Fluctuations in a superconducting quantum critical point of multi-band metals

In multi-band metals quasi-particles arising from different atomic orbitals coexist at a common Fermi surface. Superconductivity in these materials may appear due to interactions within a band (intra-band) or among the distinct metallic bands (inter-band). Here we consider the suppression of superconductivity in the intra-band case due to hybridization. The fluctuations at the superconducting quantum critical point (SQCP) are obtained calculating the response of the system to a fictitious space and time dependent field, which couples to the superconducting order parameter. The appearance of superconductivity is related to the divergence of a generalized susceptibility. For a single band superconductor this coincides with the \textit{Thouless criterion}. For fixed chemical potential and large hybridization, the superconducting state has many features in common with breached pair superconductivity with unpaired electrons at the Fermi surface. The T=0 phase transition from the superconductor to the normal state is in the universality class of the density-driven Bose-Einstein condensation. For fixed number of particles and in the strong coupling limit, the system still has an instability to the normal sate with increasing hybridization.Comment: 10 pages, 8 figure

Fishers' Knowledge About Fish Trophic Interactions In The Southeastern Brazilian Coast

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background: Data derived from studies of fishers' local ecological knowledge (LEK) can be invaluable to the proposal of new studies and more appropriate management strategies. This study analyzed the fisher's LEK about trophic relationships of fishes in the southeastern Brazilian coast, comparing fishers' LEK with scientific knowledge to provide new hypotheses. Methods: The initial contacts with fishers were made through informal visits in their residences, to explain the research goals, meet fishers and their families, check the number of resident fishers and ask for fishers' consent to participate in the research. After this initial contact, fishers were selected to be included in the interviews through the technique of snowball sampling. The fishers indicated by others who attended the criteria to be included in the research were interviewed by using a semi-structured standard questionnaire. Results: There were interviewed 26 artisanal fishers from three communities of the Ilhabela: Jabaquara, Fome and Serraria. The interviewed fishers showed a detailed knowledge about the trophic interactions of the studied coastal fishes, as fishers mentioned 17 food items for these fishes and six fish and three mammals as fish predators. The most mentioned food items were small fish, shrimps and crabs, while the most mentioned predators were large reef fishes. Fishers also mentioned some predators, such as sea otters, that have not been reported by the biological literature and are poorly known. Conclusions: The LEK of the studied fishers showed a high degree of concordance with the scientific literature regarding fish diet. This study evidenced the value of fishers' LEK to improve fisheries research and management, as well as the needy to increase the collaboration among managers, biologists and fishers.11Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [04/02183-6]FAPESP [01/05263-2, 2012/16722-2

Percepción del estrés competitivo y cultura en futbolistas profesionales de Brasil y Portugal

The main purpose of this study was to compare how soccer players with different cultural backgrounds and a similar level of experience perceive the concept of stress. 18 Brazilian soccer players from the Brazilian National Team and 20 Portuguese players from the Portuguese National Team with mean of age 26.69 +- 4.1 and 26.05 +- 2.3 years were assessed using a Stress in Football Inventory. One trend was very clear. When items were assessed as being positive by both groups,the Brazilians tended to rate them in a significantly more positive way. Likewise, when items were negatively assessed by both groups, the Brazilians tended to assess them more negatively. What was perhaps most interesting was the high number of items that were assessed as having a totally opposite effect, with what was perceived by the Brazilians to be negative being seen as neutral or positive by the Portuguese. Cultural factors very probably explain the variance in perceptions of stress

Quantum criticality in inter-band superconductors

In fermionic systems with different types of quasi-particles, attractive interactions can give rise to exotic superconducting states, as pair density wave (PDW) superconductivity and breached pairing. In the last years the search for these new types of ground states in cold atom and in metallic systems has been intense. In the case of metals the different quasi-particles may be the up and down spin bands in an external magnetic field or bands arising from distinct atomic orbitals that coexist at a common Fermi surface. These systems present a complex phase diagram as a function of the difference between the Fermi wave-vectors of the different bands. This can be controlled by external means, varying the density in the two-component cold atom system or, in a metal, by applying an external magnetic field or pressure. Here we study the zero temperature instability of the normal system as the Fermi wave-vectors mismatch of the quasi-particles (bands) is reduced and find a second order quantum phase transition to a PDW superconducting state. From the nature of the quantum critical fluctuations close to the superconducting quantum critical point (SQCP), we obtain its dynamic critical exponent. It turns out to be $z=2$ and this allows to fully characterize the SQCP for dimensions $d \ge 2$.Comment: 5 pages, 1 figur

Caracterização morfológica de exemplares de equinos da raça quarto de milha utilizadas no laço comprido.

Objetivou-se realizar a caracterização morfológica de exemplares de equinos da raça Quarto de Milha utilizados no Laço Comprido. Foram amostrados 69 equinos (54 fêmeas e 15 machos) com idade adulta, utilizados em provas realizadas em Miranda e São José do Camisão - Aquidauana, sub-regiões do Pantanal do MS. Com auxílio de fita métrica, mensuraram-se: perímetros: torácico, canela, joelho e antebraço; largura: peito, garupa, cabeça e ísquio; tamanho: orelha; alturas: cernelha, codilho ao solo, garupa, joelho e dorso lombar; comprimentos: quartela torácica, perna, canela pélvica, canela torácica, garupa, pescoço, cabeça, corporal, espádua, dorso e antebraço; longitude: rosto; distâncias: escápula boleto e tórax abdômen. Com base nas medidas, estimaram-se os índices de conformação: relação cernelha garupa, corporal, dáctilo torácico, peso e carga na canela. O estudo da variação das pelagens baseou-se a partir da simples contagem das ocorrências do fenômeno, entre os eqüinos. Analisou-se possível efeito do dimorfismo sexual sobre as características morfométricas e conformação. Para interpretação das pelagens, a análise estatística foi realizada em função da distribuição de freqüências. Não houve diferenças significativas (P<0,05) em nenhuma das características entre machos e fêmeas. Os eqüinos foram classificados como cavalos de médio porte, aptidões intermediárias para força e velocidade, com bom equilíbrio entre os membros locomotores, aptidões intermediárias para uso em sela ou tração e com boa capacidade dos membros locomotores deslocarem toda a massa corporal. Observou maior predominância da pelagem alazã (52,17%), seguida da castanha (18,84%) e baia (8,69%), ao passo que as pelagens lobuna (1,44%), zaina (4,34%) obtiveram menor representabilidade

Fishers’ knowledge about fish trophic interactions in the southeastern Brazilian coast

Data derived from studies of fishers' local ecological knowledge (LEK) can be invaluable to the proposal of new studies and more appropriate management strategies. This study analyzed the fisher's LEK about trophic relationships of fishes in the southeastern Brazilian coast, comparing fishers' LEK with scientific knowledge to provide new hypotheses. The initial contacts with fishers were made through informal visits in their residences, to explain the research goals, meet fishers and their families, check the number of resident fishers and ask for fishers' consent to participate in the research. After this initial contact, fishers were selected to be included in the interviews through the technique of snowball sampling. The fishers indicated by others who attended the criteria to be included in the research were interviewed by using a semi-structured standard questionnaire. There were interviewed 26 artisanal fishers from three communities of the Ilhabela: Jabaquara, Fome and Serraria. The interviewed fishers showed a detailed knowledge about the trophic interactions of the studied coastal fishes, as fishers mentioned 17 food items for these fishes and six fish and three mammals as fish predators. The most mentioned food items were small fish, shrimps and crabs, while the most mentioned predators were large reef fishes. Fishers also mentioned some predators, such as sea otters, that have not been reported by the biological literature and are poorly known. The LEK of the studied fishers showed a high degree of concordance with the scientific literature regarding fish diet. This study evidenced the value of fishers' LEK to improve fisheries research and management, as well as the needy to increase the collaboration among managers, biologists and fishers

Medidas angulares de equinos da raça quarto de milha utilizados em provas de laço comprido.

Caracterizaram-se as medidas angulares de equinos Quarto de Milha utilizados em duas etapas (município de Miranda e distrito de Camisão) de Laço Comprido em sub-regiões do Pantanal/MS. Amostraram-se 54 equinos (42 fêmeas e 12 machos) Quarto de Milha, com idade adulta e peso corporal estimado em 543,17± 81,02 kg. Com auxílio de goniômetro aferiram-se as seguintes medidas angulares: ângulo de cabeça (ACAB), ângulo de pescoço (APE), ângulo escápulo-umeral (AEU), ângulo escápulo solo (AES), ângulo úmero-radial (AUR), ângulo radial-carpo-metacarpiano (ARCM), ângulo metacarpo-falangeano- (AMF), ângulo coxo-solo (ACS), ângulo coxo-femoral (ACF), ângulo fêmur-tibial (AFT), ângulo tíbio-tarso-metatarsiano (ATTM) e ângulo metatarso-falangeano (AMFa). Realizou-se análise de variância entre as medidas angulares considerando o dimorfismo sexual como efeito fixo; e análise multivariada para redução de váriaveis passiveis de serem mantidas por apresentarem maior contribuição para variação total. Verificou-se diferença significativa (P<0,05) por dimorfismo sexual apenas em ACAB e A RCM. Maiores coeficientes de variação (CV) foram observados para em ACF (27,37%) e ACS (17,59%), ao passo que ARCM (2,05%) e ATTM (3,12%) apresentaram mais uniforme entre os equinos machos e fêmeas. Os seis primeiros componentes principais apresentaram percentagem de variância acumulada de 75,64% da variação total. Sete variáveis que apresentaram maiores coeficientes de ponderação, em valor absoluto, a partir do último componente principal em direção ao primeiro, foram descartadas. As variáveis sugeridas para descarte foram, respectivamente, em ordem de menor importância para a explicação da variação total: APE, ACF, ACS, AUR, AEU e ACAB, pois apresentam associação aos componentes que explicam muito pouco a variabilidade dos dados

{\beta}-YbAlB4: a critical nodal metal

We propose a model for the intrinsic quantum criticality of {\beta}-YbAlB4, in which a vortex in momentum space gives rise to a new type of Fermi surface singularity. The unquenched angular momentum of the |J = 7/2,m_J = \pm5/2> Yb 4f-states generates a momentum-space line defect in the hybridization between 4f and conduction electrons, leading to a quasi-two dimensional Fermi surface with a k\perp4 dispersion and a singular density of states proportional to E^{-1/2}. We discuss the implications of this line-node in momentum space for our current understanding of quantum criticality and its interplay with topology

Are biological species and higher-ranking categories real? Fish folk taxonomy on Brazil’s Atlantic Forest coast and in the Amazon

Analysis of Brazilian fishers' classifications of 24 marine (Atlantic coast) and 24 freshwater (Amazon) fish species reveals that fishers from the Atlantic coast identify fish mainly through generic names (primary lexemes), while riverine Amazonian fishers typically identify them through binomials. The similarity of Amazonian fish species seems to contribute to the detailed folk taxonomy used by riverine fishers. High-ranking groups called "relatives" or "cousins" are sorted by fishers in terms of similarities of habitat, diet, and morphology and, secondarily, behavior. The general correspondence between the folk and scientific taxonomies reinforces the reality of both the supracategories used by these fishers and the biological groups as discontinuities in nature. Given the urgency of biological inventories and the lack of knowledge of high-biodiversity environments such as the Atlantic Forest and the Amazon, these results suggest that fisher knowledge and experience could contribute to scientific research.49229130

ARTISANAL FISHING AND FISHERMEN OF ILHABELA - SAO PAULO STATE - BRAZIL

This work was developed in Ilhabela, northern coast of the state of Sao Paulo, Brazil. The objective was to characterize artisanal fisheries in fishing communities of Jabaquara Beach, Serraria Beach, Fome Beach and Bonete Beach. Fishing methods, strategies and equipment used by fishers, as well as, local forms of marketing and exploited fishery resources are approached in this study. The data were collected through interviews using semi-structured questionnaires. Information such as general aspects of fishing, socioeconomic data, time of fishing technology and fishing strategies in use was obtained. This research included 20 fishermen from Serraria beach, six from Jabaquara beach, 10 from Fome beach and 18 from Bonete Beach, totaling 54 interviews. In general, the artisanal fishery is still the main economic activity; however, develop other activities, such as activities related to tourism. Forty five fishing points were cited. The main gear used by fishers in the fishing points, along with fishing techniques are the rede de espera (set gillnet) and the main type of vessel is the batera. The ichthyofauna was characterized with 76 identified species belonging to 65 genera and 38 biological families. The aspects related to fishing activities are part of the knowledge of fishermen on the environment and constitute a comprehensive collection of information that, together with biological information can be useful to deepen the knowledge of fish ecology and management of local fisheries resources. The information available from this study is important as a baseline to allow temporal comparison of the fishing and fish in this region.38323124