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Anomalous dielectric response of very small quantities of virgin, aged and failed silicone oil
A technique is described for making dielectric spectroscopy measurements of very small quantities (<1μl) of oil. The technique utilises surface tension to hold the oil between the plates of a capacitor, the inter-electrode distance being controlled by a micrometer. Breakdown strength can also be estimated using this technique. Three samples of silicone oil, used in cable sealing ends, were tested: virgin, used and failed. A major component in the frequency dependent impedance had the form Z(ω)=B(1-b)(iω)/sup.1-p/). This component was interpreted in terms of a fractal percolation model, and the anomalous thickness dependence predicted by the model verified by varying the inter-electrode distance. The difference observed for the three different samples indicate that conducting contaminants are responsible for the percolation system
Sawing Recovery of Several Sawmills in Jepara
In the situation of wood material shortage, it is important to furniture manufacturers to efficiently utilize the wood. Increasing efficiency for improving value added of small medium enterprises of wood furniture industries in Jepara should be carried out from the first stage in wood processing: sawing that will convert logs into sawn timber. A study has been carried out on improving sawing recovery of sawntimber by live-sawing pattern to make loseware lumber for furniture material in Jepara region. This study was done by investigating the current sawing recovery data as determined during one full day's processing at each of the four bandsaw mill facilities and one chainsaw/carving facility. The results indicate that the current recovery rate of sawmilling services companies in Jepara reached 70 - 80 %. These recoveries are relatively high due to the live sawing pattern used and the fact that sawn boards were not edged or resawn into square pieces at the mill. Compared to existing rules and the Government standard for calculating the recovery rate, sawmilling service companies in Jepara have practiced efficient processing in sawing
Abstracts in high profile journals often fail to report harm
<p>Abstract</p> <p>Background</p> <p>To describe how frequently harm is reported in the abstract of high impact factor medical journals.</p> <p>Methods</p> <p><it>Design and population</it>: We carried out a blinded structured review of a random sample of 363 Randomised Controlled Trials (RCTs) carried out on human beings, and published in high impact factor medical journals in 2003. <it>Main endpoint</it>: 1) Proportion of articles reporting harm in the abstract; and 2) Proportion of articles that reported harm in the abstract when harm was reported in the main body of the article. <it>Analysis</it>: Corrected Prevalence Ratio (cPR) and its exact confidence interval were calculated. Non-conditional logistic regression was used.</p> <p>Results</p> <p>363 articles and 407 possible comparisons were studied. Overall, harm was reported in 135 abstracts [37.2% (CI95%:32.2 to 42.4)]. Harm was reported in the main text of 243 articles [66.9% (CI95%: 61.8 to 71.8)] and was statistically significant in 54 articles [14.9% (CI95%: 11.4 to 19.0)]. Among the 243 articles that mentioned harm in the text, 130 articles [53.5% (CI95% 47.0 to 59.9)] reported harm in the abstract; a figure that rose to 75.9% (CI95%: 62.4 to 86.5) when the harm reported in the text was statistically significant. Harm in the abstract was more likely to be reported when statistically significant harm was reported in the main body of the article [cPR = 1.70 (CI95% 1.47 to 1.92)] and when drug companies (not public institutions) funded the RCTs [cPR = 1.29 (CI95% 1.03 to 1.67)].</p> <p>Conclusion</p> <p>Abstracts published in high impact factor medical journals underreport harm, even when harm is reported in the main body of the article.</p
Assessment of the Quality of Reporting in Abstracts of Randomized Controlled Trials Published in Five Leading Chinese Medical Journals
BACKGROUND: Clear, transparent and sufficiently detailed abstracts of randomized trials (RCTs), published in journal articles are important because readers will often base their initial assessment of a trial on such information. However, little is known about the quality of reporting in abstracts of RCTs published in medical journals in China. METHODS: We identified RCTs abstracts from 5 five leading Chinese medical journals published between 1998 and 2007 and indexed in MEDLINE. We assessed the quality of reporting of these abstracts based on the Consolidated Standards of Reporting Trials (CONSORT) abstract checklist. We also sought to identify whether any differences exist in reporting between the Chinese and English language version of the same abstract. RESULTS: We identified 332 RCT abstracts eligible for examination. Overall, the abstracts we examined reported 0-8 items as designated in the CONSORT checklist. On average, three items were reported per abstract. Details of the interventions (288/332; 87%), the number of participants randomized (216/332; 65%) and study objectives (109/332; 33%) were the top three items reported. Only two RCT abstracts reported details of trial registration, no abstracts reported the method of allocation concealment and only one mentioned specifically who was blinded. In terms of the proportion of RCT abstracts fulfilling a criterion, the absolute difference (percentage points) between the Chinese and English abstracts was 10% (ranging from 0 to 25%) on average, per item. CONCLUSIONS: The quality of reporting in abstracts of RCTs published in Chinese medical journals needs to be improved. We hope that the introduction and endorsement of the CONSORT for Abstracts guidelines by journals reporting RCTs will lead to improvements in the quality of reporting
Racial Differences in Tuberculosis Infection in United States Communities: The Coronary Artery Risk Development in Young Adults Study
Previously reported associations between race/ethnicity and tuberculosis infection have lacked sufficient adjustment for socioeconomic factors. We analyzed race/ethnicity and self-reported tuberculosis infection data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a well-characterized cohort of 5115 black and white participants, and found that after adjusting for sociodemographic and clinical factors, black participants were more likely to report tuberculosis infection and/or disease (odds ratio, 2.0; 95% confidence interval, 1.5–2.9)
Variable host-pathogen compatibility in Mycobacterium tuberculosis.
Mycobacterium tuberculosis remains a major cause of morbidity
and mortality worldwide. Studies have reported human pathogens
to have geographically structured population genetics, some of
which have been linked to ancient human migrations. However, no
study has addressed the potential evolutionary consequences of
such longstanding human–pathogen associations. Here, we demonstrate
that the global population structure of M. tuberculosis is
defined by six phylogeographical lineages, each associated with
specific, sympatric human populations. In an urban cosmopolitan
environment, mycobacterial lineages were much more likely to
spread in sympatric than in allopatric patient populations. Tuberculosis
cases that did occur in allopatric hosts disproportionately
involved high-risk individuals with impaired host resistance. These
observations suggest that mycobacterial lineages are adapted to
particular human populations. If confirmed, our findings have
important implications for tuberculosis control and vaccine development
CONSORT 2010 Statement: Updated Guidelines for Reporting Parallel Group Randomised Trials
Kenneth Schulz and colleagues describe the 2010 version of the CONSORT Statement, which updates the previous reporting guideline based on new methodological evidence and accumulated experience
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