1,408 research outputs found
Energías no convencionales : biocombustibles
Fil: Romano, Silvia Daniela. Universidad de Buenos Aires. Facultad de Ingeniería. Grupo de Energías Renovables; ArgentinaEntre los principales atractivos de los biocombustibles se encuentra el hecho de que se\nobtienen a partir de recursos renovables, generan menos emisiones, son\nbiodegradables y brindan la posibilidad de diversificar la matriz energética. Además,\nvarios de ellos se producen a partir de residuos o sustancias no alimenticias. La\nFacultad de Ingeniería de la UBA se constituyó en los últimos años como una de las\nprincipales fuentes de investigación sobre energías no convencionales. En su sede de\nPaseo Colón, ya se inauguró la primera planta piloto de biodiésel del país
Leptomeningitis in a person with radiologically isolated syndrome and latent tuberculosis. A case report with implications for clinical research
A 39-year-old man, followed with serial MRI of CNS for a radiologically isolate syndrome (RIS, a recently described condition considered a subclinical form of MS), was hospitalized for the occurrence of a leptomeningitis. Routine blood tests and contrast enhanced total body CT scan were unremarkable. Cerebrospinal fluid (CSF) examination showed increase of cells (22 mononuclear cells/mm3), albumin (294 mg/L), immunoglobilins G (161 mg/L) and Link Index (1.9), with 17 oligoclonal bands. Microbiological examinations of CSF (including those for Koch’s Bacillus) were negative. The Mantoux reaction and the QuantiFERON test were positive, featuring a latent tuberculosis (TB). The patient started prophylaxis with rifampicin and isoniazid for four months, until a new MRI showed the disappearance of the leptomeningeal enhancement, and the stability of white matter brain and spinal cord lesions. Two other MRI scans showed a new brain Gd-enhancing lesion nine month after anti-tubercular therapy and, after additional six months, new cerebral and spinal cord areas. This case provides the following suggestions about the effects of TB infection and related therapies on the underlying autoimmune status: the infection, while actively present, did not exacerbate the RIS condition; the worsening nine months after the prophylaxis discontinuation might have been the ‘natural’ evolution of RIS condition. Alternative speculative hypotheses include a remote effect of the infection, of isoniazid (that was reported in some cases to trigger MS), or the result of the clearance of the infection itself. Irrespective of the existence of any interaction between RIS and TB infection, It seems important to collect cases with MS-related diseases and concomitant infections, that may provide clues about disease pathogenesis and treatment
Performance Evaluation of a Novel Inductive Atmosphere-Breathing EP System
Challenging space mission scenarios include those in low altitude orbits, where the atmosphere creates significant drag to the S/C and forces their orbit to an early decay. An atmosphere-breathing electric propulsion system (ABEP) ingests the residual atmosphere through an intake and uses it as propellant for an electric thruster that compensates the drag. Theoretically applicable to any planet with atmosphere, the system might allow to orbit for an unlimited period without carrying propellant on-board. IRS has several decades of heritage on the development of inductively heated plasma generators (IPG). Such devices are electrodeless, therefore issues of potential electrode erosion are eliminated. This paper deals with the complete refurbishment of a facility that was previously used for RIT testing, for the use of IPG6-S, a small scale IPG with an input power up to 3.5 kW. This facility allows more reliable test conditions. First operational and performance tests of IPG6-S have been performed. IPG6-S serves as test bed for the development of an inductive plasma thruster (IPT) for ABEP application. A newly designed water-cooled de Laval nozzle has been built and applied to IPG6-S. The nozzle is modular, it has the possibility of having various configurations so to assess its performance in terms of plasma acceleration and thrust production. Within this paper plasma plume energy has been measured by means of a cavity calorimeter and correlated to current, power, and pressure in the injector head.Peer ReviewedPostprint (published version
Collaboration between a human group and artificial intelligence can improve prediction of multiple sclerosis course. A proof-of-principle study
Background: Multiple sclerosis has an extremely variable natural course. In most patients, disease starts with a relapsing-remitting (RR) phase, which proceeds to a secondary progressive (SP) form. The duration of the RR phase is hard to predict, and to date predictions on the rate of disease progression remain suboptimal. This limits the opportunity to tailor therapy on an individual patient's prognosis, in spite of the choice of several therapeutic options. Approaches to improve clinical decisions, such as collective intelligence of human groups and machine learning algorithms are widely investigated. Methods: Medical students and a machine learning algorithm predicted the course of disease on the basis of randomly chosen clinical records of patients that attended at the Multiple Sclerosis service of Sant'Andrea hospital in Rome. Results: A significant improvement of predictive ability was obtained when predictions were combined with a weight that depends on the consistence of human (or algorithm) forecasts on a given clinical record. Conclusions: In this work we present proof-of-principle that human-machine hybrid predictions yield better prognoses than machine learning algorithms or groups of humans alone. To strengthen this preliminary result, we propose a crowdsourcing initiative to collect prognoses by physicians on an expanded set of patients
Autophagy: A necessary process during the Trypanosoma cruzi life-cycle
Autophagy is a well-conserved process of self-digestion of intracellular components. T. cruzi is a protozoan parasite with a complex life-cycle that involves insect vectors and mammalian hosts. Like other eukaryotic organisms, T. cruzi possesses an autophagic pathway that is activated during metacyclogenesis, the process that generates the infective forms of parasites. In addition, it has been demonstrated that mammalian autophagy has a role during host cell invasion by T. cruzi, and that T. cruzi can modulate this process to its own benefit. This review describes the latest findings concerning the participation of autophagy in both the T. cruzi differentiation processes and during the interaction of parasites within the host cells. Data to date suggest parasite autophagy is important for parasite survival and differentiation, which offers interesting prospects for therapeutic strategies. Additionally, the interruption of mammalian autophagy reduces the parasite infectivity, interfering with the intracellular cycle of T. cruzi inside the host. However, the impact on other stages of development, such as the intracellular replication of parasites is still not clearly understood. Further studies in this matter are necessaries to define the integral effect of autophagy on T. cruzi infection with both in vitro and in vivo approaches.Fil: Salassa, Betiana Nebaí. Universidad Nacional de Cuyo. Facultad de Odontologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo; ArgentinaFil: Romano, Patricia Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin
Sources for the study of ancient thermalism: a new proposal for editing and translation
En el presente artículo presentamos un nuevo proyecto interdisciplinar consistente en una colección de textos, en formato digital, que recogerá las fuentes griegas y latinas sobre el fenómeno del termalismo mineromedicinal antiguo. La colección permitirá aunar, por primera vez, distintos tipos de fuentes en una única publicación, así como reunir, analizar y ampliar de forma ágil el trabajo ya existente en la bibliografía sobre el tema desde el punto de vista filológico, histórico, arqueológico y epigráfico. Se dará así acceso directo a las fuentes originales para el estudio del termalismo antiguo con una visión crítica, innovadora y actualizada, algo que la comunidad de investigadores sobre el tema viene reclamando desde hace tiempo. Esta nueva herramienta de trabajo será accesible online para todos los interesados en la materia, con una clara pretensión de continuidad y duración, pero siempre respaldada por criterios científicos y especializados, y en constante revisión.This article presents a new interdisciplinary project for compiling a digital collection of Greek and Latin sources dealing with ancient mineral-medicinal thermalism. For the first time ever, the project bring together different types of historical and textual sources in a single publication, and also gather, analyse and expand on previous bibliographic attempts on this subject from the philological, historical, archaeological, and ephigraphic perspective. The collection will provide direct access to original sources for the study of ancient thermalism including translations into English and Spanish with a critical, innovative, and updated vision, meeting a long-standing demand by the community of researchers in this area. This new tool will be accessible online for everyone interested in this topic, and aims for both continuity and permanence, while always being endorsed by scientific and specialized criteria, and in constant review
Alternative Properties in Liquid Fuels and Blends
This work summarises the results of the research program at the Renewable Energy Group (GER) of the University of Buenos Aires on alternative properties for the characterization of liquid fuels. The study included fossil fuels: diesel fuel, gasoline, and methanol, and biofuels: biodiesel from different feedstocks and bioethanol. Blends of diesel fuel/biodiesel, gasoline/bioethanol, gasoline/methanol, biodiesel/butanol, and diesel fuel/biodiesel/butanol were also studied. The electrical, acoustical, and optical properties of fuels and blends were determined as a function of temperature and composition. From these results, the composition of blends was accurately estimated from measurements of permittivity and temperature. The research program included the study of correlations of the alternative properties with those indicated in the international quality standards for liquid fuels (kinematic viscosity, methanol content, flash point). These correlations make possible to verify the quality of liquid fuels with simpler and more convenient measurements in industrial settings, and also in the laboratory.Fil: Romano, Silvia Daniela. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Sorichetti, P. A.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física; Argentin
Trama burocrática y documentos secretos. Dispositivos 'legales' para la represión de los trabajadores de la administración pública de Córdoba (1974-1978)
This work continues the investigation of bureaucratic practices aimed at disciplining and repressing the workers of the Córdoba public administration in the period between the police coup, known as “Navarrazo”, which removed the governor and deputy governor (February 28, 1974 ) and the first three years of the dictatorship established by the National Reorganization Process (PRN, March 24, 1976). During this period, various provisions were applied, such as the expendable law and the Public Employee Statute (1974) that later overlapped with “de facto laws” passed during the PRN, such as 5911 and 5913 (1976, down for reasons of security and expendability, respectively) with the purpose of "purifying" the public administration. The arbitrariness of the measures made use of profuse regulations and routine, bureaucratic and legalistic practices, which coexisted with illegal repression and State terrorism, which is reflected in the significant number of missing and murdered workers. Within this framework, we will focus on two aspects related to said practices: layoffs and resignations of personnel, which grew exponentially between 1976 and 1978. At the same time, we will provide new evidence on the close coordination between de facto authorities, their bureaucratic-administrative procedures and the intelligence services for the ideological persecution and repression of public employees. For this we resort, among others, to “secret documents” kept in the Government Archive of the Province of Córdoba).Este trabajo continúa la indagación sobre prácticas burocráticas orientadas al disciplinamiento y la represión de los trabajadores de la administración pública de Córdoba en el período que transcurre entre el golpe policial, conocido como “Navarrazo”, que destituyó al gobernador y vicegobernador (28 de febrero 1974) y los tres primeros años de la dictadura instaurada por el Proceso de Reorganización Nacional (PRN, 24 de marzo 1976). En ese período se aplicaron diversos dispositivos, como la ley de prescindibilidad y el Estatuto del Empleado Público (1974) que se solaparon luego con “leyes de facto” dictadas durante el PRN, tales como la 5911 y 5913 (1976, baja por razones de seguridad y prescindibilidad, respectivamente) con el propósito de “depurar” la administración pública. La arbitrariedad de las medidas se sirvió de una profusa normativa y de prácticas rutinarias, burocráticas y legalistas, que coexistieron con la represión ilegal y el terrorismo de Estado, de lo que da cuenta el importante número de trabajadores desaparecidos y asesinados. En ese marco, haremos foco en dos aspectos vinculados a dichas prácticas: las cesantías y las renuncias de personal, que crecieron exponencialmente entre 1976 y 1978. Paralelamente, aportaremos nueva evidencia sobre la articulación estrecha entre las autoridades de facto, sus procedimientos burocrático-administrativos y los servicios de inteligencia para la persecución ideológica y la represión de los empleados públicos. Para ello recurrimos, entre otros, a “documentos secretos” custodiados en el Archivo de Gobierno de la Provincia de Córdoba
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