629 research outputs found
Response to Tomenson's letter on 'Lung cancer mortality in the French cohort of titanium dioxide workers: some aetiological insights'.
International audienc
Effective boundary conditions for dense granular flows
We derive an effective boundary condition for granular flow taking into
account the effect of the heterogeneity of the force network on sliding
friction dynamics. This yields an intermediate boundary condition which lies in
the limit between no-slip and Coulomb friction; two simple functions relating
wall stress, velocity, and velocity variance are found from numerical
simulations. Moreover, we show that this effective boundary condition
corresponds to Navier slip condition when GDR MiDi's model is assumed to be
valid, and that the slip length depends on the length scale that characterises
the system, \emph{viz} the particle diameter.Comment: 4 pages, 5 figure
Walkability and street intersections in rural-urban fringes: a decision aiding evaluation procedure
We propose a decision-aiding evaluation procedure (i) for classifying road crossings based on their impact on walkability and, subsequently, (ii) for prioritising street improvements, in urban-rural fringe areas. In the peripheral urban-rural fringes, pedestrian mobility is usually less developed and people generally depend more on cars for their everyday chores. Partly this is inevitable given the structural features and supply of services and activities in such areas, but part is due to a frequent neglect of pedestrian mobility in planning and urban design. Measures to improve this state of affairs can include the design of more pedestrian-friendly environments offering to potential users a greater level of security, comfort and convenience when walking to their designated destinations. Our evaluation procedure combines a walkability assessment methodology with the ELECTRE TRI rating procedure, in order to assist planners and decision makers in designing physical streets to enhance the continuity, safety and quality of pedestrian paths. Improving the walking accessibility in the fringe areas of towns is a way to reduce the physical and perceptual distance which separates these contexts from the rest of the city, thus leading to a progressive integration of urban functions
Shear bands in granular flow through a mixing length model
We discuss the advantages and results of using a mixing-length, compressible
model to account for shear banding behaviour in granular flow. We formulate a
general approach based on two function of the solid fraction to be determined.
Studying the vertical chute flow, we show that shear band thickness is always
independent from flowrate in the quasistatic limit, for Coulomb wall boundary
conditions. The effect of bin width is addressed using the functions developed
by Pouliquen and coworkers, predicting a linear dependence of shear band
thickness by channel width, while literature reports contrasting data. We also
discuss the influence of wall roughness on shear bands. Through a Coulomb wall
friction criterion we show that our model correctly predicts the effect of
increasing wall roughness on the thickness of shear bands. Then a simple
mixing-length approach to steady granular flows can be useful and
representative of a number of original features of granular flow.Comment: submitted to EP
An Exploratory Assessment of Applying Risk Management Practices to Engineered Nanomaterials
The widespread industrial application of nanotechnology has increased the number of workers exposed to engineered nanomaterials (ENMs), but it is not clear to what extent prevention guidance is practiced. Our aim was to explore the extent that companies manufacturing and/or using ENMs apply risk assessment and management measures. Thirty-four companies were surveyed with an international 35-item questionnaire investigating company and workforce features, types of ENM handled, and risk evaluation and preventive measures adopted. Among participating companies, 62% had a maximum of 10 employees. Metal-based nanomaterials were most frequently identified (73%). Environmental monitoring was performed by 41% of the companies, while engineering exposure controls were approximately reported by 50%. Information and training programs were indicated by 85% of the sample, only 9% performed specific health surveillance for ENM workers. Personal protective equipment primarily included gloves (100%) and eye/face protection (94%). This small-scale assessment can contribute to the limited amount of published literature on the topic. Future investigations should include a greater number of companies to better represent ENM workplaces and a direct access to industrial settings to collect information on site. Finally, deeper attention should be paid to define standardized frameworks for ENM risk assessment that may guide nano-specific preventive actions
Young Adult Romantic Couples’ Conflict Resolution And Satisfaction Varies With Partner's Attention–Deficit/Hyperactivity Disorder Type
Attention-deficit/hyperactivity disorder (ADHD) has previously been associated with lesssatisfaction and success in romantic relationships. This study compares conflict resolutionand problem-solving behaviors in young adult romantic couples either having one partnerwith ADHD combined type (C-couples), having one partner identified with ADHD inattentivetype (IA-couples), or in which neither partner has an ADHD diagnosis (nondiagnosed[ND] couples). Self-reports of current and childhood ADHD symptoms corroborated diagnosticstatus and speaker and listener behaviors, coded via the Rapid Couples InteractionScoring System (Gottman, 1996), were the primary dependent variables. Analyses revealedgreater negativity and less positivity in C-couples’ behavior during a conflict resolution task,relative to IA and ND couples, and this corresponded with couples’ relational satisfaction.IA-couples emitted relational behavior that was largely similar to ND couples. Findings supportthat relational impairment exists in C-couples, and to some degree, contrast with previousresearch suggesting that individuals with predominant inattention experience greatersocial impairment in adulthood than those with other types of ADHD
In search of phylogenetic congruence between molecular and morphological data in bryozoans with extreme adult skeletal heteromorphy
peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tsab20© Crown Copyright 2015. This document is the author's final accepted/submitted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it
Brief Cognitive Behavioral Therapy For College Students With ADHD: A Case Series Report
Attention-deficit/hyperactivity disorder (ADHD) is often diagnosed in childhood but persists into adulthood in many cases. Thisdisorder, which is defined by the core symptoms of IA and HI, is also associated with impairment in academic settings, interpersonalrelationships, and behavioral risk taking. While ADHD is most often treated with medication (e.g., stimulants), brief psychosocialtreatments have also been shown to produce improvement in adults with ADHD, although these have not been adequately tested incollege-age populations. The current study tested a brief, eight-session cognitive-behavioral protocol in a case-series design with fourcollege students with ADHD. Participants completed measures tapping ADHD symptoms, anxiety, depression, and general impairmentin academic, social, and employment domains. The findings indicate that the protocol may be useful as a short-term treatment option forcollege students with ADHD, warranting further study in controlled trials
the topography of brain microstructural damage in amyotrophic lateral sclerosis assessed using diffusion tensor mr imaging
BACKGROUND AND PURPOSE: ALS leads to macrostructural (ie, cortical atrophy and hyperintensities along the corticospinal tract) and microstructural (ie, gray matter intrinsic damage) central nervous system abnormalities. We used a multimodal voxelwise imaging approach to assess microstructural changes independent of macrostructural volume loss in patients with ALS compared with HCs. MATERIALS AND METHODS: Twenty-three patients with ALS and 14 HCs were studied. Conventional imaging and DTI were performed. Images were processed by using SPM5 to assess measures of gray and white matter atrophy as well as microstructural damage (ie, MD and FA). DTI alterations independent of volume loss were investigated. RESULTS: When we accounted for both gray and white matter atrophy, patients with ALS showed increased MD values in several gray and white matter areas mainly located in the orbitofrontal and frontotemporal regions bilaterally, in the right genu of the corpus callosum, and in the right posterior limb of the internal capsule. When we accounted for white matter volume loss, patients with ALS showed decreased FA along the corticospinal tract bilaterally and in the left inferior frontal lobe relative to HCs. The MD of the orbitofrontal regions bilaterally was associated significantly with disease duration. CONCLUSIONS: In patients with ALS, DTI detects microstructural changes independent of brain tissue loss. The affected regions included both motor and extramotor areas. The extent of ALS-related DTI abnormalities was greater than that disclosed by the volumetric analysis
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