Spontaneous Stratification in Granular Mixtures

Granular materials size segregate when exposed to external periodic perturbations such as vibrations. Moreover, mixtures of grains of different sizes spontaneously segregate in the absence of external perturbations: when a mixture is simply poured onto a pile, the large grains are more likely to be found near the base, while the small grains are more likely to be near the top. Here, we report a spontaneous phenomenon arising when we pour a mixture between two vertical plates: the mixture spontaneously stratifies into alternating layers of small and large grains whenever the large grains are rougher than the small grains. In contrast, we find only spontaneous segregation when the large grains are more rounded than the small grains. The stratification is related to the occurrence of avalanches; during each avalanche the grains comprising the avalanche spontaneously stratify into a pair of layers through a "kink" mechanism, with the small grains forming a sublayer underneath the layer of large grains.Comment: 4 pages, 6 figures, http://polymer.bu.edu/~hmakse/Home.htm

Persistent unexplained congenital clitoromegaly in females born extremely prematurely

Objective: Unexplained clitoromegaly is a rare but well recognised feature in girls born premature. Although detected at birth, girls may re-present during childhood to paediatric urologists and gynaecologists who should be aware of this condition. The aim of the study was to describe the clinical findings and management of a series of girls presenting with persistent congenital clitoromegaly associated with prematurity. / Materials and methods: This was a retrospective notes review set in a tertiary referral centre for Paediatric and Adolescent Gynaecology (PAG). / Results: Eight girls with a mean age of 6 years were seen over an eight year period. In all cases a Disorder of Sex Development (DSD) had been previously excluded. The main symptoms were discomfort or concern about appearance. On examination five girls had excess skin over the clitoris and three had enlarged corporal tissue. Management included reassurance and simple measures to ease discomfort. In two cases the parents requested referral to a paediatric urologist to consider clitoral surgery. / Conclusion: As survival rates for extreme prematurity improve, paediatric urologists and gynaecologists are likely to see more of these cases. Clinicians must be familiar with this condition to ensure children are managed appropriately

Use of fat mass and fat free mass standard deviation scores obtained using simple measurement methods in healthy children and patients: comparison with the reference 4-component model

Background Clinical application of body composition (BC) measurements for individual children has been limited by lack of appropriate reference data. Objectives (1) To compare fat mass (FM) and fat free mass (FFM) standard deviation scores (SDS) generated using new body composition reference data and obtained using simple measurement methods in healthy children and patients with those obtained using the reference 4-component (4-C) model; (2) To determine the extent to which scores from simple methods agree with those from the 4-C model in identification of abnormal body composition. Design FM SDS were calculated for 4-C model, dual-energy X-ray absorptiometry (DXA; GE Lunar Prodigy), BMI and skinfold thicknesses (SFT); and FFM SDS for 4CM, DXA and bioelectrical impedance analysis (BIA; height2/Z)) in 927 subjects aged 3.8–22.0 y (211 healthy, 716 patients). Results DXA was the most accurate method for both FM and FFM SDS in healthy subjects and patients (mean bias (limits of agreement) FM SDS 0.03 (±0.62); FFM SDS −0.04 (±0.72)), and provided best agreement with the 4-C model in identifying abnormal BC (SDS ≤−2 or ≥2). BMI and SFTs were reasonable predictors of abnormal FM SDS, but poor in providing an absolute value. BIA was comparable to DXA for FFM SDS and in identifying abnormal subjects

A novel walkability index for London predicts walking time in adults

Objective: To develop a novel walkability index for London and test it through measurement of associations between neighbourhood walkability and walking among adults using data from the Whitehall II Study. Background: Physical activity is essential for health; walking is the easiest way to incorporate it into everyday life. Many studies have reported positive associations between neighbourhood walkability and walking but the majority have focused on cities in North America and Australasia. Urban form with respect to street connectivity, residential density and land use mix – common components of walkability indices – is likely to differ in European cities. Methods: A walkability index for the 633 spatially contiguous census area statistics wards of London was constructed, comprising three core dimensions associated with walking behaviours: residential dwelling density, street connectivity and land use mix. Walkability was expressed as quartile scores, with wards scoring 1 being in the bottom 25% in terms of walkability, and those scoring 4 in the top 25%. A neighbourhood walkability score was assigned to each London-dwelling Whitehall II Study participant (2003-04, N=3020, mean +/-SD age=61.0y +/-6.0) as the walkability score of the ward in which their residential postcode fell. Associations between neighbourhood walkability and weekly walking time were measured using multiple logistic regression. Results: After adjustment for individual level factors and area deprivation, people in the most walkable neighbourhoods were significantly more likely to spend ≥6hr/wk (Odds Ratio 1.4; 95%Confidence Interval 1.1-1.9), than those in the least walkable. Conclusions: The walkability index constructed can predict walking time in adults: living in a more walkable neighbourhood is associated with longer weekly walking time. The index may help urban planners identify and design neighbourhoods in London with characteristics that are potentially more supportive of walking and, thereby, promote public health

Community Art: Communities of Practice, Situated Learning, Adults and Children as Creators of Cave Art in Upper Palaeolithic France and Northern Spain

AbstractThis paper presents acts of fluting as tangible expressions of activities performed by Palaeolithic communities of practice, in which situated learning was part of the social transmission of knowledge and communities of practice include children, men and women. To identify individual members of the communities of practice who were involved in the creation of parietal art in the Franco-Cantabrian region we have analysed the age and the sex of the people who ‘decorated’ the caves. Secondly, by following the analysis of lines created by flutings by different members of the community of practice, we suggest that children under the age of seven, who had no the cognitive abilities to comprehend the meaning of images, were active and prolific fluters and performed acts of decorating cave walls by themselves or with the support of other community members. This approach allows us to consider parietal art as community art where visual contributions were created by community members of all age and sexes.Gates Cambridge Trust, St John’s College, and the Department of Archaeology, University of Cambridge

Development of a novel walkability index for London, United Kingdom: cross-sectional application to the Whitehall II study

BACKGROUND: Physical activity is essential for health; walking is the easiest way to incorporate activity into everyday life. Previous studies report positive associations between neighbourhood walkability and walking but most focused on cities in North America and Australasia. Urban form with respect to street connectivity, residential density and land use mix-common components of walkability indices-differs in European cities. The objective of this study was to develop a walkability index for London and test the index using walking data from the Whitehall II Study.  METHODS: A neighbourhood walkability index for London was constructed, comprising factors associated with walking behaviours: residential dwelling density, street connectivity and land use mix. Three models were produced that differed in the land uses included. Neighbourhoods were operationalised at three levels of administrative geography: (i) 21,140 output areas, (ii) 633 wards and (iii) 33 local authorities. A neighbourhood walkability score was assigned to each London-dwelling Whitehall II Study participant (2003-04, N = 3020, mean ± SD age = 61.0 years ± 6.0) based on residential postcode. The effect of changing the model specification and the units of enumeration on spatial variation in walkability was examined. RESULTS: There was a radial decay in walkability from the centre to the periphery of London. There was high inter-model correlation in walkability scores for any given neighbourhood operationalisation (0.92-0.98), and moderate-high correlation between neighbourhood operationalisations for any given model (0.39-0.70). After adjustment for individual level factors and area deprivation, individuals in the most walkable neighbourhoods operationalised as wards were more likely to walk >6 h/week (OR = 1.4; 95 % CI: 1.1-1.9) than those in the least walkable. CONCLUSIONS: Walkability was associated with walking time in adults. This walkability index could help urban planners identify and design neighbourhoods in London with characteristics more supportive of walking, thereby promoting public health

ICAM-1 and ICAM-2 Are Differentially Expressed and Up-Regulated on Inflamed Pulmonary Epithelium, but Neither ICAM-2 nor LFA-1: ICAM-1 Are Required for Neutrophil Migration Into the Airways In Vivo

Neutrophil migration into the airways is an important process to fight infection and is mediated by cell adhesion molecules. The intercellular adhesion molecules, ICAM-1 (CD54) and ICAM-2 (CD102) are known ligands for the neutrophil integrins, lymphocyte function associated antigen (LFA)-1 (αLβ2; CD11a/CD18), and macrophage-1 antigen (Mac-1;αMβ2;CD11b/CD18) and are implicated in leukocyte migration into the lung. However, it is ill-defined how neutrophils exit the lung and the role for ICAMs in trans-epithelial migration (TEpM) across the bronchial or alveolar epithelium. We found that human and murine alveolar epithelium expressed ICAM-1, whilst the bronchial epithelium expressed ICAM-2, and both were up-regulated during inflammatory stimulation in vitro and in inflammatory lung diseases such as cystic fibrosis. Although β2 integrins interacting with ICAM-1 and -2 mediated neutrophil migration across human bronchial epithelium in vitro, neither ICAM-2 nor LFA-1 binding of ICAM-1 mediated murine neutrophil migration into the lung or broncho-alveolar space during LPS-induced inflammation in vivo. Furthermore, TEpM of neutrophils themselves resulted in increased epithelial junctional permeability and reduced barrier function in vitro. This suggests that although β2 integrins interacting with ICAMs may regulate low levels of neutrophil traffic in healthy lung or early in inflammation when the epithelial barrier is intact; these interactions may be redundant later in inflammation when epithelial junctions are disrupted and no longer limit TEpM

The Debrisoft ® monofilament debridement pad for use in acute or chronic wounds: A NICE medical technology guidance

As part of its Medical Technology Evaluation Programme, the National Institute for Health and Care Excellence (NICE) invited a manufacturer to provide clinical and economic evidence for the evaluation of the Debrisoft ® monofilament debridement pad for use in acute or chronic wounds. The University of Birmingham and Brunel University, acting as a consortium, was commissioned to act as an External Assessment Centre (EAC) for NICE, independently appraising the submission. This article is an overview of the original evidence submitted, the EAC’s findings and the final NICE guidance issued. The sponsor submitted a simple cost analysis to estimate the costs of using Debrisoft® to debride wounds compared with saline and gauze, hydrogel and larvae. Separate analyses were conducted for applications in home and applications in a clinic setting. The analysis took an UK National Health Service (NHS) perspective. It incorporated the costs of the technologies and supplementary technologies (such as dressings) and the costs of their application by a district nurse. The sponsor concluded that Debrisoft® was cost saving relative to the comparators. The EAC made amendments to the sponsor analysis to correct for errors and to reflect alternative assumptions. Debrisoft® remained cost saving in most analyses and savings ranged from £77 to £222 per patient compared with hydrogel, from £97 to £347 compared with saline and gauze, and from £180 to £484 compared with larvae depending on the assumptions included in the analysis and whether debridement took place in a home or clinic setting. All analyses were severely limited by the available data on effectiveness, in particular a lack of comparative studies and that the effectiveness data for the comparators came from studies reporting different clinical endpoints compared with Debrisoft®. The Medical Technologies Advisory Committee made a positive recommendation for adoption of Debrisoft® and this has been published as a NICE medical technology guidance (MTG17).The Birmingham and Brunel Consortium is funded by NICE to act as an External Assessment Centre for the Medical Technologies Evaluation Programme