8,211 research outputs found
Performing the Union: the PrĂźm Decision and the European dream
In 2005, seven European countries signed the so-called PrĂźm Treaty to increase transnational collaboration in combating international crime, terrorism and illegal immigration. Three years later, the Treaty was adopted into EU law. EU member countries are obliged to have systems in place to allow authorities of other member states access to nationally held data on DNA, fingerprints, and vehicles by August 2011. In this paper, we discuss the conditions of possibility for the PrĂźm network to emerge, and argue that rather than a linear story of technological and political convergence and harmonisation, the (hi)story of PrĂÂźm is heterogeneous and patchy. This is reflected also in the early stages of implementing the PrĂźm Decision which proves to be more difficult than it was hoped by the drivers of the PrĂźm process. In this sense, the PrĂźm network sits uncomfortably with success stories of forensic science (many of which served the goal of justifying the expansion of technological and surveillance systems). Instead of telling a story of heroic science, the story of PrĂźm articulates the European dream: One in which goods, services, and people live and travel freely and securely
Distinct DNA repair pathways involving RecA and nonhomologous end joining in Mycobacterium smegmatis
Mycobacterium smegmatis was used to study the relationship between DNA repair processes involving RecA and nonhomologous end joining (NHEJ). The effect of gene deletions in recA and/or in two genes involved in NHEJ (ku and ligD) was tested on the ability of bacteria to join breaks in plasmids transformed into them and in their response to chemicals that damage DNA. The results provide in vivo evidence that only NHEJ is required for the repair of noncompatible DNA ends. By contrast, the response of mycobacteria to mitomycin C preferentially involved a RecA-dependent pathway
Vibrational spectra of C60C8H8 and C70C8H8 in the rotor-stator and polymer phases
C60-C8H8 and C70-C8H8 are prototypes of rotor-stator cocrystals. We present
infrared and Raman spectra of these materials and show how the rotor-stator
nature is reflected in their vibrational properties. We measured the
vibrational spectra of the polymer phases poly(C60C8H8) and poly(C70C8H8)
resulting from a solid state reaction occurring on heating. Based on the
spectra we propose a connection pattern for the fullerene in poly(C60C8H8),
where the symmetry of the C60 is D2h. On illuminating the C60-C8H8 cocrystal
with green or blue light a photochemical reaction was observed leading to a
similar product to that of the thermal polymerization.Comment: 26 pages, 8 figures, to appear in Journal of Physical Chemistry B 2nd
version: minor changes in wording, accepted version by journa
Low serum 25-hydroxyvitamin D concentrations are associated with non-alcoholic fatty liver disease in adolescents independent of adiposity
Background and Aims: Non-alcoholic fatty liver disease (NAFLD) and serum 25-hydroxyvitamin D (s25[OH]D) concentrations are both associated with adiposity and insulin resistance (IR) and thus may be pathogenically linked. We aimed to determine the prevalence of vitamin D deficiency in adolescents with NAFLD and to investigate the prospective and cross-sectional associations between s25[OH]D concentrations and NAFLD. Methods: Participants in the population-based West Australian Pregnancy (Raine) Cohort had seasonally adjusted s25(OH)D concentrations determined at ages 14 and then 17 years. NAFLD was diagnosed at 17 years using liver ultrasonography. Associations were examined after adjusting for potential confounders. Odds ratios (ORs) and confidence intervals (CIs) are reported per standard deviation in s25(OH)D concentrations. Results: NAFLD was present in 16% (156/994) of adolescents. The majority of participants with NAFLD had either insufficient (51%) or deficient (17%) vitamin D status. s25(OH)D concentrations at 17 years were inversely associated with risk of NAFLD (OR 0.74, 95% CI 0.56, 0.97; Pâ=â0.029), after adjusting for sex, race, physical activity, television/computer viewing, body mass index, and IR. The effect of s25(OH)D concentrations at 17 years was minimally affected after further adjusting for s25(OH)D concentrations at 14 years (OR 0.76, 95% CI 0.56, 1.03; Pâ=â0.072). Conclusions: Lower s25(OH)D concentrations are significantly associated with NAFLD, independent of adiposity and IR. Screening for vitamin D deficiency in adolescents at risk of NAFLD is appropriate, and clinical trials investigating the effect of vitamin D supplementation in the prevention and treatment of NAFLD may be warranted
Star Formation History up to z = 7.4: Implications for Gamma-Ray Bursts and the Cosmic Metallicity Evolution
The current Swift sample of gamma-ray bursts (GRBs) with measured redshifts
allows to test the assumption that GRBs trace the star formation in the
Universe. Some authors have claimed that the rate of GRBs increases with cosmic
redshift faster than the star formation rate, whose cause is not known yet. In
this paper, I investigate the possibility for interpreting the observed
discrepancy between the GRB rate history and the star formation rate history by
the cosmic metallicity evolution, motivated by the observation that the cosmic
metallicity evolves with redshift and GRBs prefer to occur in low metallicity
galaxies. First, I derive a star formation history up to redshift z=7.4 from an
updated sample of star formation rate densities obtained by adding the new UV
measurements of Bouwens et al. and the new UV and infrared measurements of
Reddy et al. to the existing sample compiled by Hopkins & Beacom. Then,
adopting a simple model for the relation between the GRB production and the
cosmic metallicity history as proposed by Langer & Norman, I show that the
observed redshift distribution of the Swift GRBs can be reproduced with a
fairly good accuracy. Although the results are limited by the small size of the
GRB sample and the poorly understood selection biases in detection and
localization of GRBs and in redshift determination, they suggest that GRBs
trace both the star formation and the metallicity evolution. If the star
formation history can be accurately measured with other approaches, which is
presumably achievable in the near future, it will be possible to determine the
cosmic metallicity evolution with the study on the redshift distribution of
GRBs.Comment: 16 pages, 11 figures and 2 tables, accepted for publication in MNRAS.
New version contains an updated star formation history and a review on the
cosmic metallicity measuremen
Global optical/infrared - X-ray correlations in X-ray binaries: quantifying disc and jet contributions
The optical/near-infrared (OIR) region of the spectra of low-mass X-ray
binaries appears to lie at the intersection of a variety of different emission
processes. In this paper we present quasi-simultaneous OIR - X-ray observations
of 33 XBs in an attempt to estimate the contributions of various emission
processes in these sources, as a function of X-ray state and luminosity. A
global correlation is found between OIR and X-ray luminosity for low-mass black
hole candidate XBs (BHXBs) in the hard X-ray state, of the form L_OIR is
proportional to Lx^0.6. This correlation holds over 8 orders of magnitude in Lx
and includes data from BHXBs in quiescence and at large distances (LMC and
M31). A similar correlation is found in low-mass neutron star XBs (NSXBs) in
the hard state. For BHXBs in the soft state, all the near-infrared (NIR) and
some of the optical emission is suppressed below the correlation, a behaviour
indicative of the jet switching off/on in transition to/from the soft state. We
compare these relations to theoretical models of a number of emission
processes. We find that X-ray reprocessing in the disc and emission from the
jets both predict a slope close to 0.6 for BHXBs, and both contribute to the
OIR in BHXBs in the hard state, the jets producing ~90 percent of the NIR
emission at high luminosities. X-ray reprocessing dominates the OIR in NSXBs in
the hard state, with possible contributions from the jets (only at high
luminosity) and the viscously heated disc. We also show that the optically
thick jet spectrum of BHXBs extends to near the K-band. (abridged)Comment: Accepted for publication in MNRAS; 19 pages, 7 figure
Sampling, isolating and identifying microplastics ingested by fish and invertebrates
Microplastic debris (<5 mm) is a prolific environmental pollutant, found worldwide in marine, freshwater and terrestrial ecosystems. Interactions between biota and microplastics are prevalent, and there is growing evidence that microplastics can incite significant health effects in exposed organisms. To date, the methods used to quantify such interactions have varied greatly between studies. Here, we critically review methods for sampling, isolating and identifying microplastics ingested by environmentally and laboratory exposed fish and invertebrates. We aim to draw attention to the strengths and weaknesses of the suite of published microplastic extraction and enumeration techniques. Firstly, we highlight the risk of microplastic losses and accumulation during biotic sampling and storage, and suggest protocols for mitigating contamination in the field and laboratory. We evaluate a suite of methods for extracting microplastics ingested by biota, including dissection, depuration, digestion and density separation. Lastly, we consider the applicability of visual identification and chemical analyses in categorising microplastics. We discuss the urgent need for the standardisation of protocols to promote consistency in data collection and analysis. Harmonized methods will allow for more accurate assessment of the impacts and risks microplastics pose to biota and increase comparability between studies
Expressions 1980
Expressions contains selected work from the 1980 Creative Writing Contest winners and honorable mentions, Campus Chronicle Photography Contest entrants, and the Commercial Art students at Des Moines Area Community College. Design, typography and layout was done by Journalism students.https://openspace.dmacc.edu/expressions/1002/thumbnail.jp
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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