6,661 research outputs found

    Wetland restoration and nitrate reduction: the example of the periurban wetland of Vitoria-Gasteiz (Basque Country, North Spain)

    Get PDF
    Changes in land use and agricultural intensification caused wetlands on the quaternary aquifer of Vitoria-Gasteiz (Basque Country) to disappear some years ago and nitrate concentration in groundwaters increased very quickly. The Basque Government recently declared the East Sector of this aquifer a Vulnerable Zone according to the 91/676/CEE European Directive. Recently, the wetlands have been restored through the closure of the main drainage ditches, the consequent elevation of the water table and the abondonment of agricultural practices near the wetlands. This is the case of the Zurbano wetland. Restoration has allowed the recovery of its biogeochemical function, which has reduced nitrate concentrations in waters. Nitrate concentrations which exceed 50 mg l–1 in groundwaters entering into the wetland are less than 10 mg l–1 at the outlet. Conditions in the wetland are conducive to the loss of nitrates: organic matter rich wetted soils, clay presence allowing a local semiconfined flow and very low hydraulic gradient. Water quality monitoring at several points around the wetland showed the processes involved in nitrate loss, although some aspects still remain unresolved. However, during storm events, the wetland effectively reduces the nitrate concentration entering the Alegria River, the most important river on the quaternary aquifer

    Link Invariants for Flows in Higher Dimensions

    Full text link
    Linking numbers in higher dimensions and their generalization including gauge fields are studied in the context of BF theories. The linking numbers associated to nn-manifolds with smooth flows generated by divergence-free p-vector fields, endowed with an invariant flow measure are computed in different cases. They constitute invariants of smooth dynamical systems (for non-singular flows) and generalizes previous results for the 3-dimensional case. In particular, they generalizes to higher dimensions the Arnold's asymptotic Hopf invariant for the three-dimensional case. This invariant is generalized by a twisting with a non-abelian gauge connection. The computation of the asymptotic Jones-Witten invariants for flows is naturally extended to dimension n=2p+1. Finally we give a possible interpretation and implementation of these issues in the context of string theory.Comment: 21+1 pages, LaTeX, no figure

    Water dynamics in a laurel montane cloud forest in the Garajonay National Park (Canary Islands, Spain)

    No full text
    International audienceField measurements from February 2003 to January 2004 in a humid (but dry in summer) crest heath wood-land (degraded laurel forest) in the National Park of Garajonay, Canary Islands (Spain), were combined to calculate water balance components. The water balance domain is at the surface of the catchment and is controlled by atmospheric processes and vegetation. This study found that annual water income (rainfall plus fog water) was 1440 mm year-1, half of which was occult (or fog) precipitation, while stand transpiration estimated from measurements of sap flow amounted, annually, to 40% of potential evapotranspiration calculated from measurements of meteorological variables. The positive role of crest laurel forests, which transpire less water than is incoming from rain and fog is emphasised. Keywords: laurel forest, fog interception, stand transpiration, sap flow, hydrological cycl

    AlineaciĂłn arqueoastronĂłmica en A Ferradura (Amoeiro-Ourense)

    Get PDF
    Presentamos un fenómeno arqueoastronómico centrado en el solsticio de invierno, novedoso en el contexto arqueológico del Noroeste peninsular. Está atestiguado mediante un petroglifo situado en el interior de un abrigo rocoso natural en un contexto arqueológico que provisionalmente consideramos como un santuario de la Segunda edad del Hierro. El estudio mediante el método comparativo de los dos petroglifos más destacados del santuario nos lleva a proponer que estamos ante la expresión material minimalista de una ideología religiosa que se expresa, con otras formas materiales, en el Estanque Monumental de Bibracte o el Capitolio de Roma. Esta ideología gira en torno a las nociones de tiempo y espacio y relaciona el orden jerárquico de la sociedad con el ritmo de la vida natural presidida por el sol

    Calendrical Deer, Time-Reckoning and landscape in Iron-Age North-West Spain

    Get PDF
    The volumen title is ASTRONOMY AND COSMOLOGY IN FOLK TRADITIONS AND CULTURAL HERITAGE Edited by Jonas Vaigkunas. Archaeologia Baltica volume 10 was prepared by KlaipÄ—da University Institute of Baltic Sea Region History and Archaeology and Museum of MolÄ—tai district. Published with a grant from the Ministry of Education and Science of The Republic of Lithuania.[EN]The relationship between petroglyphs and archaeoastronomy has been treated in several ways in the past. In the present study we examine a particular motif found among the rock carvings in the north-west of the Iberian Peninsula: a large deer with over-sized horns and an unnatural number of tips on each horn. A multidisciplinary approach combining landscape archaeology, comparative history of religions, and archaeoastronomy suggests a coherent interpretation of the motif. It reveals a unique amalgamation of calendrical motives, landscape relationships and lunisolar events. It may also be significant in relation to the Celtic world-view and its artistic manifestation, and to the relationship between time and landscape.This work is partially financed under the framework of projects P310793 `Arqueoastronomia' of the Instituto de AstrofĂ­sica de Canarias, AYA2004-01010 `Orientatio ad Sidera' of the Spanish Ministry of Education and Science, and project PGIDITO6PXIB236147PR `ArqueologĂ­a e relixiĂłn no noroeste peninsular' of the Xunta de Galicia.Peer reviewe

    An Overview of the Circular Economy among SMEs in the Basque Country: A Multiple Case Study.

    Get PDF
    Purpose: This research analyzes the maturity of environmental management as well as the degreeof to which the Circular Economy has been implemented in Basque SMEs.Design/methodology/approach:A total of 17 case studies were carried out in industrialSMEs companies in the Basque Country.Findings:The main results show that companies are limited to complying with the law and inmany cases are worried about the image of the company, although they are not committed toenvironmental issues. There is still a lot to do in SMEs, as they are the companies that face thebiggest challenges due to a lack of resources.Originality/value: Circular Economy aims to change a linear economy into promotingsustainability of the economy while also engaging in sustainable environmental protection. Thisresearch has focused on small and medium enterprises as they represent a 99% of companies inEurope and they are the ones that have the most difficulty reaching a stage of environmentalexcellence due to their limited resources

    Detecting Determinacy in Prolog Programs: 22nd International Conference, ICLP 2006, Seattle, WA, USA, August 17-20, 2006. Proceedings

    Get PDF
    In program development it is useful to know that a call to a Prolog program will not inadvertently leave a choice-point on the stack. Determinacy inference has been proposed for solving this problem yet the analysis was found to be wanting in that it could not infer determinacy conditions for programs that contained cuts or applied certain tests to select a clause. This paper shows how to remedy these serious deficiencies. It also addresses the problem of identifying those predicates which can be rewritten in a more deterministic fashion. To this end, a radically new form of determinacy inference is introduced, which is founded on ideas in ccp, that is capable of reasoning about the way bindings imposed by a rightmost goal can make a leftmost goal deterministic

    Continuous intestinal infusion of levodopa-carbidopa in patients with advanced Parkinson's disease in Spain: Subanalysis by autonomous community

    Get PDF
    Objetivos: Comparar las características de los pacientes con enfermedad de Parkinson avan- zada en tratamiento con infusión intestinal continua de levodopa-carbidopa (IICLC) y los datos de efectividad y seguridad de IICLC entre diferentes comunidades autónomas (CC. AA.). Métodos: Estudio longitudinal observacional y retrospectivo. Se incluyeron 177 pacientes de 11 CC. AA. que iniciaron tratamiento con IICLC entre enero de 2006 y diciembre de 2011. Se compararon las características clínicas y demográficas, las variables de efectividad (cambios en el tiempo OFF, ON con y sin discinesias discapacitantes, cambios en la escala de Hoehn y Yahr y puntuación de la Unified Parkinson’s Disease Rating Scale, síntomas no motores e Impresión Clínica Global) y seguridad (acontecimientos adversos), y la tasa de suspensión de IICLC. Resultados: Se hallaron diferencias significativas entre las CC. AA. en diversas variables basa- les: duración de la enfermedad hasta el inicio de IICLC, tiempo OFF (34,9-59,7%) y ON (con o sin discinesias; 2,6-48,0%), Hoehn y Yahr en ON, Unified Parkinson’s Disease Rating Scale-III en ON y OFF, presencia de ≥ 4 síntomas motores y dosis de IICLC. En el seguimiento (> 24 meses en 9 de 11 CC. AA.) hubo diferencias significativas en el porcentaje de tiempo OFF, tiempo ON sin discinesias discapacitantes, frecuencia de acontecimientos adversos e Impresión Clínica Global. La tasa de suspensión fue de entre 20-40% en todas las CC. AA., excepto en 2 (78 y 80%). Conclusiones: Este estudio muestra una amplia variabilidad en la selección de los pacientes y en la efectividad y seguridad de IICLC entre las diferentes CC. AA. Podrían influir las caracterís- ticas basales de los pacientes, la disponibilidad de un equipo multidisciplinar y la experiencia clínica.Objectives: To compare the characteristics of patients undergoing treatment with continuous intestinal infusion of levodopa-carbidopa (CIILC) for advanced Parkinson’s disease and the data on the effectiveness and safety of CIILC in the different autonomous communities (AC) of Spain. Methods: A retrospective, longitudinal, observational study was carried out into 177 patients from 11 CAs who underwent CIILC between January 2006 and December 2011. We analysed data on patients’ clinical and demographic characteristics, variables related to effectiveness (chan- ges in off time/on time with or without disabling dyskinesia; changes in Hoehn and Yahr scale and Unified Parkinson’s Disease Rating Scale scores; non-motor symptoms; and Clinical Global Impression scale scores) and safety (adverse events), and the rate of CIILC discontinuation. Results: Significant differences were observed between CAs for several baseline variables: duration of disease progression prior to CIILC onset, off time (34.9-59.7%) and on time (2.6- 48.0%; with or without disabling dyskinesia), Hoehn and Yahr score during on time, Unified Parkinson’s Disease Rating Scale-III score during both on and off time, presence of ≥ 4 motor symptoms, and CIILC dose. Significant differences were observed during follow-up (> 24 months in 9 of the 11 CAs studied) for the percentage of off time and on time without disabling dys- kinesia, adverse events frequency, and Clinical Global Impression scores. The rate of CIILC discontinuation was between 20-40% in 9 CAs (78 and 80% in remaining 2 CAs). Conclusions: This study reveals a marked variability between CAs in terms of patient selection and CIILC safety and effectiveness. These results may have been influenced by patients’ baseline characteristics, the availability of multidisciplinary teams, and clinical experience

    Quantum Magnetic Deflagration in Mn12 Acetate

    Get PDF
    We report controlled ignition of magnetization reversal avalanches by surface acoustic waves in a single crystal of Mn12 acetate. Our data show that the speed of the avalanche exhibits maxima on the magnetic field at the tunneling resonances of Mn12. Combined with the evidence of magnetic deflagration in Mn12 acetate (Suzuki et al., cond-mat/0506569) this suggests a novel physical phenomenon: deflagration assisted by quantum tunneling.Comment: 4 figure
    • …
    corecore