778 research outputs found

    EROSIÓN DEL SUELO EN PLANTACIONES DE CÍTRICOS EN LADERAS. VALLE DEL RIU CANYOLES, VALENCIA.

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    During the last decades the citrus orchards in the Mediterranean has moved from the lower topographical positions to the hillsides searching a free frost climatic areas. All this has been possible since the introduction of the drip-irrigation, promoted by the urban development pressure on the coastal land and valley bottoms, and fomented by the cost reduction in the groundwater pumping. The new plantations occupy now spaces of high slope angles where the losses of soil are high. In spite of the change in the location of the orchards -from plains to hillsides - the soils are being intensely ploughed or applying herbicides in order to eliminate the weeds. The conservation and organic farming agriculture can help to detain the high losses of soil. Experiments with simulated rainfall (60 mm h-1) in citrus fi elds on the Montesa’s valley (Valencia) where herbicides have been applied, on straw mulch and cash crops applied were carried out to quantify very different rates from erosion according to the applied management. The rate of erosion was negligible on the straw mulch and cash crops, meanwhile on the ploughed fi eld reached 10 g m-2 h-1, whereas in those with herbicides the loss of soil ranged between 37 and 58 g m-2 h-1.Durante las últimas décadas el cultivo de cítricos en el Mediterráneo se ha trasladado desde las zonas bajas a las laderas en busca de un mayor confort térmico. Todo ello ha sido posible por la introducción del riego localizado, potenciado por la presión urbanística de las zonas llanas, y fomentado por la reducción de costes en los bombeos de aguas subterráneas. Las nuevas plantaciones ocupan ahora espacios de elevada pendiente donde las pérdidas de suelo suelen ser graves. A pesar del cambio en la localización de los cultivos -de llanuras a laderas- se siguen laboreando intensamente los suelos y/o aplicando herbicidas con el fi n de eliminar las malas hierbas. La agricultura de conservación y la agricultura ecológica pueden ayudar a detener las elevadas pérdidas de suelo. Experimentos con lluvia simulada (60 mm h-1) en campos de cítricos del valle de Montesa (Valencia) donde se han aplicado herbicidas (residual y sistémico), laboreo, cubiertas de paja y abono verde permiten cuantifi car tasas de erosión muy distintas según el manejo aplicado. La tasa de erosión en los campos donde se aplicó la cubierta de paja y el abono verde fue nula, mientras que el campo laboreado alcanzó los 10 g m-2 h-1, y en aquellos tratados con herbicidas la pérdida de suelo osciló entre 37 y 58 g m-2 h-1

    Magneto-elastic torsional oscillations of magnetars

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    We extend a general-relativistic ideal magneto-hydrodynamical code to include the effects of elasticity. Using this numerical tool we analyse the magneto-elastic oscillations of highly magnetised neutron stars (magnetars). In simulations without magnetic field we are able to recover the purely crustal shear oscillations within an accuracy of about a few per cent. For dipole magnetic fields between 5 x 10^13 and 10^15 G the Alfv\'en oscillations become modified substantially by the presence of the crust. Those quasi-periodic oscillations (QPOs) split into three families: Lower QPOs near the equator, Edge QPOs related to the last open field line and Upper QPOs at larger distance from the equator. Edge QPOs are called so because they are related to an edge in the corresponding Alfv\'en continuum. The Upper QPOs are of the same kind, while the Lower QPOs are turning-point QPOs, related to a turning point in the continuous spectrum.Comment: 6 pages, 1 figure, 1 table, Proceedings of NEB14, to appear in J. Phys.: Conf. Se

    Guiding signs in metabolic disease diagnosis

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    Los errores innatos del metabolismo son un grupo de enfermedades genéticas con sintomatología muy inespecífica y por tanto difícil diagnóstico si no existe una sospecha clínica elevada. Sin embargo existen algunos datos de la exploración física y de las pruebas complementarias que pueden enfocar el proceso diagnóstico hacia la solicitud de pruebas específicas que lo confirmen. El caso que presentamos trata de destacar algunos de estos datos que pueden hacer sospechar la existencia de un defecto congénito de la glucosilación de proteínas, trastorno infrecuente pero con algunas formas tratables, por lo que su sospecha y diagnóstico precoz es de vital importanciaInborn errors of metabolism are a group of genetic diseases with non specific symptoms and therefore difficult to diagnose without high clinical suspicion. However there are some physical examination data and laboratory tests that can focus the diagnostic process to the implementation of specific tests to confirm them. The case exposed highlights some of these data that can make us suspect the existence of a congenital defect of glycosylation of proteins, rare disorder but with some treatable variations, that make their suspicion and early diagnosis of great importanc

    Study of paediatric patients with the clinical and biochemical phenotype of glucose transporter type 1 deficiency syndrome.

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    [ES] Introducción El síndrome de déficit del transportador de glucosa cerebral (GLUT1DS) puede presentar fenotipos variados, incluyendo epilepsia, déficit intelectual y trastorno del movimiento. La mayoría presenta hipoglucorraquia y/o defectos en el gen SLC2A1, aunque existen pacientes sin hipoglucorraquia y otros con genética de SLC2A1-negativa, o con defectos en otros genes y fenotipo compatible. Objetivos Describir las características clínicas, bioquímicas y genéticas y realizar un análisis univariante de un grupo de pacientes con fenotipo clínico y bioquímico de GLUT1DS, con o sin genética SLC2A1-positiva. Material y métodos Se incluyeron 13 pacientes con criterios clínico-bioquímicos de GLUT1DS. Se realizó secuenciación de SLC2A1 y MLPA. En los casos negativos se realizó exoma clínico. Resultados Seis presentaron fenotipo clásico, 2 discinesia paroxística, 2 trastornos del movimiento complejo, 2 ausencias precoces y otro presentó epilepsia con ausencias infantiles refractaria a farmacoterapia. Seis fueron SLC2A1-positivos. Y en 5 de los SLC2A1-negativos se identificó otro defecto genético. No hubo diferencias significativas entre los dos grupos en edad de inicio, presentación clínica, microcefalia, discapacidad intelectual ni respuesta a dieta cetogénica. De forma no significativa, los pacientes SCL2A1-positivos presentaron más cambios clínicos en relación con la ingesta (66,7% vs. 28,6%) y mayor persistencia de síntomas motores (66% vs. 28,6%). De forma significativa, presentaron menor glucorraquia (34,5 mg/dl vs. 46 mg/dl, p = 0,04) e índice glucorraquia/glucemia más bajo (0,4 vs. 0,48, p = 0,05) que los SLC2A1-negativos. Conclusiones GLUT1DS puede ser causado por defectos genéticos en otros genes diferentes de SLC2A1 en pacientes con fenotipo compatible, hipoglucorraquia y buena respuesta a dieta cetogénica. [EN] Introduction Glucose transporter type 1 (GLUT1) deficiency syndrome may present a range of phenotypes, including epilepsy, intellectual disability, and movement disorders. The majority of patients present low CSF glucose levels and/or defects in the SLC2A1 gene; however, some patients do not present low CSF glucose or SLC2A1 mutations, and may have other mutations in other genes with compatible phenotypes. Aims We describe the clinical, biochemical, and genetic characteristics of the disease and perform a univariate analysis of a group of patients with clinical and biochemical phenotype of GLUT1 deficiency syndrome, with or without SLC2A1 mutations. Material and methods The study included 13 patients meeting clinical and biochemical criteria for GLUT1 deficiency syndrome. SLC2A1 sequencing and multiplex ligation-dependent probe amplification were performed; exome sequencing was performed for patients with negative results. Results Six patients presented the classic phenotype; 2 paroxysmal dyskinesia, 2 complex movement disorders, 2 early-onset absence seizures, and one presented drug-resistant childhood absence epilepsy. Six patients were positive for SLC2A1 mutations; in the other 5, another genetic defect was identified. No significant differences were observed between the 2 groups for age of onset, clinical presentation, microcephaly, intellectual disability, or response to ketogenic diet. Patients with SLC2A1 mutations presented more clinical changes in relation to diet (66.7% vs. 28.6% in the SLC2A1-negative group) and greater persistence of motor symptoms (66% vs. 28.6%); these differences were not statistically significant. Significant differences were observed for CSF glucose level (34.5 vs. 46 mg/dL, P = .04) and CSF/serum glucose ratio (0.4 vs. 0.48, P < .05).S

    First-principles modelling of molecular single-electron transistors

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    We present a first-principles method for calculating the charging energy of a molecular single-electron transistor operating in the Coulomb blockade regime. The properties of the molecule are modeled using density-functional theory, the environment is described by a continuum model, and the interaction between the molecule and the environment are included through the Poisson equation. The model is used to calculate the charge stability diagrams of a benzene and C60_{60} molecular single-electron transistor

    Inter-specific aggression generates ant mosaics in canopies of primary tropical rainforest

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    The ant mosaic is a concept of the non-random spatial distribution of individual ant species in trees built upon the assumption of interspecific behavioural associations. However, colony identity and environmental variance may also play a role in species distribution. Here we assess the presence of ant mosaics in a primary forest ecosystem and whether they are structured by species' aggressive behaviours or by habitat filtering. We sampled arboreal ants from vertically stratified baits exposed in 225 canopy trees in a 9-ha plot of primary lowland forest in Papua New Guinea, the largest forest area surveyed to detect ant mosaics. We performed behavioural tests on conspecific ants from adjacent trees to determine the territories of individual colonies. We explored the environmental effects on the ant communities using information on the plot vegetation structure and topography. Furthermore, we created a novel statistical method to test for the community non-random spatial structure across the plot via spatial randomisation of individual colony territories. Finally, we linked spatial segregation among the four most common species to experimentally assessed rates of interspecies aggression. The ant communities comprised 57 species of highly variable abundance and vertical stratification. Ant community composition was spatially dependent, but it was not affected by tree species composition or canopy connectivity. Only local elevation had a significant but rather small effect. Individual colony territories ranged from one tree to 0.7 ha. Species were significantly over-dispersed, with their territory overlap significantly reduced. The level of aggression between pairs of the four most common species was positively correlated with their spatial segregation. Our study demonstrates the presence of ant mosaics in tropical pristine forest, which are maintained by interspecific aggression rather than habitat filtering, with vegetation structure having a rather small and indirect effect, probably linked to microclimate variability.publishedVersio

    Estudio de pacientes pediátricos con fenotipo clínico y bioquímico de síndrome de déficit de transportador de glucosa cerebral (GLUT-1)

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    [EN] Introduction: Glucose transporter type 1 (GLUT1) deficiency syndrome may present a range of phenotypes, including epilepsy, intellectual disability, and movement disorders. The majority of patients present low CSF glucose levels and/or defects in the SLC2A1 gene; however, some patients do not present low CSF glucose or SLC2A1 mutations, and may have other mutations in other genes with compatible phenotypes. Aims: We describe the clinical, biochemical, and genetic characteristics of the disease and perform a univariate analysis of a group of patients with clinical and biochemical phenotype of GLUT1 deficiency syndrome, with or without SLC2A1 mutations. Material and methods: The study included 13 patients meeting clinical and biochemical criteria for GLUT1 deficiency syndrome. SLC2A1 sequencing and multiplex ligation-dependent probe amplification were performed; exome sequencing was performed for patients with negative results. Results: Six patients presented the classic phenotype; 2 paroxysmal dyskinesia, 2 complex movement disorders, 2 early-onset absence seizures, and one presented drug-resistant childhood absence epilepsy. Six patients were positive for SLC2A1 mutations; in the other 5, another genetic defect was identified. No significant differences were observed between the 2 groups for age of onset, clinical presentation, microcephaly, intellectual disability, or response to ketogenic diet. Patients with SLC2A1 mutations presented more clinical changes in relation to diet (66.7%, vs 28.6% in the SLC2A1-negative group) and greater persistence of motor symptoms (66% vs 28.6%); these differences were not statistically significant. Significant differences were observed for CSF glucose level (34.5 vs 46mg/dL, P=.04) and CSF/serum glucose ratio (0.4 vs 0.48, P<.05). Conclusions: GLUT1 deficiency syndrome may be caused by mutations to genes other than SLC2A1 in patients with compatible phenotype, low CSF glucose level, and good response to the ketogenic diet. [ES] Introducción: El síndrome de déficit del transportador de glucosa cerebral (GLUT1DS) puede presentar fenotipos variados, incluyendo epilepsia, déficit intelectual y trastorno del movimiento. La mayoría presentan hipoglucorraquia y/o defectos en el gen SLC2A1, aunque existen pacientes sin hipoglucorraquia y otros con genética de SLC2A1-negativa, o con defectos en otros genes y fenotipo compatible. Objetivos: Describir las características clínicas, bioquímicas y genéticas y realizar un análisis univariante de un grupo de pacientes con fenotipo clínico y bioquímico de GLUT1DS, con o sin genética SLC2A1-positiva. Material y métodos: Se incluyeron 13 pacientes con criterios clínico-bioquímicos de GLUT1DS. Se realizó secuenciación de SLC2A1 y MLPA. En los casos negativos se realizó exoma clínico. Resultados: Seis presentaron fenotipo clásico, 2 discinesia paroxística, 2 trastornos del movimiento complejo, 2 ausencias precoces y otro presentó epilepsia con ausencias infantiles refractaria a farmacoterapia. Seis fueron SLC2A1-positivos. Y en 5 de los SLC2A1-negativos se identificó otro defecto genético. No hubo diferencias significativas entre los dos grupos en edad de inicio, presentación clínica, microcefalia, discapacidad intelectual ni respuesta a dieta cetogénica. De forma no significativa, los pacientes SCL2A1-positivos presentaron más cambios clínicos en relación con la ingesta (66,7% vs. 28,6%) y mayor persistencia de síntomas motores (66% vs. 28,6%). De forma significativa, presentaron menor glucorraquia (34,5 mg/dl vs. 46 mg/dl, p = 0.04) e índice glucorraquia/glucemia más bajo (0,4 vs. 0,48, p = 0,05) que los SLC2A1-negativos. Conclusiones: GLUT1DS puede ser causado por defectos genéticos en otros genes diferentes de SLC2A1 en pacientes con fenotipo compatible, hipoglucorraquia y buena repuesta a dieta cetogénica.‘‘Identification and clinical and biochemical characterisation of patients with GLUT1DS: treatment monitoring.’’ Translational research project 2017, CIBERER. Coordinator: Dr Luis González Gutiérrez-Solana (GCV6). Participating units: U703 (Artuch); U746 (Pérez); GCV5 (Couce); GCV6 (Gutiérrez-Solana); GCV7 (López Laso); GCV8 (del Toro). Research project: hereditary metabolic disorders.S

    Recognition and Stigma of Prescription Drug Abuse Disorder: Personal and Community Determinants

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    Background Prescription drug abuse (PDA) disorders continue to contribute to the current American opioid crisis. Within this context, our study seeks to improve understanding about stigma associated with, and symptom recognition of, prescription drug abuse. Aims Model the stigma and symptom recognition of PDA in the general population. Methods A randomized, nation-wide, online, vignette-focused survey of the general public (N = 631) was implemented with an oversample for rural counties. Logit estimation was used for analysis, with regional and county-level sociodemographic variables as controls. Results Individual respondents that self-identify as having or having had “a prescription drug abuse issue” were less likely to correctly identify the condition and were 4 times more likely to exhibit stigma. Male respondents were approximately half as likely to correctly identify PDA as female respondents while older respondents (55+) were more likely to correctly identify PDA, relative to those aged 35–54. Being both male and younger was associated with slightly more stigma, in that they were less likely to disagree with the stigma statement. Conclusions In light of the continued risks that individuals with PDA behaviors face in potentially transitioning to illicit opioid use, the findings of this survey suggested a continued need for public education and outreach. Of particular note is the perspective of those who have self-identified with the condition, as this population faces the largest risks of adverse health outcomes from illicit drug use within the survey respondents

    Family ties: Maternal-offspring attachment and young adult nonmedical prescription opioid use

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    Background: Nonmedical prescription drug use is prevalent among young adults, yet little is known about modifiable determinants of use. We examined whether maternal-offspring attachment reported at mean age 21 was associated with nonmedical prescription opioid use at mean age 26, and investigated whether a history of depressive symptoms and substance use played a role in associations between maternal-offspring attachment and nonmedical prescription opioid use. Methods: We used data from the Growing Up Today Study, a longitudinal cohort of United States adolescents followed into young adulthood. Maternal-offspring attachment was reported by young adults and their mothers, and defined as mutual low, mutual medium or high, and dissonant. Analyses were carried out in the full sample using generalized estimating equation models, and in a sibling subsample, using conditional fixed effects models to control for stable aspects of the family environment. Results: Analyses with the full sample and the sibling subsample both showed that mutual medium/high maternal-offspring attachment at age 21 was associated with lower odds of nonmedical prescription opioid use at age 26 (RR = 0.74; 95% CI = 0.57–0.97 in full sample). The association was partly mediated by mean age 23 offspring smoking, heavy episodic drinking, and illicit drug use. Conclusions: Promoting reciprocal attachment in the maternal-offspring dyad should be investigated as a strategy to prevent nonmedical prescription opioid use by young adulthood. Even in young adulthood, programs that target both parents and offspring may have greater impact on offspring substance use than programs that target offspring alone
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