On Aharonov-Casher bound states

In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the $\boldsymbol{\nabla}\cdot\mathbf{E}$ term cannot be neglected in the Hamiltonian if the spin of particle is considered. This term leads to the existence of a singular potential at the origin. By modeling the problem by boundary conditions at the origin which arises by the self-adjoint extension of the Hamiltonian, we derive for the first time an expression for the bound state energy of the Aharonov-Casher problem. As an application, we consider the Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the expression for the harmonic oscillator energies and compare it with the expression obtained in the case without singularity. At the end, an approach for determination of the self-adjoint extension parameter is given. In our approach, the parameter is obtained essentially in terms of physics of the problem.Comment: 11 pages, matches published versio

Relationship between polymorphism of growth hormone and precocity traits in Nellore heifers

Avaliaram-se as relações entre o polimorfismo do gene do hormônio do crescimento (GH) e as características de precocidade, em novilhas da raça Nelore. Amostras de sangue periférico foram obtidas de 181 animais de três rebanhos distintos do estado da Bahia, nas quais foi realizada a extração de DNA e a amplificação por PCR, seguidas por digestão com enzima de restrição AluI. Os fragmentos resultantes da digestão enzimática foram analisados em gel de agarose 2% para determinação dos respectivos genótipos. A frequência do alelo Leu nas amostras analisadas foi estimada em 100%. Em decorrência da alta incidência de homozigose para o alelo Leu, sugere-se que o restriction fragment lenght polymorphism AluI do gene GH não possa ser considerado como marcador molecular para precocidade sexual em novilhas Nelore nesses rebanhos.The relationships between polymorphism of growth hormone gene (GH) and precocity traits in Nellore heifers were evaluated. A total of 181 animals from three different farms of Bahia state, Brazil, were blood sampled. The DNA of each animal was extracted, amplified by PCR, and digested by "AluI" restriction enzyme, and the resultant fragments were analyzed in 2% agarose gel for genotype identification. The frequency of Leu allele in the analyzed samples was estimated in 100%. Due to the high incidence of homozygose for the Leu allele, it is suggested that the restriction fragment lenght polymorphism AluI of GH gene can not be considered as a molecular marker for sexual precocity in Nellore heifers of those herds.Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Modelling the electric field applied to a tokamak

The vector potential for the Ohmic heating coil system of a tokamak is obtained in semi-analytical form. Comparison is made to the potential of a simple, finite solenoid. In the quasi-static limit, the time rate of change of the potential determines the induced electromotive force through the Maxwell-Lodge effect. Discussion of the gauge constraint is included.Comment: 13 pages, 7 figures, final versio

Genetic mapping and QTLs detection in a Theobroma grandiflora progeny : S04P01

The genus Theobroma covers 22 native species to the Amazon region. Two species are cultivated in Brazil:Theobroma cacao and T. grandiflorum (cupuaçu). T. grandiflora is economically important to the amazonian states of Brazil where it was developed in food and cosmetics with various products manufactured mainly from the pulp of the seed. Both species are susceptible to Moniliophthora perniciosa (Stahel) Singer, the causal agent of witches' brooms disease. 139 SSRs markers (Single Sequence Repeat) from T. grandiflora and 500 SSRs developed by CIRAD in T. cacao, were used to select polymorphic markers and carry out a genetic mapping of a Th. Grandiflora progeny from "174" x "1074" clones, respectively resistant and susceptible to witches' brooms. 145 plants were obtained by Embrapa-CPATU (Belém) today installed in the field at the CEPLAC (Belém) station. Inoculations with the M. perniciosa (from T. grandiflora) were carried out in the progenies and parents to evaluate the resistance. Other observations as vigor or number of ovules per ovary were observed also. We present the first results obtained with the selection of polymorphic specific markers of Th Grandiflora and Cocoa and the first genotying results from 44 SSRs of T. grandiflora including 14 SSRs from expression sequences. In conclusion this study including different teams is ongoing to have at the end of the project: i) the first genetic map of Theobroma grandiflora, ii) identification of QTLs of resistance to witches' broom, and other QTLs and iii) to compare genetic map and QTLs between both species. (Texte intégral

New bounds for Tsallis parameter in a noncommutative phase-space entropic gravity and nonextensive Friedmann equations

In this paper, we have analyzed the nonextensive Tsallis statistical mechanics in the light of Verlinde's formalism. We have obtained, with the aid of a noncommutative phase-space entropic gravity, a new bound for Tsallis nonextensive (NE) parameter (TNP) that is clearly different from the ones present in the current literature. We derived the Friedmann equations in a NE scenario. We also obtained here a relation between the gravitational constant and the TNP.Comment: 15 pages. Final version to appear in Physica

Random Time-Dependent Quantum Walks

We consider the discrete time unitary dynamics given by a quantum walk on the lattice $\Z^d$ performed by a quantum particle with internal degree of freedom, called coin state, according to the following iterated rule: a unitary update of the coin state takes place, followed by a shift on the lattice, conditioned on the coin state of the particle. We study the large time behavior of the quantum mechanical probability distribution of the position observable in $\Z^d$ when the sequence of unitary updates is given by an i.i.d. sequence of random matrices. When averaged over the randomness, this distribution is shown to display a drift proportional to the time and its centered counterpart is shown to display a diffusive behavior with a diffusion matrix we compute. A moderate deviation principle is also proven to hold for the averaged distribution and the limit of the suitably rescaled corresponding characteristic function is shown to satisfy a diffusion equation. A generalization to unitary updates distributed according to a Markov process is also provided. An example of i.i.d. random updates for which the analysis of the distribution can be performed without averaging is worked out. The distribution also displays a deterministic drift proportional to time and its centered counterpart gives rise to a random diffusion matrix whose law we compute. A large deviation principle is shown to hold for this example. We finally show that, in general, the expectation of the random diffusion matrix equals the diffusion matrix of the averaged distribution.Comment: Typos and minor errors corrected. To appear In Communications in Mathematical Physic

Correlated Markov Quantum Walks

We consider the discrete time unitary dynamics given by a quantum walk on $\Z^d$ performed by a particle with internal degree of freedom, called coin state, according to the following iterated rule: a unitary update of the coin state takes place, followed by a shift on the lattice, conditioned on the coin state of the particle. We study the large time behavior of the quantum mechanical probability distribution of the position observable in $\Z^d$ for random updates of the coin states of the following form. The random sequences of unitary updates are given by a site dependent function of a Markov chain in time, with the following properties: on each site, they share the same stationnary Markovian distribution and, for each fixed time, they form a deterministic periodic pattern on the lattice. We prove a Feynman-Kac formula to express the characteristic function of the averaged distribution over the randomness at time $n$ in terms of the nth power of an operator $M$. By analyzing the spectrum of $M$, we show that this distribution posesses a drift proportional to the time and its centered counterpart displays a diffusive behavior with a diffusion matrix we compute. Moderate and large deviations principles are also proven to hold for the averaged distribution and the limit of the suitably rescaled corresponding characteristic function is shown to satisfy a diffusion equation. An example of random updates for which the analysis of the distribution can be performed without averaging is worked out. The random distribution displays a deterministic drift proportional to time and its centered counterpart gives rise to a random diffusion matrix whose law we compute. We complete the picture by presenting an uncorrelated example.Comment: 37 pages. arXiv admin note: substantial text overlap with arXiv:1010.400

Designing and evaluating a behaviour change intervention that introduces modification of time perceptions as a solution to promote sustainable behaviours

This research presents the design and evaluation of an intervention that introduces modification of time perceptions as one of the solutions to promote sustainable behaviours. It is demonstrated in this thesis that unnecessary energy use is often caused by temporal tensions, defined as the relation between actions to be performed and available time. This research proposes that it is possible to deliberately reduce temporal tensions, and this can motivate people to behave more sustainably. Persuasive technology and human-computer interaction provided the tools needed to manipulate time perceptions and therefore bring about changes in the specific behaviours that result in unnecessary energy usage. Previous studies indicate that behaviours play an important role in energy consumption. From the different domains of energy use that could be examined, cooking was chosen to be the platform where the studies on behaviour change and energy use would take place. How behaviours influence energy use motivated the design of empirical studies to understand behaviours related to domestic energy use and identify what are the determinants of these behaviours. Each determinant was related to a strategy to be included on a behaviour change intervention. A wider survey was developed to understand students acceptance of a set of proposed energy saving techniques, and resulted in a vast volume of information about user preferences and intentions to perform the suggested energy saving behaviours for cooking. It emerged that participants rushed into the cooking tasks without much deliberation, consequently not following preparation procedures and thus using more energy. Information gathered during the first studies also showed that participants behaviours were partially motivated by the need to speed up the cooking process in order to reduce boredom when they were waiting for the food to cook, consequently resulting in extra energy usage. The knowledge gathered from the preceding steps and a literature review informed the design of strategies to modify the non-sustainable behaviours and promote energy saving. A user-centred design process involving an idea generation session and scenario analysis was used to provide a set of strategies to be embedded in an intervention, containing the specific methods to tackle the correspondent determinants of behaviours. The specific needs of the cooking activity indicated that an electronic intervention was an adequate platform to be implemented and tested. Two high resolution working prototypes of the electronic interventions were developed as mobile phone applications. The final study comprised the evaluation of the proposed interventions in improving aspects of the cooking activity, the acceptance of the interventions and effectiveness in promoting energy saving

Recurrent duplications of the annexin A1 gene (ANXA1) in autism spectrum disorders

Validating the potential pathogenicity of copy number variants (CNVs) identified in genome-wide studies of autism spectrum disorders (ASD) requires detailed assessment of case/control frequencies, inheritance patterns, clinical correlations, and functional impact. Here, we characterize a small recurrent duplication in the annexin A1 (ANXA1) gene, identified by the Autism Genome Project (AGP) study