Inviscid SPH

In smooth-particle hydrodynamics (SPH), artificial viscosity is necessary for the correct treatment of shocks, but often generates unwanted dissipation away from shocks. We present a novel method of controlling the amount of artificial viscosity, which uses the total time derivative of the velocity divergence as shock indicator and aims at completely eliminating viscosity away from shocks. We subject the new scheme to numerous tests and find that the method works at least as well as any previous technique in the strong-shock regime, but becomes virtually inviscid away from shocks, while still maintaining particle order. In particular sound waves or oscillations of gas spheres are hardly damped over many periods.Comment: 14 pages (15 in arXiv), 15 figures, accepted for publication in MNRA

Perceptions of long-term impact and change following a midwife-led biomass smoke education program for mothers in rural Uganda: a qualitative study

Introduction: Women and children in Uganda and other low- and middle-income countries are exposed to disproportionately high levels of household air pollution from biomass smoke generated by smoke-producing cookstoves, especially in rural areas. This population is therefore particularly vulnerable to the negative health effects caused by household air pollution, including negative pregnancy outcomes and other health issues throughout life. The Midwife Project, a collaboration between research and health teams in the UK and Uganda, began in 2016 to implement an education program on lung health for mothers in Uganda, to reduce the health risks to women and children. Education materials were produced to guide midwives in the delivery of health messages across four rural health centres, and mixed-methods results of knowledge questionnaires and interviews demonstrated knowledge acquisition, acceptability and feasibility. This qualitative follow-up study aimed to improve understanding of the longer term impact of this education program from the perspective of midwives, village health team members and mothers, in consideration of rolling the program out more widely in rural Uganda. Methods: Purposive sampling was carried out to recruit consenting antenatal or postnatal women, midwives and village health team members who had been involved in an education session. Individual interviews were conducted with 12 mothers and four village health team members, and four focus groups were conducted with 10 midwives in total. Interviews and focus groups were conducted across all four health centres by two researchers and six translators as appropriate depending on language spoken (English or Lusoga). These were semi-structured and directed by topic guides. Reflective and observational notes were also made. A thematic analysis was carried out by two researchers, along with production of a narrative for each mother, to enrich understanding of each individual story. Results: Midwives and village health teams had continued with the program well past the project end date and all mothers expressed making, or intending to make, changes, suggesting long-term feasibility and acceptability. Main themes generated were ability to change and changes made, ability to change dictated by money, importance of practical education, perceived health improvements, and passing on knowledge. Additional findings were that some education topics seemed to be overlooked, and there was a lack of clarity about the village health team role for the purposes of this program. Some mothers had been motivated to overcome financial barriers, for example by reconstructing cooking areas cheaply themselves. However, information given in the program about building advice and potential financial gains was inconsistent. Conclusion: Recommendations for future biomass smoke education should include explicit building advice, emphasis on financial gains, encouragement to share the knowledge acquired and clarification of the village health team role. These program changes will improve focus and relevancy, optimise impact and, with behaviour change and implementation strategy in mind, could be used for widespread rollout in rural Uganda. Future research should include quantitative data collection to objectively examine surprising perceived health benefits, including reduction in malaria and burns, and further qualitative work on why some education content appears neglected

Inserting rights and justice into urban resilience : a focus on everyday risk

Resilience building has become a growing policy agenda, particularly for urban risk management. While much of the resilience agenda has been shaped by policies and discourses from the global North, its applicability for cities of the global south, particularly African cities, has not been sufficiently assessed. Focusing on rights of urban citizens as the object to be made resilient, rather than physical and ecological infrastructures, may help to address many of the root causes that characterize the unacceptable risks that urban residents face on a daily basis. Linked to this idea, we discuss four entry points for grounding a rights and justice orientation for urban resilience. First, notions of resilience must move away from narrow, financially-orientated risk analyses. Second, opportunities must be created for “negotiated resilience”, to allow for attention to processes that support these goals, as well as for the integration of diverse interests. Third, achieving resilience in ways that do justice to the local realities of diverse urban contexts necessitates taking into account endogenous, locally situated processes, knowledges and norms. And finally, urban resilience needs to be placed within the context of global systems, providing an opportunity for African contributions to help reimagine the role that cities might play in these global finance, politics and science processes

Induction of the nicotinamide riboside kinase NAD⁺ salvage pathway in a model of sarcoplasmic reticulum dysfunction

Background Hexose-6-Phosphate Dehydrogenase (H6PD) is a generator of NADPH in the Endoplasmic/Sarcoplasmic Reticulum (ER/SR). Interaction of H6PD with 11 beta-hydroxysteroid dehydrogenase type 1 provides NADPH to support oxo-reduction of inactive to active glucocorticoids, but the wider understanding of H6PD in ER/SR NAD(P)(H) homeostasis is incomplete. Lack of H6PD results in a deteriorating skeletal myopathy, altered glucose homeostasis, ER stress and activation of the unfolded protein response. Here we further assess muscle responses to H6PD deficiency to delineate pathways that may underpin myopathy and link SR redox status to muscle wide metabolic adaptation. Methods We analysed skeletal muscle from H6PD knockout (H6PDKO), H6PD and NRK2 double knockout (DKO) and wild-type (WT) mice. H6PDKO mice were supplemented with the NAD(+) precursor nicotinamide riboside. Skeletal muscle samples were subjected to biochemical analysis including NAD(H) measurement, LC-MS based metabolomics, Western blotting, and high resolution mitochondrial respirometry. Genetic and supplement models were assessed for degree of myopathy compared to H6PDKO. Results H6PDKO skeletal muscle showed adaptations in the routes regulating nicotinamide and NAD(+) biosynthesis, with significant activation of the Nicotinamide Riboside Kinase 2 (NRK2) pathway. Associated with changes in NAD(+) biosynthesis, H6PDKO muscle had impaired mitochondrial respiratory capacity with altered mitochondrial acylcarnitine and acetyl-CoA metabolism. Boosting NAD(+) levels through the NRK2 pathway using the precursor nicotinamide riboside elevated NAD(+)/NADH but had no effect to mitigate ER stress and dysfunctional mitochondrial respiratory capacity or acetyl-CoA metabolism. Similarly, H6PDKO/NRK2 double KO mice did not display an exaggerated timing or severity of myopathy or overt change in mitochondrial metabolism despite depression of NAD(+) availability. Conclusions These findings suggest a complex metabolic response to changes in muscle SR NADP(H) redox status that result in impaired mitochondrial energy metabolism and activation of cellular NAD(+) salvage pathways. It is possible that SR can sense and signal perturbation in NAD(P)(H) that cannot be rectified in the absence of H6PD. Whether NRK2 pathway activation is a direct response to changes in SR NAD(P)(H) availability or adaptation to deficits in metabolic energy availability remains to be resolved

Type I interferon is required for T helper (Th) 2 induction by dendritic cells

Type 2 inflammation is a defining feature of infection with parasitic worms (helminths), as well as being responsible for widespread suffering in allergies. However, the precise mechanisms involved in T helper (Th) 2 polarization by dendritic cells (DCs) are currently unclear. We have identified a previously unrecognized role for type I IFN (IFN-I) in enabling this process. An IFN-I signature was evident in DCs responding to the helminth Schistosoma mansoni or the allergen house dust mite (HDM). Further, IFN-I signaling was required for optimal DC phenotypic activation in response to helminth antigen (Ag), and efficient migration to, and localization with, T cells in the draining lymph node (dLN). Importantly, DCs generated from Ifnar1-/- mice were incapable of initiating Th2 responses in vivo. These data demonstrate for the first time that the influence of IFN-I is not limited to antiviral or bacterial settings but also has a central role to play in DC initiation of Th2 responses

Accuracy and precision of a new, portable, handheld blood gas analyzer, the IRMA®

Objective. The accuracy and precision of the new IRMA® (Immediate Response Mobile Analysis System, Diametrics, Inc.®, St. Paul, MN) handheld blood gas analyzer was compared with that of two benchtop blood gas analyzers. The IRMA consists of a notebook-sized machine and disposable cartridges, each containing a pH, a CO 2 and an O 2 electrode, and provides bedside (point-of-care) blood gas analysis. Methods. A total of 172 samples (arterial and mined venous) were obtained from 25 informed, consenting patients undergoing cardiopulmonary bypass. The pH, PCO 2 and PO 2 of each sample was determined on four blood gas analyzers: NOVA Statlabs Profile 5 (NOVA Biomedical, Waltham, MA), the ABL-50 (Radiometer, West Lake, OH), and two IRMA machines. Linear regression and bias ± precision were determined, comparing each of the analyzers with the NOVA. Results. All three machines showed a similar, high degree of correlation with the NOVA for pH, PCO 2 , and PO 2 . The bias and precision of the IRMA machines compared with the NOVA was similar to that of the ABL compared with the NOVA for pH (NOVA:ABL −0.005 ± 0.011; NOVA: IRMA 1 = 0.0026 ± 0.025; NOVA: IRMA 2 = 0.0021 ± 0.025), for PCO 2 (NOVA:ABL = −1.4 ± 1.3 mmHg; NOVA: IRMA 1 = −1.3 ± 1.9 mmHg; NOVA: IRMA 2 = −1.2 ± 2.1 mmHg) and PO 2 (NOVA:ABL = 3.6 ± 21.1 mmHg; NOVA: IRMA 1 = 3.4 = 19.9 mmHg; NOVA: IRMA 2 = 6.3 ± 20.9 mmHg). The bias found for pH, PCO 2 , and PO 2 was not affected by extremes of temperature (range 25.5–40°C) or hematocrit (range 11–44%) for any machine. Conclusions. The new technology incorporated in the IRMA blood gas analyzer provides results with an accuracy that is similar to that of benchtop analyzers, but with all of the advantages of point-of-care analysis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43058/1/10877_2005_Article_BF02221753.pd

Feasibility and acceptability of a midwife-led health education strategy to reduce exposure to biomass smoke among pregnant women in Uganda, A FRESH AIR project.

Biomass smoke exposure is a threat to child and maternal health in many resource-limited countries and is associated with poor pregnancy outcomes and serious lung diseases in the offspring. We aimed to assess the feasibility, acceptability and impact of a midwife-led education programme on biomass risks and prevention for women attending maternity clinics in Uganda. Education materials were co-developed through an iterative process by midwives and other stakeholders. The materials were serially tested and approved by the Ministry of Health and used by midwives and village health teams (VHTs). The district health team, 12 midwives and 40 VHTs were sensitised on biomass smoke. Two hundred and forty-four women were educated about biomass smoke by midwives; pre- and post-session questionnaires showed major improvements in knowledge of biomass smoke risks. Qualitative interviews with women three months after the sessions showed that they made behavioural changes such as avoiding smoke while cooking, using dry wood, solar power for lighting and improved ventilation. The major barrier to behavioural changes was poverty, but some improvements cost no money. The programme delivered by midwives was feasible and acceptable; implementing this programme has the potential to reduce exposure to smoke with major benefits to mother, foetus, and children throughout their lives

Blood pressure self-monitoring in pregnancy: examining feasibility in a prospective cohort study

Background: Raised blood pressure (BP) affects approximately 10% of pregnancies worldwide, and a high proportion of affected women develop pre-eclampsia. This study aimed to evaluate the feasibility of self-monitoring of BP in pregnancy in women at higher risk of pre-eclampsia. Methods: This prospective cohort study of self-monitoring BP in pregnancy was carried out in two hospital trusts in Birmingham and Oxford and thirteen primary care practices in Oxfordshire. Eligible women were those defined by the UK National Institute for Health and Care Excellence (NICE) guidelines as at higher risk of pre-eclampsia. A total of 201 participants were recruited between 12 and 16 weeks of pregnancy and were asked to take two BP readings twice daily three times a week through their pregnancy. Primary outcomes were recruitment, retention and persistence of self-monitoring. Study recruitment and retention were analysed with descriptive statistics. Survival analysis was used to evaluate the persistence of self-monitoring and the performance of self-monitoring in the early detection of gestational hypertension, compared to clinic BP monitoring. Secondary outcomes were the mean clinic and self-monitored BP readings and the performance of self-monitoring in the detection of gestational hypertension and pre-eclampsia compared to clinic BP. Results: Of 201 women recruited, 161 (80%) remained in the study at 36 weeks or to the end of their pregnancy, 162 (81%) provided any home readings suitable for analysis, 148 (74%) continued to self-monitor at 20 weeks and 107 (66%) at 36 weeks. Self-monitored readings were similar in value to contemporaneous matched clinic readings for both systolic and diastolic BP. Of the 23 who developed gestational hypertension or pre-eclampsia and self-monitored, 9(39%) had a raised home BP prior to a raised clinic BP. Conclusions: Self-monitoring of BP in pregnancy is feasible and has potential to be useful in the early detection of gestational hypertensive disorders but maintaining self-monitoring throughout pregnancy requires support and probably enhanced training

SPH Simulations of Black Hole Accretion: A Step to Model Black Hole Feedback in Galaxies

(Abridged) We test how accurately the smoothed particle hydrodynamics (SPH) numerical technique can follow spherically-symmetric Bondi accretion. Using the 3D SPH code GADGET-3, we perform simulations of gas accretion onto a central supermassive black hole (SMBH) of mass 10^8 M_sun within the radial range of 0.1 - 200 pc. We carry out simulations without and with radiative heating by a central X-ray corona and radiative cooling. For an adiabatic case, the radial profiles of hydrodynamical properties match the Bondi solution, except near the inner and outer radius of the computational domain. We find that adiabatic Bondi accretion can be reproduced for durations of a few dynamical times at the Bondi radius, and for longer times if the outer radius is increased. With radiative heating and cooling included, the spherically accreting gas takes a longer time to reach a steady-state than the adiabatic Bondi accretion runs, and in some cases does not reach a steady-state even within several hundred dynamical times. We find that artificial viscosity in the GADGET code causes excessive heating near the inner radius, making the thermal properties of the gas inconsistent with a physical solution. This overheating occurs typically only in the supersonic part of the flow, so that it does not affect the mass accretion rate. We see that increasing the X-ray luminosity produces a lower central mass inflow rate, implying that feedback due to radiative heating is operational in our simulations. With a sufficiently high X-ray luminosity, the inflowing gas is radiatively heated up, and an outflow develops. We conclude that the SPH simulations can capture the gas dynamics needed to study radiative feedback provided artificial viscosity alters only highly supersonic part of the inflow.Comment: 25 pages, 3 tables, and 16 figures. Version accepted for publication in MNRAS. Sec. 3.1.5 extensively revised, results from new runs adde

Individual Health Trainers to support health and wellbeing for people under community supervision in the criminal justice system: the STRENGTHEN pilot RCT

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