The Douglas-Peucker line simplification algorithm : an introduction with programs

CISRG discussion paper ;

Morphological aspects of the lead dioxide electrode

The technique of scanning electron microscopy has been used to observe morphological changes occurring in the redox processes involved in the interconversion of lead dioxide and lead sulphate. Observations have been made on lead dioxide films on platinum and pure lead substrates and on one and two dimensional porous lead dioxide electrodes supported either by pure lead or lead-antimony alloys. The morphology of the surfaces examined was found to be strongly affected by their history, particularly their charge/discharge cycles. Lead sulphate formed by the self corrosion process was much more porous than that formed by the electrochemical reduction of lead dioxide. For porous lead dioxide electrodes cycled to a constant response, three well defined regions were found to exist within the electrode. The oxidation of lead sulphate on lead and leadantimony alloys has shown that a duplex layer of lead dioxide existed on the lead-antimony alloys only. The primary layer of lead dioxide found on these alloys was analogous to the single layer on the pure lead electrodes. The observations of the morphological changes occurring in the two dimensional porous elect/ trodes were not consistent with the theory of the macrohomogeneous model for porous lead dioxide, possible interpretations of these results are discussed

The clumpiness of molecular clouds: HCO+ (3--2) survey near Herbig-Haro objects

Some well-studied Herbig Haro objects have associated with them one or more cold, dense, and quiescent clumps of gas. We propose that such clumps near an HH object can be used as a general measure of clumpiness in the molecular cloud that contains that HH object. Our aim is to make a survey of clumps around a sample of HH objects, and to use the results to make an estimate of the clumpiness in molecular clouds. All known cold, dense, and quiescent clumps near HH objects are anomalously strong HCO+ emitters. Our method is, therefore, to search for strong HCO+ emission as an indicator of a clump near to an HH object. The searches were made using JCMT and SEST in the HCO+ 3-2 and also H13CO+ 1-0 lines, with some additional searches for methanol and sulphur monoxide lines. The sources selected were a sample of 22 HH objects in which no previous HCO+ emission had been detected. We find that half of the HH objects have clumps detected in the HCO+ 3-2 line and that all searches in H13CO$+ 1-0 lines show evidence of clumpiness. All condensations have narrow linewidths and are evidently unaffected dynamically by the HH jet shock. We conclude that the molecular clouds in which these HH objects are found must be highly heterogeneous on scales of less than 0.1 pc. An approximate calculation based on these results suggests that the area filling factor of clumps affected by HH objects is on the order of 10%. These clumps have gas number densities larger than 3e4 cm-2.Comment: 11 pages, 14 figures. Accepted for publication in Astronomy and Astrophysic

A Wii Bit of Fun: A Novel Platform to Deliver Effective Balance Training to Older Adults

BACKGROUND: Falls and fall-related injuries are symptomatic of an aging population. This study aimed to design, develop, and deliver a novel method of balance training, using an interactive game-based system to promote engagement, with the inclusion of older adults at both high and low risk of experiencing a fall.STUDY DESIGN: Eighty-two older adults (65 years of age and older) were recruited from sheltered accommodation and local activity groups. Forty volunteers were randomly selected and received 5 weeks of balance game training (5 males, 35 females; mean, 77.18 ± 6.59 years), whereas the remaining control participants recorded levels of physical activity (20 males, 22 females; mean, 76.62 ± 7.28 years). The effect of balance game training was measured on levels of functional balance and balance confidence in individuals with and without quantifiable balance impairments.RESULTS: Balance game training had a significant effect on levels of functional balance and balance confidence (P Peer reviewedFinal Published versio

Bases expert statement on the use of music for movement among people with Parkinson's

First published in The Sport and Exercise Scientist, February 2020, Issue 63. Published by the British Association of Sport and Exercise Sciences – www.bases.org.uk.Music is an artistic auditory stimulus that unfolds over time. It can prime specific actions and prompt engagement in physical activity as well as heighten motivation during motor tasks (Karageorghis, 2020). Contrastingly, it can be used to downregulate arousal to facilitate the transition from an active to a sedentary state or to ameliorate anxiety. In therapeutic applications, musical features such as rhythm, melody and harmony have been shown to elicit psychological and physiological changes (Thaut & Hoemberg, 2014). Parkinson’s is a degenerative neurological condition in which the loss of dopamine neurons results in impaired initiation and control of movement, with common symptoms including tremor, postural instability and gait disturbance. There are also non-motor effects that include apathy, anxiety and depression. Medication does not alleviate all manifestations of the condition and there is presently no known cure (Obeso et al., 2017). It is notable that people with Parkinson’s are estimated to be 30% less active than agematched peers (Ramaswamy et al., 2018). Nonetheless, evidence is emerging that a range of exercise-based and social activities that involve musical engagement can serve to address the common symptoms and enhance quality of life (Thaut & Hoemberg, 2014). This statement brings together an international interdisciplinary team to outline what is known about music-related applications for people with Parkinson’s, and to provide recommendations for exercise and health practitioners.Peer reviewe

Urban form strongly mediates the allometric scaling of airshed pollution concentrations

We present allometric-scaling relationships between non-point-source emissions of air pollutants and settlement population, using 3030 urban settlements in Great Britain (home to ca. 80% of the population of that region). Sub-linear scalings (slope  0.6) were found for the oxides of nitrogen (NO _x ) and microscopic airborne particles (PM _10  and PM _2.5 ). That is, emissions of these pollutants from larger cities are lower per capita than would be expected when compared to the same population dispersed in smaller settlements. The scalings of traffic-related emissions are disaggregated into a component due to under-use of roads in small settlements and a fraction due to congestion in large settlements. We use these scalings of emissions, along with a scaling related to urban form, to explain quantitatively how and why urban airshed-average air pollutant concentrations also scale with population. Our predicted concentration scaling with population is strongly sub-linear, with a slope about half that of the emissions scaling, consistent with satellite measurements of NO _2  columns over large cities across Europe. We demonstrate that the urban form of a particular settlement can result in the airshed-average air pollution of that settlement being much larger or smaller than expected. We extend our analysis to predict that the likelihood of occurrence of local air pollution hotspots will scale super-linearly with population, a testable hypothesis that awaits suitable data. Our analysis suggests that coordinated management of emissions and urban form would strongly reduce the likelihood of local pollutant hotspots occurring whilst also ameliorating the urban heat island effect under climate change

Air Pollution Exposure Assessment for Epidemiologic Studies of Pregnant Women and Children: Lessons Learned from the Centers for Children’s Environmental Health and Disease Prevention Research

The National Children’s Study is considering a wide spectrum of airborne pollutants that are hypothesized to potentially influence pregnancy outcomes, neurodevelopment, asthma, atopy, immune development, obesity, and pubertal development. In this article we summarize six applicable exposure assessment lessons learned from the Centers for Children’s Environmental Health and Disease Prevention Research that may enhance the National Children’s Study: a) Selecting individual study subjects with a wide range of pollution exposure profiles maximizes spatial-scale exposure contrasts for key pollutants of study interest. b) In studies with large sample sizes, long duration, and diverse outcomes and exposures, exposure assessment efforts should rely on modeling to provide estimates for the entire cohort, supported by subject-derived questionnaire data. c) Assessment of some exposures of interest requires individual measurements of exposures using snapshots of personal and microenvironmental exposures over short periods and/or in selected microenvironments. d) Understanding issues of spatial–temporal correlations of air pollutants, the surrogacy of specific pollutants for components of the complex mixture, and the exposure misclassification inherent in exposure estimates is critical in analysis and interpretation. e) “Usual” temporal, spatial, and physical patterns of activity can be used as modifiers of the exposure/outcome relationships. f) Biomarkers of exposure are useful for evaluation of specific exposures that have multiple routes of exposure. If these lessons are applied, the National Children’s Study offers a unique opportunity to assess the adverse effects of air pollution on interrelated health outcomes during the critical early life period