340 research outputs found
Brueckner-Goldstone quantum Monte Carlo for correlation energies and quasiparticle energy bands of one-dimensional solids
A quantum Monte Carlo method that combines the second-order many-body perturbation theory and Monte Carlo (MC) integration has been developed for correlation and correlation-corrected (quasiparticle) energy bands of one-dimensional solids. The sum-of-product expressions of correlation energy and self-energy are transformed, with the aid of a Laplace transform, into high-dimensional integrals, which are subject to a highly scalable MC integration with the Metropolis algorithm for importance sampling. The method can compute correlation energies of polyacetylene and polyethylene within a few mEh and quasiparticle energy bands within a few tenths of an eV. It does not suffer from the fermion sign problem and its description can be systematically improved by raising the perturbation order.open0
East-West divide: temperature and land cover drive spatial variation of Toxoplasma gondii infection in Eurasian otters (Lutra lutra) from England and Wales
Toxoplasma gondii, a zoonotic parasite of global importance, infects all endothermic vertebrates, with extensive health implications. The prevalence of this parasite is seldom monitored in wildlife. Here, a semi-aquatic species, the Eurasian otter (Lutra lutra) was used as a model to assess the potential effect of climate, land cover and biotic factors on T. gondii seroprevalence in British wildlife. The Sabin–Feldman cytoplasm-modifying dye test identified T. gondii antibodies in 25·5% of blood samples from otters found dead, mainly as road kill, in England and Wales, between 2004 and 2010. Otters in the east of England were more likely to be infected with T. gondii than those in western regions. Land cover and temperature are key determinants of T. gondii infection risk, with more infection in arable areas and lower infection where temperatures are higher. The probability of T. gondii infection increased with host age, reflecting cumulative exposure with time, but there was no association between T. gondii seroprevalence and cause of host death
Stochastic evaluation of second-order Dyson self-energies
A stochastic method is proposed that evaluates the second-order perturbation corrections to the Dyson self-energies of a molecule (i.e., quasiparticle energies or correlated ionization potentials and electron affinities) directly and not as small differences between two large, noisy quantities. With the aid of a Laplace transform, the usual sum-of-integral expressions of the second-order self-energy in many-body Greens function theory are rewritten into a sum of just four 13-dimensional integrals, 12-dimensional parts of which are evaluated by Monte Carlo integration. Efficient importance sampling is achieved with the Metropolis algorithm and a 12-dimensional weight function that is analytically integrable, is positive everywhere, and cancels all the singularities in the integrands exactly and analytically. The quasiparticle energies of small molecules have been reproduced within a few mEh of the correct values with 108 Monte Carlo steps. Linear-to-quadratic scaling of the size dependence of computational cost is demonstrated even for these small molecules.open9
Working with Children with Learning Disabilities and/or who Communicate Non-verbally: Research experiences and their implications for social work education, increased participation and social inclusion
Social exclusion, although much debated in the UK, frequently focuses on children as a key 'at risk' group. However, some groups, such as disabled children, receive less consideration. Similarly, despite both UK and international policy and guidance encouraging the involvement of disabled children and their right to participate in decision-making arenas, they are frequently denied this right. UK based evidence suggests that disabled children's participation lags behind that of their non-disabled peers, often due to social work practitioners' lack of skills, expertise and knowledge on how to facilitate participation. The exclusion of disabled children from decision-making in social care processes echoes their exclusion from participation in society. This paper seeks to begin to address this situation, and to provide some examples of tools that social work educators can introduce into pre- and post-qualifying training programmes, as well as in-service training. The paper draws on the experiences of researchers using non-traditional qualitative research methods, especially non-verbal methods, and describes two research projects, focusing on the methods employed to communicate with and involve disabled children, the barriers encountered and lessons learnt. Some of the ways in which these methods of communication can inform social work education are explored alongside wider issues of how and if increased communication can facilitate greater social inclusion
Race Obsession-Avoidance Paradox: A Model for Multicultural Training in Counselor Education
The ability to discuss race-related issues is critical to multicultural competence. Counselor educators who address race-related issues in the classroom cite student resistance as a challenge to competency development. The Race Obsession-Avoidance Paradox (ROAParadox) identifies juxtaposed obsession and avoidance about race as a cultural phenomenon. The ROAParadox model was applied in a multicultural counseling course as a strategy for educating counseling students. Teaching scenarios illustrate the use of this model as a strategy to facilitate discussions on race relations and racism. Student responses and implications for teaching applications are provided along with recommendations for future research
Race Obsession-Avoidance Paradox: A Model for Multicultural Training in Counselor Education
The ability to discuss race-related issues is critical to multicultural competence. Counselor educators who address race-related issues in the classroom cite student resistance as a challenge to competency development. The Race Obsession-Avoidance Paradox (ROAParadox) identifies juxtaposed obsession and avoidance about race as a cultural phenomenon. The ROAParadox model was applied in a multicultural counseling course as a strategy for educating counseling students. Teaching scenarios illustrate the use of this model as a strategy to facilitate discussions on race relations and racism. Student responses and implications for teaching applications are provided along with recommendations for future research
Discriminación por razón de género y negociación colectiva tras la ley 3/2012
Este artículo describe y analiza la configuración jurídica del convenio colectivo como fuente reguladora y ga-rantista del derecho de igualdad y no dis-criminación por razón de género, tanto con carácter general como en el ámbito específico del acceso al empleo, formación y promoción en el trabajo y en las más relevantes condiciones en las relaciones laborales. A tal fin, y a partir de la doctrina establecida por la jurisprudencia constitucional, se estudian las causas de la desigualdad y las categorías que permiten una fundamentación razonable y objetiva para lograr la igualdad material. También se aportan datos cuantitativos acerca de la influencia de la Ley Orgánica 3/2007 en el régimen de los convenios convenios colectivos en esta materia.This paper work de-scribes and analyses the collective agree-ments legal configuration as regulating and guarantor source of the equality's right and no discrimination because of the sex, as much in general terms as in the specific field of accessing to a job, training and advance-ment in the job and in the main conditions in the labour relationships. According the established doctrine by the constitutional sentences, we study the inequality causes and the categories which give a reasonable and factual basis to reach a material equality. In addition, this work also provides quanti-tative facts about the influence of Organic Law 3/2007 in the collective agreements regime in this matte
Emerging pharmacotherapy of tinnitus
Tinnitus, the perception of sound in the absence of an auditory stimulus, is perceived by about 1 in 10 adults, and for at least 1 in 100, tinnitus severely affects their quality of life. Because tinnitus is frequently associated with irritability, agitation, stress, insomnia, anxiety and depression, the social and economic burdens of tinnitus can be enormous. No curative treatments are available. However, tinnitus symptoms can be alleviated to some extent. The most widespread management therapies consist of auditory stimulation and cognitive behavioral treatment, aiming at improving habituation and coping strategies. Available clinical trials vary in methodological rigor and have been performed for a considerable number of different drugs. None of the investigated drugs have demonstrated providing replicable long-term reduction of tinnitus impact in the majority of patients in excess of placebo effects. Accordingly, there are no FDA or European Medicines Agency approved drugs for the treatment of tinnitus. However, in spite of the lack of evidence, a large variety of different compounds are prescribed off-label. Therefore, more effective pharmacotherapies for this huge and still growing market are desperately needed and even a drug that produces only a small but significant effect would have an enormous therapeutic impact. This review describes current and emerging pharmacotherapies with current difficulties and limitations. In addition, it provides an estimate of the tinnitus market. Finally, it describes recent advances in the tinnitus field which may help overcome obstacles faced in the pharmacological treatment of tinnitus. These include incomplete knowledge of tinnitus pathophysiology, lack of well-established animal models, heterogeneity of different forms of tinnitus, difficulties in tinnitus assessment and outcome measurement and variability in clinical trial methodology. © 2009 Informa UK Ltd.Fil: Langguth, Berthold. Universitat Regensburg; AlemaniaFil: Salvi, Richard. State University of New York; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin
The Impact of Rising Ocean Acidification Levels on Fish Migration
Ocean acidification, a direct consequence of increased carbon dioxide (CO2)emissions, has emerged as a critical area of concern within the scientific community.The world's oceans absorb approximately one-third of human-caused CO2 emissions,leading to chemical reactions that reduce seawater pH, carbonate ion concentration,and saturation states of biologically important calcium carbonate minerals. Thisprocess, known as ocean acidification, has far-reaching implications for marineecosystems, particularly for marine organisms such as fish, whose migratory patternsare integral to the health and function of these ecosystems.
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