179 research outputs found
Elliptic logarithms, diophantine approximation and the Birch and Swinnerton-Dyer conjecture
Most, if not all, unconditional results towards the abc-conjecture rely
ultimately on classical Baker's method. In this article, we turn our attention
to its elliptic analogue. Using the elliptic Baker's method, we have recently
obtained a new upper bound for the height of the S-integral points on an
elliptic curve. This bound depends on some parameters related to the
Mordell-Weil group of the curve. We deduce here a bound relying on the
conjecture of Birch and Swinnerton-Dyer, involving classical, more manageable
quantities. We then study which abc-type inequality over number fields could be
derived from this elliptic approach.Comment: 20 pages. Some changes, the most important being on Conjecture 3.2,
three references added ([Mas75], [MB90] and [Yu94]) and one reference updated
[BS12]. Accepted in Bull. Brazil. Mat. So
Quantitative Chevalley-Weil theorem for curves
The classical Chevalley-Weil theorem asserts that for an \'etale covering of
projective varieties over a number field K, the discriminant of the field of
definition of the fiber over a K-rational point is uniformly bounded. We obtain
a fully explicit version of this theorem in dimension 1.Comment: version 4: minor inaccuracies in Lemma 3.4 and Proposition 5.2
correcte
The effect of substrate on high-temperature annealing of GaN epilayers: Si versus sapphire
We have studied the effects of rapid thermal annealing at 1300¿°C on GaN epilayers grown on AlN buffered Si(111) and on sapphire substrates. After annealing, the epilayers grown on Si display visible alterations with craterlike morphology scattered over the surface. The annealed GaN/Si layers were characterized by a range of experimental techniques: scanning electron microscopy, optical confocal imaging, energy dispersive x-ray microanalysis, Raman scattering, and cathodoluminescence. A substantial Si migration to the GaN epilayer was observed in the crater regions, where decomposition of GaN and formation of Si3N4 crystallites as well as metallic Ga droplets and Si nanocrystals have occurred. The average diameter of the Si nanocrystals was estimated from Raman scattering to be around 3¿nm. Such annealing effects, which are not observed in GaN grown on sapphire, are a significant issue for applications of GaN grown on Si(111) substrates when subsequent high-temperature processing is required
Co(II) and Cu(II) fluorescent complexes with acridine based ligands
The condensation reaction of salicylaldehyde or 2‐hydroxynaphthaldehyde with a diamino organic group (Acridine Yellow or diaminoacridine) resulted in the Schiff‐base ligands ACRI‐1, ACRI‐2 and ACRI‐3, with the last two hitherto unknown. Fluorescent ACRI‐1, ACRI‐2 and ACRI‐3 were designed to provide iminophenolic binding pockets for two transition metals and ferromagnetic exchange between the metals. Following our report on the complex [Co2(ACRI‐1)2] (1Co), we report herein the reactions of ACRI‐1, ACRI‐2 and ACRI‐3 with CoII and CuII salts, which afforded the new fluorescent complexes [Cu2(ACRI‐1)2] (1Cu), [Co2(ACRI‐2)2] (2Co), [Cu2(ACRI‐2)2] (2Cu), [Co2(ACRI‐3)2(H2O)4] (3Co) and [Cu2(ACRI‐3)2] (3Cu
II Jornadas de la Sociedad Española para la Conservación y Estudio de Los Mamíferos (SECEM) Soria 7-9 diciembre 1995
Seguimiento de una reintroducción de corzo (Capreolus capreolus) en ambiente mediterráneo. Dispersión y área de campeoModelos de distribución de los insectívoros ern la Península IbéricaDieta anual del zorro, Vulpes vulpes, en dos hábitats del Parque Nacional de DoñanaDesarrollo juvenil del cráneo en las poblaciones ibéricas de gato montés, Felis silvestris Schreber, 1777Presencia y expansión del visón americano (Mustela vison) en las provincias de Teruel y Castellón (Este de España).Preferencias de hábitat invernal de la musaraña común (Crocidura russula) en un encinar fragmentado de la submeseta norteUso de cámaras automáticas para la recogida de información faunística.Dieta del lobo en dos zonas de Asturias (España) que difieren en carga ganadera.Consumo de frutos y dispersión de semillas de serbal (Sorbus aucuparia L.) por zorros y martas en la cordillera Cantábrica occidentalEvaluación de espermatozoides obtenidos postmorten en el ciervo.Frecuencia de aparición de diferentes restos de conejo en excrementos de lince y zorroAtlas preliminar de los mamíferos de Soria (España)Censo y distribución de la marmota alpina (Marmota marmota) en Navarra.Trampeo fotográfico del género Martes en el Parque Nacional de Aigüestortes i Estany de Sant Maurici (Lleida)Peer reviewe
Corporate ethical identity as a determinant of firm performance : a test of the mediating role of stakeholder satisfaction
In this article, we empirically assess the impact of corporate ethical identity (CEI) on a firm’s financial performance. Drawing on formulations of normative and instrumental stakeholder theory, we argue that firms with a strong ethical identity achieve a greater degree of stakeholder satisfaction (SS), which, in turn, positively influences a firm’s financial performance. We analyze two dimensions of the CEI of firms: corporate revealed ethics and corporate applied ethics. Our results indicate that revealed ethics has informational worth and enhances shareholder value, whereas applied ethics has a positive impact through the improvement of SS. However, revealed ethics by itself (i.e. decoupled from ethical initiatives) is not sufficient to boost economic performance.Publicad
Triggering the internationalization of Malaysian quantity surveying firms
Although there is an increasing trend of services being traded across borders, quantity surveying (QS) firms in the construction sector remain under-researched. The triggers for the increasing globalization of QS firms are not clear, nor how these triggers are perceived by managers at different levels. A questionnaire was administered in over 84 QS consultancy firms, and the results were analyzed using the repertory grid technique, allowing a comparison between the general respondents and a focus group of senior managers. The findings show that senior managers with significant experience realize the importance of a strong internal capability of the QS firm and the capability to develop innovative offerings, coupled with an awareness of the target market and the ability to secure revenue through key contracts. Firm- and location-specific factors were more important than other competitive advantages or foreign markets’ characteristics when deciding to globalize
Corporate reputation in the spanish context: An interaction between reporting to stakeholders and industry.
ABSTRACT: The authors describe the intensity and orientation of the corporate social responsibility (CSR) reporting in four Spanish industries and explore the relationship that exists between both concepts and an independent measurement of reputation for CSR (CSRR). The results demonstrate that the CSR reporting is especially relevant and useful in the finance industry. Finance companies report significantly more CSR information than most industries in Spain, and this reporting is more closely linked to their CSRR than the CSR reporting of basic, consumer goods and services industries.
Borra
International lower limb collaborative (INTELLECT) study: a multicentre, international retrospective audit of lower extremity open fractures
Trauma remains a major cause of mortality and disability across the world1, with a higher burden in developing nations2. Open lower extremity injuries are devastating events from a physical3, mental health4, and socioeconomic5 standpoint. The potential sequelae, including risk of chronic infection and amputation, can lead to delayed recovery and major disability6. This international study aimed to describe global disparities, timely intervention, guideline-directed care, and economic aspects of open lower limb injuries
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