Interacting holographic tachyon model of dark energy

We propose a holographic tachyon model of dark energy with interaction between the components of the dark sector. The correspondence between the tachyon field and the holographic dark energy densities allows the reconstruction of the potential and the dynamics of the tachyon scalar field in a flat Friedmann-Robertson-Walker universe. We show that this model can describe the observed accelerated expansion of our universe with a parameter space given by the most recent observational results.Comment: 7 pages, 8 figures, accepted for publication in IJMP

Application of Pastoralists\u27 Knowledge to Natural Resource Management in Spain

Extensive livestock rearing has been acknowledged as an important tool for sustainable management of social-ecological systems and biodiversity conservation. In the Mediterranean Basin this relationship has been highlighted in mountainous and rural areas, where the co-evolved assemblages and dynamics of plant communities and grazing practices and patterns are mutually reinforcing. Among extensive livestock rearing systems, mobile pastoralism is a typical adaptation in semi-arid areas and mountainous regions where pasture availability is especially variable in time and space. In Spain, mobile pastoralism dates back to Neolithic and has survived until our days in different ways. An outstanding example of mobility is transhumance, an ancient pastoralist practice consisting of the seasonal migration of livestock between ecological regions following peaks in pasture productivity. Traditional ecological knowledge (TEK) can provide valuable information that complements scientific studies to improve understanding and stewardship of ecosystems. In particular, transhumance depends on the preservation, use, and transmission of TEK and the integration of TEK into land use and management policies. In this paper, we: (1) provide examples of traditional ecological knowledge related to extensive livestock rearing, and transhumance in particular, that could be useful for grasslands management; (2) explore the current challenges to the integration of this knowledge for Spanish grasslands’ management; and (3) provide insights on how these barriers might be overcome. The evidence is based on two case studies: one in the two westernmost central Pyrenean valleys of Ansó and Hecho (Aragón), where shepherds carry out short valley-mountain and middle-distance transhumance (ca. 200 km); and the other on the summer pasturelands of Montes Universales (Aragón, Guadalajara and Cuenca) from where a long-distance transhumance through the Conquense Drove Road departs (ca. 500 km). In-depth semi-structured interviews, focus groups and participant observation where applied in both cases. We conclude that much of mobile extensive stockmen’s ecological knowledge is threaten due to a lack of generational turnover, endangering the survival of a valuable source of sustainable grassland management knowledge and practices. Social and institutional barriers, including lack of profitability, dependence on EU subsidies, competition with other land-uses such as biodiversity conservation or hunting, and neglect by governments and society, negatively affect the continuity of TEK at different scales. However, some strategies, such as pastoralists’ cooperation in making their voices heard in regional and European policy decisions, or their involvement in monitoring ecological conditions of ecosystems, may foster a modest recovery of transhumance in Spain

Smelling in the dark: Phylogenomic insights into the chemosensory system of a subterranean beetle

The chemosensory system has experienced relevant changes in subterranean animals, facilitating the perception of specific chemical signals critical to survival in their particular environment. However, the genomic basis of chemoreception in cave-dwelling fauna has been largely unexplored. We generated de novo transcriptomes for antennae and body samples of the troglobitic beetle Speonomus longicornis (whose characters suggest an extreme adaptation to a deep subterranean environment) in order to investigate the evolutionary origin and diversification of the chemosensory gene repertoire across coleopterans through a phylogenomic approach. Our results suggested a diminished diversity of odourant and gustatory gene repertoires compared to polyphagous beetles that inhabit surface habitats. Moreover, S. longicornis showed a large diversity of odourant-binding proteins, suggesting an important role of these proteins in capturing airborne chemical cues. We identified a gene duplication of the ionotropic coreceptor IR25a, a highly conserved single-copy gene in protostomes involved in thermal and humidity sensing. In addition, no homologous genes to sugar receptors or the ionotropic receptor IR41a were detected. Our findings suggest that the chemosensory gene repertoire of this cave beetle may result from adaptation to the highly specific ecological niche it occupies, and that gene duplication and loss may have played an important role in the evolution of gene families involved in chemoreception. Altogether, our results shed light on the genomic basis of chemoreception in a cave-dwelling invertebrate and pave the road towards understanding the genomic underpinnings of adaptation to the subterranean lifestyle at a deeper level

PERFIL DEL USUARIO CON RETENCIÓN AGUDA DE ORINA EN UN HOSPITAL COMARCAL

During a brief lapse of time we carried out a gathering of data of all the patients who came to the Fundació Hospital Asil de Granollers (FHAG) with signs of suffering an acute retention of urine, which is the most frequent urological emergency in our service.We tried to describe the clinical profile, personal history and techniques most used in this type of patients. We carried out an observational and prospective study by means of a series of questions asked from August 1 until December 31, 2008 to the 87 visited patients.We analysed variables such as: filiation, personal history, reason for consultation and techniques carried out.An 96 % of the visited ones were males of an average age of 69 years, 63% of them had benign prostatic hyperplasia. The most frequent reason for consultation was an acute retention of urine. Nursing staff catheterized 85% and assisted 75% before being visited by the surgeon.Thanks to the information obtained in the study we created a clinical profile of the patient who comes to the Emergency Service with an acute retention of urine. The aim of these profiles was to personalize our assistance to the maximum and to know the needs that these patients present due to their pathology.Pretendemos describir el perfil clínico, antecedentes y técnicas más utilizadas en los pacientes que acuden al Servicio de Urgencias de la Fundación Hospital Asilo de Granollers (FHAG) con clínica sugestiva de retención aguda de orina (RAO). Se trata de la urgencia urológica más frecuentada en nuestro servicio.Realizamos para ello un estudio observacional y prospectivo mediante una serie de preguntas recogidas desde el 1 de agosto hasta el 31 de diciembre de 2008 en el que se incluyó a 87 pacientes visitados. Se analizaron variables tales como: filiación, antecedentes personales, motivo de consulta y técnicas llevadas a cabo.De los visitados un 96% son varones con una media de edad de 69 años, en el que un 63% tienen hipertrofia benigna de próstata (HBP), el motivo más frecuente es el de retención aguda de orina, el 85% fue sondado por enfermería y el 75% fue asistido por enfermería antes de ser visitado por el cirujano.Gracias a la información obtenida en el trabajo creamos un perfil clínico del paciente que es visitado en el servicio de urgencias con RAO con el propósito de personalizar al máximo la asistencia y conocer cuáles son las necesidades que éstos presentan debido a su patología

The Tetragnatha kauaiensis genome sheds light on the origins of genomic novelty in spider

Spiders (Araneae) have a diverse spectrum of morphologies, behaviors, and physiologies. Attempts to understand the genomic-basis of this diversity are often hindered by their large, heterozygous, and AT-rich genomes with high repeat content resulting in highly fragmented, poor-quality assemblies. As a result, the key attributes of spider genomes, including gene family evolution, repeat content, and gene function, remain poorly understood. Here, we used Illumina and Dovetail Chicago technologies to sequence the genome of the long-jawed spider Tetragnatha kauaiensis, producing an assembly distributed along 3,925 scaffolds with an N50 of ∼2 Mb. Using comparative genomics tools, we explore genome evolution across available spider assemblies. Our findings suggest that the previously reported and vast genome size variation in spiders is linked to the different representation and number of transposable elements. Using statistical tools to uncover gene-family level evolution, we find expansions associated with the sensory perception of taste, immunity, and metabolism. In addition, we report strikingly different histories of chemosensory, venom, and silk gene families, with the first two evolving much earlier, affected by the ancestral whole genome duplication in Arachnopulmonata (∼450 Ma) and exhibiting higher numbers. Together, our findings reveal that spider genomes are highly variable and that genomic novelty may have been driven by the burst of an ancient whole genome duplication, followed by gene family and transposable element expansion

Quantum cosmic models and thermodynamics

The current accelerating phase of the evolution of the universe is considered by constructing most economical cosmic models that use just general relativity and some dominating quantum effects associated with the probabilistic description of quantum physics. Two of such models are explicitly analyzed. They are based on the existence of a sub-quantum potential and correspond to a generalization of the spatially flat exponential model of de Sitter space. The thermodynamics of these two cosmic solutions is discussed, using the second principle as a guide to choose which among the two is more feasible. The paper also discusses the relativistic physics on which the models are based, their holographic description, some implications from the classical energy conditions, and an interpretation of dark energy in terms of the entangled energy of the universe.Comment: 15 pages, 1 figure, accepted for publication in Class. Quantum Gra

A dark energy multiverse

We present cosmic solutions corresponding to universes filled with dark and phantom energy, all having a negative cosmological constant. All such solutions contain infinite singularities, successively and equally distributed along time, which can be either big bang/crunchs or big rips singularities. Classicaly these solutions can be regarded as associated with multiverse scenarios, being those corresponding to phantom energy that may describe the current accelerating universe

Isolation of human fibroadipogenic progenitors and satellite cells from frozen muscle biopsies

Altres ajuts: Association Française contre les Myopathies (22525)Altres ajuts: Fundación Isabel GemioSkeletal muscle contains multiple cell types that work together to maintain tissue homeostasis. Among these, satellite cells (SC) and fibroadipogenic progenitors cells (FAPs) are the two main stem cell pools. Studies of these cells using animal models have shown the importance of interactions between these cells in repair of healthy muscle, and degeneration of dystrophic muscle. Due to the unavailability of fresh patient muscle biopsies, similar analysis of interactions between human FAPs and SCs is limited especially among the muscular dystrophy patients. To address this issue here we describe a method that allows the use of frozen human skeletal muscle biopsies to simultaneously isolate and grow SCs and FAPs from healthy or dystrophic patients. We show that while the purified SCs differentiate into mature myotubes, purified FAPs can differentiate into adipocytes or fibroblasts demonstrating their multipotency. We find that these FAPs can be immortalized and the immortalized FAPs (iFAPs) retain their multipotency. These approaches open the door for carrying out personalized analysis of patient FAPs and interactions with the SCs that lead to muscle loss