732 research outputs found
Farming-up coastal fish assemblages through a massive aquaculture escape event
We investigated the changes on the mean trophic level of fish assemblages across different spatiotemporal scales, before and after a massive escape event occurred off La Palma (Canary Islands), which resulted in the release of 1.5 million fish (mostly Dicentrarchus labrax) into the wild. The presence of escaped fish altered significantly the mean trophic level of fish assemblages in shallow coastal waters. This alteration was exacerbated by the massive escape. A nearby marine protected area buffered the changes in mean trophic level but exhibited the same temporal patterns as highly fished areas. Moreover, escaped fish exploited natural resources according to their total length and possibly, time since escapement. New concerns arise as a “farming up” process is detected in shallow coastal fish assemblages where marine aquaculture is established
Murcutt, Pawson, Lacaton & Vassal: Intenciones y estrategias en la fotografía del espacio doméstico
Glenn Murcutt, John Pawson y Anne Lacaton & Jean Philippe Vassal escenifican 3
concepciones diversas de la arquitectura actual. Una parte importante de su trabajo se
ha volcado hacia el ámbito doméstico, y concretamente hacia la vivienda unifamiliar.
Las casas de campo de Murcutt, de metal y madera, son respetuosas con la naturaleza
y simultáneamente vernáculas y contemporáneas gracias a la inclusión de principios
energéticos pasivos presentes en la arquitectura popular. Las viviendas de Pawson militan
en un minimalismo trascendente, preciso y despojado que resulta a la vez exclusivo, severo,
casi monacal, y se hace extensivo al diseño integral del mobiliario y otros elementos.
Lacaton & Vassal priorizan cuestiones más inmanentes, como la sostenibilidad y el
pragmatismo, mediante una construcción ligera y seca que incorpora la naturaleza al
interior, vislumbrando una cierta provisionalidad y aparente despreocupación formal que
remiten al pabellón o el campamento. La fotografía es un medio tremendamente poderoso
que permite escoger y precisar nuestra mirada para difundir la realidad, y en este caso la
arquitectura, a través de un tamiz cuidadosamente depurado. Fotografía y arquitectura
interactúan de manera simbiótica, generando construcciones visuales capaces de reforzar
las intenciones de los autores de ambas. La comunicación indagará en la íntima relación
y las interacciones existentes entre la arquitectura y la fotografía de algunas viviendas de
Murcutt, Pawson y Lacaton & Vassal con el fin de descubrir algunas intenciones y estrategias
de estos 3 estudios para, a través de las imágenes generadas o controladas por ellos
mismos, validar, reforzar y difundir internacionalmente sus diversas posiciones militantes
Theoretical analysis of the transmission phase shift of a quantum dot in the presence of Kondo correlations
We study the effects of Kondo correlations on the transmission phase shift of
a quantum dot coupled to two leads in comparison with the experimental
determinations made by Aharonov-Bohm (AB) quantum interferometry. We propose
here a theoretical interpretation of these results based on scattering theory
combined with Bethe ansatz calculations. We show that there is a factor of 2
difference between the phase of the S-matrix responsible for the shift in the
AB oscillations, and the one controlling the conductance. Quantitative
agreement is obtained with experimental results for two different values of the
coupling to the leads.Comment: 4 pages, 4 figures, accepted for publication in Physical Review
Letter
Problème du rajeunissement des sols issus de l'altération de roches volcaniques, par des éruptions récentes de cendres, aux Nouvelles-Hébrides et aux îles Canaries
Abstract. - Two soils, one from Aoba (New Hebrides), the other from Tenerife (Canarian Islands), the rejuvenation of which by a fall of volcanic ashes has been dated (by 14 C), show that, in a humid tropical or subtropical environment, the recent rejuvenation leads to pedological forms relatively less maturated than the normal soils type. In Aoba, they are one thousand years old, saturated and slighty evoluted andosols, in Tenerife appear andic brown earths that are less than 9000 years old and bury tropical paleosols. It is noteworthy in Aoba, that only one thousand years has been enough to form halloysite, whereas Aomine and Miyauchi (1963) estimated tah 8000 years have been necessary in the case of the Japanese andosols.Résumé. - Deux sols, l'un situé à Aoba (Nouvelles Hébrides), l'autre à Tenerife (Iles Canaries), dont le rajeunissement par un recouvrement de cendres volcaniques a été daté en âge absolu (par 14 C), montrent qu'en milieu tropical ou subtropical humide, le rajeunissement conduit à des formations pédologiques relativement moins évoluées que la normale. Dans le cas d'Aoba, il s'agit d'andosols saturés datant de mille ans environ ; dans celui de Tenerife, ce sont des sols bruns andiques âgés de moins de 9000 ans, recouvrant des paléosols tropicaux. Il est remarquable à Aoba, qu'un millier d'années a suffi, en milieu tropical humide pour l'apparition d'halloysite, alors qu'Aomine et Miyauchi (1963) estimaient qu'un laps de temps de 8000 ans était nécessaire dans le cas des andosols du Japon.Quantin Patrick, Fernandez-Caldas E., Guttierrez-Jerez F., Tejedor M.L., Delibrias G. Problème du rajeunissement des sols issus de l'altération de roches volcaniques par des éruptions récentes de cendres, aux Nouvelles-Hébrides et aux îles Canaries. In: Bulletin de l'Association de géographes français, N°426, 52e année, mai 1975. pp. 211-217
CAMCAT: an oil spill forecasting system for the Catalan-Balearic Sea based on the MFS products
International audienceThe Prestige oil spill crisis (2002?2003), one of the worst oil spills that affected the Atlantic Spanish coastal line, pointed out that some management tools are needed in the form of laws, regulations and technical procedures. In particular, the issues are contingency planning and prevention against marine pollution and prediction for a proper response. In that background, the Catalan local government approved the CAMCAT (2004), a Regional contingency plan against marine pollution, to be framed within the (Spanish) National Contingency Plan. The CAMCAT contemplated the implementation of a Regional Forecasting System for the North-Western Mediterranean area, intended to help Catalan Authorities during any pollution emergency. The Laboratory of Maritime Engineering (LIM/UPC) has been responsible for the implementation of this Regional CAMCAT Forecasting System that is based (nested) on existing larger Forecasting Systems/Products, and it integrates several coastal observational data. The present paper is aiming to make an overview of the several scientific and technical activities related to the implementation and validation of the CAMCAT System
A purple plaque in a patient with systemic sclerosis
We present the case of a 43-year old woman with anti-U3 ribonucleoprotein antibody-positive systemic sclerosis presenting with an enlarging purple plaque on the left upper arm. The skin was not sclerotic; however, there had been a cluster of long-standing telangiectases preceding the plaque. Histology and immunohistochemistry confirmed an angiosarcoma. There are five reported cases in the literature about angiosarcoma arising in the skin of patients with systemic sclerosis; however, to our knowledge, this is the first to have arisen from non-sclerotic skin. We would urge clinicians to adopt a high index of suspicion for atypical vascular tumours presenting in patients with systemic sclerosis
GEOLOGY AND MINERALOGY OF KAOLIN DEPOSITS AT VEREDA BARROBLANCO, OIBA TOWN (SANTANDER): CHARACTERIZATION FOR INDUSTRIAL USES
The Barroblanco (Oiba town, Santander) were characterized by geological and mineralogical studies with the purpose to define a great variety of industrial applications. In this paper also were determined the geological conditions of formation and the reserves were estimated. The kaolin deposit occur as a tabular body emplacement in the medium horizon of the La Cumbre formation and outcrops along the Cerro Negro anticline. The identified minerals by X-ray diffractometry in the seven kaoliniferous levels beside kaolinite are quartz, muscovite/illite, anatase, giibsite and amorphous material. The dertermined mineralogical and chemical properties of kaolin defining its behavior during mineral processing. The kaolin quality after mineral processing was substantially improvement and define the most appropriate use for the production of white cement and high quality ceramics.
Key words: Kaolin, Vereda Barroblanco, kaoliniferous levels, resources.
Los caolines de la Vereda Barroblanco (Municipio de Oiba, Santander) fueron caracterizados desde el punto de vista geológico y mineralógico con el propósito de definir una gama más amplia de usos de esta materia prima mineral en la industria. En este trabajo también se determina el ambiente de depositación y se cuantifican los recursos de caolín. El depósito de caolín es de forma tabular y se localiza en un nivel intermedio de la Formación Cumbre en su Segmento D y aflora a lo largo del Anticlinal de Cerro Negro. Los minerales identificados en los siete niveles caoliniferos aparte de la caolinita son cuarzo, moscovita/illita, anatasa, gibsita y amorfos. Las propiedades mineralógicas y químicas del caolín determinadas sirvieron de base para definir su comportamiento durante el beneficio mineral. La calidad del caolin luego de ser beneficiado aumenta considerablemente y permite su uso en la fabricación de cemento blanco y de cerámica de calidad.
Palabras clave: Caolín, Vereda Barroblanco, niveles caoliniferos, recursos.
 
Body image and self-esteem in children according to their nutritional status and frequency of physical activity
Indexación: Scopus; Scielo.La actividad física juega un papel importante en el desarrollo de los niños. El propósito de este estudio fue comparar según estado nutricional y frecuencia de actividad física la imagen corporal, autoestima, riesgo cardio-metabólico y rendimiento físico de niños. Se estudió 208 niños de 11,9±1,2 años de edad, 115 hombres y 93 mujeres. Quedaron divididos según frecuencia de actividad física a la semana: El Grupo 1 (n= 87) no realizan; Grupo 2 (n= 64) realizan 1 o 2 veces/semana; Grupo 3 (n= 57), realizan 3 o 4 veces/semana. Se observó que 51 niños presentaron sobrepeso y 40 de ellos obesidad. Los niños que realizan 3 o 4 veces actividad física/semana, presentaron menor preocupación por su imagen corporal y puntajes superiores en autoestima, ambas con significancia estadística (p<0,05), además reportaron menor riesgo cardio-metabólico y mejor rendimiento físico. Se concluye que los niños con mayor frecuencia de actividad física/semana, evidencian beneficios en su desarrollo integral.Physical activity plays an important role in child development. The purpose of this study was to compare body image, self-esteem, cardio-metabolic risk and physical performance of children by nutritional status and frequency of physical activity. We studied 208 children (115 men and 93 women) 11.9±1.2 years of age. Participants were divided by frequency of physical activity per week: Group 1 (n= 87) was not physically active; Group 2 (n= 64) was physically active 1 or 2 times per week; Group 3 (n= 57) was physically active 3 or 4 times a week. We observed that 51 children were overweight and 40 obese. Children who were physically active 3 or 4 times per week, were less concerned about their body image and had higher self-esteem scores (both p <0.05). These children also reported lower cardio-metabolic risk and better physical performance. We conclude that there are overall developmental benefits for children who are more physically active.http://ref.scielo.org/d2ddf
Arquitectura expuesta. Tránsitos artísticos de la representación fotográfica de la arquitectura
If we can state that certain architectural production currently finds its origin and explicit accommodation in the field of the exhibition, it is even more logical -considering the unavoidable visual culture- to assert that the images of architecture prevail autonomously over the architecture they represent, becoming independent of the strictly disciplinary and exhibited illuminated in the aura of the artistic on the walls of a museum. To explore this argument in line with the subject from the current Ra’s issue, we will review eight exhibitions, and their corresponding catalogues, held in different museums and art galleries from 1982 to 2018, and focused on exploring architectural photographic representation and its translations to and from artistic practices. We aim not just to make an exhaustive review of this reality, but to extract from its analysis a contemporary critical reading of its potentialities and interpretations.Si es un hecho que determinada producción arquitectónica encuentra hoy en día su origen y acomodo explícito en el ámbito de lo expositivo, más lógica tiene aún –en atención a la insoslayable cultura visual– confirmar que las imágenes de la arquitectura prevalezcan autónomamente frente a esa arquitectura que representan, se independicen de lo estrictamente disciplinar y se expongan empapadas en el aura de lo artístico en las paredes de un museo. Para explorar este argumento al hilo del tema del presente número de Ra, nos apoyamos en ocho exposiciones, y sus respectivos catálogos, celebradas en diferentes museos y galerías de arte entre 1982 y 2018, centradas en explorar la representación fotográfica de la arquitectura y sus traslaciones hacia y desde las prácticas artísticas. Se persigue no tanto hacer una reseña exhaustiva de esta realidad, sino extraer a partir de su constatación una contemporánea lectura crítica de sus potencialidades e interpretaciones
GEOLOGY AND MINERALOGY OF KAOLIN DEPOSITS AT VEREDA BARROBLANCO, OIBA TOWN (SANTANDER): CHARACTERIZATION FOR INDUSTRIAL USES
The Barroblanco (Oiba town, Santander) were characterized by geological and mineralogical studies with the purpose to define a great variety of industrial applications. In this paper also were determined the geological conditions of formation and the reserves were estimated. The kaolin deposit occur as a tabular body emplacement in the medium horizon of the La Cumbre formation and outcrops along the Cerro Negro anticline. The identified minerals by X-ray diffractometry in the seven kaoliniferous levels beside kaolinite are quartz, muscovite/illite, anatase, giibsite and amorphous material. The dertermined mineralogical and chemical properties of kaolin defining its behavior during mineral processing. The kaolin quality after mineral processing was substantially improvement and define the most appropriate use for the production of white cement and high quality ceramics.
Key words: Kaolin, Vereda Barroblanco, kaoliniferous levels, resources.
Los caolines de la Vereda Barroblanco (Municipio de Oiba, Santander) fueron caracterizados desde el punto de vista geológico y mineralógico con el propósito de definir una gama más amplia de usos de esta materia prima mineral en la industria. En este trabajo también se determina el ambiente de depositación y se cuantifican los recursos de caolín. El depósito de caolín es de forma tabular y se localiza en un nivel intermedio de la Formación Cumbre en su Segmento D y aflora a lo largo del Anticlinal de Cerro Negro. Los minerales identificados en los siete niveles caoliniferos aparte de la caolinita son cuarzo, moscovita/illita, anatasa, gibsita y amorfos. Las propiedades mineralógicas y químicas del caolín determinadas sirvieron de base para definir su comportamiento durante el beneficio mineral. La calidad del caolin luego de ser beneficiado aumenta considerablemente y permite su uso en la fabricación de cemento blanco y de cerámica de calidad.
Palabras clave: Caolín, Vereda Barroblanco, niveles caoliniferos, recursos.
 
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