The fate and behaviour of gunshot residue: recreational shooter distribution

Despite continued improvements in gunshot residue (GSR) detection and analysis, there are still challenges in the interpretation of GSR evidence. The level and distribution of GSR present on an individual can be influenced by many factors, dependent upon the context of any given case. Due and diligent attention must therefore be placed upon fate and behaviour processes in relation to GSR when assessing and interpreting any case findings. The distribution of GSR upon the body of a recreational shooter was assessed. Samples were taken from 17 positions across a shooter’s body immediately after the discharge of one round of ammunition. The shooting hand prevailed as the most GSR-contaminated area, with as many as 351 characteristic GSR particles identified. The face and supporting hand also exhibited high levels of GSR contamination. This level of contamination raises questions concerning the fate and behaviour of GSR particles within the general environment, specifically with regard to transfer processes

Anti-MRSA Activity of Oxysporone and Xylitol from the Endophytic Fungus Pestalotia sp. Growing on the Sundarbans Mangrove Plant Heritiera fomes

Heritiera fomes Buch.-Ham., a mangrove plant from the Sundarbans, has adapted to a unique habitat, muddy saline water, anaerobic soil, brackish tidal activities and high microbial competition. Endophytic fungal association protects this plant from adverse environmental conditions. This plant is used in Bangladeshi folk medicine, but it has not been extensively studied phytochemically, and there is hardly any report on investigation on endophytic fungi growing on this plant. In this study, endophytic fungi were isolated from the surface sterilized cladodes and leaves of H. fomes. The antimicrobial activities were evaluated against two Gram-positive and two Gram-negative bacteria and the fungal strain, Candida albicans. Extracts of Pestalotia sp. showed activities against all test bacterial strains, except that the EtOAc extract was inactive against E. coli. The structures of the purified compounds, oxysporone and xylitol, were elucidated by spectroscopic means. The anti-MRSA potential of the isolated compounds were determined against various MRSA strains, i.e., ATCC 25923, SA-1199B, RN4220, XU212, EMRSA-15 and EMRSA-16, with MIC values ranging from 32-128 g/mL. This paper, for the first time, reports on the anti-MRSA property of oxysporone and xylitol, isolation of the endophyte Pestalotia sp. from H. fomes, and isolation of xylitol from a Pestalotia sp

ASCA observations of Seyfert 1 galaxies: I. Data Analysis, Imaging and Timing

We present the first in a series of papers describing the X-ray properties of a sample of 18 Seyfert 1 galaxies, using data obtained by \asca. The imaging data reveal a number of serendipitous hard X-ray sources in some source fields, but none contribute significantly to the hard X-ray flux of the AGN. All but one of the Seyferts show evidence for variability on timescales of minutes-hours, with the amplitude anti-correlated with the source luminosity, confirming previous results. In at least 8 sources, there is evidence that the variability amplitude below 2 keV is greater than that in the hard X-ray band, perhaps indicating variable components other than the power-law in the soft band. Ultra-rapid variability, implying significant power at frequencies $> 10^{-3}$~Hz is detected in at least 5 sources, but is difficult to detect in most cases, due to the sampling and signal-to-noise ratio. In Mrk 766 and MCG-6-30-15 there is also an indication that the high--frequency power--spectra are variable in shape and/or intensity. There is similar evidence in NGC 4151, but on longer time scales.Comment: 30 pages, 5 figures. LaTeX with encapsulated postscript. To appear in the Astrophysical Journal. Also available via http://lheawww.gsfc.nasa.gov/~nandra/pubs/paper1/abstract.htm

Coronary Artery Calcium Scores: Current Thinking and Clinical Applications

Most incident coronary disease occurs in previously asymptomatic individuals who were considered to be at a lower risk by traditional screening methods. There is a definite advantage if these individuals could be reclassified into a higher risk category, thereby impacting disease outcomes favorably. Coronary artery calcium scores have been recognized as an independent marker for adverse prognosis in coronary disease. Multiple population based studies have acknowledged the shortcomings of risk prediction models such as the Framingham risk score or the Procam score. The science behind coronary calcium is discussed briefly followed by a review of current thinking on calcium scores. An attempt has been made to summarize the appropriate indications and use of calcium scores

A review of bronchiolitis obliterans syndrome and therapeutic strategies

Lung transplantation is an important treatment option for patients with advanced lung disease. Survival rates for lung transplant recipients have improved; however, the major obstacle limiting better survival is bronchiolitis obliterans syndrome (BOS). In the last decade, survival after lung retransplantation has improved for transplant recipients with BOS. This manuscript reviews BOS along with the current therapeutic strategies, including recent outcomes for lung retransplantation

Organic compositional analysis of propellant powders using monolithic material sorption extraction (MSSE)-a feasibility study

The application of monolithic material sorption extraction, specifically MonoTrapTM, to the extraction of organic gunshot residue (OGSR) compounds from unburnt propellant powders is described. Four different MonoTraps were assessed for their capability to extract OGSR compounds from two different ammunition types. Extracts were analysed using gas chromatography-mass spectrometry. Results indicated that the carbon disc was suitable for the extraction of OGSR compounds from unburnt propellant powders. Quantities for major compounds were comparable to methanol extractions. The method was successfully used to detect a wide range of OGSR compounds, including nitrotoluenes, nitroglycerin, diphenylamines and centralites and is expected to be applicable to a wide range of ammunition types

Statistical support for uncertainty in radiological diagnosis

Radiological interpretation and diagnosis involves the comparison and classification of complex medical images and is typical of the categorisation tasks that have been the subject of observational studies in Cognitive Science. This paper considers the affinity between statistical modelling and theories of categorisation for naturally occurring categories. Statistical based measures of similarity and typicality with a probabilistic interpretation are derived. The utilisation of these measures in the support of diagnosis under uncertainty via interactive overview plots is described. The application of the methodology to magnetic resonance imaging of the head is considered. The methods detailed have application to other fields involving archiving and retrieving of image data

Femtosecond time-resolved absorption spectoscopy of main-form and high-salt peridinin-chlorophyll a-proteins at low temperatures

Steady-state and femtosecond time-resolved optical methods have been used to compare the spectroscopic features and energy transfer dynamics of two systematically different light-harvesting complexes from the dinoflagellate 'Amphidinium carterae': main-form (MFPCP) and high-salt (HSPCP) peridinin-chlorophyll a-proteins. Pigment analysis and X-ray diffraction structure determinations [Hofmann, E., Wrench, P. M., Sharples, F. P., Hiller, R. G., Welte, W., Diederichs, K. (1996) Science 272, 1788-1791; T. Schulte, F. P. Sharples, R. G. Hiller, and E. Hofmann, unpublished results] have revealed the composition and geometric arrangements of the protein-bound chromophores. The MFPCP contains eight peridinins and two chlorophyll (Chl) a, whereas the HSPCP has six peridinins and two Chl a, but both have very similar pigment orientations. Analysis of the absorption spectra has shown that the peridinins and Chls absorb at different wavelengths in the two complexes. Also, in the HSPCP complex, the Qy transitions of the Chls are split into two well-resolved bands. Quantum computations by modified neglect of differential overlap with partial single and double configuration interaction (MNDO-PSDCI) methods have revealed that charged amino acid residues within 8 Å of the pigment molecules are responsible for the observed spectral shifts. Femtosecond time-resolved optical spectroscopic kinetic data from both complexes show ultrafast (<130 fs) and slower (~2 ps) pathways for energy transfer from the peridinin excited singlet states to Chl. The Chl-to-Chl energy transfer rate constant for both complexes was measured and is discussed in terms of the Förster mechanism. It was found that, upon direct Chl excitation, the Chl-to-Chl energy transfer rate constant for MFPCP was a factor of 4.2 larger than for HSPCP. It is suggested that this difference arises from a combination of factors including distance between Chls, spectral overlap, and the presence of two additional peridinins in MFPCP that act as polarizable units enhancing the rate of Chl-to-Chl energy transfer. The study has revealed specific pigment-protein interactions that control the spectroscopic features and energy transfer dynamics of these light-harvesting complexes.12 page(s