Exact monopole instantons and cosmological solutions in string theory from abelian dimensional reduction

We compute the exact string vacuum backgrounds corresponding to the non-compact coset theory $SU(2,1)/SU(2)$. The conformal field theory defined by the level $k= 4$ results in a five dimensional singular solution that factorizes in an asymptotic region as the linear dilaton solution and a $S^3$ model. It presents two abelian compact isometries that allow to reinterpreting it from a four dimensional point of view as a stationary and magnetically charged space-time resembling in some aspects the Kerr-Newman solution of general relativity. The $k=\frac{13}{7}$ theory on the other hand describes a cosmological solution that interpolates between a singular phase at short times and a $S^1 \times S^2$ universe after some planckian times.Comment: 18 pages, section 5 replaced by 5 and 6, references added; to appear in Phys. Rev.

Using ambulatory care sensitive hospitalisations to analyse the effectiveness of primary care services in Mexico.

Ambulatory care sensitive hospitalisations (ACSH) have been widely used to study the quality and effectiveness of primary care. Using data from 248 general hospitals in Mexico during 2001-2011 we identify 926,769 ACSHs in 188 health jurisdictions before and during the health insurance expansion that took place in this period, and estimate a fixed effects model to explain the association of the jurisdiction ACSH rate with patient and community factors. National ACSH rate increased by 50%, but trends and magnitude varied at the jurisdiction and state level. We find strong associations of the ACSH rate with socioeconomic conditions, health care supply and health insurance coverage even after controlling for potential endogeneity in the rolling out of the insurance programme. We argue that the traditional focus on the increase/decrease of the ACSH rate might not be a valid indicator to assess the effectiveness of primary care in a health insurance expansion setting, but that the ACSH rate is useful when compared between and within states once the variation in insurance coverage is taken into account as it allows the identification of differences in the provision of primary care. The high heterogeneity found in the ACSH rates suggests important state and jurisdiction differences in the quality and effectiveness of primary care in Mexico

Health care utilisation amongst older adults with sensory and cognitive impairments in Europe.

Worldwide, the high prevalence of multiple chronic conditions amongst older population has led to increased utilisation of health care and rising associated costs, becoming a major public health concern. Hearing, vision and cognitive disorders are common chronic conditions amongst older Europeans and recent studies have documented its high co-occurrence. While it has been shown separately that suffering either mental disorders or sensory (hearing and vision) impairments is associated with higher health care utilisation, the association between health care utilisation and the interaction of these conditions has received little attention in the literature. Therefore, using four waves of the Survey of Health, Ageing and Retirement in Europe (SHARE), this study applies the correlated random effects method to the negative binomial and finite mixture models to analyse the extent to which the interaction of cognitive and sensory impairments is associated with health care use. We found that individuals with cognitive impairment tend to have more hospitalisations. The finite mixture approach indicates a positive association between sensory impairment and the number of hospitalisations amongst low users of health care. Additionally, our findings suggest a positive association between suffering both impairments at the same time and the number of doctor and GP visits

Sexual Risks and Concerns about AIDS among Adolescents in Anguilla

Concerns regarding HIV/AIDS infection and the health risk behaviours among youth in the Caribbean are growing. Considering that approximately 30% of the Caribbean\u27s population falls between the ages of 10 to 24, there is considerable need for research on youth in this region. This paper reports findings regarding the sexual risks and concerns about AIDS among 1,225 enrolled school students in Anguilla, drawn from self-administered health surveys conducted in 2002. Although over 40% of youth reported lifetime alcohol use, experience with other drugs was moderate. Males initiated sexual activity at a much younger median age than females (11 years for males vs. 14 years for females), and were twice as likely to have had sexual intercourse. In a multivariate logistic regression model, being sexually active was predicted by male gender (p=.000), recent substance use (p=.000), recent depression (p=.018), and a history of physical (p=.025) and sexual (p=.000) abuse. Only 22% of sexually active youth under 12 years of age reported using condoms at last intercourse, compared to 71% of those 13 and over. Older sexually active youth were also much more likely than younger ones to express ongoing concern about becoming infected with HIV. Implications for needed HIV/AIDS-prevention interventions are discussed

Exploring the therapeutic alliance and race from sports psychologists' and athletes' lived experiences: A pilot study

The therapeutic alliance has been explored widely within therapy literature but more research is necessary on the sport and exercise psychology client dyad. The racial/cultural identity development model and Rogers's (1957) six core conditions provide the conceptual and theoretical framework for this pilot qualitative study, which seeks to explore the building process in therapeutic relationships within cross-racial sport and exercise psychology. The perspectives of four black athletes of mixed descent and seven sport and exercise psychologists from diverse backgrounds (Arab = 1, Black British = 3, White British = 3) were considered. One-hour semi-structured interviews were analysed using an inductive thematic analysis. This yielded the following themes for athletes: lack of disclosure, racial impact on alliance, desired characteristics and experience. For sport and exercise psychologists these themes included therapeutic alliance building blocks, creating safe spaces and the racial impact of disclosure. Recommendations for building the process in cross-racial dyads are explored based on the participants' comments. The findings are discussed and areas for future research are explored based on these main themes.publishedVersio

A link between hurricane-induced tree sprouting, high stem density and short canopy in tropical dry forest

The physiognomy of Caribbean dry forest is shorter, denser and contains a greater proportion of multi-stemmed trees than other neotropical dry forests. Our previous research, conducted after Hurricane Georges in 1998, has shown that dry forest trees sprout near the base following hurricane disturbance, even if the trees have not incurred structural damage. However, for these hurricane-induced sprouts to contribute to the physiognomy of the forest, they must grow and survive. We followed sprout dynamics and stem mortality on 1,407 stems from 1998, after Hurricane Georges, until 2005. The number of surviving sprouts and the proportion of sprouting stems decreased during the 7-year period, but the sprouting rate was still 3-fold higher and the proportion of sprouting stems 5-fold higher than before the hurricane. Mortality of non-sprouting stems (15.4%) was about the same as for sprouting stems (13.9%) after 7 years. The mean length of the dominant sprout surpassed 1.6 m by 2005, with over 13% of the dominant sprouts reaching subcanopy height. Sprout growth and survival varied among species. These results demonstrate that, despite some thinning, hurricane-induced sprouts survive and grow and that the unique physiognomic characteristic of Caribbean dry forests is related to hurricane disturbance

Structural response of Caribbean dry forests to hurricane winds: a case study from Guanica Forest, Puerto Rico

Aim Tropical dry forests in the Caribbean have an uniquely short, shrubby structure with a high proportion of multiple-stemmed trees compared to dry forests elsewhere in the Neotropics. Previous studies have shown that this structure can arise without the loss of main stems from cutting, grazing, or other human intervention. The Caribbean has a high frequency of hurricanes, so wind may also influence forest stature. Furthermore, these forests also tend to grow on soils with low amounts of available phosphorus, which may also influence structure. The objective of this study was to assess the role of high winds in structuring dry forest, and to determine whether soil nutrient pools influence forest response following hurricane disturbance. Location Guánica Forest, Puerto Rico. Methods Over 2000 stems in five plots were sampled for hurricane effects within 1 week after Hurricane Georges impacted field sites in 1998. Sprout initiation, growth, and mortality were analysed for 1407 stems for 2 years after the hurricane. Soil nutrient pools were measured at the base of 456 stems to assess association between nutrients and sprout dynamics. Results Direct effects of the hurricane were minimal, with stem mortality at \u3c 2% and structural damage to stems at 13%, although damage was biased toward stems of larger diameter. Sprouting response was high – over 10 times as many trees had sprouts after the hurricane as before. The number of sprouts on a stem also increased significantly. Sprouting was common on stems that only suffered defoliation or had no visible effects from the hurricane. Sprout survival after 2 years was also high (\u3e 86%). Soil nutrient pools had little effect on forest response as a whole, but phosphorus supply did influence sprout dynamics on four of the more common tree species. Main conclusions Hurricanes are able to influence Caribbean tropical dry forest structure by reducing average stem diameter and basal area and generating significant sprouting responses. New sprouts, with ongoing survival, will maintain the high frequency of multi-stemmed trees found in this region. Sprouting is not limited to damaged stems, indicating that trees are responding to other aspects of high winds, such as short-term gravitational displacement or sway. Soil nutrients play a secondary role in sprouting dynamics of a subset of species. The short, shrubby forest structure common to the Caribbean can arise naturally as a response to hurricane winds

Regional Forest Types - Tropical Dry Forests

Tropical dry forests occur in nearly every tropical country. This forest type provides critical habitat for large mammals and migratory birds, and patches of dry forest can support a high proportion of endemic plant and animal species, as well as being highly valued for agricultural and production forestry uses. Consequently, conservation and understanding of these forests need emphasis, yet conservationists and scientists still frequently overlook this ecosystem