VIABILIDAD TÉCNICA Y FINANCIERA DE UNA PLANTA PRODUCTORA DE BIODIESEL A PARTIR DE ACEITES VEGETALES NO COMESTIBLES, POTENCIALMENTE PIÑON MANSO (Jatropha curcas L.) EN EL DEPARTAMENTO DE PRESIDENTE HAYES, PARAGUAY.

El presente proyecto tuvo el objetivo de determinar la viabilidad técnica y económica de la producción de biodiesel a partir de aceites vegetales no comestibles en el Paraguay. El estudio de mercado estimó una demanda insatisfecha a nivel local de 55% con una fuerte tendencia a aumentar, debido al establecimiento de la Ley 235/07 que establece la obligatoriedad de la mezcla de biodiesel con gasoil en el territorio paraguayo. El estudio técnico determinó que la planta procesadora tendrá una producción anual de 3.300 m3 de biodiesel y 297 Ton de glicerina cruda. Estará ubicada en el Distrito de Villa Hayes, departamento de Presidente Hayes. La tecnología de producción será mediante el proceso Batch (discontinuo). El estudio organizacional determinó la necesidad de una Gerencia General, una Secretaría, un Departamento de de Producción y un Departamento de Administrativo.Se determinó una Tasa Interna de Retorno (TIR) del 52,45%. El Valor Actual Neto (VAN), a una tasa de descuento de 31,60%, fue de Gs. 1.295.588.875, la relación beneficio/costo obtenida fue de 1,73. Esto comparado con la tasa de oportunidad (31,60), siendo el VAN positivo y la relación beneficio costo mayor que uno, permite concluir la factibilidad financiera del proyecto. Por lo tanto la implantación y operación del proyecto será una actividad económicamente rentable, con existencia de oportunidades en el mercado y técnicamente viable

Análisis del régimen de correlatividades de Ingeniería en Agrimensura mediante CPM

Este trabajo tiene como objetivo analizar el régimen de correlatividades del plan de estudios de Ingeniería en Agrimensura mediante programación por camino crítico, a fin de determinar si su rigidez podría ser un factor que favorece el retraso de los estudiantes en egresar. De los resultados obtenidos, se concluye que, si bien el régimen es lo suficientemente flexible en cuanto a la aprobación de las asignaturas, no lo es en igual medida en lo que respecta al cursado y regularización de las mismas.

Errores en la identificación de números reales cometidos por ingresantes universitarios

En este trabajo se realiza un análisis estadístico descriptivo de los errores cometidos por ingresantes a las carreras Ingeniería Eléctrica, Ingeniería en Agrimensura, Ingeniería en Electrónica, Licenciatura en Ciencias Físicas y Licenciatura en Ciencias Químicas al identificar números reales como tales o como elementos de los conjuntos de números naturales, enteros, racionales e irracionales. Se pudo observar elevados porcentajes de errores que dan cuenta de las dificultades de los estudiantes para identificar al 0 como un número racional, entero y no natural, como racionales a aquellos números racionales con infinitas cifras periódicas y como número complejo no real a la raíz cuadrada de un número real negativo. Puede concluirse que los errores cometidos están vinculados a concepciones alternativas de los estudiantes las cuales provienen de hábitos escolares habituales a lo largo de la escolaridad preuniversitaria.

Constitutive gene expression profile segregates toxicity in locally advanced breast cancer patients treated with high-dose hyperfractionated radical radiotherapy

Breast cancer patients show a wide variation in normal tissue reactions after radiotherapy. The individual sensitivity to x-rays limits the efficiency of the therapy. Prediction of individual sensitivity to radiotherapy could help to select the radiation protocol and to improve treatment results. The aim of this study was to assess the relationship between gene expression profiles of ex vivo un-irradiated and irradiated lymphocytes and the development of toxicity due to high-dose hyperfractionated radiotherapy in patients with locally advanced breast cancer. Raw data from microarray experiments were uploaded to the Gene Expression Omnibus Database (GEO accession GSE15341). We obtained a small group of 81 genes significantly regulated by radiotherapy, lumped in 50 relevant pathways. Using ANOVA and t-test statistical tools we found 20 and 26 constitutive genes (0 Gy) that segregate patients with and without acute and late toxicity, respectively. Non-supervised hierarchical clustering was used for the visualization of results. Six and 9 pathways were significantly regulated respectively. Concerning to irradiated lymphocytes (2 Gy), we founded 29 genes that separate patients with acute toxicity and without it. Those genes were gathered in 4 significant pathways. We could not identify a set of genes that segregates patients with and without late toxicity. In conclusion, we have found an association between the constitutive gene expression profile of peripheral blood lymphocytes and the development of acute and late toxicity in consecutive, unselected patients. These observations suggest the possibility of predicting normal tissue response to irradiation in high-dose non-conventional radiation therapy regimens. Prospective studies with higher number of patients are needed to validate these preliminary results

Combined low initial DNA damage and high radiation-induced apoptosis confers clinical resistance to long-term toxicity in breast cancer patients treated with high-dose radiotherapy

Journal Article; Research Support, Non-U.S. Gov't;BACKGROUND. Either higher levels of initial DNA damage or lower levels of radiation-induced apoptosis in peripheral blood lymphocytes have been associated to increased risk for develop late radiation-induced toxicity. It has been recently published that these two predictive tests are inversely related. The aim of the present study was to investigate the combined role of both tests in relation to clinical radiation-induced toxicity in a set of breast cancer patients treated with high dose hyperfractionated radical radiotherapy. METHODS. Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma treated with high-dose hyperfractioned radical radiotherapy. Acute and late cutaneous and subcutaneous toxicity was evaluated using the Radiation Therapy Oncology Group morbidity scoring schema. The mean follow-up of survivors (n = 13) was 197.23 months. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp). Radiation-induced apoptosis (RIA) at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. RESULTS. Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46). Radiation-induced apoptosis increased with radiation dose (median 12.36, 17.79 and 24.83 for 1, 2, and 8 Gy respectively). We observed that those "expected resistant patients" (DSB values lower than 1.78 DSB/Gy per 200 Mbp and RIA values over 9.58, 14.40 or 24.83 for 1, 2 and 8 Gy respectively) were at low risk of suffer severe subcutaneous late toxicity (HR 0.223, 95%CI 0.073-0.678, P = 0.008; HR 0.206, 95%CI 0.063-0.677, P = 0.009; HR 0.239, 95%CI 0.062-0.929, P = 0.039, for RIA at 1, 2 and 8 Gy respectively) in multivariate analysis. CONCLUSIONS. A radiation-resistant profile is proposed, where those patients who presented lower levels of initial DNA damage and higher levels of radiation induced apoptosis were at low risk of suffer severe subcutaneous late toxicity after clinical treatment at high radiation doses in our series. However, due to the small sample size, other prospective studies with higher number of patients are needed to validate these results.This work was subsidized by a grant from the Ministerio de Educación y Ciencia (CICYT: SAF 2004-00889) and Fundación del Instituto Canario de Investigación del Cáncer (FICIC).Yes2011-0