267 research outputs found

    Statistical properties of online auctions

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    We characterize the statistical properties of a large number of online auctions run on eBay. Both stationary and dynamic properties, like distributions of prices, number of bids etc., as well as relations between these quantities are studied. The analysis of the data reveals surprisingly simple distributions and relations, typically of power-law form. Based on these findings we introduce a simple method to identify suspicious auctions that could be influenced by a form of fraud known as shill bidding. Furthermore the influence of bidding strategies is discussed. The results indicate that the observed behavior is related to a mixture of agents using a variety of strategies.Comment: 9 pages, 4 figures, to be published in Int. J. Mod. Phys.

    Occult intraspinal abnormalities and congenital scoliosis

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    Background: Congenital scoliosis occurs because of either the failure of formation or the failure of segmentation or both. Evaluation of the incidence and the types of occult intraspinal abnormalities in congenital scoliosis is the subject of this study. Methods: During a period of 29 years, 103 patients with congenital scoliosis were studied. MRI was used in 46 patients, myelography or CT myelography was used in 64 patients and both MRI and myelography or CT myelography were used in 7 patients for intraspinal abnormalities. Results: In the MRI group, among the 46 patients, 19 patients (41.3) had intraspinal abnormalities consisting syringomyelia in 9 (19.5) diastematomyelia in 8 (17.4), tethered cord syndrome in 6 (13), low conus in 5 (10.8) and diplomyelia in 3 (6.5) of the patients. In the myelography group, among the 64 patients, 17 (26.5) had intraspinal abnormalities and diastematomyelia was the most common one found in 14 (21.8) patients. Conclusions: Intraspinal abnormalities are frequent in congenital scoliosis. Syringomyelia may be associated with congenital scoliosis. In congenital scoliosis, rib fusion may be an indicator of intraspinal abnormalities in MRI. A significant difference between clinical findings and intraspinal anomalies (P<0.05) was noted. Moreover, we believe that total spinal MRI with coronal, sagittal and axial views is a valuable tool in determining the intraspinal abnormalities in congenital scoliosis. This method is highly recommended for detection and neurosurgical intervention before corrective surgeries

    Left Atrial Reservoir Function and Outcomes in Secondary Mitral Regurgitation

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    BackgroundLeft atrial (LA) size is a marker of disease severity and is related to worse outcomes in secondary mitral regurgitation (MR). The prognostic value of LA function assessed by LA reservoir strain (LARS), however, remains unknown. The aim of this study was to investigate the prognostic implications of LARS in patients with significant secondary MR.MethodsLARS was evaluated using speckle-tracking echocardiography in patients with more than mild (grade ≥ 2) secondary MR. The population was divided into two groups according to the median LARS value (9.8%). The primary end point was all-cause mortality.ResultsA total of 666 patients (mean age, 66 ± 11 years; 68% men) were included. On multivariable analysis, more severe MR was independently associated with more impaired LARS (LARS P = .001). During a median follow-up period of 5 years (interquartile range, 2-10), 383 patients (58%) died. Patients with LARS P P ConclusionsLARS is independently associated with all-cause mortality in patients with significant secondary MR and has incremental prognostic value over LA volume and left ventricular global longitudinal strain. LARS may improve risk stratification of patients with secondary MR.</p

    Plasma concentration of Propionibacterium acnes antibodies and prostate cancer risk: results from an Australian population-based case–control study

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    Background:Recent studies in prostatic tissue suggest that Propionibacterium acnes (P. acnes), a bacterium associated with acne that normally lives on the skin, is the most prevalent bacterium in the prostate and in men with benign prostatic hyperplasia. Its prevalence is higher in samples from patients subsequently diagnosed with prostate cancer. The aim of our study was to test whether circulating levels of P. acnes antibodies are associated with prostate cancer risk and tumour characteristics using plasma samples from a population-based case-control study.Methods:We measured plasma concentration of P. acnes antibodies for 809 cases and 584 controls using a recently developed ELISA assay. We compared antibody titres between cases and controls using unconditional logistic regression adjusted for batch and variables associated with the study design (i.e., age, year of selection and centre). The primary analysis included P. acnes titres in the model as a dichotomous variable using the median value for controls as the cut-off value.Results:P. acnes antibody titres for both cases and controls ranged from 1: 16 (i.e., low concentration) to 1: 65 536 (i.e., high concentration; median value1: 1024). The odds ratio for prostate cancer associated with titres at or above the median value was 0.73 (95% CI 0.58-0.91, P0.005). The association appeared to be particularly strong for advanced prostate cancer (AJCC Stage grouping III-IV) for which the odds ratio was 0.59 (95% CI 0.43-0.81, P0.001) but there was insufficient evidence that the association differed by tumour stage (p heterogeneity0.07).Conclusion: These results need to be confirmed in prospective studies but they are consistent with the hypothesis that P. acnes has a role in prostate cancer. © 2010 Cancer Research UK All rights reserved

    Ginkgo biloba for the treatment of vitilgo vulgaris: an open label pilot clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Vitiligo is a common hypopigmentation disorder with significant psychological impact if occurring before adulthood. A pilot clinical trial to determine the feasibility of an RCT was conducted and is reported here.</p> <p>Methods</p> <p>12 participants 12 to 35 years old were recruited to a prospective open-label pilot trial and treated with 60 mg of standardized <it>G. biloba </it>two times per day for 12 weeks. The criteria for feasibility included successful recruitment, 75% or greater retention, effectiveness and lack of serious adverse reactions. Effectiveness was assessed using the Vitiligo Area Scoring Index (VASI) and the Vitiligo European Task Force (VETF), which are validated outcome measures evaluating the area and intensity of depigmentation of vitiligo lesions. Other outcomes included photographs and adverse reactions. Safety was assessed by serum coagulation factors (platelets, PTT, INR) at baseline and week 12.</p> <p>Results</p> <p>After 2 months of recruitment, the eligible upper age limit was raised from 18 to 35 years of age in order to facilitate recruitment of the required sample size. Eleven participants completed the trial with 85% or greater adherence to the protocol. The total VASI score improved by 0.5 (P = 0.021) from 5.0 to 4.5, range of scale 0 (no depigmentation) to 100 (completely depigmented). The progression of vitiligo stopped in all participants; the total VASI indicated an average repigmentation of vitiligo lesions of 15%. VETF total vitiligo lesion area decreased 0.4% (P = 0.102) from 5.9 to 5.6 from baseline to week 12. VETF staging score improved by 0.7 (P = 0.101) from 6.6 to 5.8, and the VETF spreading score improved by 3.9 (P < 0.001)) from 2.7 to -1.2. There were no statistically significant changes in platelet count, PTT, or INR.</p> <p>Conclusions</p> <p>The criteria for feasibility were met after increasing the maximum age limit of the successful recruitment criterion; participant retention, safety and effectiveness criteria were also met. Ingestion of 60 mg of <it>Ginkgo biloba </it>BID was associated with a significant improvement in total VASI vitiligo measures and VETF spread, and a trend towards improvement on VETF measures of vitiligo lesion area and staging. Larger, randomized double-blind clinical studies are warranted and appear feasible.</p> <p>Trial Registration</p> <p>Clinical trials.gov registration number <a href="http://www.clinicaltrials.gov/ct2/show/NCT00907062">NCT00907062</a></p

    Developing "Code of Ethics for Medical Professionals, Medical Council of Islamic Republic of Iran"

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    Background: The medical profession has always been an inspiration for human societies throughout its diverse history. This position and historical authority in the field of ethics has had a different and higher status, in such a way that many of the norms of general ethics and professional ethics, especially principles, such as trust, confidentiality and respect for human dignity, have been developed by medical professionals. Developing guidelines of general and professional ethics is one of the inherent duties of the Medical Council of the Islamic Republic of Iran (IRIMC) as a professional organization. In this regard, the Supreme Council of IRIMC has approved the "Code of Ethics for Medical Professionals"and, in accordance with its legal authority, has annexed it to the disciplinary regulations of IRIMC. Methods: A draft document, the result of extensive literature review, was discussed in 27 expert panel meetings and after receiving and endorsing the stakeholders' point of view, was approved by the IRIMC Supreme Council. Results: The first edition of "Code of Ethics for Medical Professionals, Medical Council of Islamic Republic of Iran"was developed on July 6, 2017 by the Supreme Council of IRIMC. The guideline was set to take effect one year after its enactment. The first edition was revised and completed and final edition was adopted on August 9, 2018 by IRIMC in 13 chapters and 140 articles (original full text is available in the Supplementary file 1). Conclusion: According to the approved decision by the Supreme Council of IRIMC on May 10, 2018, the final edition takes effect as of October 7, 2018. © 2020 The Author(s)
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