The views of general practitioners and practice nurses towards the barriers and facilitators of proactive, internet-based chlamydia screening for reaching young heterosexual men

Background: Chlamydia trachomatis is a common bacterial sexually transmitted infection (STI), which disproportionately affects young people under 25 years. Commonly, more women are offered screening than men. This study obtained the views of general practitioners and practice nurses towards Internet-based screening and assessed levels of support for the development of proactive screening targeting young heterosexual men via the Internet. Methods: Semi-structured telephone interviews with 10 general practitioners and 8 practice nurses, across Central Scotland. Topics covered: experience of screening heterosexual men for chlamydia, views on the use of the Internet as a way to reach young men for chlamydia screening, beliefs about the potential barriers and facilitators to Internet-based screening. Transcripts from audio recordings were analysed with Framework Analysis, using QSR NVivo10. Results: Experiences of chlamydia screening were almost exclusively with women, driven by the nature of consultations and ease of raising sexual health issues with female patients; few practice nurses reported seeing men during consultations. All participants spoke in favour of Internet-based screening for young men. Participants reported ease of access and convenience as potential facilitators of an Internet-based approach but anonymity and confidentiality could be potential barriers and facilitators to the success of an Internet approach to screening. Concerns over practical issues as well as those pertaining to gender and socio-cultural issues were raised. Conclusions: Awareness of key barriers and facilitators, such as confidentiality, practicality and socio-cultural influences, will inform the development of an Internet-based approach to screening. However, this approach may have its limits in terms of being able to tackle wider social and cultural barriers, along with shifts in young people's and health professionals' attitudes towards screening. Nevertheless, employing innovative efforts as part of a multi-faceted approach is required to ensure effective interventions reach the policy agenda

Minimal Flavour Violation and Beyond

Starting from the effective-theory framework for Minimal Flavour Violation, we give a systematic definition of next-to-minimal (quark) flavour violation in terms of a set of spurion fields exhibiting a particular hierarchy with respect to a small (Wolfenstein-like) parameter. A few illustrative examples and their consequences for charged and neutral decays with different quark chiralities are worked out in some detail. Our framework can be used as a model-independent classification scheme for the parameterization of flavour structure from physics beyond the Standard Model.Comment: 17 pages, no figures, phenomenological discussion extended, references adde

Spitzer/MIPS Observations of Stars in the Beta Pictoris Moving Group

We present Multiband Imaging Photometer for Spitzer (MIPS) observations at 24 and 70 microns for 30 stars, and at 160 microns for a subset of 12 stars, in the nearby (~30 pc), young (~12 Myr) Beta Pictoris Moving Group (BPMG). In several cases, the new MIPS measurements resolve source confusion and background contamination issues in the IRAS data for this sample. We find that 7 members have 24 micron excesses, implying a debris disk fraction of 23%, and that at least 11 have 70 micron excesses (disk fraction of >=37%). Five disks are detected at 160 microns (out of a biased sample of 12 stars observed), with a range of 160/70 flux ratios. The disk fraction at 24 and 70 microns, and the size of the excesses measured at each wavelength, are both consistent with an "inside-out" infrared excess decrease with time, wherein the shorter-wavelength excesses disappear before longer-wavelength excesses, and consistent with the overall decrease of infrared excess frequency with stellar age, as seen in Spitzer studies of other young stellar groups. Assuming that the infrared excesses are entirely due to circumstellar disks, we characterize the disk properties using simple models and fractional infrared luminosities. Optically thick disks, seen in the younger TW Hya and eta Cha associations, are entirely absent in the BPMG. Additional flux density measurements at 24 and 70 microns are reported for nine Tucanae-Horologium Association member stars. Since this is <20% of the association membership, limited analysis on the complete disk fraction of this association is possible.Comment: Accepted for Ap

Russell Lecture: Dark Star Formation and Cooling Instability

Optically thin cooling gas at most temperatures above 30K will make condensations by pressure pushing material into cool dense regions. This works without gravity. Cooling condensations will flatten and become planar/similarity solutions. Most star formation may start from cooling condensations - with gravity only important in the later stages. The idea that some of the dark matter could be pristine white dwarfs that condensed slowly on to planetary sized seeds without firing nuclear reactions is found lacking. However, recent observations indicate fifty times more halo white dwarfs than have been previously acknowledged; enough to make the halo fraction observed as MACHOS. A cosmological census shows that only 1% of the mass of the Universe is of known constitution.Comment: 32 Pages, Latex (uses aastex & natbib), 5 eps figures, submitted to ApJ April 200

Worldvolume Superalgebra Of BLG Theory With Nambu-Poisson Structure

Recently it was proposed that the Bagger-Lambert-Gustavsson theory with Nambu-Poisson structure describes an M5-brane in a three-form flux background. In this paper we investigate the superalgebra associated with this theory. We derive the central charges corresponding to M5-brane solitons in 3-form backgrounds. We also show that double dimensional reduction of the superalgebra gives rise to the Poisson bracket terms of a non-commutative D4-brane superalgebra. We provide interpretations of the D4-brane charges in terms of spacetime intersections.Comment: 23 pages; references added, section 4 clarification

The Trans-Pacific Partnership Agreement: Looking Ahead to the Next Steps

Pressure has been building for the conclusion of the 12-country Trans-Pacific Partnership (TPP) negotiations. Getting the deal done is important, but the TPP is not just another free trade agreement (FTA). It represents the chance to set a trade agenda for the future across a wide range of topics for countries throughout the Asia-Pacific region. This means that the agreement should not be settled in haste. More importantly, it also means that key decisions need to be reached about broader issues related to the institutional structure of the TPP. These decisions must be made now, before the deal is closed, on issues such as how to create the TPP as a living agreement, the formation of a TPP Secretariat, and the clarification of entry conditions for future members such as the People’s Republic of China (PRC). These choices must be made deliberately and carefully even while officials are struggling with reaching closure on the most highly sensitive issues still remaining in the agreement. It will not be easy, but wise decisions are necessary now to ensure the long-term success of the TPP

The evolution and ecology of land ownership

Land ownership norms play a central role in social-ecological systems, and have been studied extensively as a component of ethnographies. Yet only recently has the distribution of land ownership norms across cultures been examined from evolutionary and ecological perspectives. Here we incorporate evolutionary and macroecological modelling to test associations between land ownership norms and environmental, subsistence, and cultural contact predictors for societies in the Bantu language family. We find that Bantu land ownership norms likely evolved on a unilinear trajectory, but not necessarily one requiring consistent increase in exclusivity as suggested by prior theory. Our macroecological analyses suggest that Bantu societies are more likely to have some form of ownership when their neighbors also do. We also find an effect of environmental productivity, supporting resource defensibility theory, which posits that land ownership is more likely where productivity is predictable. We find less support for a proposed link between agricultural intensification and land ownership. Overall, we demonstrate the value of combining analytical approaches from evolution and ecology to test diverse hypotheses on land ownership across a range of disciplines.1. Introduction 2. Materials and methods 2.1 Data 2.2 Phylogenetic analyses of evolution of land ownership 2.3 Multi-model inference of drivers of spatial patterns in land ownership 3. Results 3.1 Evolutionary trajectories of land ownership 3.2 Drivers of spatial variation in land ownership 4. Discussio

Relativistic theory of magnetic scattering of x rays: Application to ferromagnetic iron

We present a detailed description of a first-principles formalism for magnetic scattering of circularly polar- ized x rays from solids in the framework of the fully relativistic spin-polarized multiple-scattering theory. The scattering amplitudes are calculated using a standard time-dependent perturbation theory to second order in the electron-photon interaction vertex. Particular attention is paid to understanding the relative importance of the positive- and negative-energy solutions of the Dirac equation to the scattering amplitude. The advantage of the present theory as compared with other recent works on magnetic x-ray scattering is that, being fully relativistic, spin-orbit coupling and spin-polarization effects are treated on an equal footing. Second, the electron Green’s function expressed in terms of the path operators in the multiple-scattering theory allows us to include the contribution of the crystalline environment to the scattering amplitude. To illustrate the use of the method we have done calculations on the anomalous magnetic scattering at the K , L_II , and L_III absorption edges of ferromagnetic iron

Anatomy of the Soft-Photon Approximation in Hadron-Hadron Bremsstrahlung

A modified Low procedure for constructing soft-photon amplitudes has been used to derive two general soft-photon amplitudes, a two-s-two-t special amplitude $M^{TsTts}_{\mu}$ and a two-u-two-t special amplitude $M^{TuTts}_{\mu}$, where s, t and u are the Mandelstam variables. $M^{TsTts}_{\mu}$ depends only on the elastic T-matrix evaluated at four sets of (s,t) fixed by the requirement that the amplitude be free of derivatives ($\partial$T/$\partial$s and /or $\partial$T/$\partial t$). Likewise $M^{TuTts}_{\mu}$ depends only on the elastic T-matrix evaluated at four sets of (u,t). In deriving these amplitudes, we impose the condition that $M^{TsTts}_{\mu}$ and $M^{TuTts}_{\mu}$ reduce to $\bar{M}^{TsTts}_{\mu}$ and $\bar{M}^{TuTts}_{\mu}$, respectively, their tree level approximations. The amplitude $\bar{M}^{TsTts}_{\mu}$ represents photon emission from a sum of one-particle t-channel exchange diagrams and one-particle s-channel exchange diagrams, while the amplitude $\bar{M}^{TuTts} _{\mu}$ represents photon emission from a sum of one-particle t-channel exchange diagrams and one-particle u-channel exchange diagrams. The precise expressions for $\bar{M}^{TsTts}_{\mu}$ and $\bar{M}^{TuTts}_{\mu}$ are determined by using the radiation decomposition identities of Brodsky and Brown. We point out that it is theoretically impossible to describe all bremsstrahlung processes by using only a single class of soft-photon amplitudes. At least two different classes are required: the amplitudes which depend on s and t or the amplitudes which depend on u and t. When resonance effects are important, the amplitude $M^{TsTts}_{\mu}$, not $M^{Low(st)}_{\mu}$, should be used. For processes with strong u-channel exchange effects, the amplitude $M^{TuTts}_{\mu}$ should be the first choice.Comment: 49 pages report # LA-UR-92-270

Improving the sensitivity of Higgs boson searches in the golden channel

Leptonic decays of the Higgs boson in the ZZ* channel yield what is known as the golden channel due to its clean signature and good total invariant mass resolution. In addition, the full kinematic distribution of the decay products can be reconstructed, which, nonetheless, is not taken into account in traditional search strategy relying only on measurements of the total invariant mass. In this work we implement a type of multivariate analysis known as the matrix element method, which exploits differences in the full production and decay matrix elements between the Higgs boson and the dominant irreducible background from q bar{q} -> ZZ*. Analytic expressions of the differential distributions for both the signal and the background are also presented. We perform a study for the Large Hadron Collider at sqrt{s}=7 TeV for Higgs masses between 175 and 350 GeV. We find that, with an integrated luminosity of 2.5 fb^-1 or higher, improvements in the order of 10 - 20 % could be obtained for both discovery significance and exclusion limits in the high mass region, where the differences in the angular correlations between signal and background are most pronounced.Comment: 31 pages, 8 figures. v2: Minus signs in definitions of angles corrected. Typos fixed. Reference added. Cosmetic changes to Figure 4. Additional sentence added for clarificatio