Code optimisation in a nested-sampling algorithm

The speed-up in program running time is investigated for problems of parameter estimation with Nested Sampling Monte Carlo methods. The example used in this study is to extract a polarization observable from event-by-event data from meson photoproduction reactions. Various implementations of the basic algorithm were compared, consisting of combinations of single threaded vs multi-threaded, and CPU vs GPU versions. These were implemented in OpenMP and OpenCL. For the application under study, and with the number of events as used in our work, we find that straightforward multi-threaded CPU OpenMP coding gives the best performance; for larger numbers of events, OpenCL on the CPU performs better. The study also shows that there is a “break-even” point of the number of events where the use of GPUs helps performance. GPUs are not found to be generally helpful for this problem, due to the data transfer times, which more than offset the improvement in computation time

The nucleon's strange electromagnetic and scalar matrix elements

Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on strange quark mass, valence quark mass and momentum transfer are discussed in both the lattice and chiral frameworks. The combined results of this study are in good agreement with existing experimental data and predictions are made for upcoming experiments. Possible future refinements of the theoretical method are suggested.Comment: 24 pages, 9 figure

Whole egg consumption and cortical bone in healthy children

Eggs contain bioactive compounds thought to benefit pediatric bone. This cross-sectional study shows a positive link between childhood egg intake and radius cortical bone. If randomized trials confirm our findings, incorporating eggs into children's diets could have a significant impact in preventing childhood fractures and reducing the risk of osteoporosis. INTRODUCTION: This study examined the relationships between egg consumption and cortical bone in children. METHODS: The cross-sectional study design included 294 9-13-year-old black and white males and females. Three-day diet records determined daily egg consumption. Peripheral quantitative computed tomography measured radius and tibia cortical bone. Body composition and biomarkers of bone turnover were assessed using dual-energy X-ray absorptiometry and ELISA, respectively. RESULTS: Egg intake was positively correlated with radius and tibia cortical bone mineral content (Ct.BMC), total bone area, cortical area, cortical thickness, periosteal circumference, and polar strength strain index in unadjusted models (r = 0.144-0.224, all P < 0.050). After adjusting for differences in race, sex, maturation, fat-free soft tissue mass (FFST), and protein intakes, tibia relationships were nullified; however, egg intake remained positively correlated with radius Ct.BMC (r = 0.138, P = 0.031). Egg intake positively correlated with total body bone mineral density, BMC, and bone area in the unadjusted models only (r = 0.119-0.224; all P < 0.050). After adjusting for covariates, egg intake was a positive predictor of radius FFST (β = 0.113, P < 0.050) and FFST was a positive predictor of Ct.BMC (β = 0.556, P < 0.050) in path analyses. There was a direct influence of egg on radius Ct.BMC (β = 0.099, P = 0.035), even after adjusting for the mediator, FFST (β = 0.137, P = 0.020). Egg intake was positively correlated with osteocalcin in both the unadjusted (P = 0.005) and adjusted (P = 0.049) models. CONCLUSION: If the positive influence of eggs on Ct.BMC observed in this study is confirmed through future randomized controlled trials, whole eggs may represent a viable strategy to promote pediatric bone development and prevent fractures

Parenting stress, maternal depression and child mental health in a Melbourne cohort before and during the COVID‐19 pandemic

Aim This paper aims to examine the maternal and child mental health and parenting outcomes in the context of COVID-19 pandemic conditions using a sample from Melbourne, Australia – a city exposed to one of the longest lockdowns world-wide in response to the pandemic. Methods This study utilises observational data from a prospective, pregnancy cohort, Mercy Pregnancy Emotional Wellbeing Study and includes 468 women and their children followed up in Melbourne to 3–4 years postpartum pre-COVID pandemic and compared to those followed up during the COVID-19 pandemic. Results When compared to mothers followed up at 3–4 years postpartum pre-pandemic, those followed up during the COVID-19 pandemic showed higher depressive symptoms with a steep incline in their symptom trajectory (EMMdifference = 1.72, Bonferroni-corrected P < 0.01, d = 0.35) and had a three times higher risk of scoring 13 or above on the EPDS (aRR = 3.22, Bonferroni-corrected P < 0.01). Although this increase was not associated with the variation in the duration of exposure to pandemic conditions, the steep increase in depressive symptoms was more pronounced in those with pre-existing depressive disorders. There was no difference in parenting stress or adjusted childhood mental health symptoms or disorder. Conclusions Our findings highlight the vulnerability of those with pre-existing clinical mental health disorders and the need for adequate clinical care for this vulnerable group. Equally, our study indicates the possibility that parenting and early childhood mental health outcomes, at least in the short term, may be resilient

Beetroot Juice Does Not Enhance Altitude Running Performance in Well-Trained Athletes

We hypothesized that acute dietary nitrate (NO3-) provided as concentrated beetroot juice supplement would improve endurance running performance of well-trained runners in normobaric hypoxia. Ten male runners (mean (SD): sea level V�O2max 66 (7) mL.kg^-1.min^-1, 10 km personal best 36 (2) min) completed incremental exercise to exhaustion at 4000 m and a 10 km treadmill time trial at 2500 m simulated altitude on separate days, after supplementation with ~7 mmol NO3- and a placebo, 2.5 h before exercise. Oxygen cost, arterial oxygen saturation, heart rate and ratings of perceived exertion (RPE) were determined during the incremental exercise test. Differences between treatments were determined using means [95% confidence intervals], paired sample t-tests and a probability of individual response analysis. NO3- supplementation increased plasma [nitrite] (NO3-, 473 (226) nM vs. placebo, 61 (37) nM, P < 0.001) but did not alter time to exhaustion during the incremental test (NO3-, 402 (80) s vs. placebo 393 (62) s, P = 0.5) or time to complete the 10 km time trial (NO3-, 2862 (233) s vs. placebo, 2874 (265) s, P = 0.6). Further, no practically meaningful beneficial effect on time trial performance was observed as the 11 [-60 to 38] s improvement was less than the a priori determined minimum important difference (51 s), and only three runners experienced a ´likely, probable´ performance improvement. NO3- also did not alter oxygen cost, arterial oxygen saturation, heart rate or RPE. Acute dietary NO3- supplementation did not consistently enhance running performance of well-trained athletes in normobaric hypoxia

The Mars Climate Database

The Mars Climate Database (MCD) [1] is a database of statistics describing the climate and environment of the Martian atmosphere. It was constructed directly on the basis of output from mulitannual integrations of two general circulation models (GCMs)developed by Laboratoire de Météorologie Dynamique du CNRS, France, the University of Oxford, UK, and Instituto de Astrofisica de Andalucia, Spain, with support from the European Space Agency (ESA) and Centre National d–Etudes Spatiales (CNES). A description of the MCD is given along with a comparison between spacecraft observations of Mars and results predicted at similar locations and times in the MCD. The MCD can be used as a tool for mission planning and has been applied to prepare for several missions in Europe and the USA. It also provides information for mission design specialists on the mean state and variability of the Martian environment from the surface to above 120km. The GCMs on which the database is founded, include a set of physical parameterizations (radiative transfer in the visible and thermal infrared ranges, turbulent mixing, condensation-sublimation of CO2, thermal conduction in the soil and representation of gravity waves) and two different codes for the representation of large scale dynamics: a spectral code for the AOPP version and a grid-point code for the LMD version. The GCMs correctly reproduce the main meteorological features of Mars, as observed by the Mariner 9 and Viking orbiters, the Viking landers, and Mars Global Surveyor (MGS). As well as the standard statistical measures for mission design studies, the MCD includes a novel representation of large-scale variability, using empirical eigenfunctions derived from an analysis of the full simulations, and small-scale variability based on parameterizations of processes such as gravity wave propagation. The database allows the user to choose from 5 dust storm scenarios including a best guess, default scenario, deduced from recent MGS observations, an upper boundary for an atmosphere without dust storms, as observed by Viking the landers, and a clear, cold, lower boundary scenario, as observed by Phobos 2 and from Earth. The full version of the MCD is available on CDROM (for UNIX systems and PCs) and is also accessible through an interactive WWW interface at http://www-mars.lmd.jussieu.fr/

Morphological parametric mapping of 21 skin sites throughout the body using optical coherence tomography

Background Changes in body posture cause changes in morphological properties at different skin sites. Although previous studies have reported the thickness of the skin, the details of the postures are not generally given. This paper presents the effect of a change in posture on parameters such as thickness and surface roughness in 21 load-bearing and non-load-bearing sites. Materials and methods A total of 12 volunteers (8 males and 4 females) were selected in an age group of 18–35 years and of Fitzpatrick skin type I-III. Images were captured using a clinically-approved VivoSight® optical coherence tomography system and analysed using an algorithm provided by Michelson Diagnostics. Results Overextension (extending joints to full capacity) resulted in changes to thickness, roughness and undulation of the skin around the body. Discussion and conclusion The load-bearing regions have thicker skin compared to non-load-bearing sites. This is the first time that undulation topography of the stratum corneum–stratum lucidum and the dermal–epidermal junction layers have been measured and reported using statistical values such as Ra. The data presented could help to define new skin layer models and to determine the variability of the skin around the body and between participants

Rurality as a predictor of perinatal mental health and well‐being in an Australian cohort

Objective Perinatal emotional well-being is more than the presence or absence of depressive and anxiety disorders; it encompasses a wide range of factors that contribute to emotional well-being. This study compares perinatal well-being between women living in metropolitan and rural regions. Design Prospective, longitudinal cohort. Participants/setting Eight hundred and six women from Victoria and Western Australia recruited before 20 weeks of pregnancy and followed up to 12 months postpartum. Main outcome measures Rurality was assessed using the Modified Monash Model (MM Model) with 578 in metropolitan cities MM1, 185 in regional and large rural towns MM2-MM3 and 43 in rural to remote MM4-MM7. The Structured Clinical Interview for DSM-IV (SCID-IV) was administered at recruitment to assess depression, and symptoms of depression and anxiety were measured using the Edinburgh Post-natal Depression Scale and the State and Trait Anxiety Scale, respectively. Other measures included stressful events, diet, exercise, partner support, parenting and sleep. Results The prevalence of depressive disorders did not differ across rurality. There was also no difference in breastfeeding cessation, exercise, sleep or partner support. Women living in rural communities and who also had depression reported significantly higher parenting stress than metropolitan women and lower access to parenting activities. Conclusions Our study suggests while many of the challenges of the perinatal period were shared between women in all areas, there were important differences in parenting stress and access to activities. Furthermore, these findings suggest that guidelines and interventions designed for perinatal mental health should consider rurality

A review of X-ray laser development at Rutherford Appleton Laboratory

Recent experiments undertaken at the Rutherford Appleton Laboratory to produce X-ray lasing over the 5-30 nm wavelength range are reviewed. The efficiency of lasing is optimized when the main pumping pulse interacts with a preformed plasma. Experiments using double 75-ps pulses and picosecond pulses superimposed on 300-ps background pulses are described. The use of travelling wave pumping with the approximately picosecond pulse experiments is necessary as the gain duration becomes comparable to the time for the X-ray laser pulse to propagate along the target length. Results from a model taking account of laser saturation and deviations from the speed of light c of the travelling wave and X-ray laser group velocity are presented. We show that X-ray laser pulses as short as 2-3 ps can be produced with optical pumping pulses of approximate to1-ps

Optimal surgical care for adolescent idiopathic scoliosis: an international consensus

Purpose The surgical management of adolescent idiopathic scoliosis (AIS) has seen many developments in the last two decades. Little high-level evidence is available to support these changes and guide treatment. This study aimed to identify optimal operative care for adolescents with AIS curves between 40° and 90° Cobb angle. Methods From July 2012 to April 2013, the AOSpine Knowledge Forum Deformity performed a modified Delphi survey where current expert opinion from 48 experienced deformity surgeons, representing 29 diverse countries, was gathered. Four rounds were performed: three web-based surveys and a final face-to-face meeting. Consensus was achieved with ≥70 % agreement. Data were analyzed qualitatively and quantitatively. Results Consensus of what constitutes optimal care was reached on greater than 60 aspects including: preoperative radiographs; posterior as opposed to anterior (endoscopic) surgical approaches; use of intraoperative spinal cord monitoring; use of local autologous bone (not iliac crest) for grafts; use of thoracic and lumbar pedicle screws; use of titanium anchor points; implant density of <80 % for 40°–70° curves; and aspects of postoperative care. Variability in practice patterns was found where there was no consensus. In addition, there was consensus on what does not constitute optimal care, including: routine pre- and intraoperative traction; routine anterior release; use of bone morphogenetic proteins; and routine postoperative CT scanning. Conclusions International consensus was found on many aspects of what does and does not constitute optimal operative care for adolescents with AIS. In the absence of current high-level evidence, at present, these expert opinion findings will aid health care providers worldwide define appropriate care in their regions. Areas with no consensus provide excellent insight and priorities for future researchpublished_or_final_versio