241 research outputs found
Communicative Competence and Local Theories of Argumentation: The Case of Academic Citational Practices
Lodged in the throat: Internal infinities and AdS/CFT
In the context of AdS3/CFT2, we address spacetimes with a certain sort of
internal infinity as typified by the extreme BTZ black hole. The internal
infinity is a null circle lying at the end of the black hole's infinite throat.
We argue that such spacetimes may be described by a product CFT of the form
CFT-L * CFT-R, where CFT-R is associated with the asymptotically AdS boundary
while CFT-L is associated with the null circle. Our particular calculations
analyze the CFT dual of the extreme BTZ black hole in a linear toy model of
AdS3/CFT2. Since the BTZ black hole is a quotient of AdS3, the dual CFT state
is a corresponding quotient of the CFT vacuum state. This state turns out to
live in the aforementioned product CFT. We discuss this result in the context
of general issues of AdS/CFT duality and entanglement entropy.Comment: 11 pages, 2 figures; v2 - some typos corrected, minor revision
A Step Beyond the Bounce: Bubble Dynamics in Quantum Phase Transitions
We study the dynamical evolution of a phase interface or bubble in the
context of a \lambda \phi^4 + g \phi^6 scalar quantum field theory. We use a
self-consistent mean-field approximation derived from a 2PI effective action to
construct an initial value problem for the expectation value of the quantum
field and two-point function. We solve the equations of motion numerically in
(1+1)-dimensions and compare the results to the purely classical evolution. We
find that the quantum fluctuations dress the classical profile, affecting both
the early time expansion of the bubble and the behavior upon collision with a
neighboring interface.Comment: 12 pages, multiple figure
General Brane Geometries from Scalar Potentials: Gauged Supergravities and Accelerating Universes
We find broad classes of solutions to the field equations for d-dimensional
gravity coupled to an antisymmetric tensor of arbitrary rank and a scalar field
with non-vanishing potential. Our construction generates these configurations
from the solution of a single nonlinear ordinary differential equation, whose
form depends on the scalar potential. For an exponential potential we find
solutions corresponding to brane geometries, generalizing the black p-branes
and S-branes known for the case of vanishing potential. These geometries are
singular at the origin with up to two (regular) horizons. Their asymptotic
behaviour depends on the parameters of the model. When the singularity has
negative tension or the cosmological constant is positive we find
time-dependent configurations describing accelerating universes. Special cases
give explicit brane geometries for (compact and non-compact) gauged
supergravities in various dimensions, as well as for massive 10D supergravity,
and we discuss their interrelation. Some examples lift to give new solutions to
10D supergravity. Limiting cases with a domain wall structure preserve part of
the supersymmetries of the vacuum. We also consider more general potentials,
including sums of exponentials. Exact solutions are found for these with up to
three horizons, having potentially interesting cosmological interpretation. We
give several additional examples which illustrate the power of our techniques.Comment: 54 pages, 6 figures. Uses JHEP3. Published versio
Domain Walls of D=8 Gauged Supergravities and their D=11 Origin
Performing a Scherk-Schwarz dimensional reduction of D=11 supergravity on a
three-dimensional group manifold we construct five D=8 gauged maximal
supergravities whose gauge groups are the three-dimensional (non-)compact
subgroups of SL(3,R). These cases include the Salam-Sezgin SO(3) gauged
supergravity. We construct the most general half-supersymmetric domain wall
solutions to these five gauged supergravities. The generic form is a triple
domain wall solution whose truncations lead to double and single domain wall
solutions. We find that one of the single domain wall solutions has zero
potential but nonzero superpotential.
Upon uplifting to 11 dimensions each domain wall becomes a purely
gravitational 1/2 BPS solution. The corresponding metric has a 7+4 split with a
Minkowski 7-metric and a 4-metric that corresponds to a gravitational
instanton. These instantons generalize the SO(3) metric of Belinsky, Gibbons,
Page and Pope (which includes the Eguchi-Hanson metric) to the other Bianchi
types of class A.Comment: 23 pages, 1 figure, minor changes, references adde
Comparação entre difração de raios X e "mĂ©todo do furo cego" para medição de tensĂ”es residuais em barras cilĂndricas
Quantitative analyses and modelling to support achievement of the 2020 goals for nine neglected tropical diseases
Quantitative analysis and mathematical models are useful tools in informing strategies to control or eliminate disease. Currently, there is an urgent need to develop these tools to inform policy to achieve the 2020 goals for neglected tropical diseases (NTDs). In this paper we give an overview of a collection of novel model-based analyses which aim to address key questions on the dynamics of transmission and control of nine NTDs: Chagas disease, visceral leishmaniasis, human African trypanosomiasis, leprosy, soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. Several common themes resonate throughout these analyses, including: the importance of epidemiological setting on the success of interventions; targeting groups who are at highest risk of infection or re-infection; and reaching populations who are not accessing interventions and may act as a reservoir for infection,. The results also highlight the challenge of maintaining elimination 'as a public health problem' when true elimination is not reached. The models elucidate the factors that may be contributing most to persistence of disease and discuss the requirements for eventually achieving true elimination, if that is possible. Overall this collection presents new analyses to inform current control initiatives. These papers form a base from which further development of the models and more rigorous validation against a variety of datasets can help to give more detailed advice. At the moment, the models' predictions are being considered as the world prepares for a final push towards control or elimination of neglected tropical diseases by 2020
Soccer and homosexuality: the conflicts that lie within the affective game of the coach-adolescent athlete relationship
Discussions regarding homosexuality within a sports context are mediated by emotional nuances, especially in the world of soccer, where practitioners are required to have attributes such as strength, masculinity and aggressiveness. As a consequence, this work aimed to analyze the symbolic representation of homosexual relationships between
adolescent soccer players and their coaches; and, furthermore, to understand the intention behind homoerotic relationships that are established between members of the management team and its players. In this study, researchers used the life history methodology, with participation from three adolescent athletes, ages 14, 15 and 16, and three former athletes, ages 26, 28 and 45, who we called speakers. Based on the collection and analysis of research participantsâ testimonies, homosexual relations were found to have occurred between athletes and coaches, or between athletes and other members of the management team, as a part of a âsocial contractâ that is exclusively linked to their professional objectives. These relationships appear to be purely objective; authentic affective links are absent, due apparently to the transient nature of the athletes in these groups. Too, this context is usually marked by the athleteâs physical and emotional vulnerability, and the agreements he makes within this context are accompanied with moral dilemmas, because such adolescents idealize the coach as a paternal archetype.âFutebol e homossexualidade: Os conflitos que se encontram dentro do jogo afetivo da relação treinador-atleta
adolescente.â As discussĂ”es a respeito da homossexualidade no contexto esportivo sĂŁo mediadas por nuanças emocionais,
especialmente no mundo do futebol que exige de seus praticantes atributos de força, virilidade e agressividade. Por este
motivo este trabalho teve como objetivos diagnosticar existĂȘncia de relaçÔes homossexuais entre atletas adolescentes da
modalidade de futebol e seus técnicos e sua representação simbólica e ainda, compreender a intencionalidade das relaçÔes
homoafetivas que se estabelecem entre componentes da equipe diretiva e os jogadores. Esta pesquisa Ă© de natureza qualitativa
e a tĂ©cnica adotada foi a âhistĂłria de vidaâ e a participação de trĂȘs atletas adolescentes em atividade, com idade de
14, 15 e 16 anos e trĂȘs ex-atletas profissionais, com idades 26, 28 e 45 anos serviram de base metodolĂłgica. A partir da
anålise e tratamento dos depoimentos verificou-se que ocorreram relaçÔes homossexuais nas categorias de base envolvendo
técnico e atleta, ou com outros membros da equipe diretiva, como parte dos contratos sociais, ligados exclusivamente a
objetivos profissionais. Estas relaçÔes parecem ser puramente objetais, nĂŁo parecendo existir vĂnculos afetivos duradouros,
aparentemente, devido à natureza transitória de atletas nesses grupos. Também, nesses ambientes, muitas vezes marcados
pela vulnerabilidade fĂsica e emocional dos atletas, os acertos para as relaçÔes homossexuais sĂŁo permeadas por dilemas
morais, tendo em vista que os atletas adolescentes idealizam o treinador como o arquĂ©tipo paterno ideal.âEl fĂștbol y la homosexualidad: Los conflictos que se encuentran dentro del juego afectivo de la relaciĂłn
atleta-entrenador de los adolescentes.â Las discusiones sobre la homosexualidad en contexto deportivo estĂĄn mediadas por
matices emocionales, sobre todo en el mundo del fĂștbol que exige a sus jugadores atributos como la fuerza, la virilidad y los jugadores. En este estudio, los investigadores utilizaron la metodologĂa de la historia de vida, con la participaciĂłn de
tres atletas adolescentes, con 14, 15 y 16 años, y tres ex atletas con 26, 28 y 45 años, que llamamos âoradoresâ. Basado
en la recogida y anĂĄlisis de testimonios de participantes en la investigaciĂłn, se encontrĂł que las relaciones homosexuales
que se han producido entre los atletas y entrenadores, o entre atletas y otros miembros del equipo de gestiĂłn, son como
parte de un âcontrato socialâ que estĂĄ vinculado exclusivamente a sus objetivos profesionales. Estas relaciones parecen
ser solamente como un objeto; porque a veces no hay vĂnculos afectivos autĂ©nticos, debido aparentemente a la naturaleza
transitoria de los atletas en estos grupos. Demasiado, este contexto es generalmente marcado por la vulnerabilidad fĂsica
y emocional del deportista, y los acuerdos que hace dentro de este contexto se acompañan con dilemas morales, debido
a que tales adolescentes idealizan el entrenador como un arquetipo paterno.
la agresividad. Por lo tanto, este estudio tuvo como objetivo diagnosticar la existencia de relaciones homosexuales entre
adolescentes atletas de fĂștbol y sus entrenadores y la representaciĂłn simbĂłlica de estas relaciones. TambiĂ©n comprender
la intencionalidad de las relaciones homoafetivas que se intercambian entre algunos componentes del equipo directivo y(undefined
The Public Repository of Xenografts enables discovery and randomized phase II-like trials in mice
More than 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publicly available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment, called the Public Repository of Xenografts (PRoXe). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional, and proteomic biomarkers in both treatment-naive and relapsed/refractory disease
InfluĂȘncia de fatores ambientais na distribuição de famĂlias de insetos aquĂĄticos em rios no sul do Brasil
- âŠ