Frequency and power dependence of spin-current emission by spin pumping in a thin film YIG/Pt system

This paper presents the frequency dependence of the spin current emission in a hybrid ferrimagnetic insulator/normal metal system. The system is based on a ferrimagnetic insulating thin film of Yttrium Iron Garnet (YIG, 200 nm) grown by liquid-phase-epitaxy (LPE) coupled with a normal metal with a strong spin-orbit coupling (Pt, 15 nm). The YIG layer presents an isotropic behaviour of the magnetization in the plane, a small linewidth, and a roughness lower than 0.4 nm. Here we discuss how the voltage signal from the spin current detector depends on the frequency [0.6 - 7 GHz], the microwave power, Pin, [1 - 70 mW], and the in-plane static magnetic field. A strong enhancement of the spin current emission is observed at low frequencies, showing the appearance of non-linear phenomena.Comment: 7 pages, 5 figure

Calling All Students? Enrollment in Community-Engaged Learning Courses at a Marianist University

‘Community’ is a pervasive concept at the University of Dayton, a Catholic, Marianist institution in Dayton, Ohio. As such, it was unknown how students who enrolled in community engaged learning (CEL) courses were different from their peers in demographic characteristics, previous experiential learning, and views of community engagement. Findings can inform CEL recruitment as well as evaluation of CEL outcomes, especially at institutions with a similar values orientation. This mixed-methods study indicates that among four semesters of students in three selected CEL courses, few differences were found with students in non-CEL control groups. One significant difference found was in racial identity: fewer students with non-White racial identities enrolled in CEL courses than control groups. These findings illustrate the need for diversity and inclusion strategies to be applied to student recruitment for CEL courses

Tetragonal tungsten bronze compounds: relaxor vs mixed ferroelectric - dipole glass behavior

We demonstrate that recent experimental data (E. Castel et al J.Phys. Cond. Mat. {\bf 21} (2009), 452201) on tungsten bronze compound (TBC) Ba$_2$Pr$_x$Nd$_{1-x}$FeNb$_4$O$_{15}$ can be well explained in our model predicting a crossover from ferroelectric ($x=0$) to orientational (dipole) glass ($x=1$), rather then relaxor, behavior. We show, that since a "classical" perovskite relaxor like Pb(Mn$_{1/3}$ Nb$_{2/3}$)O$_3$ is never a ferroelectric, the presence of ferroelectric hysteresis loops in TBC shows that this substance actually transits from ferroelectric to orientational glass phase with $x$ growth. To describe the above crossover theoretically, we use the simple replica-symmetric solution for disordered Ising model.Comment: 5 two-column pages, 4 figure

Shell-Model Effective Operators for Muon Capture in ^{20}Ne

It has been proposed that the discrepancy between the partially-conserved axial-current prediction and the nuclear shell-model calculations of the ratio $C_P/C_A$ in the muon-capture reactions can be solved in the case of ^{28}Si by introducing effective transition operators. Recently there has been experimental interest in measuring the needed angular correlations also in ^{20}Ne. Inspired by this, we have performed a shell-model analysis employing effective transition operators in the shell-model formalism for the transition $^{20}Ne(0^+_{g.s.})+\mu^- \to ^{20}F(1^+; 1.057 MeV) + \nu_\mu$. Comparison of the calculated capture rates with existing data supports the use of effective transition operators. Based on our calculations, as soon as the experimental anisotropy data becomes available, the limits for the ratio $C_P/ C_A$ can be extracted.Comment: 9 pages, 3 figures include

Pros and Against of hormonal contraception

São reconhecidos diversos benefícios da contraceção hormonal em mulheres saudáveis: ciclos regulares, sem hemorragia abundante, sem dismenorreia e sem síndroma pré-menstrual. Mas a contraceção hormonal pode ser utilizada com objetivos terapêuticos específicos: tratamento da síndrome dos ovários poliquísticos, da endometriose, de diversos distúrbios hemorrágicos vaginais da mulher e, com as pílulas contracetivas que associam ao etinilestradiol um progestagénio com atividade antiandrogénica, terapêutica a longo prazo de acne, seborreia, hirsutismo e alopécia. Há ainda evidência científica de que a contraceção hormonal diminui o risco de aparecimento de quistos ou tumores nos ovários ou no endométrio.No entanto, a contraceção hormonal tem também os seus riscos. Sendo estes dependentes da dose, estima-se que nos contracetivos orais modernos, de baixa dosagem, eles sejam bastante menos frequentes e intensos do que nos primórdios da sua comercialização, mas não deixam de manifestar-se. Os mais frequentes estão associados a uma diminuição do bem-estar físico e/ou psicológico da mulher. Há também alguma evidência científica de que os contracetivos hormonais possam estar envolvidos no aparecimento/desenvolvimento de tumores hepáticos benignos, bem como no aumento do risco de litíase biliar. Contudo, os efeitos adversos mais graves são os efeitos cardiovasculares: aumento do risco de doença tromboembólica, aparecimento/agravamento de hipertensão arterial, dislipidémias e intolerância à glicose, e o consequente aumento do risco de doenças cardiovasculares. Por fim, a literatura refere que os contracetivos hormonais aumentam o risco de desenvolvimento de determinadas neoplasias, nomeadamente no colo do útero e na mama.Como em relação a qualquer medicamento, a relação benefício-risco terá sempre de ser tida em conta quando se prescreve contraceção hormonal, devendo o princípio da individualização terapêutica ter por base critérios científicos e clínicos mas também pessoais e socioeconómicos. Também no que se refere à contraceção se deve seguir a medicina baseada na evidência: usar toda a informação científica e disponibilizá-la à mulher para que ela, no contexto biopsicossocial em que se insere, possa tomar uma decisão informada no que se refere à sua fertilidade.Many benefits of the contraceptive pill are recognized in healthy women: regular cycles, without heavy bleeding, without dysmenorrhea and without premenstrual syndrome. But the contraceptive pill can be used for specific therapeutic objectives: treatment of polycystic ovaries, endometriosis, vaginal bleeding disorders and in long term acne, seborrhea, hirsutism and alopecia therapy (contraceptive pills containing ethinyl estradiol and a progestogen with antiandrogenic activity). There is still scientific evidence that the contraceptive pill reduces the risk of appearance of tumors or cysts in the ovary or endometrium.However the contraceptive pill also has its risks. These being dependent on the dose, it is estimated that in modern low-dose oral contraceptives, they are much less frequent and intense than in the early days of their marketing, but do not fail to manifest themselves. The most common are those that lead to a decrease in physical and / or psychological well-being of women. There is also some scientific evidence that hormonal contraceptives may be involved in the onset / development of benign liver tumors as well as increased risk of gallstones. But the most serious adverse effects are cardiovascular effects: increased risk of thromboembolic disease, onset / worsening of hypertension, dyslipidaemia and glucose intolerance, and the consequent increased risk of cardiovascular disease. Finally, the literature refers that hormonal contraceptives increase the risk of developing certain cancers, especially in the cervix and breast.As with any drug, the risk-benefit ratio must always be taken into account when prescribing one contraceptive pill, and the principle of therapeutic individualization should be based on scientific and clinical but also personal and socio-economic criteria. Also in regard to contraception we should follow evidence-based medicine: use all the scientific information and make it available to the woman so that she, in the biopsychosocial context in which it appears, can make an informed decision regarding her fertility

Topotecan-vincristine-doxorubicin in stage 4 high risk neuroblastoma patients failing to achieve a complete metastatic response to rapid COJEC : a SIOPEN study

Purpose : Metastatic response to induction therapy for high-risk neuroblastoma is a prognostic factor. In the International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) HR-NBL-1 protocol, only patients with metastatic complete response (CR) or partial response (PR) with <= three abnormal skeletal areas on iodine 123-metaiodobenzylguanidine ([I-123] mIBG) scintigraphy and no bone marrow disease proceed to high dose therapy (HDT). In this study, topotecan-vincristine-doxorubicin (TVD) was evaluated in patients failing to achieve these criteria, with the aim of improving the metastatic response rate. Materials and Methods : Patients with metastatic high-risk neuroblastoma who had not achieved the SIOPEN criteria for HDT after induction received two courses of topotecan 1.5 mg/m(2)/day for 5 days, followed by a 48-hour infusion of vincristine, 2 mg/m(2), and doxorubicin, 45 mg/m(2). Results : Sixty-three patients were eligible and evaluable. Following two courses of TVD, four (6.4%) patients had an overall CR, while 28 (44.4%) had a PR with a combined response rate of 50.8% (95% confidence interval [CI], 37.9 to 63.6). Of these, 23 patients achieved a metastatic CR or a PR with <= 3 mIBG skeletal areas and no bone marrow disease (36.5%; 95% CI, 24.7 to 49.6) and were eligible to receive HDT. Toxicity was mostly haematological, affecting 106 of the 126 courses (84.1%; 95% CI, 76.5 to 90.0), and dose reduction was necessary in six patients. Stomatitis was the second most common nonhematological toxicity, occurring in 20 patients (31.7%). Conclusion : TVD was effective in improving the response rate of high-risk neuroblastoma patients after induction with COJEC enabling them to proceed to HDT. However, the long-term benefits of TVD needs to be determined in randomized clinical trials

49Cr: Towards full spectroscopy up to 4 MeV

The nucleus 49Cr has been studied analysing gamma-gamma coincidences in the reaction 46Ti(alpha,n)49Cr at the bombarding energy of 12 MeV. The level scheme has been greatly extended at low excitation energy and several new lifetimes have been determined by means of the Doppler Shift Attenuation Method. Shell model calculations in the full pf configuration space reproduce well negative-parity levels. Satisfactory agreement is obtained for positive parity levels by extending the configuration space to include a nucleon-hole either in the 1d3/2 or in the 2s1/2 orbitals. A nearly one-to-one correspondence is found between experimental and theoretical levels up to an excitation energy of 4 MeV. Experimental data and shell model calculations are interpreted in terms of the Nilsson diagram and the particle-rotor model, showing the strongly coupled nature of the bands in this prolate nucleus. Nine values of K(pi) are proposed for the levels observed in this experiment. As a by-result it is shown that the values of the experimental magnetic moments in 1f7/2 nuclei are well reproduced without quenching the nucleon g-factors.Comment: 13 pages, 8 figure

The tumor suppressor PTEN and the PDK1 kinase regulate formation of the columnar neural epithelium

Epithelial morphogenesis and stability are essential for normal development and organ homeostasis. The mouse neural plate is a cuboidal epithelium that remodels into a columnar pseudostratified epithelium over the course of 24 hr. Here we show that the transition to a columnar epithelium fails in mutant embryos that lack the tumor suppressor PTEN, although proliferation, patterning and apical-basal polarity markers are normal in the mutants. The Pten phenotype is mimicked by constitutive activation of P13 kinase and is rescued by the removal of PDK1 (PDPK1), but does not depend on the downstream kinases AKT and mTORC1. High resolution imaging shows that PTEN is required for stabilization of planar cell packing in the neural plate and for the formation of stable apical-basal microtubule arrays. The data suggest that appropriate levels of membrane-associated PDPK1 are required for stabilization of apical junctions, which promotes cell elongation, during epithelial morphogenesis