Mean-Motion Resonances of High Order in Extrasolar Planetary Systems

Many multi-planet systems have been discovered in recent years. Some of them are in mean-motion resonances (MMR). Planet formation theory was successful in explaining the formation of 2:1, 3:1 and other low resonances as a result of convergent migration. However, higher order resonances require high initial orbital eccentricities in order to be formed by this process and these are in general unexpected in a dissipative disk. We present a way of generating large initial eccentricities using additional planets. This procedure allows us to form high order MMRs and predict new planets using a genetic N-body code.Comment: To appear in Proceedings: Extrasolar Planets in Multi-body Systems: Theory and Observations; Editors K. Gozdziewski, A. Niedzielski and J. Schneider; 5 pages, 2 figures

Evaluating and developing an information literacy programme for MBA students

Massey University has the longest continually-running Executive MBA programme in New Zealand which is specifically designed for managers who have substantial professional and managerial work experience (Massey University, 2016). Studying part time over 25 months, students learn how to be successful in senior leadership roles in the public or private sector. Business librarians at Massey University have been involved for more than 15 years in delivering information literacy sessions for this programme during their orientation weekend. This research provides a case study focusing on evaluating the “one-shot” library instruction approach used for 2015 and 2016 cohorts. Survey data supports findings of other studies that as students transition to postgraduate study, embedded and discipline specific library support is needed.falsePublishe

The Natsal-SF measure of sexual function: comparison of three scoring methods

The Natsal-SF is a psychometrically-validated measure of sexual function for use in community health surveys, derived from 17 questions reflecting three components of sexual function. Scoring requires knowledge of complex statistical modelling and, given the methodological complexities, we assess the validity of two simplified scoring methods calculated using the factor loadings produced when originally modelling the Natsal-SF items. Method 1 uses these factor loadings to three decimal places while method 2 assigns whole numbers to each item based on the factor loadings. Scores from these simplified methods are compared to the original score using correlation coefficients, by comparing the distributions, and the scores of each method in a linear regression model with key variables. We found scores from the simplified methods both correlate highly with the original score, and the distributions of scores closely match. The simplified methods result in different regression coefficients for gender and relationship context, but estimate the coefficients of all other variables similarly to the original method. While the Natsal-SF should ideally be scored using latent variable modelling, the simplified methods perform well so can be used in similar contexts, increasing the utility of the Natsal-SF and enabling future studies to measure sexual function more comprehensively

What factors are associated with reporting lacking interest in sex and how do these vary by gender? Findings from the third British national survey of sexual attitudes and lifestyles

OBJECTIVES: To investigate factors associated with reporting lacking interest in sex and how these vary by gender. SETTING: British general population. DESIGN: Complex survey analyses of data collected for a cross-sectional probability sample survey, undertaken 2010-2012, specifically logistic regression to calculate age-adjusted OR (AOR) to identify associated factors. PARTICIPANTS: 4839 men and 6669 women aged 16-74 years who reported ≥1 sexual partner (opposite-sex or same-sex) in the past year for the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). MAIN OUTCOME MEASURE: Lacking interest in sex for ≥3 months in the past year. RESULTS: Overall, 15.0% (13.9-16.2) of men and 34.2% (32.8-35.5) of women reported lacking interest in sex. This was associated with age and physical and mental health for both men and women, including self-reported general health and current depression. Lacking interest in sex was more prevalent among men and women reporting sexually transmitted infection diagnoses (ever), non-volitional sex (ever) and holding sexual attitudes related to normative expectations about sex. Some gender similarities in associated relationship and family-related factors were evident, including partner having had sexual difficulties in the last year (men: AOR 1.41 (1.07-1.86); women: AOR 1.60 (1.32-1.94)), not feeling emotionally close to partner during sex (men: 3.74 (1.76-7.93); women: 4.80 (2.99-7.69) and ease of talking about sex (men: 1.53 (1.23-1.90);women: 2.06 (1.77-2.39)). Among women only, lack of interest in sex was higher among those in a relationship of >1 year in duration and those not sharing the same level of interest (4.57 (3.87-5.38)) or preferences (2.91 (2.22-3.83)) with a partner. CONCLUSIONS: Both gender similarities and differences were found in factors associated with lacking interest in sex, with the most marked differences in relation to some relationship variables. Findings highlight the need to assess, and if appropriate, treat lacking interest in sex in a holistic and relationship-specific way

Investigating the relationship between substance use and sexual behaviour in young people in Britain: findings from a national probability survey.

BACKGROUND: Health risk behaviours are prominent in late adolescence and young adulthood, yet UK population-level research examining the relationship between drug or alcohol use and sexual health and behaviour among young people is scarce, despite public health calls for an integrated approach to health improvement. Our objective was to further our understanding of the scale of and nature of any such relationship, using contemporary data from Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). METHODS: Analyses of data from Natsal-3, a stratified probability survey of 15 162 men and women (3869 aged 16-24 years), undertaken in 2010-2012, using computer-assisted personal interviewing, were carried out. Logistic regression was used to explore associations between reporting (1) frequent binge drinking (≥weekly), (2) recent drug use (within past 4 weeks) or (3) multiple (both types of) substance use, and key sexual risk behaviours and adverse sexual health outcomes. We then examined the sociodemographic profile, health behaviours and attitudes reported by 'risky' young people, defined as those reporting ≥1 type of substance use plus non-condom use at first sex with ≥1 new partner(s), last year. RESULTS: Men and women reporting frequent binge drinking or recent drug use were more likely to report: unprotected first sex with ≥1 new partner(s), last year; first sex with their last partner after only recently meeting; emergency contraception use (last year) and sexually transmitted infection diagnosis/es (past 5 years). Associations with sexual risk were frequently stronger for those reporting multiple substance use, particularly among men. The profile of 'risky' young people differed from that of other 16-24 years old. CONCLUSIONS: In this nationally representative study, substance use was strongly associated with sexual risk and adverse sexual health outcomes among young people. Qualitative or event-level research is needed to examine the context and motivations behind these associations to inform joined-up interventions to address these inter-related behaviours

Estimating the Prevalence of Sexual Function Problems: The Impact of Morbidity Criteria

Establishing the clinical significance of symptoms of sexual dysfunction is challenging. To address this, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) introduced two new morbidity criteria (duration and symptom severity) to the existing criteria of distress. This study sought to establish the impact of these three criteria on the population prevalence of sexual function problems. The data come from a national probability survey (Natsal-3) and are based on 11,509 male and female participants aged 16-74, reporting at least one sexual partner in the past year. The key outcomes were: proportion of individuals reporting proxy measures of DSM-5 problems, and the proportion of those meeting morbidity criteria. We found that among sexually active men, the prevalence of reporting one or more of four specific sexual problems was 38.2%, but 4.2% after applying the three morbidity criteria; corresponding figures for women reporting one or more of three specific sexual problems, were 22.8% and 3.6%. Just over a third of men and women reporting a problem meeting all three morbidity criteria had sought help in the last year. We conclude that the DSM-5 morbidity criteria impose a focus on clinically significant symptoms

A transcriptomic snapshot of early molecular communication between Pasteuria penetrans and Meloidogyne incognita

© The Author(s). 2018Background: Southern root-knot nematode Meloidogyne incognita (Kofoid and White, 1919), Chitwood, 1949 is a key pest of agricultural crops. Pasteuria penetrans is a hyperparasitic bacterium capable of suppressing the nematode reproduction, and represents a typical coevolved pathogen-hyperparasite system. Attachment of Pasteuria endospores to the cuticle of second-stage nematode juveniles is the first and pivotal step in the bacterial infection. RNA-Seq was used to understand the early transcriptional response of the root-knot nematode at 8 h post Pasteuria endospore attachment. Results: A total of 52,485 transcripts were assembled from the high quality (HQ) reads, out of which 582 transcripts were found differentially expressed in the Pasteuria endospore encumbered J2 s, of which 229 were up-regulated and 353 were down-regulated. Pasteuria infection caused a suppression of the protein synthesis machinery of the nematode. Several of the differentially expressed transcripts were putatively involved in nematode innate immunity, signaling, stress responses, endospore attachment process and post-attachment behavioral modification of the juveniles. The expression profiles of fifteen selected transcripts were validated to be true by the qRT PCR. RNAi based silencing of transcripts coding for fructose bisphosphate aldolase and glucosyl transferase caused a reduction in endospore attachment as compared to the controls, whereas, silencing of aspartic protease and ubiquitin coding transcripts resulted in higher incidence of endospore attachment on the nematode cuticle. Conclusions: Here we provide evidence of an early transcriptional response by the nematode upon infection by Pasteuria prior to root invasion. We found that adhesion of Pasteuria endospores to the cuticle induced a down-regulated protein response in the nematode. In addition, we show that fructose bisphosphate aldolase, glucosyl transferase, aspartic protease and ubiquitin coding transcripts are involved in modulating the endospore attachment on the nematode cuticle. Our results add new and significant information to the existing knowledge on early molecular interaction between M. incognita and P. penetrans.Peer reviewedFinal Published versio

Inverse magnetic catalysis in dense holographic matter

We study the chiral phase transition in a magnetic field at finite temperature and chemical potential within the Sakai-Sugimoto model, a holographic top-down approach to (large-N_c) QCD. We consider the limit of a small separation of the flavor D8-branes, which corresponds to a dual field theory comparable to a Nambu-Jona Lasinio (NJL) model. Mapping out the surface of the chiral phase transition in the parameter space of magnetic field strength, quark chemical potential, and temperature, we find that for small temperatures the addition of a magnetic field decreases the critical chemical potential for chiral symmetry restoration - in contrast to the case of vanishing chemical potential where, in accordance with the familiar phenomenon of magnetic catalysis, the magnetic field favors the chirally broken phase. This "inverse magnetic catalysis" (IMC) appears to be associated with a previously found magnetic phase transition within the chirally symmetric phase that shows an intriguing similarity to a transition into the lowest Landau level. We estimate IMC to persist up to 10^{19} G at low temperatures.Comment: 42 pages, 11 figures, v3: extended discussion; new appendix D; references added; version to appear in JHE

Chiral Symmetry Breaking and External Fields in the Kuperstein-Sonnenschein Model

A novel holographic model of chiral symmetry breaking has been proposed by Kuperstein and Sonnenschein by embedding non-supersymmetric probe D7 and anti-D7 branes in the Klebanov-Witten background. We study the dynamics of the probe flavours in this model in the presence of finite temperature and a constant electromagnetic field. In keeping with the weakly coupled field theory intuition, we find the magnetic field promotes spontaneous breaking of chiral symmetry whereas the electric field restores it. The former effect is universally known as the "magnetic catalysis" in chiral symmetry breaking. In the presence of an electric field such a condensation is inhibited and a current flows. Thus we are faced with a steady-state situation rather than a system in equilibrium. We conjecture a definition of thermodynamic free energy for this steady-state phase and using this proposal we study the detailed phase structure when both electric and magnetic fields are present in two representative configurations: mutually perpendicular and parallel.Comment: 50 pages, multiple figures, minor typo fixed, references adde

Predicting live birth, preterm and low birth weight infant after in-vitro fertilisation: a prospective study of 144018 treatment cycles

Background The extent to which baseline couple characteristics affect the probability of live birth and adverse perinatal outcomes after assisted conception is unknown. Methods and Findings We utilised the Human Fertilisation and Embryology Authority database to examine the predictors of live birth in all in vitro fertilisation (IVF) cycles undertaken in the UK between 2003 and 2007 (n = 144,018). We examined the potential clinical utility of a validated model that pre-dated the introduction of intracytoplasmic sperm injection (ICSI) as compared to a novel model. For those treatment cycles that resulted in a live singleton birth (n = 24,226), we determined the associates of potential risk factors with preterm birth, low birth weight, and macrosomia. The overall rate of at least one live birth was 23.4 per 100 cycles (95% confidence interval [CI] 23.2–23.7). In multivariable models the odds of at least one live birth decreased with increasing maternal age, increasing duration of infertility, a greater number of previously unsuccessful IVF treatments, use of own oocytes, necessity for a second or third treatment cycle, or if it was not unexplained infertility. The association of own versus donor oocyte with reduced odds of live birth strengthened with increasing age of the mother. A previous IVF live birth increased the odds of future success (OR 1.58, 95% CI 1.46–1.71) more than that of a previous spontaneous live birth (OR 1.19, 95% CI 0.99–1.24); p-value for difference in estimate <0.001. Use of ICSI increased the odds of live birth, and male causes of infertility were associated with reduced odds of live birth only in couples who had not received ICSI. Prediction of live birth was feasible with moderate discrimination and excellent calibration; calibration was markedly improved in the novel compared to the established model. Preterm birth and low birth weight were increased if oocyte donation was required and ICSI was not used. Risk of macrosomia increased with advancing maternal age and a history of previous live births. Infertility due to cervical problems was associated with increased odds of all three outcomes—preterm birth, low birth weight, and macrosomia. Conclusions Pending external validation, our results show that couple- and treatment-specific factors can be used to provide infertile couples with an accurate assessment of whether they have low or high risk of a successful outcome following IVF