Pseudogap temperature as a Widom line in doped Mott insulators

The pseudogap refers to an enigmatic state of matter with unusual physical properties found below a characteristic temperature $T^*$ in hole-doped high-temperature superconductors. Determining $T^*$ is critical for understanding this state. Here we study the simplest model of correlated electron systems, the Hubbard model, with cluster dynamical mean-field theory to find out whether the pseudogap can occur solely because of strong coupling physics and short nonlocal correlations. We find that the pseudogap characteristic temperature $T^*$ is a sharp crossover between different dynamical regimes along a line of thermodynamic anomalies that appears above a first-order phase transition, the Widom line. The Widom line emanating from the critical endpoint of a first-order transition is thus the organizing principle for the pseudogap phase diagram of the cuprates. No additional broken symmetry is necessary to explain the phenomenon. Broken symmetry states appear in the pseudogap and not the other way around.Comment: 6 pages, 4 figures and supplementary information; published versio

Rendimento de carcaça de frangos de corte alimentados com dietas peletizadas contendo glicerina bruta.

maior parte das dietas para frangos de corte são peletizadas e a glicerina bruta além de ser um alimento energético é um melhorador de peletes, contudo não há informações sobre a interação entre a peletização e o uso de glicerina bruta em características de carcaça de frangos de corte. Assim objetivou-se avaliar o rendimento de carcaça de frangos de corte alimentados com rações fareladas ou peletizadas com a inclusão de níveis crescentes de glicerina bruta. O delineamento experimental utilizado foi em blocos (peso) casualizados com 8 tratamentos e 8 repetições de 25 aves por unidade experimental, de acordo com um arranjo fatorial 2x4 (2 processamentos X 4 níveis de glicerina bruta: 0, 4, 8 e 12%). Aos 43 dias de idade 3 aves de cada box foram abatidas para avaliação de rendimento de carcaça e de cortes. O processamento influenciou o peso de carcaça e de cortes, contudo não houve o mesmo efeito para o rendimento, exceto para asas. Quanto ao uso de glicerina bruta, os pesos das carcaças e dos cortes apresentaram comportamento quadrático enquanto a gordura mostrou comportamento linear decrescente. Entretanto, para rendimento só houve efeito quadrático para carcaça, com ponto de máxima em 3,79%, aumento linear para asa e redução linear para gordura. O processamento de ração não afeta as características de carcaça avaliadas. A glicerina bruta melhora o rendimento de carcaça e reduz a deposição de gordura. Most diets for broilers are pelleted and crude glycerin is a pellet enhancer, in addition to be an energy source. However, there is no information about the interaction between pelleting and the use of crude glycerin on carcass characteristics of broilers. Therefore, the objective of this study was to evaluate carcass yield of broilers fed with meal or pelleted diets with increasing levels of crude glycerin. The experimental design was in randomized complete blocks (weight) with 8 treatments and 8 replicates of 25 birds each, according to a 2x4 factorial arrangement (2 physical forms X 4 levels of crude glycerin: 0, 4, 8 and 12%). Three birds from each pen were slaughtered at 43 days of age to evaluate carcass yield and cuts. Physical form of diet influenced the weight of carcass and cuts, but there was not any effect on yield, except for wings. Regarding the use of crude glycerin, carcass and cuts weights showed quadratic behavior while fat showed a decreasing linear effect. Yield showed quadratic effect only for carcass, with a maximum point at 3.79%, linear increase in wing and linear reduction for fat. Feed processing does not affect carcass yield while crude glycerin improves carcass yield and reduces fat deposition

Superconductivity in the two-dimensional Hubbard model with cellular dynamical mean-field theory: a quantum impurity model analysis

Doping a Mott insulator gives rise to unconventional superconducting correlations. Here we address the interplay between d-wave superconductivity and Mott physics using the two-dimensional Hubbard model with cellular dynamical mean-field theory on a $2\times2$ plaquette. Our approach is to study superconducting correlations from the perspective of a cluster quantum impurity model embedded in a self-consistent bath. At the level of the cluster, we calculate the probabilities of the possible cluster electrons configurations. Upon condensation we find an increased probability that cluster electrons occupy a four-electron singlet configuration, enabling us to identify this type of short-range spin correlations as key to superconducting pairing. The increased probability of this four-electron singlet comes at the expense of a reduced probability of a four-electron triplet with no significant probability redistribution of fluctuations of charges. This allows us to establish that superconductivity at the level of the cluster primarily involves a reorganisation of short-range spin correlations rather than charge correlations. We gain information about the bath by studying the spectral weight of the hybridization function. Upon condensation, we find a transfer of spectral weight leading to the opening of a superconducting gap. We use these insights to interpret the signatures of superconducting correlations in the density of states of the system and in the zero-frequency spin susceptibility.Comment: 19 pages, 10 figures; accepted versio

Of virus and hunters, an interview with Frédéric Keck (versão em inglês)

Frédéric Keck is one of the main figures of the contemporary anthropology of biosecurity. He graduated in philosophy at the École Normale Supérieure in Paris and at the Université Lille-III, also in France. After an experience at the University of California, Berkeley, he migrated to anthropology under the influence of Paul Rabinow. In the field of intellectual history, he published several works on the development of French anthropology and its relationship with philosophy, exploring the ide..

Oncoplastic conservative surgery for breast cancer: long-term outcomes of our first ten years experience

The main goal of oncoplastic breast surgery (OBS) is to optimize cosmetic outcomes and reduce patient morbidity, while still providing an oncologically-safe surgical outcome and extending the target population of conservative surgery. Although the growing number of reported experiences with oncoplastic surgery, few studies account for the long-term outcomes