138 research outputs found
Analysis of fragment yield ratios in the nuclear phase transition
The critical phenomena of the liquid-gas phase transition has been
investigated in the reactions 78,86Kr+58,64Ni at beam energy of 35 MeV/nucleon
using the Landau free energy approach with isospin asymmetry as an order
parameter. Fits to the free energy of fragments showed three minima suggesting
the system to be in the regime of a first order phase transition. The relation
m =-{\partial}F/{\partial}H, which defines the order parameter and its
conjugate field H, has been experimentally verified from the linear dependence
of the mirror nuclei yield ratio data, on the isospin asymmetry of the source.
The slope parameter, which is a measure of the distance from a critical
temperature, showed a systematic decrease with increasing excitation energy of
the source. Within the framework of the Landau free energy approach, isoscaling
provided similar results as obtained from the analysis of mirror nuclei yield
ratio data. We show that the external field is primarily related to the minimum
of the free energy, which implies a modification of the source concentration
\Delta used in isospin studies
Analysis of fragment yield ratios in the nuclear phase transition
The critical phenomena of the liquid-gas phase transition has been
investigated in the reactions 78,86Kr+58,64Ni at beam energy of 35 MeV/nucleon
using the Landau free energy approach with isospin asymmetry as an order
parameter. Fits to the free energy of fragments showed three minima suggesting
the system to be in the regime of a first order phase transition. The relation
m =-{\partial}F/{\partial}H, which defines the order parameter and its
conjugate field H, has been experimentally verified from the linear dependence
of the mirror nuclei yield ratio data, on the isospin asymmetry of the source.
The slope parameter, which is a measure of the distance from a critical
temperature, showed a systematic decrease with increasing excitation energy of
the source. Within the framework of the Landau free energy approach, isoscaling
provided similar results as obtained from the analysis of mirror nuclei yield
ratio data. We show that the external field is primarily related to the minimum
of the free energy, which implies a modification of the source concentration
\Delta used in isospin studies
Blood lead, cadmium and mercury among children from urban, industrial and rural areas of Fez Boulemane Region (Morocco): Relevant factors and early renal effects
Objectives: To describe blood lead (Pb-B), cadmium (Cd-B) and mercury (Hg-B) levels in children living in urban, industrial and rural areas in Fez city (north of Morocco) and to identify the determinants and some renal effects of exposure. Material and Methods: The study was conducted from June 2007 to January 2008 in 209 school children (113 girls, 96 boys), aged 6-12 years, from urban, industrial and rural areas in Fez city. Interview and questionnaires data were obtained. Blood and urinary samples were analyzed. Results: The mean of blood lead levels (Pb-B) in our population was 55.53 μg/l (range: 7.5-231.1 μg/l). Children from the urban area had higher blood lead levels (BLLs) mean (82.36 μg/l) than children from industrial and rural areas (48.23 and 35.99 μg/l, respectively); with no significant difference between boys and girls. BLLs were associated with traffic intensity, passive smoking and infancy in the urban area. The mean of blood cadmium levels (BCLs) was 0.22 μg/l (range: 0.06-0.68 μg/l), with no difference between various areas. Rural boys had higher BCLs mean than rural girls, but no gender influence was noticed in the other areas. BCLs were associated with the number of cigarettes smoked at children's homes. The blood mercury levels (BMLs) mean was 0.49 μg/l (range: 0.01-5.31 μg/l). The BMLs mean was higher in urban and industrial areas than in the rural area with no gender-related difference. BMLs were associated with amalgam fillings and infancy in the urban area. About 8% of the children had BLLs ≥ 100 μg/l particularly in the urban area, microalbuminuria and a decrease in height were noticed in girls from the inner city of Fez and that can be related to high BLLs (89.45 μg/l). Conclusions: There is a need to control and regulate potential sources of contamination by these trace elements in children; particularly for lead
Towards an appreciation of ethics in social enterprise business models
How can a critical analysis of entrepreneurial intention inform an appreciation of ethics in social enterprise business models? In answering this question, we consider the ethical commitments that inform entrepreneurial action (inputs) and the hybrid organisations that emerge out of these commitments and actions (outputs). Ethical theory can be a useful way to re-orient the field of social enterprise so that it is more critical of bureaucratic (charitable) and market-driven (business) enterprises connected to neo-liberal doctrine. Social enterprise hybrid business models are therefore reframed as outcomes of both ethical and entrepreneurial intentions. We challenge the dominant conceptualisation of social enterprise as a hybrid blend of mission and market (purpose-versus-resource) by reframing hybridity in terms of the moral choice of economic system (redistribution, reciprocity and market) and social value orientation (personal, mutual or public benefit). We deconstruct the political foundations of charitable trading activities (CTAs), co-operative and mutual enterprises (CMEs) and socially responsible businesses (SRBs) by examining the rationalities (formal, social and substantive) and ethical commitments (utilitarian, communitarian, pragmatic) that underpin them. Whilst conceptual modelling of social enterprise is not new, this paper contributes to knowledge by developing a theory of social enterprise ethics based on the moral/political choices that are made by entrepreneurs (knowingly and unknowingly) when choosing between systems of economic exchange and social value orientation, then expressing it through a legal form
Growth And The Growth Hormone-Insulin Like Growth Factor 1 Axis In Children With Chronic Inflammation:Current Evidence, Gaps In Knowledge And Future Directions
Growth failure is frequently encountered in children with chronic inflammatory conditions like juvenile idiopathic arthritis, inflammatory bowel disease and cystic fibrosis. Delayed puberty and attenuated pubertal growth spurt is often seen during adolescence. The underlying inflammatory state mediated by pro-inflammatory cytokines, prolonged use of glucocorticoid and suboptimal nutrition contribute to growth failure and pubertal abnormalities. These factors can impair growth by their effects on the growth hormone-insulin like growth factor axis and also directly at the level of the growth plate via alterations in chondrogenesis and local growth factor signaling. Recent studies on the impact of cytokines and glucocorticoid on the growth plate studies further advanced our understanding of growth failure in chronic disease and provided a biological rationale of growth promotion. Targeting cytokines using biologic therapy may lead to improvement of growth in some of these children but approximately one third continue to grow slowly. There is increasing evidence that the use of relatively high dose recombinant human growth hormone may lead to partial catch up growth in chronic inflammatory conditions, although long term follow-up data is currently limited. In this review, we comprehensively review the growth abnormalities in children with juvenile idiopathic arthritis, inflammatory bowel disease and cystic fibrosis, systemic abnormalities of the growth hormone-insulin like growth factor axis and growth plate perturbations. We also systematically reviewed all the current published studies of recombinant human growth hormone in these conditions and discuss the role of recombinant human insulin like growth factor-1
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