A diffusion limit for a test particle in a random distribution of scatterers

We consider a point particle moving in a random distribution of obstacles described by a potential barrier. We show that, in a weak-coupling regime, under a diffusion limit suggested by the potential itself, the probability distribution of the particle converges to the solution of the heat equation. The diffusion coefficient is given by the Green-Kubo formula associated to the generator of the diffusion process dictated by the linear Landau equation

Derivation of the Fick's Law for the Lorentz Model in a low density regime

We consider the Lorentz model in a slab with two mass reservoirs at the boundaries. We show that, in a low density regime, there exists a unique stationary solution for the microscopic dynamics which converges to the stationary solution of the heat equation, namely to the linear profile of the density. In the same regime the macroscopic current in the stationary state is given by the Fick's law, with the diffusion coefficient determined by the Green-Kubo formula.Comment: 33 pages, 7 figure

Can patients with epilepsy become bone marrow donors? A case report of allogeneic hematopoietic stem transplantation from child with seizures

Hematopoietic stem cell (HSC) transplantation is an important treatment option for malignant and non-malignant hematopoietic disorder in adults and children. For long time epilepsy was temporary exclusion condition to voluntary donation, and donors had to be medication or seizure free. It is still unclear if people with history of epilepsy are indeed potential eligible donors, even if a significant increased risk of adverse events in these donors has not been demonstrated. We studied a 10-year-old boy with symptomatic focal epilepsy who was the only available donor for his monozycote twin, suffering from acute lymphoblastic leukemia. A total of 3.39 x 108/kg HSCs were collected and reinfused to the leukemic brother after conditioning treatment. At the end of follow-up, our epilepsy patient had no consequences and his brother is in complete remission of the disease at 3 years from the transplant procedure. Our observation confirms that a patient with epilepsy can be a donor, without consequences for himself and for the recipient

Il Voyage pittoresque in Puglia e Basilicata: i tempi, le tappe, i temi

Arriving in Puglia in April 1778, the members of the Saint-Non expedition, guided by Dominique Vivant Denon, were aware of starting the most adventurous and unpredictable part of their mission in the Kingdom of Naples and Sicily in search of the testimonies of the ancient glory of the Grande Grèce. In fact, unlike what happened to Naples and Campania, for most of the other territories of the Kingdom it meant building an unprecedented iconographic repertoire, starting from Puglia and Basilicata. The drawings, made by the artists following Denon and faithfully transposed into engraving in the Voyage pittoresque, fulfilled this task.But the diary written by Denon, greatly reduced and reworked by Saint-Non, could not express its full documentary expression, until it was published by his friend Benjamin de Laborde in the form of notes to the French edition of Travels in the Two Sicilies by Henry Swinburne (1785-1787).It is this version of Denon's diary, revisited by the author and never reprinted in an autonomous form, that forms the guiding thread of the first part of this contribution dedicated to the times and stages of Voyage, while the second part mainly follows the version of Saint-Non to describe all the illustrations of the volumes, including those of the sites of Apulia and Lucania, here, for the first time, systematically reconsidered from the thematic point of view.Arrivando in Puglia nell’aprile 1778, i membri della spedizione Saint-Non guidati da Dominique Vivant Denon erano consapevoli di iniziare la parte più avventurosa e imprevedibile della loro missione nel Regno di Napoli e di Sicilia alla ricerca delle testimonianze dell’antica gloria della Grande Grèce. Infatti, a differenza di quanto era avvenuto per Napoli e la Campania, per gran parte degli altri territori del regno si sarebbe trattato di costruire un inedito repertorio iconografico, a cominciare dalla Puglia e dalla Basilicata. I disegni eseguiti dagli artisti al seguito di Denon e trasposti fedelmente in incisione nel Voyage pittoresque assolsero questo compito. Ma il diario scritto da Denon, pesantemente ridotto e rielaborato da Saint-Non, non poté esprimere la sua piena espressione documentaria, fino a quando non fu pubblicato dall’amico Benjamin de Laborde in forma di note all’edizione francese dei Travels in the Two Sicilies di Henry Swinburne (1785-1787). Proprio questa versione del diario di Denon, rivisitata dall’autore e mai ristampato in forma autonoma, costituisce il filo conduttore della prima parte di questo contributo dedicato ai tempi e alle tappe del Voyage, mentre la seconda parte segue prevalentemente la versione di Saint-Non per descrivere tutte le illustrazioni dell’opera, comprese quelle dei siti pugliesi e lucani qui per la prima volta sistematicamente riconsiderate dal punto di vista tematico

A Complex Renal Cyst: It Is Time to Call the Oncologist?

Introduction. Hydatid disease is a cyclozoonotic parasitic infestation caused by the cestode Echinococcus granulosus. The cysts mainly arise in the liver (50 to 70%) or lung (20 to 30%), but any other organ can be involved, in abdominal and pelvic locations, as well as in other less common sites, which may make both diagnosis and treatment more complex. Isolated renal involvement is extremely rare. Case Presentation. We report a rare case of isolated renal hydatid disease in a 71-year-old man with a history of vague abdominal pain, anemia, fever, and microhematuria. Ultrasonographic examination revealed a complex cyst in the right kidney, including multiple smaller cysts with internal echoes. A magnetic resonance scan of the abdomen confirmed the findings, and hydatid cyst disease was diagnosed. Right nephrectomy was performed, and microscopic examination confirmed the diagnosis of hydatid cyst. Albendazole, 10 mg/kg per day, was given for 4 weeks (2 weeks preoperatively and 2 weeks postoperatively). Conclusion. Isolated primary hydatidosis of the kidney should always be considered in the differential diagnosis of any cystic renal mass, even in the absence of accompanying involvement of liver or other visceral organs

Multivariate hierarchical model for physical inactivity among public school children

OBJECTIVE: To identify biological and sociodemographic factors associated with physical inactivity in public school children. METHODS: Parents of 2,519 children (49.3% of whom were girls), aged 7 to 10 years (mean = 7.6±0.9 years), from eight public schools in São Paulo, Brazil, completed a self-administered questionnaire. We used multiple correspondence analysis to identify groups of responses related to levels of physical activity and inactivity and to obtain an optimal scale. The cluster analysis identified groups of active and inactive children. The analysis of the receiver operator characteristic (ROC) curve, for the study of diagnostic properties of a simplified scale for physical inactivity derived from the optimal scale, revealed that a cutoff point of 3 had the best sensitivity and specificity, being therefore used as outcome variable in the regression model. A multivariate hierarchical model was built, including distal and proximal categorical variables, with a p < 0.05. RESULTS: Physical inactivity was positively associated with biological factors such as being overweight, being older than 7.5 years, being a female, and having a good appetite, and with socioeconomic factors such as having garbage collected less than twice a week and having mothers who work outside the home. CONCLUSION: The results are consistent with published data about determinant factors of physical activity and inactivity among children, showing that questionnaires answered by parents and submitted to a sophisticated statistical analysis can be used in population-based studies involving children younger than 10 years old.OBJETIVO: Identificar fatores biológicos e sociodemográficos atribuíveis à inatividade física em crianças de escolas públicas. MÉTODOS: Foram estudadas, através de questionário auto-relatado pelos pais, 2.519 crianças (49,3% meninas), de 7 a 10 anos (média = 7,6±0,9 anos), de oito escolas públicas da cidade de São Paulo. Aplicamos a análise de correspondência múltipla para identificar grupos de respostas relacionadas com padrões de atividade e inatividade física e a geração de uma escala ótima. A análise de agrupamento identificou os grupos de crianças ativas e inativas. A análise de curva ROC (receiver operator characteristic), para o estudo das propriedades diagnósticas de uma escala simplificada de inatividade física derivada da escala ótima, mostrou o ponto de corte = 3 como o de melhor sensibilidade e especificidade, sendo utilizado como a variável de resposta no modelo de regressão. Um modelo hierárquico multivariado foi construído, assumindo variáveis categóricas como distais e proximais, adotando-se p < 0,05. RESULTADOS: A inatividade física foi positivamente associada aos fatores determinantes biológicos como sobrepeso, idade maior do que 7,5 anos, sexo feminino e bom apetite, e aos determinantes socioeconômicos como freqüência de coleta de lixo menor do que duas vezes por semana e mães que trabalham fora de casa. CONCLUSÃO: Os resultados são coerentes com os dados publicados sobre fatores determinantes de atividade e inatividade física na infância, indicando que questionários respondidos pelos pais, submetidos a uma análise estatística sofisticada, podem ser viáveis em estudos populacionais envolvendo crianças menores de 10 anos.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaCenter for Physical Activity and Health PromotionCenters for Disease Control and Prevention Division of Nutrition and Physical ActivityUNIFESP-EPM Departamento de PediatriaUNIFESP, EPM, Depto. de PediatriaSciEL

Spinal cord injuries in the absence of post-traumatic radiographic anomalies (SCIWORA). The traumatic moment between patient anterior state and efficient/concurrent causes of injury

Background and aim: Spinal Cord Injury without Radiographic Abnormality (SCIWORA) represents acute traumatic myelopathy in the absence of instrumental evidence of fractures and/or dislocations of the cervical vertebrae. Methods: In this article we present 4 cases of SCIWORA that came to our observation and the medico-legal implications associated with them. Results: In defining the compensation in the context of a private accident policy for traumatic pathologies of the spinal cord, an in-depth medical-legal assessment is essential, based on an accurate examination of the health documentation including the instrumental investigations performed, the anamnesis and an accurate evaluation of the trauma dynamic. The paraphysiological deterioration of organ-tissue structures, identifiable in the concept of "natural variability of biological risk", should be included in the same definition of insured risk by age group, with the consequence that physical conditions that fall within the physiological or paraphysiological definitions, although potentially contributing to injury, do not necessarily exclude compensation.&nbsp;A different concept dominates the variability of the compensation according to a paraphysiological pre-existing condition. The two arguments therefore call for thorough consideration of both the paraphysiological contributing causes of injury and/or impairment as necessarily subject to a preliminary study, which through the clinical and instrumental investigation method, will define the perimeter of functionality

Endoscopic Endonasal Resection of a Schwannoma of the Anterior Cranial Fossa.

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Preventing tomorrow's sudden cardiac death in epilepsy today: what should physicians know about this?

Approximately 1% of the population has epilepsy, the most common neurological disorder. Moreover, people with epilepsy are more likely to die prematurely than those without epilepsy, and the most common epilepsy-related category of death is sudden unexpected death in epilepsy (SUDEP). Information concerning risk factors for SUDEP is conflicting, but potential risk factors include: age, early onset of epilepsy, duration of epilepsy, uncontrolled seizures, seizure frequency, number of antiepileptic drugs and winter temperatures. Additionally, the cause of SUDEP is still unknown; however, the most commonly suggested mechanisms are cardiac abnormalities during and between seizures. This review discusses the epidemiology, risk factors, etiology, and preventative measures in the management of SUDEP.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Laboratório de Neurologia ExperimentalUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaUNIFESP, EPM, Laboratório de Neurologia ExperimentalUNIFESP, EPM, Depto. de FisiologiaSciEL