Creacion en SAP del sistema de lubricacion para equipos mecanicos de planta Nueva Aldea-Celco S.A.

68 p.Celulosa Arauco y Constitución, Planta Nueva Aldea, es la planta mas moderna de Sudamérica en su producción de celulosa. Ahora que esta en pleno funcionamiento, se empezó a confeccionar el Sistema de Mantención, el cual incluye : Mantenciones Mayores a Equipos, Rutas de Inspección y el Sistema de Lubricación. Por ello, mi intención es de Implementar el Sistema de Lubricación en SAP, ya que al no tener controlado esta rama de la Mantención, tendríamos el aumento de la Energía para el funcionamiento de los equipos y a la larga la posible falla de estos, los que implicarían un alto costo en la producción. Para poder empezar a enhebrar este Sistema, se debería realizar un Levantamiento General de todos los Equipos que se encuentran instalados y funcionando, para luego empezar a generar los Planes Preventivos de Lubricación; y por ultimo su Programación, para así empezar a generar las Ordenes de Trabajo y también Indicadores de Control a las tareas respectivas

Structural and Functional Aberrations in the Cerebral Cortex of Tenascin-C Deficient Mice

The extracellular matrix glycoprotein tenascin-C (TNC) has been implicated in neural development and plasticity but many of its functions in vivo remain obscure. Here we addressed the question as to whether the constitutive absence of TNC in mice affects cortical physiology and structure. Defined major cell populations (neurons and inhibitory neuronal subpopulations, astrocytes, oligodendrocytes and microglia) were quantified in the somatosensory and motor cortices of adult TNC deficient (TNC−/−) and wild-type (TNC+/+) mice by immunofluorescence labelling and stereology. In both areas studied we found abnormally high neuronal density, astrogliosis, low density of parvalbumin-positive interneurons and reduced ratios of oligodendrocytes to neurons and of inhibitory to excitatory neurons in the TNC deficient as opposed to the non-deficient animals. Analysis of Golgi-impregnated layer V pyramidal neurons in TNC−/− animals showed aberrant dendrite tortuosity and redistribution of stubby spines within first- to third-order dendritic arbors. Significantly enhanced responses upon whisker stimulation were recorded epicranially over the barrel and the motor cortices of TNC−/− as compared to TNC+/+ animals, and this effect might be associated with the diminished inhibitory circuitry. These results indicate that TNC is essential for normal cortical development and functio

Costos operacionales y margen bruto de maíz y trigo: análisis a nivel de zonas agroecológicas en la Región del Maule

46 p.El trigo y maíz, son cereales de importancia a nivel regional y nacional; la literatura generalmente compara la relación existente entre la producción y consumo, y aunque Chile debe recurrir a importaciones cada año, la capacidad de abastecimiento y su competitividad no son aspectos completamente estudiados. La información actualizada acerca de los Costos Variables (CV) y Margen Bruto (MB) para trigo y maíz en el país, y particularmente en la Región del Maule es escasa; y la incidencia que podrían tener variables socioeconómicas de los productores (edad, nivel educacional, superficie cultivada y experiencia agrícola) en los CV y MB para diferentes zonas agroecológicas no está completamente descrita en la literatura disponible. En este estudio se estimaron los CV y los MB de producciones de trigo y maíz en cuatro zonas agroecológicas de la Región del Maule. Posteriormente, se compararon estos valores entre agricultores considerando la zona y se analizó la relación existente con algunas variables socioeconómicas. Para lo anterior, se aplicó una encuesta productiva completando un total de 52 observaciones de producción de maíz y 160 de producción de trigo, distribuidas en cuatro zonas agroecológicas de la Región del Maule: Pencahue, Cauquenes, San Clemente y Parral. Se registraron los costos de insumos por hectárea (semillas, pesticidas y fertilizantes), mano de obra y maquinaria (propia y contratada), de esta manera, se estimaron los CV y MB. Se aplicaron análisis de varianzas (ANOVA) para evaluar la incidencia de las variables socioeconómicas en los CV y MB. En ambos cultivos, la fertilización y uso de maquinaria, tienen la mayor participación dentro de los CV, mientras que, la menor corresponde a los pesticidas. En trigo, en las cuatro zonas hubo productores con MB negativos, acentuándose esta situación en la comuna de Cauquenes. La superficie cultivada y la educación mostraron diferencias significativas en el CV. Para el maíz, todas las zonas presentaron al menos un MB negativo, a excepción de Parral; esta zona inclusive presentó el mayor MB a nivel regional. La superficie, edad y experiencia agrícola fueron significativas para el MB; en tanto, para el CV solamente la edad. Cauquenes (secano sin riego) mostró una producción de maíz a pequeña escala, con los valores de CV y MB más bajos. Parral (valle central con riego) obtuvo el mayor MB de la Región, se verificó que productores jóvenes incurren en CV más altos, además, son capaces de acceder a MB más altos. En trigo, el MB promedio de la zona de Cauquenes fue significativamente menor que las demás zonas bajo estudio. La superficie cultivada y la educación se relacionaron positivamente con CV y MB. De los resultados se desprende, que a nivel regional se debe avanzar en la eficiencia respecto al uso de los insumos, además, los productores deben considerar el valor de mano de obra propia o familiar y uso maquinaria propia en sus costos, que en varios casos incide en valores de MB negativos.Palabras claves: margen bruto, trigo, maíz, variables socioeconómicas./ABSTRACT: Wheat and maize are grains of regional and national importance. Chile is an import country of these crops and usually the import requirements reach 50% of the internal production. Updated information about the Variable Costs (VC) and Gross Margin (GM) for wheat and corn in the country, and particularly in the Maule Region is not enough. The impact of socioeconomic aspects such as age, educational level, area cultivated and agricultural experience and agro-ecological conditions could have in the VC and GM for different is not fully described. In this study we estimated the VC and GM for wheat and maize production in four agro-ecological zones of the Maule Region. Then, we compared these values among farmers considering the area and we analyzed the relationship with socio-economic variables. A survey for a total of 52 observations of maize and 160 wheat productions was performed. Costs per hectare (seeds, pesticides and fertilizers), labor and machinery (own and hired) were described and the VC and GM were computed. Analyzes of variance (ANOVA) were applied in order to assess the impact of socioeconomic variables in the VC and GM. In both crops, fertilization and use of machinery have the highest contribution within the VC, whereas the lowest corresponds to pesticides. In wheat in the four areas were producers with negative GM, being the main place with presence of this situation the municipality of Cauquenes. Farm land and education showed significant differences in the VC. For corn, all areas showed at least one negative GM, except Parral, because this area had the highest GM regionally. Farm land, age and farming experience were significant for the GM, whereas for the VC only was age of farmers. Cauquenes (non-irrigated land) showed small scale corn production, with the lowest VC and GM values. Parral (Central Valley) shown the largest GM in the region; it was found that young producers present higher VC, moreover, are able to access to higher GM. For wheat, in Cauquenes VC was significantly lower than other areas under study. Farm land and education was positively related to VC and GM. From these results we can deduced that at the regional level we should improve the efficiency in the use of the inputs. In addition, producers must consider the value of their own work or family help and the use of their own machinery in the costs structure, which in some cases affects negative GM values. Keywords: variable costs, gross margin, wheat, maize, socioeconomic variables

Cálculo integral aplicado a las ciencias empresariales y económicas

Se describen los aspectos didácticos que caracterizan este texto. Estos se relacionan con los propósitos generales de la enseñanza y el aprendizaje del cálculo en el nivel de educación superior, tales como facilitar la comprensión y aplicación de conceptos propios del cálculo integral en contextos de las ciencias empresariales y económicas. En el libro se resaltan en particular los elementos conceptuales y procedimentales, y las ayudas pedagógicas. Este libro, denominado Cálculo integral aplicado a las ciencias empresariales y económicas, surge como una respuesta a las necesidades de estudiantes y profesores de la Facultad de Ciencias Empresariales y Económicas de la Universidad del Magdalena acerca de la formación matemática de futuros profesionales. Entre esas necesidades se encuentran las relacionadas con intervenir los problemas de deserción y mortalidad académica en el área de matemáticas y, con ello, la utilización de materiales tipo libro de texto que se enmarquen en las orientaciones institucionales y que sirvan de apoyo para el proceso de enseñanza y aprendizaje de las matemáticas. La intención de este libro es contribuir con el trabajo en el aula de clase, tanto para el profesor como para los estudiantes, y con los procesos de aprendizaje de estos últimos en su trabajo autónomo para el desarrollo de la asignatura de Cálculo Integral. El contenido de este texto se articula con asignaturas de las diferentes carreras de las ciencias empresariales y económicas que son previas y posteriores al curso de Cálculo Integral, como por ejemplo Cálculo Diferencial, Microeconomía, entre otras. Se ha procurado que la estructura del libro incluya contenidos básicos necesarios para el desarrollo de temas propios del cálculo integral, de tal manera que al lector se le facilite la comprensión y aplicación de los temas tratados

Epicranial sensory evoked potential recordings for repeated assessment of cortical functions in mice

In the present study, we describe a simple and minimally invasive method to record sensory evoked potentials (SEP) in the anesthetized mouse. The hardware includes a 16-channel acquisition system with a high signal/noise ratio and high temporal resolution. Under general anesthesia the skull is exposed and stainless steel electrodes are placed directly over the bone. A computer controlled electromechanical stimulation is applied to a single whisker or a group of whiskers unilaterally and cortical responses are recorded bilaterally. Primary SEP are detected over the contralateral barrel cortex, but delayed signals appear over the motor cortex, secondary somatosensory cortex and the ipsilateral hemisphere. The size of evoked SEP correlates with the number of stimulated whiskers and responses are reproducible and consistent over time when recorded repeatedly for up to 6 weeks. We conclude that epicranial multichannel recording of SEP represents an interesting, minimally invasive approach to monitor repeatedly cortical activity and study certain aspects of long-term plasticity of evoked responses in mice

Structural and Functional Aberrations in the Cerebral Cortex of Tenascin-C Deficient Mice

The extracellular matrix glycoprotein tenascin-C (TNC) has been implicated in neural development and plasticity but many of its functions in vivo remain obscure. Here we addressed the question as to whether the constitutive absence of TNC in mice affects cortical physiology and structure. Defined major cell populations (neurons and inhibitory neuronal subpopulations, astrocytes, oligodendrocytes and microglia) were quantified in the somatosensory and motor cortices of adult TNC deficient (TNC2/2) and wild-type (TNC1/1) mice by immunofluorescence labelling and stereology. In both areas studied we found abnormally high neuronal density, astrogliosis, low density of parvalbumin-positive interneurons and reduced ratios of oligodendrocytes to neurons and of inhibitory to excitatory neurons in the TNC deficient as opposed to the non-deficient animals. Analysis of Golgi-impregnated layer V pyramidal neurons in TNC2/2 animals showed aberrant dendrite tortuosity and redistribution of stubby spines within first- to third-order dendritic arbors. Significantly enhanced responses upon whisker stimulation were recorded epicranially over the barrel and the motor cortices of TNC2/2 as compared to TNC1/1 animals, and this effect might be associated with the diminished inhibitory circuitry. These results indicate that TNC is essential for normal cortical development and function

The role of neural cell adhesion molecules in plasticity and repair

Repair and functional recovery after brain injury critically depends on structural and functional plasticity of preserved neuronal networks. A striking feature of brain structures where tissue reorganization and plasticity occur is a strong expression of the polysialylated neural cell adhesion molecule (PSA-NCAM). An important role of this molecule in various aspects of neuronal and synaptic plasticity has been revealed by many studies. Recently, a new mechanism has been elucidated whereby PSA-NCAM may contribute to signalling mediated by the neurotrophic factor BDNF, thereby sensitizing neurons to this growth factor. This mechanism was shown to be important for activity-induced synaptic plasticity and for the survival and differentiation of cortical neurons. A cross-talk between these molecules may, thus, reveal a key factor for properties of structural plasticity and in particular could mediate the activity-dependent aspects of synaptic network remodeling. Animal models have been developed to assess the role of these molecules in functional recovery after lesions

Validation of an Abbreviated Scale of the CENVI Questionnaire to Evaluate the Perception of School Violence and Coexistence Management of Chilean Students: Differences between Pandemic and Post-Pandemic

The objective of the study was to specify an abbreviated model of the school coexistence questionnaire for non-violence (CENVI) for students from 5th to 8th grade (9 to 14 years old), in order to determine the perception of violence and management of school coexistence, and the differences between Mapuche and non-Mapuche students. A total of 1870 students from schools in the city of Temuco (Chile) responded to the CENVI questionnaire. There were two samples: (1) Pandemic, with online, face-to-face and hybrid classes; and (2) Post-pandemic, with face-to-face classes. Sample 1 consisted of 848 students aged 9 to 15 years (M = 11.90; SD = 1.27). Sample 2 consisted of 1022 students aged 9 to 14 years (M = 11.46; SD = 1.14). The questionnaire was validated using expert inter-judgment and Confirmatory Factor Analysis. A good fit of the proposed model to the data and good internal consistency measured according to the composite reliability were found, and convergent validity was demonstrated. Mapuche students perceived more physical violence and social exclusion. Cut-off points were proposed for the interpretation of the results. In the data, the effect of Coexistence Management on School Violence was null. The discussion approaches the findings from the literature on education in spaces of socio-cultural diversity in a Mapuche context

Long-term plasticity in mouse sensorimotor circuits after rhythmic whisker stimulation

Mice actively explore their environment by rhythmically sweeping their whiskers. As a consequence, neuronal activity in somatosensory pathways is modulated by the frequency of whisker movement. The potential role of rhythmic neuronal activity for the integration and consolidation of sensory signals, however, remains unexplored. Here, we show that a brief period of rhythmic whisker stimulation in anesthetized mice resulted in a frequency-specific long-lasting increase in the amplitude of somatosensory-evoked potentials in the contralateral primary somatosensory (barrel) cortex. Mapping of evoked potentials and intracortical recordings revealed that, in addition to potentiation in layers IV and II/III of the barrel cortex, rhythmic whisker stimulation induced a decrease of somatosensory-evoked responses in the supragranular layers of the motor cortex. To assess whether rhythmic sensory input-based plasticity might arise in natural settings, we exposed mice to environmental enrichment. We found that it resulted in somatosensory-evoked responses of increased amplitude, highlighting the influence of previous sensory experience in shaping sensory responses. Importantly, environmental enrichment-induced plasticity occluded further potentiation by rhythmic stimulation, indicating that both phenomena share common mechanisms. Overall, our results suggest that natural, rhythmic patterns of whisker activity can modify the cerebral processing of sensory information, providing a possible mechanism for learning during sensory perception

Ahorro de energia en el consultorio de San Javier

154 p