Space Competition and Time Delays in Human Range Expansions. Application to the Neolithic Transition

Space competition effects are well-known in many microbiological and ecological systems. Here we analyze such an effectin human populations. The Neolithic transition (change from foraging to farming) was mainly the outcome of a demographic process that spread gradually throughout Europe from the Near East. In Northern Europe, archaeological data show a slowdown on the Neolithic rate of spread that can be related to a high indigenous (Mesolithic) population density hindering the advance as a result of the space competition between the two populations. We measure this slowdown from a database of 902 Early Neolithic sites and develop a time-delayed reaction-diffusion model with space competition between Neolithic and Mesolithic populations, to predict the observed speeds. The comparison of the predicted speed with the observations and with a previous non-delayed model show that both effects, the time delay effect due to the generation lag and the space competition between populations, are crucial in order to understand the observations

Impairment of the Bacterial Biofilm Stability by Triclosan

The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS) in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition – isolated from sediments of the Eden Estuary (Scotland, UK) – on non-cohesive glass beads (,63 mm) and exposed to a range of triclosan concentrations (control, 2 – 100 mg L21) was monitored over time by Magnetic Particle Induction (MagPI). In parallel, bacterial cell numbers, division rate, community composition (DGGE) and EPS (extracellular polymeric substances: carbohydrates and proteins) secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI) of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality) were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of ecosystem effects

Climate Change or Land Use Dynamics: Do We Know What Climate Change Indicators Indicate?

Different components of global change can have interacting effects on biodiversity and this may influence our ability to detect the specific consequences of climate change through biodiversity indicators. Here, we analyze whether climate change indicators can be affected by land use dynamics that are not directly determined by climate change. To this aim, we analyzed three community-level indicators of climate change impacts that are based on the optimal thermal environment and averagelatitude of the distribution of bird species present at local communities. We used multiple regression models to relate the variation in climate change indicators to: i) environmental temperature; and ii) three landscape gradients reflecting important current land use change processes (land abandonment, fire impacts and urbanization), all of them having forest areas at their positive extremes. We found that, with few exceptions, landscape gradients determined the figures of climate change indicators as strongly as temperature. Bird communities in forest habitats had colder-dwelling bird species with more northerndistributions than farmland, burnt or urban areas. Our results show that land use changes can reverse, hide or exacerbate our perception of climate change impacts when measured through community-level climate change indicators. We stress the need of an explicit incorporation of the interactions between climate change and land use dynamics to understand what are current climate change indicators indicating and be able to isolate real climate change impacts

Rapid Biodiversity Assessment and Monitoring Method for Highly Diverse Benthic Communities: A Case Study of Mediterranean Coralligenous Outcrops

Increasing anthropogenic pressures urge enhanced knowledge and understanding of the current state of marine biodiversity. This baseline information is pivotal to explore present trends, detect future modifications and propose adequate management actions for marine ecosystems. Coralligenous outcrops are a highly diverse and structurally complex deep-water habitat faced with major threats in the Mediterranean Sea. Despite its ecological, aesthetic and economic value, coralligenous biodiversity patterns are still poorly understood. There is currently no single sampling method that has been demonstrated to be sufficiently representative to ensure adequate community assessment and monitoring in this habitat. Therefore, we propose a rapid non-destructive protocol for biodiversity assessment and monitoring of coralligenous outcrops providing good estimates of its structure and species composition, based on photographic sampling and the determination of presence/absence of macrobenthic species. We used an extensive photographic survey, covering several spatial scales (100s of m to 100s of km) within the NW Mediterranean and including 2 different coralligenous assemblages: Paramuricea clavata (PCA) and Corallium rubrum assemblage (CRA). This approach allowed us to determine the minimal sampling area for each assemblage (5000 cm² for PCA and 2500 cm²for CRA). In addition, we conclude that 3 replicates provide an optimal sampling effort in order to maximize the species number and to assess the main biodiversity patterns of studied assemblages in variability studies requiring replicates. We contend that the proposed sampling approach provides a valuable tool for management and conservation planning, monitoring and research programs focused on coralligenous outcrops, potentially also applicable in other benthic ecosystems

Bioelectrochemical Treatment of Contaminated Groundwater

To remove these pollutants from groundwater, different technologies can be used. Currently, the Environmental Protection Agency (EPA) considers ion exchange, reverse osmosis and reverse electrodialysis to be effective methods for the decrease of their concentrations, below their limit in drinking water. These technologies have some drawbacks, such as low selectivity towards the target pollutant, high energy or chemicals requirements, and the generation of waste brine (pollutants are separated from water, not treated), which require an additional treatment. Bio Electro Chemical Systems (BES) could fill this niche

Estilos comunicativos, vinculación universitaria y adaptación psicosocial

El presente estudio aborda la relación entre los estilos comunicativos de los estudiantes universitarios, su vinculación en la universidad y el nivel de adaptación psicosocial. Se analizan distintos estilos comunicativos en relación con el grado de vinculación universitaria y su influencia sobre el nivel de ansiedad, distimia, consumo de alcohol y dependencia de sustancias. Los datos han sido obtenidos mediante cuestionario administrado a una muestra representativa de 529 estudiantes universitarios. Los resultados indican la existencia de diferencias de género con respecto a algunos patrones comunicativos pero no en relación con la vinculación universitaria. Se constata también una relación estadísticamente significativa, aunque no muy elevada, entre los estilos comunicativos y la capacidad de los estudiantes para vincularse en el contexto universitario. Tanto los estilos comunicativos como la vinculación universitaria contribuyen a la explicación de la sintomatología afectiva, pero sólo los estilos comunicativos polémico y amigable contribuyen a la explicación del consumo de sustancias

Dimensiones psicopatológicas asociadas al consumo de tabaco en población universitaria

El presente estudio pretende examinar la relación entre malestar psicológico y consumo de tabaco en una muestra de 1.242 estudiantes universitarios seleccionados aleatoriamente. Los resultados muestran una asociación significativa positiva entre el estatus psicopatológico de los participantes y el consumo de cigarrillos. Además, los resultados demuestran que el consumo de tabaco también está significativamente relacionado con la percepción subjetiva de acontecimientos vitales estresantes, la automedicación y la realización de comportamientos alimentarios irregulares. De acuerdo con la hipótesis de automedicación, los datos sugieren que fumar ayuda a los fumadores a afrontar los estados afectivos negativos, lo cual debería tenerse en cuenta en los programas de prevención y de deshabituación del tabaco, con el fin de aumentar el control emocional y las estrategias de afrontamiento

Determinantes del progreso en los estudios de doctorado. Diferencias entre disciplinas científico-tecnológicas versus ciencias sociales y humanidades

En numerosos países, incluido España, existen problemas en relación con las tasas de éxito en los estudios de doctorado. El trabajo que aquí se presenta fue diseñado con el fin de identificar los factores asociados con el progreso durante el tercer ciclo y la elaboración de las tesis doctorales en dos grupos disciplinares: científico-tecnológico versus humanidades y ciencias sociales. El artículo presenta la información obtenida a partir de un cuestionario aplicado a 81 estudiantes de doctorado de la Universidad de Girona, en relación con tres áreas de interés: variables económicas, personales y académicas que condicionan el éxito en el tercer ciclo. Los resultados muestran diferencias substanciales entre disciplinas. Los factores responsables de estas diferencias son, principalmente: la vinculación profesional a la universidad, la planificación del proyecto de investigación y los objetivos personales.

Low environmental impact bleaching sequences for attaining high brightness level with eucalyptus SPP pulp

The alternatives used for minimizing the usage of chlorine dioxide in bleaching sequences included a hot acid hydrolysis (Ahot) stage, the use of hot chlorine dioxide (Dhot) and ozone stages at medium consistency and high consistency (Zmc and Zhc), in addition to stages with atmospheric hydrogen peroxide (P) and pressurized hydrogen peroxide (PO). The results were interpreted based on the cost of the chemical products, bleaching process yields and on minimizing the environmental impact of the bleaching process. In spite of some process restrictions, high ISO brightness levels were kept around 90 % brightness. Additionally, the inclusion of stages like acid hydrolysis, pressurized peroxide and ozone in the bleaching sequences provided an increase in operating flexibility, aimed at reducing environmental impact (ECF Light). The Dhot(EOP)D(PO) sequence presented lower operating cost for ISO brightness above 92 %. However, this kind of sequence was not allowed for closing the wastewater circuit, even partially. For ISO brightness level around 91%, the AhotZhcDP sequence presented a lower operating cost than the others

The ViRVIG Institute

In this paper we present the ViRVIG Institute, a recently created institution that joins two well-known research groups: MOVING in Barcelona, and GGG in Girona. Our main research topics are Virtual Reality devices and interaction techniques, complex data models, realistic materials and lighting, geometry processing, and medical image visualization. We briefly introduce the history of both research groups and present some representative projects. Finally, we sketch our lines for future research

Empatía y tolerancia a la diversidad en un contexto educativo intercultural = Empathy and tolerance of diversity in an intercultural educative setting

Las relaciones entre empatía y conducta prosocial han estado ampliamente estudiadas desde hace años. Sin embargo, no existen estudios que utilicen estudiantes indígenas y mestizos de una universidad intercultural. El objetivo principal de la investigación fue analizar la tolerancia a la diversidad en relación a la empatía. La muestra estaba formada por 534 indígenas y mestizos, de edades comprendidas entre los 17 y los 22 años. Los resultados mostraron que los estudiantes con una alta capacidad empática eran también más tolerantes. Las chicas puntuaron significativamente superior en tolerancia y empatía que los chicos. Se encuentran diferencias entre indígenas y mestizos y entre universidad intercultural y universidad pública en relación a áreas específicas de la tolerancia a la diversidad

El Sinuoso fluir de la psicología crítica: una conversación con Teresa Cabruja Ubach

En esta entrevista Teresa Cabruja considera los orígenes y el desarrollo de la Psicología crítica en España, así como el lugar de su trabajo en relación con la constitución de este campo. A lo largo de la entrevista emergen momentos claves en los cuales se va configurando un conocimiento psicológico, que se aparta de las visiones convencionales de la disciplina. Se resalta la importancia que tienen los nodos locales para la producción de las perspectivas críticas, así como los encuentros internacionales para la expansión y cimentación de estas visiones alternativas al conocimiento psicológico convencional

¿Quién teme a la psicología feminista? Reflexiones sobre las construcciones discursivas de profesores, estudiantes y profesionales de psicología para que cuando el género entre en el aula, el feminismo no salga por la ventana

En el texto se problematizará la inclusión del género en psicología a partir de las construcciones discursivas obtenidas en una investigación cualitativa sobre las opiniones de estudiantes, profesores y profesionales. Dado que la mayor aceptación asimila “género” a “diferencia sexual” desde la tradición positivista y dualista, se neutraliza su capacidad transformadora. Esta versión “descomprometida” del género, se disocia discursivamente del feminismo social y las epistemologías feministas que generan mayores resistencias y temores. Tal y como argumentaré, una psicología positivista con su supuesta neutralidad y objetividad así como la permanencia de un imaginario androcéntrico y etnocéntrico dificultan la capacidad de cuestionar una psicología poco sensible a las relaciones de poder. Finamente, propongo la necesidad de combinar un análisis del currículo oculto con una comprensión de las argumentaciones y creencias que forman parte de la vida cotidiana del ejercicio y docencia de la psicología. Así se pueden retomar de forma conjunta los mecanismos de (re)producción y difusión de la ciencia con las relaciones e interacciones académicas y profesionales marcadas por el sistema sexo-género, que operan de forma compleja en las combinaciones de ciencia e ideología o discurso y acción

Aportacions des de la perspectiva de l'estructura social a la realitat lingüística

Des la perspectiva sociològica, dos són els punts clau a destacar: la importància d'entendre la realitat lingüística separadament pels catalanoparlants i els castellanoparlants; i la importància, malgrat la dificultat, d'actuar sobre l'ús de la llengua en el marc social, cultural, polític i legal que tenim

Poverty and living arrangements among youth in Spain, 1980-2005

One of the most relevant demographic events in Spain from a recent historical perspective was the baby boom of the 1960s and 1970s. The “adapting to circumstances” of these generations of youth and their families through delayed emancipation and childbearing has been key in preventing a decline in their economic status. The results show that the reduction of the poverty risk among non-emancipated youth for the period 1980-2005 is explained by the fact that an increasing number of young Spaniards live with two employed parents. Thus, emancipation delay is found most in those families that can best afford it. Furthermore, the salaries of young workers remaining in the parental home have become an important factor in reducing their family poverty risk. On the other hand, fertility decline is readily explained by the economic difficulties young couples encounter in sustaining their offspring