Poor Outcome in a Mitochondrial Neurogastrointestinal Encephalomyopathy Patient with a Novel TYMP Mutation: The Need for Early Diagnosis.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a devastating autosomal recessive disorder due to mutations in TYMP, which cause loss of function of thymidine phosphorylase (TP), nucleoside accumulation in plasma and tissues and mitochondrial dysfunction. The clinical picture includes progressive gastrointestinal dysmotility, cachexia, ptosis and ophthalmoparesis, peripheral neuropathy and diffuse leukoencephalopathy, which usually lead to death in early adulthood. Therapeutic options are currently available in clinical practice (allogeneic hematopoietic stem cell transplantation and carrier erythrocyte entrapped TP therapy) and newer, promising therapies are expected in the near future. However, successful treatment is strictly related to early diagnosis. We report on an incomplete MNGIE phenotype in a young man harboring the novel heterozygote c.199 C>T (Q67X) mutation in exon 2, and the previously reported c.866 A>C (E289A) mutation in exon 7 in TYMP. The correct diagnosis was achieved many years after the onset of symptoms and unfortunately, the patient died soon after diagnosis because of multiorgan failure due to severe malnutrition and cachexia before any therapeutic option could be tried. To date, early diagnosis is essential to ensure that patients have the opportunity to be treated. MNGIE should be suspected in all patients who present with both gastrointestinal and nervous system involvement, even if the classical complete phenotype is lacking

Determinación de la nucleación de grietas por fatiga en componentes de aeronaves

Este trabajo se desarrolla en base a una falla estructural detectada en una aeronave agrícola durante la ejecución rutinaria de tareas de mantenimiento. En la platabanda inferior del larguero principal, se encontraron grietas que nuclearon en la pared interna de los agujeros donde se alojan los bulones que constituyen los elementos de unión de las semi-alas. Con el propósito de evaluar el diseño, descubrir potenciales regiones de acumulación de daño y estimar el número de ciclos de carga aplicables hasta la iniciación de algún defecto, se realiza un estudio sobre el probable mecanismo de nucleación, se define una metodología de análisis, se estipula un perfil de misión “típico” y su espectro de cargas, se calculan tensiones y deformaciones actuantes y se estima la vida a fatiga de los elementos componentes. Las tensiones actuantes en la región de interés resultan en estados multiaxiales y no proporcionales, por lo que, para el análisis de durabilidad, se recurre a una aproximación strain-life de plano crítico. Los resultados permiten identificar aquellas regiones de la unión del ala con mayor probabilidad de acumulación de daño y consecuente nucleación de grietas por fatiga, prever sus orientaciones, seleccionar métodos de inspección y estimar tiempos para la adición de eventuales inspecciones al plan de mantenimiento.Facultad de Ingenierí

k-Anomalies and Space-Time Supersymmetry in the Green-Schwarz Heterotic Superstring

The computation of $\kappa$-anomalies in the Green-Schwarz heterotic superstring sigma-model and the corresponding Wess-Zumino consistency condition constitute a powerful alternative approach for the derivation of manifestly supersymmetric string effective actions. With respect to the beta-function approach this technique presents the advantage that a result which is obtained with the computation of beta-functions at $n$ loops can be obtained through the calculation of $\kappa$-anomalies at \hbox{$n-1$} loops. In this paper we derive by a direct one-loop perturbative computation the $\kappa$-anomaly associated to the Yang-Mills Chern-Simons threeform and, for the first time, the one associated to the Lorentz Chern-Simons threeform. Contrary to what is often stated in the literature we show that the Lorentz $\kappa$-anomaly gets contributions from the integration over both the fermionic {\it and\/} bosonic degrees of freedom of the string. A careful analysis of the absolute coefficients of all these anomalies reveals that they can be absorbed by setting dH={\alpha'\over4}(\trace F^2-\trace R^2), where $\alpha'$ is the string tension, the expected result. We show that this relation ensures also the absence of gauge and Lorentz anomalies in the sigma-model effective action. We evidenciate the presence of infrared divergences.Comment: 50 pages, latex (uses equations.sty, feynman.tex and a4.sty), DFPD/94/TH/4

Determinación de la nucleación de grietas por fatiga en componentes de aeronaves

Este trabajo se desarrolla en base a una falla estructural detectada en una aeronave agrícola durante la ejecución rutinaria de tareas de mantenimiento. En la platabanda inferior del larguero principal, se encontraron grietas que nuclearon en la pared interna de los agujeros donde se alojan los bulones que constituyen los elementos de unión de las semi-alas. Con el propósito de evaluar el diseño, descubrir potenciales regiones de acumulación de daño y estimar el número de ciclos de carga aplicables hasta la iniciación de algún defecto, se realiza un estudio sobre el probable mecanismo de nucleación, se define una metodología de análisis, se estipula un perfil de misión “típico” y su espectro de cargas, se calculan tensiones y deformaciones actuantes y se estima la vida a fatiga de los elementos componentes. Las tensiones actuantes en la región de interés resultan en estados multiaxiales y no proporcionales, por lo que, para el análisis de durabilidad, se recurre a una aproximación strain-life de plano crítico. Los resultados permiten identificar aquellas regiones de la unión del ala con mayor probabilidad de acumulación de daño y consecuente nucleación de grietas por fatiga, prever sus orientaciones, seleccionar métodos de inspección y estimar tiempos para la adición de eventuales inspecciones al plan de mantenimiento.Facultad de Ingenierí

Sustaining Economic Exploitation of Complex Ecosystems in Computational Models of Coupled Human-Natural Networks

Understanding ecological complexity has stymied scientists for decades. Recent elucidation of the famously coined "devious strategies for stability in enduring natural systems" has opened up a new field of computational analyses of complex ecological networks where the nonlinear dynamics of many interacting species can be more realistically mod-eled and understood. Here, we describe the first extension of this field to include coupled human-natural systems. This extension elucidates new strategies for sustaining extraction of biomass (e.g., fish, forests, fiber) from ecosystems that account for ecological complexity and can pursue multiple goals such as maximizing economic profit, employment and carbon sequestration by ecosystems. Our more realistic modeling of ecosystems helps explain why simpler "maxi-mum sustainable yield" bioeconomic models underpinning much natural resource extraction policy leads to less profit, biomass, and biodiversity than predicted by those simple models. Current research directions of this integrated natu-ral and social science include applying artificial intelligence, cloud computing, and multiplayer online games

Reinforced feedback in virtual environment for rehabilitation of upper extremity dysfunction after stroke: preliminary data from a randomized controlled trial.

OBJECTIVES: To study whether the reinforced feedback in virtual environment (RFVE) is more effective than traditional rehabilitation (TR) for the treatment of upper limb motor function after stroke, regardless of stroke etiology (i.e., ischemic, hemorrhagic). DESIGN: Randomized controlled trial. Participants. Forty-four patients affected by stroke. Intervention. The patients were randomized into two groups: RFVE (N = 23) and TR (N = 21), and stratified according to stroke etiology. The RFVE treatment consisted of multidirectional exercises providing augmented feedback provided by virtual reality, while in the TR treatment the same exercises were provided without augmented feedbacks. Outcome Measures. Fugl-Meyer upper extremity scale (F-M UE), Functional Independence Measure scale (FIM), and kinematics parameters (speed, time, and peak). RESULTS: The F-M UE (P = 0.030), FIM (P = 0.021), time (P = 0.008), and peak (P = 0.018), were significantly higher in the RFVE group after treatment, but not speed (P = 0.140). The patients affected by hemorrhagic stroke significantly improved FIM (P = 0.031), time (P = 0.011), and peak (P = 0.020) after treatment, whereas the patients affected by ischemic stroke improved significantly only speed (P = 0.005) when treated by RFVE. CONCLUSION: These results indicated that some poststroke patients may benefit from RFVE program for the recovery of upper limb motor function. This trial is registered with NCT01955291