Dynamic critical exponents of the Ising model with multispin interactions

We revisit the short-time dynamics of 2D Ising model with three spin interactions in one direction and estimate the critical exponents $z,$ $\theta,$ $\beta$ and $\nu$. Taking properly into account the symmetry of the Hamiltonian we obtain results completely different from those obtained by Wang et al.. For the dynamic exponent $z$ our result coincides with that of the 4-state Potts model in two dimensions. In addition, results for the static exponents $\nu$ and $\beta$ agree with previous estimates obtained from finite size scaling combined with conformal invariance. Finally, for the new dynamic exponent $\theta$ we find a negative and close to zero value, a result also expected for the 4-state Potts model according to Okano et al.Comment: 12 pages, 9 figures, corrected Abstract mistypes, corrected equation on page 4 (Parameter Q

The nexus between port governance and performance

The diversity of port governance models in the world, sometimes even within the same country, has aroused the interest of researchers. This study is based on contingency theory to support the port governance model. The purpose is to understand the port governance model and the relation with port performance. There are three objectives: to analyze the port governance mechanisms; to analyze the port performance factors; and to understand the influence of the governance model mechanisms on port performance. A factorial analysis was used to determine the main components, and the methodology of the structural equation model was used to analyze a survey sample of 105 valid responses from specialists and managers of port user’s companies that operate in the main Portuguese ports. This study demonstrates that port governancemodel influences directly the port performance. The main contribution of this paper to the literature is providing a set of factors that public managers may decide when changing the characteristics of the port governance models to ensure their performance. It was also observed the approximation of the port expert vision of port governance with models described in literature.info:eu-repo/semantics/publishedVersio

Design of a Rotman lens operating in the full K/Ka band using ridge waveguide technology

Several services associated with satellite on the move and 5G applications are populating the K and Ka frequency bands. Beam forming networks are crucial components for achieving the necessary beam flexibility and agility of these systems. The Rotman lens is being widely investigate as a cost-effective solution for overcoming the main limitations of other types of beam forming networks, namely bandwidth, complexity, and size. One of the main design challenges is obtaining broadband transitions for the array and beam ports. In this work, we used a standard K/Ka double ridge (WRD180) for interfacing with the Rotman Lens. The main motivation for this choice is the wide bandwidth, compatible with the K/Ka satcom frequency bands, and the use of air/vacuum propagation medium in the parallel plate waveguide section to avoid dielectric losses associated with microstrip implementations. We present a design capable of fully exploiting the ridge waveguide bandwidth with wide beam scanning, outperforming previous works. The presented design consists of a 13×7 Rotman Lens with a scanning range of ±50 degrees operating between 16 and 40 GHz, validated through full-wave simulations.info:eu-repo/semantics/acceptedVersio

Identification of polymorphisms associated with production traits on chicken (Gallus gallus) chromosome 4.

Genetic selection for production traits has resulted in a rapid improvement in animal performance and development. Previous studies have mapped quantitative trait loci for body weight at 35 and 41 days, and drum and thigh yield, onto chicken chromosome 4. We investigated this region for single nucleotide polymorphisms and their associations with important economic traits. Three positional candidate genes were studied: KLF3 (Krüeppel-like factor 3), SLIT2 (Slit homolog 2), and PPARGC1A (peroxisome proliferator-activated receptor gamma, coactivator 1 alpha). Fragment sequencing of these genes was conducted in 11 F1 animals, and one polymorphism in each gene was selected and genotyped in an F2 population (N = 276) and a paternal broiler line TT (N = 840). Associations were identified with growth, carcass, and fat traits in the F2 and the paternal line (P < 0.05). Using single markers in both the F2 and the TT line, KLF3 was associated with weight gain (P < 0.05), PPPARGC1A was associated with liver and wing-parts weights and yields (P < 0.05), and SLIT2 was associated with back yield (P < 0.05) and fat traits (P < 0.05). Using multiple markers, KLF3 lost its significance in both populations, and SLIT2 was associated with feed conversion only in the TT population (P < 0.05). The QTLs mapped in the F2 population could be partly explained by PPARGC1A and SLIT2, which were associated with body weight at 35 and 41 days, respectively, and with drum and thigh yield in the same population. The results of this study indicate the importance of these genes for production traits

Reproductive activity of the shrimp Palaemon serratus Pennant, 1777 caught in Angeiras (northern Portugal)

The crustacean Decapoda Palaemon serratus Pennant, 1777 is abundant in Portugal (and is particularly important on the northern coast), where it is captured with a specific type of net called a sombreira. To obtain data on the reproductive biology of this commercially valuable species and its sustainable exploitation, samples of P. serratus were taken monthly to study its biometry and check for the presence of eggs in females. Our results indicate that 1) reproduction occurs between January and May; 2) the first maturity length is 74.6 mm (total length); and 3) there is a direct relationship between female size and spawning time, i.e., the smaller the female, the later her spawning.El crustáceo decápodo Palaemon serratus Pennant, 1777 es una especie abundante en Portugal, particularmente importante en la costa norte, cuya captura se efectúa mediante un tipo de red de malla llamada sombreira. Con el objetivo de obtener datos respecto a la biología reproductora de esta especie para su explotación sostenible, fueron efectuadas muestras mensuales de P. serratus para proceder a la biometría de los animales y comprobar la presencia de huevos en las hembras. Los resultados obtenidos permitieron determinar que la época de la reproducción es entre enero y mayo, que la talla de la primera madurez es de 74,6 mm de longitud total, y que existe una variación en la puesta durante la época reproductora íntimamente relacionada con la talla de las hembras, de tal forma que cuanto menor es el animal más tardía es su puesta.Instituto Español de Oceanografí

Competências de gestão: um instrumento de medida para a realidade portuguesa

Este estudo tem como objectivo descrever a construção de um instrumento de avaliação de competênciasde gestão baseado no CVF («Competing Values Framework»), de R. Quinn, recorrendo, como metodologia, à análise factorial confirmatória. O modelo conceptual identifica oito papéis desempenhados pelos gestores eficazes, reunindo cada papel três competências, perfazendo um total de 24 competências de gestão. Os oito papéis e as 24 competências integram quatro grandes modelos da literatura de gestão. A construção do instrumento teve por base umaamostra de 194 respondentes reflectindo um vasto leque de empresas, maioritariamente industriais, e uma diversidade de funções ao nível da gestão. Deste trabalho resultou a versão portuguesa de uma escala perceptiva de competências de gestão constituída por 48 itens, com boas propriedades métricas. Com este instrumento pensamos proporcionar aos investigadores um meio que cremos útil e válido na análise das competências de gestão em estudos organizacionais; e aos profissionais da gestão de pessoas um efectivo utensílio de análise e desenvolvimento de gestores eficazes adaptado à realidade portuguesa

Polymorphism in the FGFBP1 gene is associated with performance, carcass and meat quality traits in broilers.

Projeto/Plano de Ação: 01.06.10602-03

The heme-based oxygen sensor Rhizobium etli FixL: influence of auxiliary ligands on heme redox potential and implications on the enzyme activity

Conformational changes associated to sensing mechanisms of heme-based protein sensors are a key molecular event that seems to modulate not only the protein activity but also the potential of the Fe redox couple of the heme domain. In this work, midpoint potentials (E) assigned to the Fe redox couple of the heme domain of FixL from Rhizobium etli (ReFixL) in the unliganded and liganded states were determined by spectroelectrochemistry in the presence of inorganic mediators. In comparison to the unliganded ReFixL protein (+ 19 mV), the binding to ligands that switch off the kinase activity induces a negative shift, i. e. E = − 51, − 57 and − 156 mV for O, imidazole and CN, respectively. Upon binding to CO, which does not affect the kinase active, E was observed at + 21 mV. The potential values observed for Fe of the heme domain of ReFixL upon binding to CO and O do not follow the expected trend based on thermodynamics, assuming that positive potential shift would be expected for ligands that bind to and therefore stabilize the Fe state. Our results suggest that the conformational changes that switch off kinase activity upon O binding have knock-on effects to the local environment of the heme, such as solvent rearrangement, destabilize the Fe state and counterbalances the Fe-stabilizing influence of the O ligand