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Distribution by Scientific Domains

Medical Sciences	50%
Humanities and Social Sciences	50%

Selected Abstracts

Osteitis condensans ilii: a significant association with sacroiliac joint tenderness in women

INTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 1 2009
Katey JENKS
Abstract Aim:, To determine whether subjects with radiological evidence of osteitis condensans ilii exhibit symptoms and signs in common with sacroiliitis when compared with an age-matched control group and to examine demographic features. Methods:, The Dunedin Hospital radiology database was searched for all subjects with changes of osteitis condensans ilii over a 10-year period. An age-matched control group with plain X-rays of the pelvis was recruited from the same database. All subjects were sent a questionnaire enquiring about back pain and details of previous pregnancies. Those who responded to the questionnaire were invited for clinical assessment. Results:, Thirty-five individuals with osteitis condensans ilii were identified over the 10-year period. All were female and reported prior pregnancy supporting an association between osteitis condensans ilii and pregnancy. Stress testing of the sacroiliac joints was associated with greater tenderness in the osteitis condensans ilii group with a mean of 1.8 positive tests out of a possible 4, compared to 0.8 in the control group (Wilcoxon rank-sum test P = 0.02). Comparison between the two groups showed no difference in number of pregnancies, newborn weight, presence of back pain, back pain assessed by the Oswestry Low Back Pain Questionnaire or loss of function using the Bath Ankylosing Spondylitis Functional Index (BASFI). Conclusion:, Osteitis condensans ilii is associated with tenderness during sacroiliac joint compression tests and should be considered in the differential diagnosis when sacroiliac joint tenderness is elicited. [source]

OLS ESTIMATION AND THE t TEST REVISITED IN RANK-SIZE RULE REGRESSION,

JOURNAL OF REGIONAL SCIENCE, Issue 4 2008
Yoshihiko Nishiyama
ABSTRACT The rank-size rule and Zipf's law for city sizes have been traditionally examined by means of OLS estimation and the t test. This paper studies the accurate and approximate properties of the OLS estimator and obtains the distribution of the t statistic under the assumption of Zipf's law (i.e., Pareto distribution). Indeed, we show that the t statistic explodes asymptotically even under the null, indicating that a mechanical application of the t test yields a serious type I error. To overcome this problem, critical regions of the t test are constructed to test the Zipf's law. Using these corrected critical regions, we can conclude that our results are in favor of the Zipf's law for many more countries than in the previous researches such as Rosen and Resnick (1980) or Soo (2005). By using the same database as that used in Soo (2005), we demonstrate that the Zipf law is rejected for only one of 24 countries under our test whereas it is rejected for 23 of 24 countries under the usual t test. We also propose a more efficient estimation procedure and provide empirical applications of the theory for some countries. [source]

Parkinson's disease, stroke, and related epidemiology

MOVEMENT DISORDERS, Issue 11 2005
Andrew Nataraj MD
Abstract We investigated the prevalence of cerebrovascular disease and other comorbidities in Parkinson's disease (PD) patients compared to the general population. Five hundred PD patients were chosen randomly from one author's (A.H.R.) database. Age- and sex-matched controls were derived from 270 patients with essential tremor from the same database and from 490 patients in a general practitioner's database. Age, hypertensive status, smoking status, coronary artery disease, orthostatic hypotension, diabetes mellitus, and symptomatic cerebrovascular disease (stroke or transient ischemic attack) were assessed. Statistical analysis was performed using Pearson ,2 testing and binary logistic regression analysis. The prevalence of coronary artery disease, hypertension, diabetes mellitus, and orthostatic hypotension was similar among groups. The PD group had more patients who never smoked and less current smokers than the other groups. While there were similar frequencies of symptomatic cerebrovascular disease among groups, the prevalence of stroke was lower in PD patients. This difference disappeared upon stratification into groups based on smoking status and in the addition of smoking as a covariate in the multivariate analysis. Diminished smoking in PD patients likely plays a role in our finding of decreased stroke in patients with PD. Increased access to appropriate neurological care and subsequent prevention of stroke after a warning transient ischemic attack may also play a role, as may diminished levels of excitotoxic neurotransmitters in PD patients. © 2005 Movement Disorder Society [source]

The benefits of skimming in data fusion

PROCEEDINGS OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE & TECHNOLOGY (ELECTRONIC), Issue 1 2007
Anselm Spoerri
Data fusion methods commonly use and compare all the documents returned by multiple retrieval systems to create a new result list. On the one hand, as documents further down in the result lists are considered, a document's probability of being relevant decreases significantly. On the other hand, retrieval systems tend to find similar relevant documents when searching the same database, but they do not find them in the same rank positions. Thus, data fusion methods need to consider all of the documents returned by the retrieval systems. Using TREC 3, 6, 7, 8, 12 and 13 data, this paper examines how "skimming", where the number of documents examined in the result lists is gradually increased, can help to identify relevant documents. It is shown that "gradual skimming" and what can be learned as the list depth is increased can help to improve the retrieval effectiveness of data fusion methods. [source]