Spin configurations in hard-soft coupled bilayer systems: from rigid magnet to exchange spring transitions

We investigate equilibrium properties of an exchange-spring magnetic system constituted of a soft layer (e.g. Fe) of a given thickness on top of a hard magnetic layer (e.g. FePt). The magnetization profile M(z) as a function of the atomic position ranging from the bottom of the hard layer to the top of the soft layer is obtained in two cases with regard to the hard layer: i) in the case of a rigid interface (the FePt layer is a single layer), the profile is obtained analytically as the exact solution of a sine-Gordon equation with Cauchy's boundary conditions. Additional numerical simulations also confirm this result. Asymptotic expressions of M(z) show a linear behavior near the bottom and the top of the soft layer. In addition, a critical value of the number of atomic planes in the soft layer, that is necessary for the onset of spin deviations, is obtained in terms of the anisotropy and exchange coupling between the adjacent plane in the soft layer. ii) in the case of a relaxed interface (the FePt layer is a multilayer), the magnetization profile is obtained numerically for various Fe and FePt films thicknesses and applied field.Comment: 10 pages, 9 figures, PRB submitted (12-07-2010

Are fathers’ rearing histories associated with their involvement in childrearing? A Peruvian study

This study compares father involvement, relative to the mother, in a group of Peruvian families with preschool age children. We have also sought to understand if father’s rearing history and sociodemographic characteristics are predictors of his own involvement in child related activities. Two hundred and six families participated in the study. Results showed that mothers were more involved in direct and indirect care, and fathers tended to be more involved in play. Teaching/discipline and outdoor leisure activities were shared. The models tested for paternal involvement in direct, indirect care, and outdoor leisure were significant. Father´s rearing history was a main predictor of direct care and outdoor leisure. Fathers’ perceptions of their own mothers’ care were negatively associated with their involvement in direct care; and their perceptions of their own fathers’ overprotection/control were negatively associated with fathers’ involvement in outdoor leisure. Results are discussed based on stereotypical gender-based role division in childrearing, and the modeling and compensatory hypotheses.info:eu-repo/semantics/publishedVersio

ESTRATÉGIA DISCURSIVA DA REVISTA VEJA EM UM ARTIGO DE OPINIÃO SOBRE EDUCAÇÃO

Neste trabalho são apresentados dados de uma pesquisa, inserida no campo da Linguística Aplicada, cuja análise objetivou identificar a importância dos meios de comunicação na formação da opinião pública, nas decisões e nas concepções que circulam o mundo. Especificamente, a pesquisa buscou verificar a estratégia discursiva da Revista Veja, em um artigo de opinião, apontando os recursos argumentativos empregados pelo articulista. Utilizamos como corpus um artigo de opinião, escrito pelo colunista Cláudio Moura Castro, que aborda o papel do professor, em especial, sua remuneração, publicado em 27 de julho de 2016. Como suporte à análise do objeto, utilizamos os pressupostos teóricos acerca das concepções de dialogismo e ideologia bakhtinianos, a fim de desvelar concepções implícitas de linguagem e de ideologia no discurso midiático. Os resultados mostraram que as contradições e os conflitos são marcas do discurso jornalístico, que nos mobilizam a refletir até que ponto o que a mídia traz traduz a realidade. A análise dos dados mostrou que a Revista Veja estabelece com seu leitor imaginado uma relação paradoxal: por um lado, imagina-o como um leitor articulado, com bom nível de compreensão do mundo; por outro, imagina-o como um leitor ingênuo, cuja opinião deve ser construída pelos jornalistas. 

Adiabatic Formation of Rydberg Crystals with Chirped Laser Pulses

Ultracold atomic gases have been used extensively in recent years to realize textbook examples of condensed matter phenomena. Recently, phase transitions to ordered structures have been predicted for gases of highly excited, 'frozen' Rydberg atoms. Such Rydberg crystals are a model for dilute metallic solids with tunable lattice parameters, and provide access to a wide variety of fundamental phenomena. We investigate theoretically how such structures can be created in four distinct cold atomic systems, by using tailored laser-excitation in the presence of strong Rydberg-Rydberg interactions. We study in detail the experimental requirements and limitations for these systems, and characterize the basic properties of small crystalline Rydberg structures in one, two and three dimensions.Comment: 23 pages, 10 figures, MPIPKS-ITAMP Tandem Workshop, Cold Rydberg Gases and Ultracold Plasmas (CRYP10), Sept. 6-17, 201

Influence of Ovarian Follicle Sizes and Estrous Signs on Pregnancy Following Progesterone-Based Fixed Time Artificial Insemination in Water Buffaloes

The objectives of the present study were to elucidate the importance of follicle sizes and estrous signs during Controlled Internal Drug Release-Synch-human Chorionic Gonadotropin (CIDR-Synch-hCG) protocol for Fixed Time Artificial Insemination (FTAI) and to evaluate their association with pregnancy in water buffaloes. Data from riverine buffaloes (n = 207) under the CIDR-Synch-hCG protocol were analyzed. Buffaloes were administered with Gonadotropin-Releasing Hormone (GnRH) with insertion of CIDR on Day 0. Prostaglandin (PGF2α) was given on Day 7 with the removal of CIDR. hCG was given on Day 9, and AI was performed on Day 10. Follicle measurements by ultrasonography were done on Days 0, 7, and 10, and follicle sizes on those days were categorized into I, II, and III. Estrus signs were taken on the day of AI. The pregnancy diagnosis was done on Day 30-35 post-AI. The average size of follicles in Category III is significantly higher than those of Categories I and II, regardless of the Days of the protocol. Pregnancy is significantly (P<0.001) associated with Pre-Ovulatory Follicle (POF) size and uterine tonicity on the Day of AI but not with follicle sizes on Days 0 and 7, nor with mucus discharge discharge (P>0.05). The overall pregnancy rate is 44.44% while performing AI with POF size ≥12.0 mm increased the probability of pregnancy rate to 56.25%. In conclusion, the present study demonstrated a follicle size-based CIDR-Synch-hCG protocol providing new fertility indicators to improve FTAI efficiency in buffaloes with huge application in other livestock species

Modes of Oscillation in Radiofrequency Paul Traps

We examine the time-dependent dynamics of ion crystals in radiofrequency traps. The problem of stable trapping of general three-dimensional crystals is considered and the validity of the pseudopotential approximation is discussed. We derive analytically the micromotion amplitude of the ions, rigorously proving well-known experimental observations. We use a method of infinite determinants to find the modes which diagonalize the linearized time-dependent dynamical problem. This allows obtaining explicitly the ('Floquet-Lyapunov') transformation to coordinates of decoupled linear oscillators. We demonstrate the utility of the method by analyzing the modes of a small `peculiar' crystal in a linear Paul trap. The calculations can be readily generalized to multispecies ion crystals in general multipole traps, and time-dependent quantum wavefunctions of ion oscillations in such traps can be obtained.Comment: 24 pages, 3 figures, v2 adds citations and small correction

Ordered La0.7Sr0.3MnO3 nanohole arrays fabricated on a nanoporous alumina template by pulsed laser ablation

Highly ordered nanohole arrays of [Formula: see text] manganite have been synthesized using pulsed laser deposition on nanoporous alumina template. Their structure and phase formation were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD). The magnetic measurements were performed with respect to temperature and field and exhibit a ferromagnetic to paramagnetic transition at 284 K. In addition, the temperature dependence of electrical resistance was measured at different magnetic fields and an insulating phase throughout all the temperatures was observed. The low temperature ferromagnetic insulating state is discussed by the presence of a canted ferromagnetic state induced by the nanoholes. The present work shows the feasibility of combining both the nanoporous alumina template and pulsed laser ablation for the fabrication of perovskite manganite nanohole arrays which can also be extended to fabricate other multicomponent oxide nanohole materials.M K is thankful to FCT, Portugal for the Grant No. SFRH/ BPD/75110/2010. The authors acknowledged the financial supports from the projects NORTE-07–0124-FEDER000070, CERN/FIS-NUC/0004/2015 and IF/00686/2014

Fluoro-deoxi-glucose uptake and angiogenesis are independent biological features in lung metastases

Neoangiogenesis and enhanced glucose metabolism in neoplasms are likely to be activated by the same biochemical stimulus; hypoxia. A correlation between these two parameters has been postulated. The objective of this study was to evaluate the relationship between Fluoro-desoxi-glucose uptake at positron emission tomography scan and angiogenesis in lung metastasis. Fluoro-desoxi-glucose activity, expressed as a standard uptake value, and microvessel intratumoural density, were retrospectively calculated in a series of 43 lung metastasis resected in 19 patients. Primary sites were colorectal cancer in 16 metastases, sarcoma in eight, gynaecological in four and other sites in 15. The correlation between the two parameters was tested by logistic regression and multivariate analysis. Positron emission tomography scan was positive in 17 patients (sensitivity 89%). No correlation was observed between standard uptake value and microvessel intratumoural density in this series of lung metastasis. Positron emission tomography negative and positive nodules presented comparable value of microvessel intratumoural density (12.9 vs 11.3). Standard uptake value was significantly correlated with nodules size and was higher in colon cancer metastasis than in sarcoma ones. Microvessel intratumoural density was independent from nodule size but significantly higher in sarcoma than in colon cancer metastasis. The lack of correlation was confirmed by multivariate analysis after adjustment for tumour type and nodules size. The present study demonstrated that positron emission tomography scan is positive in a high proportion of patients regardless of microvessel density. Glucose uptake and angiogenesis appear to be independent biological features in lung metastasis. This observation may have implications for future antiangiogenic therapies