Genetics of decayed sexual traits in a parasitoid wasp with endosymbiont-induced asexuality.

Trait decay may occur when selective pressures shift, owing to changes in environment or life style, rendering formerly adaptive traits non-functional or even maladaptive. It remains largely unknown if such decay would stem from multiple mutations with small effects or rather involve few loci with major phenotypic effects. Here, we investigate the decay of female sexual traits, and the genetic causes thereof, in a transition from haplodiploid sexual reproduction to endosymbiont-induced asexual reproduction in the parasitoid wasp Asobara japonica. We take advantage of the fact that asexual females cured of their endosymbionts produce sons instead of daughters, and that these sons can be crossed with sexual females. By combining behavioral experiments with crosses designed to introgress alleles from the asexual into the sexual genome, we found that sexual attractiveness, mating, egg fertilization and plastic adjustment of offspring sex ratio (in response to variation in local mate competition) are decayed in asexual A. japonica females. Furthermore, introgression experiments revealed that the propensity for cured asexual females to produce only sons (because of decayed sexual attractiveness, mating behavior and/or egg fertilization) is likely caused by recessive genetic effects at a single locus. Recessive effects were also found to cause decay of plastic sex-ratio adjustment under variable levels of local mate competition. Our results suggest that few recessive mutations drive decay of female sexual traits, at least in asexual species deriving from haplodiploid sexual ancestors.

Currency Forecast Errors at Times of Low Interest Rates: Evidence from Survey Data on the Yen/Dollar Exchange Rate

Using survey expectations data and Markov-switching models, this paper evaluates the characteristics and evolution of investors' forecast errors about the yen/dollar exchange rate. Since our model is derived from the uncovered interest rate parity (UIRP) condition and our data cover a period of low interest rates, this study is also related to the forward premium puzzle and the currency carry trade strategy. We obtain the following results. First, with the same forecast horizon, exchange rate forecasts are homogeneous among different industry types, but within the same industry, exchange rate forecasts differ if the forecast time horizon is different. In particular, investors tend to undervalue the future exchange rate for long term forecast horizons; however, in the short run they tend to overvalue the future exchange rate. Second, while forecast errors are found to be partly driven by interest rate spreads, evidence against the UIRP is provided regardless of the forecasting time horizon; the forward premium puzzle becomes more significant in shorter term forecasting errors. Consistent with this finding, our coefficients on interest rate spreads provide indirect evidence of the yen carry trade over only a short term forecast horizon. Furthermore, the carry trade seems to be active when there is a clear indication that the interest rate will be low in the future.

Social norms, morals and self-interest as determinants of pro-environment behaviour.

This paper considers the role which selfish, moral and social incentives and pressures play in explaining the extent to which stated choices over pro-environment behaviours vary across individuals. The empirical context is choices over household waste contracts and recycling actions in Poland. A theoretical model is used to show how cost-based motives and the desire for a positive self- and social image combine to determine the utility from alternative choices of recycling behaviour. We then describe a discrete choice experiment designed to empirically investigate the effects such drivers have on stated choices. Using a latent class model, we distinguish three types of individual who are described as duty-orientated recyclers, budget recyclers and homo oeconomicus. These groups vary in their preferences for how frequently waste is collected, and the number of categories into which household waste must be recycled. Our results have implications for the design of future policies aimed at improving participation in recycling schemes.

Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution.

Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻&supl;³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.

Sexual distinction between 5th instar nymphs of six species of Triatominae (Hemiptera, Reduviidae)

The aim of this paper is to present the analysis of sexual morphological differences observed in 5th instar nymphs of the following species: Panstrongylus megistus; Rhodnius neglectus; Triatoma brasiliensis; T. infestans; T. matogrosensis and T. tibiamaculata. Male and female nymphs were examined and photographed with a Scanning Electron Microscope. The 9th segment dimensions of dorsal and ventral faces were determined through a Profile Projector. Results and statistical analysis showed significant differences: the 9th sternite is significantly broader in male than female nymphs, while in five species; tergites in female nymphs are broad and in male are narrow.

The neuropeptide Y Y1 receptor regulates leptin-mediated control of energy homeostasis and reproductive functions.

The orexigenic neurotransmitter neuropeptide Y (NPY) plays a central role in the hypothalamic control of food intake and energy balance. NPY also exerts an inhibition of the gonadotrope axis that could be important in the response to poor metabolic conditions. In contrast, leptin provides an anorexigenic signal to centrally control the body needs in energy. Moreover, leptin contributes to preserve adequate reproductive functions by stimulating the activity of the gonadotrope axis. It is of interest that hypothalamic NPY represents a primary target of leptin actions. To evaluate the importance of the NPY Y1 and Y5 receptors in the downstream pathways modulated by leptin and controlling energy metabolism as well as the activity of the gonadotrope axis, we studied the effects of leptin administration on food intake and reproductive functions in mice deficient for the expression of either the Y1 or the Y5 receptor. Furthermore, the role of the Y1 receptor in leptin resistance was determined in leptin-deficient ob/ob mice bearing a null mutation in the NPY Y1 locus. Results point to a crucial role for the NPY Y1 receptor in mediating the NPY pathways situated downstream of leptin actions and controlling food intake, the onset of puberty, and the maintenance of reproductive functions.

Inconsistency between different measures of sexual selection.

Measuring the intensity of sexual selection is of fundamental importance to the study of sexual dimorphism, population dynamics, and speciation. Several indices, pools of individuals, and fitness proxies are used in the literature, yet their relative performances are strongly debated. Using 12 independent common lizard populations, we manipulated the adult sex ratio, a potentially important determinant of the intensity of sexual selection at a particular time and place. We investigated differences in the intensity of sexual selection, as estimated using three standard indices of sexual selection-the standardized selection gradient (β'), the opportunity of selection (I), and the Bateman gradient (βss)--calculated for different pools of individuals and different fitness proxies. We show that results based on estimates of I were the opposite of those derived from the other indices, whereas results based on estimates of β' were consistent with predictions derived from knowledge about the species' mating system. In addition, our estimates of the strength and direction of sexual selection depended on both the fitness proxy used and the pool of individuals included in the analysis. These observations demonstrate inconsistencies in distinct measures of sexual selection and underscore the need for caution when comparing studies and species.

Sexual behaviour and stridulation during mating in Triatoma infestans (Hemiptera: Reduviidae)

Factors affecting mating behaviour in the bug Triatoma infestans were quantitatively studied in the laboratory. Experimental conditions were established so that the probability of copulation increased with the time elapsed since the first adult meal. Copulatory attempts by males did not vary as a function of time, but rejections by females became significantly less frequent with the post feeding time. Non-receptive females displayed four types of rejection behaviour, i.e. flattening, stridulation, evasion and abdominal movements. The occurrence of stridulation performed by females in a sexual context was observed in a regular fashion and was quantified for the first time in this species.

Pretreatment and outcome correlates of past sexual and physical trauma in 118 bipolar I disorder patients with a first episode of psychotic mania.

OBJECTIVES: To assess the prevalence and correlates of childhood and adolescent sexual and/or physical abuse (SPA) in bipolar I disorder (BDI) patients treated for a first episode of psychotic mania. METHODS: The Early Psychosis Prevention and Intervention Centre admitted 786 first-episode psychosis patients between 1998 and 2000. Data were collected from patients' files using a standardized questionnaire. A total of 704 files were available; 43 were excluded because of a nonpsychotic diagnosis at endpoint and 3 due to missing data regarding past stressful events. Among 658 patients with available data, 118 received a final diagnosis of BDI and were entered in this study. RESULTS: A total of 80% of patients had been exposed to stressful life events during childhood and adolescence and 24.9% to SPA; in particular, 29.8% of female patients had been exposed to sexual abuse. Patients who were exposed to SPA had poorer premorbid functioning, higher rates of forensic history, were less likely to live with family during treatment period, and were more likely to disengage from treatment. CONCLUSIONS: SPA is highly prevalent in BDI patients presenting with a first episode of psychotic mania; exposed patients have lower premorbid functional levels and poorer engagement with treatment. The context in which such traumas occur must be explored in order to determine whether early intervention strategies may contribute to diminish their prevalence. Specific psychological interventions must also be developed.

Característiques psicosocials i judicials dels menors implicats en denúncies d’abús sexual: ent casos valorats a l’equip d’assessorament tècnic penal de Barcelona

Característiques psicosocials i judicials dels menors víctimes d’abús sexual Els delictes contra la llibertat sexual a la infància són un greu problema social, atesa l’especial vulnerabilitat dels menors i els efectes que el delicte pot suposar en el seu desenvolupament. En el cas dels menors que arriben al sistema judicial, aquesta vulnerabilitat augmenta pel possible efecte de la victimització secundària. Aquesta recerca parteix de la necessitat de conèixer de manera objectiva les característiques dels menors presumptes víctimes d’abús sexual derivats a l’Equip d’Assessorament Tècnic Penal de Barcelona, atès que, si bé hi ha múltiples estudis descriptius amb aquest tipus de població en altres territoris nacionals o en altres països, mai no s’havia realitzat un estudi d’aquestes característiques en el servei de l’EATP. En aquest estudi es van analitzar les dades de 100 menors presumptes víctimes de delictes contra la llibertat sexual, denunciats a la província de Barcelona i derivats al nostre servei per demanda judicial durant un període d’un any. Les principals variables analitzades es van agrupar en les àrees següents: antecedents del delicte (personals i sociofamiliars), variables relacionades amb el delicte (variables judicials, del presumpte agressor i de la intervenció del nostre servei) i conseqüències judicials, personals i sociofamiliars del delicte. Els resultats de l’estudi destaquen que la majoria dels menors són nascuts a Catalunya, tenen més de nou anys i les tres quartes parts són nenes. La meitat de les famílies tenen un perfil tradicional i l’altra meitat són monoparentals o reconstituïdes; es valora un estil educatiu adequat en la majoria dels casos. Es copsa una escassa presència d’antecedents familiars significatius. En els menors predominen els trets de personalitat de submissió, conformisme i introversió, i presenten una escassa psicopatologia prèvia. Predominen els abusos sexuals crònics realitzats per una persona de l’entorn familiar del menor. En general, els testimonis dels menors sobre l’abús resulten globalment creïbles, i és molt baixa la proporció dels testimonis no creïbles. Les principals seqüeles psicològiques copsades en els menors són la simptomatologia ansiosa i posttraumàtica, i hi predominen també els sentiments de rebuig envers l’agressor.

Características psicosociales y judiciales de los menores implicados en denuncias de abuso sexual: cien casos valorados por el equipo de asesoramiento técnico penal de Barcelona

Características psicosociales y judiciales de los menores víctimas de abuso sexual El objetivo es conocer las características psicológicas, sociodemográficas y judiciales de los menores que denuncian delitos contra la libertad sexual en la provincia de Barcelona. La muestra está formada por 100 menores presuntas víctimas de delitos contra la libertad sexual denunciados en la provincia de Barcelona y atendidos por el Equipo de Asesoramiento Penal a la instancia judicial.

Density-dependent pollen limitation and reproductive assurance in a wind-pollinated herb with contrasting sexual systems

1. Wind pollination is thought to have evolved in response to selection for mechanisms to promote pollination success, when animal pollinators become scarce or unreliable. We might thus expect wind-pollinated plants to be less prone to pollen limitation than their insect-pollinated counterparts. Yet, if pollen loads on stigmas of wind-pollinated species decline with distance from pollen donors, seed set might nevertheless be pollen-limited in populations of plants that cannot self-fertilize their progeny, but not in self-compatible hermaphroditic populations.2. Here, we test this hypothesis by comparing pollen limitation between dioecious and hermaphroditic (monoecious) populations of the wind-pollinated herb Mercurialis annua.3. In natural populations, seed set was pollen-limited in low-density patches of dioecious, but not hermaphroditic, M. annua, a finding consistent with patterns of distance-dependent seed set by females in an experimental array. Nevertheless, seed set was incomplete in both dioecious and hermaphroditic populations, even at high local densities. Further, both factors limited the seed set of females and hermaphrodites, after we manipulated pollen and resource availability in a common garden experiment.4. Synthesis. Our results are consistent with the idea that pollen limitation plays a role in the evolution of combined vs. separate sexes in M. annua. Taken together, they point to the potential importance of pollen transfer between flowers on the same plant (geitonogamy) by wind as a mechanism of reproductive assurance and to the dual roles played by pollen and resource availability in limiting seed set. Thus, seed set can be pollen-limited in sparse populations of a wind-pollinated species, where mates are rare or absent, having potentially important demographic and evolutionary implications.

The lack of effect of insulin on luteinizing hormone pulsatility in healthy male volunteers provides evidence of a sexual dimorphism in the metabolic regulation of reproductive hormones.

BACKGROUND: The activity of the neuroendocrine reproductive axis is closely related to nutritional status. This link is particularly important in healthy women, in whom insulin is a positive signal for the reproductive system. In contrast, very little is known regarding this relation in men. OBJECTIVES: This study was designed to evaluate the effect of insulin on the reproductive axis of young male volunteers and to study the effect of short-term hypercaloric feeding on this modulation. DESIGN: The activity of the neuroendocrine reproductive axis was characterized by the pattern of endogenous luteinizing hormone (LH) secretion on the basis of frequent blood sampling protocols. The effect of insulin was tested by comparing the LH secretion pattern between a baseline study and a hyperinsulinemic euglycemic clamp. These studies were performed first in subjects fed a controlled isocaloric diet for 6 d (calculated as 1.5 times their resting metabolic rate) then in the same subjects fed a controlled hypercaloric diet in which 30% extra calories were provided as fat and fructose (3 g · kg(-1) · d(-1)) before undergoing identical protocols. Serum gonadotropins, sex steroids, glucose, insulin, ghrelin, and leptin concentrations were assessed, and the HOMA-IR was calculated. RESULTS: The LH secretion pattern was not affected by insulin or by hypercaloric feeding. Insulin decreased ghrelin and increased leptin concentrations but had no additional effect of hypercaloric feeding despite significantly lower HOMA-IR indexes. CONCLUSIONS: Our data indicate that neither insulin nor short-term hypercaloric feeding has any effect on the activity of the male reproductive axis. They also further support the association between ghrelin and insulin and glucose metabolism. This trial was registered at clinicaltrials.gov as NCT01058681.