Presentación: Avances recientes sobre el liderazgo escolar en países anglófonos

Los estudios sobre el liderazgo escolar están teniendo un desarrollo creciente en los últimos años. El interés por comprender y analizar sus características, estilos, procesos y efectos ha movilizado a numerosos especialistas y grupos de investigación en países y contextos diferentes. Animados por esa inquietud, los autores de este artículo, de las Universidades de Barcelona, Autónoma de Barcelona y de California, nos propusimos compartir conocimientos y profundizar en su estudio durante el período sabático del profesor Charles Slater en la Universidad de Barcelona en el curso 2012-2013

Towards social justice in highly complex schools in Catalonia, Spain

This study investigated social justice from the point of view of school directors, teachers, and parents. We chose two schools that were undergoing major demographic changes because of increased immigration into Catalonia, Spain. They were both classified as "schools of maximum complexity" because of their socio-economic characteristics. The research questions focused on how directors, teachers, and parents give meaning to social justice and what actions they take to achieve it. Teachers and principals adopted practices that have been described in leadership literature as transformational, such as building trust and challenging the process; they only occasionally showed transformative practices like those described by Santamaria (2014) as applied critical leadership (ACL). They were motivated by seeing the needs of migrant families and students with special needs. They seriously considered social cohesion and believed that all students should be given the same opportunities and treated fairly. While these principals wanted to guide teachers to see their work in new ways and develop practices to address the needs of a changing student population, they did not reflect on the connection between day-to-day problems and the larger social system. This critical perspective is essential to ACL

Diversidad ortopterológica de la Reserva Territorial Sureste de la Ciudad Universitaria (UNAM)

El crecimiento constante de la población humana hace que la mancha urbana extienda sus límites hacia las reservas ecológicasreduciendo el tamaño de éstas, generando importantes efectos deborde que acentúan la fragmentación del paisaje y que potencializan la pérdida de continuidad de la cubierta vegetal.Las reservas ecológicas, así como las áreas verdes urbanas (representadaspor parques y jardines) son hábitats relictuales para una grandiversidad de especies que sobreviven dentro de la matriz urbana. La Reserva Ecológica del Pedregal de San Ángel de Ciudad Universitaria (REPSA-CU) es la más importante en el suroeste del Distrito Federal debido a que abarca 237.3 hectáreas y en ella se conservan 377 especies de plantas vasculares, 180 especies de vertebrados nativos y por lo menos 817 especies de artrópodos, de las cuales 26 son ortópteros con una importante posición dentro de la cadena trófica y son determinantes del funcionamiento del ecosistema. Los objetivos de este trabajo fueron: 1. Conocer las especies de ortópteros presentes en la Reserva Territorial Sureste de la Ciudad Universitaria de la Universidad Nacional Autónoma de México (RTSE), mediante la elaboración de un inventario biológico; 2. Comparar los atributos de la comunidad ortopterológica (abundancia, diversidad; así como la densidad de individuos) que habitan en la RTSE en relación con los ortópteros de la Zona Núcleo Suroriente (ZNSO) de la REPSACU y finalmente, 3. Discutir sobre el valor ambiental de la RTSE como Zona de Amortiguamiento Ambiental para la REPSA-CU. La abundancia relativa por especie no varió significativamente entre la RTSE y la zona núcleo revisada. En la RTSE se encontraron cinco especies de ortópteros, la especie que registró mayor abundancia fue Sphenarium purpurascens purpurascens Charpentier, 1842 (Pyrgomorphidae) seguida en orden de importancia por Phoetaliotes nebrascensis (Thomas, 1872) (Acrididae). Destaca la presencia de Conocephalus (Xiphidion) ictus (Scudder, 1875) (Tettigoniidae) como un nuevo registro taxonómico para la zona. Se discute que la RTSE difiere en cuanto a diversidad ortopterológica con la ZNSO de la REPSA-CU y argumentamos su importancia para la conservación de vida silvestre; así como la importancia que poseen los ortópteros de acuerdo con su posición en la cadena trófica para el funcionamiento del ecosistema.

Structural and magnetic characterization of oleic acid and oleylamine-capped gold nanoparticles

In this work the study of oleic acid and oleylamine-capped gold nanoparticles is presented. The structural characterization of the sample shows 6.7 nm gold nanoparticles with a narrow size distribution. The experimental optical absorption spectrum has a maximum at 2.35 eV. The calculated optical absorption spectrum is shifted and narrower than the experimental one, indicating that the oleic acid and oleylamine do not merely passivate the metallic nanoparticles but modify its electronic structure. These gold nanoparticles show in addition a kind of magnetic order similar to other organic passivated gold nanoparticles as thiol-capped gold nanoparticles. Although the magnetic interactions seem to be weaker than in thiol-capped ones, the magnetic behavior looks similar to that, i.e., an invariant temperature dependence of the magnetization from 5 to 300 K and a noticeable coercive field. We analyze the influence of the organic layer bonding the nanoparticles on the magnetic behavior. © 2006 American Institute of Physics.Financial support from the Spanish MCyT under Project No. MAT2002–04246-c05–05 and CAM under Project No. S-0505/MAT/0194 are acknowledged.Peer Reviewe

Habitat association of Orthoptera in El Cimatario National Park, Querétaro, México

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Caracterización arqueomética de azulejos sevillanos

El estudio e investigación que se presenta se corresponde a una caracteriza ción realizada sobre piezas cerámicas vidriadas que, procedentes de distintos edi ficios de Sevilla, se encuentran almacenadas en la actualidad, en los Reales Al cázares de Sevilla. La metodología seguida ha consistido en el estudio de propiedades físicas determinantes del estado de conservación, análisis químico y mineralógico de las pastas y estudio por microscopía electrónica de las caracte rísticas de los vidriados e interfases. El estudio ha permitido establecer diferen cias de acuerdo con la época de fabricación, así como con relación a la conser vación de las piezas

Gendered medicinal plant knowledge contributions to adaptive capacity and health sovereignty in Amazonia

Local medical systems are key elements of social-ecological systems as they provide culturally appropriate and locally accessible health care options, especially for populations with scarce access to biomedicine. The adaptive capacity of local medical systems generally rests on two pillars: species diversity and a robust local knowledge system, both threatened by local and global environmental change. We first present a conceptual framework to guide the assessment of knowledge diversity and redundancy in local medicinal knowledge systems through a gender lens. Then, we apply this conceptual framework to our research on the local medicinal plant knowledge of the Tsimane’ Amerindians. Our results suggest that Tsimane’ medicinal plant knowledge is gendered and that the frequency of reported ailments and the redundancy of knowledge used to treat them are positively associated. We discuss the implications of knowledge diversity and redundancy for local knowledge systems’ adaptive capacity, resilience, and health sovereignty.Peer reviewe

Women becoming social justice leaders with an inclusive view in Costa Rica, Mexico and Spain

This study looks at three female school directors in Costa Rica, Mexico, and Spain who worked under challenging conditions to establish social justice. We were particularly interest in how they learned to become social justice leaders. Qualitative interviews were used to hear directly from the school directors about their experiences. Transcripts were analyzed for common themes. The commitment of these directors to social justice came from early family experiences that gave them strength and core values. They met adversity in young adulthood which reinforced their commitment to inclusive leadership

Effects of land use on water quality and Ceriodaphnia dubia reproduction

This study evaluated the effect of water quality of streams from micro-watersheds with different land use (cloud forest, coffee plantation, pasture and under urban influence) during the dry and rainy seasons, lying within the upper watershed of the La Antigua river in Veracruz, Mexico. Water characteristics were measured and laboratory subchronic toxicity tests were performed to evaluate average accumulated progeny, broods per female, and non-reproductive females of Ceriodaphnia dubia. The cloud forest contained chemically undisturbed streams, while the lowest levels of chemical alteration were detected in pasture streams: low fecundity of C. dubia was observed in both types of streams. The most disturbed streams were those associated with coffee plantations and under urban influence, which resulted in enhanced C. dubia fecundity; however, the highest chemical disturbance, found in a stream with urban influence, led to reproduction suppression in the dry season. The most favorable conditions for reproduction were provided by nutrient and probably organic enrichment in streams associated with urban environments and coffee plantations, while in cloud forest and pasture streams, the natural, and close to natural water chemistry caused a reduction in fecundity. Female fecundity was higher during the rainy season

On the leakage-power modeling for optimal server operation

Leakage power consumption is a com- ponent of the total power consumption in data cen- ters that is not traditionally considered in the set- point temperature of the room. However, the effect of this power component, increased with temperature, can determine the savings associated with the careful management of the cooling system, as well as the re- liability of the system. The work presented in this paper detects the need of addressing leakage power in order to achieve substantial savings in the energy consumption of servers. In particular, our work shows that, by a careful detection and management of two working regions (low and high impact of thermal- dependent leakage), energy consumption of the data- center can be optimized by a reduction of the cooling budget