Debris flow dynamics: A flume study of velocity and superelevation

Debris flows are powerful, geophysical flows with the potential to cause fatalities and damage infrastructure. The hazard posed by these events is often related to the velocity of the flow. However, due to their spontaneous nature and rapid onset, opportunities to observe debris flows are rare. The aim of this investigation was to improve the understanding of debris flow dynamics in curved channels using a hardware laboratory flume model. The purpose-built, variable slope, 8 m long flume enables a variety of debris flow boundary conditions to be studied. Here, 60 experimental tests were carried out at four slope of – 15°, 17°, 23° and 25°; for both straight (12 tests) and curved channels (48 tests). The modular construction of the flume enabled purpose-made channel curves to be inserted in the straight channel. Four channel bends with differing geometries were tested; three radii of curvature – 0.4, 0.55 and 0.7 m (for a bend angle of 40°) and one radius of curvature of 0.7 m for a 20° bend angle. For all runs the grain-size of the debris flow mixture consisted of a poorly sorted gravel/sand/clay mix (bulk density 1880 kg m-3, water content 17%). A combination of direct and video-based observations were used to record debris flow behaviour including variation in superelevation and the average and local velocity of the flow. Channel gradient is shown to be an important factor in controlling debris flow velocity. The straight channel results demonstrate a strong linear relationship between debris flow velocity and channel gradient. Modelling debris flow hydraulics reveals a power-law relationship, suggesting Newtonian turbulent flow conditions. The magnitude of superelevation was strongly linked to debris flow velocity, radius of curvature and bend angle. Superelevation was shown to increase in a power law relationship with debris flow velocity, which was greatest for tighter bend geometries. A decrease in radius of curvature resulted in a non-linear increase in superelevation, while decreasing the bend angle promoted a decrease in superelevation. When compared to observed superelevation, predicted values from the superelevation equation can substantially overestimate by up to 210% in some circumstances, suggesting that predicted values and back-calculated velocity estimates should be regarded as maxima. Furthermore, calculation of ‘k’ from experimental data suggests that ‘k’ was not constant (varying by two-fold) and has a value less than ‘1’, contrary to the proposed theory. This novel investigation has studied the influence of debris flow velocity, radius of curvature and bend angle upon superelevation, broadening the very limited knowledge base surrounding debris flow superelevation and its controls. For future studies it is recommended to: increase the number of experimental runs for each channel configuration; use a wider range of radii of curvature and bend angles; and improve the accuracy of the superelevation equation by introducing a parameter to account for bend angle, and to better define the significance and value of ‘k’

Situation awareness: when nurses decide to admit or not admit a person with mental illness as an involuntary patient

Aim This paper will explore the application of situation awareness in nursing to determine its suitability as a framework to study how the decision to admit or not admit a person as an involuntary patient is made. Background The decision by a specially qualified nurse to admit or not admit a person to a mental health facility against their will remains a central component of contemporary mental health legislation. The decision has an impact on a person\u27s autonomy and human rights. Conversely, the decision to admit may facilitate urgent assessment and treatment and ensure the safety of the individual and others. Research highlights that decision-making in this context is challenging due to the multiple information sources and often incomplete information available to the clinician. Situation awareness is a concept used to explain how practitioners identify, use and make meaning of a multitude of factors and elements relevant to their practice. Design Discussion paper. Data sources A search of terms related to situation awareness and mental health nursing was conducted in the period 2000 - present. Implications for nursing Exploring nurses decision-making using a situation awareness framework provides for a more nuanced understanding of nurses knowledge and skill when deciding to admit or not a person as an involuntary patient. Conclusion The concept of situation awareness provides a framework to better understand the decision-making process associated with the involuntary admission decision

Sustainable domesticity

Piece in group exhibition called 'morada ecológica'/'razão e ambiente'

Concentric and eccentric remodelling of the left ventricle and its association to function in the male athletes heart:an exploratory study

Aims: To compare (1) conventional left ventricular (LV) functional parameters, (2) LV peak strain and strain rate and (3) LV temporal strain and strain rate curves in age, ethnicity and sport-matched athletes with concentric, eccentric and normal LV geometry. Methods: Forty-five male athletes were categorised according to LV geometry including concentric remodelling/hypertrophy (CON), eccentric hypertrophy (ECC) or normal (NORM). Athletes were evaluated using conventional echocardiography and myocardial speck tracking, allowing the assessment of myocardial strain and strain rate; as well as twist mechanics. Results: Concentric remodelling was associated with an increased ejection fraction (EF) compared to normal geometry athletes (64% (48–78%) and 56% (50–65%), respectively; p < 0.04). No differences in peak myocardial strain or strain rate were present between LV geometry groups including global longitudinal strain (GLS; CON −16.9% (−14.9–20.6%); ECC −17.9% (−13.0–22.1%); NORM −16.9% (−12.8–19.4%)), global circumferential strain (GCS; CON −18.1% (−13.5–24.5%); ECC −18.7% (−15.6–22.4%); NORM −18.0% (−13.5–19.7%)), global radial strain (GRS; CON 42.2% (30.3–70.5%); ECC 50.0% (39.2–60.0%); NORM 40.6 (29.9–57.0%)) and twist (CON 14.9° (3.7–25.3°); ECC 12.5° (6.3–20.8°); NORM 13.2° (8.8–24.2°)). Concentric and eccentric remodelling was associated with alterations in temporal myocardial strain and strain rate as compared to normal geometry athletes. Conclusion: Physiological concentric and eccentric remodelling in the athletes heart is generally associated with normal LV function; with concentric remodelling associated with an increased EF. Physiological concentric and eccentric remodelling in the athletes heart has no effect on peak myocardial strain but superior deformation and untwisting is unmasked when assessing the temporal distribution

A Sm(II)-mediated cascade approach to Dibenzoindolo[3,2-b]carbazoles:synthesis and evaluation

Previously unstudied dibenzoindolo[3,2-b]carbazoles have been prepared by two-directional, phase tag-assisted synthesis utilizing a connective-Pummerer cyclization and a SmI2-mediated tag cleavage-cyclization cascade. The use of a phase tag allows us to exploit unstable intermediates that would otherwise need to be avoided. The novel materials were characterized by X-ray, cyclic voltammetry, UV-vis spectroscopy, TGA, and DSC. Preliminary studies on the performance of OFET devices are also described

Systematic review estimating the burden of dementia in the WHO Southeast Asia Region using Bayesian and frequentist approaches

Background: Rapid increase in life expectancy in low- and middle-income countries including the World Health Organization's Southeast Asia Region (SEAR) has resulted in an increase in the global burden of dementia, which is expected to become a leading cause of morbidity. Accurate burden estimates are key for informing policy and planning. Given the paucity of data, estimates were developed using both a Bayesian methodology and as well as a traditional frequentist approach to gain better insights into methodological approaches for disease burden estimates. Methods: Seven databases were searched for studies published between 2010-2018 regarding dementia prevalence in SEAR, generating 8 relevant articles. A random-effects model (REM) and a Bayesian normal-normal hierarchical model (NNHM) were used to obtain the pooled prevalence estimate of dementia for people aged 60 and above in SEAR. The latter model was also developed to estimate age-specific dementia prevalence. Using UN population estimates for SEAR, total and age-specific projections of the burden of dementia in 2015, 2020 and 2030 were calculated. Results: The prevalence of dementia in SEAR was found to be 3% (95% confidence interval (CI) = 2-6%) in those above age 60 based on REM, and 3.1% (95% credible interval = 1.5-5.0%) based on the NNHM. The estimated prevalence varies with age, increasing from 1.6% (95% credible interval = 0.8-2.5%) in people aged 60-69 to 12.4% (95% credible interval = 5.6-20%) in people above the age of 80. The risk of developing dementia increased exponentially with age. The number of people living with dementia in SEAR in 2015 was estimated at 5.51 million (95% credible interval = 2.66-8.82), with projections of 6.66 million (95% credible interval = 3.21-10.7) in 2020 and 9.6 million (95% credible interval = 4.62-15.36) in 2030. Conclusion: The burden of dementia in SEAR is substantial and will continue to increase rapidly by 2030. The lack of research focusing on dementia in SEAR points to a significant under-recognition of this disease. The projected rise in dementia cases in the future should prompt urgent governmental response to address this growing public health issue. We also argue that given the overall paucity of data for the region, the Bayesian approach offers a promising methodology for improved estimates of disease prevalence and burden and should continue to be explored

Longitudinal impact of changes in the residential built environment on physical activity: findings from the ENABLE London cohort study.

BACKGROUND: Previous research has reported associations between features of the residential built environment and physical activity but these studies have mainly been cross-sectional, limiting inference. This paper examines whether changes in a range of residential built environment features are associated with changes in measures of physical activity in adults. It also explores whether observed effects are moderated by socio-economic status. METHODS: Data from the Examining Neighbourhood Activity in Built Living Environments in London (ENABLE London) study were used. A cohort of 1278 adults seeking to move into social, intermediate, and market-rent East Village accommodation was recruited in 2013-2015, and followed up after 2 years. Accelerometer-derived steps (primary outcome), and GIS-derived measures of residential walkability, park proximity and public transport accessibility were obtained both at baseline and follow-up. Daily steps at follow-up were regressed on daily steps at baseline, change in built environment exposures and confounding variables using multilevel linear regression to assess if changes in neighbourhood walkability, park proximity and public transport accessibility were associated with changes in daily steps. We also explored whether observed effects were moderated by housing tenure as a marker of socio-economic status. RESULTS: Between baseline and follow-up, participants experienced a 1.4 unit (95%CI 1.2,1.6) increase in neighbourhood walkability; a 270 m (95%CI 232,307) decrease in distance to their nearest park; and a 0.7 point (95% CI 0.6,0.9) increase in accessibility to public transport. A 1 s.d. increase in neighbourhood walkability was associated with an increase of 302 (95%CI 110,494) daily steps. A 1 s.d. increase in accessibility to public transport was not associated with any change in steps overall, but was associated with a decrease in daily steps amongst social housing seekers (- 295 steps (95%CI - 595, 3), and an increase in daily steps for market-rent housing seekers (410 95%CI -191, 1010) (P-value for effect modification = 0.03). CONCLUSION: Targeted changes in the residential built environment may result in increases in physical activity levels. However, the effect of improved accessibility to public transport may not be equitable, showing greater benefit to the more advantaged

Collider constraints on electroweakinos in the presence of a light gravitino

Using the GAMBIT global fitting framework, we constrain the MSSM with an eV-scale gravitino as the lightest supersymmetric particle, and the six electroweakinos (neutralinos and charginos) as the only other light new states. We combine 15 ATLAS and 12 CMS searches at 13 TeV, along with a large collection of ATLAS and CMS measurements of Standard Model signatures. This model, which we refer to as the G~-EWMSSM, exhibits quite varied collider phenomenology due to its many permitted electroweakino production processes and decay modes. Characteristic G~-EWMSSM signal events have two or more Standard Model bosons and missing energy due to the escaping gravitinos. While much of the G~-EWMSSM parameter space is excluded, we find several viable parameter regions that predict phenomenologically rich scenarios with multiple neutralinos and charginos within the kinematic reach of the LHC during Run 3, or the High Luminosity LHC. In particular, we identify scenarios with Higgsino-dominated electroweakinos as light as 140 GeV that are consistent with our combined set of collider searches and measurements. The full set of G~-EWMSSM parameter samples and GAMBIT input files generated for this work is available via Zenodo

Delineating associations of progressive pleuroparenchymal fibroelastosis in patients with pulmonary fibrosis

BACKGROUND: Computer quantification of baseline computed tomography (CT) radiological pleuroparenchymal fibroelastosis (PPFE) associates with mortality in idiopathic pulmonary fibrosis (IPF). We examined mortality associations of longitudinal change in computer-quantified PPFE-like lesions in IPF and fibrotic hypersensitivity pneumonitis (FHP). METHODS: Two CT scans 6-36 months apart were retrospectively examined in one IPF (n=414) and one FHP population (n=98). Annualised change in computerised upper-zone pleural surface area comprising radiological PPFE-like lesions (Δ-PPFE) was calculated. Δ-PPFE >1.25% defined progressive PPFE above scan noise. Mixed-effects models evaluated Δ-PPFE against change in visual CT interstitial lung disease (ILD) extent and annualised forced vital capacity (FVC) decline. Multivariable models were adjusted for age, sex, smoking history, baseline emphysema presence, antifibrotic use and diffusion capacity of the lung for carbon monoxide. Mortality analyses further adjusted for baseline presence of clinically important PPFE-like lesions and ILD change. RESULTS: Δ-PPFE associated weakly with ILD and FVC change. 22-26% of IPF and FHP cohorts demonstrated progressive PPFE-like lesions which independently associated with mortality in the IPF cohort (hazard ratio 1.25, 95% CI 1.16-1.34, p<0.0001) and the FHP cohort (hazard ratio 1.16, 95% CI 1.00-1.35, p=0.045). INTERPRETATION: Progression of PPFE-like lesions independently associates with mortality in IPF and FHP but does not associate strongly with measures of fibrosis progression