Non-extremal black hole solutions from the c-map

We construct new static, spherically symmetric non-extremal black hole solutions of four-dimensional ${\cal N}=2$ supergravity, using a systematic technique based on dimensional reduction over time (the c-map) and the real formulation of special geometry. For a certain class of models we actually obtain the general solution to the full second order equations of motion, whilst for other classes of models, such as those obtainable by dimensional reduction from five dimensions, heterotic tree-level models, and type-II Calabi-Yau compactifications in the large volume limit a partial set of solutions are found. When considering specifically non-extremal black hole solutions we find that regularity conditions reduce the number of integration constants by one half. Such solutions satisfy a unique set of first order equations, which we identify. Several models are investigated in detail, including examples of non-homogeneous spaces such as the quantum deformed $STU$ model. Though we focus on static, spherically symmetric solutions of ungauged supergravity, the method is adaptable to other types of solutions and to gauged supergravity.Comment: 57 pages. Minor changes to the introduction, typos corrected and references added. Accepted for publication in JHE

'Quarbs' and Efficiency in Spread Betting Markets: can you beat the book?

In this paper, we examine a relatively novel form of gambling, index (or spread) betting, that mirrors (and indeed overlaps with) practices in conventional financial markets. In this form of betting, a number of bookmakers quote a bid-offer spread about the result of some future event, and bettors are invited to buy (sell) at the top (bottom) end of the quoted spreads. We hypothesise that the existence of an outlying spread may provide uninformed traders with information that can be used to develop improved trading strategies. Using conditional moment tests on data from a popular spread betting market in the United Kingdom, we find that in the presence of a number of price-setters, the market mid-point is indeed a better predictor of asset values than the outlying price. We further show that this information can be used to develop trading strategies that lead to returns that are consistently positive and superior to those from noise trading and, in some cases, significantly so.

The Beta-Hyperbolic Secant (BHS) Distribution

The shape of a probability distribution is often summarized by the distribution's skewness and kurtosis. Starting from a symmetric parent density f on the real line, we can modify its shape (i.e. introduce skewness and in-/decrease kurtosis) if f is appropriately weighted. In particular, every density w on the interval (0; 1) is a specific weighting function. Within this work, we follow up a proposal of Jones (2004) and choose the Beta distribution as underlying weighting function w. Parent distributions like the Student-t, the logistic and the normal distribution have already been investigated in the literature. Based on the assumption that f is the density of a hyperbolic secant distribution, we introduce the Beta-hyperbolic secant (BHS) distribution. In contrast to the Beta-normal distribution and the to Beta-Student-t distribution, BHS densities are always unimodal and all moments exist. In contrast to the Beta-logistic distribution, the BHS distribution is more êexible regarding the range of skewness and leptokurtosis combinations. Moreover, we propose a generalization which nests both the Beta-logistic and the BHS distribution. Finally, the goodness-of-fit between all above-mentioned distributions is compared for glass fibre data and aluminium returns. --

Mechanistic studies of reactions of some platinum metal complexes

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SWOT Analysis of the horticultural farms in the Plovdiv region of Bulgaria

Agriculture/horticulture has traditionally been an important sector in the economy of Bulgaria. This paper reviews the changes in agriculture/horticulture in the Plovdiv region of Bulgaria after 1989 when the transition towards a free market economy began. In particular, it provides a review of the internal capabilities (strengths and weaknesses) of the horticultural farms and the impact upon them of the external environment (opportunities and threats). While many farmers regarded their experience as a strength, farmers having farms of different size identified additional different strengths, and different weaknesses and opportunities. Whereas, all of them were influenced by similar threats and the relative importance of these perceived threats did not varied depending upon the size of the farm

Integrative physiology of human aerobic fitness and the influence of the ACE I/Dp genotype

The search for genes that influence human performance and health constitutes a popular topic of current research. One such genetic constituent that has caused much interest over the last 20 years is the angiotensin converting enzyme insertion/deletion polymorphism (ACE I/Dp). There is much controversy in the literature regarding the role (if any) of this polymorphism as effects and effect size vary between populations of different origin and training status. The aim of this thesis was to analyse at the whole organism level whether skeletal muscle plasticity explains the association of the ACE I/D polymorphism with metabolic fitness. Regular endurance exercise reduces the risk of a plethora of diseases, but the exact molecular mechanisms are not fully understood – the ability of muscle to adapt to exercise stimulus is key. Trained individuals demonstrated clear physiological differences of aerobic processes such as increased oxygen usage, greater power output and reduced body fat that would be expected (T-Test: p<0.001). By contrast, when examining metabolite changes, at rest, in the local muscle there were few (n=6) nonpolar (lipid species) metabolite (assessed by mass spectrometry) differences between the trained and untrained. However, after an acute exercise bout working muscle in trained individuals displayed a significant up-regulation of (n=76) non-polar metabolites (Repeated ANOVA: p=0.0004), illustrating that training produces significant adaptations in substrate metabolism at the local level. Would there be a genetic component contributing towards these physiological and local muscle differences? Individuals with the ACE I-allele (insertion sequence) had increased capillary density, and there were significant differences in transcripts, together with both polar and non-polar metabolites in the untrained population at rest and following an acute exercise bout. These differences were lost in the trained population. In a different population (Swiss) capillary density was increased following a training programme in the absence of the I-allele – in contrast to the other population (British). However, gene expression response of important factors, to exercise was preserved. In conclusion, a trained population demonstrated enhanced non-polar metabolism in the working muscle after an exercise bout, and the dominant stimulus of regular exercise over-rides the influence of the ACE I/Dp. Nurture over-rides nature

Taxation and the Demand for Gambling: New Evidence from the United Kingdom.

In October 2001, the U.K. government implemented a dramatic shift in the taxation of gambling, resulting in a substantial decline in taxes levied on U.K. bookmakers. Using data before and after this event, we present econometric evidence on the demand response to this tax reduction. Our results suggest that the demand for bookmaker gambling is highly sensitive to taxation rates and that the decline in the rate of taxation led to a large increase in the demand for on-shore betting. We also find some evidence of price-induced substitution across different segments of the gambling industry. The U.K. policy initiative may provide useful information for policy makers in other countries who are contemplating changes in gambling taxation.