Impact height and wall distance in bloodstain pattern analysis—what patterns of round bloodstains can tell us

International Journal of Legal Medicine September 2014
Bloodstain pattern analysis is a routine procedure in forensic cases that involve bleeding wounds. It utilizes geometric principles to determine the sequence of actions causing the bloodshed and the area of origin, that is, from where the blood originated. The patterns formed by circular bloodstains from drops of blood that hit adjacent surfaces at a 90-degree angle are thought to provide indications of the height of the impact. In this study, blunt force exerted against a pool of blood, which was used as a surrogate for a bleeding wound, was carried out for five different impact-to-wall distances. The blunt force consisted of a hammer head that was dropped from a height of 1.5 m. High-speed photography of the impact and trajectories of the projected blood droplets was analysed. The patterns containing bloodstains produced by the droplets were analysed by measuring the circular bloodstains within the patterns. All the experiments showed that there were two distinct patterns or clusters of circular bloodstains that occurred at different heights above the impact site. The two patterns were a result of different fractions of blood that were projected in a garland or crown-like form of a “Worthington splash” after impact. The findings suggest that patterns of circular bloodstains cannot be used as direct indicators of impact height, but combined analysis of their clusters may lead to indirect determination of impact-to-wall distance and area of origin.

The association between serum selenium and gestational diabetes mellitus: A systematic review and meta-analysis

Journal of Trace Elements in Medicine and Biology Available online 16 September 2014;  DOI: 10.1016/j.jtemb.2014.09.006

Background

Results of the studies about association between serum selenium concentration and gestational hyperglycemia are inconsistent. Some studies have demonstrated that women with gestational diabetes mellitus (GDM) have lower Se concentrations while contrary results are reported in other studies.

Aim

The aim of this study is to compare the serum Se concentration in women with GDM and normoglycemic pregnant women via a systematic review and meta-analysis.

Methods

A computerized literature search on four databases (PubMed, Cochrane register of control trials, Scopus and Google scholar) was performed from inception through August 2013. Necessary data were extracted and random effects model was used to conduct the meta-analysis.

Results

Six observational studies (containing 147 women with GDM and 360 normoglycemic pregnant women) were found, which had compared serum Se concentration in women suffering from GDM with normal pregnant ones. Our meta-analysis revealed that serum Se concentration was lower in women with GDM compared to normoglycemic pregnant women (Hedges = -1.34; 95% CI: -2.33–- 0.36; P< 0.01). Stratified meta-analysis demonstrated that concentration of Se in the sera of women with GDM was lower than normal pregnant women both in second and third trimesters, but the result was not significant in second trimester (second trimester: Hedges = – 0.68; 95% CI: – 1.60–0.25; P = 0.15, third trimester: Hedges = – 2.81; 95% CI: – 5.21–- 0.42; P< 0.05). It was also demonstrated that serum Se status was lower in pregnant women with impaired glucose tolerance (IGT) compared to normoglycemic pregnant women (Hedges = – 0.85; 95% CI: -1.18–-0.52).

Conclusion

The available evidences suggest that serum Se concentration is significantly lower in pregnant women with gestational hyperglycemia compared to normal pregnant women.

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Headspace gas chromatography with flame ionization detection (HS-GC-FID) for the determination of dissolved methane in wastewater

Water Science & Technology Vol 70 No 5 pp 901–908 © CSIRO 2014 doi:10.2166/wst.2014.298

There is currently a need for a simple, accurate and reproducible method that quantifies the amount of dissolved methane in wastewater in order to realize the potential methane that can be recovered and account for any emissions. This paper presents such a method, using gas chromatography with flame ionization detection fitted with a GS-Gas PRO column coupled with a headspace auto sampler. A practical limit of detection for methane of 0.9 mg L−1, with a retention time of 1.24 min, was obtained. It was found that the reproducibility and accuracy of the method increased significantly when samples were collected using an in-house constructed bailer sampling device and with the addition of 100 μL hydrochloric acid (HCl) and 25% sodium chloride (NaCl) and sonication for 30 min prior to analysis. Analysis of wastewater samples and wastewater sludge collected from a treatment facility were observed to range from 12.51 to 15.79 mg L−1 (relative standard deviation (RSD) 8.1%) and 17.56 to 18.67 mg L−1 (RSD 3.4%) respectively. The performance of this method was validated by repeatedly measuring a mid-level standard (n = 8; 10 mg L−1), with an observed RSD of 4.6%.

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Workplace bullying erodes job and personal resources: between- and within-person perspectives

Journal of Occupational Health Psychology, Aug 25 , 2014;
DOI10.1037/a0037728

Workplace bullying is a serious psychosocial occupational hazard. Despite a wealth of empirical study, research has rarely examined the mechanisms through which bullying has its negative effects. Accordingly, using both between- and within-person approaches, we investigated the erosion of job (Study 1) and personal (Study 2) resources following workplace bullying, mediated by the depletion of emotional energy. In Study 1, self-report survey data were collected from 221 retail workers at 2 time-points spaced 6 months apart. Structural equation modeling revealed that over time bullying depletes coworker support, partially mediated by emotional exhaustion. In Study 2, a 6-week diary was completed by a separate sample of 45 workers employed in various occupations. Within-person weekly variability in bullying exposure was 34%. Hierarchical linear modeling showed that weekly emotional exhaustion partially mediated the negative effects of weekly workplace bullying on both optimism and self-efficacy. The consistent pattern across both studies supports the idea of a resource loss process whereby exposure to bullying at work erodes job and personal resources by depleting energy. Future research should clarify the role of exhaustion in utilizing resources to respond to bullying, focus on predictors of within-person variability in bullying exposure, and more explicitly model the resource loss spiral following workplace bullying.

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Syphilis reaches highest levels recorded in Australia

The Guardian AAP 18 September 2014

Syphilis has reached its highest level recorded in Australia, with the increase almost exclusively among gay men.
Health experts are calling for an increased focus on the potentially deadly bacterial disease after data showed 1,765 people were diagnosed with it in Australia last year – a 34% increase on the number documented in 2009.
The annual surveillance report on the country’s sexual health produced by the Kirby Institute at the University of New South Wales said unprotected sex between men was the main driver of new diagnoses between 2009 and 2013.

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Link to 2104 Surveillance Report

Ruby Chen inquest: Conflicting evidence given about fluid three-year-old girl received during helicopter treatment

ABC News Marlina Whop and Paul Robinson 17 September 2014

Conflicting evidence has been given at a coronial inquest about fluid given to a three-year-old girl leading up to her death.
Ruby Chen went into cardiac arrest while being flown by helicopter from Blackwater Hospital to Rockhampton in August 2012.
She had suffered from a fever and dehydration days before the emergency flight.
An autopsy later determined she had died of an air embolism, which occurs when an air bubble enters a vein and blocks it.

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Shaken baby expert faces ‘witch hunt’

The Telegraph Sngela Levin, Laura Donnelly 14 September 2014

A leading doctor who acted as an expert witness for parents accused of killing their children faces being struck off, amid claims that she is the victim of a police witch hunt.

Dr Waney Squier, a paediatric neuropathologist, is due to appear before the General Medical Council (GMC) tomorrow accused of “bias” and “dishonesty” after disputing the existence of “shaken baby syndrome” in a number of court cases.

Read more:  http://www.telegraph.co.uk/health/healthnews/11094379/Shaken-baby-expert-faces-witch-hunt.html