1,487 research outputs found

    Organic gunshot residues: observations about sampling and transfer mechanisms

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    This work aimed at studying the sampling, storage, transfer and persistence of organic gunshot residue (OGSR), mainly stabilizers, using liquid chromatography hyphenated to mass spectrometry. Collection using swabs and stubs was compared through sequential sampling in terms of amount of residues left on the hand of a shooter. While stubs collected nearly all residues, swabs left about 50% of the residues on the hands. Moreover, the study of storage conditions after sampling showed that stubs were more stable than swabs and could be held at room temperature without significant compound loss up to two weeks. Then, shooting experiments were performed to evaluate transfer of OGSR. It was not possible to differentiate different brands of ammunition based on a single compound concentration. Moreover, a memory effect was identified when different ammunition was shot using the same firearm. Finally, various exposed skin surfaces and hair as well as clothing were sampled to estimate what surfaces might be the best targets for OGSR sampling by comparing results just after discharge and two hours after discharging a pistol. The results indicated that OGSR were more rapidly lost from hands than from clothing. Moreover, it was shown that the face and hair of a suspect might be contaminated through secondary transfer. Thus, OGSR might remain longer on other skin surfaces, hair and clothing than on the hands of a suspect. As a consequence, sampling should also include clothing, hair and face

    Effect of insulin-like growth factor I on HIV type 1 long terminal repeat-driven chloramphenicol acetyltransferase expression

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    In this study, we have investigated the ability of insulin-like growth factor I (IGF-I) to inhibit HIV long terminal repeat (LTR)-driven gene expression. Using COS 7 cells cotransfected with tat and an HIV LTR linked to a chloramphenicol acetyltransferase (CAT) reporter, we observed that physiological levels of IGF-I (10-9 M) significantly inhibited CAT expression in a concentration- and time-dependent manner. IGF-I did not inhibit C AT expression in COS 7 cells transfected with pSVCAT, and did not affect CAT expression in the absence of cotransfection with tat . Transfection of HIV-1 proviral DNA into COS 7 cells +/- IGF-I resulted in a significant decrease ( p 0.05) in infectious virion production. Both IGF-I and Ro24-7429 inhibited LTR-driven C AT expression, while TNF- alpha -enhanced CAT expression was not affected by IGF-I. On the other hand, a plasmid encoding parathyroid hormone-related peptide exhibited dramatic additivity of inhibition of CAT expression in COS 7 cells. Finally, we show that in Jurkat or U937 cells cotransfected with HIVLTRCAT/tat, IGF-I significantly inhibited CAT expression. Further, interleukin 4 showed in U937 cells inhibition of CAT expression that was not additive to IGF-I induced inhibition. Our data demonstrate that IGF-I can specifically inhibit HIVLTRCAT expression. This inhibition may occur at the level of the tat /TAR interaction. Finally, this IGF-I effect is seen in target cell lines and similar paths of inhibition may be involved in the various cell types employed. <br /

    In vitro efficacy of tavaborole topical solution, 5% after penetration through nail polish on ex vivo human fingernails

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    This document is the Accepted Manuscript of the following article: Aditya K. Gupta, et al, 'In vitro efficacy of tavaborole topical solution, 5% after penetration through nail polish on ex vivo human fingernails', Journal of Dermatological Treatment, Jan 2018. Under embargo until 10 January 2019. The final, published version is available online at doi: https://doi.org/10.1080/09546634.2017.1422078.Background: Topical antifungal treatments for onychomycosis are applied to clean, unpolished nails for 48 weeks or longer. Patients often wish to mask their infection with nail polish yet there is no evidence to suggest antifungal efficacy in the presence of nail polish. Objective: To determine if tavaborole retains the ability to penetrate the nail plate and inhibit fungal growth in the presence of nail polish. Method: Tavaborole was applied to human fingernails painted with 2 or 4 coats of nail polish, and unpainted nails in an ex vivo model. Nails were mounted on TurChub Âź chambers seeded with Trichophyton rubrum and allowed to incubate for 7 days. Antifungal activity was assessed by measuring zones of inhibition. Results and conclusion: Tavaborole exhibited antifungal activity in all experimental groups. The zones of inhibition of T. rubrum for all experimental groups (2 or 4 coats of polish, unpolished) were greater than infected controls (polished and unpolished), p s <.001. Tavaborole penetrates polished nails and kills T. rubrum in this ex vivo model.Peer reviewe

    Measuring vertebrate telomeres: applications and limitations

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    Telomeres are short tandem repeated sequences of DNA found at the ends of eukaryotic chromosomes that function in stabilizing chromosomal end integrity. In vivo studies of somatic tissue of mammals and birds have shown a correlation between telomere length and organismal age within species, and correlations between telomere shortening rate and lifespan among species. This result presents the tantalizing possibility that telomere length could be used to provide much needed information on age, ageing and survival in natural populations where longitudinal studies are lacking. Here we review methods available for measuring telomere length and discuss the potential uses and limitations of telomeres as age and ageing estimators in the fields of vertebrate ecology, evolution and conservation

    Psychopathy and aggression: Examining the role of psychopathy factors in predicting laboratory aggression under hostile and instrumental conditions

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    Abstract Psychopathy is a problematic configuration of traits and behaviors that is consistently correlated with aggressive, criminal behavior. Studies have suggested that psychopathy is composed of related but distinct factors that manifest divergent relations with a host of constructs including aggression. In the current study, we used a sample of 126 men to examine whether these psychopathy factors are differentially related to aggression manifested in two conditions (instrumental and hostile/reactive aggression) of a laboratory aggression paradigm. Traits related to an antagonistic interpersonal style and emotional detachment (i.e., Factor 1) were related to aggression in both conditions whereas traits related to negative emotionality, impulsivity, and an antagonistic style (i.e., Factor 2) were related to aggression only in the hostile/reactive condition. Potential explanations for these findings are put forth

    Transforming teacher education, an activity theory analysis

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    This paper explores the work of teacher education in England and Scotland. It seeks to locate this work within conflicting socio-cultural views of professional practice and academic work. Drawing on an activity theory framework that integrates the analysis of these contradictory discourses with a study of teacher educators’ practical activities, including the material artefacts that mediate the work, the paper offers a critical perspective on the social organisation of university-based teacher education. Informed by Engeström’s activity theory concept of transformation, the paper extends the discussion of contradictions in teacher education to consider the wider socio-cultural relations of the work. The findings raise important questions about the way in which teacher education work within universities is organised and the division of labour between schools and universities
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