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Used Index (used + index)
Selected AbstractsA Surface-Based Approach to Measuring Spatial SegregationGEOGRAPHICAL ANALYSIS, Issue 2 2007David O'Sullivan Quantitative indices of residential segregation have been with us for half a century, but suffer significant limitations. While useful for comparison among regions, summary indices fail to reveal spatial aspects of segregation. Such measures generally consider only the population mix within zones, not between them. Zone boundaries are treated as impenetrable barriers to interaction between population subgroups, so that measurement of segregation is constrained by the zoning system, which bears no necessary relation to interaction among population subgroups. A segregation measurement approach less constrained by the chosen zoning system, which enables visualization of segregation levels at the local scale and accounts for the spatial dimension of segregation, is required. We propose a kernel density estimation approach to model spatial aspects of segregation. This provides an explicitly geographical framework for modeling and visualizing local spatial segregation. The density estimation approach lends itself to development of an index of spatial segregation with the advantage of functional compatibility with the most widely used index of segregation (the dissimilarity index D). We provide a short review of the literature on measuring segregation, briefly describe the kernel density estimation method, and illustrate how the method can be used for measuring segregation. Examples using a simulated landscape and two empirical cases in Washington, DC and Philadelphia, PA are presented. [source] Assessing the ecological integrity of a grassland ecosystem: the applicability and rapidity of the SAGraSS methodAFRICAN JOURNAL OF ECOLOGY, Issue 3 2009W. Kaiser Abstract The Grassland Biome is currently one of the most threatened biomes in South Africa and is in dire need of a biomonitoring protocol. The components of ecological integrity in these ecosystems are, however, too diverse and time-consuming to measure scrupulously. It is therefore necessary to develop a set of grassland indicators that are efficient and rapid in their assessment of grassland ecosystem integrity. The South African Grassland Scoring System (SAGraSS), based on the grassland insect community, is such a suggested indicator. The present study is the first to investigate the applicability and rapidity of this proposed method. Although SAGraSS scores correlated significantly with Ecological Index values (the most commonly used index by which veld condition is evaluated in central South Africa), the method proved to be tedious and the identification of insects taxing. We offer a number of changes to make the SAGraSS method a more rapid method of assessment. Résumé Le Biome « Prairies » est aujourd'hui un des plus menacés d'Afrique du Sud et a sérieusement besoin d'un protocole de biomonitoring. Les composantes de l'intégritéécologique de ces écosystèmes sont cependant trop diverses, et il faudrait trop de temps pour les mesurer scrupuleusement. Il est donc nécessaire de mettre au point un ensemble d'indicateurs pour les prairies qui soient efficaces et permettent d'évaluer rapidement l'intégrité de ces écosystèmes. Le système sud-africain South African Grassland Scoring System (SAGraSS), basé sur la communauté des insectes des prairies, est un des indicateurs qui fut proposé. Cette étude est la première qui analyse l'applicabilité et la rapidité de cette méthode. Bien que les résultats du SAGraSS soient significativement reliés aux valeurs de l'Indice Ecologique (EI , l'indice le plus utilisé pour évaluer les conditions écologiques du Veld au centre de l'Afrique du Sud), la méthode s'est avérée fastidieuse, et l'identification des insectes assez longue. Nous proposons un certain nombre de changements à apporter pour faire de la méthode SAGraSS une méthode d'évaluation plus rapide. [source] Using index of ventilation to assess response to treatment for acute pulmonary exacerbation in children with cystic fibrosis,PEDIATRIC PULMONOLOGY, Issue 8 2009FRACP, Paul D. Robinson MRCPCH Abstract Background The use of alternative more sensitive measures has become a focus of research in CF. The utility of indexes of ventilation, Lung Clearance Index (LCI) and peak aerobic capacity (peak VO2), were studied as assessment tools in gauging response to intravenous (IV) therapy in acute pulmonary exacerbation, in comparison to the more commonly used index of forced expiratory volume in 1,sec (FEV1). The utility of a previously published clinical score was further explored. Methods Patients aged 8,18 years admitted for IV antibiotic treatment of a pulmonary exacerbation were recruited. Spirometry, plethysmography, multiple breath nitrogen washout, exercise testing, and Cystic Fibrosis Clinical Score (CFCS) were performed on admission and prior to discharge. Results Twenty-eight patients were recruited, with a mean (range) age of 13.7 (8; 17) years, 16 female and 12 male. Mean (range) admission FEV1 was 61.4 (28; 92)% predicted, or z -score ,3.09 (,6.15; ,0.52), FVC 83.0 (38; 120)% predicted, or z -score ,1.71 (,5.66; ,1.17), and Shwachman,Kulczycki 68.9 (50; 90). FEV1 increased by 7.0% (P,<,0.01) from admission to discharge. Mean (range) admission LCI, 10.10 (6.87; 14.83), decreased by 3.8% (P,=,0.03). Mean (range) admission peak VO2 (ml/kg/min), 31.2 (23.4; 45.4), increased on discharge by 6.6% (P,<,0.01). Proposed clinical thresholds, based on the available variability data, highlighted the heterogeneity of response in lung function tests. Mean (range) admission CFCS, 26.5 (19; 39), decreased to 19.9 (13; 31) on discharge, a 25.2% improvement (P,<,0.01). CFCS demonstrated improvement in 27 of 28 patients. Changes in peak VO2 (r,=,,0.50, P,=,0.02) and LCI (r,=,0.48, P,=,0.01) correlated with CFCS change. Conclusions In children with mild-to-moderate CF, whilst statistically significant improvement in both LCI and peak VO2 were seen, heterogeneity of response was evident. The most consistent improvement was seen in CFCS. Correlation of LCI and peak VO2 with change in clinical score (CFCS) was seen. The full clinical significance of these changes in LCI and peak VO2 needs to be evaluated further with additional variability data. The CFCS may be useful in the assessment of response to treatment in CF but requires formal validation. Pediatr Pulmonol. 2009; 44:733,742. © 2009 Wiley-Liss, Inc. [source] Inference for Kappas for Longitudinal Study Data: Applications to Sexual Health ResearchBIOMETRICS, Issue 3 2008Yan Ma Summary Analysis of instrument reliability and rater agreement is used in a wide range of behavioral, medical, psychosocial, and health-care-related research to assess psychometric properties of instruments, consensus in disease diagnoses, fidelity of psychosocial intervention, and accuracy of proxy outcomes. For categorical outcomes, Cohen's kappa is the most widely used index of agreement and reliability. In many modern-day applications, data are often clustered, making inference difficult to perform using existing methods. In addition, as longitudinal study designs become increasingly popular, missing data have become a serious issue, and the lack of methods to systematically address this problem has hampered the progress of research in the aforementioned fields. In this article, we develop a novel approach based on a new class of kappa estimates to tackle the complexities involved in addressing missing data and other related issues arising from a general multirater and longitudinal data setting. The approach is illustrated with real data in sexual health research. [source] Why Are Chinese Exports Not So Special?CHINA AND WORLD ECONOMY, Issue 1 2009Shunli Yao C43; F10; F14 Abstract Applying a commonly used index for export sophistication in a cross-country study, Rodrik finds that the technological content of Chinese exports over the past decade has been so high that it cannot be explained simply by the economic fundamentals of a low-income country abundant with unskilled labor. Question has been raised for the empirical robustness of the index. I am also doubtful with Rodrik's analysis but develop my argument from a different perspective. This paper briefly reviews Rodrik's methodology and identifies other factors his empirical results potentially hinge on. Based on this, it elaborates on China's unique processing trade regime, the uneven distribution of its exports across Chinese regions and the limitation of HS codes in terms of identifying differentiated products, in an attempt to show that these factors also contribute to higher estimations of China's export sophistication level. Finally, it organizes trade data to reveal the trade patterns that are indeed consistent with the country's comparative advantage. [source] Classification of synchronous oceanic and atmospheric El Niño-Southern Oscillation (ENSO) events for palaeoclimate reconstructionINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2005Joëlle L. Gergis Abstract Since the mid-1970s, ENSO has changed in character to a predominance of El Niño conditions, the extreme phase of which appears coincidental with increases in global temperature records. Instrumental time series (<150 years) are too short to adequately address the significance of late twentieth-century ENSO variability, thus, multi-century palaeoclimate reconstructions derived from long proxy records are sought. Despite the global influence exerted by ENSO on society, limited consensus exists within the scientific community as to which index best defines the timing, duration and strength of events. Here we address issues associated with the complexity of ENSO characterisation by comparing the ,event capture' ability of two currently used indices of ENSO. It is suggested that the use of a sole ENSO index is undesirable as a given index is only indicative of one physical aspect of the phenomenon, and as such is unlikely to be representative of the wider interactions experienced in the coupled ocean-atmospheric system. In an attempt to describe more of the nature and evolution of ENSO events, the Coupled ENSO Index (CEI) classification scheme was devised to identify synchronous oceanic (Niño 3.4 SST) and atmospheric (Southern Oscillation Index) anomalies associated with ENSO for the instrumental period (1871,2003). The CEI is of practical relevance to the ENSO community as it provides an amplitude preserving instrumental baseline for the calibration of proxy records to reconstruct both components of the ENSO system. Analysis of the nature of instrumental ENSO events from the CEI suggests that the frequency and intensity of post-1970 ENSO events (when 50% of all extreme events identified occur) appears the most anomalous in the context of at least the past century. It is hoped that the CEI will facilitate palaeo-ENSO research to systematically resolve the long-term context of past ENSO behaviour to assess whether the apparently anomalous nature of late twentieth-century variability is unprecedented within existing palaeoclimate archives. Copyright © 2005 Royal Meteorological Society. [source] Spatial analysis of climate in winegrape-growing regions in AustraliaAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2010A. HALL Abstract Background and Aims:, Temperature-based indices are commonly used to indicate long-term suitability of climate for commercially viable winegrape production of different grapevine cultivars, but their calculation has been inconsistent and often inconsiderate of within-region spatial variability. This paper (i) investigates and quantifies differences between four such indices; and (ii) quantifies the within-region spatial variability for each Australian wine region. Methods and Results:, Four commonly used indices describing winegrape growing suitability were calculated for each Australian geographic indication (GI) using temperature data from 1971 to 2000. Within-region spatial variability was determined for each index using a geographic information system. The sets of indices were compared with each other using first- and second-order polynomial regression. Heat-sum temperature indices were strongly related to the simple measure of mean growing season temperature, but variation resulted in some differences between indices. Conclusion:, Temperature regime differences between the same region pairs varied depending upon which index was employed. Spatial variability of the climate indices within some regions led to significant overlap with other regions; knowledge of the climate distribution provides a better understanding of the range of cultivar suitability within each region. Significance of the Study:, Within-region spatial variability and the use of different indices over inconsistent time periods to describe temperature regimes have, before now, made comparisons of climates between viticulture regions difficult. Consistent calculations of indices, and quantification of spatial variability, enabled comparisons of Australian GIs to be made both within Australia and with American Viticultural Areas in the western United States. [source] Lipids, lipid modifying agents and cardiovascular risk: a review of the evidenceCLINICAL ENDOCRINOLOGY, Issue 6 2009David Preiss Summary It is well-established that serum total-cholesterol, LDL-cholesterol, low HDL-cholesterol and calculated indices such as total cholesterol : HDL-cholesterol ratio or less commonly used indices such as non-HDL cholesterol are strongly predictive of cardiovascular events. Serum triglycerides, by contrast, are only modestly associated with coronary heart disease (CHD) in multivariate analysis and incorporation of triglycerides into prediction algorithms is therefore unlikely to improve their prediction capability. Meta-analysis of studies including > 90 000 subjects has provided robust evidence that statins reduce important clinical end-points. These included a 12% fall in all-cause mortality, 19% fall in CHD mortality and 23% fall in CHD mortality or myocardial infarction. Furthermore there are high quality data showing additional benefit of intensive statin therapy over standard statin therapy for secondary prevention of cardiovascular disease. However, meta-analysis of 10 fibrate trials has shown inconsistent evidence of vascular benefit and non-cardiovascular mortality has been slightly but consistently elevated in most fibrate trials and in meta-analysis. The general use of fibrates for cardiovascular risk reduction can therefore not be supported at present. Other second line agents such as bile acid sequestrants, nicotinic acid and omega-3 fatty acid supplements have been evaluated in a few randomized controlled studies in which cardiovascular benefit has been found but clearly further data are required to properly establish their use in clinical practice. Ongoing studies such as ACCORD, IMPROVE-IT, ASCEND, ORIGIN and HPS2-THRIVE should assist in answering outstanding questions over the next 5 years. [source] | ||||||||||