3,837 research outputs found

    Practical application of synthetic head models in real ballistic cases.

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    In shooting crimes, ballistics tests are often recommended in order to reproduce the wound characteristics of the involved persons. For this purpose, several "simulants" can be used. However, despite the efforts in the research of "surrogates" in the field of forensic ballistic, the development of synthetic models needs still to be improved through a validation process based on specific real caseworks. This study has been triggered by the findings observed during the autopsy performed on two victims killed in the same shooting incident, with similar wounding characteristics; namely two retained head shots with ricochet against the interior wall of the skull; both projectiles have been recovered during the autopsies after migration in the brain parenchyma. The thickness of the different tissues and structures along the bullets trajectories as well as the incident angles between the bullets paths and the skull walls have been measured and reproduced during the assemblage of the synthetic head models. Two different types of models ("open shape" and "spherical") have been assembled using leather, polyurethane and gelatine to simulate respectively skin, bone and soft tissues. Six shots have been performed in total. The results of the models have been compared to the findings of post-mortem computed tomography (PMCT) and the autopsy findings.Out of the six shots, two perforated the models and four were retained. When the projectile was retained, the use of both models allowed reproducing the wounds characteristics observed on both victims in terms of penetration and ricochet behaviour. However, the projectiles recovered from the models showed less deformation than the bullets collected during the autopsies. The "open shape" model allowed a better controlling on the shooting parameters than the "spherical" model. Finally, the difference in bullet deformation could be caused by the choice of the bone simulant, which might under-represent either the strength or the density of the human bone. In our opinion, it would be worth to develop a new, more representative material for ballistic which simulates the human bone

    Excitons and charged excitons in semiconductor quantum wells

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    A variational calculation of the ground-state energy of neutral excitons and of positively and negatively charged excitons (trions) confined in a single-quantum well is presented. We study the dependence of the correlation energy and of the binding energy on the well width and on the hole mass. The conditional probability distribution for positively and negatively charged excitons is obtained, providing information on the correlation and the charge distribution in the system. A comparison is made with available experimental data on trion binding energies in GaAs-, ZnSe-, and CdTe-based quantum well structures, which indicates that trions become localized with decreasing quantum well width.Comment: 9 pages, 11 figure

    Compartmental pharmacokinetics of nefopam during mild hypothermia

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    Background Nefopam is a non-opioid, non-steroidal, centrally acting analgesic which has an opioid-sparing effect. It also reduces the threshold (triggering core temperature) for shivering without causing sedation or respiratory depression. The drug is therefore useful as both an analgesic and to facilitate induction of therapeutic hypothermia. However, compartmental pharmacokinetics during hypothermia are lacking for nefopam. Methods We conducted a prospective, randomized, blinded study in eight volunteers. On two different occasions, one of two nefopam concentrations was administered and more than 30 arterial blood samples were gathered during 12 h. Plasma concentrations were determined using gas chromatography/mass spectrometry to investigate the pharmacokinetics of nefopam with non-linear mixed-effect modelling. Results A two-compartment mammillary model with moderate inter-individual variability and inter-occasional variability independent of covariates was found to best describe the data [mean (se): V1=24.13 (2.8) litre; V2=183.34 (13.5) litre; Clel=0.54 (0.07) litre min−1; Cldist=2.84 (0.42) litre min−1]. Conclusions The compartmental data set describing a two-compartment model was determined and could be implemented to drive automated pumps. Thus, work load could be distributed to a pump establishing and maintaining any desired plasma concentration deemed necessary for a treatment with therapeutical hypothermi

    UAV-derived photogrammetric point clouds and multispectral indices for fuel estimation in Mediterranean forests

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    Sensors attached to unmanned aerial vehicles (UAVs) allow estimating a large number of forest attributes related to forest fuels. This study assesses photogrammetric point clouds and multispectral indices obtained from a fixed-wing UAV for the classification of Prometheus fuel types in 82 forest plots in AragĂłn (NE Spain). Images captured by an RGB camera and a multispectral sensor allowed generating high density photogrammetric point clouds (RGB: 3000 points/m2; multispectral: 85 points/m2), which were normalized using alternatively a Digital Elevation Model (DEM) of 0.5, 1, and 2 m resolution. A set of structural and textural variables were derived from the normalized point cloud heights, and for the latter, the gray-level co-occurrence matrix (GLCM) approach was used. Multispectral images were also used to create seven spectral vegetation indices. The most relevant structural, textural, and spectral variables to introduce into the fuel types classification models were selected using Dunn's test, which included: the vegetation height at the 50th percentile, the coefficient of variation of the heights, the percentage of returns above 4 m, the mean textural dissimilarity, and the mean of the Green Chlorophyll Index. Three different data samples were introduced in the models: i) the relevant structural and textural variables from the RGB camera (RGB data sample); ii) the relevant structural, textural, and spectral variables from the multispectral sensor (MS data sample); and iii) the relevant structural and textural variables from the RGB camera plus the relevant spectral variable from the multispectral sensor (integrated data sample). After comparing three machine learning classification techniques (Random Forest, and Linear and Radial Support Vector Machine), the best results were obtained with Random Forest with k-fold cross-validation (k-10) and the integrated data sample with normalized point clouds at 0.5 m DEM resolution (overall accuracy = 71%). The variables successfully identified the Prometheus main fire carriers (i.e., shrubs or trees) and confusions were mainly located within the fuel types of the same dominant stratum, especially in fuel types 3 and 6. These results demonstrate the ability of UAV imagery to classify forest fuels in Mediterranean environments when RGB and multispectral data are combined

    Magpie: towards a semantic web browser

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    Web browsing involves two tasks: finding the right web page and then making sense of its content. So far, research has focused on supporting the task of finding web resources through ‘standard’ information retrieval mechanisms, or semantics-enhanced search. Much less attention has been paid to the second problem. In this paper we describe Magpie, a tool which supports the interpretation of web pages. Magpie offers complementary knowledge sources, which a reader can call upon to quickly gain access to any background knowledge relevant to a web resource. Magpie automatically associates an ontologybased semantic layer to web resources, allowing relevant services to be invoked within a standard web browser. Hence, Magpie may be seen as a step towards a semantic web browser. The functionality of Magpie is illustrated using examples of how it has been integrated with our lab’s web resources

    Magnetic field dependence of the energy of negatively charged excitons in semiconductor quantum wells

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    A variational calculation of the spin-singlet and spin-triplet state of a negatively charged exciton (trion) confined to a single quantum well and in the presence of a perpendicular magnetic field is presented. We calculated the probability density and the pair correlation function of the singlet and triplet trion states. The dependence of the energy levels and of the binding energy on the well width and on the magnetic field strength was investigated. We compared our results with the available experimental data on GaAs/AlGaAs quantum wells and find that in the low magnetic field region (B<18 T) the observed transition are those of the singlet and the dark triplet trion (with angular momentum Lz=−1L_z=-1), while for high magnetic fields (B>25 T) the dark trion becomes optically inactive and possibly a transition to a bright triplet trion (angular momentum Lz=0L_z=0) state is observed.Comment: 9 pages, 10 figures submitted to Phys. Rev.

    Occupational risks in midwifery. From Bernardino Ramazzini to modern times

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    Occupational risks are often underestimated in midwifery. It is not commonly known that they were originally described by the Italian physician Bernardino Ramazzini (1633-1714) at the beginning of the eighteenth century. Our aim was to describe occupational risks in midwifery from Ramazzini to modern times. The original text by Bernardino Ramazzini was analyzed. A review of modern scientific papers on occupational risks in midwifery was conducted. Ramazzini identified two major occupational risks in midwifery: infections and awkward postures. Modern literature seems to agree with his considerations, focusing on infection, use of universal protection and personal protective equipment, and musculoskeletal problems. Modern studies also evidenced Post-Traumatic Stress Disorder that was probably postulated by Ramazzini himself. The poor number of papers in literature on midwives’ occupational risks evidences a lack of interest towards this issue. Prevention should therefore be emphasized in this field, so high-quality studies on occupational risks in midwifery are neede

    Integrated hybrid multi-regional input-output for assessing life cycle air emissions of the Italian power system

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    The air emissions of the Italian power system, as well as national emissions between 2010 and 2017 and projections to 2040, have been assessed from a lifecycle perspective, using an integrated hybrid two-region input-output model of Italy versus the rest of the world. The Italian economy is divided into 42 sectors, including electricity, which is further disaggregated into seven technologies. Detailed electricity sector data, from Istat, are fed into the EXIOBASE input-output database. NAMEA tables represent overall air emissions, while the Ecoinvent database is used for the electricity sector. Electricity transition scenarios from Terna and Snam have been integrated into input-output and air emission databases. Demand and emissions were tracked within the electricity sector over medium-term, and the findings showed a sharp decrease between 2017 and 2025, from 97.5 MtCO2 to 32.6 MtCO2. By 2040, air emissions from the electricity sector are expected to grow gradually, compared to those of 2030, from 22.2 MtCO2 to 25.9 MtCO2, suggesting that the demand between 2030 and 2040 grows faster than the decarbonization effort during the same period. There is an overall, gradual downtrend between 2010 and 2040, with all air emission categories declining by half from both production and consumption-based perspectives in this period

    Differential allelic expression of SOS1 and hyperexpression of the activating SOS1 c.755C variant in a Noonan syndrome family

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    Noonan syndrome (NS) is a genetic condition characterized by congenital heart defects, short stature and characteristic facial features. We here present the case of a girl with moderate learning disabilities, delayed language development, craniofacial features and skin anomalies reminiscent of NS. After a mutation screening of the known NS genes PTPN11, SOS1, RAF1, KRAS, GRB2, BRAF and SHOC2 we found the heterozygous c.755T>C variant in SOS1 causing the p.I252T amino-acid substitution, which was considered possibly pathogenetic by bioinformatic predictions. The same variant was present in the proband's mother, displaying some NS features, and mateRNAl grandfather showing no NS traits, but also by a healthy subject in 1000 genomes project database without phenotype informations. The functional analysis revealed that SOS1 c.755C activated the RAS-ERK intracellular pathway, whereas no effects on RAC-JNK cascade have been detected. After a comparison between the sequence of SOS1 cDNA from peripheral blood and SOS1 genomic DNA, we showed for the first time a differential allelic expression of the SOS1 gene in healthy individuals, thus occurring as a physiologic condition. Interestingly, we found that the mutated allele C was 50% more expressed than the wild-type allele T in all familial carriers. The comparable amount of SOS1 mRNA between mutated individuals and the controls indicates that the variant does not affect SOS1 expression. The present study provides a first evidence of allelic imbalance of SOS1 and pinpoints this condition as a possible mechanism underlying a different penetrance of some SOS1-mutated alleles in unrelated carriers
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