321 research outputs found
Effects of Livestock Grazing on the Shrub Vegetation Biomass in the ‘Sierra de Guara’ Natural Park (Spain)
The \u27Sierra de Guara\u27 Natural Park (80.7 Kha) is a Mediterranean mountain area in Huesca, south of the Spanish Pyrenees. Shrub and forest pastures dominate the Park. They are grazed mainly by sheep, but also by suckler cattle and goats. Average stocking rate is 0.15 LU/ha. As in other European mountain areas, agricultural activities have declined during the last few decades. This has caused a process of secondary vegetation succession towards shrub invasion, with consequent landscape changes. This study aimed to quantify the effect of grazing on shrub vegetation biomass
Assessing the potential of the dart model to discrete return lidar simulation—application to fuel type mapping
Fuel type is one of the key factors for analyzing the potential of fire ignition and propaga-tion in agricultural and forest environments. The increase of three-dimensional datasets provided by active sensors, such as LiDAR (Light Detection and Ranging), has improved the classification of fuel types through empirical modelling. Empirical methods are site and sensor specific while Radiative Transfer Models (RTM) approaches provide broader universality. The aim of this work is to analyze the suitability of Discrete Anisotropic Radiative Transfer (DART) model to replicate low density small-footprint Airborne Laser Scanning (ALS) measurements and subsequent fuel type classification. Field data measured in 104 plots are used as ground truth to simulate LiDAR response based on the sensor and flight characteristics of low-density ALS data captured by the Spanish National Plan for Aerial Orthophotography (PNOA) in two different dates (2011 and 2016). The accuracy assessment of the DART simulations is performed using Spearman rank correlation coefficients between the simulated metrics and the ALS-PNOA ones. The results show that 32% of the computed metrics overpassed a correlation value of 0.80 between simulated and ALS-PNOA metrics in 2011 and 28% in 2016. The highest correlations were related to high height percentiles, canopy variability metrics as for example standard deviation and Rumple diversity index, reaching correlation values over 0.94. Two metric selection approaches and Support Vector Machine classification method with variants were compared to classify fuel types. The best-fitted classification model, trained with the DART simulated sample and validated with ALS-PNOA data, was obtained using Support Vector Machine method with radial kernel. The overall accuracy of the classification after validation was 88% and 91% for the 2011 and 2016 years, respectively. The use of DART demonstrates its value for simulating generalizable 3D data for fuel type classification providing relevant information for forest managers in fire prevention and extinction
Las redes sociales de la economía social
A partir del trabajo de campo en curso llevado a cabo en Cataluña (proyecto de investigación ENCLAVE - CSO2012-32635), se sugiere la existencia de al menos tres tipos de los llamados "empresarios sociales": los profesionales desplazados por los recortes en el gasto público en los sectores de la salud, los servicios sociales y la cooperación; las cooperativas y las asociaciones tradicionales, re-etiquetados como "empresarios sociales" o "empresas sociales" (conversos) y, por último, los que gozan de apoyo institucional público y privado para el desarrollo de sus iniciativas sociales o ambientales (elegidos). Con el fin de contrastar algunas de las hipótesis que plantea la literatura sobre los emprendedores sociales (a saber, su capacidad para movilizar recursos locales y lograr la participación de una amplia gama de actores para el logro de sus fines), se recogieron redes personales de casos de emprendedores sociales con la ayuda de EgoNet (http:// sourceforge.net/projects/egonet) utilizando un generador múltiple de nombres para obtener datos sobre personas relacionadas con la iniciativa. Las redes personales de estos tres tipos se resumieron mediante "grafos agrupados"(http://visone.info/wiki/index.php/Personal_networks_%28tutorial%29, los cuales presentan diferentes características para cada tipo, en términos de equilibrio entre lazos fuertes y débiles de apoyo a la iniciativa empresarial. Sostenemos que este nuevo escenario en el que nuevos y viejos actores se esfuerzan por presentarse a sí mismos con las etiquetas disponibles difícilmente puede entenderse sólo en términos de las motivaciones sociales, como sugiere la literatura. Por último, se presenta una conceptualización del campo del "empresariado social" como consecuencia del avance del neoliberalismo y la reducción del gasto público destinado a las clases medias y populares en Europa a partir de la crisis financiera
Development of criteria applicable to bacteriological quality control of the waters in mollusc producing areas of Santander Bay
European Union regulations (Directive 79/923/CEE) do not establish any quality criteria guidelines with regard to the concentration of bacteriological indicators in the water for monitoring shellfish growing areas. In the present study the bioconcentration factor of fecal coliforms in molluscs is analysed. With these results, we have estimated an average bioconcentration factor of 10. Based on these values, we propose the establishment of a complementary bacteriological water quality criteria for shellfish growing areas, and modifications in their regulatory environmental monitoring programmes.La normativa de la Unión Europea (Directiva 79/923/CEE) no establece ningún criterio de calidad referente a la concentración de indicadores bacteriológicos en el agua para la vigilancia ambiental de las zonas de producción de moluscos. En este estudio se planteó el análisis del factor de bioconcentración de coliformes fecales en los moluscos. Los resultados obtenidos permiten estimar un factor medio de bioconcentración de 10, a partir del cual se desarrolla un sistema complementario de control de la calidad bacteriológica de las aguas en el entorno de las zonas de producción. Tomando como base estos resultados, se propone una adaptación de los programas de vigilancia y control ambiental establecidos en la normativa para estas zonas.Instituto Español de Oceanografí
Galectin-3 shapes toxic alpha-synuclein strains in Parkinson's disease.
Parkinson's Disease (PD) is a neurodegenerative and progressive disorder characterised by intracytoplasmic inclusions called Lewy bodies (LB) and degeneration of dopaminergic neurons in the substantia nigra (SN). Aggregated α-synuclein (αSYN) is known to be the main component of the LB. It has also been reported to interact with several proteins and organelles. Galectin-3 (GAL3) is known to have a detrimental function in neurodegenerative diseases. It is a galactose-binding protein without known catalytic activity and is expressed mainly by activated microglial cells in the central nervous system (CNS). GAL3 has been previously found in the outer layer of the LB in post-mortem brains. However, the role of GAL3 in PD is yet to be elucidated. In post-mortem samples, we identified an association between GAL3 and LB in all the PD subjects studied. GAL3 was linked to less αSYN in the LB outer layer and other αSYN deposits, including pale bodies. GAL3 was also associated with disrupted lysosomes. In vitro studies demonstrate that exogenous recombinant Gal3 is internalised by neuronal cell lines and primary neurons where it interacts with endogenous αSyn fibrils. In addition, aggregation experiments show that Gal3 affects spatial propagation and the stability of pre-formed αSyn fibrils resulting in short, amorphous toxic strains. To further investigate these observations in vivo, we take advantage of WT and Gal3KO mice subjected to intranigral injection of adenovirus overexpressing human αSyn as a PD model. In line with our in vitro studies, under these conditions, genetic deletion of GAL3 leads to increased intracellular αSyn accumulation within dopaminergic neurons and remarkably preserved dopaminergic integrity and motor function. Overall, our data suggest a prominent role for GAL3 in the aggregation process of αSYN and LB formation, leading to the production of short species to the detriment of larger strains which triggers neuronal degeneration in a mouse model of PD
The Absence of Caspase-8 in the Dopaminergic System Leads to Mild Autism-like Behavior
In the last decade, new non-apoptotic roles have been ascribed to apoptotic caspases. This family of proteins plays an important role in the sculpting of the brain in the early stages of development by eliminating excessive and nonfunctional synapses and extra cells. Consequently, impairments in this process can underlie many neurological and mental illnesses. This view is particularly relevant to dopamine because it plays a pleiotropic role in motor control, motivation, and reward processing. In this study, we analyze the effects of the elimination of caspase-8 (CASP8) on the development of catecholaminergic neurons using neurochemical, ultrastructural, and behavioral tests. To do this, we selectively delete the CASP8 gene in cells that express tyrosine hydroxylase with the help of recombination through the Cre-loxP system. Our results show that the number of dopaminergic neurons increases in the substantia nigra. In the striatum, the basal extracellular level of dopamine and potassium-evoked dopamine release decreased significantly in mice lacking CASP8, clearly showing the low dopamine functioning in tissues innervated by this neurotransmitter. This view is supported by electron microscopy analysis of striatal synapses. Interestingly, behavioral analysis demonstrates that mice lacking CASP8 show changes reminiscent of autism spectrum disorders (ASD). Our research reactivates the possible role of dopamine transmission in the pathogenesis of ASD and provides a mild model of autism
Physical exercise neuroprotects ovariectomized 3xTg-AD mice through BDNF mechanisms
Postmenopausal women may be more vulnerable to cognitive loss and Alzheimer's disease (AD) than premenopausal women because of their deficiency in estrogens, in addition to their usually older age. Aerobic physical exercise has been proposed as a therapeutic approach for maintaining health and well-being in postmenopausal women, and for improving brain health and plasticity in populations at high risk for AD. To study the neuroprotective mechanisms of physical exercise in a postmenopausal animal model, we submitted previously ovariectomized, six-month old non-transgenic and 3xTg-AD mice to three months of voluntary exercise in a running wheel. At nine months of age, we observed lower grip strength and some exacerbation of the behavioral and psychological symptoms of dementia (BPSD)-like involving active exploratory activities. A similar major cognitive impairment was observed of ovariectomized 3xTg-AD mice in comparison with sham-operated 3xTg-AD mice. A reduction of bodily fitness and lack of retention of memory were observed in the ovariectomized non-transgenic mice. Physical exercise protected against all deleterious behaviors and normalized learning and memory. It also protected against body frailty, as expected. Analyses of hippocampal key markers of antioxidant and neuroplasticity signaling pathways, showed that ovariectomy impairs the activation of CREB through physical exercise. Furthermore, molecular and behavioral correlates suggested a central role of BDNF in the neuroprotection mediated by physical exercise therapy against apathy and memory loss induced by ovariectomy and the AD-genotype. © 2014 Elsevier Ltd.This study was supported by grants: SAF2009-13093-C02-02, SAF2010-19498, SAF2012-39852-C02-02 and CSD2010-00045 from the Spanish MINECO; 2009/SGR/214 from the Generalitat and 062931 from the Fundació La Marató de TV3, of Catalonia; and 35NEURO GentxGent. Yoelvis García-Mesa acknowledges support received from the Fundació La Marató de TV3Peer Reviewe
High-resolution melting assay for genotyping variants of the CYP2C19 enzyme and predicting voriconazole effectiveness
Voriconazole is a triazole antifungal agent recommended as primary treatment for invasive aspergillosis, as well as some other mold infections. However, it presents some pharmacokinetic singularities that lead to a great variability intra- and interindividually, nonlinear pharmacokinetics, and a narrow therapeutic range. Most experts have recommended tracing the levels of voriconazole in patients when receiving treatment. This azole is metabolized through the hepatic enzyme complex cytochrome P450 (CYPP450), with the isoenzyme CYP2C19 being principally involved. Allelic variations (polymorphisms) of the gene that encodes this enzyme are known to contribute to variability in voriconazole exposure. Three different allelic variants, CYP2C19*17, CYP2C19*2, and CYP2C19*3, could explain most of the phenotypes related to the voriconazole metabolism and some of its pharmacokinetic singularities. We designed a rapid molecular method based on high-resolution melting to characterize these polymorphisms in a total of 142 samples, avoiding sequencing. Three PCRs were designed with similar cycling conditions to run simultaneously. The results showed that our method represents a fast, accurate, and inexpensive means to study these variants related to voriconazole metabolism. In clinical practice, this could offer a useful tool to individually optimize therapy and reduce expenses in patients with fungal infections.National Institute of Health Carlos III (AES13PI13/01817Research Project MPY 1367/13). L.B.-M. has a contract supported by theMinisterio de Ciencia e Innovación, Instituto de Salud Carlos III, cofinanced by the EuropeanDevelopment Regional Fund (EDRF) “A Way to Achieve Europe” and the SpanishNetwork for the Research in Infectious Diseases (REIPI; RD12/0015/0015). B.M.-R. is astudent in the Master’s Program entitled “Microbiología Aplicada a la Salud Pública eInvestigación en Enfermedades Infecciosas,” Alcalá de Henares University, Madrid,Spain. A.C. and C.C. were supported by the Northern Portugal Regional OperationalProgram (NORTE 2020) under the Portugal 2020 Partnership Agreement through theEuropean Regional Development Fund (FEDER; NORTE-01-0145-FEDER-000013) and theFundação Para a Ciência e Tecnologia (FCT; IF/00735/2014 [A.C.] and SFRH/BPD/96176/2013 [C.C.])
Arginine deprivation alters microglial polarity and synergizes with radiation to eradicate non-arginine-auxotrophic glioblastoma tumors
New approaches for the management of glioblastoma (GBM) are an urgent and unmet clinical need. Here, we illustrate that
the efficacy of radiotherapy for GBM is strikingly potentiated by concomitant therapy with the arginine-depleting agent
ADI-PEG20 in a non-arginine-auxotrophic cellular background (argininosuccinate synthetase 1 positive). Moreover, this
combination led to durable and complete radiological and pathological response, with extended disease-free survival in
an orthotopic immune-competent model of GBM, with no significant toxicity. ADI-PEG20 not only enhanced the cellular
sensitivity of argininosuccinate synthetase 1–positive GBM to ionizing radiation by elevated production of nitric oxide (˙NO)
and hence generation of cytotoxic peroxynitrites, but also promoted glioma-associated macrophage/microglial infiltration
into tumors and turned their classical antiinflammatory (protumor) phenotype into a proinflammatory (antitumor)
phenotype. Our results provide an effective, well-tolerated, and simple strategy to improve GBM treatment that merits
consideration for early evaluation in clinical trials.Fondo de Desarrollo Regional (FEDER). Programa Operativo Epiro 2014-2020National Strategic Reference Frameworks de la Unión Europea. NSRF 2014-2020-5033092Ministerio de Ciencia, Innovación y Universidades de España y fondos FEDER. RTI2018-098645-B-100Consejería de Economía y Conocimiento de la Junta de Andalucía y fondos FEDER. P18- RT-1372Universidad de Sevilla. US-126480
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