3,257 research outputs found
Heavy particle concentration in turbulence at dissipative and inertial scales
Spatial distributions of heavy particles suspended in an incompressible
isotropic and homogeneous turbulent flow are investigated by means of high
resolution direct numerical simulations. In the dissipative range, it is shown
that particles form fractal clusters with properties independent of the
Reynolds number. Clustering is there optimal when the particle response time is
of the order of the Kolmogorov time scale . In the inertial range,
the particle distribution is no longer scale-invariant. It is however shown
that deviations from uniformity depend on a rescaled contraction rate, which is
different from the local Stokes number given by dimensional analysis. Particle
distribution is characterized by voids spanning all scales of the turbulent
flow; their signature in the coarse-grained mass probability distribution is an
algebraic behavior at small densities.Comment: 4 RevTeX pgs + 4 color Figures included, 1 figure eliminated second
part of the paper completely revise
A study of quality and speed of handwriting used by adults,
Thesis (Ed.M)--Boston Universit
Incidence, Severity and Responses to Reportable Student Self-Harm and Suicidal Behaviours in Schools: A One-Year Population-Based Study
2020, The Author(s). School staff have a unique opportunity to detect and respond to mental health issues including self-harm and suicidal behaviour in adolescents. There is limited knowledge about how these incidents are managed in schools. This study aims to understand the incidence rates, perceived severity and management of self-harm and suicidal behaviour incidents by schools. A total of 1525 school incidents were analysed for rate, severity and response. Pearson\u27s χ2 test was used to understand incident rates of self-harm and suicidal behaviours compared to all other incidents, and if incident category was related to emergency service involvement. A Kruskal-Wallis ANOVA analysed differences in severity ratings for incidents, and relative risk ratios determined the probability that first responder services will be engaged in self-harm and suicidal behaviour incidents. Self-harm and suicidal behaviour incidents (n = 77) accounted for 5.05% of all incidents and were more likely to be rated highly severe compared to other incidents. Incidents of self-harm and suicidal behaviours were 1.43 times more likely to have police involvement and 8.37 times more likely to have ambulance involvement compared to other incidents that caused harm to students, staff or property including welfare and violence incidents. The findings highlight the severity of reportable self-harm and suicidal behaviour incidents as they required an emergency response. We discuss the potential missed opportunity for early intervention by school staff and services, which may hinder future disclosure or help-seeking by at-risk young people. Training of school staff may provide knowledge and confidence to respond appropriately to self-harm and suicidal behaviour incidents and prevent escalation requiring emergency intervention
Raman excitation spectroscopy of carbon nanotubes: effects of pressure medium and pressure
Raman excitation and emission spectra for the radial breathing mode (RBM) are
reported, together with a preliminary analysis. From the position of the peaks
on the two-dimensional plot of excitation resonance energy against Raman shift,
the chiral indices (m, n) for each peak are identified. Peaks shift from their
positions in air when different pressure media are added - water, hexane,
sulphuric acid - and when the nanotubes are unbundled in water with surfactant
and sonication. The shift is about 2 - 3 cm-1 in RBM frequency, but
unexpectedly large in resonance energy, being spread over up to 100meV for a
given peak. This contrasts with the effect of pressure. The shift of the peaks
of semiconducting nanotubes in water under pressure is orthogonal to the shift
from air to water. This permits the separation of the effects of the pressure
medium and the pressure, and will enable the true pressure coefficients of the
RBM and the other Raman peaks for each (m, n) to be established unambiguously.Comment: 6 pages, 3 Figures, Proceedings of EHPRG 2011 (Paris
Growth and Empowerment for Indigenous Australians in Substance Abuse Treatment
This paper describes psychosocial outcomes of an Indigenous residential substance abuse rehabilitation centre in Australia, examines the sensitivity to change of the new Growth and Empowerment Measure (GEM), and explores the degree to which service users value cultural components of the treatment program. Participants were 57 Indigenous and 46 non-Indigenous male clients from Oolong House. Intake, 8-weeks, and 16-weeks (program completion) measures of Kessler 10 Psychological Distress Scale (K10), Drug Taking Confidence Questionnaire (DTCQ-8), and GEM were completed. The Treatment Component Evaluation (TCE) was completed at 16-weeks. There were significant improvements for participants, with a decrease in psychological distress and increases in refusal self-efficacy and empowerment. Effect sizes for GEM were medium to large across the time-points (r00.61 to 0.70 for all four subscales from baseline to 8-weeks; r00.44 to 0.70 for three subscales from 8-weeks to 16-weeks), indicating sensitivity to change. Indigenous participants rated cultural components of treatment significantly more helpful than did non-Indigenous participants. Implications for future research and substance abuse interventions for Indigenous Australians are discussed
Oral Mutian®X stopped faecal feline coronavirus shedding by naturally infected cats
Feline coronavirus (FCoV) is common among cats living indoors in groups. In about 10% of infected cats, a potentially lethal disease, feline infectious peritonitis (FIP) occurs. Virus transmission is faecal-oral. Mutian® Xraphconn (Mutian X) is a product marketed to treat cats with FIP but is also being used to stop virus shedding, although no clear guidelines exist for its use for this purpose. The aim of this study was to establish the minimum dose and treatment duration required to ensure viral clearance from the faeces of asymptomatic virus-shedding cats. In five multicat households, 29 cats naturally infected with FCoV and actively shedding virus in the faeces were given Mutian X pills. Virus shedding was monitored using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) controlled for faecal inhibitors to ensure sensitivity. Mutian X given orally cleared the virus in 29 cats; although four cats required a repeated course to finally stop virus shedding. A dose of 4 mg/kg q24 h for four days was found to be the optimal treatment protocol: 2 mg/kg cleared only 80% of cats. Post-treatment using a sensitive RT-qPCR test was essential to ensure that virus clearance had been achieved, since failure to clear even one cat can result in re-infection of the others. Records of virus shedding by cats before treatment provided a retrospective control: significantly more cats stopped shedding virus after Mutian X than recovered from infection during the control period (p < .00001). This is the first report of the successful elimination of faecal FCoV shedding in chronically infected cats
Strengthening Europe's Capability in Biological Ocean Observations
This publication is primarily aimed at stakeholders involved in ocean observing, spanning diverse roles from commissioning,
managing, funding and coordinating, to developing, implementing, or advising on, ocean observation programmes.
Such programmes will have strategic and policy drivers but their main purpose may vary from predominantly researchdriven
scientific purposes to environmental monitoring for providing data and reporting to legally-binding regulations or
directives. The main focus is on European capabilities but set in a global context with the various actors spanning a variety
of geographical scales from national to regional and European. Key stakeholder organizations include environmental or
other agencies; marine research institutions, their researchers and operators; international and regional ocean observing
initiatives and programmes; national, regional and European policy makers and their advisors; national stations for
observations; etc.). It will also be of interest to the wider marine and maritime research and policy community.
The main aim of the publication is to increase the relevance of current (and future) European biological ocean observation
capacity to strengthen global efforts towards our understanding of the ocean and enhance marine biodiversity
conservation, for maintaining a healthy ocean for healthy societies.
This document explains why biological ocean observations are needed to assess progress against national and international
conservation targets, the Sustainable Development Goals (SDGs), the Blue Growth agenda and to contribute to key EU
directives including the Marine Strategy Framework Directive (MSFD). To achieve this, the publication highlights the need
of biological ocean observations to reflect clearly defined hypotheses about potential causes of change, including the
combined impacts of local and global drivers, and to support the management of our impacts on the ocean. Additionally,
it calls for flexible biological ocean observing programmes to capture the relevant drivers operating at multiple spatial
scales, by networking and integration of ongoing monitoring programmes, methodological standardization and
appropriate policies of data integration and dissemination. It then presents key variables, elements and information
products to inform on the status and trends of marine biodiversity
Bubbly two-phase flow in hydraulic jumps at large Froude numbers
A hydraulic jump is a sudden, rapid transition from a supercritical flow to a subcritical flow. At large inflow Froude numbers, the jump is characterized by a significant amount of entrained air. For this paper, the bubbly two-phase flow properties of steady and strong hydraulic jumps were investigated experimentally. The results demonstrate that the strong air entrainment rate and the depth-averaged void-fraction data highlight a rapid deaeration of the jump roller. The results suggest that the hydraulic jumps are effective aerators and that the rate of detrainment is comparatively smaller at the largest Froude numbers. © 2011 American Society of Civil Engineers
Relationships between metabolic profiles and gene expression in liver and leukocytes of dairy cows in early lactation
Publication history: Accepted - 11 October 2020; Published online - 15 January 2021Homeorhetic mechanisms assist dairy cows in the transition from pregnancy to lactation. Less successful cows develop severe negative energy balance (NEB), placing them at risk of metabolic and infectious diseases and reduced fertility. We have previously placed multiparous Holstein Friesian cows from 4 herds into metabolic clusters, using as biomarkers measurements of plasma nonesterified fatty acids, β-hydroxybutyrate, glucose and IGF-1 collected at 14 and 35 d in milk (DIM). This study characterized the global transcriptomic profiles of liver and circulating leukocytes from the same animals to determine underlying mechanisms associated with their metabolic and immune function. Liver biopsy and whole-blood samples were collected around 14 DIM for RNA sequencing. All cows with available RNA sequencing data were placed into balanced (BAL, n = 44), intermediate (n = 44), or imbalanced (IMBAL, n = 19) metabolic cluster groups. Differential gene expression was compared between the 3 groups using ANOVA, but only the comparison between BAL and IMBAL cows is reported. Pathway analysis was undertaken using DAVID Bioinformatic Resources (https://david.ncifcrf.gov/). Milk yields did not differ between BAL and IMBAL cows but dry matter intake was less in IMBAL cows and they were in greater energy deficit at 14 DIM (−4.48 v −11.70 MJ/d for BAL and IMBAL cows). Significantly differentially expressed pathways in hepatic tissue included AMPK signaling, glucagon signaling, adipocytokine signaling, and insulin resistance. Genes involved in lipid metabolism and cholesterol transport were more highly expressed in IMBAL cows but IGF1 and IGFALS were downregulated. Leukocytes from BAL cows had greater expression of histones and genes involved in nucleosomes and cell division. Leukocyte expression of heat shock proteins increased in IMBAL cows, suggesting an unfolded protein response, and several key genes involved in immune responses to pathogens were upregulated (e.g., DEFB13, HP, OAS1Z, PTX3, and TLR4). Differentially expressed genes upregulated in IMBAL cows in both tissues included CD36, CPT1, KFL11, and PDK4, all central regulators of energy metabolism. The IMBAL cows therefore had greater difficulty maintaining glucose homeostasis and had dysregulated hepatic lipid metabolism. Their energy deficit was associated with a reduced capacity for cell division and greater evidence of stress responses in the leukocyte population, likely contributing to an increased risk of infectious disease.This project received funding from the European Union's Seventh Framework Programme (Brussels, Belgium) for research, technological development, and demonstration under grant agreement no. 61368
Probing the properties of convective cores through g modes: high-order g modes in SPB and gamma Doradus stars
In main sequence stars the periods of high-order gravity modes are sensitive
probes of stellar cores and, in particular, of the chemical composition
gradient that develops near the outer edge of the convective core. We present
an analytical approximation of high-order g modes that takes into account the
effect of the mu gradient near the core. We show that in main-sequence models,
similarly to the case of white dwarfs, the periods of high-order gravity modes
are accurately described by a uniform period spacing superposed to an
oscillatory component. The periodicity and amplitude of such component are
related, respectively, to the location and sharpness of the mu gradient.
We investigate the properties of high-order gravity modes for stellar models
in a mass domain between 1 and 10 Msun, and the effects of the stellar mass,
evolutionary state, and extra-mixing processes on period spacing features. In
particular, we show that for models of a typical SPB star, a chemical mixing
that could likely be induced by the slow rotation observed in these stars, is
able to significantly change the g-mode spectra of the equilibrium model.
Prospects and challenges for the asteroseismology of gamma Doradus and SPB
stars are also discussed.Comment: 18 pages, 29 figures, accepted for publication in MNRA
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