415 research outputs found

    Effect of a columnar defect on the shape of slow-combustion fronts

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    We report experimental results for the behavior of slow-combustion fronts in the presence of a columnar defect with excess or reduced driving, and compare them with those of mean-field theory. We also compare them with simulation results for an analogous problem of driven flow of particles with hard-core repulsion (ASEP) and a single defect bond with a different hopping probability. The difference in the shape of the front profiles for excess vs. reduced driving in the defect, clearly demonstrates the existence of a KPZ-type of nonlinear term in the effective evolution equation for the slow-combustion fronts. We also find that slow-combustion fronts display a faceted form for large enough excess driving, and that there is a corresponding increase then in the average front speed. This increase in the average front speed disappears at a non-zero excess driving in agreement with the simulated behavior of the ASEP model.Comment: 7 pages, 7 figure

    Managing change in the nursing handover from traditional to bedside handover – a case study from Mauritius

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    BACKGROUND: The shift handover forms an important part of the communication process that takes place twice within the nurses' working day in the gynaecological ward. This paper addresses the topic of implementing a new system of bedside handover, which puts patients central to the whole process of managing care and also addresses some of the shortcomings of the traditional handover system. METHODS: A force field analysis in terms of the driving forces had shown that there was dissatisfaction with the traditional method of handover which had led to an increase in the number of critical incidents and complaints from patients, relatives and doctors. The restraining forces identified were a fear of accountability, lack of confidence and that this change would lead to more work. A 3 – step planned change model consisting of unfreezing, moving and refreezing was used to guide us through the change process. Resistance to change was managed by creating a climate of open communication where stakeholders were allowed to voice opinions, share concerns, insights, and ideas thereby actively participating in decision making. RESULTS: An evaluation had shown that this process was successfully implemented to the satisfaction of patients, and staff in general. CONCLUSION: This successful change should encourage other nurses to become more proactive in identifying areas for change management in order to improve our health care system

    Proband and Familial Autoimmune Diseases Are Associated With Proband Diagnosis of Autism Spectrum Disorders

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    Objective: There is evidence that parental autoimmune diseases (ADs) are associated with autism spectrum disorders (ASD) in offspring. The association between offspring ASD and ADs diagnosed in siblings and probands remains less clear. We examined whether proband and familial diagnoses of ADs were associated with increased odds of ASD in probands.Method: The study is based on a nested case-control design that used data from a large national birth cohort (N = 1.2 million) in Finland. There were 4,600 cases of ASD and controls matched 1:4 on date of birth, sex, and residence. Data were accessed from national medical, birth, and central registries.Results: Probands had a statistically significant increase in odds of ASD when they (adjusted odds ratio [OR] = 1.2), their mother (adjusted OR = 1.1), or their sibling (adjusted OR = 1.2) were diagnosed with an AD. With regard to specific ADs, we found a statistically significant increase in odds of ASD in probands diagnosed with autoimmune thyroiditis (adjusted OR = 2.7). Further analyses considering ADs by body system yielded a statistically significant increase in odds of ASD in probands with ADs associated with the central/peripheral nervous (adjusted OR = 4.8) and skin/mucous membrane (adjusted OR = 1.3) systems. Probands of mothers diagnosed with ear/eye (adjusted OR = 1.6) or respiratory (adjusted OR = 1.4) ADs, or siblings diagnosed with skin/mucous membrane ADs (adjusted OR = 1.3) also had increased odds of ASD.Conclusion: The findings suggest that there may be common pathogenic, developmental mechanisms related to autoimmunity that are associated with the etiology of ASD.</p

    Finite-temperature correlations in the one-dimensional trapped and untrapped Bose gases

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    We calculate the dynamic single-particle and many-particle correlation functions at non-zero temperature in one-dimensional trapped repulsive Bose gases. The decay for increasing distance between the points of these correlation functions is governed by a scaling exponent that has a universal expression in terms of observed quantities. This expression is valid in the weak-interaction Gross-Pitaevskii as well as in the strong-interaction Girardeau-Tonks limit, but the observed quantities involved depend on the interaction strength. The confining trap introduces a weak center-of-mass dependence in the scaling exponent. We also conjecture results for the density-density correlation function.Comment: 18 pages, Latex, Revtex

    Factors accounting for the association between anxiety and depression, and eczema: the Hordaland health study (HUSK)

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    <p>Abstract</p> <p>Background</p> <p>The association between anxiety and depression, and eczema is well known in the literature, but factors underlying this association remain unclear. Low levels of omega-3 fatty acids and female gender have been found to be associated with both depression and eczema. Somatization and health anxiety are known to be associated with anxiety and depression, further, somatization symptoms and health anxiety have also been found in several dermatological conditions. Accordingly, omega-3 fatty acid supplement, female gender, somatization and health anxiety are possible contributing factors in the association between anxiety and depression, and eczema. The aim of the study is to examine the relevance of proposed contributing factors for the association between anxiety and depression, and eczema, including, omega-3 fatty acid supplement, female gender, health anxiety and somatization.</p> <p>Methods</p> <p>Anxiety and depression was measured in the general population (n = 15715) employing the Hospital Anxiety and Depression Scale (HADS). Information on eczema, female gender, omega-3 fatty acid supplement, health anxiety and somatization was obtained by self-report.</p> <p>Results</p> <p>Somatization and health anxiety accounted for more than half of the association between anxiety/depression, and eczema, while the other factors examined were of minor relevance for the association of interest.</p> <p>Conclusions</p> <p>We found no support for female gender and omega-3 fatty acid supplement as contributing factors in the association between anxiety/depression, and eczema. Somatization and health anxiety accounted for about half of the association between anxiety/depression, and eczema, somatization contributed most. The association between anxiety/depression, and eczema was insignificant after adjustment for somatization and health anxiety. Biological mechanisms underlying the mediating effect of somatization are yet to be revealed.</p

    Tree height strongly affects estimates of water-use efficiency responses to climate and CO2 using isotopes

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    Various studies report substantial increases in intrinsic water-use efficiency (Wi), estimated using carbon isotopes in tree rings, suggesting trees are gaining increasingly more carbon per unit water lost due to increases in atmospheric CO2. Usually, reconstructions do not, however, correct for the effect of intrinsic developmental changes in Wi as trees grow larger. Here we show, by comparingWi across varying tree sizes at one CO2 level, that ignoring such developmental effects can severely affect inferences of trees' Wi. Wi doubled or even tripled over a trees' lifespan in three broadleaf species due to changes in tree height and light availability alone, and there are also weak trends for Pine trees. Developmental trends in broadleaf species are as large as the trends previously assigned to CO2 and climate. Credible future tree ring isotope studies require explicit accounting for species-specific developmental effects before CO2 and climate effects are inferred.Peer reviewe

    Characterization of trace metals on soot aerosol particles with the SP-AMS : detection and quantification

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    A method to detect and quantify mass concentrations of trace metals on soot particles by the Aerodyne soot-particle aerosol mass spectrometer (SP-AMS) was developed and evaluated in this study. The generation of monodisperse Regal black (RB) test particles with trace amounts of 13 different metals (Na, Al, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr and Ba) allowed for the determination of the relative ionization efficiency of each metal relative to black carbon (RIEmeas). The observed RIEmeas/RIEtheory values were larger than unity for Na, Rb, Ca, Sr and Ba due to thermal surface ionization (TSI) on the surface of the laser-heated RB particles. Values closer to unity were obtained for the transition metals Zn, Cu, V and Cr. Mn, Fe, and Ni presented the lowest RIEmeas/RIEtheory ratios and highest deviation from unity. The latter discrepancy is unexplained; however it may be related to problems with our calibration method and/or the formation of metal complexes that were not successfully quantified. The response of the metals to the laser power was investigated and the results indicated that a minimum pump laser current of 0.6 A was needed in order to vaporize the metals and the refractory black carbon (rBC). Isotopic patterns of metals were resolved from high-resolution mass spectra, and the mass-weighted size distributions for each individual metal ion were obtained using the high-resolution particle time-of-flight (HR-PToF) method. The RIEmeas values obtained in this study were applied to the data of emission measurements in a heavy-fuel-oil-fired heating station. Emission measurements revealed a large number of trace metals, including evidence for metal oxides and metallic salts, such as vanadium sulfate, calcium sulfate, iron sulfate and barium sulfate, which were identified in the SP-AMS high-resolution mass spectra. SP-AMS measurements of Ba, Fe, and V agreed with ICP-MS analyzed filter samples within a factor of 2 when emitted rBC mass loadings were elevated.Peer reviewe

    Home care in Europe: a systematic literature review

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    <p>Abstract</p> <p>Background</p> <p>Health and social services provided at home are becoming increasingly important. Hence, there is a need for information on home care in Europe. The objective of this literature review was to respond to this need by systematically describing what has been reported on home care in Europe in the scientific literature over the past decade.</p> <p>Methods</p> <p>A systematic literature search was performed for papers on home care published in English, using the following data bases: Cinahl, the Cochrane Library, Embase, Medline, PsycINFO, Sociological Abstracts, Social Services Abstracts, and Social Care Online. Studies were only included if they complied with the definition of home care, were published between January 1998 and October 2009, and dealt with at least one of the 31 specified countries. Clinical interventions, instrument developments, local projects and reviews were excluded. The data extracted included: the characteristics of the study and aspects of home care 'policy & regulation', 'financing', 'organisation & service delivery', and 'clients & informal carers'.</p> <p>Results</p> <p>Seventy-four out of 5,133 potentially relevant studies met the inclusion criteria, providing information on 18 countries. Many focused on the characteristics of home care recipients and on the organisation of home care. Geographical inequalities, market forces, quality and integration of services were also among the issues frequently discussed.</p> <p>Conclusions</p> <p>Home care systems appeared to differ both between and within countries. The papers included, however, provided only a limited picture of home care. Many studies only focused on one aspect of the home care system and international comparative studies were rare. Furthermore, little information emerged on home care financing and on home care in general in Eastern Europe. This review clearly shows the need for more scientific publications on home care, especially studies comparing countries. A comprehensive and more complete insight into the state of home care in Europe requires the gathering of information using a uniform framework and methodology.</p
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