Probabilistic evidential assessment of gunshot residue particle evidence (Part I): likelihood ratio calculation and case pre-assessment using Bayesian networks

Well developed experimental procedures currently exist for retrieving and analyzing particle evidence from hands of individuals suspected of being associated with the discharge of a firearm. Although analytical approaches (e.g. automated Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDS) microanalysis) allow the determination of the presence of elements typically found in gunshot residue (GSR) particles, such analyses provide no information about a given particle's actual source. Possible origins for which scientists may need to account for are a primary exposure to the discharge of a firearm or a secondary transfer due to a contaminated environment. In order to approach such sources of uncertainty in the context of evidential assessment, this paper studies the construction and practical implementation of graphical probability models (i.e. Bayesian networks). These can assist forensic scientists in making the issue tractable within a probabilistic perspective. The proposed models focus on likelihood ratio calculations at various levels of detail as well as case pre-assessment.

A genome-wide screen for interactions reveals a new locus on 4p15 modifying the effect of waist-to-hip ratio on total cholesterol.

Recent genome-wide association (GWA) studies described 95 loci controlling serum lipid levels. These common variants explain ∼25% of the heritability of the phenotypes. To date, no unbiased screen for gene-environment interactions for circulating lipids has been reported. We screened for variants that modify the relationship between known epidemiological risk factors and circulating lipid levels in a meta-analysis of genome-wide association (GWA) data from 18 population-based cohorts with European ancestry (maximum N = 32,225). We collected 8 further cohorts (N = 17,102) for replication, and rs6448771 on 4p15 demonstrated genome-wide significant interaction with waist-to-hip-ratio (WHR) on total cholesterol (TC) with a combined P-value of 4.79×10(-9). There were two potential candidate genes in the region, PCDH7 and CCKAR, with differential expression levels for rs6448771 genotypes in adipose tissue. The effect of WHR on TC was strongest for individuals carrying two copies of G allele, for whom a one standard deviation (sd) difference in WHR corresponds to 0.19 sd difference in TC concentration, while for A allele homozygous the difference was 0.12 sd. Our findings may open up possibilities for targeted intervention strategies for people characterized by specific genomic profiles. However, more refined measures of both body-fat distribution and metabolic measures are needed to understand how their joint dynamics are modified by the newly found locus.

Molar substitution and C2/C6 ratio of hydroxyethyl starch: influence of blood coagulation

Résumé Cette étude a démontré l'effet individuel sur la coagulation sanguine humaine des deux principales caractéristiques de la molécule d'hydroxyéthylamidon (HES) : la substitution molaire et le rapport C2/C6. L'analyse par thrombélastographe (TEG®) indique que la molécule de HES dont la substitution molaire est de 0.42 et le rapport C2/C6 de 2.7 a le moins d'effet sur la coagulation sanguine chez l'être humain. Objectifs de l'étude Le développement d'hydroxyéthylamidons (HES) qui ont à la fois peu d'impact sur la coagulation sanguine et une longue persistance intravasculaire est d'un grand intérêt clinique. Une précédente étude in vitro a démontré qu'une solution de HES de haut poids moléculaire et de bas degré de substitution molaire ne compromettait pas plus la coagulation sanguine qu'une solution HES de poids moléculaire moyen (1). La présente étude examine l'effet individuel de la substitution molaire et du rapport C2/C6 d'une solution de HES de haut poids moléculaire (700 kDa) sur la coagulation sanguine. Matériel et méthode Nous avons prélevé du sang chez 30 adultes en bonne santé; le sang a été mélangé avec 6 solutions de HES qui diffèrent par leur degré de substitution molaire (0.42 et 0.51) et leur rapport C2/C6 (2.7, 7 et 14) à trois degrés de dilution : 20%, 40% et 60%. Les échantillons ont ensuite été analysés par thrombélastographe. Les données ont été étudiées par analyse de variance à trois voies pour mesures répétées sur une voie (dilution). Résultats Plus la substitution molaire est élevée, plus la coagulation sanguine est compromise et ce concernant tous les paramètres du TEG® (tous les p sont < à 0.05). La solution HES avec le rapport C2/C6 le plus bas a l'effet le moins prononcé sur le temps r (p<0.001), l'angle α (p=0.003) et l'Index de Coagulation CI (p<0.001) ; on n'a pas observé d'effet sur le temps k (p=0.513) et l'amplitude maximale (p=0.699) concernant ce paramètre. Conclusion L'analyse par thrombélastographe révèle qu'une molécule de HES avec une substitution molaire de 0.42 et un rapport C2/C6 de 2.7 a un effet minimal sur la coagulation sanguine humaine in vitro.

Feeding strategies and energy to protein ratio on tambaqui performance and physiology

The objective of this work was to evaluate the effect of feed deprivation and refeeding with diets containing different energy to protein ratios (E/P) on the performance and physiology of juvenile tambaqui (Colossoma macropomum). A 4x2 factorial arrangement with three replicates was used, with four E/P ratios (11.5, 10.5, 9.5, and 8.5 kcal g-1 digestible energy per protein) and two feeding regimens (with and without deprivation), during 60 days. Fish from the food-deprived group were fasted for 14 days and refed from the fifteenth to the sixtieth day, whereas the remaining fish were fed for 60 days. At the end of the experimental period, weight of fish subjected to food deprivation was lower than that of those continuously fed; however, this condition did not influence the physiological parameters analyzed. Tambaqui fed 11.5 kcal g-1 achieved lower final weight than those fed with the other diets, in both regimens. Among the physiological parameters, only plasma protein presented significant increase in fish fed 8.5 kcal g-1, in both feeding regimens, probably due to the higher dietary protein concentration. These results indicate that fish show a partial compensatory growth, and that 10.5 kcal g-1 can be recommended for the diet of juvenile tambaqui.

Toward Synchronous Extensible Dependency Grammar

Extensible Dependency Grammar (XDG; Debusmann, 2007) is a flexible, modular dependency grammarframework in which sentence analyses consist of multigraphs and processing takes the form of constraint satisfaction. This paper shows how XDGlends itself to grammar-driven machine translation and introduces the machinery necessary for synchronous XDG. Since the approach relies on a shared semantics, it resembles interlingua MT.It differs in that there are no separateanalysis and generation phases. Rather, translation consists of the simultaneousanalysis and generation of a single source-target sentence.

Maternal exposure to polychlorinated biphenyls and the secondary sex ratio: an occupational cohort study.

Background: Though commercial production of polychlorinated biphenyls was banned in the United States in 1977, exposure continues due to their environmental persistence. Several studies have examined the associationbetween environmental polychlorinated biphenyl exposure and modulations of the secondary sex ratio, with conflicting results.Objective: Our objective was to evaluate the association between maternal preconceptional occupational polychlorinated biphenyl exposure and the secondary sex ratio.Methods: We examined primipara singleton births of 2595 women, who worked in three capacitor plants at least one year during the period polychlorinated biphenyls were used. Cumulative estimated maternal occupationalpolychlorinated biphenyl exposure at the time of the infant's conception was calculated from plant-specific job exposure matrices. A logistic regression analysis was used to evaluate the association between maternalpolychlorinated biphenyl exposure and male sex at birth (yes/no).Results: Maternal body mass index at age 20, smoking status, and race did not vary between those occupationally exposed and those unexposed before the child's conception. Polychlorinated biphenyl-exposed mothers were, however, more likely to have used oral contraceptives and to have been older at the birth of their first child than non-occupationally exposed women. Among 1506 infants liveborn to polychlorinated biphenyl-exposedprimiparous women, 49.8% were male; compared to 49.9% among those not exposed (n = 1089). Multivariate analyses controlling for mother's age and year of birth found no significant association between the odds of amale birth and mother's cumulative estimated polychlorinated biphenyl exposure to time of conception.Conclusions: Based on these data, we find no evidence of altered sex ratio among children born to primiparous polychlorinated biphenyl-exposed female workers.

Inbreeding and selection on sex ratio in the bark beetle Xylosandrus germanus.

ABSTRACT: BACKGROUND: Local Mate Competition (LMC) theory predicts a female should produce a more female-biased sex ratio if her sons compete with each other for mates. Because it provides quantitative predictions that can be experimentally tested, LMC is a textbook example of the predictive power of evolutionary theory. A limitation of many earlier studies in the field is that the population structure and mating system of the studied species are often estimated only indirectly. Here we use microsatellites to characterize the levels of inbreeding of the bark beetle Xylosandrus germanus, a species where the level of LMC is expected to be high. RESULTS: For three populations studied, genetic variation for our genetic markers was very low, indicative of an extremely high level of inbreeding (FIS = 0.88). There was also strong linkage disequilibrium between microsatellite loci and a very strong genetic differentiation between populations. The data suggest that matings among non-siblings are very rare (3%), although sex ratios from X. germanus in both the field and the laboratory have suggested more matings between non-sibs, and so less intense LMC. CONCLUSIONS: Our results confirm that caution is needed when inferring mating systems from sex ratio data, especially when a lack of biological detail means the use of overly simple forms of the model of interest.

Evaluation de la qualité des sites internet francophones traitant de la dépendance à l'alcool [Assessing the quality of French language web sites pertaining to alcohol dependency]

The objective of this article is to systematically assess the quality of web-based information in French language on the alcohol dependence. The authors analysed, using a standardised pro forma, the 20 most highly ranked pages identified by 3 common internet search engines using 2 keywords. Results show that a total of 45 sites were analysed. The authors conclude that the overall quality of the sites was relatively poor, especially for the description of possible treatments, however with a wide variability. Content quality was not correlated with other aspects of quality such as interactivity, aesthetic or accountability.

Sex ratio and Wolbachia infection in the ant Formica exsecta.

Sex allocation data in social Hymenoptera provide some of the best tests of kin selection, parent-offspring conflict and sex ratio theories. However, these studies critically depend on controlling for confounding ecological factors and on identifying all parties that potentially manipulate colony sex ratio. It has been suggested that maternally inherited parasites may influence sex allocation in social Hymenoptera. If the parasites can influence sex allocation, infected colonies are predicted to invest more resources in females than non-infected colonies, because the parasites are transmitted through females but not males. Prime candidates for such sex ratio manipulation are Wolbachia, because these cytoplasmically transmitted bacteria have been shown to affect the sex ratio of host arthropods by cytoplasmic incompatibility, parthenogenesis, male-killing and feminization. In this study, we tested whether Wolbachia infection is associated with colony sex ratio in two populations of the ant Formica exsecta that have been the subject of extensive sex ratio studies. In these populations colonies specialize in the production of one sex or the other. We found that almost all F. exsecta colonies in both populations are infected with Wolbachia. However, in neither population did we find a significant association in the predicted direction between the prevalence of Wolbachia and colony sex ratio. In particular, colonies with a higher proportion of infected workers did not produce more females. Hence, we conclude that Wolbachia does not seem to alter the sex ratio of its hosts as a means to increase transmission rate in these two populations of ants.

Contribution of isotope ratio mass spectrometry to the investigation of improvised explosives: isotopic study of black powders ans ammonium nitrates

The establishment of legislative rules about explosives in the eighties has reduced the illicit use of military and civilian explosives. However, bomb-makers have rapidly taken advantage of substances easily accessible and intended for licit uses to produce their own explosives. This change in strategy has given rise to an increase of improvised explosive charges, which is moreover assisted by the ease of implementation of the recipes, widely available through open sources. While the nature of the explosive charges has evolved, instrumental methods currently used in routine, although more sensitive than before, have a limited power of discrimination and allow mostly the determination of the chemical nature of the substance. Isotope ratio mass spectrometry (IRMS) has been applied to a wide range of forensic materials. Conclusions drawn from the majority of the studies stress its high power of discrimination. Preliminary studies conducted so far on the isotopic analysis of intact explosives (pre-blast) have shown that samples with the same chemical composition and coming from different sources could be differentiated. The measurement of stable isotope ratios appears therefore as a new and remarkable analytical tool for the discrimination or the identification of a substance with a definite source. However, much research is still needed to assess the validity of the results in order to use them either in an operational prospect or in court. Through the isotopic study of black powders and ammonium nitrates, this research aims at evaluating the contribution of isotope ratio mass spectrometry to the investigation of explosives, both from a pre-blast and from a post-blast approach. More specifically, the goal of the research is to provide additional elements necessary to a valid interpretation of the results, when used in explosives investigation. This work includes a fundamental study on the variability of the isotopic profile of black powder and ammonium nitrate in both space and time. On one hand, the inter-variability between manufacturers and, particularly, the intra-variability within a manufacturer has been studied. On the other hand, the stability of the isotopic profile over time has been evaluated through the aging of these substances exposed to different environmental conditions. The second part of this project considers the applicability of this high-precision technology to traces and residues of explosives, taking account of the characteristics specific to the field, including their sampling, a probable isotopic fractionation during the explosion, and the interferences with the matrix of the site.

Independent sources of condition dependency and multiple pathways determine a composite trait: lessons from carotenoid-based plumage colouration.

Many colour ornaments are composite traits consisting of at least four components, which themselves may be more complex, determined by independent evolutionary pathways, and potentially being under different environmental control. To date, little evidence exists that several different components of colour elaboration are condition dependent and no direct evidence exists that different ornamental components are affected by different sources of variation. For example, in carotenoid-based plumage colouration, one of the best-known condition-dependent ornaments, colour elaboration stems from both condition-dependent pigment concentration and structural components. Some environmental flexibility of these components has been suggested, but specifically which and how they are affected remains unknown. Here, we tested whether multiple colour components may be condition dependent, by using a comprehensive 3 × 2 experimental design, in which we carotenoid supplemented and immune challenged great tit nestlings (Parus major) and quantified effects on different components of colouration. Plumage colouration was affected by an interaction between carotenoid availability and immune challenge. Path analyses showed that carotenoid supplementation increased plumage saturation via feather carotenoid concentration and via mechanisms unrelated to carotenoid deposition, while immune challenge affected feather length, but not carotenoid concentration. Thus, independent condition-dependent pathways, affected by different sources of variation, determine colour elaboration. This provides opportunities for the evolution of multiple signals within components of ornamental traits. This finding indicates that the selective forces shaping the evolution of different components of a composite trait and the trait's signal content may be more complex than believed so far, and that holistic approaches are required for drawing comprehensive evolutionary conclusions.

Information sharing in R&D collaboration - Context-dependency and means of governance

Tiedon jakaminen ja kommunikointi ovat tärkeitä toimintoja verkostoituneiden yritysten välillä ja ne käsitetäänkin yhteistyösuhteen yhtenä menestystekijänä ja kulmakivenä. Tiedon jakamiseen liittyviä haasteita ovat mm. yrityksen liiketoiminnalle kriittisen tiedon vuotaminen ja liiketoiminnan vaatima tiedon reaaliaikaisuus ja riittävä määrä. Tuotekehitysyhteistyössä haasteellista on tiedon jäsentymättömyys ja sitä kautta lisääntyvä tiedon jakamisen tarve, minkä lisäksi jaettava tieto on usein monimutkaista ja yksityiskohtaista. Lisäksi tuotteiden elinkaaret lyhenevät, ja ulkoistaminen ja yhteistyö ovat yhä kasvavia trendejä liiketoiminnassa. Yhdessä nämä tekijät johtavat siihen, että tiedon jakaminen on haastavaa eritoten verkostoituneiden yritysten välillä. Tässä tutkimuksessa tiedon jakamisen haasteisiin pyrittiin vastaamaan ottamalla lähtökohdaksi tiedon jakamisen tilanneriippuvuuden ymmärtäminen. Työssä vastattiin kahteen pääkysymykseen: Mikä on tiedon jakamisen tilanneriippuvuus ja miten sitä voidaan hallita? Tilanneriippuvuudella tarkoitetaan työssä niitä tekijöitä, jotka vaikuttavat siihen, miten yritys jakaa tietoa tuotekehityskumppaneidensa kanssa. Tiedon jakamisella puolestaan tarkoitetaan yrityksestä toiselle siirrettävää tietoa, jota tarvitaan tuotekehitysprojektin aikana. Työn empiirinen aineisto on kerätty laadullisella tutkimusotteella case- eli tapaustutkimuksena yhdessä telekommunikaatioalan yrityksessä jasen eri liiketoimintayksiköissä. Tutkimusjoukko käsitti 19 tuotekehitys- ja toimittajanhallintatehtävissä toimivaa johtajaa tai päällikköä. Työ nojaa pääasiassa hankintojen johtamisen tutkimuskenttään ja tilanneriippuvuuden selvittämiseksi paneuduttiin erityisesti verkostojen tutkimukseen. Työssä kuvattiin tiedon jakaminen yhtenä verkoston toimintona ja yhteistyöhön liittyvättiedon jakamisen hyödyt, haasteet ja riskit identifioitiin. Tämän lisäksi työssä kehitettiin verkoston tutkimismalleja ja yhdistettiin eri tasoilla tapahtuvaa verkoston tutkimusta. Työssä esitettiin malli verkoston toimintojen tutkimiseksija todettiin, että verkostotutkimusta pitäisi tehdä verkosto, ketju, yrityssuhde- ja yritystasolla. Malliin on myös hyvä yhdistää tuote- ja tehtäväkohtaiset ominaispiirteet. Kirjallisuuskatsauksen perusteella huomattiin, että tiedon jakamista on aiemmin tarkasteltu lähinnä tuote- ja yrityssuhteiden tasolla. Väitöskirjassa esitettiin lisää merkittäviä tekijöitä, jotka vaikuttavat tiedon jakamiseen. Näitä olivat mm. tuotekehitystehtävän luonne, teknologia-alueen kypsyys ja toimittajan kyvykkyys. Tiedon jakamisen luonnetta tarkasteltaessa erotettiin operatiivinen, projektin hallintaan ja tuotekehitykseen liittyvä tieto sekä yleinen, toimittajan hallintaan liittyvä strateginen tieto. Tulosten mukaan erityisesti tuotekehityksen määrittelyvaihe ja tapaamiset kasvotusten korostuivat yhteistyössä. Empirian avulla tutkittiin myös niitä tekijöitä, joilla tiedon jakamista voidaan hallita tilanneriippuvuuteen perustuen, koska aiemmin tiedon jakamisen hallintakeinoja tai menestystekijöitä ei ole liitetty suoranaisesti eri olosuhteisiin. Nämä hallintakeinot jaettiin yhteistyötason- ja tuotekehitysprojektitason tekijöihin. Yksi työn keskeisistä tuloksista on se, että huolimatta tiedon jakamisen haasteista, monet niistä voidaan eliminoida tunnistamalla vallitsevat olosuhteet ja panostamalla tiedon jakamisen hallintakeinoihin. Työn manageriaalinen hyöty koskee erityisesti yrityksiä, jotka suunnittelevat ja tekevät tuotekehitysyhteistyötä yrityskumppaniensa kanssa. Työssä esitellään keinoja tämän haasteellisen tehtäväkentän hallintaan ja todetaan, että yritysten pitäisikin kiinnittää entistä enemmän huomiota tiedon jakamisen ja kommunikaation hallintaan jo tuotekehitysyhteistyötä suunniteltaessa.

Isotope ratio mass spectrometry as a tool for source inference in forensic science: a critical review

Isotope ratio mass spectrometry (IRMS) has been used in numerous fields of forensic science in a source inference perspective. This review compiles the studies published on the application of isotope ratio mass spectrometry (IRMS) to the traditional fields of forensic science so far. It completes the review of Benson et al. [1] and synthesises the extent of knowledge already gathered in the following fields: illicit drugs, flammable liquids, human provenancing, microtraces, explosives and other specific materials (packaging tapes, safety matches, plastics, etc.). For each field, a discussion assesses the state of science and highlights the relevance of the information in a forensic context. Through the different discussions which mark out the review, the potential and limitations of IRMS, as well as the needs and challenges of future studies are emphasized. The paper elicits the various dimensions of the source which can be obtained from the isotope information and demonstrates the transversal nature of IRMS as a tool for source inference.

Sex differences in brain plasticity: a new hypothesis for sex ratio bias in autism.

Several observations support the hypothesis that differences in synaptic and regional cerebral plasticity between the sexes account for the high ratio of males to females in autism. First, males are more susceptible than females to perturbations in genes involved in synaptic plasticity. Second, sex-related differences in non-autistic brain structure and function are observed in highly variable regions, namely, the heteromodal associative cortices, and overlap with structural particularities and enhanced activity of perceptual associative regions in autistic individuals. Finally, functional cortical reallocations following brain lesions in non-autistic adults (for example, traumatic brain injury, multiple sclerosis) are sex-dependent. Interactions between genetic sex and hormones may therefore result in higher synaptic and consecutively regional plasticity in perceptual brain areas in males than in females. The onset of autism may largely involve mutations altering synaptic plasticity that create a plastic reaction affecting the most variable and sexually dimorphic brain regions. The sex ratio bias in autism may arise because males have a lower threshold than females for the development of this plastic reaction following a genetic or environmental event.