974 resultados para 1857-10-21
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Se cuenta la experiencia desarrollada en un centro educativo en la que el alumnado resuelve problemas matem??ticos relacionados con el contexto del centro de forma sistem??tica. Se trata de trabajar esta materia de manera creativa, como un reto de ingenio y destreza mental, donde los protagonistas de los enunciados son el alumnado, el personal docente, el vecindario, etc. Se insiste en la elaboraci??n de un procedimiento a seguir para la resoluci??n de los problemas, ya que se observa un gran d??ficit en el alumnado para la b??squeda de estrategias adecuadas que den soluci??n a los mismos.
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La tesi es planteja en quina mesura l'estructura de la xarxa social existent en un districte turístic entre els diferents actors que la conformen, i la posició que aquests ocupen en la mateixa, afecta a la estacionalitat de la demanda hotelera del districte. S'assumeix que els fluxos d'informació i coneixement entre els actors del districte, i també entre aquests i d'altres actors externs determinaran la seva capacitat d'innovació, i per tant, la seva capacitat de creació de nous productes i ofertes turístiques capaces d'atraure turistes fora de la temporada alta. Així, es pretén analitzar si els hotels millor posicionats dins de l'estructura de relacions d'un districte turístic d'àmbit comarcal es corresponen amb els que presenten una millor estacionalitat en termes d'allargament de la temporada, de mesos d'obertura i de millora de l'ocupació en els dos darrers períodes. Addicionalment, s'analitza en quina mesura els segments de mercat turístic als que els hotels dirigeixen els seus esforços expliquen les diferencies d'estacionalitat entre ells.
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The research has explored the reality of generational renewal in agriculture in order to understand the entry process, the agricultural practices of young people and their attitudes toward a new agrosocial paradigm. The methodology combined qualitative and quantitative techniques based on a comparative analysis between Southern Ontario (Canada) and Catalonia (Spain). The first result is that the pathway to become a farmer is a process consisting of different phases where each profile shows different needs and abilities. The second result verifies how the practices and attitudes of young people vary depending on the family origin. The thesis also analyzes the most relevant results in policy terms. Finally the research shows the reality of an emerging group of young farmers who put in practice a new agrosocial paradigm. This group is made up by continuers and newcomers and we have called them "New peasantry".
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Un pont de dihidrogen (dihydrogen bond,DHB) és un tipus de pont d'hidrogen atípic que s'estableix entre un hidrur metàl·lic i un donador de protons com un grup OH o NH. Els ponts de dihidrogen són claus en les característiques geomètriques i altres propietats de compostos que en presenten tan de molècules petites com el dímer de NH3BH3, com d'estructures superiors més complicades com complexes metàl·lics o sòlids. Poden ser útils aplicats a certes molècules o síntesis moleculars per a obtenir nous materials amb propietats o característiques fetes a mida. El treball d'aquesta tesi està orientat a millorar la comprensió dels ponts de dihidrogen, aprofundint en certs aspectes de la seva naturalesa atòmica/molecular utilitzant mètodes teòrics basats en la química física quàntica.
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453 p.
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El presente ensayo pretende hacer un análisis sociojurídico de la presunción de derecho nemini licet ignorare jus, cuya existencia en el ámbito del derecho penal moderno ha sido cuestionada, debatida y en algunos casos excluida. Para identificar las posibles causas que vuelven ineficaz a dicha presunción, se realiza un abordaje desde tres enfoques diversos pero complementarios. Primero, desde un enfoque fáctico en el que se cuestiona la utilidad real de la presunción en el ámbito penal y sus limitaciones pragmáticas. Segundo, desde un enfoque sociológico en el cual se analizan los principales conflictos sociales originados con la vigencia de dicha presunción. En un tercer momento se realiza un análisis de carácter jurídico que muestra la incompatibilidad de dicha presunción con el sistema constitucional de derechos y justicia vigente en el Ecuador. Finalmente, se hace una reflexión sobre los puntos abordados y se busca justificar la exclusión de dicha presunción de la legislación penal ecuatoriana, dejando para el debate otros elementos que junto con la diversidad cultural deben incluirse en el error de prohibición.
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We introduce a technique for assessing the diurnal development of convective storm systems based on outgoing longwave radiation fields. Using the size distribution of the storms measured from a series of images, we generate an array in the lengthscale-time domain based on the standard score statistic. It demonstrates succinctly the size evolution of storms as well as the dissipation kinematics. It also provides evidence related to the temperature evolution of the cloud tops. We apply this approach to a test case comparing observations made by the Geostationary Earth Radiation Budget instrument to output from the Met Office Unified Model run at two resolutions. The 12km resolution model produces peak convective activity on all lengthscales significantly earlier in the day than shown by the observations and no evidence for storms growing in size. The 4km resolution model shows realistic timing and growth evolution although the dissipation mechanism still differs from the observed data.
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Aim. The aim of this study was to investigate whether a single soccer specific fitness test (SSFT) could differentiate between highly trained and recreationally active soccer players in selected test performance indicators. Methods. Subjects: 13 Academy Scholars (AS) from a professional soccer club and 10 Recreational Players (RP) agreed to participate in this study. Test 1-(V)over dotO(2) max was estimated from a progressive shuttle run test to exhaustion. Test 2-The SSFT was controlled by an automated procedure and alternated between walking, sprinting, jogging and cruise running speeds. Three activity blocks (1A, 2A and 3A) were separated by 3 min rest periods in which blood lactate samples were drawn. The 3 blocks of activity (Part A) were followed by 10 min of exercise at speeds alternating between jogging and cruise running (Part B). Results. Estimated (V)over dotO(2) max did not significantly differ between groups, although a trend for a higher aerobic capacity was evident in AS (p<0.09). Exercising heart rates did not differ between AS and RP, however, recovery heart rates taken from the 3 min rest periods were significantly lower in AS compared with RP following blocks 1A (124.65 b(.)min(-1) +/-7.73 and 133.98 b(.)min(-1) +/-6.63), (p<0.05) and 3A (129.91 b.min(-1) +/-10.21 and 138.85 b.min(-1) +/-8.70), (p<0.01). Blood lactate concentrations were significantly elevated in AS in comparison to RP following blocks 2A (6.91 mmol(.)l(-1) +/-2.67 and 4.74 mmol(.)l(-1) +/-1.28) and 3A (7.18 mmol(.)l(-1) +/-2.97 and 4.88 mmol(.)l(-1) +/-1.50), (p<0.05). AS sustained significantly faster average sprint times in block 3A compared with RP (3.18 sec +/-0.12 and 3.31 sec +/-0.12), (p<0.05). Conclusion. The results of this study show that highly trained soccer players are able to sustain, and more quickly recover from, high intensity intermittent exercise.
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Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis) campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO2 by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE) and total peroxy radicals (RO2* = HO2+ΣRO2, R = organic chain) by two similar instruments based on the peroxy radical chemical amplification (PeRCA) technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO2, NOy, O3 and a wider range of VOCs were collected simultaneously. Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO2* data available agree quite reasonably within the instrumental errors. The [RO2*]/[HO2] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.
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We introduce the perspex machine which unifies projective geometry and the Turing machine, resulting in a supra-Turing machine. Specifically, we show that a Universal Register Machine (URM) can be implemented as a conditional series of whole numbered projective transformations. This leads naturally to a suggestion that it might be possible to construct a perspex machine as a series of pin-holes and stops. A rough calculation shows that an ultraviolet perspex machine might operate up to the petahertz range of operations per second. Surprisingly, we find that perspex space is irreversible in time, which might make it a candidate for an anisotropic spacetime geometry in physical theories. We make a bold hypothesis that the apparent irreversibility of physical time is due to the random nature of quantum events, but suggest that a sum over histories might be achieved by sampling fluctuations in the direction of time flow. We propose an experiment, based on the Casimir apparatus, that should measure fluctuations of time flow with respect to time duration- if such fluctuations exist.
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Biomaterials are often soft materials. There is now growing interest in designing, synthesizing and characterising soft materials that mimic the properties of biological materials such as tissue, proteins, DNA or cells. Research on biomimetic soft matter is therefore a developing theme with important emerging applications in biomedicine including tissue engineering, diagnostics, gene therapy, drug delivery and many others. There are also important basic science questions concerning the use of concepts from colloid and polymer science to understand the self-assembly of biomimetic soft materials. This issue of Soft Matter presents a selection of extremely topical articles on a diversity of biomimetic soft matter systems. I thank the contributors for this quite remarkable collection of papers, which report many fascinating discoveries and insights.