Non-resonant leptogenesis in seesaw models with an almost conserved B-L

We review the motivations and some results on leptogenesis in seesaw models with an almost conserved lepton number. The paper is based on a talk given at the 5th International Symposium on Symmetries in Subatomic Physics, SSP2012.Comment: 8 pages, 1 figure. Published in the proceedings of the 5th International Symposium on Symmetries in Subatomic Physics, SSP201

Terapia Celular para o Tratamento de Cardiopatias Isquêmicas: Desenvolvimento de um Protocolo Pré-clinico

RESUMEN Apesar dos avanços clínicos, cirúrgicos e farmacológicos, quando a doença cardíaca isquêmica é muita avançada e difusa, os métodos atualmente disponíveis não são totalmente efetivos para evitar a perda de cardiomiócitos funcionais. Isso acarretará alterações na geometria ventricular (remodelamento), com perda progressiva da função ventricular e desenvolvimento de insuficiencia cardíaca. Recentes avanços na compreensão da biologia das células-tronco reinstalaram o conceito de transplante celular para substituir células não funcionais. A regeneração do miocárdio tem despertado um crescente interesse visando atender este propósito. A proposta deste trabalho é o de desenvolver um protocolo pré-clínico seguro e eficiente que possa contribuir para uma melhor compreensão dos mecanismos envolvidos no processo de regeneração do músculo cardíaco isquêmico, através da terapia celular, associada ou não a terapia gênica, com conseqüente recuperação da função cardíaca, em ratos infartados (modeloIAM).  ABSTRACT In spite of clinical, surgical and pharmacological advances, the currently available methods are not totally effective in treating advanced stage ischemic cardiopathy, permitting functional cardiomiocyte loss which leads to ventricle remodeling, progressive loss of ventricle function and the development of cardiac insufficiency. Recent advances in understanding stem cell biology have established the concept of cellular transplant to substitute non-functional cells. Myocardium regeneration is being greatly considered for such procedure. Our main goal is the development of a safe and effective pre-clinical protocol, which could contribute to clarify the mechanisms involved in myocardium regeneration using cellular therapy, combined or not with gene therapy, leading to cardiac function restoration in rats (IAM model).  Keywords: Stem Cell, myocardium regeneration, cell therapy

Terapia Celular para o Tratamento de Cardiopatias Isquêmicas: Desenvolvimento de um Protocolo Pré-clinico

RESUMEN Apesar dos avanços clínicos, cirúrgicos e farmacológicos, quando a doença cardíaca isquêmica é muita avançada e difusa, os métodos atualmente disponíveis não são totalmente efetivos para evitar a perda de cardiomiócitos funcionais. Isso acarretará alterações na geometria ventricular (remodelamento), com perda progressiva da função ventricular e desenvolvimento de insuficiencia cardíaca. Recentes avanços na compreensão da biologia das células-tronco reinstalaram o conceito de transplante celular para substituir células não funcionais. A regeneração do miocárdio tem despertado um crescente interesse visando atender este propósito. A proposta deste trabalho é o de desenvolver um protocolo pré-clínico seguro e eficiente que possa contribuir para uma melhor compreensão dos mecanismos envolvidos no processo de regeneração do músculo cardíaco isquêmico, através da terapia celular, associada ou não a terapia gênica, com conseqüente recuperação da função cardíaca, em ratos infartados (modeloIAM).  ABSTRACT In spite of clinical, surgical and pharmacological advances, the currently available methods are not totally effective in treating advanced stage ischemic cardiopathy, permitting functional cardiomiocyte loss which leads to ventricle remodeling, progressive loss of ventricle function and the development of cardiac insufficiency. Recent advances in understanding stem cell biology have established the concept of cellular transplant to substitute non-functional cells. Myocardium regeneration is being greatly considered for such procedure. Our main goal is the development of a safe and effective pre-clinical protocol, which could contribute to clarify the mechanisms involved in myocardium regeneration using cellular therapy, combined or not with gene therapy, leading to cardiac function restoration in rats (IAM model).  Keywords: Stem Cell, myocardium regeneration, cell therapy

Non-unitary Leptonic Mixing and Leptogenesis

We investigate the relation between non-unitarity of the leptonic mixing matrix and leptogenesis. We discuss how all parameters of the canonical type-I seesaw mechanism can, in principle, be reconstructed from the neutrino mass matrix and the deviation of the effective low-energy leptonic mixing matrix from unitary. When the mass M' of the lightest right-handed neutrino is much lighter than the masses of the others, we show that its decay asymmetries within flavour-dependent leptogenesis can be expressed in terms of two contributions, one depending on the unique dimension five (d=5) operator generating neutrino masses and one depending on the dimension six (d=6) operator associated with non-unitarity. In low-energy seesaw scenarios where small lepton number violation explains the smallness of neutrino masses, the lepton number conserving d=6 operator contribution generically dominates over the d=5 operator contribution which results in a strong enhancement of the flavour-dependent decay asymmetries without any resonance effects. To calculate the produced final baryon asymmetry, the flavour equilibration effects directly related to non-unitarity have to be taken into account. In a simple realization of this non-unitarity driven leptogenesis, the lower bound on M' is found to be about 10^8 GeV at the onset of the strong washout regime, more than one order of magnitude below the bound in "standard" thermal leptogenesis.Comment: 19 pages, REVTeX4, 2 eps and 2 axodraw figure

Advising adolescents on the use of psychotropic medication: attitudes among medical and psychology students

There is evidence that medical students are more aware of the benefits of psychotropic treatment than are members of the general public, and that the more knowledge students acquire about psychiatry and pharmacology, the more favorable their attitudes become towards psychotropic drugs and other treatments. Objectives: This study among students investigates the relationship between certain aspects of personality and attitudes towards advising adolescents with psychosocial problems about the use of psychotropic medication. Methods: Two groups of healthcare students were recruited from universities in Eastern France. 41 fourth-year medical students (MS) who had completed their psychiatry course, and 76 thirdyear psychology students (PS) in the faculty of human sciences. Respondents completed a selfadministered instrument (20 brief case studies, and a personality inventory) at the end of a lecture. Participation was voluntary and unpaid. Results: MS would recommend psychotropic drugs in 40% of the 20 cases, PS in 27%. MS who would prescribe psychotropic medication differed in personality profile from PS. MS with a tendency to experience anger and related states such as frustration, and who did not see fulfilling moral obligations as important were more likely to prescribe psychotropic drugs. Also more likely to recommend psychotropic drugs, but for different reasons, were PS who were susceptible to stress but not shy or socially anxious, who showed friendliness but little interest in others, and who lacked distance in their decision-making. Conclusion: Health promotion is not simply a matter of educating those young people who take psychotropic drugs – health professionals must also question the criteria that inform their decisions. It is as important to investigate the attitudes of the future health professionals (advisers or prescribers) as it is to focus on consumer-related issues

Where form and substance meet: using the narrative approach of re-storying to generate research findings and community rapprochement in (university) mathematics education

Storytelling is an engaging way through which lived experience can be shared and reflected upon, and a tool through which difference, diversity—and even conflict—can be acknowledged and elaborated upon. Narrative approaches to research bring the richness and vibrancy of storytelling into how data is collected and interpretations of it shared. In this paper, I demonstrate the potency of the narrative approach of re-storying for a certain type of university mathematics education research (non-deficit, non-prescriptive, context-specific, example-centred and mathematically focused) conducted at the interface of two communities: mathematics education and mathematics. I do so through reference to Amongst Mathematicians (Nardi, 2008), a study carried out in collaboration with 20 university mathematicians from six UK mathematics departments. The study deployed re-storying to present data and analyses in the form of a dialogue between two fictional, yet entirely data-grounded, characters—M, mathematician, and RME, researcher in mathematics education. In the dialogues, the typically conflicting epistemologies—and mutual perceptions of such epistemologies—of the two communities come to the fore as do the feasibility-of, benefits-from, obstacles-in and conditions-for collaboration between these communities. First, I outline the use of narrative approaches in mathematics education research. Then, I introduce the study and its use of re-storying, illustrating this with an example: the construction of a dialogue from interview data in which the participating mathematicians discuss the potentialities and pitfalls of visualisation in university mathematics teaching. I conclude by outlining re-storying as a vehicle for community rapprochement achieved through generating and sharing research findings—the substance of research—in forms that reflect the fundamental principles and aims that underpin this research. My conclusions resonate with sociocultural constructs that view mathematics teacher education as contemporary praxis and the aforementioned inter-community discussion as taking place within a third space

Phenomenological Consequences of sub-leading Terms in See-Saw Formulas

Several aspects of next-to-leading (NLO) order corrections to see-saw formulas are discussed and phenomenologically relevant situations are identified. We generalize the formalism to calculate the NLO terms developed for the type I see-saw to variants like the inverse, double or linear see-saw, i.e., to cases in which more than two mass scales are present. In the standard type I case with very heavy fermion singlets the sub-leading terms are negligible. However, effects in the percent regime are possible when sub-matrices of the complete neutral fermion mass matrix obey a moderate hierarchy, e.g. weak scale and TeV scale. Examples are cancellations of large terms leading to small neutrino masses, or inverse see-saw scenarios. We furthermore identify situations in which no NLO corrections to certain observables arise, namely for mu-tau symmetry and cases with a vanishing neutrino mass. Finally, we emphasize that the unavoidable unitarity violation in see-saw scenarios with extra fermions can be calculated with the formalism in a straightforward manner.Comment: 22 pages, matches published versio

New physics searches at near detectors of neutrino oscillation experiments

We systematically investigate the prospects of testing new physics with tau sensitive near detectors at neutrino oscillation facilities. For neutrino beams from pion decay, from the decay of radiative ions, as well as from the decays of muons in a storage ring at a neutrino factory, we discuss which effective operators can lead to new physics effects. Furthermore, we discuss the present bounds on such operators set by other experimental data currently available. For operators with two leptons and two quarks we present the first complete analysis including all relevant operators simultaneously and performing a Markov Chain Monte Carlo fit to the data. We find that these effects can induce tau neutrino appearance probabilities as large as O(10^{-4}), which are within reach of forthcoming experiments. We highlight to which kind of new physics a tau sensitive near detector would be most sensitive.Comment: 20 pages, 2 figures, REVTeX