Gliotransmitters travel in time and space.

The identification of the presence of active signaling between astrocytes and neurons in a process termed gliotransmission has caused a paradigm shift in our thinking about brain function. However, we are still in the early days of the conceptualization of how astrocytes influence synapses, neurons, networks, and ultimately behavior. In this Perspective, our goal is to identify emerging principles governing gliotransmission and consider the specific properties of this process that endow the astrocyte with unique functions in brain signal integration. We develop and present hypotheses aimed at reconciling confounding reports and define open questions to provide a conceptual framework for future studies. We propose that astrocytes mainly signal through high-affinity slowly desensitizing receptors to modulate neurons and perform integration in spatiotemporal domains complementary to those of neurons

Coconut coir as a sustainable nursery growing media for seedling production of the ecologically diverse quercus species

Peat, a non-sustainable resource, is still predominately used in forest nurseries. Coconut coir might provide an alternative, renewable, and reliable growing media but few studies have evaluated this media type in forest nurseries. We assessed the influence of pure coir, in combination with various fertilization regimes, on the growth and physiology of three ecologically diverse Quercus species seedlings (Q. robur, Q. pubescens, and Q. ilex) during nursery cultivation. Seedlings were grown using peat and pure coir in combination with three fertilization treatments (standard, K-enriched, and P-enriched). Data were collected for: (1) growth and physiological traits; (2) detailed above- and below-ground morphological traits by destructive analysis; and (3) NPK content in leaves, shoot and roots, and in the growing media, following cultivation. Peat and coir in combination with the various fertilization treatments affected above- and below-ground morphology and, to a lesser extent, the physiological traits of Quercus seedlings. Large effects of the substrate occurred for most morphological variables, with peat being more effective than coir in all studied species. Fertilization also produced significant differences. The effect of K-enriched fertilization on plant growth was clear across the three species and the two growing media. P-enriched fertilization in peat was the only combination that promoted a higher amount of this element in the tissues at the end of cultivation. Despite their smaller size, seedlings produced in coir were compatible with standard Quercus forest stocktype size, and showed a proportionally higher root system development and fibrosity. Our results suggest that coir can be used as an alternative substrate to grow Quercus species seedlings, and that fertilization can offset coir deficiencies in chemical properties. As several functional traits drive planting performance under varying environmental conditions. according to the Target Plant Concept, coir might thus serve as an acceptable material for seedling cultivation in some cases

Proyecto SYMBCITY del Solar Decathlon Europe 2014: redensificación sostenible como forma de intervención urbana en tiempos de crisis

Based on the concept of «sustainable redensification» we propose the colonization or refurbishment of available spaces on the roof, lower floors or between walls of existing buildings, for demanded uses in each city district, and the retrofit of its facades, generating a new urban unit that gives birth to a symbiotic organism benefitting all parties involved. This increase of density and its exploitation will allow financing the energy and accessibility improvement of the occupied building that shares its land. This project is part of the development of the prototype by the Plateau Team, formed by Alcala University and Castilla-La Mancha University, selected team for the «Solar Decathlon 2014» competition. This innovative urban re-generation proposal includes urban, social, technical and economic analysis, searches for new places of business opportuni-ties, and creates a symbiosis between the new and the old to improve the energy efficiency of existing buildings.Partiendo del concepto de «redensificación sostenible» se propone la colonización o reordenación de espacios disponibles sobre la cubierta, bajos o entre medianeras de edificaciones existentes, para usos demandados en cada barrio, y el desarro-llo de sus fachadas, generando un nuevo conjunto urbano que en su asociación origina un organismo simbiótico benefician-do a todas las partes implicadas. Este aumento de edificabilidad y su explotación permitirá la financiación de las mejoras energéticas y de accesibilidad de la edificación ocupada que cede su terreno. Este proyecto forma parte del desarrollo del prototipo del equipo Plateau Team, formado por las Universidades de Alcalá y Castilla-La Mancha, seleccionado para la competición «Solar Decathlon 2014». Esta apuesta innovadora de regeneración urbana incluye el análisis urbano, social, técnico y económico, busca nuevos lugares de oportunidad y crea una simbiosis entre lo nuevo y lo antiguo mejorando la eficiencia energética del parque de viviendas existente

Proyecto SYMBCITY del Solar Decathlon Europe 2014: redensificación sostenible como forma de intervención urbana en tiempos de crisis

Based on the concept of «sustainable redensification» we propose the colonization or refurbishment of available spaces on the roof, lower floors or between walls of existing buildings, for demanded uses in each city district, and the retrofit of its facades, generating a new urban unit that gives birth to a symbiotic organism benefitting all parties involved. This increase of density and its exploitation will allow financing the energy and accessibility improvement of the occupied building that shares its land. This project is part of the development of the prototype by the Plateau Team, formed by Alcala University and Castilla-La Mancha University, selected team for the «Solar Decathlon 2014» competition. This innovative urban re-generation proposal includes urban, social, technical and economic analysis, searches for new places of business opportuni-ties, and creates a symbiosis between the new and the old to improve the energy efficiency of existing buildings.<br><br>Partiendo del concepto de «redensificación sostenible» se propone la colonización o reordenación de espacios disponibles sobre la cubierta, bajos o entre medianeras de edificaciones existentes, para usos demandados en cada barrio, y el desarro-llo de sus fachadas, generando un nuevo conjunto urbano que en su asociación origina un organismo simbiótico benefician-do a todas las partes implicadas. Este aumento de edificabilidad y su explotación permitirá la financiación de las mejoras energéticas y de accesibilidad de la edificación ocupada que cede su terreno. Este proyecto forma parte del desarrollo del prototipo del equipo Plateau Team, formado por las Universidades de Alcalá y Castilla-La Mancha, seleccionado para la competición «Solar Decathlon 2014». Esta apuesta innovadora de regeneración urbana incluye el análisis urbano, social, técnico y económico, busca nuevos lugares de oportunidad y crea una simbiosis entre lo nuevo y lo antiguo mejorando la eficiencia energética del parque de viviendas existente

Should we use meshes or solid tube shelters when planting in Mediterranean semiarid environments?

Tree shelters in Mediterranean environments have a two-sided effect. They not only protect seedlings from browsing but also ameliorate microclimatic conditions, improving post-planting survival and growth. However, the ecophysiological basis of these effects are poorly understood. A factorial experiment combining light transmissivity and shelter type (solid tube vs. mesh wall) was carried out to assess the impact of contrasting microclimatic characteristics on seedling performance and physiological stress levels of shelters in two Mediterranean shrubland species (Quercus coccifera and Rhamnus lycioides) planted in a semiarid site. Even though seedlings in solid tube shelters experienced higher temperature and were slightly more photoinhibited, they had higher predawn water potential and, in general, better survival and growth than in mesh wall shelters. However, these effects were species-specific, with Rh. lycioides more favoured by solid wall shelters than Q. coccifera. However, root growth cannot explain these interactions between species and shelter type on seedling survival. Since light transmission had a marginal effect compared with wall type, we proposed that the observed effects and interaction with species are not dependent on light intensity or temperature but on other microclimatic differences like air velocity or light quality and distribution. Further studies should assess the importance of these factors on post-planting growth and physiological stress levels, which can be critical for matching the correct tree shelters type for each species in plantations in semiarid environments

Strategies in PRholog

PRholog is an experimental extension of logic programming with strategic conditional transformation rules, combining Prolog with Rholog calculus. The rules perform nondeterministic transformations on hedges. Queries may have several results that can be explored on backtracking. Strategies provide a control on rule applications in a declarative way. With strategy combinators, the user can construct more complex strategies from simpler ones. Matching with four different kinds of variables provides a flexible mechanism of selecting (sub)terms during execution. We give an overview on programming with strategies in PRholog and demonstrate how rewriting strategies can be expressed

Astrocytes Optimize the Synaptic Transmission of Information

Chemical synapses transmit information via the release of neurotransmitter-filled vesicles from the presynaptic terminal. Using computational modeling, we predict that the limited availability of neurotransmitter resources in combination with the spontaneous release of vesicles limits the maximum degree of enhancement of synaptic transmission. This gives rise to an optimal tuning that depends on the number of active zones. There is strong experimental evidence that astrocytes that enwrap synapses can modulate the probabilities of vesicle release through bidirectional signaling and hence regulate synaptic transmission. For low-fidelity hippocampal synapses, which typically have only one or two active zones, the predicted optimal values lie close to those determined by experimentally measured astrocytic feedback, suggesting that astrocytes optimize synaptic transmission of information

Osmosensitivity of Transient Receptor Potential Vanilloid 1 Is Synergistically Enhanced by Distinct Activating Stimuli Such as Temperature and Protons

In animals, body-fluid osmolality is continuously monitored to keep it within a narrow range around a set point (∼300 mOsm/kg). Transient receptor potential vanilloid 1 (TRPV1), a cation channel, has been implicated in body-fluid homeostasis in vivo based on studies with the TRPV1-knockout mouse. However, the response of TRPV1 to hypertonic stimuli has not been demonstrated with heterologous expression systems so far, despite intense efforts by several groups. Thus, the molecular entity of the hypertonic sensor in vivo still remains controversial. Here we found that the full-length form of TRPV1 is sensitive to an osmotic increase exclusively at around body temperature using HEK293 cells stably expressing rat TRPV1. At an ambient temperature of 24°C, a slight increase in the intracellular calcium concentration ([Ca2+]i) was rarely observed in response to hypertonic stimuli. However, the magnitude of the osmosensitive response markedly increased with temperature, peaking at around 36°C. Importantly, the response at 36°C showed a robust increase over a hypertonic range, but a small decrease over a hypotonic range. A TRPV1 antagonist, capsazepine, and a nonspecific TRP channel inhibitor, ruthenium red, completely blocked the increase in [Ca2+]i. These results endorse the view that the full-length form of TRPV1 is able to function as a sensor of hypertonic stimuli in vivo. Furthermore, we found that protons and capsaicin likewise synergistically potentiated the response of TRPV1 to hypertonic stimuli. Of note, HgCl2, which blocks aquaporins and inhibits cell-volume changes, significantly reduced the osmosensitive response. Our findings thus indicate that TRPV1 integrates multiple different types of activating stimuli, and that TRPV1 is sensitive to hypertonic stimuli under physiologically relevant conditions