Heat Flow in Classical and Quantum Systems and Thermal Rectification

The understanding of the underlying dynamical mechanisms which determine the macroscopic laws of heat conduction is a long standing task of non-equilibrium statistical mechanics. A better understanding of the mechanism of heat conduction may lead to potentially interesting applications based on the possibility to control the heat flow. Indeed, different models of thermal rectifiers has been recently proposed in which heat can flow preferentially in one direction. Although these models are far away from a prototype realization, the underlying mechanisms are of very general nature and, as such, are suitable of improvement and may eventually lead to real applications. We briefly discuss the problem of heat transport in classical and quantum systems and its relation to the chaoticity of the dynamics. We then study the phenomenon of thermal rectification and briefly discuss the different types of microscopic mechanisms that lead to the rectification of heat flow.Comment: 11 pages, 5 figures. Contribution to the proceedings of CTNEXT0

Verdades e mitos sobre o cogumelo Agaricus blazei

The mushroom Agaricus blazei Murrill was discovered in Piedade, state of São Paulo, Brazil, and sent to Japan to be studied for its medicinal properties. Studies in guinea pigs revealed antitumor properties, triggering Japanese importation of A. blazei from Brazil. Because of its high price on the international market, many companies and rural growers produce A. blazei as alternative crop to increase income, but because interest in this mushroom occurred suddenly there has not been enough time for the scientific community to investigate it and, technology used for its cultivation is still based on empirical rules. There are also some contradicting data regarding the classification of this mushroom, and its antitumor properties still need to be confirmed in humans.O cogumelo Agaricus blazei Murrill foi descoberto na cidade de Piedade, Estado de São Paulo, Brasil, e enviado para o Japão para o estudo das suas propriedades medicinais. Com a descoberta das suas propriedades antitumorais, comprovadas em cobaias, o Japão passou a importar esse cogumelo do Brasil. Devido ao seu elevado preço no mercado internacional, muitas empresas e produtores rurais passaram a buscar nesse cogumelo uma nova alternativa de renda. Diante de um interesse tão repentino, não houve tempo para que a comunidade científica pesquisasse o assunto, de maneira que a tecnologia de cultivo é ainda muito empírica. Além disso, existem informações contraditórias acerca da classificação desse cogumelo e as suas propriedades antitumorais ainda precisam ser confirmadas em seres humanos

Inflation, moduli (de)stabilization and supersymmetry breaking

We study the cosmological inflation from the viewpoint of the moduli stabilization. We study the scenario that the superpotential has a large value during the inflation era enough to stabilize moduli, but it is small in the true vacuum. This scenario is discussed by using a simple model, one type of hybrid models.Comment: 17 pages, 7 figure

Moduli-mixing racetrack model

We study supersymmetric models with double gaugino condensations in the hidden sector, where the gauge couplings depend on two light moduli of superstring theory. We perform a detailed analysis of this class of model and show that there is no stable supersymmetric minimum with finite vacuum values of moduli fields. Instead, we find that the supersymmetry breaking occurs with moduli stabilized and negative vacuum energy. That yields moduli-dominated soft supersymmetry breaking terms. To realize slightly positive (or vanishing) vacuum energy, we add uplifting potential. We discuss uplifting does not change qualitatively the vacuum expectation values of moduli and the above feature of supersymmetry breaking.Comment: 23 pages, 4 eps figure

Tevatron Signatures of an R-parity Violating Supersymmetric Theory

We show that an R-parity violating supersymmetric scenario which can account for the atmospheric nu(mu) deficit has testable signals at the Fermilab Tevatron with upgraded energy and luminosity. The explanation of neutrino masses and maximal nu(mu)-nu(tau) oscillation in terms of bilinear R-violating terms in the superpotential associates comparable numbers of muons and tau's resulting from decays of the lightest neutralino. We show that this should lead to like-sign dimuons and ditaus with substantial rates, in a form that separates them from standard model backgrounds and other signals of supersymmetry. One here also has the possibility of completely reconstructing the lightest neutralino.Comment: 10 pages, 4 figures (ps files included). Matches published versio

Tratamento da rejeição endotelial pós-ceratoplastia penetrante através da associação do pulso de metilprednisolona intravenosa com acetato de prednisolona tópico: seguimento de um ano

OBJECTIVE: To analyze the recovery of visual acuity (VA) and graft survival after first episode of endothelial rejection in penetrating keratoplasty (PKP) treated with intravenous (IV) and topic corticosteroid. METHODS: Interventional, prospective, non-comparative case series study evolving 32 PKP patients in one year follow up, who presented first episode of corneal endothelial rejection. The patients were submitted to 500 mg IV injection of methylprednisolone in association with topical prednisolone. Main outcome measures included VA recovery and corneal edema regression. Second outcome included new rejections and graft failure. Multivariate analysis techniques were used to estimate rates of graft outcome events and the impact of risk factors. RESULTS: A total of 32 eyes from 32 patients (13 male and 19 female) were included in the study. The mean VA (in number of letters) before rejection was 48 (22 to 88 letters). Patients treated within 7 days or less of initial symptoms had better VA recovery, corneal edema regression and less graft failure (p<0.001). Patients with previous ocular surgery had worse VA recovery and more graft failure (p<0.047). CONCLUSION: The association between the other risk factors and the outcomes did not reach statistical significance in the multivariate model because of the small numbers of patients. Methylprednisolone in association with topical prednisolone is an alternative treatment for graft rejection. Our study showed that patients treated within 7 days of symptoms and no previous anterior segment surgery had better visual outcome and graft survival after treatment.OBJETIVO: Analisar a recuperação da acuidade visual (AV) e sobrevivência do enxerto após primeiro episódio de rejeição endotelial em ceratoplastia penetrante (PK) em pacientes submetidos ao corticóide intravenoso (IV) associado ao tópico. MÉTODOS: Estudo descritivo, prospectivo, tipo série de casos envolvendo 32 pacientes com PK tratados com 2 doses de 500mg de metilprednisolona IV (com intervalo de 1 semana) associado ao acetato de prednisolona 1%. O parâmetro principal analisado foi a recuperação da AV e a regressão do edema corneano. O parâmetro secundário utilizado foi a recorrência das rejeições e a falência do enxerto. RESULTADOS: Um total de 32 olhos de 32 pacientes foram incluídos no estudo (13 homens e 19 mulheres). A média da AV (em número de letras) foi 48. Pacientes tratados dentro de 7 dias ou menos após o surgimento dos sintomas apresentaram melhor recuperação da AV e menor falência do enxerto (p<0,001). Pacientes com antecedente de cirurgia ocular anterior à PK apresentaram pior recuperação da AV e maior índice de falência do enxerto. CONCLUSÃO: A associação entre os outros fatores de risco não atingiram significância estatística devido ao baixo número de pacientes do estudo. A metilprednisolona IV em associação com a prednisolona tópica pode ser uma alternativa para o tratamento da rejeição endotelial do enxerto. Nossos resultados sugerem que pacientes tratados dentro de 7 dias do início dos sintomas e a ausência de cirurgia ocular prévia apresentam melhor recuperação da AV e melhor sobrevivência do enxerto.424

DiGeorge Syndrome: a not so rare disease

INTRODUCTION: The DiGeorge Syndrome was first described in 1968 as a primary immunodeficiency resulting from the abnormal development of the third and fourth pharyngeal pouches during embryonic life. It is characterized by hypocalcemia due to hypoparathyroidism, heart defects, and thymic hypoplasia or aplasia. Its incidence is 1:3000 live births and, despite its high frequency, little is known about its natural history and progression. &#8592;This is probably due to diagnostic difficulties and the great variety of names used to describe it, such as velocardiofacial, Shprintzen, DiGeorge, and CATCH 22 Syndromes, as well as conotruncal facial anomaly. All represent the same genetic condition, chromosome 22q11.2 deletion, which might have several clinical expressions. OBJECTIVES: To describe clinical and laboratorial data and phenotypic characteristics of patients with DiGeorge Syndrome. METHODS: Patients underwent standard clinical and epidemiological protocol and tests to detect heart diseases, facial abnormalities, dimorphisms, neurological or behavioral disorders, recurrent infections and other comorbidities. RESULTS: Of 14 patients (8m - 18y11m), only one did not have 22q11.2 deletion detected. The main findings were: conotruncal malformation (n = 12), facial abnormalities (n = 11), hypocalcemia (n = 5) and low lymphocyte count (n=2). CONCLUSION: The authors pointed out the necessity of DGS suspicion in all patient presenting with heart defects, facial abnormalities (associated or not with hypocalcemia), and immunological disorders because although frequency of DGS is high, few patients with a confirmed diagnosis are followed up

Ocular Masquerade Syndrome Associated With Extranodal Nasal Natural Killer/t-cell Lymphoma: Case Report.

A 33-year-old woman complained of unilateral eyelid edema and blurred vision. Initial ophthalmic examination disclosed anterior chamber reaction with keratic precipitates on the cornea, without posterior abnormalities. Anterior uveitis was treated. Despite that, patient showed rapidly progressive unilateral vision loss with optic nerve swelling. Systemic workup was inconclusive, as well as cranial magnetic resonance imaging and cerebrospinal fluid examination. Based on the hypothesis of optic neuritis, intravenous methylprednisolone pulse was performed with no success. During the following days, the patient presented pericardial effusion and cardiac tamponade, progressing to death. Necropsy was performed and diagnosis of extranodal natural killers/T-cell lymphoma, nasal type with ocular involvement was confirmed by immunohistochemistry.75430-

Can Inflation Induce Supersymmetry Breaking in a Metastable Vacuum?

We argue that fields responsible for inflation and supersymmetry breaking are connected by gravitational couplings. In view of the recent progress in studying supersymmetry breaking in a metastable vacuum, we have shown that in models of supersymmetric hybrid inflation, where R-symmetry plays an important role, the scale of supersymmetry breaking is generated dynamically at the end of inflation and turns out to be consistent with gravity mediation.Comment: 5 pages, Latex, Footnote and references added, Journal versio

Constraining Supergravity Scenarios through the b→s,γb\to s,\gamma Decay.

We evaluate the branching ratio BR($b\rightarrow s,\gamma$) in the minimal supersymmetric standard model (MSSM), determining the corresponding phenomenological restrictions on two attractive supergravity scenarios, namely minimal supergravity and a class of models with a natural solution to the $\mu$ problem. We have included in the calculation some one--loop refinements that have a substantial impact on the results. The numerical results show some disagreements with part of the previous results in the literature, while they are in agreement with others. For minimal supergravity the CLEO upper and lower bounds put important restrictions on the scalar and gaugino masses in both cases $\mu0$. For the other supergravity scenarios the relevant CLEO bound is the upper one. It is stressed the fact that an eventual improvement of the experimental bounds of order $10^{-4}$ would strengthen the restrictions on the MSSM dramatically. This would be enough to discard these supergravity scenarios with $\mu<0$ if no discrepancy is found with the standard model prediction, while for $\mu>0$ there will remain low-energy windows.Comment: 13 pages + 8 figures included in a separate file, Latex, requires psfig.sty. We have corrected a mistake affecting some figures and their corresponding quotations in the text, as well as several misprints