Massive Dualities in Six Dimensions

We study compactifications of string theory and M-theory to six dimensions with background fluxes. The nonzero fluxes lead to additional mass parameters. We derive the S- and T-duality rules for the corresponding (massive) supergravity theories. Specifically, we investigate the massive T-duality between Type IIA superstring theory compactified on K3 with background fluxes and Type IIB superstring theory compactified on K3. Furthermore, we generalise to the massive case the 6D 'string-string' S-duality between M-theory on K3 x S^1 and the Heterotic String on T^4. Whereas in the case of massive T--duality the mass parameters are in the fundamental representation of the U-duality group O(4,20) we find that in the case of massive S-duality they are in the 3-index antisymmetric representation. In the latter case the mass parameters involved extend those of Kaloper and Myers. We apply our duality rules to massive brane solutions, like the domain wall solutions corresponding to the mass parameters and find new massive brane solutions. Finally, we discuss the higher-dimensional interpretation of the dualities and brane solutions.Comment: 28 page

N=31 is not IIB

We adapt the spinorial geometry method to investigate supergravity backgrounds with near maximal number of supersymmetries. We then apply the formalism to show that the IIB supergravity backgrounds with 31 supersymmetries preserve an additional supersymmetry and so they are maximally supersymmetric. This rules out the existence of IIB supergravity preons.Comment: 7 page

Geometry of all supersymmetric type I backgrounds

We find the geometry of all supersymmetric type I backgrounds by solving the gravitino and dilatino Killing spinor equations, using the spinorial geometry technique, in all cases. The solutions of the gravitino Killing spinor equation are characterized by their isotropy group in Spin(9,1), while the solutions of the dilatino Killing spinor equation are characterized by their isotropy group in the subgroup Sigma(P) of Spin(9,1) which preserves the space of parallel spinors P. Given a solution of the gravitino Killing spinor equation with L parallel spinors, L = 1,2,3,4,5,6,8, the dilatino Killing spinor equation allows for solutions with N supersymmetries for any 0 < N =< L. Moreover for L = 16, we confirm that N = 8,10,12,14,16. We find that in most cases the Bianchi identities and the field equations of type I backgrounds imply a further reduction of the holonomy of the supercovariant connection. In addition, we show that in some cases if the holonomy group of the supercovariant connection is precisely the isotropy group of the parallel spinors, then all parallel spinors are Killing and so there are no backgrounds with N < L supersymmetries.Comment: 73 pages. v2: minor changes, references adde

M-theory and gauged supergravities

We present a pedagogical discussion of the emergence of gauged supergravities from M-theory. First, a review of maximal supergravity and its global symmetries and supersymmetric solutions is given. Next, different procedures of dimensional reduction are explained: reductions over a torus, a group manifold and a coset manifold and reductions with a twist. Emphasis is placed on the consistency of the truncations, the resulting gaugings and the possibility to generate field equations without an action. Using these techniques, we construct a number of gauged maximal supergravities in diverse dimensions with a string or M-theory origin. One class consists of the CSO gaugings, which comprise the analytic continuations and group contractions of SO(n) gaugings. We construct the corresponding half-supersymmetric domain walls and discuss their uplift to D- and M-brane distributions. Furthermore, a number of gauged maximal supergravities are constructed that do not have an action. (C) 2005 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.</p

Strengthening of Parenthood; Developing a Life Skills Questionnaire for Dutch Parents (LSQ-P)

AbstractLife skills of parents have a positive effect on the wellbeing of parents and development of children. Currently, no reliable instrument is available to measure these skills. This study was set up to develop a questionnaire for assessing parents’ life skills. The questionnaire was developed for professionals who are working with parents and for building behavioral interventions enhancing the wellbeing of parents. A pilot research using a translation of the Life Skills Scale (Erawan, 2010) was conducted. Construct validity and reliability by means of confirmatory factor analysis of nine scales were examined in a sample of 133 Dutch parents and reliability of the scales in terms of Cronbach's alpha was examined. Evidence for construct validity of the scales was found. Reliability coefficients were satisfactory for the scales Critical thinking, Social responsibility, Interpersonal relationships, Decision making, Self-awareness, and Creative thinking. Reliability coefficients were good for Empathy and Self-esteem. The LSQ-P can be used in social work practice as an assessment tool to measure strengths and weaknesses regarding life skills of parents. More attention for developing life skills of parents is necessary in order to increase their wellbeing. Implications for health promotion among parents are discussed. Suggestions for further research and development of the scales are outlined

Reduction of Coxiella burnetii prevalence by vaccination of goats and sheep, the Netherlands

Recently, the number of human Q fever cases in the Netherlands increased dramatically. In response to this increase, dairy goats and dairy sheep were vaccinated against Coxiella burnetii. All pregnant dairy goats and dairy sheep in herds positive for Q fever were culled. We identified the effect of vaccination on bacterial shedding by small ruminants. On the day of culling, samples of uterine fluid, vaginal mucus, and milk were obtained from 957 pregnant animals in 13 herds. Prevalence and bacterial load were reduced in vaccinated animals compared with unvaccinated animals. These effects were most pronounced in animals during their first pregnancy. Results indicate that vaccination may reduce bacterial load in the environment and human exposure to C. burnetii

Maximally supersymmetric G-backgrounds of IIB supergravity

We classify the geometry of all supersymmetric IIB backgrounds which admit the maximal number of $G$-invariant Killing spinors. For compact stability subgroups $G=G_2, SU(3)$ and SU(2), the spacetime is locally isometric to a product $X_n\times Y_{10-n}$ with $n=3,4,6$, where $X_n$ is a maximally supersymmetric solution of a $n$-dimensional supergravity theory and $Y_{10-n}$ is a Riemannian manifold with holonomy $G$. For non-compact stability subgroups, G=K\ltimes\bR^8, $K=Spin(7)$, SU(4), $Sp(2)$, $SU(2)\times SU(2)$ and $\{1\}$, the spacetime is a pp-wave propagating in an eight-dimensional manifold with holonomy $K$. We find new supersymmetric pp-wave solutions of IIB supergravity.Comment: 22 page

The Classification of Highly Supersymmetric Supergravity Solutions

The spinorial geometry method is an effective method for constructing systematic classifications of supersymmetric supergravity solutions. Recent work on analysing highly supersymmetric solutions in type IIB supergravity using this method is reviewed [arXiv:hep-th/0606049, arXiv:0710.1829]. It is shown that all supersymmetric solutions of IIB supergravity with more than 28 Killing spinors are locally maximally supersymmetric.Comment: 23 pages, latex. To appear in the proceedings of the Special Metrics and Supersymmetry conference at Universidad del Pais Vasco, May 2008. References correcte