Cancer anorexia: hypothalamic activity and its association with inflammation and appetite-regulating peptides in lung cancer

Background Energy homeostasis is mediated by the hypothalamus, whose inflammation-induced functional derangements contribute to the onset of anorexia in cancer. By using functional magnetic resonance imaging (fMRI), we determined the patterns of hypothalamic activation after oral intake in anorexic (A), non-anorexic (NA) cancer patients, and in controls (C). Methods Lung cancer patients were considered. Hypothalamic activation was recorded in A and NA patients and in C by fMRI, before (T0), immediately after (T1) the administration of an oral nutritional supplement, and after 15 min (T2). The grey of the hypothalamus and Blood Oxygen Level Dependent (BOLD) intensity were calculated and normalized for basal conditions. Interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-α, ghrelin, and leptin plasma levels were measured. A statistical parametric mapping was used. Results Thirteen lung cancer patients (7 M, 6 F; 9A, 4NA) and 2 C (1 M, 1 F) were enrolled. Controls had the lowest BOLD intensity. At all-time points, anorexic patients showed lower hypothalamic activity compared with NA (P < 0.001) (T0: 585.57 ± 55.69 vs. 667.92 ± 33.18, respectively; T1: 536.50 ± 61.70 vs. 624.49 ± 55.51, respectively; T2: 556.44 ± 58.51 vs. 615.43 ± 71.50, respectively). Anorexic patients showed greater BOLD signal reduction during T0–T1 than NA (8.5% vs. 6.80%, P < 0.001). Independently from the presence of anorexia, BOLD signals modification before and after oral challenge correlated with basal values of IL-1 and ghrelin (P < 0.001). Conclusions Hypothalamic activity in A cancer patients is reduced respect to NA and responds differently to oral challenges. This suggests a central control of appetite dysregulation during cancer anorexia, before, and after oral intake

Investigations into system and cow performance efficiency in pasture-based automatic milking systems

Although previous research has demonstrated that AMS can be successfully integrated with pasture-based systems, performance and efficiency levels observed in pasture-based AMS present greater variability and are lower in comparison to indoor AMS. Therefore, the general aim of this thesis was to identify strategies on how to improve system performance in pasture-based AMS operating with voluntary traffic. The literature review explored the current situation in regards to system and cow performance on pasture-based AMS. Gaps in knowledge and potential ways of increasing productivity were identified. The demonstrated effect that the number of cows milked per robot had a greater effect than milking frequency on robot performance (Chapter 3), together with the high degree of variability regarding individual cow performance (Chapter 2), led to developing a methodology to identify Efficient and Inefficient cows based on their combined effect of milking frequency and milk yield (Chapter 4). The hypothesis that differences in cow behaviour could explain, at least in part, the differences observed between levels of efficiency in cow performance was confirmed after a field study was conducted for that purpose (Chapter 6). A validation of a recently commercially released version of an activity and rumination monitoring system was conducted (Chapter 5) to allow differences in cow behaviour to be determined. The potential to manipulate robot utilisation at whole herd level was then explored in Chapter 7, in which the results of a field study conducted to evaluate if experienced cows could quickly adapt to a short period of voluntary-batch milking, without cow performance being affected, were summarised. In summary this thesis makes a significant contribution based on novel, original, and scientifically-generated knowledge, that together, will help to advance systems and cow performance and efficiency on pasture-based AMS in the future

Proceso social de institucionalización del conocimiento matemático escolar: un modelo de prácticas

Describimos un marco teórico-metodológico que permite analizar el proceso social de institucionalización de un conocimiento matemático, proceso a través del cual un conocimiento, concebido y desarrollado en ámbitos científicos, se convierte en un saber escolar. Lo describimos a partir de las prácticas de los actores involucrados. El mismo se desarrolla bajo la perspectiva socioepistemológica y se apoya en la teoría del análisis del discurso como acción social para estudiar el discurso matemático escolar. Presentamos cómo fue diseñado e implementado en el caso particular del concepto de límite y exploramos, a su vez, su posible aplicación a otros saberes matemáticos

La resolución de problemas en un ambiente de geometría dinámica

Se reporta aquí un minicurso en el que participaron profesores de matemática de Enseñanza Media. Trabajando en un ambiente de Geometría Dinámica se aborda la resolución de problemas que involucran distintas áreas de la matemática: geometría métrica, cálculo diferencial, geometría analítica, álgebra, y que permiten poner de manifiesto la pertinencia y relevancia –así como señalar sus peculiaridades- del ambiente dinámico en la construcción del conocimiento matemático por parte de los participantes y a su vez discutir su papel en el trabajo con estudiantes

Segregation method as possible process to beneficiate oxidized lead ores

In this investigation it has been demonstrated that the Segregation Process has merit for treating oxidized lead ores. The process comprises heating the crushed ore with salt and coal at about 750° C. to produce metallic lead attached to the carbon particles, which then is recovered by conventional flotation methods. The quantities of sodium chloride and coal required for the best segregation of lead obtained in this work was 1.0 percent of coal and 1.0 percent of salt by weight. Good segregation was obtained by using salt and coal as fine as 65 or 48 mesh. Segregation varied with the roasting temperature and time. At least 60 minutes was required for good segregation at 750° C. About 3 to 4 percent moisture was required for segregation at 750° C. Some valuable metals like silver, bismuth, precipitate along with the lead on the carbon particles. It is concluded that the process appears to have considerable merit on siliceous ores that are not amenable to conventional processing methods --Abstract, page 2

Los procesos de institucionalización del límite: un análisis socioepistemológico

Se reportan los avances de una investigación sobre los procesos de institucionalización del concepto de límite cuyo objetivo es explicar cómo y por qué vive en la actualidad este concepto en el ámbito escolar. Al momento se ha analizado su desarrollo socio-histórico al interior de la comunidad matemática y algunos aspectos del tratamiento del concepto en el ámbito educativo uruguayo: libros de texto y prácticas educativas concretas, buscando explicitar el vínculo entre ambos contextos. Este análisis se desarrolla desde la aproximación socioepistemológica, permitiendo explicar de qué elementos se nutre la construcción social del conocimiento, específicamente del concepto de límite

Demostraciones y construcciones elaboradas por estudiantes de profesorado a partir de una clasificación de cuadrilateros

Se describe y fundamenta una secuencia de actividades llevada a cabo con tres grupos de estudiantes de primer año de profesorado del Instituto de profesores ‘Artigas’ (Montevideo), en su curso regular de geometría euclidiana. El objetivo de la misma fue indagar sobre la posibilidad de construcción o justificación de inexistencia de cuadriláteros generados a partir de una clasificación de los mismos tomando como criterio la cantidad y posición de lados iguales, de ángulos iguales y de segmentos de diagonal iguales. Proponemos esta serie de actividades acorde a una modalidad de trabajo que consideramos necesaria en la formación de profesores: los estudiantes son quienes construyen conocimiento, en particular conocimiento que no puede ser encontrado usualmente en libros de texto u otras referencias. Sostenemos que con este tipo de experiencias, los estudiantes, futuros profesores de matemática, no sólo se van formando en lo que hace a su conocimiento matemático, sino también en lo que hace a su concepción de qué es ser docente y cómo ponerlo en práctica

Rescatando los poliedros de arquímedes

¿Por qué prismas y poliedros regulares tienen un rol protagónico en la matemática escolar? Los poliedros arquimedianos, ¿pueden ser relevantes para su inclusión en la matemática escolar de Educación Secundaria y Formación de profesores? En este taller proponemos reconocer y visualizar poliedros semirregulares con el uso del programa Poly Pro, descubrir y describir algunas de sus propiedades, identificar cuáles de ellos son arquimedianos, analizar las relaciones entre esta familia de poliedros y los poliedros regulares, explorar maneras de construirlos -a partir del análisis de grabados del artista renacentista W. Jamnitzer-, conjeturar acerca de la cantidad de elementos de esa familia y ensayar diferentes justificaciones. Es decir, proponemos una actividad que favorezca el tránsito entre los niveles 0, 1 y 2 propuestos por Van Hiele en el contexto de la geometría euclidiana del espacio, articulada a su vez con la forma de concebir la actividad geométrica de Kuzniak, a través de paradigmas caracterizados por el interés por resolver problemas específicos

A mathematics teacher\u27s identity study through their teaching practices in a postgraduate training course

Guided by the question “Which aspects could affect mathematics teachers’ identity, especially in the context of a postgraduate course that includes teaching practices as mathematics teacher educators?” we analyzed the transition between actual and designated mathematics teachers’ identity in a postgraduate training course. In particular, teaching practices during the course were oriented by emerging recommendations for mathematics teacher training. We concluded that the presence of an explicit intention to develop a specific practice plays a key role in the transition between actual and designated identity. In addition, the possession of methodological tools as a means for implementing renewed practices gave support and helped practitioners to plan classes promoting mathematical activity. In the process experienced by the practitioners, mentor teacher educators were clearly significant narrators because they reinforced or hinder the desire to reach the designated identity, through their coherence with practitioner’s goals or in contradiction with them respectively