183 research outputs found
Recommendations for the Use of Pencillin in the Treatment of Bovine Mastitis
Studies on the use of penicillin in the treatment of mastitis are not yet complete. The results obtained to date are sufficiently encouraging, however, to warrant a preliminary statement regarding dosage and method of administration, although research still in progress may later result in minor changes in these recommendations
Alpha-states in de Sitter space
Field theory in de Sitter space admits a one-parameter family of vacua
determined by a superselection parameter alpha. Of these vacua, the Euclidean
vacuum uniquely extrapolates to the vacuum of flat Minkowski space. States
which resemble the alpha-vacua can be constructed as excitations above the
Euclidean vacuum. Such states have modes alpha(k) which decay faster that
k^{(1-d)/2}. Fields in such states exhibit non-local correlations when examined
from the perspective of fields in the Euclidean vacuum. The dynamics of such
entangled states are fully consistent. If an alpha-state with properties that
interpolate between an alpha-vacuum and the Euclidean vacuum were the initial
condition for inflation, a signature for this may be found in a momentum
dependent correction to the inflationary power spectrum. The functional
formalism, which provides the tool for examining physics in an alpha-state,
extends to fields of other spin. In particular, the extension to spin-2 may
proffer a new class of infrared modifications to gravitational interactions.
The implications of superselection sectors for the landscape of string vacua
are briefly discussed.Comment: 28 pages, LaTe
Black hole determinants and quasinormal modes
We derive an expression for functional determinants in thermal spacetimes as
a product over the corresponding quasinormal modes. As simple applications we
give efficient computations of scalar determinants in thermal AdS, BTZ black
hole and de Sitter spacetimes. We emphasize the conceptual utility of our
formula for discussing `1/N' corrections to strongly coupled field theories via
the holographic correspondence.Comment: 28 pages. v2: slightly improved exposition, references adde
Lectures on string theory and cosmology
In these lectures I review recent attempts to apply string theory to
cosmology, including string cosmology and various models of brane cosmology. In
addition, the review includes an introduction to inflation as well as a
discussion of transplanckian signatures. I also provide a critical discussion
of the possible role of holography. The material is based on lectures given in
January 2004 at the RTN String School in Barcelona, but also contain some
additional material.Comment: Lectures given in January 2004 at the RTN Barcelona String School, 50
pages, 9 figure
Observational Signatures and Non-Gaussianities of General Single Field Inflation
We perform a general study of primordial scalar non-Gaussianities in single
field inflationary models in Einstein gravity. We consider models where the
inflaton Lagrangian is an arbitrary function of the scalar field and its first
derivative, and the sound speed is arbitrary. We find that under reasonable
assumptions, the non-Gaussianity is completely determined by 5 parameters. In
special limits of the parameter space, one finds distinctive ``shapes'' of the
non-Gaussianity. In models with a small sound speed, several of these shapes
would become potentially observable in the near future. Different limits of our
formulae recover various previously known results.Comment: 53 pages, 5 figures; v3, minor revision, JCAP version; v4, numerical
coefficients corrected in Appendix B, discussion on consistency condition
revise
Observational Signatures and Non-Gaussianities of General Single Field Inflation
We perform a general study of primordial scalar non-Gaussianities in single
field inflationary models in Einstein gravity. We consider models where the
inflaton Lagrangian is an arbitrary function of the scalar field and its first
derivative, and the sound speed is arbitrary. We find that under reasonable
assumptions, the non-Gaussianity is completely determined by 5 parameters. In
special limits of the parameter space, one finds distinctive ``shapes'' of the
non-Gaussianity. In models with a small sound speed, several of these shapes
would become potentially observable in the near future. Different limits of our
formulae recover various previously known results.Comment: 53 pages, 5 figures; v3, minor revision, JCAP version; v4, numerical
coefficients corrected in Appendix B, discussion on consistency condition
revise
Age- and region-specific hepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review
Toy M, Önder FO, Wörmann T, et al. Age- and region-specific hepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review. BMC infectious diseases. 2011;11(1): 337.BACKGROUND: To provide a clear picture of the current hepatitis B situation, the authors performed a systematic review to estimate the age- and region-specific prevalence of chronic hepatitis B (CHB) in Turkey. METHODS: A total of 339 studies with original data on the prevalence of hepatitis B surface antigen (HBsAg) in Turkey and published between 1999 and 2009 were identified through a search of electronic databases, by reviewing citations, and by writing to authors. After a critical assessment, the authors included 129 studies, divided into categories: 'age-specific'; 'region-specific'; and 'specific population group'. To account for the differences among the studies, a generalized linear mixed model was used to estimate the overall prevalence across all age groups and regions. For specific population groups, the authors calculated the weighted mean prevalence. RESULTS: The estimated overall population prevalence was 4.57, 95% confidence interval (CI): 3.58, 5.76, and the estimated total number of CHB cases was about 3.3 million. The outcomes of the age-specific groups varied from 2.84, (95% CI: 2.60, 3.10) for the 0-14-year olds to 6.36 (95% CI: 5.83, 6.90) in the 25-34-year-old group. CONCLUSION: There are large age-group and regional differences in CHB prevalence in Turkey, where CHB remains a serious health problem
Design and descriptive epidemiology of the Infectious Diseases of East African Livestock (IDEAL) project, a longitudinal calf cohort study in western Kenya
BACKGROUND: There is a widely recognised lack of baseline epidemiological data on the dynamics and impacts of infectious cattle diseases in east Africa. The Infectious Diseases of East African Livestock (IDEAL) project is an epidemiological study of cattle health in western Kenya with the aim of providing baseline epidemiological data, investigating the impact of different infections on key responses such as growth, mortality and morbidity, the additive and/or multiplicative effects of co-infections, and the influence of management and genetic factors. A longitudinal cohort study of newborn calves was conducted in western Kenya between 2007-2009. Calves were randomly selected from all those reported in a 2 stage clustered sampling strategy. Calves were recruited between 3 and 7 days old. A team of veterinarians and animal health assistants carried out 5-weekly, clinical and postmortem visits. Blood and tissue samples were collected in association with all visits and screened using a range of laboratory based diagnostic methods for over 100 different pathogens or infectious exposures. RESULTS: The study followed the 548 calves over the first 51 weeks of life or until death and when they were reported clinically ill. The cohort experienced a high all cause mortality rate of 16% with at least 13% of these due to infectious diseases. Only 307 (6%) of routine visits were classified as clinical episodes, with a further 216 reported by farmers. 54% of calves reached one year without a reported clinical episode. Mortality was mainly to east coast fever, haemonchosis, and heartwater. Over 50 pathogens were detected in this population with exposure to a further 6 viruses and bacteria. CONCLUSION: The IDEAL study has demonstrated that it is possible to mount population based longitudinal animal studies. The results quantify for the first time in an animal population the high diversity of pathogens a population may have to deal with and the levels of co-infections with key pathogens such as Theileria parva. This study highlights the need to develop new systems based approaches to study pathogens in their natural settings to understand the impacts of co-infections on clinical outcomes and to develop new evidence based interventions that are relevant
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