El líder étnico, liderar y liderazgo. Los Yahatti, Lepin, Juan Manuel Cachul y Juan Catriel: hombres políticos en la frontera bonaerense

Desde que se asume que los encuentros entre hispanocriollos e indígenas no fueron sólo bélicos, que hubo convivencias cotidianas, intercambios y contactos armónicos, se abre la posibilidad de pensar y analizar este contacto –violento o armónico– como el contexto relacional que exteriorizó y demandó líderes o interlocutores en cada sociedad. La región de la actual provincia de Buenos Aires conocida como “frontera bonaerense”, durante mediados del siglo XVIII y la primera mitad del XIX, será el marco espacio-temporal que permitirá situar el análisis de cuatro hombres políticos: los Yahatti, Lepin, Juan Manuel Cachul y Juan Catriel. Este análisis busca aportar elementos nominadores y significativos sobre el liderazgo étnico. En consecuencia, buscamos territorializar e historizar el liderazgo étnico de estos hombres, para poder determinar si es factible hablar de transformaciones en el liderazgo y cambios de los líderes en la relación con sus seguidores a partir del acuerdo de paces establecido con las autoridades estatales. Es decir, buscamos establecer fisonomías que nos permitan construir una enunciación descriptiva y analítica sobre dichos líderes y sus estrategias de construcción y sostenimiento de autoridad.Since it is assumed that contact between Hispanic-Creole and indigenous people was not only violent, and that it included daily life coexistence, exchanges and harmonic contact, it is possible to think and analyze these aspects as the relational context that exteriorized and required new leaders or mediators from each society. The region of present Buenos Aires province known as “frontera bonaerense”, from mid-eighteenth century to the first half of the nineteenth century, will be the space-time frame to analyze four political men: the Yahatti, Lepin, Juan Manuel Cachul and Juan Catriel. This research tries to support nominative and significant elements about ethnic leadership. Therefore, we look forward to territorialize and historicize the ethnic leadership of these men in order to determinate to which extent is viable to speak about its transformations towards their followers by means of treating peace with state authorities. Taking everything into account, we try to set characters which allow us to build a descriptive and analytical enunciation about those leaders and their authority strategies

Effects of codoping in ZnO-based semimagnetic semiconductor thin films

Single doped Zn1-xMnxO, Zn1-xFexO and codoped Zn1-x-yMnxFeyO, Zn1-x-yMnxSnyO, Zn1-x-yMnxLiyO, Zn1-x-yFexAlyO thin films were grown on sapphire and glass substrate by pulsed laser deposition and RF sputtering techniques. No secondary phases was detected from XRD analysis. Among the studied oxide films single doped with Fe and codoped with (Mn,Fe) and (Fe, Al) exhibit n-type conductivity and room temperature ferromagnetic behaviour. For the films codoped with (Mn, Sn) formation of clusters including nanowire-like structures was shown from AFM analysis. Optical and magnetooptical studies suggest of Mn, Fe, Sn and Li substitution for Zn2+ ions in ZnO lattice.This research was partially supported by the Ministry of Education and Science of Ukraine

Survival of patients with spinal muscular atrophy type 1

BACKGROUND: Spinal muscular atrophy type 1 (SMA1) is a progressive disease and is usually fatal in the first year of life. METHODS: A retrospective chart review was performed of SMA1 patients and their outcomes according to the following choices: letting nature take its course (NT); tracheostomy and invasive mechanical ventilation (TV); continuous noninvasive respiratory muscle aid (NRA), including noninvasive ventilation; and mechanically assisted cough. RESULTS: Of 194 consecutively referred patients enrolled in this study (103 males, 91 females), NT, TV, and NRA were chosen for 121 (62.3%), 42 (21.7%), and 31 (16%) patients, respectively. Survival at ages 24 and 48 months was higher in TV than NRA users: 95% (95% confidence interval: 81.8%-98.8%) and 67.7% (95% confidence interval: 46.7%-82%) at age 24 months (P < .001) and 89.43% and 45% at age 48 months in the TV and NRA groups, respectively (P < .001). The choice of TV decreased from 50% (1992-1998) to 12.7% (2005-2010) (P < .005) with a nonstatistically significant increase for NT from 50% to 65%. The choice of NRA increased from 8.1% (1999-2004) to 22.7% (2005-2010) (P < .001). CONCLUSIONS: Long-term survival outcome is determined by the choice of the treatment. NRA and TV can prolong survival, with NRA showing a lower survival probability at ages 24 and 48 months. Copyright © 2013 by the American Academy of Pediatrics

Correlation between cephalometric variables and obstructive sleep apnoea severity in children.

Aim Alterations in craniofacial growth have been associated with obstructive sleep apnoea in children. The main objectives of this study were to analyse the correlation between cephalometric variables and Obstructive Apnea/Hypopnea Index (OAHI) in order to investigate if craniofacial features may influence the severity of obstructive sleep apnoea and to study the correlation between upper nasopharyngeal width and maxillomandibular skeletal discrepancy in sagittal and vertical plane. Materials and methods Study Design: Correlations between cephalometric variables and obstructive sleep apnoea/hypopnea index and between upper airways space and maxillomandibular skeletal discrepancy were investigated. Forty-seven children with obstructive sleep apnoea diagnosed by overnight sleep study (polysomnography) underwent a lateral radiograph, orthodontic and ear-nose-throat examinations. Cephalometric analysis according to Kirjavainen has been performed to define skeletal and upper airways variables. Statistics: Spearman’s correlation analysis was performed between OAHI and all cephalometric variables. Pearson’s correlation analysis was performed between cephalometric variables of upper airway space and cephalometric variables related to maxillomandibular discrepancy. Chi-square test was used to compare occlusal features with adenoidal and tonsillar hypertrophy. Kruskal-Wallis rank test was used to compare OAHI with occlusal variables and adenotonsillar hypertrophy. Results The results show a positive correlation between OAHI and maxillomandibular discrepancy measured by ANB angle (rho=0.32; p=0.023). A significant correlation was found between upper nasopharyngeal width and vertical maxillomandibular skeletal discrepancy: 1) ad1-PNS were correlated to Mandibular Plane/SellaNasion angle (r=-0.36; p=0.012), Palatal Plane/Mandibular Plane angle (r=-0.39; p=0.007), and Posterior-Anterior Facial Height % (r=0.29; p=0.045); 2) ad2-PNS was correlated to Palatal Plane/Mandibular Plane angle (r=-0.39; p=0.007). No statistically significant differences were found in non-parametric tests between OAHI and occlusal variables or adenoidal and tonsillar hypertrophy. Conclusions The present study shows a significant correlation between maxillomandibular discrepancy and the severity of OSA. Moreover, the reduction of nasopharyngeal width was correlated to maxillomandibular hyperdivergent growth pattern. These results support the presence of a correlation between sleep-disordered breathing and craniofacial features even if the cause-effect relation is still unclear. Based on these evidences, we suggest the importance of orthodontic evaluation in the management of paediatric OSA

Estrogen blocks the protective action of melatonin in a behavioral model of ethanol-induced hangover in mice

Melatonin has antioxidant and neuroprotective properties in human beings and experimental models, as well as 'anti-estrogenic' effects. Ethanol (EtOH) affects various behavioral parameters during a period known as ethanol-induced hangover. Our study evaluated the neuroprotective effect of melatonin on motor performance during ethanol hangover in male and female Swiss mice. The females were subjected to specific hormonal states: ovariectomized (OVX) and OVX estrogenized (OVX-E2). Mice received melatonin (25μg/ml) or vehicle in their drinking water for seven days and were given intraperitoneal (i.p.) injections of EtOH (3.8g/kg) or saline on the morning of the eighth day. Motor performance was evaluated by the tightrope test 6h after EtOH exposure (hangover onset). During ethanol hangover, males exhibited lower motor performance than controls (p<0.01) but pretreatment with melatonin significantly improved performance during hangover (p<0.05). In females, melatonin treatment before ethanol-induced hangover led to a better motor performance in OVX compared with intact females (p<0.01) and a lower performance in OVX-E2 compared with not-estrogenized OVX (p<0.05). Consequently, estrogen reversed the motor performance enhancement afforded by melatonin. We conclude that estrogen interferes with the protective action of melatonin on motor performance during ethanol hangover.Fil: Karadayian, A. G.. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Mc Laughlin, M. A.. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Cutrera, Rodolfo Angel. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Cinética química y analogías: un análisis de las propuestas de enseñanza

Un supuesto altamente consensuado en los procesos de enseñanza-aprendizaje en ciencias naturales radica en relacionar los conceptos y contenidos abstractos con la realidad concreta y cotidiana. Investigaciones en el ámbito de la psicología y las ciencias cognitivas, indican que apropiarse de cualquier aspecto de la realidad supone poder elaborar una “representación” del mismo, es decir, construir un modelo mental de esa realidad (Izquierdo, 1999; Dagher, 1995). El modelo está presente en nuestra vida cotidiana, científica y escolar, y facilita la comprensión y el entendimiento de los mensajes que se reciben desde los diferentes campos. En este contexto, son de especial importancia, los modelos en la Didáctica de las Ciencias y, en particular, las analogías (Dagher, 1995; Treagust, 1992). Cualquier analogía que se plantee, por muy sugerente y útil que sea, presenta relaciones comunes entre el objeto y el análogo, pero también relaciones que difieren de un fenómeno a otro. Estas ocasiones se podrían canalizar transformándolas en invitaciones a los alumnos a la reflexión y desarrollo de su espíritu crítico. A continuación mostramos los resultados de la revisión de algunos textos escolares pertenecientes al nivel Polimodal y de textos universitarios y textos escolares utilizados en la educación media (estos últimos, empleados durante las décadas del `80 y `90, previo a la implementación de la Reforma Educativa en la Pcia. de Buenos Aires.Sección Naturales.Departamento de Ciencias Exactas y Naturale

Representaciones sociales en el aula de ciencias. El lugar del alumno

Las investigaciones en didáctica de las ciencias han focalizado los estudios sobre los problemas de aprendizaje en la estructura psicológica del alumno que aprende, en la lógica de los contenidos, o en las preconcepciones de los alumnos acerca de los contenidos, no tomando en cuenta la influencia las variables sociales en la comunidad del aula. En este trabajo se propone, desde un marco socio histórico, la incorporación de las representaciones sociales de los alumnos respecto de su lugar en el aula como un elemento central para la comprensión de la dinámica del aula y para un desarrollo de estrategias meta-cognitivas en los alumnos