182 research outputs found
Greybody Factors and Charges in Kerr/CFT
We compute greybody factors for near extreme Kerr black holes in D=4 and D=5.
In D=4 we include four charges so that our solutions can be continuously
deformed to the BPS limit. In D=5 we include two independent angular momenta so
Left-Right symmetry is incorporated. We discuss the CFT interpretation of our
emission amplitudes, including the overall frequency dependence and the
dependence on all black hole parameters. We find that all additional parameters
can be incorporated Kerr/CFT, with central charge independent of U(1) charges.Comment: 27 pages. v2: typos fixed, references adde
A Note on Exact Solutions and Attractor Mechanism for Non-BPS Black Holes
We obtain two extremal, spherically symmetric, non-BPS black hole solutions
to 4D supergravity, one of which carries D2-D6 charges and the other carries
D0-D2-D4 charges. For the D2-D6 case, rather than solving the equations of
motion directly, we assume the form of the solution and then find that the
assumption satisfies the equations of motion and the constraint. Our D2-D6
solution is manifestly dual to the solution presented in 0710.4967. The
D0-D2-D4 solution is obtained by performing certain
duality transformations on the D0-D4 solution in 0710.4967.Comment: 20 pages, LaTe
Multi-Center non-BPS Black Holes - the Solution
We construct multi-center, non-supersymmetric four-dimensional solutions
describing a rotating anti-D6-D2 black hole and an arbitrary number of D4-D2-D0
black holes in a line. These solutions correspond to an arbitrary number of
extremal non-BPS black rings in a Taub-NUT space with a rotating three-charge
black hole in the middle. The positions of the centers are determined by
solving a set of "bubble" or "integrability" equations that contain cubic
polynomials of the inter-center distance, and that allow scaling solutions even
when the total four-dimensional angular momentum of the scaling centers is
non-zero.Comment: 16 pages, LaTe
Constituent Model of Extremal non-BPS Black Holes
We interpret extremal non-BPS black holes in four dimensions as threshold
bound states of four 1/2-BPS constituents. We verify the no-force condition for
each of the primitive constituents in the probe approximation. Our computations
are for a seed solution with charges and equal -fields, but
symmetries extend the result to any U-dual frame. We make the constituent model
for the system explicit, and also discuss a duality frame where the
constituents are branes at angles. We demonstrate stability of the
constituent model in the weak coupling description of the constituent D-branes.
We discuss the relation between the BPS and non-BPS branches of configuration
space.Comment: 29 pages; v2. references adde
Epidemiological, clinical and immunohistochemical aspects of canine lymphoma in the region of Porto Alegre, Brazil
This paper describes the epidemiological, clinical and immunohistochemical characteristics of canine lymphomas diagnosed in the region of Porto Alegre, Brazil. Thirty dogs were enrolled in the study; most of them were male (60%), mixed-breed (23%) and middle-aged or older. The majority (87%) of affected dogs showed the multicentric form. The B-cell phenotype was most frequently detected (62%); 37% of the animals were in clinical stage IV, and 83% were classified as sub-stage "b". Lymphadenopathy was observed in 67% of the cases, and dyspnea, prostration, decreased appetite and vomiting were the most common clinical signs encountered. Anemia was a frequently encountered laboratory alteration (57%), as were leukocytosis (40%), thrombocytopenia (33%), lymphopenia (30%), hyperglobulinemia (20%) and hypercalcemia (13%). The results of this study indicate that the clinical features of dogs with lymphoma in the region of Porto Alegre are similar to those observed worldwide
First-order flow equations for extremal and non-extremal black holes
We derive a general form of first-order flow equations for extremal and
non-extremal, static, spherically symmetric black holes in theories with
massless scalars and vectors coupled to gravity. By rewriting the action as a
sum of squares a la Bogomol'nyi, we identify the function governing the
first-order gradient flow, the `generalised superpotential', which reduces to
the `fake superpotential' for non-supersymmetric extremal black holes and to
the central charge for supersymmetric black holes. For theories whose scalar
manifold is a symmetric space after a timelike dimensional reduction, we
present the condition for the existence of a generalised superpotential. We
provide examples to illustrate the formalism in four and five spacetime
dimensions.Comment: 27 pages, v2: small changes, referencing and misprints corrected, v3:
text updated and a reference added to match the JHEP versio
First-order attractor flow equations for supersymmetric black rings in N=2, D=5 supergravity
In this paper we investigate the attractor mechanism in the five dimensional
low energy supergravity theory corresponding to M-theory compactified on a
Calabi-Yau threefold . Using very special geometry, we derive the general
first-order attractor flow equations for BPS and non-BPS solutions in
five-dimensional Gibbons-Hawking spaces. Especially, considering the
supersymmetric solution, we obtain the first-order flow equations for
supersymmetric (multi)black rings. We also solve the flow equations and discuss
some properties of the solutions of flow equations.Comment: 18 pages, no figure, the references are adde
Molecular characterization of Listeria monocytogenes isolated from animal products in a city of Northern Brazil
Listeria monocytogenes, a foodborne pathogen causes listeriosis, a fatal disease in about 30% of cases that affects mainly immunocompromised persons. The aim of this research was to characterize L. monocytogenes pulsed-field gel electrophoresis (PFGE) types isolated from meat products collected at public markets in Araguaina city, TO. Sixty samples of raw ground beef and frescal sausage were analyzed during the second half of 2008. Five out of 30 samples (16.7%) of raw ground beef tested positive for L. monocytogenes, three of which were classified as serotype 1/2b and two as serotype 4b. Among the 30 samples of sausage collected, two strains of L. monocytogenes were isolated (6.7%), one of them belonging to serotype 1/2a and the other belonging to serotype 1/2b. The restriction enzymes used were ApaI and SmaI. Similarities among the strains were determined by Dice coefficient. The macro restriction profile obtained by using SmaI enzyme allowed the distribution of seven strains in two clusters, two pulsotypes and two subtypes. The result indicates that L. monocytogenes isolates, belonging to serotype 4b, 1/2a and 1/2b, are strongly correlated within the same serotype group, and in some cases among different serotypes, suggesting that they have a common source
Modelling the probability of meeting IUCN Red List criteria to support reassessments
Comparative extinction risk analysis—which predicts species extinction risk from correlation with traits or geographical characteristics—has gained research attention as a promising tool to support extinction risk assessment in the IUCN Red List of Threatened Species. However, its uptake has been very limited so far, possibly because existing models only predict a species' Red List category, without indicating which Red List criteria may be triggered. This prevents such approaches to be integrated into Red List assessments. We overcome this implementation gap by developing models that predict the probability of species meeting individual Red List criteria. Using data on the world's birds, we evaluated the predictive performance of our criterion-specific models and compared it with the typical criterion-blind modelling approach. We compiled data on biological traits (e.g. range size, clutch size) and external drivers (e.g. change in canopy cover) often associated with extinction risk. For each specific criterion, we modelled the relationship between extinction risk predictors and species' Red List category under that criterion using ordinal regression models. We found criterion-specific models were better at identifying threatened species compared to a criterion-blind model (higher sensitivity), but less good at identifying not threatened species (lower specificity). As expected, different covariates were important for predicting extinction risk under different criteria. Change in annual temperature was important for criteria related to population trends, while high forest dependency was important for criteria related to restricted area of occupancy or small population size. Our criteria-specific method can support Red List assessors by producing outputs that identify species likely to meet specific criteria, and which are the most important predictors. These species can then be prioritised for re-evaluation. We expect this new approach to increase the uptake of extinction risk models in Red List assessments, bridging a long-standing research-implementation gap
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