911 resultados para top-down approach


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Different socio-economic and environmental drivers lead local communities in mountain regions to adapt land use practices and engage in protection policies. The political system also has to develop new approaches to adapt to those drivers. Local actors are the target group of those policy approaches, and the question arises of if and how much those actors are consulted or even integrated into the design of local land use and protection policies. This article addresses this question by comparing seven different case studies in Swiss mountain regions. Through a formal social network analysis, the inclusion of local actors in collaborative policy networks is investigated and compared to the involvement of other stakeholders representing the next higher sub-national or national decisional levels. Results show that there is a significant difference (1) in how local actors are embedded compared to other stakeholders; and (2) between top-down versus bottom-up designed policy processes.

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One of the current challenges in evolutionary ecology is understanding the long-term persistence of contemporary-evolving predator–prey interactions across space and time. To address this, we developed an extension of a multi-locus, multi-trait eco-evolutionary individual-based model that incorporates several interacting species in explicit landscapes. We simulated eco-evolutionary dynamics of multiple species food webs with different degrees of connectance across soil-moisture islands. A broad set of parameter combinations led to the local extinction of species, but some species persisted, and this was associated with (1) high connectance and omnivory and (2) ongoing evolution, due to multi-trait genetic variability of the embedded species. Furthermore, persistence was highest at intermediate island distances, likely because of a balance between predation-induced extinction (strongest at short island distances) and the coupling of island diversity by top predators, which by travelling among islands exert global top-down control of biodiversity. In the simulations with high genetic variation, we also found widespread trait evolutionary changes indicative of eco-evolutionary dynamics. We discuss how the ever-increasing computing power and high-resolution data availability will soon allow researchers to start bridging the in vivo–in silico gap.

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Many people routinely criticise themselves. While self-criticism is largely unproblematic for most individuals, depressed patients exhibit excessive self-critical thinking, which leads to strong negative affects. We used functional magnetic resonance imaging in healthy subjects (N = 20) to investigate neural correlates and possible psychological moderators of self-critical processing. Stimuli consisted of individually selected adjectives of personally negative content and were contrasted with neutral and negative non-self-referential adjectives. We found that confrontation with self-critical material yielded neural activity in regions involved in emotions (anterior insula/hippocampus-amygdala formation) and in anterior and posterior cortical midline structures, which are associated with self-referential and autobiographical memory processing. Furthermore, contrasts revealed an extended network of bilateral frontal brain areas. We suggest that the co-activation of superior and inferior lateral frontal brain regions reflects the recruitment of a frontal top-down pathway, representing cognitive reappraisal strategies for dealing with evoked negative affects. In addition, activation of right superior frontal areas was positively associated with neuroticism and negatively associated with cognitive reappraisal. Although these findings may not be specific to negative stimuli, they support a role for clinically relevant personality traits in successful regulation of emotion during confrontation with self-critical material.

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This study describes and discusses initiatives taken by public (water) agencies in the state of Brandenburg in Germany, the state of California in the USA and the Ebro River Basin in Spain in response to the challenges which climate change poses for the agricultural water sector. The drivers and actors and the process of changing agricultural water governance are its particular focus. The assumptions discussed are: (i) the degree of planned and anticipatory top-down implementation processes decreases if actions are more decentralized and are introduced at the regional and local level; (ii) the degree of autonomous and responsive adaptation approaches seems to grow with actions at a lower administrative level. Looking at processes of institutional change, a variety of drivers and actors are at work such as changing perceptions of predicted climate impacts; international obligations which force politicians to take action; socio-economic concerns such as the cost of not taking action; the economic interests of the private sector. Drivers are manifold and often interact and, in many cases, reforms in the sector are driven by and associated with larger reform agendas. The results of the study may serve as a starting point in assisting water agencies in developing countries with the elaboration of coping strategies for tackling climate change-induced risks related to agricultural water management.

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This chapter aims to overcome the gap existing between case study research, which typically provides qualitative and process-based insights, and national or global inventories that typically offer spatially explicit and quantitative analysis of broader patterns, and thus to present adequate evidence for policymaking regarding large-scale land acquisitions. Therefore, the chapter links spatial patterns of land acquisitions to underlying implementation processes of land allocation. Methodologically linking the described patterns and processes proved difficult, but we have identified indicators that could be added to inventories and monitoring systems to make linkage possible. Combining complementary approaches in this way may help to determine where policy space exists for more sustainable governance of land acquisitions, both geographically and with regard to processes of agrarian transitions. Our spatial analysis revealed two general patterns: (i) relatively large forestry-related acquisitions that target forested landscapes and often interfere with semi-subsistence farming systems; and (ii) smaller agriculture-related acquisitions that often target existing cropland and also interfere with semi-subsistence systems. Furthermore, our meta-analysis of land acquisition implementation processes shows that authoritarian, top-down processes dominate. Initially, the demands of powerful regional and domestic investors tend to override socio-ecological variables, local actors’ interests, and land governance mechanisms. As available land grows scarce, however, and local actors gain experience dealing with land acquisitions, it appears that land investments begin to fail or give way to more inclusive, bottom-up investment models.

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We tested the predictions of Attentional Control Theory (ACT) by examining how anxiety affects visual search strategies, performance efficiency, and performance effectiveness using a dynamic, temporal-constrained anticipation task. Higher and lower skilled players viewed soccer situations under 2 task constraints (near vs. far situation) and were tested under high (HA) and low (LA) anxiety conditions. Response accuracy (effectiveness) and response time, perceived mental effort, and eye-movements (all efficiency) were recorded. A significant increase in anxiety was evidenced by higher state anxiety ratings on the MRF-L scale. Increased anxiety led to decreased performance efficiency because response times and mental effort increased for both skill groups whereas response accuracy did not differ. Anxiety influenced search strategies, with higher skilled players showing a decrease in number of fixation locations for far situations under HA compared with LA condition when compared with lower skilled players. Findings provide support for ACT with anxiety impairing processing efficiency and, potentially, top-down attentional control across different task constraints.

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Schizophrenia patients show abnormalities in a broad range of task demands. Therefore, an explanation common to all these abnormalities has to be sought independently of any particular task, ideally in the brain dynamics before a task takes place or during resting state. For the neurobiological investigation of such baseline states, EEG microstate analysis is particularly well suited, because it identifies subsecond global states of stable connectivity patterns directly related to the recruitment of different types of information processing modes (e.g., integration of top-down and bottom-up information). Meanwhile, there is an accumulation of evidence that particular microstate networks are selectively affected in schizophrenia. To obtain an overall estimate of the effect size of these microstate abnormalities, we present a systematic meta-analysis over all studies available to date relating EEG microstates to schizophrenia. Results showed medium size effects for two classes of microstates, namely, a class labeled C that was found to be more frequent in schizophrenia and a class labeled D that was found to be shortened. These abnormalities may correspond to core symptoms of schizophrenia, e.g., insufficient reality testing and self-monitoring as during auditory verbal hallucinations. As interventional studies have shown that these microstate features may be systematically affected using antipsychotic drugs or neurofeedback interventions, these findings may help introducing novel diagnostic and treatment options.

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Mental imagery and perception are thought to rely on similar neural circuits, and many recent behavioral studies have attempted to demonstrate interactions between actual physical stimulation and sensory imagery in the corresponding sensory modality. However, there has been a lack of theoretical understanding of the nature of these interactions, and both interferential and facilitatory effects have been found. Facilitatory effects appear strikingly similar to those that arise due to experimental manipulations of expectation. Using a self-motion discrimination task, we try to disentangle the effects of mental imagery from those of expectation by using a hierarchical drift diffusion model to investigate both choice data and response times. Manipulations of expectation are reasonably well understood in terms of their selective influence on parameters of the drift diffusion model, and in this study, we make the first attempt to similarly characterize the effects of mental imagery. We investigate mental imagery within the computational framework of control theory and state estimation. • Mental imagery and perception are thought to rely on similar neural circuits; however, on more theoretical grounds, imagery seems to be closely related to the output of forward models (sensory predictions). • We reanalyzed data from a study of imagined self-motion. • Bayesian modeling of response times may allow us to disentangle the effects of mental imagery on behavior from other cognitive (top-down) effects, such as expectation.

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Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh nets or a WP-2 net 50 µm mesh size equipped with a non-filtering cod-end. Sampling was conducted at various times of day at the different stations. The nets were hauled with a speed of 0.2-0.3 m s**-1 from 100, 75 and 50 m depth to the surface at St. 2 + 4, 5 and 6, respectively. The content was immediately preserved in buffered formalin (4% final concentration). All samples were analyzed in the Plankton sorting and identification center in Szczecin (www.nmfri.gdynia.pl). Samples containing high numbers of zooplankton were split into subsamples. All copepods and other zooplankton were identified down to lowest possible taxonomic level (approx. 400 per sample), length measured and counted. Copepods were sorted into development stages (nauplii stage 1 - copepodite stage 6) using morphological features and sizes, and up to 10 individuals of each stage was length measured.

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Increasing seawater temperature and CO2 concentrations both are expected to increase coastal phytoplankton biomass and carbon to nutrient ratios in nutrient limited seasonally stratified summer conditions. This is because temperature enhances phytoplankton growth while grazing is suggested to be reduced during such bottom-up controlled situations. In addition, enhanced CO2 concentrations potentially favor phytoplankton species, that otherwise depend on costly carbon concentrating mechanisms (CCM). The trophic consequences for consumers under such conditions, however, remain little understood. We set out to experimentally explore the combined effects of increasing temperature and CO2 concentration for phytoplankton biomass and stoichiometry and the consequences for trophic transfer (here for copepods) on a natural nutrient limited Baltic Sea summer plankton community. The results show, that warming effects were translated to the next trophic level by switching the system from a bottom-up controlled to a mainly top-down controlled one. This was reflected in significantly down-grazed phytoplankton and increased zooplankton abundance in the warm temperature treatment (22.5°C). Additionally, at low temperature (16.5°C) rising CO2 concentrations significantly increased phytoplankton biomass. The latter effect however, was due to direct negative impact of CO2 on copepod nauplii which released phytoplankton from grazing in the cold but not in the warm treatments. Our results suggest that future seawater warming has the potential to switch trophic relations between phytoplankton and their grazers under nutrient limited conditions with the consequence of potentially disguising CO2 effects on coastal phytoplankton biomass.

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El proyecto PODECI se planteó como una propuesta de investigación básica y aplicada encaminada a describir, analizar, acompañar y comparar críticamente experiencias concretas de desarrollo local en distintos municipios de la Provincia de Misiones. Desde un comienzo se optó por la participación directa del equipo técnico profesional en los espacios multiactorales constituidos en cada ámbito local a fin de promover la participación de las autoridades, la población y las organizaciones locales en el cambio y la transformación económica, política, social y cultural. El Proyecto se ha sustentado en una perspectiva teórico-metodológica que asume que el desarrollo local participativo posibilitará la configuración de estrategias ciudadanas fundadas en el compromiso social. Ello supone una vía pertinente para generar en las poblaciones locales prácticas democráticas innovadoras, empoderar la sociedad civil y proponer proyectos, social y políticamente sustentados. Desde esta perspectiva se cuestiona la validez y la viabilidad de proyectos dirigidos de desarrollo (top-down), que no promueven la participación efectiva y eficaz de la mayoría de los sectores que componen una comunidad; ni alientan la producción, consolidación e institucionalización de prácticas organizativas democráticas y consensuadas. En suma: difícilmente podrá avanzarse en el camino del desarrollo, sin fortalecer significativamente los “dispositivos de ciudadanización”. En tanto investigación aplicada, el Proyecto PODECI se encaminó a describir, analizar y comparar experiencias concretas de desarrollo, mediante la participación directa del equipo técnico en los espacios multiactorales constituidos a nivel local para promover el cambio y la transformación económica, política, social y cultural. La esencia del planteamiento asumido desde el Proyecto PODECI ha sido que toda estrategia de desarrollo basada en la participación requiere el compromiso pleno con la población, en la medida en que: 1. las relaciones deben ser directas y estar orientadas a la demanda, 2. las decisiones en materia de políticas públicas deben adoptarse en un contexto participativo y no depender de la simple voluntad o interés de los funcionarios de turno y 3. la propia acción gubernamental deberá activar espacios públicos multiactorales de concertación, negociación y gestión asociada. Se entiende de este modo, que la participación de los grupos y actores de los sectores más vulnerables de la sociedad en estos espacios implica en si mismo un avance en los procesos de empoderamiento y democratización.

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Rising seawater temperature and CO2 concentrations (ocean acidification) represent two of the most influential factors impacting marine ecosystems in the face of global climate change. In ecological climate change research full-factorial experiments across seasons in multi-species, cross-trophic level set-ups are essential as they allow making realistic estimations about direct and indirect effects and the relative importance of both major environmental stressors on ecosystems. In benthic mesocosm experiments we tested the responses of coastal Baltic Sea Fucus vesiculosus communities to elevated seawater temperature and CO2 concentrations across four seasons of one year. While increasing [CO2] levels only had minor effects, warming had strong and persistent effects on grazers which affected the Fucus community differently depending on season. In late summer a temperature-driven collapse of grazers caused a cascading effect from the consumers to the foundation species resulting in overgrowth of Fucus thalli by epiphytes. In fall/ winter, outside the growing season of epiphytes, intensified grazing under warming resulted in a significant reduction of Fucus biomass. Thus, we confirm the prediction that future increasing water temperatures influence marine food-web processes by altering top-down control, but we also show that specific consequences for food-web structure depend on season. Since Fucus vesiculosus is the dominant habitat-forming brown algal system in the Baltic Sea, its potential decline under global warming implicates the loss of key functions and services such as provision of nutrient storage, substrate, food, shelter and nursery grounds for a diverse community of marine invertebrates and fish in Baltic Sea coastal waters.

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Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh nets or a WP-2 net 50 µm mesh size equipped with a non-filtering cod-end. Sampling was conducted at various times of day at the different stations. The nets were hauled with a speed of 0.2-0.3 m s**-1 from 100, 75 and 50 m depth to the surface at St. 2 + 4, 5 and 6, respectively. The content was immediately preserved in buffered formalin (4% final concentration). All samples were analyzed in the Plankton sorting and identification center in Szczecin (www.nmfri.gdynia.pl). Samples containing high numbers of zooplankton were split into subsamples. All copepods and other zooplankton were identified down to lowest possible taxonomic level (approx. 400 per sample), length measured and counted. Copepods were sorted into development stages (nauplii stage 1 - copepodite stage 6) using morphological features and sizes, and up to 10 individuals of each stage was length measured.

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El trabajo que se presenta se referencia en una serie de propuestas de ordenamiento territorial desarrolladas de manera conjunta entre municipios de la provincia de San Juan, Argentina y la Universidad Nacional de San Juan. Se trata de propuestas que abordan múltiples desafíos, los que no por recurrentes minimizan su complejidad. Por el contrario señalan la transición hacia la construcción de territorios más sostenibles en este contexto particular, enfrentan el desafío que supone la disputa por el suelo urbano, las tensiones derivadas del avance de la urbanización y la expectativa de valorización inmobiliaria por parte de sectores del periurbano. Se propone una transformación del propio territorio, sostenida en la construcción de capacidades locales, en el afianzamiento de redes, y en la concienciación sobre las propias capacidades. Los resultados alcanzados desde lo 'tangible' refieren a propuestas orientadas en tres direcciones principales: reestructuración espacial y funcional, reestructuración socio-productiva y gestión integrada de recursos patrimoniales. Más allá de estos resultados, vinculados al diseño de estrategias de ocupación y manejo sustentable del territorio se destacan diversas construcciones, como el reconocimiento e incorporación de nuevos actores, el fortalecimiento de lazos entre actores locales y externos a la comunidad: Universidad, Gobierno provincial, Municipios; la continuidad de proyectos, la socialización de resultados con otros municipios, los proyectos en marcha. En este sentido, actualmente se trabaja en la construcción del Plan para el Area Metropolitana de San Juan, en una conjunción de voluntades políticas, sociales y técnicas, involucrando a seis municipios de la provincia. Indudablemente, se trata de procesos que requieren complementariamente o simultáneamente de aquellos 'microprocesos' a escala de las comunidades, que se transformen en 'micrologros', en una estrategia que integre procesos 'top down' y 'bottom up'. Éste es un camino que se comienza a recorrer. Concluyendo, se valora especialmente, el rol dinamizador que los procesos desarrollados han provocado en el entorno local, generando nuevas propuestas, atrayendo programas y acciones concretas hacia el territorio. Se comienza a transitar de una manera sostenida, la incorporación del tema planificación en la agenda de gobierno, la construcción de microprocesos en distintas comunidades, y la Universidad recuperando su rol, no sólo como consultor de referencia en estas temáticas, sino esencialmente como 'caja de resonancia' de las necesidades y deseabilidades de esta comunidad. En síntesis, se espera que estos procesos de transición alcancen la necesaria escala de transformación

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El presente artículo tiene como objetivo analizar la dinámica que adquieren las relaciones de dominio señorial al interior del señorío de la Casa de los Velasco, Condestables hereditarios del reino de Castilla, partiendo de la forma que adopta la intrincada red de agentes y administradores señoriales a su servicio ubicados en el nivel de las aldeas y villas que forman parte de la zona oriental de Cantabria entre los siglos XIV al XVI. Para ello, estableceremos los diversos mecanismos de solidaridad, dependencia y sujeción de los cuales se vale el señor para ejercer su jurisdicción y poder de mando sobre este conjunto plural de comunidades y hombres. Es decir, nuestra intención es estudiar el proceso de construcción del poder señorial a partir de una imagen dinámica que le brinde dimensión y profundidad y que, al mismo tiempo, permita entender la constitución del dominio político señorial no sólo como una imposición de arriba hacia abajo, sino también como un espacio de negociación en permanente rearticulación que involucra tanto al señor, su parentela y clientela, como a las comunidades jerarquizadas, tanto rurales como urbanas, que se encuentran sometidas a su poder