Interfacial separation between elastic solids with randomly rough surfaces: comparison of experiment with theory

We study the average separation between an elastic solid and a hard solid with a nominal flat but randomly rough surface, as a function of the squeezing pressure. We present experimental results for a silicon rubber (PDMS) block with a flat surface squeezed against an asphalt road surface. The theory shows that an effective repulse pressure act between the surfaces of the form p proportional to exp(-u/u0), where u is the average separation between the surfaces and u0 a constant of order the root-mean-square roughness, in good agreement with the experimental results.Comment: 6 pages, 10 figure

Attitudes to kidney donation among primary care patients in rural Crete, Greece

<p>Abstract</p> <p>Background</p> <p>In Greece, there is limited research on issues related to organ donation, and the low rate of registration as donors requires explanation. This study reports the findings of a survey of knowledge and attitudes to kidney donation among primary care patients in rural Crete, Greece.</p> <p>Methods</p> <p>Two rural primary care settings in the island of Crete, Anogia Health Centre and Vrachasi Practice, were involved in a questionnaire survey. This was conducted among primary care patients (aged 18 years and over) with routine appointments, to assess their knowledge and attitudes to kidney donation. General practitioners (GPs) recruited patients and questionnaires were completed following the patients' medical consultation. Pearson's chi square tests were used and crude odds ratios (OR) with 95% confidence intervals (95% CI) were calculated in order to investigate into the possible associations between the respondents' knowledge, attitudes and specific concerns in relation to their socio-demographic features. Logistic regression analyses were used to examine differences by geographical location.</p> <p>Results</p> <p>The 224 (92.5%) of the 242 primary care attenders who were approached agreed to participate. Only 2.2% (5/224) of the respondents carried a donor card. Most participants (84.4%, 189/224) did not feel well informed about registering as a kidney donor. More than half of the respondents (54.3%, 121/223) were unwilling to register as a kidney donor and donate kidneys for transplant after death. Over a third of respondents (35.4%, 79/223) were not confident that medical teams would try as hard as possible to save the life of a person who has agreed to donate organs. People with a higher level of education were more likely to be willing to register as kidney donors [(OR: 3.3; 95% CI: 1.8–6.0), p < 0.001)] and to be less worried about their kidneys being removed after death [(OR: 0.3; 95% CI: 0.1–0.5), p < 0.001)] than those having a lower level of education.</p> <p>Conclusion</p> <p>Lack of knowledge and information regarding organ donation and negative attitudes related to registration as donors were the main findings of this study. Efforts should be based on targeting the attitudes to organ donation of individuals and population groups.</p

Goettingen Minipigs (GMP): Comparison of Two Different Models for Inducing Diabetes

Purpose: Preclinical experiments on large animals are indispensable for evaluating the effectiveness of diabetes therapies. Miniature swine are well suited for such studies due to their physiological and pathophysiological responses. Methods: We compare two methods for inducing diabetes in Goettingen minipigs (GMP), in five with the beta cell toxin streptozotocin (STZ) and in five other GMP by total pancreatectomy (PE). Glucose homeostasis was assessed with the intravenous glucose-tolerance test (IVGTT) and continual monitoring of interstitial glucose levels. At conclusion of the observation period, the pancreata were examined histologically. Three non-diabetic GMP served as control group. Results: The IVGTT revealed markedly diabetic profiles in both GMP groups. STZ-GMP were found to harbor residual C-peptides and scattered insulin-positive cells in the pancreas. PE-GMP survived the total pancreatectomy only with intensive postoperative care. Conclusions: Although both methods reliably induced diabetes in GMP, the PE-GMP clearly had more health problems and required a greater expenditure of time and resources. The PE-GMP model, however, was better at eliminating endogenous insulin and C-peptide than the STZ-GMP model

The impact of donor policies in Europe: a steady increase, but not everywhere

<p>Abstract</p> <p>Background</p> <p>Transplantable organs are scarce everywhere. Therefore, countries have developed policies to support the efficient use of potential donors. Nevertheless, the shortage of organs remains. Were these policies in vain? The aim of this study is to assess the impact of donor policies on donor procurement in 10 Western European countries from 1995 to 2005.</p> <p>Method</p> <p>To assess the impact of the donor policies we studied the conversion of potential donors into effectuated donors. 80% of the donors died from CVAs or a (traffic) accident. We considered these mortality rates to be a good proxy for potential donors. Here we call the conversion of potential donors into actual donors 'the donor efficiency rate by proxy'.</p> <p>Results</p> <p>The mortality rates for CVA and (traffic) accidents have decreased in the countries under study. At the same time, in most countries the donor efficiency rates have steadily increased. The variance in donor efficiency rates between countries has also increased from 1995 to 2005. Four countries introduced a new consent system or changed their existing system, without (visible) long-term effects.</p> <p>Conclusion</p> <p>The overall increase in donor efficiency means that the efforts to improve donor policies have paid off. However, substantial differences between countries were found. The success of donor policies in terms of the number of absolute donors is blurred by the success of policies on traffic safety and CVA treatment. It remains unclear which specific policy measures are responsible for the increase in donor efficiency rates. This increase is not related to having a presumed consent system. Furthermore, an analysis of countries that introduced a new consent system or changed their system showed no effect on donor efficiency.</p

Mental health of refugees following state-sponsored repatriation from Germany

von Lersner U, Elbert T, Neuner F. Mental health of refugees following state-sponsored repatriation from Germany. BMC Psychiatry. 2008;8(1): 88.BACKGROUND: In recent years, Voluntary Assisted Return Programmes (VARPs) have received increasing funding as a potential way of reducing the number of refugees in EU member states. A number of factors may affect the mental well-being of returnees. These include adjustment to the home country following return, difficult living conditions, and long-term effects resulting from the severe traumatic stress that had originally driven the affected out of their homes. Little is known about the extent to which these and other factors may promote or inhibit the willingness of refugees to return to their country of origin. The present pilot study investigated refugees who returned to their country of origin after having lived in exile in Germany for some 13 years. METHODS: Forty-seven VARP participants were interviewed concerning their present living conditions, their views of their native country, and their attitudes towards a potential return prior to actually returning. 33 participants were interviewed nine months after returning to their country of origin. Mental health and well-being were assessed using the questionnaires Posttraumatic Stress Diagnostic Scale (PDS) and EUROHIS and the structured Mini International Neuropsychiatric Interview (M.I.N.I.).Our objectives were to examine the mental health status of refugees returning to their home country following an extended period of exile. We also aimed to assess the circumstances under which people decided to return, the current living conditions in their home country, and retrospective returnee evaluations of their decision to accept assisted return. RESULTS: Prior to returning to their home country, participants showed a prevalence rate of 53% for psychiatric disorders. After returning, this rate increased to a sizeable 88%. Substantial correlations were found between the living situation in Germany, the disposition to return, and mental health. For two thirds of the participants, the decision to return was not voluntary. CONCLUSION: Psychological strain among study participants was of a considerable magnitude. As a result of traumatic stress experienced during war and refuge, victims were vulnerable and not well equipped to cope with either post-migration stressors in exile or with a return to their country of origin. It is noteworthy that the majority returned under pressure from immigration authorities. Living conditions after return (such as housing, work, and health care) were poor and unstable. Participants also had great difficulty readapting to the cultural environment after having lived abroad for an average of 13 years. Current VARPs do not take these factors into account and are therefore not able to assist in a humanitarian reintegration of voluntary returnees

Disparate Impact of Butyroyloxymethyl Diethylphosphate (AN-7), a Histone Deacetylase Inhibitor, and Doxorubicin in Mice Bearing a Mammary Tumor

The histone deacetylase inhibitor (HDACI) butyroyloxymethyl diethylphosphate (AN-7) synergizes the cytotoxic effect of doxorubicin (Dox) and anti-HER2 on mammary carcinoma cells while protecting normal cells against their insults. This study investigated the concomitant changes occurring in heart tissue and tumors of mice bearing a subcutaneous 4T1 mammary tumor following treatment with AN-7, Dox, or their combination. Dox or AN-7 alone led to inhibition of both tumor growth and lung metastases, whereas their combination significantly increased their anticancer efficacy and attenuated Dox- toxicity. Molecular analysis revealed that treatment with Dox, AN-7, and to a greater degree, AN-7 together with Dox increased tumor levels of γH2AX, the marker for DNA double-strand breaks and decreased the expression of Rad51, a protein needed for DNA repair. These events culminated in increased apoptosis, manifested by the appearance of cytochrome-c in the cytosol. In the myocardium, Dox-induced cardiomyopathy was associated with an increase in γH2AX expression and a reduction in Rad51 and MRE11 expression and increased apoptosis. The addition of AN-7 to the Dox treatment protected the heart from Dox insults as was manifested by a decrease in γH2AX levels, an increase in Rad51 and MRE11 expression, and a diminution of cytochrome-c release. Tumor fibrosis was high in untreated mice but diminished in Dox- and AN-7-treated mice and was almost abrogated in AN-7+Dox-treated mice. By contrast, in the myocardium, Dox alone induced a dramatic increase in fibrosis, and AN7+Dox attenuated it. The high expression levels of c-Kit, Ki-67, c-Myc, lo-FGF, and VEGF in 4T1 tumors were significantly reduced by Dox or AN-7 and further attenuated by AN-7+Dox. In the myocardium, Dox suppressed these markers, whereas AN-7+Dox restored their expression. In conclusion, the combination of AN-7 and Dox results in two beneficial effects, improved anticancer efficacy and cardioprotection

Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

First published: 16 February 202

A large-scale genome-wide association study meta-analysis of cannabis use disorder

Summary Background Variation in liability to cannabis use disorder has a strong genetic component (estimated twin and family heritability about 50–70%) and is associated with negative outcomes, including increased risk of psychopathology. The aim of the study was to conduct a large genome-wide association study (GWAS) to identify novel genetic variants associated with cannabis use disorder. Methods To conduct this GWAS meta-analysis of cannabis use disorder and identify associations with genetic loci, we used samples from the Psychiatric Genomics Consortium Substance Use Disorders working group, iPSYCH, and deCODE (20 916 case samples, 363 116 control samples in total), contrasting cannabis use disorder cases with controls. To examine the genetic overlap between cannabis use disorder and 22 traits of interest (chosen because of previously published phenotypic correlations [eg, psychiatric disorders] or hypothesised associations [eg, chronotype] with cannabis use disorder), we used linkage disequilibrium score regression to calculate genetic correlations. Findings We identified two genome-wide significant loci: a novel chromosome 7 locus (FOXP2, lead single-nucleotide polymorphism [SNP] rs7783012; odds ratio [OR] 1·11, 95% CI 1·07–1·15, p=1·84 × 10−9) and the previously identified chromosome 8 locus (near CHRNA2 and EPHX2, lead SNP rs4732724; OR 0·89, 95% CI 0·86–0·93, p=6·46 × 10−9). Cannabis use disorder and cannabis use were genetically correlated (rg 0·50, p=1·50 × 10−21), but they showed significantly different genetic correlations with 12 of the 22 traits we tested, suggesting at least partially different genetic underpinnings of cannabis use and cannabis use disorder. Cannabis use disorder was positively genetically correlated with other psychopathology, including ADHD, major depression, and schizophrenia. Interpretation These findings support the theory that cannabis use disorder has shared genetic liability with other psychopathology, and there is a distinction between genetic liability to cannabis use and cannabis use disorder. Funding National Institute of Mental Health; National Institute on Alcohol Abuse and Alcoholism; National Institute on Drug Abuse; Center for Genomics and Personalized Medicine and the Centre for Integrative Sequencing; The European Commission, Horizon 2020; National Institute of Child Health and Human Development; Health Research Council of New Zealand; National Institute on Aging; Wellcome Trust Case Control Consortium; UK Research and Innovation Medical Research Council (UKRI MRC); The Brain & Behavior Research Foundation; National Institute on Deafness and Other Communication Disorders; Substance Abuse and Mental Health Services Administration (SAMHSA); National Institute of Biomedical Imaging and Bioengineering; National Health and Medical Research Council (NHMRC) Australia; Tobacco-Related Disease Research Program of the University of California; Families for Borderline Personality Disorder Research (Beth and Rob Elliott) 2018 NARSAD Young Investigator Grant; The National Child Health Research Foundation (Cure Kids); The Canterbury Medical Research Foundation; The New Zealand Lottery Grants Board; The University of Otago; The Carney Centre for Pharmacogenomics; The James Hume Bequest Fund; National Institutes of Health: Genes, Environment and Health Initiative; National Institutes of Health; National Cancer Institute; The William T Grant Foundation; Australian Research Council; The Virginia Tobacco Settlement Foundation; The VISN 1 and VISN 4 Mental Illness Research, Education, and Clinical Centers of the US Department of Veterans Affairs; The 5th Framework Programme (FP-5) GenomEUtwin Project; The Lundbeck Foundation; NIH-funded Shared Instrumentation Grant S10RR025141; Clinical Translational Sciences Award grants; National Institute of Neurological Disorders and Stroke; National Heart, Lung, and Blood Institute; National Institute of General Medical Sciences.Peer reviewe