A quark model framework for the study of nuclear medium effects

A quark-model framework for studying nuclear medium effects on nucleon resonances is described and applied here to pion photoproduction on the deuteron, which is the simplest composite nucleon system and serves as a first test case. Pion photoproduction on nuclei is discussed within a chiral constituent quark model in which the quark degrees of freedom are explicitly introduced through an effective chiral Lagrangian for the quark-pseudoscalar-meson coupling. The advantage of this model is that a complete set of nucleon resonances can be systematically included with a limited number of parameters. Also, the systematic description of the nucleon and its resonances at quark level allows us to self-consistently relate the nuclear medium's influence on the baryon properties to the intrinsic dynamic aspects of the baryons. As the simplest composite nucleus, the deuteron represents the first application of this effective theory for meson photoproduction on light nuclei. The influence of the medium on the transition operators for a free nucleon is investigated in the Delta resonance region. No evidence is found for a change of the Delta properties in the pion photoproduction reaction on the deuteron since the nuclear medium here involves just one other nucleon and the low binding energy implies low nuclear density. However, we show that the reaction mechanism is in principle sensitive to changes of Delta properties that would be produced by the denser nuclear medium of heavier nuclei through the modification of the quark model parameters.Comment: Revtex, 8 pages, 4 figure

Guidelines for Disclosing Genetic Information to Family Members: from Development to Use

[À l'origine dans / Was originally part of : CRDP - Droit, biotechnologie et rapport au milieu

Human Genetics Society of Australasia Position Statement: Genetic Testing and Personal Insurance Products in Australia.

The expansion of genetic and genomic testing in clinical practice and research, and the growing market for direct-to-consumer genomic testing has led to increased awareness about the impact of this form of testing on insurance. Genetic or genomic information can be requested by providers of mutually rated insurance products, who may then use it when setting premiums or determining eligibility for cover under a particular product. Australian insurers are subject to relevant legislation and an industry led standard that was updated in 2019 to introduce a moratorium on the use of genetic test results in life insurance underwriting for policies <AU$500K. The Human Genetics Society of Australasia has updated its position statement on genetic testing and life insurance to account for these changes and to increase the scope of the statement to include a wider range of personally-rated insurance products, such as life, critical care, and income protection products. Recommendations include that: providers of professional education involving genetics should include ethical, legal, and social aspects of insurance discrimination in their curricula; the Australian Government take a more active role in regulating use of genetic information in personal insurance; that information obtained in the course of a research project be excluded; insurers seek expert advice when making underwriting decisions regarding genetic testing; and engagement between the insurance industry, regulators, and the genetics profession be improved

The association between employment and the health of people with intellectual disabilities:a systematic review

Background:  There is strong evidence indicating that paid employment is generally good for the physical and mental health of the general population. This systematic review considers the association between employment and the health of people with intellectual disabilities.  Methods:  Studies published from 1990 to 2018 were identified via electronic literature databases, email requests and cross-citations. Identified studies were reviewed narratively.  Results: Twelve studies were identified. Studies were generally consistent in reporting an association between being in paid employment and better physical or mental health status.  Conclusions: This review supports the view that the well-established association between employment and better health is similar for adults with and without intellectual disabilities. However, evidence establishing causality is lacking and further research to determine specific health benefits attributable to employment for people with intellectual disabilities and the causal pathways that operate is required

Fighting for a (wide enough) seat at the table: weight stigma in law and policy

Few jurisdictions provide legal protection against discrimination on the basis of weight despite evidence of pervasive inequalities faced by fat individuals in employment, healthcare, education, and other domains. Yet, in the last two decades, advocacy efforts in several countries aimed to remedy this situation have been largely unsuccessful. We present a cross-national conceptual analysis of three significant anti-discrimination developments regarding weight in the United Kingdom, the United States, and Iceland, respectively, to highlight how the creation, implementation, and enforcement of legal and policy mechanisms that prohibit weight discrimination ironically suffer under the very burden of deeply rooted structural stigmas against fatness and fat bodies that such efforts seek to counter. However, drawing on research around policy change in response to other social movements, we conclude that we may be at a time where broad-ranging policy change could become a reality

Relations Among Father's Presence, Family Conflict, and Adolescent Adjustment in Northern Ireland

Burgeoning evidence identifies the influence of fathers and, relatedly, fathers in the family context (e.g., family conflict), on adolescent adjustment. However, little is known about the significance of fathers’ presence in contexts of environmental risk. In a unique social-political context of economic and sociopolitical adversity, this study examined relations between adolescent adjustment, fathers’ presence, and family conflict in families in Belfast, Northern Ireland. Based on responses from 999 adolescents (M = 12.18 years; SD= 1.82) and their mothers, participating from 2006 to 2012, fathers’ presence was linked with reduced internalizing symptoms, and family conflict was related to both internalizing and externalizing problems. The discussion considers the implications for understanding family dynamics related to adolescent adjustment in contexts of environmental adversity

Re-evaluation of blood mercury, lead and cadmium concentrations in the Inuit population of Nunavik (Québec): a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Arctic populations are exposed to mercury, lead and cadmium through their traditional diet. Studies have however shown that cadmium exposure is most often attributable to tobacco smoking. The aim of this study is to examine the trends in mercury, lead and cadmium exposure between 1992 and 2004 in the Inuit population of Nunavik (Northern Québec, Canada) using the data obtained from two broad scale health surveys, and to identify sources of exposure in 2004.</p> <p>Methods</p> <p>In 2004, 917 adults aged between 18 and 74 were recruited in the 14 communities of Nunavik to participate to a broad scale health survey. Blood samples were collected and analysed for metals by inductively coupled plasma mass spectrometry, and dietary and life-style characteristics were documented by questionnaires. Results were compared with data obtained in 1992, where 492 people were recruited for a similar survey in the same population.</p> <p>Results</p> <p>Mean blood concentration of mercury was 51.2 nmol/L, which represent a 32% decrease (p < 0.001) between 1992 and 2004. Mercury blood concentrations were mainly explained by age (partial r²= 0.20; p < 0.0001), and the most important source of exposure to mercury was marine mammal meat consumption (partial r²= 0.04; p < 0.0001). In 2004, mean blood concentration of lead was 0.19 μmol/L and showed a 55% decrease since 1992. No strong associations were observed with any dietary source, and lead concentrations were mainly explained by age (partial r²= 0.20.; p < 0.001). Blood cadmium concentrations showed a 22% decrease (p < 0.001) between 1992 and 2004. Once stratified according to tobacco use, means varied between 5.3 nmol/L in never-smokers and 40.4 nmol/L in smokers. Blood cadmium concentrations were mainly associated with tobacco smoking (partial r²= 0.56; p < 0.0001), while consumption of caribou liver and kidney remain a minor source of cadmium exposure among never-smokers.</p> <p>Conclusion</p> <p>Important decreases in mercury, lead and cadmium exposure were observed. Mercury decrease could be explained by dietary changes and the ban of lead cartridges use likely contributed to the decrease in lead exposure. Blood cadmium concentrations remain high and, underscoring the need for intensive tobacco smoking prevention campaigns in the Nunavik population.</p