Light-front zero-mode contribution to the Ward Identity

In a covariant gauge we implicitly assume that the Green's function propagates information from one point of the space-time to another, so that the Green's function is responsible for the dynamics of the relativistic particle. In the light front form one would naively expect, that this feature would be preserved. In this manner, the fermionic field propagator can be split into a propagating piece and a non-propagating (contact) term. Since the latter (contact) one does not propagate information; and therefore, supposedly can be discarded with no harm to the field dynamics we wanted to know what would be the impact of dropping it off. To do that, we investigated its role in the Ward identity in the light front. Here we use the terminology Ward identity to identify the limiting case of photon's zero momentum transfer in the vertex from the more general Ward-Takahashi identity with nonzero momentum transfer.

Managing object identity with less I/O operations

Non-conventional database management systems are used to achieve a better performance when dealing with complex data. One fundamental concept of these systems is object identity (OID). Two techniques can be used for the implementation of OIDs: physical or logical. A logical implementation of OIDs, based on an Indirection Table, is used by NuGeM, a multimedia data manager kernel which is described in this paper. NuGeM Indirection Table allows the relocation of all pages in a database. The proposed strategy modifies the workings of this table so that it is possible to reduce considerably the number of I/O operations during the request and release of pages containing objects and their OIDs. Tests show a reduction of 84% in reading operations and a 67% reduction in writing operations when pages are requested. Although no changes were observed in writing operations during the release of pages, a 100% of reduction in reading operations was obtained. © 2012 IEEE.

Predation-risk effects of predator identity on the foraging behaviors of frugivorous bats

Predators directly and indirectly affect the density and the behavior of prey. These effects may potentially cascade down to lower trophic levels. In this study, we tested the effects of predator calls (playbacks of bird vocalizations: Tyto alba, Speotyto cunicularia, and Vanellus chilensis), predator visual stimuli (stuffed birds) and interactions of visual and auditory cues, on the behavior of frugivore phyllostomid bats in the field. In addition, we tested if the effects of predation risk cascade down to other trophic levels by measuring rates of seed dispersal of the tree Muntingia calabura. Using video recording, we found that bats significantly decreased the foraging frequency on trees when a visual cue of T. alba was present. However, no stimuli of potential predatory birds, including vocalization of T. alba, affected bat foraging frequency. There was a change in bat behavior during 7 min, but then their frequency of activity gradually increased. Consequently, the presence of T. alba decreased by up to ten times the rate of seed removal. These results indicate that risk sensitivity of frugivorous phyllostomid bats depends on predator identity and presence. Among the predators used in this study, only T. alba is an effective bat predator in the Neotropics. Sound stimuli of T. alba seem not to be a cue of predation risk, possibly because their vocalizations are used only for intraspecific communication. This study emphasizes the importance of evaluating different predator stimuli on the behavior of vertebrates, as well as the effects of these stimuli on trait-mediated trophic cascades. © 2013 Springer-Verlag Berlin Heidelberg.

O novo caipira: o olhar do eu e do outro

Pós-graduação em Linguística e Língua Portuguesa - FCLAR

Crenças sobre a língua inglesa: o antiamericanismo e sua relação com o processo de ensino - aprendizagem de professores em formação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The right to an identity: birth registration in Latin America and the Caribbean

A disturbing token of child and adolescent vulnerability in Latin America and the Caribbean is that so many are deprived of any legal identity by failure to report their birth. This bars them from exercising basic citizen rights and can hinder their access to productive employment, social benefits and the justice system and deny them recognition as full citizens and the right to well-being, capacity development and political participation.

Discrimination of complex visual stimuli in Cebus apella: identity matching with pictures

Do capuchin monkeys respond to photos as icons? Do they discriminate photos of capuchin monkeys' faces? Looking for answers to these questions we trained three capuchin monkeys in simple and conditional discrimination tasks and tested the discriminations when comparison stimuli were partially covered. Three capuchin monkeys experienced in simultaneous simple discrimination and IDMTS were trained with repeated shifts of simple discriminations (RSSD), with four simultaneous choices, and IDMTS (1 s delay, 4 choices) with pictures of known capuchins monkeys' faces. All monkeys did discriminate the pictures in both procedures. Performances in probes with partial masks with one fourth of the stimulus hidden were consistent with baseline level. Errors occurred when a picture similar to the correct one was available among the comparison stimuli, when the covered part was the most distinct, or when pictures displayed the same monkey. Capuchin monkeys do match pictures of capuchin monkeys' faces to the sample. The monkeys treated different pictures of the same monkey as equivalent, suggesting that they respond to the pictures as icons, although this was not true to pictures of other monkeys. Subsequent studies may bring more evidence that capuchin monkeys treat pictures as depictions of real scenes.

Educação bilíngue em território indígena Waiwai: aldeia Tawanã

É cada vez maior o número de nações indígenas que reivindicam o direito a uma educação própria, capaz de, por um lado, ajudá-las a encontrar soluções para os problemas advindos do contato com a sociedade nacional e de, por outro, assegurar-lhes o fortalecimento da identidade étnica. A educação bilíngue promove formas aditivas ou subtrativas de bilinguismo. Esses métodos são relativos e estão relacionados com os argumentos e os parâmetros de cada escola ou instituição. Este trabalho se propõe a descrever a forma de educação desenvolvida nas séries iniciais, em uma das aldeias waiwai, localizada nas Terras Indígenas Nhamundá-Mapuera, no Município de Oriximiná – Rio Mapuera – especificamente na aldeia Tawanã. O objetivo principal deste estudo é analisar como o educador indígena emprega suas ferramentas metodológicas na transmissão de conhecimentos etnoculturais, e se através do letramento desenvolve uma educação bilíngue nesta escola. Em referência a essa realidade, este trabalho constitui-se de pesquisa bibliográfica, embasada em leituras e análises de livros, artigos, dissertações e teses da área da linguística; pesquisa e análise do material adquirido em pesquisa de campo, coletado nas Terras Indígenas Nhamundá-Mapuera, em especial na escola da Aldeia Tawanã.

On the identity of Lepismium lineare and L. warmingianum (Cactaceae, Rhipsalidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

On the identity of two species of Proctophyllodidae (Acari: Astigmata: Analgoidea) described by Herbert F. Berla in Brazil, with a description of Lamellodectes gen. nov and a new species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The importance of sensing one's movement in the world for the sense of personal identity

Within philosophy and cognitive science, the focus in relation to the problem of personal identity has been almost exclusively on the brain. We submit that the resulting neglect of the body and of bodily movements in the world has been detrimental in understanding how organisms develop a sense of identity. We examine the importance of sensing one’s own movements for the development of a basic, nonconceptual sense of self. More specifically, we argue that the origin of the sense of self stems from the sensitivity to spontaneous movements. Based on this, the organism develops a sense of “I move” and, finally, a sense of “I can move”. Proprioception and kinesthesis are essential in this development. At the same time, we argue against the traditional dichotomy between so-called external and internal senses, agreeing with Gibson that perception of the self and of the environment invariably go together. We discuss a traditional distinction between two aspects of bodily self: the body sense and the body image. We suggest that they capture different aspects of the sense of self. We argue that especially the body sense is of great importance to our nonconceptual sense of self. Finally, we attempt to draw some consequences for research in cognitive science, specifically in the area of robotics, by examining a case of missing proprioception. We make a plea for robots to be equipped not just with external perceptual and motor abilities but also with a sense of proprioception. This, we submit, would constitute one further step towards understanding creatures acting in the world with a sense of themselves.

Double-objective economic statistical design of the VP T-2 control chart: Wald's identity approach

Research has shown that applying the T-2 control chart by using a variable parameters (VP) scheme yields rapid detection of out-of-control states. In this paper, the problem of economic statistical design of the VP T-2 control chart is considered as a double-objective minimization problem with the statistical objective being the adjusted average time to signal and the economic objective being expected cost per hour. We then find the Pareto-optimal designs in which the two objectives are met simultaneously by using a multi-objective genetic algorithm. Through an illustrative example, we show that relatively large benefits can be achieved by applying the VP scheme when compared with usual schemes, and in addition, the multi-objective approach provides the user with designs that are flexible and adaptive.

The identity of Hyla leucotaenia Burmeister, 1861 (Anura: Hylidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A formação inicial de professores de inglês como espaço para a (re)construção de identidades

Pós-graduação em Estudos Linguísticos - IBILCE