Procesos de comunicación en la modelación matemática escolar

RESUMEN: Se presentan los avances de una investigación que analiza las dimensiones de la comunicología (expresión, difusión, interacción, estructuración y observación) y los procesos de comunicación de la teoría de sistemas de Niklas Luhmann (autorreferencialidad, autopoiesis e interpenetración) que se involucran en actividades de modelación matemática. La investigación se desarrolla bajo un enfoque cualitativo a partir de un estudio de caso en el que participan seis estudiantes de grado noveno (13-15 años). Los datos se vienen obteniendo a través grabaciones de audio y video además de documentos escritos producidos por los participantes. La investigación permite observar la comunicación como un sistema autopoiético, que se genera a través de distinciones que conllevan por medio de la toma de decisiones a la acción y de nuevo a la comunicación

Caracterización de los Sistemas Ganaderos de Aptitud Lechera en el Valle del Quijos, Provincia del Napo, Ecuador

This paper focuses on identifying and characterizing the structure, function, as well as the use of technology of the livestock systems on the spatial, socioeconomic, and environmental dynamics in which livestock is developed in the Quijos Valley (Ecuador). The methodology was based on bibliographic exploration and fieldwork through observation and surveys applied in 70 farms in the region. As a result of the statistical analysis, the existence of four livestock typologies was characterized; G1 without the use of technology, G2 little use of technology, G3 semi-technified, G4 technified. In the first three (93.17% of the total), the forest component covers a very high percentage in relation to the size of the farms. In these groups, it shows silvopastoral systems (SSP) in high densities of trees per hectare under spatial arrangementssuch as live fences and scattered paddocks. We also have several bovine biotypes. For the first livestock typologies G1, G2 and G3, mestizo breed animals (Brown Swiss, Holstein, Norman) predominate with dual purpose productive orientation (meat and milk). The composition of the herd shows an atypical distribution in the first two typologies. This is because there is no balance according to each bovine category, thus having a significant effect on productivity. Meanwhile in the group of high use of technology, there are bovine animals of pure milk production or crosses (Jersey, Holstein). It is concluded that there is a wide divergence between the livestock systems identified and characterized in the Quijos Valley. Thus, the measure gained in intensification has been lost in conservation.Este trabajo permitió identificar y caracterizar la estructura, función, así como el uso de tecnología de los sistemas ganaderos, sobre las dinámicas espaciales, socioeconómicas y ambientales en las cuales se desarrolla la ganadería en el Valle del Quijos (Ecuador). La metodología se basó en la exploración bibliográfica y el trabajo de campo por medio de observación y encuestas aplicadas en 70 fincas de la región. Como resultado del análisis estadístico, se caracterizó la existencia de cuatro tipologías ganaderas; G1 sin uso de tecnología, G2 poco uso de tecnología, G3 semitecnificadas, G4 tecnificadas. En las tres primeras (93.17 % del total), el componente boscoso cubre un porcentaje muy alto en relación con el tamaño de las fincas, encontrando en estos grupossistemassilvopastoriles(SSP) en altas densidades de árboles por hectárea bajo arreglos espaciales como cercas vivas y dispersos en potreros. Igualmente tenemos varios biotipos bovinos, en donde para las primeras tipologías ganaderas G1, G2 y G3, predominan animales mestizos de razas (Brown Swiss, Holstein, Normando) con orientación productiva doble propósito (carne y leche); la composición del hato muestra una distribución atípica en las dos primeras tipologías, al no existir equilibrio de acuerdo con cada categoría bovina, afectando así la productividad. Mientras tanto en el grupo de alto uso de tecnología, se tienen bovinos de razas de producción de leche puras o en cruces (Jersey, Holstein). Se concluye que existe una amplia divergencia entre los sistemas ganaderos identificados y caracterizados en el Valle del Quijos y que, a medida que se ha ganado en intensificación, se ha perdido en conservación

PRESENCIA DE KLEBSIELLA PNEUMONIAE CARBAPENEMASA (KPC) Y BETALACTAMASA DE ESPECTRO EXTENDIDO (BLEE) EN PACIENTES HOSPITALIZADOS. UNA ACTUALIZACIÓN

Introducción: La enterobacteria Klebsiella pneumoniae es un bacilo gram negativo, agente causal de infecciones intrahospitalarias de difícil tratamiento, es la responsable de un gran número de afecciones las cuales pueden infectar desde: el tracto urinario, respiratorio, órganos intraabdominales hasta producir casos de bacteriemia.  Objetivo: Analizar evidencias científicas actualizadas sobre Klebsiella pneumoniae productora de carbapenemasa (KPC) y betalactamasa de espectro extendido (BLEE) en pacientes hospitalizados. Métodos: El estudio es de diseño documental de tipo descriptivo, de nivel explicativo, se hizo la búsqueda de 98 artículos relacionados al tema, por medio de buscadores científicos como Pudmed, Scielo, Scopus, Web of Science, Elsevier, publicado en los últimos diez años, de los cuales se tomaron solo 10 ya que cumplían los criterios de inclusión. Resultados: Existe un predominio de casos de Klebsiella Pneumoniae en Colombia 91%, Argentina con 83% y Cuba 80,30%, la resistencia se ha asociado con más frecuencia al uso de cefalotina, cefuroxima, ceftriaxona, sobre todo en Paraguay y Argentina. Conclusión: la presencia de la K. pneumoniae y su resistencia antimicrobiana es un problema creciente a nivel de salud pública, que ha ganado mayor protagonismo con el pasar de los años.   Palabras clave: Bacteriemia, Enterobacteriaceae produtoras de carbapenemase, Cefalotina, Ceftriaxona, Cefuroxima   ABSTRACT   Introduction: The enterobacterium Klebsiella pneumoniae is a gram-negative bacillus, the causative agent of difficult-to-treat intrahospital infections, it is responsible for a large number of conditions which can infect from: the urinary tract, respiratory tract, intra-abdominal organs to produce cases of bacteremia. Objective: To analyze updated scientific evidence on Klebsiella pneumoniae that produces carbapenemase (KPC) and extended-spectrum beta-lactamase (ESBL) in hospitalized patients. Methods: The study is of a documentary design of a descriptive type, of an explanatory level, a search was made for 98 articles related to the subject, through scientific search engines such as Pudmed, Scielo, Scopus, Web of Science, Elsevier, published in the last ten years, of which only 10 were taken as they met the inclusion criteria. Results: There is a predominance of Klebsiella pneumoniae cases in Colombia 91%, Argentina 83% and Cuba 80.30%, resistance has been more frequently associated with the use of cephalothin, cefuroxime, ceftriaxone, especially in Paraguay and Argentina. Conclusion: the presence of K. pneumoniae and its antimicrobial resistance is a growing public health problem, which has gained greater prominence over the years.   Keywords: Bacteremia, Carbapenem-Resistant Enterobacteriacea, Cephalothin, Ceftriaxone, Cefuroxime

Influence of Litter Size at Birth on Productive Parameters in Guinea Pigs

A study was conducted at the Escuela Superior Politècnica de Chimborazo, Ecuador, to evaluate the influence of litter size of guinea pigs (Cavia porcellus) on their development and to establish the economic profitability of the production system. Forty-eight animals were used, distributed into litters of two, three, and four rodents per litter, with a balanced diet and green fresh alfalfa for the weaning, growth, and fattening stage, the rodents and litters were randomly selected, applying the statistical model completely randomly and evaluating different variables across 120 days. The litters of three guinea pigs obtained the best productive responses and economic profitability. With respect to sex, the males presented better productive behavior, greater economic increase, and less cost, evidencing that mixed feeding influences the number of guinea pigs per birth in terms of growth and development. The results serve to improve guinea pig meat production for the rural population

Assessment of Guinea Grass Panicum maximum under Silvopastoral Systems in Combination with Two Management Systems in Orellana Province, Ecuador

Climate change has increased the interannual and seasonal variation in the average temperature and precipitation rate, which determine forage availability globally. Similar patterns of change have occurred in tropical regions, and Ecuador is no exception. This region includes other influencing factors, such as the conversion of tropical forests to extensive pastures. Therefore, this study was carried out to evaluate guinea grass (Panicum maximum) cultivated under silvopastoral systems with different management strategies in both of the seasons of the study region in Ecuador (rainy season and dry season). A randomized complete block design was used for the experiment, with three repetitions and three treatments. Agronomic measures, forage production, chemical composition, animal responses, and soil properties were evaluated. Data were analyzed with the Mixed model of SAS. Differences in all evaluated parameters were observed between treatments, and silvopastoral systems (SPSs) produced better results than conventional grass monoculture. Furthermore, there was a strong seasonal effect on forage production, chemical composition, and soil properties. Therefore, management of Panicum maximum with well-planned grazing can enhance animal responses and help to retain natural resources, lowering the pressure on forests

Origin and endpoint of the olfactory nerve fibers: as described by Santiago Ramón y Cajal

In the late Nineteenth Century, Santiago Ramón y Cajal was able to reproduce an exceptional illustration of the Olfactory Nerve pathway and its myriad of cells, by using the Golgi Method. Dr. Cajal focused intense study on the histology of the nervous system and published a treatise on the olfactory nerve fibers and the distinct peripheral origin and central nervous system endpoint of this unique pathway. The original title of this work is "Origen y terminación de las fibras nerviosas olfatorias" published in 1890. As the original publication is in Spanish, here we provide an English translation allowing present-day English speakers to read these writings. Cajal followed the trajectory of the olfactory nerve fibers as they transitioned between the peripheral and central nervous system and was able to assert that these fibers were not continuous from the olfactory bulb to the bipolar cells that relinquish into the olfactory epithelium, but that the olfactory system was made up of various cell types each having distinct morphologies and functions. This may very well be the first definitive description of the olfactory receptor neurons and the first illustrations of the continuity of these cells throughout the olfactory pathway. These meticulous histological preparations were created by first using Camillo Golgi's potassium dichromate and silver nitrate impregnation method known as "reazione nera" or "black reaction," where nerve cells, nerve fibers, and neuroglia could be visualized. This study exhibits the structural and functional organization of the mammalian fila olfactoria as it was investigated in centuries past

Regarding several points of doubt of the structure of the olfactory bulb: as described by T. Blanes

In order to complement the studies on the fila olfactoria completed by Dr. Santiago Ramón y Cajal, we have included a translation of "Sobre Algunos Puntos Dudosos de la Estructura del Bulbo Olfatorio" by T. Blanes, a student of Dr. Cajal. This work describes in stunning detail additional morphological aspects of the olfactory pathway, including what was at the time the modestly studied neuroglia. The neuroglia of the olfactory system has been revisited in the last several decades for its importance in the field of regenerative neuroscience. Olfactory ensheathing glia has the unique quality of providing ensheathment to neurons which traverse from the central to the peripheral nervous system and are being used as a candidate in present-day transplantation studies to mimic this phenomenon at the dorsal root entry zone after a central nervous system injury. Although this fine work has passed its centennial anniversary since initial publication, it has been widely cited throughout the years, and of recent when Pressler and Stowbridge reported Blanes cell electrophysiological recordings (Neuron V 49, 6; p 889-904, 2006). An English translation the details of what Blanes initially documented with unduplicated precision can now be made available to a wider audience in the field of neuroscience, and is especially important now that more and more present-day studies require a precise and complete understanding of the anatomical structures contained within the olfactory system

Hábitat popular sustentable en San Juan de Pasto mejoramiento integral, diseño urbano y una transformacion a la visión de la vivienda económica.

El presente trabajo pretende sentar las bases para desarrollar desde un nuevo concepto hasta un nuevo prototipo de vivienda económica, basado sobre conceptos de sustentabilidad, se busca además satisfacer las necesidades básicas de vivienda en la ciudad de san Juan de pasto además de aprovechar las grandes posibilidades y potencialidades. Son alarmantes las condiciones de la vivienda de interés social (VIS) en la ciudad de San Juan de Pasto, las políticas no han dado una verdadera solución al problema, y al déficit presentado en el municipio, mientras esto ocurre, la población aumenta considerablemente, mas aun dentro de los estratos 1 y 2, directos afectados en la realización de este tipo de proyectos. El proyecto busca poner en valor los activos vinculados a la vivienda en el barrio, tanto para la subsistencia material como para la integración social, con el propósito de mejorar la calidad de vida, además de explorar en nuestra ciudad la solución de una vivienda digna de características mínimas. Partiendo de la necesidad de la población y la explosión demográfica presentada en la ciudad, con base en esta realidad el proyecto plantea mejorar la definición del concepto de vivienda de interés social a un hábitat popular sustentable, entendida como el desarrollo de actividades sociales, culturales, y económicoproductivas de bienes y servicios en un mismo ámbito, y así orientar el desarrollo urbano del proyecto a que se consolide como un vínculo de integración social y cultural con el trabajo incorporado al territorio. Para obtener como resultado un planteamiento urbano y arquitectónico amarrado a elementos urbanos estructurantes que permitan el desarrollo de un sistema sustentable, a partir de la propuesta de incorporar el suelo productivo en las viviendas de manera comunal, para la integración de todos los aspectos sociales y culturales de una comunidad

Large-Scale Cryosectioning Technique Allows in Vitro Correlation of Magnetic Resonance Imaging and Gross Histologic Findings in the Wrist

To enhance the usefulness of magnetic resonance imaging (MRI) in the clinical assessment of wrist joint pathology, we correlated findings from consecutive MRIs of cadaver wrists with findings from gross histologic sections of these wrists, using the sections as the standard of reference. The study required a sectioning technique that allowed preparation of large-scale sections closely matching corresponding MRIs in size and sectioning plane. We adapted a large-scale cryosectioning technique for undecalcified bone, previously described in the literature, to our study of 16 formalin fixed cadaver wrists. After subjecting each wrist to MR imaging with a wrist coil, we cryosectioned the entire wrist joint, from the distal ulna and radius to the proximal metacarpals, in the frontal plane, which corresponded to the MR images. The cryostat's tissue stage was mounted on a ball and socket-like joint that allowed corrections of the sectioning plane, enabling us to obtain sections in a plane closely resembling the corresponding MRIs. We stained the cryosections by a safranin-O fast green method modified to minimize hydration. When cryosections whose portions detached from the slide during staining were eliminated, morphologic comparison of the remaining coverslipped sections with photos of the corresponding tissue block surface taken before sectioning revealed that the sections were accurate representations of the wrist. The sections were deemed suitable as a standard of reference for comparison of the corresponding MRIs. The large-scale sectioning technique and modified staining method can be used in further comparison studies aimed at refining MRI techniques to permit greater differentiation of joint structures on the MRI. (The J Histotechnol. 21:225-229, 1998