Bosonic Preheating in Left-Right-Symmetric SUSY GUTs

We investigate the possibility of a bosonic preheating in the simplest model of supersymmetric Hybridinflation (F-term inflation), which was considered first by Dvali et al. Here the inflationary superpotential is of the O'Raifertaigh-Witten type. The end of inflation is related to a non-thermal phase transition, which in the context of left-right symmetric models lowers the rank of the gauge group. Using the homogeneous classical field ansatz for the appearing condensates, our results indicate that the parametric creation of bosonic particles does not occure in the model under consideration.Comment: 14 pages, 6 figure

A D=4 N=1 Orbifold of Type I Strings

We consider the propagation of Type I open superstrings on orbifolds with four non-compact dimensions and $N=1$ supersymmetry. In this paper, we concentrate on a non-trivial Z_2xZ_2 example. We show that consistency conditions, arising from tadpole cancellation and algebraic sources, require the existence of three sets of Dirichlet 5-branes. We discuss fully the enhancements of the spectrum when these 5-branes intersect. An amusing attribute of these models is the importance of the tree-level (in Type I language) superpotential to the consistent relationship between Higgsing and the motions of 5-branes.Comment: 24 pages, uses LaTeX and epsf.st

Expectations about Fertility and Field of Study among Adolescents: A Case of Self-selection?

In recent studies on the association between education and fertility, increased attention has been paid to the field of study. Women who studied in traditionally more “feminine” fields, like care, teaching, and health, were found to have their children earlier and to have more children than other women. A point of debate in this literature is on the causal direction of this relationship. Does the field of study change the attitudes towards family formation, or do young adults with stronger family-life attitudes self-select into educational fields that emphasize care, teaching, and health? Or do both field of study preferences and family-life attitudes arise before actual choices in these domains are made?We contribute to this debate by examining the relationship between fertility expectations and expected fields of study and occupation among 14-17 year-old adolescents. We use data collected in 2005 from 1500 Dutch adolescents and Structural Equation Modelling (SEM) to examine the associations between expected field of study and occupation and fertility expectations. Our results show that expectations concerning fertility and field of study are already interrelated during secondary education. Both female and male adolescents who expect to pursue studies in fields that focus on care and social interaction (like health care, teaching etc.) are less likely to expect to remain childless. This holds equally for girls and boys. In addition, girls who more strongly aspire to an occupation in which communication skills are important also expect to have more children. We did not find any relationship between expectations of pursuing a communicative field of study and occupation and expectations of earlier parenthood.In addition, among boys, we find that the greater their expectation of opting for an economics, a technical, or a communicative field of study, the less likely they were to expect to remain childless. Boys who expected to study in the economic field also expect to have their first child earlier, but boys expecting to pursue a technical course of studies expect to enter parenthood later. We also found that those who expect to pursue cultural studies are more likely to have a preference for no children, or if they do want children, to have them later in life.Overall, our findings suggest that the processes of elective affinity between the communicative fields of study and work on the one hand and fertility on the other hand are more or less comparable for boys and girls. With respect to the other domains, we find, apart from the gender differences in the relation between fields of study and childlessness, hardly or no gender differences in the expected timing of parenthood and the number of children. The genders do differ in their level of preference for communicative and economics-related fields of study and occupation, but if they do have the same preference, the association with fertility expectations is more or less similar

Effects and side-effects of integrating care: the case of mental health care in the Netherlands

Contains fulltext : 56200.pdf ( ) (Open Access)Purpose: Description and analysis of the effects and side-effects of integrated mental health care in the Netherlands. Context of case: Due to a number of large-scale mergers, Dutch mental health care has become an illustration of integration and coherence of care services. This process of integration, however, has not only brought a better organisation of care but apparently has also resulted in a number of serious side-effects. This has raised the question whether integration is still the best way of reorganising mental health care. Data sources: Literature, data books, patients and professionals, the advice of the Dutch Commission for Mental Health Care, and policy papers. Case description: Despite its organisational and patient-centred integration, the problems in the Dutch mental health care system have not diminished: long waiting lists, insufficient fine tuning of care, public order problems with chronic psychiatric patients, etc. These problems are related to a sharp rise in the number of mental health care registrations in contrast with a decrease of registered patients in first-level services. This indicates that care for people with mental health problems has become solely a task for the mental health care services (monopolisation). At the same time, integrated institutions have developed in the direction of specialised medical care (homogenisation). Monopolisation and homogenisation together have put the integrated institutions into an impossible divided position. Conclusions and discussion: Integration of care within the institutions in the Netherlands has resulted in withdrawal of other care providers. These side-effects lead to a new discussion on the real nature and benefits of an integrated mental health care system. Integration requires also a broadly shared vision on good care for the various target groups. This would require a radicalisation of the distinction between care providers as well as a recognition of the different goals of mental health care.11 p

SO(10)-GUT Coherent Baryogenesis

A model for GUT baryogenesis, coherent baryogenesis within the framework of supersymmetric SO(10), is considered. In particular, we discuss the Barr-Raby model, where at the end of hybrid infl ation charge asymmetries can be created through the time-dependent higgsino-gaugino mixing mass matrix. These asymmetries are processed to Standard Model matter through decays via nonrenormalizable (B-L)-violating operators. We find that a baryon asymmetry in accordance with observation can be generated. An appendix is devoted to provide useful formulas and concrete examples for calculations within SO(10).Comment: 30 pages, 3 figure

Relativistic Turbulence: A Long Way from Preheating to Equilibrium

We study, both numerically and analytically, the development of equilibrium after preheating. We show that the process is characterised by the appearance of Kolmogorov spectra and the evolution towards thermal equilibrium follows self-similar dynamics. Simplified kinetic theory gives values for all characteristic exponents which are close to what is observed in lattice simulations. The resulting time for thermalization is long, and temperature at thermalization is low, $T \sim 100$ eV in the simple $\lambda \Phi^4$ inflationary model. Our results allow a straightforward generalization to realistic models.Comment: 4 pages, 3figures, LaTe

Linear and Non-Linear Kinetics in the Synthesis and Degradation of Acrylamide in Foods and Model Systems

Isothermal acrylamide formation in foods and asparagine-glucose model systems has ubiquitous features. On a time scale of about 60 min, at temperatures in the approximate range of 120−160

Breakfast glycaemic index and exercise: combined effects on adolescents' cognition

The aim of the present study was to examine the combined effects of breakfast glycaemic index (GI) and a mid-morning bout of exercise on adolescents’ cognitive function. Participants were randomly allocated to a high or low GI breakfast group in a mixed research design, where each participant completed two experimental trials (exercise and resting). Forty-two adolescents (12.4±0.5 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test; exercise trial) or continued to rest (resting trial) following consumption of either a high or low GI breakfast. A battery of cognitive function tests (visual search test, Stroop test and Sternberg paradigm) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 170±15 beats.min-1. On the complex level of the Stroop test, response times improved across the morning following the low GI breakfast on both the exercise and resting trials, though the improvement was greatest on the exercise trial. However, response times only improved on the resting trial following the high GI breakfast (p = 0.012). On the 5 letter level of the Sternberg paradigm, response times improved across the morning following the low GI breakfast (regardless of exercise) and only on the exercise trial following the high GI breakfast (p = 0.019). The findings of the present study suggest that the combined effects of breakfast GI and exercise in adolescents depend upon the component of cognitive function examined. A low GI breakfast and mid-morning bout of exercise were individually beneficial for response times on the Sternberg paradigm, whereas they conferred additional benefits for response times on the Stroop test

Anomalies, Dualities, and Topology of D=6 N=1 Superstring Vacua

We consider various aspects of compactifications of the Type I/heterotic $Spin(32)/\Z_2$ theory on K3. One family of such compactifications includes the standard embedding of the spin connection in the gauge group, and is on the same moduli space as the compactification of the heterotic $E_8\times E_8$ theory on K3 with instanton numbers (8,16). Another class, which includes an orbifold of the Type I theory recently constructed by Gimon and Polchinski and whose field theory limit involves some topological novelties, is on the moduli space of the heterotic $E_8\times E_8$ theory on K3 with instanton numbers (12,12). These connections between $Spin(32)/\Z_2$ and $E_8\times E_8$ models can be demonstrated by T duality, and permit a better understanding of non-perturbative gauge fields in the (12,12) model. In the transformation between $Spin(32)/\Z_2$ and $E_8\times E_8$ models, the strong/weak coupling duality of the (12,12) $E_8\times E_8$ model is mapped to T duality in the Type I theory. The gauge and gravitational anomalies in the Type I theory are canceled by an extension of the Green-Schwarz mechanism.Comment: 48 page