7,108 research outputs found
Rights-based reasoning in discussions about lesbian and gay issues: implications for moral educators
Despite a paucity of psychological research exploring the interface between lesbian and gay issues and human rights, a human rights framework has been widely adopted in debates to gain equality for lesbians and gay men. Given this prominence within political discourse of human rights as a framework for the promotion of positive social change for lesbians and gay men, the aim of this study was to explore the extent to which rights-based arguments are employed when talking about lesbian and gay issues in a social context. An analysis of six focus group discussions with students showed that when lesbian and gay issues are discussed, rights-based reasoning is employed intermittently, and in relation to certain issues more so than others. The implications of these findings for moral education aimed at promoting positive social change for lesbians and gay men are discussed.</p
Comparison of bulk milk antibody and youngstock serology screens for determining herd status for Bovine Viral Diarrhoea Virus
BACKGROUND: This paper examines the use of Bulk Milk antibody (BM Ab), Youngstock (YS) serology (Check Tests) and Bulk Milk PCR (BM PCR) for determining the presence or absence of animals persistently infected (PI) with Bovine Viral Diarrhoea Virus (BVDV) within a herd. Data is presented from 26 herds where average herd sizes were 343 and 98 animals for dairy and beef units respectively. Seventeen herds had sufficient data to analyse using Receiver Operating Characteristic (ROC) and probability curves enabling calculation of the sensitivity and specificity of BM Ab and YS Check tests for determining the presence of PI animals within herds in this dataset. RESULTS: Using BM Ab to screen a herd for the presence of PI animals, achieved a herd level sensitivity and specificity of 80.00 % (44.39–97.48 %) and 85.71 % (42.13–99.64 %) respectively (95 % confidence intervals quoted). Sensitivity and specificity of YS Check Tests at a cut off of 3/10 Ab positive YS were 81.82 % (48.22–97.72 %) and 66.67 % (22.28–95.67 %) respectively (95 % confidence interval). These results were achieved by comparing the screening tests to whole herd PI searches that took place 1–19 months after the initial screen with a mean interval of 8 months. Removal of this delay by taking BM samples on the day of a whole herd test and simulating a YS Check Test from the herd test data produced improvements in the reliability of the Check Tests. BM Ab sensitivity and specificity remained unchanged. However, the Check Test sensitivity and specificity improved to 90.9 % (58.72–99.77 %) and 100 % (54.07–100 %) respectively (95 % confidence interval) at a cut of off 2.5/10 Ab positive animals. Our limited BM PCR results identified 5/23 dairy farms with a positive BM PCR result; two contained milking PIs, two had non-milking PIs and another had no PIs identified. CONCLUSIONS: Delaying a PI search following an initial herd screen decreased the diagnostic accuracy and relevance of our results. With careful interpretation, longitudinal surveillance using a combination of the techniques discussed can successfully determine farm status and therefore allow changes in BVDV status to be detected early, thus enabling prompt action in the event of a BVDV incursion
Two-Loop Renormalization Group Equations for Soft Supersymmetry-Breaking Couplings
We compute the two-loop renormalization group equations for all soft
supersymmetry-breaking couplings in a general softly broken N=1 supersymmetric
model. We also specialize these results to the Minimal Supersymmetric Standard
Model.Comment: 26 pages. [v4: Signs of equations (4.2) and (4.3) are fixed.
Double Parton Scattering Singularity in One-Loop Integrals
We present a detailed study of the double parton scattering (DPS)
singularity, which is a specific type of Landau singularity that can occur in
certain one-loop graphs in theories with massless particles. A simple formula
for the DPS singular part of a four-point diagram with arbitrary
internal/external particles is derived in terms of the transverse momentum
integral of a product of light cone wavefunctions with tree-level matrix
elements. This is used to reproduce and explain some results for DPS
singularities in box integrals that have been obtained using traditional loop
integration techniques. The formula can be straightforwardly generalised to
calculate the DPS singularity in loops with an arbitrary number of external
particles. We use the generalised version to explain why the specific MHV and
NMHV six-photon amplitudes often studied by the NLO multileg community are not
divergent at the DPS singular point, and point out that whilst all NMHV
amplitudes are always finite, certain MHV amplitudes do contain a DPS
divergence. It is shown that our framework for calculating DPS divergences in
loop diagrams is entirely consistent with the `two-parton GPD' framework of
Diehl and Schafer for calculating proton-proton DPS cross sections, but is
inconsistent with the `double PDF' framework of Snigirev.Comment: 29 pages, 8 figures. Minor corrections and clarifications added.
Version accepted for publication in JHE
The Social and Political Dimensions of the Ebola Response: Global Inequality, Climate Change, and Infectious Disease
The 2014 Ebola crisis has highlighted public-health vulnerabilities in Liberia, Sierra
Leone, and Guinea – countries ravaged by extreme poverty, deforestation and
mining-related disruption of livelihoods and ecosystems, and bloody civil wars in
the cases of Liberia and Sierra Leone. Ebola’s emergence and impact are grounded
in the legacy of colonialism and its creation of enduring inequalities within African
nations and globally, via neoliberalism and the Washington Consensus. Recent
experiences with new and emerging diseases such as SARS and various strains of
HN influenzas have demonstrated the effectiveness of a coordinated local and
global public health and education-oriented response to contain epidemics. To what
extent is international assistance to fight Ebola strengthening local public health and
medical capacity in a sustainable way, so that other emerging disease threats, which
are accelerating with climate change, may be met successfully? This chapter
considers the wide-ranging socio-political, medical, legal and environmental factors
that have contributed to the rapid spread of Ebola, with particular emphasis on the
politics of the global and public health response and the role of gender, social
inequality, colonialism and racism as they relate to the mobilization and
establishment of the public health infrastructure required to combat Ebola and other
emerging diseases in times of climate change
Measuring the Invisible Higgs Width at the 7 and 8 TeV LHC
The LHC is well on track toward the discovery or exclusion of a light
Standard Model (SM)-like Higgs boson. Such a Higgs has a very small SM width
and can easily have large branching fractions to physics beyond the SM, making
Higgs decays an excellent opportunity to observe new physics. Decays into
collider-invisible particles are particularly interesting as they are
theoretically well motivated and relatively clean experimentally. In this work
we estimate the potential of the 7 and 8 TeV LHC to observe an invisible Higgs
branching fraction. We analyze three channels that can be used to directly
study the invisible Higgs branching ratio at the 7 TeV LHC: an invisible Higgs
produced in association with (i) a hard jet; (ii) a leptonic Z; and (iii)
forward tagging jets. We find that the last channel, where the Higgs is
produced via weak boson fusion, is the most sensitive, allowing branching
fractions as small as 40% to be probed at 20 inverse fb for masses in the range
between 120 and 170 GeV, including in particular the interesting region around
125 GeV. We provide an estimate of the 8 TeV LHC sensitivity to an
invisibly-decaying Higgs produced via weak boson fusion and find that the reach
is comparable to but not better than the reach at the 7 TeV LHC. We further
estimate the discovery potential at the 8 TeV LHC for cases where the Higgs has
substantial branching fractions to both visible and invisible final states.Comment: 23 pages, 7 figures. v2: version published in JHEP. 8 TeV analysis
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On the Integrand-Reduction Method for Two-Loop Scattering Amplitudes
We propose a first implementation of the integrand-reduction method for
two-loop scattering amplitudes. We show that the residues of the amplitudes on
multi-particle cuts are polynomials in the irreducible scalar products
involving the loop momenta, and that the reduction of the amplitudes in terms
of master integrals can be realized through polynomial fitting of the
integrand, without any apriori knowledge of the integral basis. We discuss how
the polynomial shapes of the residues determine the basis of master integrals
appearing in the final result. We present a four-dimensional constructive
algorithm that we apply to planar and non-planar contributions to the 4- and
5-point MHV amplitudes in N=4 SYM. The technique hereby discussed extends the
well-established analogous method holding for one-loop amplitudes, and can be
considered a preliminary study towards the systematic reduction at the
integrand-level of two-loop amplitudes in any gauge theory, suitable for their
automated semianalytic evaluation.Comment: 26 pages, 11 figure
Central Exclusive Production in QCD
We investigate the theoretical description of the central exclusive
production process, h1+h2 -> h1+X+h2. Taking Higgs production as an example, we
sum logarithmically enhanced corrections appearing in the perturbation series
to all orders in the strong coupling. Our results agree with those originally
presented by Khoze, Martin and Ryskin except that the scale appearing in the
Sudakov factor, mu=0.62 \sqrt{\hat{s}}, should be replaced with
mu=\sqrt{\hat{s}}, where \sqrt{\hat{s}} is the invariant mass of the centrally
produced system. We confirm this result using a fixed-order calculation and
show that the replacement leads to approximately a factor 2 suppression in the
cross-section for central system masses in the range 100-500 GeV.Comment: 41 pages, 19 figures; minor typos fixed; version published in JHE
Effects of ocean acidification on invertebrate settlement at volcanic CO<inf>2</inf> vents
We present the first study of the effects of ocean acidification on settlement of benthic invertebrates and microfauna. Artificial collectors were placed for 1 month along pH gradients at CO2 vents off Ischia (Tyrrhenian Sea, Italy). Seventy-nine taxa were identified from six main taxonomic groups (foraminiferans, nematodes, polychaetes, molluscs, crustaceans and chaetognaths). Calcareous foraminiferans, serpulid polychaetes, gastropods and bivalves showed highly significant reductions in recruitment to the collectors as pCO2 rose from normal (336-341 ppm, pH 8.09-8.15) to high levels (886-5,148 ppm) causing acidified conditions near the vents (pH 7.08-7.79). Only the syllid polychaete Syllis prolifera had higher abundances at the most acidified station, although a wide range of polychaetes and small crustaceans was able to settle and survive under these conditions. A few taxa (Amphiglena mediterranea, Leptochelia dubia, Caprella acanthifera) were particularly abundant at stations acidified by intermediate amounts of CO2 (pH 7. 41-7.99). These results show that increased levels of CO2 can profoundly affect the settlement of a wide range of benthic organisms. © 2010 Springer-Verlag
Single Cut Integration
We present an analytic technique for evaluating single cuts for one-loop
integrands, where exactly one propagator is taken to be on shell. Our method
extends the double-cut integration formalism of one-loop amplitudes to the
single-cut case. We argue that single cuts give meaningful information about
amplitudes when taken at the integrand level. We discuss applications to the
computation of tadpole coefficients.Comment: v2: corrected typo in abstrac
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