Hybrid natural inflation from non Abelian discrete symmetry

A spontaneously broken global discrete symmetry may have pseudo Goldstone modes associated with the spontaneous breaking of the approximate continuous symmetry of the low dimension terms in the Lagrangian. These provide natural candidates for an inflaton that can generate slow roll inflation. We show that, in the case of a non Abelian discrete symmetry, the pseudo Goldstone modes readily couple to further scalar fields in a manner that the end of inflation is determined by these additional scalar fields, generating hybrid inflation. We give a simple parameterisation of the inflationary potential in this case, determine the inflationary parameters resulting, and show that phenomenological successful inflation is possible while keeping the scale of symmetry breaking sub-Plankian. Unlike natural inflation the inflation scale can be very low. We construct two simple hybrid inflation models, one non supersymmetric and one supersymmetric. In the latter case no parameters need be chosen anomalously small.Comment: Accepted for publication in Phys. Lett.

Perfectionism and changes in athlete burnout over three months: Interactive effects of personal standards and evaluative concerns perfectionism

Objectives: A recent longitudinal study with junior athletes (Madigan, Stoeber, & Passfield, 2015) found perfectionism to predict changes in athlete burnout: evaluative concerns perfectionism predicted increases in burnout over a 3-month period, whereas personal standards perfectionism predicted decreases. The present study sought to expand on these findings by using the framework of the 2 × 2 model of perfectionism (Gaudreau & Thompson, 2010) to examine whether evaluative concerns perfectionism and personal standards perfectionism show interactions in predicting changes in athlete burnout. Design: Two-wave longitudinal design. Method: The present study examined self-reported evaluative concerns perfectionism, personal standards perfectionism, and athlete burnout in 111 athletes (mean age 24.8 years) over 3 months of active training. Results and Conclusion: When moderated regression analyses were employed, interactive effects of evaluative concerns perfectionism × personal standards perfectionism were found indicating that personal standards perfectionism buffered the effects of evaluative concerns perfectionism on total burnout and physical/emotional exhaustion. To interpret these effects, the 2 × 2 model of perfectionism provides a useful theoretical framework

Hybrid Natural Low Scale Inflation

We discuss the phenomenological implications of hybrid natural inflation models in which the inflaton is a pseudo-Goldstone boson but inflation is terminated by a second scalar field. A feature of the scheme is that the scale of breaking of the Goldstone symmetry can be lower than the Planck scale and so gravitational corrections are under control. We show that, for supersymmetric models, the scale of inflation can be chosen anywhere between the Lyth upper bound and a value close to the electroweak breaking scale. Unlike previous models of low scale inflation the observed density perturbations and spectral index are readily obtained by the choice of the free parameters

The global mass - to - light ratio of SLACS lenses

The dark matter content of early,- type galaxies (ETGs) is a hotly debated topic with contrasting results arguing in favour or against the presence of significant dark mass within the effective radius and the change with luminosity and mass. In order to address this question, we investigate here the global mass - to - light ratio $\Upsilon(r) = M(r)/L(r)$ of a sample of 21 lenses observed within the Sloan Lens ACS (SLACS) survey. We follow the usual approach of modeling the galaxy as a two component systems, but we use a phenomenological ansatz for $\Upsilon(r)$, proposed by some of us in Tortora et al. (2007), able to smoothly interpolate between constant $M/L$ models and a wide class of dark matter haloes. The resulting galaxy model is then fitted to the data on the Einstein radius and velocity dispersion. Our phenomenological model turns out to be in well agreement with the data suggesting the presence of massive dark matter haloes in order to explain the lensing and dynamics properties of the SLACS lenses. According to the values of the dark matter mass fraction, we argue that the halo may play a significant role in the inner regions probed by the data, but such a conclusion strongly depends on the adopted initial mass function of the stellar population. Finally, we find that the dark matter mass fraction within $R_{eff}$ scales with both the total luminosity and stellar mass in such a way that more luminous (and hence more massive) galaxies have a larger dark matter content.Comment: 22 pages, 3 figures, 5 tables, revised version (typos corrected) accepted for publication on Astronomy and Astrophysic

The Galactic Halo in Mixed Dark Matter Cosmologies

A possible solution to the small scale problems of the cold dark matter (CDM) scenario is that the dark matter consists of two components, a cold and a warm one. We perform a set of high resolution simulations of the Milky Way halo varying the mass of the WDM particle ($m_{\rm WDM}$) and the cosmic dark matter mass fraction in the WDM component ($\bar{f}_{\rm W}$). The scaling ansatz introduced in combined analysis of LHC and astroparticle searches postulates that the relative contribution of each dark matter component is the same locally as on average in the Universe (e.g. $f_{\rm W,\odot} = \bar{f}_{\rm W}$). Here we find however, that the normalised local WDM fraction ($f_{\rm W,\odot}$ / $\bar{f}_{\rm W}$) depends strongly on $m_{\rm WDM}$ for $m_{\rm WDM} <$ 1 keV. Using the scaling ansatz can therefore introduce significant errors into the interpretation of dark matter searches. To correct this issue a simple formula that fits the local dark matter densities of each component is provided.Comment: 19 pages, 10 figures, accepted for publication in JCA

The Huntington's disease mutation impairs Huntingtin's role in the transport of NF-κB from the synapse to the nucleus

Expansion of a polyglutamine (polyQ) tract in the Huntingtin (Htt) protein causes Huntington's disease (HD), a fatal inherited neurodegenerative disorder. Loss of the normal function of Htt is thought to be an important pathogenetic component of HD. However, the function of wild-type Htt is not well defined. Htt is thought to be a multifunctional protein that plays distinct roles in several biological processes, including synaptic transmission, intracellular transport and neuronal transcription. Here, we show with biochemical and live cell imaging studies that wild-type Htt stimulates the transport of nuclear factor κ light-chain-enhancer of activated B cells (NF-κB) out of dendritic spines (where NF-κB is activated by excitatory synaptic input) and supports a high level of active NF-κB in neuronal nuclei (where NF-κB stimulates the transcription of target genes). We show that this novel function of Htt is impaired by the polyQ expansion and thus may contribute to the etiology of HD

Perfectionism and achievement goals revisited: The 3 × 2 achievement goal framework

Objectives: Perfectionistic strivings (PS) and perfectionistic concerns (PC) have shown different profiles with the 2 × 2 achievement goals in sport. Whether PS and PC also show comparable profiles with the achievement goals of the expanded 3 × 2 framework, however, is unclear. Design: Cross-sectional. Method: We examined self-reported perfectionistic strivings, perfectionistic concerns, and the 3 × 2 achievement goals in 136 junior athletes (mean age 17.0 years). Results: The results of structural equation modeling showed that PS were positively associated with task-, self-, and other-approach goals and negatively with task- and self-avoidance goals. In contrast, PC were positively associated with task-, self-, and other-avoidance goals and negatively with task- and self-approach goals. Conclusions: The findings suggest that PS and PC show different profiles also with the 3 × 2 achievement goals which may help explain why the two perfectionism dimensions show differential relations with achievement-related outcomes in sport

The relationship between perfectionism and psychopathology: a meta-analysis

Objective: The clinical significance of 2 main dimensions of perfectionism (perfectionistic strivings and perfectionistic concerns) was examined via a meta-analysis of studies investigating perfectionism in the psychopathology literature. Method: We investigated relationships between psychopathology outcomes (clinical diagnoses of depression, anxiety disorders, obsessive-compulsive disorder, and eating disorders; symptoms of these disorders; and outcomes related to psychopathology, such as deliberate self-harm, suicidal ideation, and general distress) and each perfectionism dimension. The relationships were examined by evaluating (a) differences in the magnitude of association of the 2 perfectionism dimensions with psychopathology outcomes and (b) subscales of 2 common measures of perfectionism. Results: A systematic literature search retrieved 284 relevant studies, resulting in 2,047 effect sizes that were analysed with meta-analysis and meta-regression while accounting for data dependencies. Conclusion: Findings support the notion of perfectionism as a transdiagnostic factor by demonstrating that both dimensions are associated with various forms of psychopathology

Galaxy Formation in Heavily Overdense Regions at z~10: the Prevalence of Disks in Massive Halos

Using a high-resolution cosmological numerical simulation, we have analyzed the evolution of galaxies at z~10 in a highly overdense region of the universe. These objects could represent the high redshift galaxies recently observed by the Hubble's WFC3, and be as well possible precursors of QSOs at z~6-7. To overcome the sampling and resolution problems in cosmological simulations, we have used the Constrained Realizations method. Our main result for z~10 shows the region of 3.5h^{-1}Mpc radius in comoving coordinates completely dominated by disk galaxies in the total mass range of >=10^9h^{-1}Mo. We have verified that the gaseous and stellar disks we identify are robust morphological features, capable of surviving the ongoing merger process at these redshifts. Below this mass range, we find a sharp decline in the disk fraction to negligible numbers. At this redshift, the disks appear to be gas-rich and the dark matter halos baryon-rich, by a factor of ~2-3 above the average fraction of baryons in the universe. The prevalence of disk galaxies in the high density peaks during the epoch of reionization is contrary to the morphology-density trend observed at low redshifts.Comment: To be published by the Astrophysical Journal Letters, 5 pages, 3 figures. Small corrections following the referee repor

Interventions for promoting smoking cessation during pregnancy.

BACKGROUND: Smoking remains one of the few potentially preventable factors associated with low birthweight, preterm birth and perinatal death. OBJECTIVES: To assess the effects of smoking cessation programs implemented during pregnancy on the health of the fetus, infant, mother, and family. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Tobacco Addiction Group trials register (July 2003), MEDLINE (January 2002 to July 2003), EMBASE (January 2002 to July 2003), PsychLIT (January 2002 to July 2003), CINAHL (January 2002 to July 2003), and AUSTHEALTH (January 2002 to 2003). We contacted trial authors to locate additional unpublished data. We handsearched references of identified trials and recent obstetric journals. SELECTION CRITERIA: Randomised and quasi-randomised trials of smoking cessation programs implemented during pregnancy. DATA COLLECTION AND ANALYSIS: Four reviewers assessed trial quality and extracted data independently. MAIN RESULTS: This review included 64 trials. Fifty-one randomised controlled trials (20,931 women) and six cluster-randomised trials (over 7500 women) provided data on smoking cessation and/or perinatal outcomes. Despite substantial variation in the intensity of the intervention and the extent of reminders and reinforcement through pregnancy, there was an increase in the median intensity of both 'usual care' and interventions over time. There was a significant reduction in smoking in the intervention groups of the 48 trials included: (relative risk (RR) 0.94, 95% confidence interval (CI) 0.93 to 0.95), an absolute difference of six in 100 women continuing to smoke. The 36 trials with validated smoking cessation had a similar reduction (RR 0.94, 95% CI 0.92 to 0.95). Smoking cessation interventions reduced low birthweight (RR 0.81, 95% CI 0.70 to 0.94) and preterm birth (RR 0.84, 95% CI 0.72 to 0.98), and there was a 33 g (95% CI 11 g to 55 g) increase in mean birthweight. There were no statistically significant differences in very low birthweight, stillbirths, perinatal or neonatal mortality but these analyses had very limited power. One intervention strategy, rewards plus social support (two trials), resulted in a significantly greater smoking reduction than other strategies (RR 0.77, 95% CI 0.72 to 0.82). Five trials of smoking relapse prevention (over 800 women) showed no statistically significant reduction in relapse. REVIEWERS' CONCLUSIONS: Smoking cessation programs in pregnancy reduce the proportion of women who continue to smoke, and reduce low birthweight and preterm birth. The pooled trials have inadequate power to detect reductions in perinatal mortality or very low birthweight