Risk Parity Portfolio Optimization under Heavy-Tailed Returns and Time-Varying Volatility

Risk parity portfolio optimization, using expected shortfall as the risk measure, is investigated when asset returns are fat-tailed and heteroscedastic. The conditional return distribution is modeled by an elliptical multivariate generalized hyperbolic distribution, allowing for fast parameter estimation, via an expectation-maximization algorithm and a semi-closed form of the risk contributions. The efficient computation of non-Gaussian risk parity weights sidesteps the need for numerical simulations or Cornish-Fisher-type approximations. Accounting for fat-tailed returns, the risk parity allocation is less sensitive to volatility shocks, thereby generating lower portfolio turnover, in particular during market turmoils such as the global financial crisis. Although risk parity portfolios are surprisingly robust to the misuse of the Gaussian distribution, a more realistic model for conditional returns and time-varying volatilies can improve risk-adjusted returns, reduces turnover during periods of market stress and enables the use of a holistic risk model for portfolio and risk management

Maternal obesity has little effect on the immediate offspring but impacts on the next generation

Maternal obesity during pregnancy has been linked to an increased risk of obesity and cardiometabolic disease in the offspring, a phenomenon attributed to developmental programming. Programming effects may be transmissible across generations through both maternal and paternal inheritance, although the mechanisms remain unclear. Using a mouse model, we explored the effects of moderate maternal diet-induced obesity (DIO) on weight gain and glucose-insulin homeostasis in first-generation (F1) and second-generation offspring. DIO was associated with insulin resistance, hyperglycemia and dyslipidemia before pregnancy. Birth weight was reduced in female offspring of DIO mothers (by 6%, P = .039), and DIO offspring were heavier than controls at weaning (males by 47%, females by 27%), however there were no differences in glucose tolerance, plasma lipids, or hepatic gene expression at 6 months. Despite the relative lack of effects in the F1, we found clear fetal growth restriction and persistent metabolic changes in otherwise unmanipulated second-generation offspring with effects on birth weight, insulin levels, and hepatic gene expression that were transmitted through both maternal and paternal lines. This suggests that the consequences of the current dietary obesity epidemic may also have an impact on the descendants of obese individuals, even when the phenotype of the F1 appears largely unaffected

Users' perceptions of interprofessional collaborative care during their cancer journeys'.

Purpose: The study aimed to construct narratives of journeys that cancer patients and their families experience and to investigate participants' perceptions of related interagency collaboration spanning any engagements with the National Health Service (NHS); social services; local authority; voluntary; private and independent sectors. Methods: Using a qualitative design and focus groups the key facets of integrated care were explored with clients from a charity that focussed on cancer care. The 'talking wall' approach was adapted for use in the focus groups. Framework analysis was used to extrapolate the key themes. Results: Focus groups with 44 volunteers were conducted. Data included visual representations; textual comments and researcher reflections. The findings highlighted that the care received by many of the volunteers was variable with reports of very satisfactory experiences and also poor experiences. Respondents expected collaborative care and only in its absence was there cognisance of its importance in streamlining services for their care journeys. The role for the voluntary and independent sectors was significant. Conclusions and Implications for cancer survivors: Effective interprofessional collaboration was perceived to ease the pain of the cancer journey. The different yet interlocking interventions and support from statutory and voluntary agencies is clearly a holistic approach that is appreciated by the patient. Care management for cancer patients is complex in its nature necessitating professionals to work across organisational boundaries and achieve the best outcomes for long term care management. When professionals do not do this effectively cancer survivors and their carers are often left to 'join up' the services themselves and there is greater reliance on voluntary organisations

Building Capacity in the Zambian Mental Health Workforce through Engaging College Educators: Evaluation of a Development Partnership in Higher Education (DelPHe) project

yesBetween 2008 and 2011 academic teaching staff from Leeds Beckett University (UK) and Chainama Hills College of Health Sciences (Zambia) worked together on a Development Partnership in Higher Education (DelPHe) project funded by the Department for International Development (DFID) via the British Council. The partnership focused on “up-scaling” the provision of mental health education which was intended to build capacity through the delivery of a range of workshops for health educators at Chainama College, Lusaka. The project was evaluated on completion using small focus group discussions (FGDs), so educators could feedback on their experience of the workshops and discuss the impact of learning into their teaching practice. This chapter discusses the challenges of scaling up the mental health workforce in Zambia; the rationale for the content and delivery style of workshops with the health educators and finally presents and critically discusses the evaluation findings.Department for International Development (DFID) via the British Counci

Glucocorticoid-Mediated Inhibition of Angiogenic Changes in Human Endothelial Cells Is Not Caused by Reductions in Cell Proliferation or Migration

Glucocorticoid-mediated inhibition of angiogenesis is important in physiology, pathophysiology and therapy. However, the mechanisms through which glucocorticoids inhibit growth of new blood vessels have not been established. This study addresses the hypothesis that physiological levels of glucocorticoids inhibit angiogenesis by directly preventing tube formation by endothelial cells.Cultured human umbilical vein (HUVEC) and aortic (HAoEC) endothelial cells were used to determine the influence of glucocorticoids on tube-like structure (TLS) formation, and on cellular proliferation (5-bromo-2'-deoxyuridine (BrdU) incorporation), viability (ATP production) and migration (Boyden chambers). Dexamethasone or cortisol (at physiological concentrations) inhibited both basal and prostaglandin F(2α) (PGF(2α))-induced and vascular endothelial growth factor (VEGF) stimulated TLS formation in endothelial cells (ECs) cultured on Matrigel, effects which were blocked with the glucocorticoid receptor antagonist RU38486. Glucocorticoids had no effect on EC viability, migration or proliferation. Time-lapse imaging showed that cortisol blocked VEGF-stimulated cytoskeletal reorganisation and initialisation of tube formation. Real time PCR suggested that increased expression of thrombospodin-1 contributed to glucocorticoid-mediated inhibition of TLS formation.We conclude that glucocorticoids interact directly with glucocorticoid receptors on vascular ECs to inhibit TLS formation. This action, which was conserved in ECs from two distinct vascular territories, was due to alterations in cell morphology rather than inhibition of EC viability, migration or proliferation and may be mediated in part by induction of thrombospodin-1. These findings provide important insights into the anti-angiogenic action of endogenous glucocorticoids in health and disease

Electrochemical characterization and regeneration of sulfur poisoned Pt catalysts in aqueous media

Understanding the poisoning and recovery of precious metal catalysts is greatly relevant for the chemical industry dealing with the synthesis of organic compounds. For example, hydrogenation reactions typically use platinum catalysts and sulfuric acid media, leading to poisoning by sulfur-containing species. In this work, we have applied electrochemical methods to understand the status and recovery of Pt catalysts by studying the electro-oxidation of a family of sulfur-containing species adsorbed at several types of Pt electrodes: (i) polycrystalline Pt foil; (ii) Pt single-crystal electrodes; and (iii) Pt nanoparticles supported on Vulcan carbon. The results obtained from polycrystalline Pt electrodes and Pt nanoparticles supported on Vulcan carbon demonstrate that all sulfur-containing species with different oxidation states (2-, 3+ and 4+) lead to the poisoning of Pt active sites. X-ray photoelectron spectroscopy (XPS) analysis was employed to elucidate the chemical state of sulfur species during the recovery process. The degree of poisoning decreased with increased sulfur oxidation state, while the rate of regeneration of the Pt surfaces generally increases with the oxidation state of the sulfur species. Finally, the use of Pt single-crystal electrodes reveals the surface-structure sensitivity of the oxidation of the sulfur species. This information could be useful in designing catalysts that are less susceptible to poisoning and/or more easily regenerated. These studies demonstrate voltammetry to be a powerful method for assessing the status of platinum surfaces and for recovering catalyst activity, such that electrochemical methods could find applications as sensors in catalysis and for catalyst recovery in-situ

Quality of life in Type 1 (insulin-dependent) diabetic patients prior to and after pancreas and kidney transplantation in relation to organ function

Improvement of the quality of life in Type 1 (insulin-dependent) diabetic patients with severe late complications is one of the main goals of pancreas and/or kidney grafting. To assess the influences of these treatment modalities on the different aspects of the quality of life a cross-sectional study in 157 patients was conducted. They were categorized into patients pre-transplant without dialysis (n=29; Group A), pre-transplant under dialysis (n=44; Group B), post-transplant with pancreas and kidney functioning (n=31; Group C), post-transplant with functioning kidney, but insulin therapy (n=29; Group D), post-transplant under dialysis and insulin therapy again (n=15; Group E) and patients after single pancreas transplantation and rejection, with good renal function, but insulin therapy (n=9; Group F). All patients answered a mailed, self-administered questionnaire (217 questions) consisting of a broad spectrum of rehabilitation criteria. The results indicate a better quality of life in Groups C and D as compared to the other groups. In general the scores are highest in C, but without any significant difference to D. Impressive significant differences between C or D and the other groups were found especially in their satisfaction with physical capacity, leisure-time activities or the overall quality of life. The satisfaction with the latter is highest in C (mean±SEM: 4.0±0.2 on a 1 to 5-rating scale; significantly different from A: 3.1±0.1, B: 2.7±0.2 and E: 2.6±0.3; p<0.01), followed by D (3.8±0.2; significantly different from B and E; p<0.01). Group F shows a mean of 3.1±0.4, which is not significantly different from C. The percentages of patients in each group, who are not working: A: 38 %, B: 64 %, C: 74 %, D: 66 %, E: 87 % and F: 78 % indicate that there is no marked improvement in the vocational situation after successful grafting