Modelling concentration fluctuation moments for spherically symmetric mean concentration

Clarke and Mole (Environmetrics, 6 (1995) 607-617) presented a model for concentration fluctuation moments of a passive scalar dispersing in a turbulent flow. This followed Sullivan and Moseley’s work in making use of the equation for the evolution of the concentration moments integrated over all space, together with Chatwin and Sullivan’s (J. Fluid Mech., 212 (1990) 533-556) description relating higher moments to the mean concentration. The model incorporated a simple closure to express the concentration gradient in terms of the concentration. Numerical results were presented for 1, 2 and 3 spatial dimensions under the assumption that the spatial distribution of the mean concentration was spherically symmetric and Gaussian. Two simple functional forms were used for the spreading rate of the mean cloud. Here those results are briefly summarised. Some asymptotic large time results are also given for spherically symmetric mean concentration of general functional form, and numerical results are obtained for a number of different functional forms

Four layer bandage compared with short stretch bandage for venous leg ulcers: systematic review and meta-analysis of randomised controlled trials with data from individual patients

<p><b>Objective:</b> To compare the effectiveness of two types of compression treatment (four layer bandage and short stretch bandage) in people with venous leg ulceration.</p> <p><b>Design:</b> Systematic review and meta-analysis of patient level data.</p> <p><b>Data:</b> sources Electronic databases (the Cochrane Central Register of Controlled Trials, the Cochrane Wounds Group Specialised Register, Medline, Embase, CINAHL, and National Research Register) and reference lists of retrieved articles searched to identify relevant trials and primary investigators. Primary investigators of eligible trials were invited to contribute raw data for re-analysis.</p> <p><b>Review:</b> methods Randomised controlled trials of four layer bandage compared with short stretch bandage in people with venous leg ulceration were eligible for inclusion. The primary outcome for the meta-analysis was time to healing. Cox proportional hazards models were run to compare the methods in terms of time to healing with adjustment for independent predictors of healing. Secondary outcomes included incidence and number of adverse events per patient.</p> <p><b>Results:</b> Seven eligible trials were identified (887 patients), and patient level data were retrieved for five (797 patients, 90% of known randomised patients). The four layer bandage was associated with significantly shorter time to healing: hazard ratio (95% confidence interval) from multifactorial model based on five trials was 1.31 (1.09 to 1.58), P=0.005. Larger ulcer area at baseline, more chronic ulceration, and previous ulceration were all independent predictors of delayed healing. Data from two trials showed no evidence of a difference in adverse event profiles between the two bandage types.</p> <p><b>Conclusions:</b> Venous leg ulcers in patients treated with four layer bandages heal faster, on average, than those of people treated with the short stretch bandage. Benefits were consistent across patients with differing prognostic profiles.</p&gt

Investigation of the collapse of the skewness and kurtosis exhibited in atmospheric dispersion data

This paper studies the collapse of the estimators for skewness and kurtosis of concentration onto a near universal curve. This phenomenon is observed for data taken from atmospheric dispersion experiments under a variety of different conditions. By means of careful investigation of the high concentration tails, modelled by means of the generalized Pareto distribution, and the fundamental physics of the problem, a set of envelope curves encompassing the data will be established. The implications of these results for modelling the probability density function of concentration are discussed

Comments on the properties and uses of atmospheric dispersion datasets

Great recent improvements in the quality and quantity of atmospheric dispersion datasets have highlighted the crucial importance of concentration fluctuations. However, this has inevitably been accompanied by the realisation that estimating the properties of concentration fluctuations accurately involves new, difficult, but interesting, research problems. Some of these problems are discussed and illustrated. The paper concludes with some recommendations about how research funding agencies (such as governments, regulatory authorities and industry) should change their present strategy in response to new knowledge

Planning for the perfect storm: perceptions of UK mental health professionals on the increasing impacts of climate change on their service users

Introduction Climate change poses a considerable risk of further increasing the world's mental health burden. The ways that, and extent to which, climate change is affecting mental health service users is poorly known. Mental health professionals (MHP)s' views on the nature of climate-related distress and the need for specialist training to support service users is undetermined globally. Methods A questionnaire survey was disseminated to an opportunity sample of MHPs based in the United Kingdom (UK). It investigated whether MHPs perceived that the number of service users mentioning climate change as affecting their mental health or emotional distress had increased in the five years prior to 2021, and if they believe it will increase further. The survey explored MHPs’ perceptions of the influence of climate change on service users’ mental health needs, if they perceive this to be rational, and if they feel adequately prepared to manage climate change related mental health problems or emotional distress. Results We surveyed 75 MHPs, including professionals in psychotherapy (38), psychology (19), psychiatry (6). MHPs reported a significant increase in the perceived prevalence of mental health problems or emotional distress related to climate change, believing this increase will continue. MHPs reported a range of impacts on service users due to climate change, typically viewed as a rational response. MHPs felt equipped to manage the consequences of climate change but would benefit from specific training. Conclusions Our results indicate an increasing incidence of climate-related emotional distress among service users as perceived by MHPs. The expectation among professionals is that this service need is here now but will continue to increase in the future, with potential implications for the provision of training

The spatial variation of the maximum possible contaminant concentration from a steady line source

When considering the possible hazard or nuisance associated with a release of toxic or malodorous gas into the atmosphere, large concentrations are especially important, but relatively little work has been done on measuring or modelling the probability distribution of large concentrations of a contaminant dispersing in a turbulent flow. We have previously applied statistical extreme-value theory to field experiment measurements, analyzing large concentrations at a handful of positions. We have also been involved in using a related moment-based method to give more comprehensive spatial coverage for a steady line source in a wind tunnel. In the latter case, however, we used a method which would be expected to have shortcomings, and we did not calculate confidence intervals for the estimates. In the present paper we use an improved method, with confidence intervals derived from bootstrapping. Again we analyze the measurements from steady line-source wind-tunnel experiments, with particular emphasis on the spatial variation of the estimated maximum possible concentration. We show that the moment-based method agrees well with maximum-likelihood fitting to exceedances of a high threshold. We find that the centreline maximum concentration, normalized by the centreline mean concentration, increases downwind from a value just greater than 1 near the source, to a peak value of 5–6, before decreasing with distance from the source. Across the plume the maximum concentration only varies slowly for the downwind distances in these experiments. These observations are explained in terms of the physical processes of turbulent advection and molecular diffusion

Loss of CLN7 results in depletion of soluble lysosomal proteins and impaired mTOR reactivation

Defects in the MFSD8 gene encoding the lysosomal membrane protein CLN7 lead to CLN7 disease, a neurodegenerative lysosomal storage disorder belonging to the group of neuronal ceroid lipofuscinoses (NCLs). Here we have performed a SILAC-based quantitative analysis of the lysosomal proteome using Cln7-deficient mouse embryonic fibroblasts (MEFs) from a Cln7 knockout (ko) mouse model. From 3335 different proteins identified, we detected 56 soluble lysosomal proteins and 29 highly abundant lysosomal membrane proteins. Quantification revealed that the amounts of 12 different soluble lysosomal proteins were significantly reduced in Cln7 ko MEFs compared with wild type controls. One of the most significantly depleted lysosomal proteins was Cln5 protein that underlies another distinct NCL disorder. Expression analyses showed that the mRNA expression, biosynthesis, intracellular sorting and proteolytic processing of Cln5 were not affected, whereas the depletion of mature Cln5 protein was due to increased proteolytic degradation by cysteine proteases in Cln7 ko lysosomes. Considering the similar phenotypes of CLN5 and CLN7 patients, our data suggest that depletion of CLN5 may play an important part in the pathogenesis of CLN7 disease. In addition, we found a defect in the ability of Cln7 ko MEFs to adapt to starvation conditions as shown by impaired mammalian target of rapamycin complex 1 reactivation, reduced autolysosome tubulation and increased perinuclear accumulation of autolysosomes compared to controls. In summary, depletion of multiple soluble lysosomal proteins suggest a critical role of CLN7 for lysosomal function, which may contribute to the pathogenesis and progression of CLN7 disease