Matemática, informática y la “renegociación” de normas preexistentes

El deseo de dar respuestas a interrogantes tales como ¿Qué tipo de conocimientos requiere una sociedad en constante transformación?; ¿qué capacidades o estrategias debemos promover para favorecer la formación de individuos social, cultural e intelectualmente plenos, comprometidos con su entorno?. ¿Será posible contemplar en las planificaciones pedagógicas la secuencia evolutiva natural de la vida (ambiente enseñanzas- memorias-comportamiento individual-comportamiento social-enseñanzas-ambiente), los tiempos biológicos requeridos para consolidar, almacenar y dar funcionalidad a la información adquirida?; ¿imponerse a la aceleración (o inercia) de los tiempos administrativos? nos lleva a reflexionar sobre la propia práctica, considerar el rediseño de la misma, a proponernos finalmente un plan de trabajo cuya estructuración contemple tanto cuestiones atinentes a la propia disciplina como, y especialmente, a todas aquellas otras que tuvieran que ver con una positiva integración Sociedad, Ciencia y Tecnología, S/C/T. En una primer etapa procedimos a investigar, caracterizar y explicitar una serie de normas “sociomatemáticas” que llamamos preexistentes y que a nuestro juicio serían inhibidoras del aprendizaje y relativas al contexto sociocultural en el que nos movemos. Por contraposición establecimos normas a renegociar con nuestros estudiantes, las que llamamos “emergentes”. Concretada la primer etapa del plan (sistema de interpretación, diseño de instrumentos para la intervención pedagógica) generamos experiencias participativas con la presencia de estudiantes y docentes a los fines de implementar los instrumentos diseñados, observar y evaluar la calidad de los mismos, el sistema de interpretación en sí. El presente trabajo trata de algunos resultados y conclusiones obtenidas en esta segunda etapa del plan

Las funciones en la resolución de problemas

En este trabajo presentamos algunas reflexiones y una propuesta acerca de la enseñanza por resolución de problemas, siendo el eje de esta última la aplicación y discusión del concepto de Función. En las carreras ´no matemáticas´ sin relegar el papel fundamental de la formación en lo teórico-conceptual los esfuerzos se desplazan hacia la aplicación de los métodos matemáticos en la resolución de problemas de las ciencias en general. Dado que el desarrollo mismo de la ciencia puede entenderse como resultado de la búsqueda de solución a los distintos problemas que aquejan al hombre, creemos que la ´enseñanza por resolución de problemas´ coadyuva a promover el cambio conceptual y metodológico que requiere actualmente el sistema educativo en general. La propuesta consiste esencialmente en el planteo de una situación problemática familiar al estudiante para, a partir de allí y siempre bajo la guía y supervisión del docente, proceder a su discusión, al planteo de conjeturas e hipótesis, resolución, verificación, etc. En este caso el problema requiere del concepto de función, concepto básico y esencial en toda disciplina que acuda a los modelos matemáticos. Creemos que este presenta características que lo signan como concepto fuerza en la implementación del cambio pretendido; que su uso en el marco de la resolución de problemas coadyuva a tal propósito pues, entre otras bondades, las funciones se caracterizan por tener cuatro representaciones o codificaciones distintas -gráfica, numérica, analítica, verbal- cada una de las cuales expresa aspectos o propiedades didácticas no equivalentes ni equiparables entre sí, lo cual, además de ampliar el espectro de posibilidades para trabajar con el estudiante, proporciona elementos para una mejor evaluación del mismo (asimilando la comprensión del concepto a la capacidad de recodificar la información desde una representación a otra)

Performance of the reconstruction algorithms of the FIRST experiment pixel sensors vertex detector

Hadrontherapy treatments use charged particles (e.g. protons and carbon ions) to treat tumors. During a therapeutic treatment with carbon ions, the beam undergoes nuclear fragmentation processes giving rise to significant yields of secondary charged particles. An accurate prediction of these production rates is necessary to estimate precisely the dose deposited into the tumours and the surrounding healthy tissues. Nowadays, a limited set of double differential carbon fragmentation cross-section is available. Experimental data are necessary to benchmark Monte Carlo simulations for their use in hadrontherapy. The purpose of the FIRST experiment is to study nuclear fragmentation processes of ions with kinetic energy in the range from 100 to 1000 MeV/u. Tracks are reconstructed using information from a pixel silicon detector based on the CMOS technology. The performances achieved using this device for hadrontherapy purpose are discussed. For each reconstruction step (clustering, tracking and vertexing), different methods are implemented. The algorithm performances and the accuracy on reconstructed observables are evaluated on the basis of simulated and experimental data

Cannabinoid Receptor Type 1 in Parkinson's Disease : A Positron Emission Tomography Study with [F-18]FMPEP-d(2)

Background The endocannabinoid system is a widespread neuromodulatory system affecting several biological functions and processes. High densities of type 1 cannabinoid (CB1) receptors and endocannabinoids are found in basal ganglia, which makes them an interesting target group for drug development in basal ganglia disorders such as Parkinson's disease (PD). Objective The aim of this study was to investigate CB1 receptors in PD with [F-18]FMPEP-d(2) positron emission tomography (PET) and the effect of dopaminergic medication on the [F-18]FMPEP-d(2) binding. Methods The data consisted of 16 subjects with PD and 10 healthy control subjects (HCs). All participants underwent a [F-18]FMPEP-d(2) high-resolution research tomograph PET examination for the quantitative assessment of cerebral binding to CB1 receptors. To investigate the effect of dopaminergic medication on the [F-18]FMPEP-d(2) binding, 15 subjects with PD underwent [F-18]FMPEP-d(2) PET twice, both on and off antiparkinsonian medication. Results [F-18]FMPEP-d(2) distribution volume was significantly lower in the off scan compared with the on scan in basal ganglia, thalamus, hippocampus, and amygdala (P < 0.05). Distribution volume was lower in subjects with PD off than in HCs globally (P < 0.05), but not higher than in HCs in any brain region. Conclusions Subjects with PD have lower CB1 receptor availability compared with HCs. PD medication increases CB1 receptor toward normal levels. (c) 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder SocietyPeer reviewe

Development of Thiophene Compounds as Potent Chemotherapies for the Treatment of Cutaneous Leishmaniasis Caused by Leishmania major

Leishmania major (L. major) is a protozoan parasite that causes cutaneous leishmaniasis. About 12 million people are currently infected with an annual incidence of 1.3 million cases. The purpose of this study was to synthesize a small library of novel thiophene derivatives, and evaluate its parasitic activity, and potential mechanism of action (MOA). We developed a structure–activity relationship (SAR) study of the thiophene molecule 5A. Overall, eight thiophene derivatives of 5A were synthesized and purified by silica gel column chromatography. Of these eight analogs, the molecule 5D showed the highest in vitro activity against Leishmania major promastigotes (EC50 0.09 ± 0.02 µM), with an inhibition of the proliferation of intracellular amastigotes higher than 75% at only 0.63 µM and an excellent selective index. Moreover, the effect of 5D on L. major promastigotes was associated with generation of reactive oxygen species (ROS), and in silico docking studies suggested that 5D may play a role in inhibiting trypanothione reductase. In summary, the combined SAR study and the in vitro evaluation of 5A derivatives allowed the identification of the novel molecule 5D, which exhibited potent in vitro anti-leishmanial activity resulting in ROS production leading to cell death with no significant cytotoxicity towards mammalian cells

Efeitos da terapia de reposição hormonal estroprogestativa sobre o sistema de coagulação e de fibrinólise em mulheres na pós-menopausa

OBJECTIVE: To evaluate antithrombin III (AT), thrombin (Fragment 1+2 [F1+2] and thrombin-antithrombin [TAT]) generation markers, as well as other coagulation parameters, such as prothrombin time, partial activated thromboplastin time, thrombin time, fibrinogen, euglobulin lysis time, and platelet count, in postmenopausal women after hormonal therapy. STUDY DESIGN: Forty-five patients who received either 0.625 mg/day unopposed oral conjugated equine estrogen (CEE), 0.625 mg/day oral CEE plus medroxyprogesterone acetate (MP), or 50 &micro;g/day transdermal 17beta-estradiol plus MP, were included. Tests were performed before (T0) and after 3 (T3), 6 (T6) and 12 (T12) months of treatment. AT was determined by an amidolytic method, whereas F1+2 and TAT complex were measured by ELISA. RESULTS: There was a significant reduction in the AT level of patients who received oral CEE plus MP at T3. There was no AT reduction in patients taking either oral CEE alone or transdermal 17beta-estradiol plus MP. F1+2 increased in all patients, but it reached statistical significance only in patients receiving transdermal 17beta-estradiol MP at T3. CONCLUSIONS: The CEE associated with MP treatment may reduce AT levels, whereas unopposed CEE or transdermal 17beta-estradiol plus MP does not change AT. These changes might not be clinically relevant in the general population; however, hormonal replacement therapy may increase the risk of thrombosis in women with congenital or acquired thrombophilia.OBJETIVO: Avaliar os marcadores antitrombina III (AT), fragmento 1 + 2 da trombina (F1+2) e complexo trombina-antitrombina (TAT), bem como outros parâmetros da coagulação, como tempo de pró-trombina, tempo parcial de tromboplastina ativado, tempo de trombina, fibrinogênio e tempo de lise da euglobulina em mulheres na pós-menopausa após terapia hormonal. DESENHO DO ESTUDO: Foram incluídas 45 voluntárias que receberam estrogênios conjugados eqüinos (ECE) 0,625 mg/dia, isoladamente ou associado ao acetato de medroxiprogesterona (AMP) ou usaram o 17beta-estradiol (50 &micro;g/dia) transdérmico com AMP. Os exames foram realizados antes do tratamento (T0) e após três (T3), seis (T6) e doze (T12) meses após o início do tratamento. AT foi avaliada pelo método amidolítico, enquanto que o F1+2 e o complexo TAT por ELISA. RESULTADOS: Houve redução significante nos níveis de AT em pacientes que receberam ECE associado ao AMP no T3. Não houve redução na AT em mulheres que usaram ECE isoladamente ou aquelas com 17beta-estradiol transdérmico e AMP. O F1+2 aumentou em todos os grupos, mas apenas o grupo com 17beta-estradiol transdérmico e AMP apresentou diferença significante durante o T3. CONCLUSÕES: A associação de ECE e AMP pode reduzir os níveis de AT, enquanto ECE isoladamente ou 17beta-estradiol transdérmico com AMP não modificam-o acentuadamente. Essas alterações poderiam ser mais relevantes clinicamente na análise populacional. Todavia, a terapia de reposição hormonal aumentaria o risco de trombose em mulheres com trombofilia prévia congênita ou adquirida