Significance of buoyancy in turbulence closure for computational fluid dynamics modelling of ultraviolet disinfection in maturation ponds

Buoyancy-driven turbulent dispersion in a maturation pond is studied by a combination of field measurements and computational fluid dynamics. Modelling flow in maturation ponds requires turbulent closure models because of the large physical size and the need to model on diurnal time scales. Simulation results are shown to be more sensitive to the inclusion of a buoyancy production term appearing in the turbulent transport equations than to the model choice. Comparisons with experimental thermal profiles show that without this term, thermal mixing is over predicted. When including the term, stratification occurs but thermal mixing is under-predicted in the lower water column. In terms of pond performance, the effect of this term is to cause increased surface die-off of Escherichia coli during sunlight hours due to the generation of stratification. It is recommended that future modelling consider and implement this term

Pregnancy postponement and childlessness leads to chronic hypervascularity of the breasts and cancer risk

Epidemiologists have established that women with small families, and particularly nulliparae, are prone to develop breast cancer later in life. We report that physiological mammary hypervascularity may be an intermediate reason against the background that breast-core vascularity is normal in pregnancy but pathological in the vascularisation of cancer. We examined breast ‘core’ vascularity in nulliparae during their potential reproductive life and in parous women after their last birth but before their menopause. Fifty clinically normal pre-menopausal non-pregnant women (100 breasts) were studied daily for one ‘luteal positive’ menstrual cycle. Their parity history varied from zero to five babies. Under controlled domestic conditions each wore a special electronic thermometric bra to automatically record breast ‘core’ temperature changes as a measure of mammary tissue blood flow. In the nulliparae there was a rise of breast vascularity throughout reproductive life. In the parous women, a year or so after each birth, breast vascularity was reset at a lower level than before the pregnancy; thereafter, as in nulliparae, there was progressive increase in mammary vascularity until the menopause

Reverse mathematics of matroids

Matroids generalize the familiar notion of linear dependence from linear algebra. Following a brief discussion of founding work in computability and matroids, we use the techniques of reverse mathematics to determine the logical strength of some basis theorems for matroids and enumerated matroids. Next, using Weihrauch reducibility, we relate the basis results to combinatorial choice principles and statements about vector spaces. Finally, we formalize some of the Weihrauch reductions to extract related reverse mathematics results. In particular, we show that the existence of bases for vector spaces of bounded dimension is equivalent to the induction scheme for \Sigma^0_2 formulas

Severity of maternal SARS-CoV-2 infection and perinatal outcomes of women admitted to hospital during the omicron variant dominant period using UK Obstetric Surveillance System data: prospective, national cohort study.

OBJECTIVES: To describe the severity of maternal infection when the omicron SARS-CoV-2 variant (B.1.1.529) was dominant (15 December 2021 to 14 March 2022) and describe outcomes by symptoms and vaccination status. DESIGN: Prospective, national cohort study using the UK Obstetric Surveillance System. SETTING: 94 hospitals in the UK with a consultant led maternity unit. PARTICIPANTS: Pregnant women admitted to hospital for any cause with a positive SARS-CoV-2 test. MAIN OUTCOME MEASURES: Symptomatic or asymptomatic infection, vaccination status by doses before admission, and severity of maternal infection (moderate or severe infection according to modified World Health Organization's criteria). RESULTS: Of 3699 women who were admitted to hospital, 986 (26.7%, 95% confidence interval 25.3% to 28.1%) had symptoms; of these, 144 (14.6%, 12.5% to 17.0%) had a moderate to severe infection, 99 (10.4%, 8.6% to 12.5%) of 953 received respiratory support, and 30 (3.0%, 2.1% to 4.3%) were admitted to an intensive care unit. Covid-19 specific drug treatment was given to 13 (43.3%) of the 30 women in intensive care. Four women with symptoms died (0.4%, 0.1% to 1.1%). Vaccination status was known for 845 (85.6%) women with symptoms; 489 (58.9%) were unvaccinated and only 55 (6.5%) had three doses. Moderate to severe infection was reported for 93 (19.0%) of 489 unvaccinated women with symptoms, decreasing to three (5.5%) of 55 after three doses. Among the 30 women with symptoms who were admitted to intensive care, 23 (76.7%) were unvaccinated and none had received three doses. CONCLUSION: Most women with severe covid-19 disease were unvaccinated and vaccine coverage among pregnant women admitted to hospital with SARS-CoV-2 was low. Ongoing action to prioritise and advocate for vaccine uptake in pregnancy is essential. A better understanding of the persistent low use of drug treatments is an urgent priority. TRIAL REGISTRATION: ISRCTN 40092247

The JCMT Legacy Survey of the Gould Belt: Mapping 13CO and C 18O in Orion A

The Gould Belt Legacy Survey will map star-forming regions within 500 pc, using Heterodyne Array Receiver Programme (HARP), Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and Polarimeter 2 (POL-2) on the James Clerk Maxwell Telescope (JCMT). This paper describes HARP observations of the J= 3 → 2 transitions of 13CO and C18O towards Orion A. The 15 arcsec resolution observations cover 5 pc of the Orion filament, including OMC 1 (including BN–KL and Orion bar), OMC 2/3 and OMC 4, and allow a comparative study of the molecular gas properties throughout the star-forming cloud. The filament shows a velocity gradient of ∼1 km s−1 pc−1 between OMC 1, 2 and 3, and high-velocity emission is detected in both isotopologues. The Orion Nebula and Bar have the largest masses and linewidths, and dominate the mass and energetics of the high-velocity material. Compact, spatially resolved emission from CH3CN, 13CH3OH, SO, HCOOCH3, CH3CHO and CH3OCHO is detected towards the Orion Hot Core. The cloud is warm, with a median excitation temperature of ∼24 K; the Orion Bar has the highest excitation temperature gas, at >80 K. The C18O excitation temperature correlates well with the dust temperature (to within 40 per cent). The C18O emission is optically thin, and the 13CO emission is marginally optically thick; despite its high mass, OMC 1 shows the lowest opacities. A virial analysis indicates that Orion A is too massive for thermal or turbulent support, but is consistent with a model of a filamentary cloud that is threaded by helical magnetic fields. The variation of physical conditions across the cloud is reflected in the physical characteristics of the dust cores. We find similar core properties between starless and protostellar cores, but variations in core properties with position in the filament. The OMC 1 cores have the highest velocity dispersions and masses, followed by OMC 2/3 and OMC 4. The differing fragmentation of these cores may explain why OMC 1 has formed clusters of high-mass stars, whereas OMC 4 produces fewer, predominantly low-mass stars

The first legal mortgagor: a consumer without adequate protection?

This article contends that the UK government’s attempt to create a well-functioning consumer credit market will be undermined if it fails to reform the private law framework relating to the first legal mortgage. Such agreements are governed by two distinct regulatory regimes that are founded upon very different conceptions of the mortgagor. The first, the regulation of financial services overseen by the Financial Conduct Authority, derives from public law and is founded upon a conception of the mortgagor as “consumer”. The other is land law, private law regulation implemented by the judiciary and underpinned by a conception of the mortgagor as “landowner”. Evidence suggests that the operation of these two regimes prevents mortgagors from receiving fair and consistent treatment. The current reform of financial services regulation therefore will change only one part of this governance regime and will leave mortgagors heavily reliant upon a regulator that still has to prove itself. What this article argues is that reform of the rules of private law must also be undertaken with the aim of initiating a paradigm shift in the conception of the mortgagor from “landowner” to “consumer”. Cultural shifts of this kind take time but the hope is that this conceptual transformation will occur in time to deter the predicted rise in mortgage possessions

A randomised controlled trial of cognitive behavioural treatment for obsessive compulsive disorder in children and adolescents

Cognitive behaviour therapy (CBT) for young people with obsessive compulsive disorder (OCD) has become the treatment of first choice. However, the literature is largely based on studies emphasising exposure and response prevention. In this study, we report on a randomised controlled trial of CBT for young people carried out in typical outpatient clinic conditions which focused on cognitions. A randomised controlled trial compares 10 sessions of manualised cognitive behavioural treatment with a 12-week waiting list for adolescents and children with OCD. Assessors were blind to treatment allocation. 21 consecutive patients with OCD aged between 9 and 18 years were recruited. The group who received treatment improved more than a comparison group who waited for 3 months. The second group was treated subsequently using the same protocol and made similar gains. In conclusion, CBT can be delivered effectively to young people with OCD in typical outpatient settings

Adiposity has differing associations with incident coronary heart disease and mortality in the Scottish population: cross-sectional surveys with follow-up

Objective: Investigation of the association of excess adiposity with three different outcomes: all-cause mortality, coronary heart disease (CHD) mortality and incident CHD. Design: Cross-sectional surveys linked to hospital admissions and death records. Subjects: 19 329 adults (aged 18–86 years) from a representative sample of the Scottish population. Measurements: Gender-stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause mortality, CHD mortality and incident CHD. Separate models incorporating the anthropometric measurements body mass index (BMI), waist circumference (WC) or waist–hip ratio (WHR) were created adjusted for age, year of survey, smoking status and alcohol consumption. Results: For both genders, BMI-defined obesity (greater than or equal to30 kg m−2) was not associated with either an increased risk of all-cause mortality or CHD mortality. However, there was an increased risk of incident CHD among the obese men (hazard ratio (HR)=1.78; 95% confidence interval=1.37–2.31) and obese women (HR=1.93; 95% confidence interval=1.44–2.59). There was a similar pattern for WC with regard to the three outcomes; for incident CHD, the HR=1.70 (1.35–2.14) for men and 1.71 (1.28–2.29) for women in the highest WC category (men greater than or equal to102 cm, women greater than or equal to88 cm), synonymous with abdominal obesity. For men, the highest category of WHR (greater than or equal to1.0) was associated with an increased risk of all-cause mortality (1.29; 1.04–1.60) and incident CHD (1.55; 1.19–2.01). Among women with a high WHR (greater than or equal to0.85) there was an increased risk of all outcomes: all-cause mortality (1.56; 1.26–1.94), CHD mortality (2.49; 1.36–4.56) and incident CHD (1.76; 1.31–2.38). Conclusions: In this study excess adiposity was associated with an increased risk of incident CHD but not necessarily death. One possibility is that modern medical intervention has contributed to improved survival of first CHD events. The future health burden of increased obesity levels may manifest as an increase in the prevalence of individuals living with CHD and its consequences

The semantics of untrustworthiness

We offer a formal treatment of the semantics of both complete and incomplete mistrustful or distrustful information transmissions. The semantics of such relations is analysed in view of rules that define the behaviour of a receiving agent. We justify this approach in view of human agent communications and secure system design. We further specify some properties of such relations