170 resultados para Lie algebras.
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Various sources indicate that threats to modern cities lie in the availability of essential streams, among which energy. Most cities are strongly reliant on fossil fuels; not one case of a fully self-sufficient city is known. Engineering resilience is the rate at which a system returns to a single steady or cyclic state following a perturbation. Certain resilience, for the duration of a crisis, would improve the urban capability to survive such a period without drastic measures.
The capability of cities to prepare for and respond to energy crises in the near future is supported by greater or temporary self-sufficiency. The objective of the underlying research is a model for a city – including its surrounding rural area – that can sustain energy crises. Therefore, accurate monitoring of the current urban metabolism is needed for the use of energy. This can be used to pinpoint problem areas. Furthermore, a sustainable energy system is needed, in which the cycle is better closed. This will require a three-stepped approach of energy savings, energy exchange and sustainable energy generation. Essential is the capacity to store energy surpluses for periods of shortage (crises).
The paper discusses the need for resilient cities and the approach to make cities resilient to energy crises.
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A general approach to information correction and fusion for belief functions is proposed, where not only may the information items be irrelevant, but sources may lie as well. We introduce a new correction scheme, which takes into account uncertain metaknowledge on the source’s relevance and truthfulness and that generalizes Shafer’s discounting operation. We then show how to reinterpret all connectives of Boolean logic in terms of source behavior assumptions with respect to relevance and truthfulness. We are led to generalize the unnormalized Dempster’s rule to all Boolean connectives, while taking into account the uncertainties pertaining to assumptions concerning the behavior of sources. Eventually, we further extend this approach to an even more general setting, where source behavior assumptions do not have to be restricted to relevance and truthfulness.We also establish the commutativity property between correction and fusion processes, when the behaviors of the sources are independent.
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The helminth parasite Fasciola hepatica secretes cysteine proteases to facilitate tissue invasion, migration, and development within the mammalian host. The major proteases cathepsin L1 (FheCL1) and cathepsin L2 (FheCL2) were recombinantly produced and biochemically characterized. By using site-directed mutagenesis, we show that residues at position 67 and 205, which lie within the S2 pocket of the active site, are critical in determining the substrate and inhibitor specificity. FheCL1 exhibits a broader specificity and a higher substrate turnover rate compared with FheCL2. However, FheCL2 can efficiently cleave substrates with a Pro in the P2 position and degrade collagen within the triple helices at physiological pH, an activity that among cysteine proteases has only been reported for human cathepsin K. The 1.4-A three-dimensional structure of the FheCL1 was determined by x-ray crystallography, and the three-dimensional structure of FheCL2 was constructed via homology-based modeling. Analysis and comparison of these structures and our biochemical data with those of human cathepsins L and K provided an interpretation of the substrate-recognition mechanisms of these major parasite proteases. Furthermore, our studies suggest that a configuration involving residue 67 and the "gatekeeper" residues 157 and 158 situated at the entrance of the active site pocket create a topology that endows FheCL2 with its unusual collagenolytic activity. The emergence of a specialized collagenolytic function in Fasciola likely contributes to the success of this tissue-invasive parasite.
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Rhizosphere microorganisms play an important role in soil carbon flow, through turnover of root exudates, but there is little information on which organisms are actively involved or on the influence of environmental conditions on active communities. In this study, a (CO2)-C-13 pulse labelling field experiment was performed in an upland grassland soil, followed by RNA-stable isotope probing (SIP) analysis, to determine the effect of liming on the structure of the rhizosphere microbial community metabolizing root exudates. The lower limit of detection for SIP was determined in soil samples inoculated with a range of concentrations of C-13-labelled Pseudomonas fluorescens and was found to lie between 10(5) and 10(6) cells per gram of soil. The technique was capable of detecting microbial communities actively assimilating root exudates derived from recent photo-assimilate in the field. Denaturing gradient gel electrophoresis (DGGE) profiles of bacteria, archaea and fungi derived from fractions obtained from caesium trifluoroacetate (CsTFA) density gradient ultracentrifugation indicated that active communities in limed soils were more complex than those in unlimed soils and were more active in utilization of recently exuded C-13 compounds. In limed soils, the majority of the community detected by standard RNA-DGGE analysis appeared to be utilizing root exudates. In unlimed soils, DGGE profiles from C-12 and C-13 RNA fractions differed, suggesting that a proportion of the active community was utilizing other sources of organic carbon. These differences may reflect differences in the amount of root exudation under the different conditions.
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This paper is a contribution to Mathematical fuzzy logic, in particular to the algebraic study of t-norm based fuzzy logics. In the general framework of propositional core and ?-core fuzzy logics we consider three properties of completeness with respect to any semantics of linearly ordered algebras. Useful algebraic characterizations of these completeness properties are obtained and their relations are studied. Moreover, we concentrate on five kinds of distinguished semantics for these logics-namely the class of algebras defined over the real unit interval, the rational unit interval, the hyperreals (all ultrapowers of the real unit interval), the strict hyperreals (only ultrapowers giving a proper extension of the real unit interval) and finite chains, respectively-and we survey the known completeness methods and results for prominent logics. We also obtain new interesting relations between the real, rational and (strict) hyperreal semantics, and good characterizations for the completeness with respect to the semantics of finite chains. Finally, all completeness properties and distinguished semantics are also considered for the first-order versions of the logics where a number of new results are proved. © 2009 Elsevier B.V. All rights reserved.
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In many coastal areas of North America and Scandinavia, post-glacial clay sediments have emerged above sea level due to iso-static uplift. These clays are often destabilised by fresh water leaching and transformed to so-called quick clays as at the investigated area at Smørgrav, Norway. Slight mechanical disturbances of these materials may trigger landslides. Since the leaching increases the electrical resistivity of quick clay as compared to normal marine clay, the application of electromagnetic (EM) methods is of particular interest in the study of quick clay structures.
For the first time, single and joint inversions of direct-current resistivity (DCR), radiomagnetotelluric (RMT) and controlled-source audiomagnetotelluric (CSAMT) data were applied to delineate a zone of quick clay. The resulting 2-D models of electrical resistivity correlate excellently with previously published data from a ground conductivity metre and resistivity logs from two resistivity cone penetration tests (RCPT) into marine clay and quick clay. The RCPT log into the central part of the quick clay identifies the electrical resistivity of the quick clay structure to lie between 10 and 80 O m. In combination with the 2-D inversion models, it becomes possible to delineate the vertical and horizontal extent of the quick clay zone. As compared to the inversions of single data sets, the joint inversion model exhibits sharper resistivity contrasts and its resistivity values are more characteristic of the expected geology. In our preferred joint inversion model, there is a clear demarcation between dry soil, marine clay, quick clay and bedrock, which consists of alum shale and limestone.
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The system TlCo2Se2-xSx has been thoroughly investigated by neutron powder diffraction and SQUID magnetometry. TlCo2Se2-xSx is a layered tetragonal structure containing atomic cobalt layers separated by a distance of 6.4 angstrom in the sulphide and 6.8 angstrom in the selenide. The solid solubility of isovalent selenium and sulphur atoms in the structure makes it possible to continuously vary the interlayer distance and thereby tune the magnetic coupling between the Co-layers. At low temperatures, the Co-atoms are ferromagnetically ordered within the layers and magnetic moments lie in the ab-plane. However, these Co-moments form a helical magnetic structure that prevails for 0 <= x <= 1.5 with a gradual decrease of the angle between adjacent Co-layers from 122 degrees to 39 degrees. For x >= 1.75, a collinear ferromagnetic structure is stable. The relationship between the coupling angle and the Co-interlayer separation shows an almost linear behaviour. The helical phase contains no net spontaneous magnetic moment up to TlCo2SeS, where a small net magnetic moment appears that increases until the ferromagnetic structure is found for 1.75 <= x <= 2.0. (C) 2005 Elsevier B.V. All rights reserved.
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This article critically assesses the criminal law on consensual harm through an examination of the legality of fighting sports. The article begins by considering fighting sports such as bare-fisted prize fighting (dominant in the nineteenth century). It then, in historical chronology, examines the legality of professional boxing with gloves (dominant in the twentieth century). Doctrinally, the article reviews why and how, in a position adopted by the leading common law jurisdictions, fighting sports benefit from an application of the “well-established” category-based exceptions to the usual bodily harm threshold of consent in the criminal law. Centrally, fighting sports and doctrinal law on offenses against the person are juxtaposed against the theoretical boundaries of consent in the criminal law to examine whether and where the limit of the “right to be hurt” might lie. In sum, this article uses fighting sports as a case study to assess whether the criminal law generally can or should accommodate the notion of a fair fight, sporting or otherwise, predicated on the consent of the participants to the point that the individuals involved might be said, pithily, to have extended an open invite to harm.
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Cette communication a pour objectif de présenter et d’analyser les résultats d’une enquête portant sur l’accord sujet-verbe en français contemporain. Dans le domaine de l’accord sujet-verbe, bien que dans la plupart des cas le locuteur n’ait pas le choix de l’accord – c’est–à-dire qu’il n’y a qu’un accord possible – il existe néanmoins des contextes dans lesquels on peut trouver une variation entre l’accord singulier et le pluriel (cf. Corbett 2006 ; Grevisse 1993 ; Riegel et al 1994). Cette variation est souvent liée à une discordance entre le nombre syntaxique et le nombre sémantique. C’est le cas de certaines expressions de quantité, comme dans les exemples suivants : Singulier : « On a affaire à une minorité qui fait la loi à l’université » (Ouest France, 23-24 mai 2009, p.13) Pluriel : « Un petit millier de producteurs allemands, français et belges se sont déplacés, hier, à Bruxelles […] » (Ouest France, 26 mai 2009, p.3) Cette variation nous offre plusieurs pistes de recherche : dans une perspective linguistique, elle peut nous aider à mieux comprendre comment interagissent les différents facteurs linguistiques qui ont une influence sur l’accord, et dans une perspective sociolinguistique, elle représente un nouveau domaine à explorer pour l’étude sociolinguistique de la variation grammaticale en français, ce qui reste jusqu’à présent relativement peu étudiée. Nous traitons dans cette communication de la perspective sociolinguistique, c'est-à-dire les facteurs externes tels que l’âge, le sexe, et le niveau d’éducation du locuteur qui jouent un rôle dans l’accord sujet-verbe avec les expressions de quantité. Nous considérons en particulier la variation sexolectale : dans un premier temps, nous examinons les résultats de quelques études précédentes de la variation morphosyntaxique en français contemporain par rapport à l’influence du sexe du locuteur. Nous en concluons que les Principes élaborés par Labov (1990) pour décrire la variation sexolectale en anglais semblent être moins valables pour le cas du français de la France ; ou bien, qu’ils ne s’appliquent pas de façon simpliste. Dans un deuxième temps, nous présentons les résultats de nôtre étude, et nous voyons que pour nôtre projet aussi, les résultats pour la variation sexolectale ne s’expliquent pas facilement dans le cadre des Principes de Labov (1990).
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Dans cet article, nous évaluons le rôle du cotexte (les facteurs internes ou linguistiques) et du contexte (les facteurs externes ou sociaux, et la situation de l’interaction) dans l’accord sujet-verbe induit par les expressions de quantité en français contemporain. Dans l’emploi de ces expressions, par exemple la majorité, le reste etc., il existe une variation entre l’accord singulier et le pluriel, qui est liée à une discordance entre le nombre syntaxique et le nombre sémantique de l’expression. Dans un premier temps, nous présentons la méthodologie d’une première enquête dont le but était d’identifier les principaux facteurs internes et externes qui ont une influence sur les accords de ce type. Dans un deuxième temps, nous présentons les résultats pour les facteurs sociaux avant d’en tirer quelques conclusions pour l’étude principale.
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We describe the C*-algebras of " ax+b" -like groups in terms of algebras of operator fields defined over their dual spaces.
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Biomarkers are conventionally defined as "biological molecules that represent health and disease states." They typically are measured in readily available body fluids (blood or urine), lie outside the causal pathway, are able to detect subclinical disease, and are used to monitor clinical and subclinical disease burden and response to treatments. Biomarkers can be "direct" endpoints of the disease itself, or "indirect" or surrogate endpoints. New technologies (such as metabolomics, proteomics, genomics) bring a wealth of opportunity to develop new biomarkers. Other new technologies enable the development of nonmolecular, functional, or biophysical tissue-based biomarkers. Diabetes mellitus is a complex disease affecting almost every tissue and organ system, with metabolic ramifications extending far beyond impaired glucose metabolism. Biomarkers may reflect the presence and severity of hyperglycemia (ie, diabetes itself) or the presence and severity of the vascular complications of diabetes. Illustrative examples are considered in this brief review. In blood, hemoglobin A1c (HbA1c) may be considered as a biomarker for the presence and severity of hyperglycemia, implying diabetes or prediabetes, or, over time, as a "biomarker for a risk factor," ie, hyperglycemia as a risk factor for diabetic retinopathy, nephropathy, and other vascular complications of diabetes. In tissues, glycation and oxidative stress resulting from hyperglycemia and dyslipidemia lead to widespread modification of biomolecules by advanced glycation end products (AGEs). Some of these altered species may serve as biomarkers, whereas others may lie in the causal pathway for vascular damage. New noninvasive technologies can detect tissue damage mediated by AGE formation: these include indirect measures such as pulse wave analysis (a marker of vascular dysfunction) and more direct markers such as skin autofluorescence (a marker of long-term accumulation of AGEs). In the future, we can be optimistic that new blood and tissue-based biomarkers will enable the detection, prevention, and treatment of diabetes and its complications long before overt disease develops.
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In the throes of her mimetic exposure of the lie of phallocratic discursive unity in 'Speculum of the Other Woman', Irigaray paused on the impossibility of woman’s voice and remarked that ‘it [was] still better to speak only in riddles, allusions, hints, parables.’ Even if asked to clarify a few points. Even if people plead that they just don’t understand. After all, she said, ‘they never have understood.’ (Irigaray 1985, 143).
That the law has never understood a uniquely feminine narrative is hardly controversial, but that this erasure continues to have real and substantive consequences for justice is a reality that feminists have been compelled to remain vigilant in exposing. How does the authority of the word compound law’s exclusionary matrix? How does law remain impervious to woman’s voice and how might it hear woman’s voice? Is there capacity for a dialogic engagement between woman, parler femme, and law?
This paper will explore these questions with particular reference to the experience of women testifying to trauma during the rape trial. It will argue that a logically linked historical genealogy can be traced through which law has come to posit itself as an originary discourse by which thinking is very much conflated with being, or in other terms, law is conflated with justice. This has consequences both for women’s capacity to speak or represent the harm of rape to law, but also for law’s ability to ‘hear’ woman’s voice and objectively adjudicate in cases of rape. It will suggest that justice requires law acknowledge the presence of two distinct and different subjects and that this must be done not only at the symbolic level but also at the level of the parole, syntax and discourse.