Neutral B-meson mixing from three-flavor lattice QCD: Determination of the SU(3)-breaking ratio \xi

We study SU(3)-breaking effects in the neutral B_d-\bar B_d and B_s-\bar B_s systems with unquenched N_f=2+1 lattice QCD. We calculate the relevant matrix elements on the MILC collaboration's gauge configurations with asqtad-improved staggered sea quarks. For the valence light-quarks (u, d, and s) we use the asqtad action, while for b quarks we use the Fermilab action. We obtain \xi=f_{B_s}\sqrt{B_{B_s}}/f_{B_d}\sqrt{B_{B_d}}=1.268+-0.063. We also present results for the ratio of bag parameters B_{B_s}/B_{B_d} and the ratio of CKM matrix elements |V_{td}|/|V_{ts}|. Although we focus on the calculation of \xi, the strategy and techniques described here will be employed in future extended studies of the B mixing parameters \Delta M_{d,s} and \Delta\Gamma_{d,s} in the Standard Model and beyond.Comment: 36 pages, 7 figure

Health screening clinic to reduce absenteeism and presenteeism among NHS Staff:eTHOS a pilot RCT

BackgroundStaff sickness absenteeism and presenteeism (attending work while unwell) incur high costs to the NHS, are associated with adverse patient outcomes and have been exacerbated by the COVID-19 pandemic. The main causes are mental and musculoskeletal ill health with cardiovascular risk factors common.ObjectivesTo undertake a feasibility study to inform the design of a definitive randomised controlled trial of the effectiveness and cost effectiveness of a health screening clinic in reducing absenteeism and presenteeism amongst the National Health Service staff.DesignIndividually randomised controlled pilot trial of the staff health screening clinic compared with usual care, including qualitative process evaluation.SettingFour United Kingdom National Health Service hospitals from two urban and one rural Trust.ParticipantsHospital employees who had not previously attended a pilot health screening clinic at Queen Elizabeth Hospital Birmingham.InterventionsNurse-led staff health screening clinic with assessment for musculoskeletal health (STarT musculoskeletal; STarT Back), mental health (patient health questionnaire-9; generalised anxiety disorder questionnaire-7) and cardiovascular health (NHS health check if aged ≥ 40, lifestyle check if < 40 years). Screen positives were given advice and/or referral to services according to UK guidelines.Main outcome measuresThe three coprimary outcomes were recruitment, referrals and attendance at referred services. These formed stop/go criteria when considered together. If any of these values fell into the ‘amber’ zone, then the trial would require modifications to proceed to full trial. If all were ‘red’, then the trial would be considered unfeasible.Secondary outcomes collected to inform the design of the definitive randomised controlled trial included: generalisability, screening results, individual referrals required/attended, health behaviours, acceptability/feasibility of processes, indication of contamination and costs. Outcomes related to the definitive trial included self-reported and employee records of absenteeism with reasons. Process evaluation included interviews with participants, intervention delivery staff and service providers. Descriptive statistics were presented and framework analysis conducted for qualitative data. Due to the COVID-19 pandemic, outcomes were captured up to 6 months only.ResultsThree hundred and fourteen participants were consented (236 randomised), the majority within 4 months. The recruitment rate of 314/3788 (8.3%) invited was lower than anticipated (meeting red for this criteria), but screening identified that 57/118 (48.3%) randomised were eligible for referral to either general practitioner (81%), mental health (18%) and/or physiotherapy services (30%) (green). Early trial closure precluded determination of attendance at referrals, but 31.6% of those eligible reported intending to attend (amber).Fifty-one of the 80 (63.75%) planned qualitative interviews were conducted. Quantitative and qualitative data from the process evaluation indicated that the electronic database-driven screening intervention and data collection were efficient, promoting good fidelity, although needing more personalisation at times. Recruitment and delivery of the full trial would benefit from a longer development period to better understand local context, develop effective strategies for engaging with underserved groups, provide longer training and better integration with referral services.Delivery of the pilot was limited by the impact of COVID-19 with staff redeployment, COVID-research prioritisation and reduced availability of community and in-house referral services. While recruitment was rapid, it did not fully represent ethnic minority groups and truncated follow-up due to funding limitations prevented full assessment of attendance at recommended services and secondary outcomes.ConclusionsThere is both a clinical need (evidenced by 48% screened eligible for a referral) and perceived benefit (data from the qualitative interviews) for this National Health Service staff health screening clinic. The three stop/go criteria were red, green and amber; therefore, the Trial Oversight Committee recommended that a full-scale trial should proceed, but with modifications to adapt to local context and adopt processes to engage better with underserved communities

Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke

Genetic factors have been implicated in stroke risk but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) in ischemic stroke and its subtypes in 3,548 cases and 5,972 controls, all of European ancestry. Replication of potential signals was performed in 5,859 cases and 6,281 controls. We replicated reported associations between variants close to PITX2 and ZFHX3 with cardioembolic stroke, and a 9p21 locus with large vessel stroke. We identified a novel association for a SNP within the histone deacetylase 9(HDAC9) gene on chromosome 7p21.1 which was associated with large vessel stroke including additional replication in a further 735 cases and 28583 controls (rs11984041, combined P = 1.87×10−11, OR=1.42 (95% CI) 1.28-1.57). All four loci exhibit evidence for heterogeneity of effect across the stroke subtypes, with some, and possibly all, affecting risk for only one subtype. This suggests differing genetic architectures for different stroke subtypes

VEGF-A165b is an endogenous neuroprotective splice isoform of vascular endothelial growth factor A in vivo and in vitro

Vascular endothelial growth factor (VEGF) A is generated as two isoform families by alternative RNA splicing, represented by VEGF-A165a and VEGF-A165b. These isoforms have opposing actions on vascular permeability, angiogenesis, and vasodilatation. The proangiogenic VEGF-A165a isoform is neuroprotective in hippocampal, dorsal root ganglia, and retinal neurons, but its propermeability, vasodilatatory, and angiogenic properties limit its therapeutic usefulness. In contrast, a neuroprotective effect of endogenous VEGF-A165b on neurons would be advantageous for neurodegenerative pathologies. Endogenous expression of human and rat VEGF-A165b was detected in hippocampal and cortical neurons. VEGF-A165b formed a significant proportion of total VEGF-A in rat brain. Recombinant human VEGF-A165b exerted neuroprotective effects in response to multiple insults, including glutamatergic excitotoxicity in hippocampal neurons, chemotherapy-induced cytotoxicity of dorsal root ganglion neurons, and retinal ganglion cells (RGCs) in rat retinal ischemia-reperfusion injury in vivo. Neuroprotection was dependent on VEGFR2 and MEK1/2 activation but not on p38 or phosphatidylinositol 3-kinase activation. Recombinant human VEGF-A165b is a neuroprotective agent that effectively protects both peripheral and central neurons in vivo and in vitro through VEGFR2, MEK1/2, and inhibition of caspase-3 induction. VEGF-A165b may be therapeutically useful for pathologies that involve neuronal damage, including hippocampal neurodegeneration, glaucoma diabetic retinopathy, and peripheral neuropathy. The endogenous nature of VEGF-A165b expression suggests that non-isoform-specific inhibition of VEGF-A (for antiangiogenic reasons) may be damaging to retinal and sensory neurons

Does hyperthermia constrain flight duration in a short-distance migrant?

While some migratory birds perform non-stop flights of over 11 000 km, many species only spend around 15% of the day in flight during migration, posing a question as to why flight times for many species are so short. Here, we test the idea that hyperthermia might constrain flight duration (FD) in a short-distance migrant using remote biologging technology to measure heart rate, hydrostatic pressure and body temperature in 19 migrating eider ducks (Somateria mollissima), a short-distance migrant. Our results reveal a stop-and-go migration strategy where migratory flights were frequent (14 flights day(−1)) and short (15.7 min), together with the fact that body temperature increases by 1°C, on average, during such flights, which equates to a rate of heat storage index (HSI) of 4°C h(−1). Furthermore, we could not find any evidence that short flights were limited by heart rate, together with the fact that the numerous stops could not be explained by the need to feed, as the frequency of dives and the time spent feeding were comparatively small during the migratory period. We thus conclude that hyperthermia appears to be the predominant determinant of the observed migration strategy, and suggest that such a physiological limitation to FD may also occur in other species. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’

Cryogenic Optical Performance of a Lightweighted Mirror Assembly for Future Space Astronomical Telescopes: Correlating Optical Test Results and Thermal Optical Model

A 43cm diameter stacked core mirror demonstrator was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two CNC pocket milled face sheets. The 93% lightweighted Corning ULE mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model

Cryogenic Optical Performance of a Light-weight Mirror Assembly for Future Space Astronomical Telescopes: Optical Test Results and Thermal Optical Model

A 40 cm diameter mirror assembly was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5 m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two face sheets. The 93% lightweighted Corning ULE mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model