Non-sequential triple ionization in strong fields

We consider the final stage of triple ionization of atoms in a strong linearly polarized laser field. We propose that for intensities below the saturation value for triple ionization the process is dominated by the simultaneous escape of three electrons from a highly excited intermediate complex. We identify within a classical model two pathways to triple ionization, one with a triangular configuration of electrons and one with a more linear one. Both are saddles in phase space. A stability analysis indicates that the triangular configuration has the larger cross sections and should be the dominant one. Trajectory simulations within the dominant symmetry subspace reproduce the experimentally observed distribution of ion momenta parallel to the polarization axis.Comment: 9 pages, 8 figures, accepted for publication in Phys. Rev.

Exact Bayesian curve fitting and signal segmentation.

We consider regression models where the underlying functional relationship between the response and the explanatory variable is modeled as independent linear regressions on disjoint segments. We present an algorithm for perfect simulation from the posterior distribution of such a model, even allowing for an unknown number of segments and an unknown model order for the linear regressions within each segment. The algorithm is simple, can scale well to large data sets, and avoids the problem of diagnosing convergence that is present with Monte Carlo Markov Chain (MCMC) approaches to this problem. We demonstrate our algorithm on standard denoising problems, on a piecewise constant AR model, and on a speech segmentation problem

Preventive medical care in remote Aboriginal communities in the Northern Territory: a follow-up study of the impact of clinical guidelines, computerised recall and reminder systems, and audit and feedback

Background Interventions to improve delivery of preventive medical services have been shown to be effective in North America and the UK. However, there are few studies of the extent to which the impact of such interventions has been sustained, or of the impact of such interventions in disadvantaged populations or remote settings. This paper describes the trends in delivery of preventive medical services following a multifaceted intervention in remote community health centres in the Northern Territory of Australia. Methods The intervention comprised the development and dissemination of best practice guidelines supported by an electronic client register, recall and reminder systems and associated staff training, and audit and feedback. Clinical records in seven community health centres were audited at regular intervals against best practice guidelines over a period of three years, with feedback of audit findings to health centre staff and management. Results Levels of service delivery varied between services and between communities. There was an initial improvement in service levels for most services following the intervention, but improvements were in general not fully sustained over the three year period. Conclusions Improvements in service delivery are consistent with the international experience, although baseline and follow-up levels are in many cases higher than reported for comparable studies in North America and the UK. Sustainability of improvements may be achieved by institutionalisation of relevant work practices and enhanced health centre capacity

Gender Gap in Repartnering: The Role of Parental Status and Custodial Arrangements : Gender Gap in Repartnering

Objective: This study assesses whether parenthood influences repartnering for women and men and explores how repartnering is associated with parental status of the prospective partners. Background: Previous research has not demonstrated whether gender differences in repartnering are conditional on the presence of children. This study aims to better disentangle the specific gender differentials in repartnering probabilities conditional on parenthood and child custody status. Method: The analytical sample consists of 5,372 women and 3,375 men who reported at least one partnership dissolution in the British Understanding Society survey. Multilevel event history models with Markov Chain Monte Carlo simulations are used to estimate the probabilities of (a) finding a new partner and (b) finding a new childless partner or a new partner who has children. Results: The results suggest that mothers, and to a lesser extent fathers, are less likely to repartner than their childless counterparts. Among parents who have child custody, there emerges a distinct gender gap because mothers exhibit a significantly lower rate of repartnering than fathers. Finally, coresident single parents are relatively less likely to repartner with childless individuals, and single fathers more frequently form two-parent stepfamilies than do mothers. Conclusion: This suggests the presence of a gender divide in repartnering that is especially apparent when child custody is taken into account. The presence of children also reduces the possibility of forming unions with childless individuals

Furthering alternative cultures of valuation in higher education research

The value of higher education is often implicit or assumed in educational research. The underlying and antecedent premises that shape and influence debates about value remain unchallenged which perpetuates the dominant, but limiting, terms of the debate and fosters reductionism. I proceed on the premise that analyses of value are not self–supporting or self-referential but are embedded within prevailing cultures of valuation. I contend that challenging, and providing alternatives to, dominant narratives of higher education requires an appreciation of those cultures. I therefore highlight some of the existing cultures of valuation and their influence. I then propose Sayer’s concept of lay normativity as a culture of valuation and discuss how it translates into the practices of research into higher education, specifically the practice of analysis. I animate the discussion by detecting the presence of lay normativity in the evaluative space of the capability approach

Changes in Retinol-Binding Protein Concentrations and Thyroid Homeostasis with Nonoccupational Exposure to DDT

BACKGROUND: The insecticide dichlorodiphenyltrichloroethane (DDT) has been used for malaria vector control in the northern and eastern parts of the Vhembe District of Limpopo Province, South Africa, since 1945. Bioaccumulation of DDT raises concern because it reportedly affects thyroid function. OBJECTIVE: Our objective was to investigate the association between DDT uptake (as reflected in plasma concentrations) and thyroid homeostasis while considering related factors. METHODS: We compared dietary intake, serum retinol-binding protein (RBP), transthyretin (TTR) and albumin concentrations, and liver and thyroid function between cases with evidence of a body burden of DDT in the circulation (concentration of any DDT isomer ≥ 0.02 μg/g lipid; n = 278) and controls (concentration of all DDT isomers < 0.02 μg/g lipid; n = 40) in a cross-sectional study. Further analyses were performed to assess the relevance of changes in RBP status associated with DDT uptake. RESULTS: RBP concentrations below the reference range were more prevalent in cases (54% vs. 10% in controls; χ2 = 27.4; p < 0.001), which could not be explained by nutrient intake. We observed significantly lower thyroid hormone concentrations among cases (p ≤ 0.01). We also observed a significant linear trend for serum concentrations of free thyroxine and free triiodothyronine (p < 0.001) and a significant quadratic trend for serum thyroid-stimulating hormone (p = 0.025) and TTR (p < 0.001) across the control group and case groups with normal and relatively low RBP concentrations. Relatively low RBP concentrations were associated with significantly higher DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) isomer concentrations and with a higher DDE/DDT ratio (p ≤ 0.01), which signifies long-term exposure. Inadequate intake of vitamin A and zinc were observed in 84% and 58%, respectively, of the total study population. CONCLUSION: RBP concentrations appear to decrease in the presence of long-term DDT uptake, which may have deleterious effects on thyroid function and vitamin A nutritional status. This is of major concern in a population with poor vitamin A and zinc intake

The political process of constructing a sustainable London Olympics sports development legacy

This study attempts to develop a research agenda for understanding the process of constructing a sustainable Olympic sports development legacy. The research uses a social constructivist perspective to examine the link between the 2012 London Olympic Games and sustainable sports development. The first part of the paper provides justification for the study of sport policy processes using a constructivist lens. This is followed by a section which critically unpacks sustainable sports development drawing on Mosse’s (1998) ideas of process-oriented research and Searle’s conceptualisation of the construction of social reality. Searle’s (1995) concepts of the assignment of function, collective intentionality, collective rules, and human capacity to cope with the environment are considered in relation to the events and discourses emerging from the legacy vision(s) associated with the 2012 London Olympic Games. The paper concludes by proposing a framework for engaging in process oriented research and highlights key elements, research questions, and methodological issues. The proposed constructivist approach can be used to inform policy, practice, and research on sustainable Olympic sports development legacy

The Economic Resource Receipt of New Mothers

U.S. federal policies do not provide a universal social safety net of economic support for women during pregnancy or the immediate postpartum period but assume that employment and/or marriage will protect families from poverty. Yet even mothers with considerable human and marital capital may experience disruptions in employment, earnings, and family socioeconomic status postbirth. We use the National Survey of Families and Households to examine the economic resources that mothers with children ages 2 and younger receive postbirth, including employment, spouses, extended family and social network support, and public assistance. Results show that many new mothers receive resources postbirth. Marriage or postbirth employment does not protect new mothers and their families from poverty, but education, race, and the receipt of economic supports from social networks do

Recommendations for the surgical treatment of endometriosis. Part 2: deep endometriosis

Study question: How should surgery for endometriosis be performed? / Summary answer: This document provides recommendations covering technical aspects of different methods of surgery for deep endometriosis in women of reproductive age. / What is known already: Endometriosis is highly prevalent and often associated with severe symptoms. Yet compared to equally prevalent conditions it is poorly understood and a challenge to manage. Previously published guidelines have provided recommendations for (surgical) treatment of deep endometriosis, based on the best available evidence, but without technical information and details on how to best perform such treatment in order to be effective and safe. / Study, design, size, duration: A working group of the European Society for Gynaecological Endoscopy (ESGE), European Society of Human Reproduction and Embryology (ESHRE) and the World Endometriosis Society (WES) collaborated on writing recommendations on the practical aspects of surgery for treatment of deep endometriosis. / Participants, materials, setting, methods: This document focused on surgery for deep endometriosis, and is complementary to a previous document in this series focusing on endometrioma surgery. / Main results and the role of chance: The document presents general recommendations for surgery for deep endometriosis, starting from preoperative assessments and first steps of surgery. Different approaches for surgical treatment are discussed and are respective of location and extent of disease; uterosacral ligaments and rectovaginal septum with or without involvement of the rectum, urinary tract or extrapelvic endometriosis. In addition, recommendations are provided on the treatment of frozen pelvis and on hysterectomy as a treatment for deep endometriosis. / Limitations, reasons for caution: Owing to the limited evidence available, recommendations are mostly based on clinical expertise. Where available, references of relevant studies were added. / Wider implications of the findings: These recommendations complement previous guidelines on management of endometriosis and the recommendations for surgical treatment of ovarian endometrioma. / Study funding - Competing interest(s): The meetings of the working group were funded by ESGE, ESHRE and WES