(Table 2) Survivorship of transplanted seedlings of Picea glauca inside and outside three tree islands in 1994, 1995, 2009 and after 15 years

The northern boundary of boreal forest and the ranges of tree species are expected to shift northward in response to climate warming, which will result in a decrease in the albedo of areas currently covered by tundra vegetation, an increase in terrestrial carbon sequestration, and an alteration of biodiversity in the current Low Arctic. Central to the prediction of forest expansion is an increase in the reproductive capacity and establishment of individual trees. We assessed cone production, seed viability, and transplanted seedling success of Picea glauca (Moench.) Voss. (white spruce) in the early 1990s and again in the late 2000s at four forest stand sites and eight tree island sites (clonal populations beyond present treeline) in the Mackenzie Delta region of the Northwest Territories, Canada. Over the past 20 years, average temperatures in this region have increased by 0.9 °C. This area has the northernmost forest-tundra ecotone in North America and is one of the few circumpolar regions where the northern limit of conifer trees reaches the Arctic Ocean. We found that cone production and seed viability did not change between the two periods of examination and that both variables decreased northward across the forest-tundra ecotone. Nevertheless, white spruce individuals at the northern limit of the forest-tundra ecotone produced viable seeds. Furthermore, transplanted seedlings were able to survive in the northernmost sites for 15 years, but there were no signs of natural regeneration. These results indicate that if climatic conditions continue to ameliorate, reproductive output will likely increase, but seedling establishment and forest expansion within the forest-tundra of this region is unlikely to occur without the availability of suitable recruitment sites. Processes that affect the availability of recruitment sites are likely to be important elsewhere in the circumpolar ecotone, and should be incorporated into models and predictions of climate change and its effects on the northern forest-tundra ecotone.

Pedagogía cultural para una educación hacia el encuentro

La categoría de la diferencia ha sido desde siempre puesta en relación dialéctica con la categoría de la igualdad, como objetivo social a conseguir o hacia el cual tender. A pesar de los esfuerzos de los Estados y de las instituciones en esta dirección, se asiste a una continua marginación que golpea a algunos sectores de la población (inmigrantes, discapacitados, ancianos…). Por esto nos preguntamos: ¿es correcto, en el pensamiento que guía las investigaciones, las acciones educativas y sociales, contraponer diferencia e igualdad? ¿Existe alguna otra forma de interrogarnos sobre las diferencias? Escuchamos, en el trabajo cotidiano de los profesionales de la educación y de la salud que hay una urgencia: hace falta encontrar prácticas que conduzcan a vivir mejor, a hacer del Encuentro el centro del propio trabajo. Con esta contribución deseo poner sobre la mesa una de las diferencias que están en la base de nuestro ser en el mundo, la lengua madre, a partir de una experiencia concreta con las familias inmigrantes. El deseo de contribuir a la creación de un pensamiento de la mediación cultural que nos invite al encuentro con las diferencias, propias, y aquellas de los demás, es la piedra angular de este escrito.

Self, writing and feminine transactions in Virginia Woolf's Orlando and Clarice Lispector’s The stream of life

Este artículo realiza un acercamiento a Orlando, de Virginia Woolf, y a Agua viva, de Clarice Lispector, como obras que logran escribir la multiplicidad, la fluidez y la contingencia del ser. Jugando con las convenciones de la biografía y la autobiografía respectivamente, estas obras encuentran los medios para presentar un sujeto multidimensional y para mostrar, en particular, cómo la dimensión relacional, forjada por un orden simbólico patriarcal, ha hecho de la mujer el “otro" del hombre; un “otro" que debe ser dominado. Se exploran en este artículo los conceptos de “economía masculina" y “economía femenina" teorizados por Hélène Cixous y se propone al lenguaje poético como un medio capaz de eludir los dictados del falocentrismo. Lo poético, que no puede ser nunca agotado por uno o varios sistemas de significación, brinda la posibilidad de ir más allá de las categorizaciones y de explorar la multiplicidad. Tanto Orlando como Agua viva muestran las estrategias y las esperanzas de personajes y escritoras que ven en el lenguaje poético, en la “escritura femenina" como la entiende Cixous, el potencial de desarticular la “economía masculina" y abrir un nuevo espacio para sujetos diversos, múltiples y complejos.

Detailed measurements of radium inside a nodule of Albatross 1899-1900 - for Stations 13, 173 and 4658

Thanks to the courtesy of the British Museum of Natural History the author obtained from their Challenger collections two small nodules, and through a similar courtesy of the Mineralogical Department of the Riksmuseum in Stockholm one half of a much larger nodule, also from the Challenger Expedition. Results from his initial measurements of the radium contents of these samples convinced the author that the radium in the nodules is accumulated from the surrounding sediment. In the present paper the author conducted a much more thorough investigation on nodules obtained during the U.S. Albatross cruises of Dr. Agassiz. Detailed measurements of radium were conducted on individual layers and spots inside each nodule.

Performance Comparison Between Serrated Edge and Rolled Edge Reflectors Inside CATR Facilities

CATR facilities are attractive antenna measurement facilities. Main reasons which contribute to this fact lie on its inherent reduced volume, on-the-fly measurements and the extension of both to a wide range of frequencies. However, these features rely on the assumption that the field collimation scheme is able to generate a plane wave distribution (quiet zone) where the AUT is to be placed and operated in RX mode. Unfortunately, electromagnetic theory states that this field distribution is not possible to be generated by a finite size scatterer operated as the collimator of a nonzero wavelength time-harmonic propagating field. This is the background of this paper, where two well-known electromagnetic field collimators will be discussed: the serrated edge reflector and the blended rolled edge reflector. To reach this purpose, electromagnetic hybrid analysis techniques developed at Technical University of Madrid will be applied.

Propagation Mechanism Analysis Before the Break Point Inside Tunnels

There is no unanimous consensus yet on the propagation mechanism before the break point inside tunnels. Some deem that the propagation mechanism follows the free space model, others argue that it should be described by the multimode waveguide model. Firstly, this paper analyzes the propagation loss in two mechanisms. Then, by conjunctively using the propagation theory and the three-dimensional solid geometry, a generic analytical model for the boundary between the free space mechanism and the multi-mode waveguide mechanism inside tunnels has been presented. Three measurement campaigns validate the model in different tunnels at different frequencies. Furthermore, the condition of the validity of the free space model used in tunnel environment has been discussed in some specific situations. Finally, through mathematical derivation, the seemingly conflicting viewpoints on the free space mechanism and the multi-mode waveguide mechanism have been unified in some specific situations by the presented generic model. The results in this paper can be helpful to gain deeper insight and better understanding of the propagation mechanism inside tunnels

Multi-microphone recordings (EigenMike32) inside a WFS system (Iosono) through Ambisonics techniques using Matlab

El audio multicanal ha avanzado a pasos agigantados en los últimos años, y no solo en las técnicas de reproducción, sino que en las de capitación también. Por eso en este proyecto se encuentran ambas cosas: un array microfónico, EigenMike32 de MH Acoustics, y un sistema de reproducción con tecnología Wave Field Synthesis, instalado Iosono en la Jade Höchscule Oldenburg. Para enlazar estos dos puntos de la cadena de audio se proponen dos tipos distintos de codificación: la reproducción de la toma horizontal del EigenMike32; y el 3er orden de Ambisonics (High Order Ambisonics, HOA), una técnica de codificación basada en Armónicos Esféricos mediante la cual se simula el campo acústico en vez de simular las distintas fuentes. Ambas se desarrollaron en el entorno Matlab y apoyadas por la colección de scripts de Isophonics llamada Spatial Audio Matlab Toolbox. Para probar éstas se llevaron a cabo una serie de test en los que se las comparó con las grabaciones realizadas a la vez con un Dummy Head, a la que se supone el método más aproximado a nuestro modo de escucha. Estas pruebas incluían otras grabaciones hechas con un Doble MS de Schoeps que se explican en el proyecto “Sally”. La forma de realizar éstas fue, una batería de 4 audios repetida 4 veces para cada una de las situaciones garbadas (una conversación, una clase, una calle y un comedor universitario). Los resultados fueron inesperados, ya que la codificación del tercer orden de HOA quedo por debajo de la valoración Buena, posiblemente debido a la introducción de material hecho para un array tridimensional dentro de uno de 2 dimensiones. Por el otro lado, la codificación que consistía en extraer los micrófonos del plano horizontal se mantuvo en el nivel de Buena en todas las situaciones. Se concluye que HOA debe seguir siendo probado con mayores conocimientos sobre Armónicos Esféricos; mientras que el otro codificador, mucho más sencillo, puede ser usado para situaciones sin mucha complejidad en cuanto a espacialidad. In the last years the multichannel audio has increased in leaps and bounds and not only in the playback techniques, but also in the recording ones. That is the reason of both things being in this project: a microphone array, EigenMike32 from MH Acoustics; and a playback system with Wave Field Synthesis technology, installed by Iosono in Jade Höchscule Oldenburg. To link these two points of the audio chain, 2 different kinds of codification are proposed: the reproduction of the EigenMike32´s horizontal take, and the Ambisonics´ third order (High Order Ambisonics, HOA), a codification technique based in Spherical Harmonics through which the acoustic field is simulated instead of the different sound sources. Both have been developed inside Matlab´s environment and supported by the Isophonics´ scripts collection called Spatial Audio Matlab Toolbox. To test these, a serial of tests were made in which they were compared with recordings made at the time by a Dummy Head, which is supposed to be the closest method to our hearing way. These tests included other recording and codifications made by a Double MS (DMS) from Schoeps which are explained in the project named “3D audio rendering through Ambisonics techniques: from multi-microphone recordings (DMS Schoeps) to a WFS system, through Matlab”. The way to perform the tests was, a collection made of 4 audios repeated 4 times for each recorded situation (a chat, a class, a street and college canteen or Mensa). The results were unexpected, because the HOA´s third order stood under the Well valuation, possibly caused by introducing material made for a tridimensional array inside one made only by 2 dimensions. On the other hand, the codification that consisted of extracting the horizontal plane microphones kept the Well valuation in all the situations. It is concluded that HOA should keep being tested with larger knowledge about Spherical Harmonics; while the other coder, quite simpler, can be used for situations without a lot of complexity with regards to spatiality.

Fabrication of luminescent nanostructures by electron-beam direct writing of PMMA resist

We report on the conversion of non-luminescent conventional poly(methylmethacrylate) (PMMA)-based electron-beam resists into luminescent materials when used as negative-tone resists, that is, when exposed to high electron irradiation doses. Raman spectroscopy reveals the chemical transformation induced by electron irradiation which is responsible for the observed luminescence in the visible (blue) region. The emission intensity from exposed PMMA-based patterns can be controlled by the electron irradiation dose employed to create them.