1,029 research outputs found
Preferences for HIV testing services among men who have sex with men in the UK: A discrete choice experiment.
BACKGROUND: In the UK, approximately 4,200 men who have sex with men (MSM) are living with HIV but remain undiagnosed. Maximising the number of high-risk people testing for HIV is key to ensuring prompt treatment and preventing onward infection. This study assessed how different HIV test characteristics affect the choice of testing option, including remote testing (HIV self-testing or HIV self-sampling), in the UK, a country with universal access to healthcare. METHODS AND FINDINGS: Between 3 April and 11 May 2017, a cross-sectional online-questionnaire-based discrete choice experiment (DCE) was conducted in which respondents who expressed an interest in online material used by MSM were asked to imagine that they were at risk of HIV infection and to choose between different hypothetical HIV testing options, including the option not to test. A variety of different testing options with different defining characteristics were described so that the independent preference for each characteristic could be valued. The characteristics included where each test is taken, the sampling method, how the test is obtained, whether infections other than HIV are tested for, test accuracy, the cost of the test, the infection window period, and how long it takes to receive the test result. Participants were recruited and completed the instrument online, in order to include those not currently engaged with healthcare services. The main analysis was conducted using a latent class model (LCM), with results displayed as odds ratios (ORs) and probabilities. The ORs indicate the strength of preference for one characteristic relative to another (base) characteristic. In total, 620 respondents answered the DCE questions. Most respondents reported that they were white (93%) and were either gay or bisexual (99%). The LCM showed that there were 2 classes within the respondent sample that appeared to have different preferences for the testing options. The first group, which was likely to contain 86% of respondents, had a strong preference for face-to-face tests by healthcare professionals (HCPs) compared to remote testing (OR 6.4; 95% CI 5.6, 7.4) and viewed not testing as less preferable than remote testing (OR 0.10; 95% CI 0.09, 0.11). In the second group, which was likely to include 14% of participants, not testing was viewed as less desirable than remote testing (OR 0.56; 95% CI 0.53, 0.59) as were tests by HCPs compared to remote testing (OR 0.23; 95% CI 0.15, 0.36). In both classes, free remote tests instead of each test costing £30 was the test characteristic with the largest impact on the choice of testing option. Participants in the second group were more likely to have never previously tested and to be non-white than participants in the first group. The main study limitations were that the sample was recruited solely via social media, the study advert was viewed only by people expressing an interest in online material used by MSM, and the choices in the experiment were hypothetical rather than observed in the real world. CONCLUSIONS: Our results suggest that preferences in the context we examined are broadly dichotomous. One group, containing the majority of MSM, appears comfortable testing for HIV but prefers face-to-face testing by HCPs rather than remote testing. The other group is much smaller, but contains MSM who are more likely to be at high infection risk. For these people, the availability of remote testing has the potential to significantly increase net testing rates, particularly if provided for free
Fish to 2050 in the ASEAN region
The Association of Southeast Asian Nations (ASEAN) has emerged as a global fish producer, owing to the rapid growth of aquaculture in Southeast Asia and its large offshore fishing fleet. Fish is a regional commodity that is traded globally, and this region is at the frontline of the global trend toward meeting seafood demand by 2050. Fisheries and aquaculture are increasingly becoming a primary source of protein and micronutrients, foreign exchange, livelihoods and well-being for the population in the region. Therefore, it is imperative for ASEAN decision-makers to enhance policies nationally and regionally to maximize the synergies between socioeconomic development and protecting natural resources and the environment in the region. This paper presents a baseline (business-as-usual) projection of fish supply, net trade, consumption and nutrition in the ASEAN region to 2050
Postoperative nausea and vomiting following orthognathic surgery
The purpose of this study was to assess the incidence and risk factors associated with postoperative nausea (PON) and vomiting (POV) after orthognathic surgery. A review of the clinical records of consecutively enrolled subjects (2008–2012) at a single academic institution was conducted between 9/2013 and 3/2014. Data on the occurrence of PON and POV and potential patient-related, intraoperative, and postoperative explanatory factors were extracted from the medical records. Logistic models were used for the presence/absence of postoperative nausea and vomiting separately. Data from 204 subjects were analyzed: 63% were female, 72% Caucasian, and the median age was 19 years. Thirty-three percent had a mandibular osteotomy alone, 27% a maxillary osteotomy alone, and 40% had bimaxillary osteotomies. Sixty-seven percent experienced PON and 27% experienced POV. The most important risk factors for PON in this series were female gender, increased intravenous fluids, and the use of nitrous oxide, and for POV were race, additional procedures, and morphine administration. The incidence of PON and POV following orthognathic surgery in the current cohort of patients, after the introduction of the updated 2007 consensus guidelines for the management of postoperative nausea and vomiting, has not decreased substantially from that reported in 2003–2004
Screening current effects in Josephson junction arrays
The purpose of this work is to compare the dynamics of arrays of Josephson
junctions in presence of magnetic field in two different frameworks: the so
called XY frustrated model with no self inductance and an approach that takes
into account the screening currents (considering self inductances only). We
show that while for a range of parameters the simpler model is sufficiently
accurate, in a region of the parameter space solutions arise that are not
contained in the XY model equations.Comment: Figures available from the author
Preserving the palaeoenvironmental record in Drylands: Bioturbation and its significance for luminescence-derived chronologies
Luminescence (OSL) dating has revolutionised the understanding of Late Pleistocene dryland activity. However,
one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been
preserved intact, enabling their use as proxy indicators of past changes. This relies on stabilisation or burial
soon after deposition and a mechanism to prevent any subsequent re-mobilisation. As well as a dating
technique OSL, especially at the single grain level, can be used to gain an insight into post-depositional
processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences.
This paper explores the possible impact of bioturbation (the movement of sediment by flora and fauna) on
luminescence derived chronologies from Quaternary sedimentary deposits in Texas and Florida (USA) which
have both independent radiocarbon chronologies and archaeological evidence. These sites clearly illustrate the
ability of bioturbation to rejuvenate ancient weathered sandy bedrock and/or to alter depositional stratigraphies
through the processes of exhumation and sub-surface mixing of sediment. The use of multiple OSL replicate
measurements is advocated as a strategy for checking for bioturbated sediment. Where significant OSL
heterogeneity is found, caution should be taken with the derived OSL ages and further measurements at the
single grain level are recommended. Observations from the linear dunes of the Kalahari show them to have no
bedding structure and to have OSL heterogeneity similar to that shown from the bioturbated Texan and Florida
sites. The Kalahari linear dunes could have therefore undergone hitherto undetected post-depositional sediment
disturbance which would have implications for the established OSL chronology for the region
Many-body-QED perturbation theory: Connection to the Bethe-Salpeter equation
The connection between many-body theory (MBPT)--in perturbative and
non-perturbative form--and quantum-electrodynamics (QED) is reviewed for
systems of two fermions in an external field. The treatment is mainly based
upon the recently developed covariant-evolution-operator method for QED
calculations [Lindgren et al. Phys. Rep. 389, 161 (2004)], which has a
structure quite akin to that of many-body perturbation theory. At the same time
this procedure is closely connected to the S-matrix and the Green's-function
formalisms and can therefore serve as a bridge between various approaches. It
is demonstrated that the MBPT-QED scheme, when carried to all orders, leads to
a Schroedinger-like equation, equivalent to the Bethe-Salpeter (BS) equation. A
Bloch equation in commutator form that can be used for an "extended" or
quasi-degenerate model space is derived. It has the same relation to the BS
equation as has the standard Bloch equation to the ordinary Schroedinger
equation and can be used to generate a perturbation expansion compatible with
the BS equation also for a quasi-degenerate model space.Comment: Submitted to Canadian J of Physic
Spontaneously Generated Tensor Field Gravity
An arbitrary local theory of a symmetric two-tensor field in
Minkowski spacetime is considered, in which the equations of motion are
required to be compatible with a nonlinear length-fixing constraint leading to spontaneous Lorentz invariance violation, SLIV
( is the proposed scale for SLIV). Allowing the parameters in the Lagrangian
to be adjusted so as to be consistent with this constraint, the theory turns
out to correspond to linearized general relativity in the weak field
approximation, while some of the massless tensor Goldstone modes appearing
through SLIV are naturally collected in the physical graviton. In essence the
underlying diffeomophism invariance emerges as a necessary condition for the
tensor field not to be superfluously restricted in degrees of
freedom, apart from the constraint due to which the true vacuum in the theory
is chosen by SLIV. The emergent theory appears essentially nonlinear, when
expressed in terms of the pure Goldstone tensor modes and contains a plethora
of new Lorentz and violating couplings. However, these couplings do not
lead to physical Lorentz violation once this tensor field gravity is properly
extended to conventional general relativity.Comment: 27 pages, published version, to appear in Nuclear Physics
Effect of Nuclear Quadrupole Interaction on the Relaxation in Amorphous Solids
Recently it has been experimentally demonstrated that certain glasses display
an unexpected magnetic field dependence of the dielectric constant. In
particular, the echo technique experiments have shown that the echo amplitude
depends on the magnetic field. The analysis of these experiments results in the
conclusion that the effect seems to be related to the nuclear degrees of
freedom of tunneling systems. The interactions of a nuclear quadrupole
electrical moment with the crystal field and of a nuclear magnetic moment with
magnetic field transform the two-level tunneling systems inherent in amorphous
dielectrics into many-level tunneling systems. The fact that these features
show up at temperatures , where the properties of amorphous materials
are governed by the long-range interaction between tunneling systems,
suggests that this interaction is responsible for the magnetic field dependent
relaxation. We have developed a theory of many-body relaxation in an ensemble
of interacting many-level tunneling systems and show that the relaxation rate
is controlled by the magnetic field. The results obtained correlate with the
available experimental data. Our approach strongly supports the idea that the
nuclear quadrupole interaction is just the key for understanding the unusual
behavior of glasses in a magnetic field.Comment: 18 pages, 9 figure
Gender moderates the relationship between empathy and aggressiveness in sport: The mediating role of anger
This research investigated whether gender moderates, and anger mediates, the relationship between empathy (i.e., perspective taking and empathic concern) and aggressiveness in sport. In Study 1, perspective taking and empathic concern were negatively associated with aggressiveness, and this effect was stronger in women compared to men. In Study 2, perspective taking was a negative predictor of aggressiveness and antisocial behavior in sport, and anger mediated these relationships in women, but not in men. Our findings suggest that empathy and emotion-based strategies targeted at reducing aggressiveness in sport need to be tailored for males and females
- …