351 research outputs found

    Combinatorial Voter Control in Elections

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    Voter control problems model situations such as an external agent trying to affect the result of an election by adding voters, for example by convincing some voters to vote who would otherwise not attend the election. Traditionally, voters are added one at a time, with the goal of making a distinguished alternative win by adding a minimum number of voters. In this paper, we initiate the study of combinatorial variants of control by adding voters: In our setting, when we choose to add a voter~vv, we also have to add a whole bundle Îş(v)\kappa(v) of voters associated with vv. We study the computational complexity of this problem for two of the most basic voting rules, namely the Plurality rule and the Condorcet rule.Comment: An extended abstract appears in MFCS 201

    Clinical risk factor assessment had better discriminative ability than bone mineral density in identifying subjects with vertebral fracture

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    Summary: This study evaluated the characteristics of patients with vertebral fractures and examined the discriminative ability of clinical risk factors. The findings provide further insights into possible development of a simple, cost-effective scheme for fracture risk assessment using clinical risk factors to identify high-risk patients for further evaluation. Introduction: Vertebral fractures are the most common complication of osteoporosis. The aim of this study was to evaluate the characteristics of patients with vertebral fractures and to determine the discriminative ability of bone mineral density (BMD) and other clinical risk factors. Methods: Postmenopausal Southern Chinese women (2,178) enrolled in the Hong Kong Osteoporosis Study since 1995 were prospectively followed up for fracture outcome. Subjects (1,372) with lateral spine radiographs were included in this study. Baseline demographic, BMD, and clinical risk factor information were obtained from a structured questionnaire. Results: Subjects (299; 22%) had prevalent vertebral fractures. The prevalence of vertebral fractures increased with increasing age, number of clinical risk factors, and decreasing BMD. The odds of having a prevalent vertebral fracture per SD reduction in BMD after adjustment for age in Hong Kong Southern Chinese postmenopausal women was 1.5 for the lumbar spine and femoral neck. Analysis of the receiver operating characteristic curve revealed that bone mineral apparent density did not enhance fracture risk prediction. Subjects with ≥4 clinical risk factors had 2.3-fold higher odds of having a prevalent vertebral fracture while subjects with ≥4 clinical risk factors plus a low BMD (i.e., femoral neck T-score <-2.5) had 2.6-fold. Addition of BMD to clinical risk factors did not enhance the discriminative ability to identify subjects with vertebral fracture. Conclusions: Based on these findings, we recommend that screening efforts should focus on older postmenopausal women with multiple risk factors to identify women who are likely to have a prevalent vertebral fracture. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

    The Consolidation of the White Southern Congressional Vote

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    This article explores the initial desertion and continued realignment of about one-sixth of the white voters in the South who, until 1994, stood by Democratic congressional candidates even as they voted for Republican presidential nominees. Prior to 1994, a sizable share of the white electorate distinguished between Democratic congressional and presidential candidates; since 1994 that distinction has been swept away. In 1992, a majority of white southern voters was casting their ballot for the Democratic House nominee; by 1994, the situation was reversed and 64 percent cast their ballot for the Republican. Virtually all categories of voters increased their support of Republican congressional candidates in 1994 and the following elections further cement GOP congressional support in the South. Subsequent elections are largely exercises in partisanship, as the congressional votes mirror party preferences. Republicans pull nearly all GOP identifiers, most independents, and a sizeable minority of Democratic identifiers. Democrats running for Congress no longer convince voters that they are different from their party’s presidential standard bearers—a group that has consistently been judged unacceptable to overwhelming proportions of the southern white electorate.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Periferne osteoporotske frakture osim kuka - epidemiologija i znaÄŤenje

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    Fractures are the most serious consequence of osteoporosis. Non-vertebral and non-hip fractures are seldom recognised as important, even though they account for the majority of all fractures. The most prevalent localisations are distal radius, proximal humerus, ribs, clavicle, and the pelvis. According to the results from large phase III clinical trials for placebo groups, their incidence ranges from 4.9 % to 12.0 %. Hospital morbidity data in Croatia in 2006 show that peripheral non-hip fractures ranked among the leading fifteen injuries, accounting for 23.7 % of all injuries in patients aged 60 years and above. Risk factors for non-hip and non-vertebral fractures are similar to other osteoporotic fractures, and the main are low bone mineral density and earlier fractures. Quality of life is considerably affected by these fractures, and medical costs are very high, soaring as high as 36.9 % of all national medical costs in the USA. Nonvertebral non-hip fractures need more attention, which was also recognised by the European regulatory bodies that approve use of anti-osteoporotic drugs.Prijelomi su najozbiljnija posljedica osteoporoze. Iako čine većinu svih fraktura, nevertebralne frakture osim kuka rijetko se prepoznaju kao značajne. Najčešće lokalizacije tih prijeloma su: distalni dio radijusa, proksimalni dio humerusa, rebra, klavikula i zdjelica. Prema rezultatima iz placebo-grupa III. faze velikih kliničkih ispitivanja raspon njihove incidencije iznosi između 4,9 % i 12,0 %. Prema podacima bolničkog pobolijevanja za 2006. g. u Hrvatskoj, među 15 vodećih ozljeda u dobnoj grupi 60 i više godina 23,7 % bile su periferne frakture osim kuka. Čimbenici rizika za nevertebralne frakture osim onih kuka slični su kao i za druge osteoporotske frakture gdje središnje mjesto imaju niska mineralna gustoća kosti i prethodne frakture. Ove frakture imaju velik utjecaj na kvalitetu `ivota, a njihovi su troškovi vrlo visoki, tako da u SAD-u iznose čak 36.9 % svih nacionalnih medicinskih troškova. Nevertebralne frakture osim kuka zahtijevaju veću pozornost, što su i prepoznala europska regulatorna tijela koja odobravaju upotrebu antiosteoporotskih lijekova

    Temporal Trends in Vertebral Size and Shape from Medieval to Modern-Day

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    Human lumbar vertebrae support the weight of the upper body. Loads lifted and carried by the upper extremities cause significant loading stress to the vertebral bodies. It is well established that trauma-induced vertebral fractures are common especially among elderly people. The aim of this study was to investigate the morphological factors that could have affected the prevalence of trauma-related vertebral fractures from medieval times to the present day. To determine if morphological differences existed in the size and shape of the vertebral body between medieval times and the present day, the vertebral body size and shape was measured from the 4th lumbar vertebra using magnetic resonance imaging (MRI) and standard osteometric calipers. The modern samples consisted of modern Finns and the medieval samples were from archaeological collections in Sweden and Britain. The results show that the shape and size of the 4th lumbar vertebra has changed significantly from medieval times in a way that markedly affects the biomechanical characteristics of the lumbar vertebral column. These changes may have influenced the incidence of trauma- induced spinal fractures in modern populations

    Ethnic difference of clinical vertebral fracture risk

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    Vertebral fractures are the most common osteoporotic fractures. Data on the vertebral fracture risk in Asia remain sparse. This study observed that Hong Kong Chinese and Japanese populations have a less dramatic increase in hip fracture rates associated with age than Caucasians, but the vertebral fracture rates were higher, resulting in a high vertebral-to-hip fracture ratio. As a result, estimation of the absolute fracture risk for Asians may need to be readjusted for the higher clinical vertebral fracture rate. Introduction: Vertebral fractures are the most common osteoporotic fractures. Data on the vertebral fracture risk in Asia remain sparse. The aim of this study was to report the incidence of clinical vertebral fractures among the Chinese and to compare the vertebral-to-hip fracture risk to other ethnic groups. Methods: Four thousand, three hundred eighty-six community-dwelling Southern Chinese subjects (2,302 women and 1,810 men) aged 50 or above were recruited in the Hong Kong Osteoporosis Study since 1995. Baseline demographic characteristics and medical history were obtained. Subjects were followed annually for fracture outcomes with a structured questionnaire and verified by the computerized patient information system of the Hospital Authority of the Hong Kong Government. Only non-traumatic incident hip fractures and clinical vertebral fractures that received medical attention were included in the analysis. The incidence rates of clinical vertebral fractures and hip fractures were determined and compared to the published data of Swedish Caucasian and Japanese populations. Results: The mean age at baseline was 62 ± 8.2 years for women and 68 ± 10.3 years for men. The average duration of follow-up was 4.0 ± 2.8 (range, 1 to 14) years for a total of 14,733 person-years for the whole cohort. The incidence rate for vertebral fracture was 194/100,000 person-years in men and 508/100,000 person-years in women, respectively. For subjects above the age of 65, the clinical vertebral fracture and hip fracture rates were 299/100,000 and 332/100,000 person-years, respectively, in men, and 594/100,000 and 379/100,000 person-years, respectively, in women. Hong Kong Chinese and Japanese populations have a less dramatic increase in hip fracture rates associated with age than Caucasians. At the age of 65 or above, the hip fracture rates for Asian (Hong Kong Chinese and Japanese) men and women were less than half of that in Caucasians, but the vertebral fracture rate was higher in Asians, resulting in a high vertebral-to-hip fracture ratio. Conclusions: The incidences of vertebral and hip fractures, as well as the vertebral-to-hip fracture ratios vary in Asians and Caucasians. Estimation of the absolute fracture risk for Asians may need to be readjusted for the higher clinical vertebral fracture rate. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

    Progressive vertebral deformities despite unchanged bone mineral density in patients with sarcoidosis: a 4-year follow-up study

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    To evaluate the incidence of new and/or progressive vertebral deformities and changes in bone mineral density, we re-examined 66 patients with sarcoidosis after a follow-up period of four years. In 17 subjects (26%) new and/or progressive vertebral deformities were found, though BMD did not change significantly. INTRODUCTION: Previous studies from our group have shown that morphometric vertebral deformities suggestive of fractures can be found in 20% of patients with sarcoidosis, despite a normal bone mineral density (BMD). The aim of this study was to determine the incidence of new and/or progressive vertebral deformities and the evolution of BMD during the course of this disease. METHODS: BMD of the hip (DXA) and vertebral fracture assessment (VFA) with lateral single energy densitometry was performed at baseline and after 45 months in 66 patients with sarcoidosis. Potential predictors of new/ progressive vertebral deformities were assessed using logistic regression analysis. RESULTS: The BMD of the total group was unchanged after follow-up. The prevalence of vertebral deformities increased from 20 to 32% (p < 0.05); in 17 subjects (26%) new or progressive vertebral deformities were diagnosed. A lower T-score of the femoral neck [(OR = 2.5 (CI: 1.0-5.9), p < 0.05)] and mother with a hip fracture [(OR = 14.1 (CI: 1.4-142.6), p < 0.05)] were independent predictors of new/progressive deformities. CONCLUSIONS: In subjects with sarcoidosis the number of vertebral deformities increases in the course of this disease, despite unchanged BMD. The combination of low normal BMD and family history of fragility fractures confers an increased risk of the incidence of these deformities

    Search for the glueball candidates f0(1500) and fJ(1710) in gamma gamma collisions

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    Data taken with the ALEPH detector at LEP1 have been used to search for gamma gamma production of the glueball candidates f0(1500) and fJ(1710) via their decay to pi+pi-. No signal is observed and upper limits to the product of gamma gamma width and pi+pi- branching ratio of the f0(1500) and the fJ(1710) have been measured to be Gamma_(gamma gamma -> f0(1500)). BR(f0(1500)->pi+pi-) < 0.31 keV and Gamma_(gamma gamma -> fJ(1710)). BR(fJ(1710)->pi+pi-) < 0.55 keV at 95% confidence level.Comment: 10 pages, 3 figure
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