Light Z' Bosons at the Tevatron

New gauge bosons with Standard Model-like couplings to leptons are constrained by collider searches to be heavier than approximately ~1 TeV. A Z' boson with suppressed couplings to leptons, however, could be much lighter and possess substantial couplings to Standard Model quarks. In this article, we consider a new leptophobic Z' gauge boson as a simple and well motivated extension of the Standard Model, and discuss several of its possible signatures at the Tevatron. We find that three of the recent anomalies reported from the Tevatron - in particular the top-quark forward-backward asymmetry and excesses in the 3b and W + 2 jets final states - could be explained by a new Z' with a mass of approximately 150 GeV, relatively large couplings to quarks, and suppressed couplings to electrons and muons. Moreover, we find that such a particle could also mediate the interactions of dark matter, leading to potentially interesting implications for direct detection experiments.Comment: 12 pages, 7 figures. v2, v3: updated references. v4: updated to match published version, including minor revisions to figures 1 and

Dark Force Detection in Low Energy e-p Collisions

We study the prospects for detecting a light boson X with mass m_X < 100 MeV at a low energy electron-proton collider. We focus on the case where X dominantly decays to e+ e- as motivated by recent "dark force" models. In order to evade direct and indirect constraints, X must have small couplings to the standard model (alpha_X 10 MeV). By comparing the signal and background cross sections for the e- p e+ e- final state, we conclude that dark force detection requires an integrated luminosity of around 1 inverse attobarn, achievable with a forthcoming JLab proposal.Comment: 38 pages, 19 figures; v2, references adde

GRIPS - Gamma-Ray Imaging, Polarimetry and Spectroscopy

We propose to perform a continuously scanning all-sky survey from 200 keV to 80 MeV achieving a sensitivity which is better by a factor of 40 or more compared to the previous missions in this energy range. The Gamma-Ray Imaging, Polarimetry and Spectroscopy (GRIPS) mission addresses fundamental questions in ESA's Cosmic Vision plan. Among the major themes of the strategic plan, GRIPS has its focus on the evolving, violent Universe, exploring a unique energy window. We propose to investigate $\gamma$-ray bursts and blazars, the mechanisms behind supernova explosions, nucleosynthesis and spallation, the enigmatic origin of positrons in our Galaxy, and the nature of radiation processes and particle acceleration in extreme cosmic sources including pulsars and magnetars. The natural energy scale for these non-thermal processes is of the order of MeV. Although they can be partially and indirectly studied using other methods, only the proposed GRIPS measurements will provide direct access to their primary photons. GRIPS will be a driver for the study of transient sources in the era of neutrino and gravitational wave observatories such as IceCUBE and LISA, establishing a new type of diagnostics in relativistic and nuclear astrophysics. This will support extrapolations to investigate star formation, galaxy evolution, and black hole formation at high redshifts.Comment: to appear in Exp. Astron., special vol. on M3-Call of ESA's Cosmic Vision 2010; 25 p., 25 figs; see also www.grips-mission.e

'Ain't it a Ripping Night': Alcoholism and the Legacies of Empire in Salman Rushdie's Midnight's Children.

In the era of decolonisation that followed the Second World War, various authors sought to engage with India and the Empire’s past anew throughout their novels, identifying medicine and illness as key parts of Imperial authority and colonial experience. Salman Rushdie’s approach to the Raj in Midnight’s Children (1981) focused on the broad sweep of colonial life, juxtaposing the political and the personal. This article argues that Rushdie explores the history of colonial India by employing alcohol and alcoholism as lenses through which to explore the cultural, political and medical legacies of Empire. Through analysis of Midnight’s Children as well as a range of medical sources related to alcohol and inebriation, it will illustrate how drinking is central to Rushdie’s approach to secular and religious identities in newly independent India, as well as a means of satirising and undermining the supposed benefit that Empire presented to India and Indians

The prevalence of common mental disorders and PTSD in the UK military: using data from a clinical interview-based study

<p>Abstract</p> <p>Background</p> <p>The mental health of the Armed Forces is an important issue of both academic and public interest. The aims of this study are to: a) assess the prevalence and risk factors for common mental disorders and post traumatic stress disorder (PTSD) symptoms, during the main fighting period of the Iraq War (TELIC 1) and later deployments to Iraq or elsewhere and enlistment status (regular or reserve), and b) compare the prevalence of depression, PTSD symptoms and suicidal ideation in regular and reserve UK Army personnel who deployed to Iraq with their US counterparts.</p> <p>Methods</p> <p>Participants were drawn from a large UK military health study using a standard two phase survey technique stratified by deployment status and engagement type. Participants undertook a structured telephone interview including the Patient Health Questionnaire (PHQ) and a short measure of PTSD (Primary Care PTSD, PC-PTSD). The response rate was 76% (821 participants).</p> <p>Results</p> <p>The weighted prevalence of common mental disorders and PTSD symptoms was 27.2% and 4.8%, respectively. The most common diagnoses were alcohol abuse (18.0%) and neurotic disorders (13.5%). There was no health effect of deploying for regular personnel, but an increased risk of PTSD for reservists who deployed to Iraq and other recent deployments compared to reservists who did not deploy. The prevalence of depression, PTSD symptoms and subjective poor health were similar between regular US and UK Iraq combatants.</p> <p>Conclusion</p> <p>The most common mental disorders in the UK military are alcohol abuse and neurotic disorders. The prevalence of PTSD symptoms remains low in the UK military, but reservists are at greater risk of psychiatric injury than regular personnel.</p

What the Tevatron Found?

The CDF collaboration has reported a 4.1\sigma\ excess in their lepton, missing energy, and dijets channel. This excess, which takes the form of an approximately Gaussian peak centered at a dijet invariant mass of 147 GeV, has provoked a great deal of experimental and theoretical interest. Although the D\O\ collaboration has reported that they do not observe a signal consistent with CDF, there is currently no widely accepted explanation for the discrepancy between these two experiments. A resolution of this issue is of great importance---not least because it may teach us lessons relevant for future searches at the LHC---and it will clearly require additional information. In this paper, we consider the ability of the Tevatron and LHC detectors to observe evidence associated with the CDF excess in a variety of channels. We also discuss the ability of selected kinematic distributions to distinguish between Standard Model explanations of the observed excess and various new physics scenarios.Comment: 14 pages, 4 figures, 2 tables. Accepted for publication by JHEP. v2: minor changes to text and figure

Vitamin D supplementation to prevent tuberculosis infection in South African schoolchildren: multicentre phase 3 double-blind randomised placebo-controlled trial (ViDiKids)

BACKGROUND: Relationships between vitamin D status, parathyroid hormone (PTH), bone mineral content (BMC) and fracture risk differ between children of White European vs. Black African ancestry. However, randomised controlled trials (RCT) to determine the influence of vitamin D supplements on BMC and fracture risk in African children are lacking.   METHODS: We conducted a sub-study nested within a Phase 3 RCT of weekly oral supplementation with 10,000 IU vitamin D3 in Cape Town schoolchildren aged 6-11 years. Sub-study outcomes were BMC at the whole body minus head and lumbar spine sites, determined by dual-energy x-ray absorptiometry (DXA), serum concentrations of 25-hydroxyvitamin D3 (25[OH]D3), PTH, alkaline phosphatase (ALP), C-terminal telopeptide (CTX) and procollagen type 1 N propeptide (P1NP). Incidence of fractures was a secondary outcome of the main trial.   FINDINGS: 1682 children of Black African ancestry attending 23 schools were enrolled in the main trial (829 vs. 853 randomised to vitamin D vs. placebo, respectively) of whom 450 also participated in the nested sub-study (228 vs. 222 randomised to vitamin D vs. placebo, respectively). In the sub-study population, end-trial serum concentrations of 25(OH)D3 were higher for participants allocated to vitamin D vs. placebo (adjusted mean difference [aMD] 39.9 nmol/L, 95% CI 36.1 to 43.6 nmol/L, P<0.001) and serum PTH concentrations were lower (aMD -0.55 pmol/L, 95% CI -0.94 to -0.17, P=0.005). However, no interarm differences were seen for BMC at the whole body minus head (aMD -8.0 g, 95% CI -30.7 to 14.7) or the lumbar spine (aMD -0.3 g, 95% CI -1.3 to 0.8), or for serum concentrations of alkaline phosphatase, CTX or P1NP (P≥0.28). In the main trial population, allocation to vitamin D vs. placebo did not influence the proportion of participants reporting one or more fractures (adjusted odds ratio 0.70, 95% CI 0.27 to 1.85, P=0.48).   INTERPRETATION: Weekly oral supplementation with 10,000 IU vitamin D3 for 3 years elevated serum 25(OH)D3 concentrations and suppressed serum PTH concentrations among Cape Town schoolchildren of Black African ancestry but did not influence BMC, serum concentrations of bone turnover markers or fracture risk

Influence of vitamin D supplementation on bone mineral content, bone turnover markers and fracture risk in South African schoolchildren: Multicentre double-blind randomised placebo-controlled trial (ViDiKids)

Randomised controlled trials (RCT) to determine the influence of vitamin D on bone mineral content (BMC) and fracture risk in children of Black African ancestry are lacking. We conducted a sub-study (n=450) nested within a Phase 3 RCT of weekly oral supplementation with 10,000 IU vitamin D3 vs. placebo for 3 years in HIV- uninfected Cape Town schoolchildren aged 6-11 years. Outcomes were BMC at the whole body less head (WBLH) and lumbar spine (LS) and serum 25-hydroxyvitamin D3 (25[OH]D3), parathyroid hormone (PTH), alkaline phosphatase, C-terminal telopeptide and procollagen type 1 N propeptide. Incidence of fractures was a secondary outcome of the main trial (n=1682). At baseline, mean serum 25(OH)D3 concentration was 70.0 nmol/L (s.d. 13.5), and 5.8% of participants had serum 25(OH)D3 concentrations <50 nmol/L. Among sub-study participants, end-trial serum 25(OH)D3 concentrations were higher for participants allocated to vitamin D vs. placebo (adjusted mean difference [aMD] 39.9 nmol/L, 95% CI 36.1 to 43.6) and serum PTH concentrations were lower (aMD -0.55 pmol/L, 95% CI -0.94 to -0.17). However, no interarm differences were seen for WBLH BMC (aMD -8.0 g, 95% CI - 30.7 to 14.7) or LS BMC (aMD -0.3 g, 95% CI -1.3 to 0.8) or serum concentrations of bone turnover markers. Fractures were rare among participants in the main trial randomised to vitamin D vs. placebo (7/755 vs. 10/758 attending at least one follow- up; adjusted odds ratio 0.70, 95% CI 0.27 to 1.85). In conclusion, a 3-year course of weekly oral vitamin D supplementation elevated serum 25(OH)D3 concentrations and suppressed serum PTH concentrations in HIV-uninfected South African schoolchildren of Black African ancestry but did not influence BMC or serum concentrations of bone turnover markers. Fracture incidence was low, limiting power to detect an effect of vitamin D on this outcome

Towards the Human Colorectal Cancer Microbiome

Multiple factors drive the progression from healthy mucosa towards sporadic colorectal carcinomas and accumulating evidence associates intestinal bacteria with disease initiation and progression. Therefore, the aim of this study was to provide a first high-resolution map of colonic dysbiosis that is associated with human colorectal cancer (CRC). To this purpose, the microbiomes colonizing colon tumor tissue and adjacent non-malignant mucosa were compared by deep rRNA sequencing. The results revealed striking differences in microbial colonization patterns between these two sites. Although inter-individual colonization in CRC patients was variable, tumors consistently formed a niche for Coriobacteria and other proposed probiotic bacterial species, while potentially pathogenic Enterobacteria were underrepresented in tumor tissue. As the intestinal microbiota is generally stable during adult life, these findings suggest that CRC-associated physiological and metabolic changes recruit tumor-foraging commensal-like bacteria. These microbes thus have an apparent competitive advantage in the tumor microenvironment and thereby seem to replace pathogenic bacteria that may be implicated in CRC etiology. This first glimpse of the CRC microbiome provides an important step towards full understanding of the dynamic interplay between intestinal microbial ecology and sporadic CRC, which may provide important leads towards novel microbiome-related diagnostic tools and therapeutic interventions