2,680 research outputs found
The impact of low energy proton damage on the operational characteristics of EPIC-MOS CCDs
The University of Tübingen 3.5 MeV Van de Graaf accelerator facility was used to investigate the effect of low energy protons on the performance of the European Photon Imaging Camera (EPIC), metal–oxide semiconductor (MOS), charge coupled devices (CCDs). Two CCDs were irradiated in different parts of their detecting areas using different proton spectra and dose rates. Iron-55 was the calibration source in all cases and was used to measure any increases in charge transfer inefficiency (CTI) and spectral resolution of the CCDs. Additional changes in the CCD bright pixel table and changes in the low X-ray energy response of the device were examined.
The Monte Carlo code Stopping Range of Ions in Matter (SRIM) was used to model the effect of a 10 MeV equivalent fluence of protons interacting with the CCD. Since the non-ionising energy loss (NIEL) function could not be applied effectively at such low proton energies. From the 10 MeV values, the expected CTI degradation could be calculated and then compared to the measured CTI changes
Introduction: looking beyond the walls
In its consideration of the remarkable extent and variety of non-university researchers, this book takes a broader view of ‘knowledge’ and ‘research’ than in the many hot debates about today’s knowledge society, ‘learning age’, or organisation of research. It goes beyond the commonly held image of ‘knowledge’ as something produced and owned by the full-time experts to take a look at those engaged in active knowledge building outside the university walls
Spread Supersymmetry
In the multiverse the scale of SUSY breaking, \tilde{m} = F_X/M_*, may scan
and environmental constraints on the dark matter density may exclude a large
range of \tilde{m} from the reheating temperature after inflation down to
values that yield a LSP mass of order a TeV. After selection effects, the
distribution for \tilde{m} may prefer larger values. A single environmental
constraint from dark matter can then lead to multi-component dark matter,
including both axions and the LSP, giving a TeV-scale LSP lighter than the
corresponding value for single-component LSP dark matter.
If SUSY breaking is mediated to the SM sector at order X^* X, only squarks,
sleptons and one Higgs doublet acquire masses of order \tilde{m}. The gravitino
mass is lighter by a factor of M_*/M_Pl and the gaugino masses are suppressed
by a further loop factor. This Spread SUSY spectrum has two versions; the
Higgsino masses are generated in one from supergravity giving a wino LSP and in
the other radiatively giving a Higgsino LSP. The environmental restriction on
dark matter fixes the LSP mass to the TeV domain, so that the squark and
slepton masses are order 10^3 TeV and 10^6 TeV in these two schemes. We study
the spectrum, dark matter and collider signals of these two versions of Spread
SUSY. The Higgs is SM-like and lighter than 145 GeV; monochromatic photons in
cosmic rays arise from dark matter annihilations in the halo; exotic short
charged tracks occur at the LHC, at least for the wino LSP; and there are the
eventual possibilities of direct detection of dark matter and detailed
exploration of the TeV-scale states at a future linear collider. Gauge coupling
unification is as in minimal SUSY theories.
If SUSY breaking is mediated at order X, a much less hierarchical spectrum
results---similar to that of the MSSM, but with the superpartner masses 1--2
orders of magnitude larger than in natural theories.Comment: 20 pages, 5 figure
Iron Status and Analysis of Efficacy and Safety of Ferric Carboxymaltose Treatment in Patients with Inflammatory Bowel Disease
Background and Aims:We analyzed iron deficiency and the therapeutic response following intravenous ferric carboxymaltose in a large single-center inflammatory bowel disease (IBD) cohort. Methods: 250 IBD patients were retrospectively analyzed for iron deficiency and iron deficiency anemia. A subgroup was analyzed regarding efficacy and side effects of iron supplementation with ferric carboxymaltose. Results: In the cohort (n = 250), 54.4% of the patients had serum iron levels 60 mu g/dl, 61.6% had ferritin >100 ng/ml, and 90.7% reached Hb >12/13 g/dl at follow-up (p < 0.0001 for all parameters vs. pretreatment values). The most frequent adverse event was a transient increase of liver enzymes with male gender as risk factor (p = 0.008, OR 8.62, 95% CI 1.74-41.66). Conclusions: Iron deficiency and anemia are frequent in IBD patients. Treatment with ferric carboxymaltose is efficious, safe and well tolerated in iron-deficient IBD patients. Copyright (C) 2011 S. Karger AG, Base
Prescribing practices of primary-care veterinary practitioners in dogs diagnosed with bacterial pyoderma
Concern has been raised regarding the potential contributions of veterinary antimicrobial use to increasing levels of resistance in bacteria critically important to human health. Canine pyoderma is a frequent, often recurrent diagnosis in pet dogs, usually attributable to secondary bacterial infection of the skin. Lesions can range in severity based on the location, total area and depth of tissue affected and antimicrobial therapy is recommended for resolution. This study aimed to describe patient signalment, disease characteristics and treatment prescribed in a large number of UK, primary-care canine pyoderma cases and to estimate pyoderma prevalence in the UK vet-visiting canine population
Instability in a marginal coral reef: the shift from natural variability to a human-dominated seascape
As global climate change drives the demise of tropical reef ecosystems, attention is turning to the suitability o refuge habitat. For the Great Barrier Reef, are there historically stable southern refugia where corals from th north might migrate as climate changes? To address this question, we present a precise chronology of margina coral reef development from Moreton Bay, southeast Queensland, Australia. Our chronology shows that ree growth was episodic, responding to natural environmental variation throughout the Holocene, and tha Moreton Bay was inhospitable to corals for about half of the past 7000 years. The only significant change ii coral species composition occurred between similar to 200 and similar to 50 years ago, following anthropogenic alterations of th, bay and its catchments. Natural historical instability of reefs, coupled with environmental degradation sinc, European colonization, suggests that Moreton Bay offers limited potential as refuge habitat for reef species or human time scales
Mathematical model of blood and interstitial flow and lymph production in the liver.
We present a mathematical model of blood and interstitial flow in the liver. The liver is treated as a lattice of hexagonal \u2018classic\u2019 lobules, which are assumed to be long enough that end effects may be neglected and a
two-dimensional problem considered. Since sinusoids and lymphatic vessels are numerous and small compared to the lobule, we use a homogenized approach, describing the sinusoidal and interstitial spaces as porous media. We model plasma filtration from sinusoids to the interstitium, lymph uptake by lymphatic ducts, and lymph outflow from the liver
surface. Our results show that the effect of the liver surface only penetrates a depth of a few lobules\u2019 thickness into the tissue. Thus, we separately consider a single lobule lying sufficiently far from all external boundaries that we may regard it as being in an infinite lattice, and also a model of the region near the liver surface. The model predicts that slightly more lymph is produced by interstitial fluid flowing through the liver surface than that taken up by the lymphatic vessels in the liver and that the on-peritonealized region of the surface of the liver results in the total lymph production (uptake by lymphatics plus fluid crossing surface) being about 5 % more than if the entire surface were covered by the Glisson\u2013peritoneal membrane. Estimates of lymph outflow through the surface of the liver are in good agreement with experimental data. We also study the effect of non-physiological values of the controlling parameters, particularly focusing
on the conditions of portal hypertension and ascites. To our knowledge, this is the first attempt to model lymph production in the liver. The model provides clinically relevant information about lymph outflow pathways and predicts the systemic response to pathological variations
A Measurement of Rb using a Double Tagging Method
The fraction of Z to bbbar events in hadronic Z decays has been measured by
the OPAL experiment using the data collected at LEP between 1992 and 1995. The
Z to bbbar decays were tagged using displaced secondary vertices, and high
momentum electrons and muons. Systematic uncertainties were reduced by
measuring the b-tagging efficiency using a double tagging technique. Efficiency
correlations between opposite hemispheres of an event are small, and are well
understood through comparisons between real and simulated data samples. A value
of Rb = 0.2178 +- 0.0011 +- 0.0013 was obtained, where the first error is
statistical and the second systematic. The uncertainty on Rc, the fraction of Z
to ccbar events in hadronic Z decays, is not included in the errors. The
dependence on Rc is Delta(Rb)/Rb = -0.056*Delta(Rc)/Rc where Delta(Rc) is the
deviation of Rc from the value 0.172 predicted by the Standard Model. The
result for Rb agrees with the value of 0.2155 +- 0.0003 predicted by the
Standard Model.Comment: 42 pages, LaTeX, 14 eps figures included, submitted to European
Physical Journal
The Hubbard model within the equations of motion approach
The Hubbard model has a special role in Condensed Matter Theory as it is
considered as the simplest Hamiltonian model one can write in order to describe
anomalous physical properties of some class of real materials. Unfortunately,
this model is not exactly solved except for some limits and therefore one
should resort to analytical methods, like the Equations of Motion Approach, or
to numerical techniques in order to attain a description of its relevant
features in the whole range of physical parameters (interaction, filling and
temperature). In this manuscript, the Composite Operator Method, which exploits
the above mentioned analytical technique, is presented and systematically
applied in order to get information about the behavior of all relevant
properties of the model (local, thermodynamic, single- and two- particle ones)
in comparison with many other analytical techniques, the above cited known
limits and numerical simulations. Within this approach, the Hubbard model is
shown to be also capable to describe some anomalous behaviors of the cuprate
superconductors.Comment: 232 pages, more than 300 figures, more than 500 reference
Rapidity and Centrality Dependence of Proton and Anti-proton Production from Au+Au Collisions at sqrt(sNN) = 130GeV
We report on the rapidity and centrality dependence of proton and anti-proton
transverse mass distributions from Au+Au collisions at sqrt(sNN) = 130GeV as
measured by the STAR experiment at RHIC. Our results are from the rapidity and
transverse momentum range of |y|<0.5 and 0.35 <p_t<1.00GeV/c. For both protons
and anti-protons, transverse mass distributions become more convex from
peripheral to central collisions demonstrating characteristics of collective
expansion. The measured rapidity distributions and the mean transverse momenta
versus rapidity are flat within |y|<0.5. Comparisons of our data with results
from model calculations indicate that in order to obtain a consistent picture
of the proton(anti-proton) yields and transverse mass distributions the
possibility of pre-hadronic collective expansion may have to be taken into
account.Comment: 4 pages, 3 figures, 1 table, submitted to PR
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