The K-process on a tree as a scaling limit of the GREM-like trap model

We introduce trap models on a finite volume $k$-level tree as a class of Markov jump processes with state space the leaves of that tree. They serve to describe the GREM-like trap model of Sasaki and Nemoto. Under suitable conditions on the parameters of the trap model, we establish its infinite volume limit, given by what we call a $K$-process in an infinite $k$-level tree. From this we deduce that the $K$-process also is the scaling limit of the GREM-like trap model on extreme time scales under a fine tuning assumption on the volumes.Comment: Published in at http://dx.doi.org/10.1214/13-AAP937 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

On the existence of supergravity duals to D1--D5 CFT states

We define a metric operator in the 1/2-BPS sector of the D1-D5 CFT, the eigenstates of which have a good semi-classical supergravity dual; the non-eigenstates cannot be mapped to semi-classical gravity duals. We also analyse how the data defining a CFT state manifests itself in the gravity side, and show that it is arranged into a set of multipoles. Interestingly, we find that quantum mechanical interference in the CFT can have observable manifestations in the semi-classical gravity dual. We also point out that the multipoles associated to the normal statistical ensemble fluctuate wildly, indicating that the mixed thermal state should not be associated to a semi-classical geometry.Comment: 22 pages, 2 figures. v2 : references added, typos correcte

Bosonic Field Propagators on Algebraic Curves

In this paper we investigate massless scalar field theory on non-degenerate algebraic curves. The propagator is written in terms of the parameters appearing in the polynomial defining the curve. This provides an alternative to the language of theta functions. The main result is a derivation of the third kind differential normalized in such a way that its periods around the homology cycles are purely imaginary. All the physical correlation functions of the scalar fields can be expressed in terms of this object. This paper contains a detailed analysis of the techniques necessary to study field theories on algebraic curves. A simple expression of the scalar field propagator is found in a particular case in which the algebraic curves have $Z_n$ internal symmetry and one of the fields is located at a branch point.Comment: 26 pages, TeX + harvma

Evidence of vertical transmission of Senecavirus A in naturally infected sows.

Abstract: Senecavirus A (SVA) is a Picornaviridae RNA virus that causes vesicular disease (VD) and transitory neonatal losses in pigs. The major ways SVA is spread are by oral, nasal, and feces. Vertical transmission of SVA was investigated during a VD epidemic in a farrow-to-finish herd in Brazil. Vesicular lesions were observed on sows before farrowing and on piglets within 24 h of birth. Analyses included RT-qPCR, viral isolation, sequencing, and virus-neutralization assays on serum, vesicular fluid, colostrum, and milk. Five out of ten sows were viremic before farrowing, and 46.7% of tested piglets had high viral loads in the first 24 h after birth. Infectious virus was detected in colostrum and milk from one postnatal sow. Despite high levels of neutralizing antibodies (nAbs) in piglet serum, colostrum, and milk, piglets were not protected from viremia and clinical illness. These findings support the vertical and congenital transmission of SVA

Barragem subterrânea: uma alternativa sustentável para a agricultura familiar no semi-árido brasileiro.

Este trabalho foi desenvolvido com o objetivo de caracterizar as condições estruturais e a diversificação de cultivos em vinte e uma Barragens subterrâneas (BS?s) e a produção em sete barragens, monitoradas no ano de 2006, em oito cidades dos estados de Pernambuco e Bahia. Os resultados demonstram que a estrutura da maioria das BS?s está em boas condições, e foi observado também o interesse dos agricultores por outros cultivos, estimulando um redesenho dos agroecossistemas, e o aprofundamento das interações do sistema, criando ambientes mais diversificados biologicamente e mais sustentáveis. Os resultados demonstraram que a diversidade de espécies frutíferas (41%) é maior que as outras espécies nas barragens estudadas, seguida das forragens (23%) e das oleráceas (14%). As culturas de subsistência e outros tipos de cultivos (plantas medicinais, corantes, entre outras) possuem menor diversidade (11%). Em relação à produção, a atividade que tem maior retorno é a forragicultura, seguida das culturas de subsistência. O material forrageiro é usado na produção de feno e silagem. Estes resultados refletem o interesse econômico da agricultura familiar do semi-árido destes dois estados que é baseada, principalmente, na caprino-ovinocultura.Edição dos Resumos do V Congresso Brasileiro de Agroecologia, Guarapari, out. 2007

An example of localized D-branes solution on PP-wave backgrounds

In this note we provide an explicit example of type IIB supersymmetric D3-branes solution on a pp-wave like background, consisting in the product of an eight-dimensional pp-wave times a two-dimensional flat space. An interesting property of our solution is the fully localization of the D3-branes (i.e. the solution depends on all the transverse coordinates). Then we show the generalization to other Dp-branes and to the D1/D5 system.Comment: 14 pages, 1 table; v2. references adde

Avaliação de espécies vegetais para cobertura do solo em sistemas irrigados de cultivo orgânico de manga no Pólo Petrolina, BA/Juazeiro, BA.

No Pólo Petrolina, PE/Juazeiro, BA, região semiárida do Nordeste brasileiro, muitos agricultores adotam no manejo do solo espécies vegetais plantadas em conjunto (misturadas) para produção de material orgânico. Essa mistura é conhecida como coquetel vegetal. Neste sentido, o presente estudo se propôs avaliar espécies vegetais para cobertura do solo em sistemas irrigados de cultivo orgânico de manga no Pólo Petrolina, BA/Juazeior,BA., de forma a favorecer o aumento da biodiversidade e fornecer material orgânico nos agroecossistemas propiciando o aumento de sua sustentabilidade. Para atingir os objetivos propostos avaliaram-se a produção de fitomassa, os teores de macro e micronutrientes na parte aérea e a atividade microbiana do solo. Com base nos resultados obtidos, a melhor opção de coquetel vegetal, nas condições de clima e solos estudados, foi o tratamento 4 (T4 - 50% leguminosa e 50% não leguminosa), seguido do T3 (75% leguminosa e 25% não leguminosa) e T5 (25% leguminosa e 75% não leguminosa)

Gate-tunable bandgap in bilayer graphene

The tight-binding model of bilayer graphene is used to find the gap between the conduction and valence bands, as a function of both the gate voltage and as the doping by donors or acceptors. The total Hartree energy is minimized and the equation for the gap is obtained. This equation for the ratio of the gap to the chemical potential is determined only by the screening constant. Thus the gap is strictly proportional to the gate voltage or the carrier concentration in the absence of donors or acceptors. In the opposite case, where the donors or acceptors are present, the gap demonstrates the asymmetrical behavior on the electron and hole sides of the gate bias. A comparison with experimental data obtained by Kuzmenko et al demonstrates the good agreement.Comment: 6 pages, 5 figure