On the q-deformation of the NJL model

Using a q-deformed fermionic algebra we perform explicitly a deformation of the Nambu-Jona-Lasinio (NJL) Hamiltonian. In the Bogoliubov-Valatin approach we obtain the deformed version of the functional for the total energy, which is minimized to obtain the corresponding gap equation. The breaking of chiral symmetry and its restoration in the limit $q \to 0$ are then discussed.Comment: 5 eps figure

Black Hole Formation with an Interacting Vacuum Energy Density

We discuss the gravitational collapse of a spherically symmetric massive core of a star in which the fluid component is interacting with a growing vacuum energy density. The influence of the variable vacuum in the collapsing core is quantified by a phenomenological \beta-parameter as predicted by dimensional arguments and the renormalization group approach. For all reasonable values of this free parameter, we find that the vacuum energy density increases the collapsing time but it cannot prevent the formation of a singular point. However, the nature of the singularity depends on the values of \beta. In the radiation case, a trapped surface is formed for \beta<1/2 whereas for \beta>1/2, a naked singularity is developed. In general, the critical value is \beta=1-2/3(1+\omega), where the \omega-parameter describes the equation of state of the fluid component.Comment: 9 pages, 8 figure

An analysis of media reporting on the closure of freestanding midwifery units in England

PROBLEM: Despite clinical guidelines and policy promoting choice of place of birth, 14 Freestanding Midwifery Units were closed between 2008 and 2015, closures justified by low use and financial constraints. BACKGROUND: The Birthplace in England Programme found that freestanding midwifery units provided the most cost-effective birthplace for women at low risk of complications. Women planning birth in a freestanding unit were less likely to experience interventions than those planning obstetric unit birth, with no difference in outcomes for babies. METHODS: This paper uses an interpretative technique developed for policy analysis to explore the representation of these closures in 191 news articles, to explore the public climate in which they occurred. FINDINGS AND DISCUSSION: The articles focussed on underuse by women and financial constraints on services. Despite the inclusion of service user voices, the power of framing was held by service managers and commissioners. The analysis exposed how neoliberalist and austerity policies has privileged representation of individual consumer choice and market-driven provision as drivers of changes in health services. This normative framing makes the reasons given for closure as hard to refute and cultural norms persist that birth is safest in an obstetric setting, despite evidence to the contrary. CONCLUSION: The rise of neoliberalism and austerity in contemporary Britain has influenced the reform of maternity services, in particular the closure of midwifery units. Justifications given for closure silence other narratives, predominantly from service users, that attempt to present women's choice in terms of rights and a social model of care

Raising awareness of climate change causes? Cross-national evidence for the normalization of societal risk perception of climate change

Increasing the awareness of climate change causes is often considered the key to public support of mitigation and adaptation policies. However, higher awareness might not always relate to higher risk perceptions. Previous research suggests that a process of risk normalization might occur, wherein individuals more exposed and aware of hazards minimize their risk perception to psychologically cope with hazards. This study elaborates on and expands this research, by conducting multilevel analyses on more recent data from the International Social Survey Programme from 33 countries (N = 46,221). Results show that in countries with higher carbon dioxide emissions, where people are more exposed to the activities and technologies related to climate change, individuals tend to have lower societal risk perceptions of climate change due to their higher awareness of climate change causes. New insight is provided, as results confirm this effect of risk normalization after controlling for the country socioeconomic context and individual-level covariates (gender, age, education, political orientation, place of living). Of most relevance, results further illustrate that this effect is moderated by the environmental concern of individuals.info:eu-repo/semantics/acceptedVersio

The EURAGE Group: examining ageing and ageism in context through the European Social Survey

The experience of ageism has important health implications for older adults. Yet, to date very little is known about the interplay of psychological and contextual factors in fostering ageism. This paper presents research conducted by EURAGE (European Research Group on Attitudes to Age) which aims to study the experience of ageism and age prejudice from a multilevel perspective. EURAGE is an international group of researchers with members from the Health for All group at the Centre for Research and Social Intervention (CIS-IUL, Portugal) and the Centre for the Study of Group Processes at the University of Kent (UK). Members of EURAGE designed the Experiences and Expressions of Ageism Module in Round 4 of the European Social Survey (ESS) which is perfectly suited for multilevel analyses. The multi-level approach is briefly outlined as well as some of EURAGE’s key findings to date. Implications for policy and social interventions are briefly discussed.info:eu-repo/semantics/acceptedVersio

Clustering, Angular Size and Dark Energy

The influence of dark matter inhomogeneities on the angular size-redshift test is investigated for a large class of flat cosmological models driven by dark energy plus a cold dark matter component (XCDM model). The results are presented in two steps. First, the mass inhomogeneities are modeled by a generalized Zeldovich-Kantowski-Dyer-Roeder (ZKDR) distance which is characterized by a smoothness parameter $\alpha(z)$ and a power index $\gamma$, and, second, we provide a statistical analysis to angular size data for a large sample of milliarcsecond compact radio sources. As a general result, we have found that the $\alpha$ parameter is totally unconstrained by this sample of angular diameter data.Comment: 9 pages, 7 figures, accepted in Physical Review

Sociabilidade das especies florestais da caatinga em Santa Maria da Boa Vista,PE.

O trabalho foi executado na Fazenda Canaa, municipio de Santa Maria da Boa Vista, PE, com o objetivo de determinar o grau de afinidade entre as especies da caatinga e a importancia das mesmas, para fornecer subsidios tecnicos e eventuais programas de manejo, de formacao de povoamentos heterogeneos e de enriquecimento da comunidade vegetal com essencias de maior valor economico madeireiro. Avaliou-se a composicao floristica quanto a frequencia, densidade e dominancia. A similaridade entre as parcelas e a associacao de especies foram analisadas pelo Coeficiente de Jaccard. Os resultados obtidos permitiram concluir que a vegetacao e caracterizada pela presenca do angico (Anademanthera macrocarpa), jurema-preta (Mimosa hostilis), jurema-vermelha (Mimosa sp), manicoba-brava (Manihot sp) e pau-piranha (Pisonia sp), sendo essas especies mais frequents; o angico e a especie dominante, sendo a mais explorada. Rama-de-boi (Acacia piauhiensis) e espinheiro (Pithecellobium viridiflorium) apresentam alto indice de associacao, permitindo portanto aventar a possiblidade do seu uso em consorcio