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Alcohol abuse and dependence are frequently associated with psychiatric disorders and Personality Disorders, with differences among genders. However, only few studies investigated gender differences in personality disorders among alcoholics.
The aim of our study is to investigate personality disorders in a sample of inpatient alcoholics applying Millon Clinical Multiaxial Inventory - III, and to describe gender differences in prevalence and comorbidity of personality disorders.
The study population consist of 206 alcohol dependent patients entering detoxification treatment in a specialized clinic in Italy. At enrollment, patients filled in the Millon Clinical Multiaxial Inventory - III for the assessment of personality disorders and the AUDIT Test for the evaluation of alcohol consumption.
The sample consisted of 150 men and 56 women. According to Millon assessment, 25% percent of men vs 12% of women had one PDs, 16% vs 23% had two PDs, and 46% vs 48% had more than three PDs. A statistically significant higher proportion of women got high scores on Avoidant (21.4% vs 9.3%, p = 0.020), Self-Defeating (50.0% vs 24.0%, p < 0.001), and Borderline scale (42.9% vs 25.3%, p = 0.015). Associations among PD are sporadic among men whilst are very frequent among women. Depressive, Self-Defeating and Borderline PDs are frequently associated both to other PDs and among each other, suggesting a possible female pattern.
Borderline PD is confirmed to be more frequent among alcoholic women than among men. More studies are needed to clarify prevalence and associations of PDs, prognosis, and gender differences in alcoholics patients.
For the shortest period exoplanets, star-planet tidal interactions are likely to have played a major role in the ultimate orbital evolution of the planets and on the spin evolution of the host stars. Although low-mass stars are magnetically active objects, the question of how the star’s magnetic field impacts the excitation, propagation and dissipation of tidal waves remains open. We have derived the magnetic contribution to the tidal interaction and estimated its amplitude throughout the structural and rotational evolution of low-mass stars (from K to F-type). We find that the star’s magnetic field has little influence on the excitation of tidal waves in nearly circular and coplanar Hot-Jupiter systems, but that it has a major impact on the way waves are dissipated.
In this chapter we briefly summarize how angular momentum is being transported and exchanged between convective and radiative zones in stars. We discuss what physical processes influence the internal rotation history of stars on short to long (secular) time scales.
The astrophysical context
Stars are rotating magnetic bodies with complex internal and external dynamics. Observations using helioseismology (e.g., García et al., 2007), asteroseismology (e.g., Deheuvels et al., 2014), and spectropolarimetry (e.g., Donati and Land street, 2009) techniques put more and more constraints on this intricate dynamics. To get a complete and coherent picture of dynamical processes in stars and of the associated transport of angular momentum that goes beyond the “standard” modeling of stellar structure and evolution (Maeder, 2009) one needs to develop new models by introducing an improved physical description of these time-dependent processes. However, to simulate such processes in a star in full detail requires treating spatial and temporal scales spanning about 10 orders of magnitude. This is clearly not yet feasible, even with the most powerful computers available today. Therefore, one can choose to describe what occurs on a dynamical time scale (such as a convective turnover time or stellar magnetic cycles) or on the long-term evolution where the typical characteristic time scale is the dominant nuclear reactions. The same applies for spatial scales. One has to choose which relevant scale one needs to model in order to accurately describe the spatial dependence of the physical processes (convection motions, MHD instabilities, transport and mixing processes, surface dynamics).This is the reason why it is nowadays necessary to use and couple 1D, 2D, and 3D models to get a global picture of macroscopic MHD transport processes in stars over short to secular time scales.
In this chapter, we report on the state of the art of the modeling of the transport of angular momentum in stars both in convection and in radiation zones and we present our main contributions to this field of research.
Observations of stable mainly dipolar magnetic fields at the surface of ~7% of single hot stars indicate that these fields are of fossil origin, i.e. they descend from the seed field in the molecular clouds from which the stars were formed. The recent results confirm this theory. First, theoretical work and numerical simulations confirm that the properties of the observed fields correspond to those expected from fossil fields. They also showed that rapid rotation does not modify the surface dipolar magnetic configurations, but hinders the stability of fossil fields. This explains the lack of correlation between the magnetic field properties and stellar properties in massive stars. It may also explain the lack of detections of magnetic fields in Be stars, which rotate close to their break-up velocity. In addition, observations by the BinaMIcS collaboration of hot stars in binary systems show that the fraction of those hosting detectable magnetic fields is much smaller than for single hot stars. This could be related to results obtained in simulations of massive star formation, which show that the stronger the magnetic field in the original molecular cloud, the more difficult it is to fragment massive cores to form several stars. Therefore, more and more arguments support the fossil field theory.
The B fields in OB stars (BOB) survey is an ESO large programme collecting spectropolarimetric observations for a large number of early-type stars in order to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. As of July 2014, a total of 98 objects were observed over 20 nights with FORS2 and HARPSpol. Our preliminary results indicate that the fraction of magnetic OB stars with an organised, detectable field is low. This conclusion, now independently reached by two different surveys, has profound implications for any theoretical model attempting to explain the field formation in these objects. We discuss in this contribution some important issues addressed by our observations (e.g., the lower bound of the field strength) and the discovery of some remarkable objects.
Stochastic gravity waves have been recently detected and characterised in stars thanks to space asteroseismology and they may play an important role in the evolution of stellar angular momentum. In this context, the observational study of the CoRoT hot Be star HD 51452 suggests a potentially strong impact of rotation on stochastic excitation of gravito-inertial waves in rapidly rotating stars. In this work, we present our results on the action of the Coriolis acceleration on stochastic wave excitation by turbulent convection. We study the change of efficiency of this mechanism as a function of the waves' Rossby number and we demonstrate that the excitation presents two different regimes for super-inertial and sub-inertial frequencies. Consequences for rapidly rotating early-type stars and the transport of angular momentum in their interiors are discussed.
It is now well established that a fraction of the massive (M > 8 M⊙) star population hosts strong, organised magnetic fields, most likely of fossil origin. The details of the generation and evolution of these fields are still poorly understood. The BinaMIcS project takes an important step towards the understanding of the interplay between binarity and magnetism during the stellar formation and evolution, and in particular the genesis of fossil fields, by studying the magnetic properties of close binary systems. The components of such systems are most likely formed together, at the same time and in the same environment, and can therefore help us to disentangle the role of initial conditions on the magnetic properties of the massive stars from other competing effects such as age or rotation. We present here the main scientific objectives of the BinaMIcS project, as well as preliminary results from the first year of observations from the associated ESPaDOnS and Narval spectropolarimetric surveys.
The MiMeS project demonstrated that a small fraction of massive stars (around 7%) presents large-scale, stable, generally dipolar magnetic fields at their surface. These fields that do not present any evident correlations with stellar mass or rotation are supposed to be fossil remnants of the initial phases of stellar evolution. They result from the relaxation to MHD equilibrium states, during the formation of stable radiation zones, of initial fields resulting from a previous convective phase. In this work, we present new theoretical results, where we generalize previous studies by taking rotation into account. The properties of relaxed fossil fields are compared to those obtained when rotation is ignored. Consequences for magnetic fields in the radiative envelope of rotating early-type stars and their stability are finally discussed.
In this article, we show how asteroseismology and spectropolarimetry allow to probe dynamical processes in massive star interiors. First, we give a summary of the state-of-the-art. Second, we recall the MHD mechanisms that take place in massive stars. Next, we show how asteroseismology gives strong constraints on the internal mixing and transport of angular momentum while spectropolarimetry allows to unravel the role played by magnetic fields.
Tidal dissipation in stars is one of the key physical mechanisms that drive the evolution of binary and multiple stars. As in the Earth oceans, it corresponds to the resonant excitation of their eigenmodes of oscillation and their damping. Therefore, it strongly depends on the internal structure, rotation, and dissipative mechanisms in each component. In this work, we present a local analytical modeling of tidal gravito-inertial waves excited in stellar convective and radiative regions respectively. This model allows us to understand in details the properties of the resonant tidal dissipation as a function of the excitation frequencies, the rotation, the stratification, and the viscous and thermal properties of the studied fluid regions. Then, the frequencies, height, width at half-height, and number of resonances as well as the non-resonant equilibrium tide are derived analytically in asymptotic regimes that are relevant in stellar interiors. Finally, we demonstrate how viscous dissipation of tidal waves leads to a strongly erratic orbital evolution in the case of a coplanar binary system. We characterize such a non-regular dynamics as a function of the height and width of resonances, which have been previously characterized thanks to our local fluid model.
The Magnetism in Massive Stars (MiMeS) project represents the largest systematic survey of stellar magnetism ever undertaken. Based on a sample of over 550 Galactic B and O-type stars, the MiMeS project has derived the basic characteristics of magnetism in hot, massive stars. Herein we report preliminary results.
Internal gravity waves are excited in stellar interiors thanks to turbulent convective regions, to opacity bumps and to tides when there is a close stellar or planetary companion. Then, they propagate in stably stratified stellar radiation zones where they deposit/extract angular momentum by damping processes and corotation resonances. This modifies the rotational evolution as well as the internal mixing in stars. In this review, we will present the state of the art for modelling such transport mechanisms with a peculiar focus on the most recent advances taking into account the influence of rotation, shear, and magnetic fields on internal gravity waves. Next, we will discuss consequences for stars dynamical evolution and what can be learnt from stellar seismology.
Angular momentum is one of the most fundamental properties of matter in our universe, which has deep consequences on its evolution. In particular, the formation and the physical characteristics of cosmic structures such as galaxies, stars and planets are intimately linked to the amount of angular momentum they carry, to the way it is redistributed within the system and exchanged with the surrounding environment. Considerable efforts have been undertaken during the last decades to identify and quantify the various physical mechanisms responsible for the transport of angular momentum in these objects. While some of them are relatively well understood, in many circumstances the underlying mechanism turns out to be extremely complex and very challenging. In this introductory chapter, we first introduce some general considerations on the angular momentum impact and transport. We then derive the MHD equations both in the ideal and non-ideal limit. Finally, after deriving the conservative form of the angular momentum equation, we discuss in more details some of the mechanisms that can contribute to the transport of angular momentum in various astrophysical contexts.
Internal waves and tidal interactions constitute powerful mechanisms for angular momentum exchanges in star-planet systems. In this lecture, we review the state of the art of their modelling and we discuss their impact on the evolution of stellar systems. In this context, we first show how internal waves are able to deeply modify the secular transport of angular momentum in stellar interiors in the whole Hertzsprung-Russelll diagram. Then, we show how tidal waves, as well as the related exchanges of angular momentum, strongly depend on the internal structure of stars and planets.
Monitoring injecting drug users' (IDUs) health is challenging because IDUs form a difficult to reach population. We examined the impact of recruitment setting on hepatitis C prevalence. Individual datasets from 12 studies were merged. Predictors of HCV positivity were sought through a multilevel analysis using a mixed-effects logistic model, with study identifier as random intercept. HCV prevalence ranged from 21% to 86% across the studies. Overall, HCV prevalence was higher in IDUs recruited in drug treatment centres compared to those recruited in low-threshold settings (74% and 42%, respectively, P < 0·001). Recruitment setting remained significantly associated with HCV prevalence after adjustment for duration of injecting and recent injection (adjusted odds ratio 0·7, 95% confidence interval 0·6–0·8, P = 0·05). Recruitment setting may have an impact on HCV prevalence estimates of IDUs in Europe. Assessing the impact of mixed recruitment strategies, including respondent-driven sampling, on HCV prevalence estimates, would be valuable.
The Magnetism in Massive Stars (MiMeS) Project is a consensus collaboration among many of the foremost international researchers of the physics of hot, massive stars, with the basic aim of understanding the origin, evolution and impact of magnetic fields in these objects. At the time of writing, MiMeS Large Programs have acquired over 950 high-resolution polarised spectra of about 150 individual stars with spectral types from B5-O4, discovering new magnetic fields in a dozen hot, massive stars. The quality of this spectral and magnetic matériel is very high, and the Collaboration is keen to connect with colleagues capable of exploiting the data in new or unforeseen ways. In this paper we review the structure of the MiMeS observing programs and report the status of observations, data modeling and development of related theory.
We review the interaction in intermediate and high mass stars between their evolution and magnetic and chemical properties. We describe the theory of Ap-star ‘fossil’ fields, before touching on the expected secular diffusive processes which give rise to evolution of the field. We then present recent results from a spectropolarimetric survey of Herbig Ae/Be stars, showing that magnetic fields of the kind seen on the main-sequence already exist during the pre-main sequence phase, in agreement with fossil field theory, and that the origin of the slow rotation of Ap/Bp stars also lies early in the pre-main sequence evolution; we also present results confirming a lack of stars with fields below a few hundred gauss. We then seek which macroscopic motions compete with atomic diffusion in determining the surface abundances of AmFm stars. While turbulent transport and mass loss, in competition with atomic diffusion, are both able to explain observed surface abundances, the interior abundance distribution is different enough to potentially lead to a test using asterosismology. Finally we review progress on the turbulence-driving and mixing processes in stellar radiative zones.
Magnetic field and their related dynamical effects are thought to be important in stellar radiation zones. For instance, it has been suggested that a dynamo, sustained by a m = 1 MHD instability of toroidal magnetic fields (discovered by Tayler in 1973), could lead to a strong transport of angular momentum and of chemicals in such stable regions. We wish here to recall the different magnetic transport processes present in radiative zone and show how the dynamo can operate by recalling the conditions required to close the dynamo loop (BPol → BTor → BPol). Helped by high-resolution 3D MHD simulations using the ASH code in the solar case, we confirm the existence of the m = 1 instability, study its non-linear saturation, but we do not detect, up to a magnetic Reylnods number of 105, any dynamo action.
We study the impact on the stellar structure of a large-scale magnetic field in stellar radiation zones. The field is in magneto-hydrostatic (MHS) equilibrium and has a non force-free character, which allows us to study its influence both on the mechanical and and on the energetic balances. This approach is illustrated in the case of an Ap star where the magnetic field matches at the surface with an external potential one. Perturbations of the stellar structure are semi-analytically computed. The relative importance of the magnetic physical quantities is discussed and a hierarchy, aiming at distinguishing various refinement degrees in the implementation of a large-scale magnetic field in a stellar evolution code, is established. This treatment also allows us to deduce the gravitational multipolar moments and the change in effective temperature associated with the presence of a magnetic field.