.g., time series or spatial data) summarize errors in y, for instance by integrating (or summing) the squared difference between predicted and measured values over a range of x. We propose an approach which recognizes that errors can occur in the x -direction as well. Instead of just measuring the difference between the predictions and observations at each site (or time), we first "deform" the predictions, stretching or compressing along the x -direction or directions, so as to improve the agreement between the observations and the deformed predictions. Error is then summarized by (a) the amount of deformation in x, and (b) the remaining difference in y between the data and the deformed predictions (i.e., the residual error in y after the deformation). A parameter, ,, controls the tradeoff between (a) and (b), so that as ,,, no deformation is allowed, whereas for ,= 0 the deformation minimizes the errors in y. In some applications, the deformation itself is of interest because it characterizes the (temporal or spatial) structure of the errors. The optimal deformation can be computed by solving a system of nonlinear partial differential equations, or, for a unidimensional index, by using a dynamic programming algorithm. We illustrate the procedure with examples from nonlinear time series and fluid dynamics. [source] Alcohol consumption and liver cirrhosis mortality with and without mention of alcohol,the case of CanadaADDICTION, Issue 9 2003Mats Ramstedt ABSTRACT Aims, To analyse post-war variations in per capita alcohol consumption in relation to gender-specific liver cirrhosis mortality in Canadian provinces and to assess the extent to which alcohol bears a different relation to cirrhosis deaths with mention of alcohol (alcoholic cirrhosis) compared to cirrhosis deaths without mention of alcohol (non-alcoholic cirrhosis). Data and method, Annual liver cirrhosis mortality rates by 5-year age groups were converted into gender-specific and age-adjusted mortality rates. Outcome measures included total cirrhosis,the conventional measure of liver cirrhosis,alcoholic cirrhosis and non-alcoholic cirrhosis. Per capita alcohol consumption was measured by alcohol sales and weighted with a 10-year distributed lag model. A graphical analysis was used to examine the regional relationship and the Box,Jenkins technique for time-series analysis was used to estimate the temporal relationship. Findings, Geographical variations in alcohol consumption corresponded to variations in total liver cirrhosis and particularly alcoholic cirrhosis, whereas non-alcoholic cirrhosis rates were not associated geographically with alcohol consumption. In general, for all provinces, time-series analyses revealed positive and statistically significant effects of changes in alcohol consumption on cirrhosis mortality. In Canada at large, a 1-litre increase in per capita consumption was associated with a 17% increase in male total cirrhosis rates and a 13% increase in female total cirrhosis rates. Alcohol consumption had a stronger impact on alcoholic cirrhosis, which increased by fully 30% per litre increase in alcohol per capita for men and women. Although the effect on the non-alcoholic cirrhosis rate was weaker (12% for men and 7% for women) it was nevertheless statistically significant and suggests that a large proportion of these deaths may actually be alcohol-related. Conclusions, Some well-established findings in alcohol research were confirmed by the Canadian experience: per capita alcohol consumption is related closely to death rates from liver cirrhosis and alcohol-related deaths tend to be under-reported in mortality statistics. [source] Therapeutic targets in the management of Type 1 diabetesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue S1 2002P. D. Home Abstract For historical reasons, diabetes has long been linked with blood and urine glucose control, partly because these were clearly linked to acute symptoms, and partly because glucose became measurable around 200 years ago. Today it is recognized that there is far more to diabetes than simply monitoring symptoms and blood glucose. Intensive management has an impact on the quality of life. Late complications have their own risk factors and markers. Monitoring and early detection of these risk factors and markers can lead to changes in treatment before tissue damage is too severe. Accordingly, professionals now find themselves monitoring a range of adverse outcomes, markers for adverse outcomes, risk factors and risk markers for microvascular and arterial disease, acute complications of therapy, and the care structures needed to deliver this. Adverse outcomes lend themselves to targets for complication control in populations, and markers of adverse outcomes (such as retinopathy and raised albumin excretion rate) in treatment cohorts. Surveillance systems will have targets for yearly recall and review of early complications. Metabolic (surrogate) outcomes can be monitored in individual patients, but monitoring is only of value in so far as it guides interventions, and this requires comparison to some intervention level or absolute target. Even for blood glucose control this is not easy, for conventional measures such as glycated haemoglobin have their own problems, and more modern approaches such as post-prandial glucose levels are controversial and less convenient to measure. In many people with type 1 diabetes targets for blood pressure, LDL cholesterol, and serum triglycerides will also be appropriate, and need to be part of any protocol of management. Copyright © 2002 John Wiley & Sons, Ltd. [source] Decline in the quality of suspended fine particulate matter as a food resource for chironomids downstream of an urban areaFRESHWATER BIOLOGY, Issue 5 2004Emma J. Rosi-MarshallArticle first published online: 16 APR 200 Summary 1. Urbanization and its associated contamination could degrade the quality of suspended fine particulate organic matter (SFPM) (20 ,m to 1 mm) as a food resource for aquatic insects. SFPM was collected at four sites along the main stem of the Chattahoochee River, which drains metropolitan Atlanta at base and high flow during four seasons. 2. Composition of SFPM was estimated using measures conventionally associated with food quality: bacteria, N/C ratio, caloric content, % inorganic, and % lipids, and metal (Cd, Cu, Pb, and Zn) concentration. In SFPM collected during base flow, % inorganic matter, calories, Cu, Pb, and Zn concentrations increased with cumulative permitted wastewater treatment discharge (an indicator of extent of urbanization upstream). In SFPM samples collected during high flow, % diatoms, Cu, Pb and Zn concentrations increased with urbanization. 3. A growth assay was used as an integrated and direct measure of SFPM quality as a food resource. The instantaneous growth rate (IGR) of chironomids fed SFPM collected during base flow declined downstream of the city. IGRs of chironomids fed SFPM collected at all sites during high flow were as low as the lowest IGR measured during base flow. 4. Insects fed SFPM collected from the Chattahoochee River had IGRs only 20% of those of chironomids fed SFPM collected from the Little Tennessee River, a relatively undisturbed river in North Carolina. The mortality rate of chironomids fed SFPM was not different among sites or rivers. While the decline in SFPM quality in the Chattahoochee River is probably attributable to some aspect of urbanization, the decline was not related to conventional measures of food quality or metal contamination. [source] Measurement of Brain and Spinal Cord Atrophy by Magnetic Resonance Imaging as a Tool to Monitor Multiple SclerosisJOURNAL OF NEUROIMAGING, Issue 2005FAAN, Rohit Bakshi MD ABSTRACT Evaluation of brain and spinal cord atrophy by magnetic resonance imaging (MRI) has become an increasingly important component of understanding the multiple sclerosis (MS) disease process. These destructive aspects of the disease develop early in the disease course. A growing body of data links brain and spinal cord atrophy to clinical impairment more closely than can be linked with conventional measures of overt lesions. Thus, irreversible tissue damage may be a key factor leading to disease progression. In this review, the authors present the proposed mechanisms leading to central nervous system (CNS) atrophy. They describe the available MRI-based techniques to measure regional and global atrophy of the brain and spinal cord. They compare the rate of atrophy among MS phenotypes and summarize the emerging data linking atrophy to neurological and neuropsychological impairment. Finally, they discuss the effect of disease-modifying immunotherapies on the rate of CNS atrophy in patients with MS. Future research to clarify the etiology and pathophysiology of brain and spinal cord atrophy should provide new targets for therapeutic development. [source] Activity of Bacillus thuringiensis toxins against cocoa pod borer larvaePEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2004Djoko Santoso Abstract Twelve Cry proteins from Bacillus thuringiensis Berliner were tested in bioassays on cacao plantations in Indonesia for activity against the larvae of cocoa pod borer (Conopomorpha cramerella (Snellen)), an insect pest of the cacao tree. Through the damage caused by their feeding, the larvae of cocoa pod borer cause the pods of the cocoa tree to ripen prematurely. They are difficult to control with conventional measures. Preliminary assays identified five toxins that were more active than others. In two subsequent bioassays the activity of selected toxins was determined more accurately. Three Cry1 proteins with relatively little homology were all found to be toxic, opening perspectives for controlling cocoa pod borer by expression of Cry proteins in transgenic plants. Copyright © 2004 Society of Chemical Industry [source] Business First: Work Relations in Cape Breton's "Progressive" Third SectorANTHROPOLOGY OF WORK REVIEW, Issue 1 2005Constance P. DeRoche Abstract Cape Breton Island, the northeastern portion of Canada's province of Nova Scotia, has a long history of both economic malaise and experimentation with innovative forms of economic organization. Disillusioned with both private enterprise and state economic intervention, local activists have, over the last three decades, worked to develop community-oriented, "third-sector" ventures. Building on the grassroots tradition of the region's "Antigonish Movement," and inspired by the Basque worker co-operatives of Mondragón, these reformers have established enterprises that purport to be progressive. This article examines that reformist claim as it pertains to a group of not-for-profit companies called New Dawn Enterprises, as well as the community-investment firm it spawned, BCA. The analysis suggests that while these firms, in some ways, have "socialized" capital, they have done nothing to restructure labor-management relations. Experimentation with workplace democracy has been sacrificed for conventional measures of business success. That is, though it is not privately appropriated in these firms, financial profit is the top priority. [source] On some measures and distances for positive random variablesAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 2 2003M. S. FinkelsteinArticle first published online: 2 MAY 200 Abstract A number of conventional measures of risk as real-valued functions on the space of positive random variables are considered: the expected shortfall, the mean excess over the threshold, the stop-loss and some others. Ordering of risks, based on these measures and the distances between corresponding distribution functions, are described. The perturbed measures, describing the effect of changing environment, are discussed. These measures are defined by the accelerated life and proportional hazards models widely used in reliability and survival analysis. The case of a random environment is of a prime interest in the paper. The main result states that if, for instance, the stochastic environment is ,neutral in expectation' with respect to the baseline one, the distance between the corresponding distribution functions can be still sufficiently large. Copyright © 2003 John Wiley & Sons, Ltd. [source] | |||||||||||||