186 research outputs found
SOME FORENSIC ASPECTS OF BALLISTIC IMAGING
Analysis of ballistics evidence (spent cartridge casings and bullets) has been a staple of forensic criminal investigation for almost a century. Computer-assisted databases of images of ballistics evidence have been used since the mid-1980s to help search for potential matches between pieces of evidence. In this article, we draw on the 2008 National Research Council Report Ballistic Imaging to assess the state of ballistic imaging technology. In particular, we discuss the feasibility of creating a national reference ballistic imaging database (RBID) from test-fires of all newly manufactured or imported firearms. A national RBID might aid in using crime scene ballistic evidence to generate investigative leads to a crime gun’s point of sale. We conclude that a national RBID is not feasible at this time, primarily because existing imaging methodologies have insufficient discriminatory power. We also examine the emerging technology of micro- stamping for forensic identification purposes: etching a known identifier on firearm or ammunition parts so that they can be directly read and recovered from crime scene evidence. Microstamping could provide a stronger basis for identification based on ballistic evidence than the status quo, but substantial further research is needed to thoroughly assess its practical viability
Passive broadband full Stokes polarimeter using a Fresnel cone
Light's polarisation contains information about its source and interactions,
from distant stars to biological samples. Polarimeters can recover this
information, but reliance on birefringent or rotating optical elements limits
their wavelength range and stability. Here we present a static, single-shot
polarimeter based on a Fresnel cone - the direct spatial analogue to the
popular rotating quarter-wave plate approach. We measure the average angular
accuracy to be 2.9 (3.6) degrees for elliptical(linear) polarisation states
across the visible spectrum, with the degree of polarisation determined to
within 0.12(0.08). Our broadband full Stokes polarimeter is robust,
cost-effective, and could find applications in hyper-spectral polarimetry and
scanning microscopy.Comment: 6 Pages, 4 Figure
The effect of Cichorium intybus and Lotus corniculatus on nematode burdens and production in grazed lambs
This report was presented at the UK Organic Research 2002 Conference. The study was designed to examine the hypothesis that chicory (Cichorium intybus) and Lotus sp. (Lotus corniculatus) have the potential to affect the naturally acquired nematode burden in grazed lambs. Organic male castrate lambs (48) with a naturally acquired parasite burden grazed replicate combination plots (0.6 ha) of chicory, Lotus corniculatus, perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). Lamb performance was determined by weekly weight gain and condition score assessments. Nematode burden was assessed by individual lamb faecal egg count (FEC) before and after drenching (levamisole). The range of parasitic helminths present was assessed by faecal culture and by total worm counts performed on a proportion of the lambs at slaughter. Weekly pasture larval counts (PLCs) were conducted on the trial plots. A concurrent small plot study (6 x 1m2 replicates) of each of the forages used in the grazing trial was run to assess the potential effect of forage type on the development and survival of Teladorsagia circumcincta assessed by weekly PLCs. Preliminary data suggest that lambs grazing chicory or a combination of lotus and chicory had lower FECs than those grazing PRG/WC, however there was no significant difference in the total worm counts
The first ever anti-football painting: A consideration of the soccer match in John Singer Sargent’s "Gassed"
The paper presents a discussion of Gassed, a large oil painting by John Singer Sargent displayed at the Imperial War Museum in London. Completed in 1919, Gassed is the major achievement from Sargent’s commission as an official war artist at the appointment of the British War Memorials Committee during the latter period of World War I. Prominent in the painting is a group of soldiers, blinded by a mustard gas attack, being lead to a casualty clearing station tent. In the distant background of the painting, another group of soldiers can be seen kitted out in football attire playing a match. The significance of this football imagery is our point of enquiry. As our title suggests, some recent interpretations regard the painting as offering critical reflection, from the time, about the symbolic links between sport and war. However, while the painting may certainly be left open to this type of viewer interpretation, archival and secondary resource material research does not support such a critical intention by the artist. Yet, nor is there evidence that Sargent’s intention was the projection of war-heroism. Rather, Sargent’s endeavour to faithfully represent what he observed allows Gassed to be regarded as a visual record of routine activity behind the lines and of football as an aspect of the daily life of British soldiers during the Great War
Social Deprivation of Infant Rhesus Monkeys Alters the Chemoarchitecture of the Brain: I. Subcortical Regions
Rhesus monkeys (Macaca mulatta) reared during the first year of life without social contact develop persistent stereotyped movements, self-directed behaviors, and psychosocial abnormalities, but neurobiological mechanisms underlying the behaviors of socially deprived (SD) monkeys are unknown. Monkeys were reared in total social deprivation for the first 9 months of life; control monkeys were reared socially (SR) with mothers and peers. Subjects were killed at 19-24 yr of age. Because the behaviors of SD monkeys are reminiscent of changes in striatal or amygdalar function, we used immunocytochemistry for substance P (SP), leutine-enkephalin (LENK), somatostatin, calbindin, and tyrosine hydroxylase (TH) to evaluate qualitatively and quantitatively patterns of neurotransmitter marker immunoreactivity within subcortical regions. In SD monkeys, the chemoarchitecture of the striatum was altered. Neuronal cell bodies and processes immunoreactive for SP and LENK were depleted markedly in patch (striosome) and matrix regions of the caudate nucleus and putamen; the average density of SP-immunoreactive neurons was reduced 58% relative to SR monkeys. Calbindin and TH immunoreactivities were diminished in the matrix of caudate and putamen of SD monkeys. TH-immunoreactive neurons, but not cresyl violet-stained neurons, in the substantia nigra pars compacta were decreased (43%) in SD monkeys. Peptide-immunoreactive terminals were reduced in the globus pallidus and substantia nigra in SD monkeys. The nucleus accumbens was the least affected of striatal regions. Striatal somatostatin immunoreactivity was qualitatively and quantitatively similar in SD and SR monkeys. Several regions, for example, bed nucleus of the stria terminalis, amygdala, and basal forebrain magnocellular complex, that were in the same sections and are enriched in these markers did not appear altered in SD monkeys, suggesting a regional specificity for vulnerability. The altered chemoarchitecture of some basal ganglia regions in adult monkeys that experienced social deprivation as infants suggests that the postnatal maturation of neurotransmitter phenotypes in some structures is influenced by social environment. Abnormal motor and psychosocial behaviors resulting from this form of social/sensory deprivation may result from alterations in peptidergic and dopaminergic systems within the basal ganglia
Football: a counterpoint to the procession of pain on the Western Front, 1914-1918?
In this article, three artworks of the First World War containing images of recreational football are analysed. These three images, In the Wings of the Theatre of War, Artillery Men at Football and Gassed, span the war from its beginning to its conclusion and are discussed in relationship to the development of recreational football in the front-line area, the evolving policies of censorship and propaganda and in consideration of the national mood in Britain. The paper shows how football went from being a spontaneous and improvised pastime in the early stages of the war to a well organized entertainment by war’s end. The images demonstrate how the war was portrayed as a temporary affair by a confident nation in 1914 to a more resigned acceptance of a semi-permanent event to be endured by 1918; however, all three artworks show that the sporting spirit, and hence the fighting spirit, of the British soldier was intact
The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI
The first 42 elements of the Allen Telescope Array (ATA-42) are beginning to
deliver data at the Hat Creek Radio Observatory in Northern California.
Scientists and engineers are actively exploiting all of the flexibility
designed into this innovative instrument for simultaneously conducting surveys
of the astrophysical sky and conducting searches for distant technological
civilizations. This paper summarizes the design elements of the ATA, the cost
savings made possible by the use of COTS components, and the cost/performance
trades that eventually enabled this first snapshot radio camera. The
fundamental scientific program of this new telescope is varied and exciting;
some of the first astronomical results will be discussed.Comment: Special Issue of Proceedings of the IEEE: "Advances in Radio
Telescopes", Baars,J. Thompson,R., D'Addario, L., eds, 2009, in pres
The Allen Telescope Array Pi GHz Sky Survey I. Survey Description and Static Catalog Results for the Bootes Field
The Pi GHz Sky Survey (PiGSS) is a key project of the Allen Telescope Array.
PiGSS is a 3.1 GHz survey of radio continuum emission in the extragalactic sky
with an emphasis on synoptic observations that measure the static and
time-variable properties of the sky. During the 2.5-year campaign, PiGSS will
twice observe ~250,000 radio sources in the 10,000 deg^2 region of the sky with
b > 30 deg to an rms sensitivity of ~1 mJy. Additionally, sub-regions of the
sky will be observed multiple times to characterize variability on time scales
of days to years. We present here observations of a 10 deg^2 region in the
Bootes constellation overlapping the NOAO Deep Wide Field Survey field. The
PiGSS image was constructed from 75 daily observations distributed over a
4-month period and has an rms flux density between 200 and 250 microJy. This
represents a deeper image by a factor of 4 to 8 than we will achieve over the
entire 10,000 deg^2. We provide flux densities, source sizes, and spectral
indices for the 425 sources detected in the image. We identify ~100$ new flat
spectrum radio sources; we project that when completed PiGSS will identify 10^4
flat spectrum sources. We identify one source that is a possible transient
radio source. This survey provides new limits on faint radio transients and
variables with characteristic durations of months.Comment: Accepted for publication in ApJ; revision submitted with extraneous
figure remove
ASSOCIATION BETWEEN SKIN BARRIER DEVELOPMENT AND EARLY-ONSET ATOPIC DERMATITIS: A LONGITUDINAL BIRTH COHORT STUDY
A diagnosis of atopic dermatitis (AD) is common during infancy; however, it is unclear whether differential skin barrier development defines this period and signals disease onset in predisposed individuals. A longitudinal observational cohort study (NCT03143504) assessed the feasibility of remote skin testing from birth to monitor skin barrier maturation and model association with an AD diagnosis by 12-months of age. Biophysical testing and infrared spectroscopy were conducted at the maternity ward and family home. Tape stripping collected samples for desquamatory protease and Natural Moisturising factor (NMF) analysis. The four common European Filaggrin (FLG) risk alleles were screened. A total of 128 infants completed the study with 20% developing mild disease. Significant changes in permeability barrier function, desquamatory protease activity and molecular composition assessed spectroscopically were observed longitudinally, but only subtle evidence of differential skin barrier development was noted between infant subgroups. Common FLG risk alleles were strongly associated with early onset disease and conferred a significant reduction in NMF and water content by four weeks of age. Accounting for a family history of atopy, these parameters alongside a greater lipid/protein ratio and reduced chymotrypsin-like activity at birth were associated with AD. Measured in ambient conditions, transepidermal water loss did not signal disease risk at any stage. Skin barrier dysfunction lacked an acquired modality but was considered proportional to cohort severity and suggests that a portfolio of tests used in a community setting, has the potential to improve current AD risk evaluations from birth
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