A method of calculating compressible turbulent boundary layers

Equations of motion for calculating compressible turbulent boundary layer

Computer program for calculating laminar and turbulent boundary layer development in compressible flow

A computer program is described which performs a numerical integration of the equations of motion for a compressible two-dimensional boundary layer. Boundary layer calculations may be carried out for both laminar and turbulent flow for arbitrary Reynolds number and free stream Mach number distribution on planar or axisymmetric bodies with wall heating or cooling, longitudinal wall curvature, wall suction or blowing, and a rough or a smooth wall. A variety of options are available as initial conditions. The program can generate laminar initial conditions such as Falkner-Skan similarity solutions (so that initial wedge flows can be simulated including Blasius or stagnation point flow) or approximate equilibrium turbulent profiles. Alternatively, initial profile input data can be utilized

Charged gravitational instantons in five-dimensional Einstein-Gauss-Bonnet-Maxwell theory

We study a solution of the Einstein-Gauus-Bonnet theory in 5 dimensions coupled to a Maxwell field, whose euclidean continuation gives rise to an instanton describing black hole pair production. We also discuss the dual theory with a 3-form field coupled to gravity.Comment: 8 pages, plain Te

Subtropical Mode Water in the 137°E Section

Rotational effects on turbulence structure and mixing are investigated using a second-moment closure model. Both explicit and implicit Coriolis terms are considered. A general criterion for rotational effects to be small is established in terms of local turbulent Rossby numbers. Characteristic length scales are determined for rotational effects and Monin–Obukhov type similarity theory is developed for rotating stratified flows. A one-dimensional version of the closure model is then applied to simulate oceanic mixed layer evolution. It is shown that the effects of rotation on mixed layer depth tend to be small because of the influence of stable stratification. These findings contradict a hypothesis of Garwood et al. that rotational effects on turbulence are responsible for the disparity in the mixed-layer depths between the eastern and western regions of the equatorial Pacific Ocean. The model is also applied to neutrally stratified flows to demonstrate that rotation can either stabilize or destabilize the flow

Systematic review and meta-analysis of the prognostic significance of Neutrophil-Lymphocyte Ratio (NLR) After R0 gastrectomy for cancer

Abstract Purpose A meta-analysis was performed to evaluate the prognostic value of neutrophil-lymphocyte ratio (NLR) in patients undergoing potentially curative gastrectomy for cancer (GC). Methods Thomson Reuters Web of Science, Ovid MEDLINE(R) and PUBMED databases were searched for relevant articles using search terms neutrophil-lymphocyte ratio (NLR), GC and survival. Articles reporting overall survival (OS), cancer-specific survival and disease-free survival (DFS), in patients undergoing R0 gastrectomy, were studied. Results Articles numbering 365 were identified during the preliminary search, and 10 containing 4164 patients were included in the final review. Most patients were &gt; 60 years of age, male (67%) and 2239 (53.8%) had pT3 disease. The number of NLR dichotomization thresholds reported numbered 7, with 2.00 and 3.00 (n = 2) the most common. NLR was associated with poor survival in eight studies with hazard ratios ranging from 1.54 (95% confidence interval (CI) 1.26–1.89) to 2.99 (1.99–4.49). Pooled odds ratio (OR) for OS was 2.31 (1.40–3.83, p = 0.001) and for DFS 2.72 (1.14–6.54, p = 0.020). Four studies presented T-stage data, OR 1.62 (1.33–1.96, p &lt; 0.001). Conclusion NLR is an important prognostic indicator associated with both OS and DFS after R0 resection of GC, but the critical level is equivocal. </jats:sec

The impact of posttraumatic stress disorder on upper gastrointestinal investigations in Australian Defence Force veterans: a retrospective review

Veterans with posttraumatic stress disorder (PTSD) commonly exhibit associated gastrointestinal (GI) symptoms. We compared upper GI endoscopy and abdominal ultrasound rates in veterans with and without PTSD. Veterans with PTSD were 77–81% more likely to undergo these procedures than those without PTSD. PTSD symptomatology influences GI investigation rate and more emphasis on clinician and patient education is recommended regarding stress-related gut symptoms

Social support as protective factor of the effects of part- time work on psychological health: a moderated mediation model

Purpose:The purpose of this study is to examine the protective effect of social support on psychological health and how it differs by gender in the context of part-time employment. Design/methodology/approach: The sample consisted of 22,786 employees from four service sector organisations. Structural equation modelling was used to test a moderated mediation model assessing the relationship between employment status (part-time vs full-time) and psychological health mediated by social support (from management and colleagues) and moderated by gender. Findings: Social support from management and colleagues was associated with fewer symptoms of stress, anxiety and depression. Notably, management support had a stronger association than that of colleagues’ support on each of the three health-related variables. Social support was also found to be a mediator of part-time working on health such that lower social support led to increased health symptoms. Moreover, we found moderating gender effects between social support and psychological health such that colleague support had a stronger effect on reduced depression and stress among men than women whilst management support had a stronger effect on reduced anxiety for women. Finally, significant moderated mediating paths were found, but further research is needed to identify other potential moderators of the mediating effects. Originality/value: The findings suggest complex relationships between part-time employment, social support, psychological health and gender not examined in previous studies. It highlights the value of diverse sources of support and the necessity of addressing specific gender’s needs for enhancing psychological health of part-time employees

A sublethal concentration of Sulfoxaflor has minimal impact on buff-tailed bumblebee (Bombus terrestris) locomotor behaviour under aversive conditioning

Pesticide exposure has been cited as a key threat to insect pollinators. Notably, a diverse range of potential sublethal effects have been reported in bee species, with a particular focus on effects due to exposure to neonicotinoid insecticides. Here, a purpose-built thermal–visual arena was used in a series of pilot experiments to assess the potential impact of approximate sublethal concentrations of the next generation sulfoximine insecticide sulfoxaflor (5 and 50 ppb) and the neonicotinoid insecticides thiacloprid (500 ppb) and thiamethoxam (10 ppb), on the walking trajectory, navigation and learning abilities of the buff-tailed bumblebee (Bombus terrestris audax) when subjected to an aversive conditioning task. The results suggest that only thiamethoxam prevents forager bees from improving in key training parameters (speed and distanced travelled) within the thermal visual arena. Power law analyses further revealed that a speed–curvature power law, previously reported as being present in the walking trajectories of bumblebees, is potentially disrupted under thiamethoxam (10 ppb) exposure, but not under sulfoxaflor or thiacloprid exposure. The pilot assay described provides a novel tool with which to identify subtle sublethal pesticide impacts, and their potential causes, on forager bees, that current ecotoxicological tests are not designed to assess

Post-traumatic stress disorder is associated with a higher rate of polypectomy independent of an increased frequency of colonoscopy in Australian veterans: a retrospective review

Background Post-traumatic stress disorder (PTSD) is associated with extensive physical comorbidities, including lower gastrointestinal symptoms. Diagnostic uncertainty and poor therapeutic responses may result in more frequent colonoscopies than clinically necessary. Polypectomy is standard practice when polyps are identified, and if PTSD is a risk factor for polyp formation, one would expect a higher rate of polyp detection and removal in veterans with PTSD than those without PTSD. Aim To determine the association between PTSD and the rate of colonoscopy and polypectomy in Australian veterans. Methods Diagnostic and therapeutic colonoscopy rates in Australian male Veterans aged &gt;= 50 years were examined by reviewing case records of veterans who accessed Department of Veterans' Affairs funded health services between 1 January 2013 and 31 December 2018. Results A total of 138 471 veterans was included, of whom 28 018 had a diagnosis of PTSD; 56.4% were aged &gt;= 65 years. Twenty-one percent of the entire cohort underwent at least one colonoscopy during the study period. Increased rates of diagnostic colonoscopy and polypectomy were associated with the presence of PTSD across all age brackets. The effect was empirically large as veterans with PTSD experience colonoscopy rates 76-81% greater than those without PTSD. Similarly, veterans with PTSD experienced polypectomy rates 76-81% greater than veterans without PTSD, and this increase persisted when controlling for the increased number of diagnostic colonoscopies they undergo. Conclusion The presence of PTSD has a marked impact on colonoscopy rates in Australian veterans. The increased polypectomy rate independent of increased colonoscopy rate suggests that PTSD is a risk factor for colonic polyp formation