117 resultados para 4098
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Let m and n be integers greater than 1. Given lattices A and B of dimensions m and n, respectively, a technique for constructing a lattice from them of dimension m+n-1 is introduced. Furthermore, if A and B possess bases satisfying certain conditions, then a second technique yields a lattice of dimension m+n-2. The relevant parameters of the new lattices are given in terms of the respective parameters of A,B, and a lattice C isometric to a sublattice of A and B. Denser sphere packings than previously known ones in dimensions 52, 68, 84, 248, 520, and 4098 are obtained. © 2012 Elsevier Inc. All rights reserved.
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Incluye Bibliografía
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This paper will contend that the post-2015 development agenda presents a major opportunity for Caribbean countries to reverse decades of lagging economic performance and make the transition to balanced, holistic, and people-centred growth and development. The MDGs, while valuable in promoting gains in poverty reduction, health, education, nutrition, and maternal well-being were not tailored to the growth and development needs of the region. This can now be changed by a post-2015 development agenda which goes beyond improving the welfare of citizens by meeting basic needs and enhancing access to primary services. The necessary scaling-up of the MDG framework will require that the sustainable development goals, which will anchor the post- 2015 development agenda, are capable of promoting structural change, competitiveness and output gains while advancing social development and meeting environmental concerns. They must also address the unfinished business of the millennium development goals, primarily in the area of human development.
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Pós-graduação em Ciência Florestal - FCA
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A violência é um problema de saúde pública e sua notificação é fundamental para a vigilância epidemiológica e para a definição de políticas públicas de prevenção e promoção de saúde. O estudo objetivou caracterizar a ocorrência de violência doméstica, sexual e de outras, a partir das informações do banco de dados do Sistema Informação de Agravos de Notificação (SINAN), das fichas de notificação de violência da cidade de Belém (PA), no período de janeiro de 2009 a dezembro de 2011. Foram sistematizadas 3.267 notificações, representando um aumento de 240% de 2009 a 2011. Em relação ao sexo das vítimas, observou-se que, em média, 83,2% dos casos atingiram as mulheres, proporção esta semelhante nos três anos analisados. A violência sexual foi a mais presente com 41,8%; seguida da violência psicológica com 26,3% e da violência física com 24,0%. Os resultados demonstram a importância do conhecimento do perfil das violências para intervenção e elaboração de políticas públicas intersetoriais que promovam a saúde e a qualidade de vida nesta região do Brasil.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The overall aim of the present thesis was to develop and characterise an age assessment method based on incremental lines in dental cementum using contemporary bovine teeth and teeth from archaeological faunal assemblages. The investigations also included two other age assessment methods: tooth wear pattern and macroscopic dental measurements. The first permanent mandibular molar and lower jaws from 70 contemporary cattle of known age and 170 archaeological molar sets from ten different Swedish archaeological sites were used. The following conclusions were drawn: • The number of incremental lines in the dental cementum varied between different parts of the tooth root as well as within one and the same individual. The results from contemporary cattle of known age showed a strong relationship between age and incremental lines in the cementum of the distal part of the mesial root (R2=65.5%) and the known ages of the animals. • With the “best” model variation in age could be explained to 65.5% (R2) by the number of incremental lines. Thus, the remaining age variation (approximately 35%) could not be explained by these lines. Other factors than must thus be responsible. However, with the exception of calves born the present material did not reveal any such significant relationship. • The results from cattle of known age indicate that the method of assessing age on the basis of cemental incremental lines is more reliable than other methods such as tooth wear or tooth measurements. However, by combining counting incremental lines and one variable assessing tooth dimension (tooth height) a slightly stronger relationship could be obtained (R2=74.5%). The results from age assessment of the medieval and post-Reformation cattle emphasize the importance of supplementing any age estimation of archaeological assemblages based on dental indicators with characteristics for the particular assessment model. Furthermore, conclusions based on age assessment with such models can not be drawn with any more detailed time scale than about 2 years leaving at best only 25% (R2) of factors influencing the dental indicator(s) utilized in the model unexplained. The accuracy of the age assessment required by the particular historical context in which the archaeological remains are found should thus decide what level of accuracy should be chosen.
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Le vesti e le insegne degli imperatori nonché degli alti dignitari, sono ornate e “appesantite” da pietre preziose, lì disposte non a caso. Esse spesso divengono emblemi dei personaggi che le portano e offrono loro virtù e qualità che spesso si ricollegano anche a caratteristiche di alto valore ideologico. Già dai tempi pre-biblici le pietre sono considerate creature vive, messe in corrispondenza con gli astri, secondo la dottrina della simpathia. Questa concezione perdura anche nel Medioevo: infatti, nei vari lapidari vi sono pietre capaci di generare, e pietre “incinte”; esistono pietre dalle virtù talismaniche e taumaturgiche; altre guariscono, allontanano i mali, ottengono il favore dei potenti, consentono di portare a felice compimento tutto quel che si intraprende; rendono eloquenti, simpatici, graditi. Tornando all’ambito imperiale, l’imperatore per governare deve manifestare qualità che vengono condivise anche da Dio, quali la filantrophia, l’eunomia; rispettare la taxis; essere capace di autocontrollo; mostrare pietà; essere filocristos, vittorioso, misericordioso; essere temperante e giusto. Alcune di queste qualità gli vengono offerte anche dall’uso delle pietre preziose; così ad esempio il diamante dà forza e coraggio: preserva l’integrità del carattere e la buona fede; il rubino allude alla fiamma della carità; lo zaffiro è simbolo della ricchezza e dei cieli, custode dell’innocenza e della verità; lo smeraldo è anche esso simbolo della fede e allude simbolicamente alla capacità di intuire e trasmettere il messaggio divino propria del personaggio che ne è adornato. Le fonti prese in esame anche se vengono separate da un’arco di tempo grande e non rispecchiano un limite cronologico fisso, neccessario per ogni ricerca, tuttavia permettono di delineare il percorso evolutivo delle virtù delle gemme attraverso i secoli; e quindi di avere un’ idea molto più chiara sulla concezione delle pietre stesse, e su come, col passare degli anni, queste virtù si evolvono o svaniscono.
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Since the development of quantum mechanics it has been natural to analyze the connection between classical and quantum mechanical descriptions of physical systems. In particular one should expect that in some sense when quantum mechanical effects becomes negligible the system will behave like it is dictated by classical mechanics. One famous relation between classical and quantum theory is due to Ehrenfest. This result was later developed and put on firm mathematical foundations by Hepp. He proved that matrix elements of bounded functions of quantum observables between suitable coherents states (that depend on Planck's constant h) converge to classical values evolving according to the expected classical equations when h goes to zero. His results were later generalized by Ginibre and Velo to bosonic systems with infinite degrees of freedom and scattering theory. In this thesis we study the classical limit of Nelson model, that describes non relativistic particles, whose evolution is dictated by Schrödinger equation, interacting with a scalar relativistic field, whose evolution is dictated by Klein-Gordon equation, by means of a Yukawa-type potential. The classical limit is a mean field and weak coupling limit. We proved that the transition amplitude of a creation or annihilation operator, between suitable coherent states, converges in the classical limit to the solution of the system of differential equations that describes the classical evolution of the theory. The quantum evolution operator converges to the evolution operator of fluctuations around the classical solution. Transition amplitudes of normal ordered products of creation and annihilation operators between coherent states converge to suitable products of the classical solutions. Transition amplitudes of normal ordered products of creation and annihilation operators between fixed particle states converge to an average of products of classical solutions, corresponding to different initial conditions.
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Der erste Teil der hier vorgestellten Arbeit verfolgt die Synthese potentieller Modellverbindungen oligonuklearer Metalloproteine auf Basis von Salen-Liganden. Dazu wurden zwei Ligandensysteme mit unterschiedlich raumerfüllenden Alkyl-Substituenten modifiziert und auf ihre koordinativen Eigenschaften hin untersucht. Für das Ligandensystem auf Basis des Bis-(salicylidenamino)-propan-2-ols konnten fünf Derivate (H3L1, H3L2A,H3L2B, H3L3, H3L4), für das zweite verwendete Ligandensystem auf Basis des 1H-3,5-Bis-(salicylidenaminomethyl)-pyrazols konnten zwei weitere Derivate (H3L5A, H3L5B) dargestellt und zu Koordinationsverbindungen umgesetzt werden.rnFür den hier verwendeten Bis-(salicylidenamino)-propan-2-ol Liganden H3L1, welcher die geringsten sterischen Anforderungen stellt, konnten mono-, tri- und tetranukleare Koordinationsverbindungen synthetisiert werden. Dabei gelingt es dem Liganden, sich sowohl in planarer als auch in unterschiedlich stark gewinkelter Konformation um ein oder mehrere Metallzentren anzuordnen, wobei der Ligand ein N2O2- seines N2O3-Donorsets zur Koordination nutzt. Die Verbindung {[Ni7(HL1)2(L1)2(OBz)4(OMe)(H2O)]}n zeigt, dass eine Verkettung der so gestalteten dreikernigen Einheiten über das freie Propanol-Sauerstoffatomdes Ligandenrückgrats möglich ist. Mit zunehmendem sterischen Anspruch der angefügten Alkylsubstituenten nimmt die geometrische Flexibilität und somit das Potential des Liganden zur Ausbildung höhernuklearer Strukturen ab. So ist für Liganden mit mittlerem sterischen Anspruch neben mononuklearen Komplexen noch die Gestaltung dinuklearer Systeme möglich. Erhöht man den sterischen Anspruch des Liganden weiter, findet nur noch eine Reaktion zu mononuklearen Verbindungen statt.rnMit den Pyrazol-basierten Ligandensystemen H3L5A und H3L5B konnten dinukleare Kupfer- und Nickelverbindungen synthetisiert werden.rnDer zweite Teil dieser Arbeit befasst sich mit der Gestaltung von Spin-Crossover Systemen (SCO). Dazu soll ein Spinübergang innerhalb des gestalteten schaltbaren Systems an die Anwesenheit eines Signalstoffs gekoppelt werden, so dass diese SCO-Verbindung als Sensor für den Signalstoff eingesetzt werden kann. Dazu wurden zwei unterschiedliche Ansätze entwickelt und untersucht.rnDie erste Methode beruht auf der Kombination eines zum Spin-Crossover befähigten Metallzentrums, eines Capping-Liganden, eines zur Signalstofferkennung funktionalisierten Co-Liganden sowie eines entsprechenden Signalstoffs. Als Capping-Liganden wurden tetra- und pentadentateLigandensysteme eingesetzt und mit unterschiedlich Picolyl-substituierten Monoaza-[12]-krone-4-Derivaten umgesetzt, wobei die Monoazakrone zur Komplexierung des Signalstoffs,hier in Form eines Alkalimetallions, zur Verfügung steht. Nach dieser ersten Methode konnten im Zeitraum dieser Arbeit noch keine zufriedenstellenden Ergebnisse erzielt werden.rnEine vielversprechende zweite Möglichkeit beruht auf der Verwendung eines mehrzähnigen, etablierten Spin-Crossover Liganden,welcher in seiner Peripherie mit einer Bindungstasche zur Aufnahme des Signalstoffmodifiziert wird.Mit Hilfe des so gestalteten Liganden 4'-(4'''-Benzo-[15]-krone-5)-methyloxy-2,2':6',2''-terpyridin ([b15c5]-tpy) gelang die Umsetzung zu entsprechenden Eisen(II)- und Kobalt(II)komplexen der Zusammensetzung [M([b15c5]-tpy)2]2+. Alle synthetisierten Eisen(II)-Komplexe liegen aufgrund der hohen Ligandenfeldstärke des Terpyridins über einen Temperaturbereich von 300 – 400 K in ihrer diamagnetischen Low Spin Form vor. Die entsprechenden Kobalt(II)-Komplexe zeigen über einen Temperaturbereich von 2 – 350 K ein kontinuierliches, aber unvollständiges Spin-Crossover Verhalten.rnDer Einfluss von Signalstoffen auf das Spin-Crossover Verhalten der Kobalt(II)-Systeme wurde in einem ersten Versuch unter der Verwendung von Natriumionen als Signalstoff untersucht. Dabei stellte sich heraus, dass Natriumionen für dieses System zwar nicht als Auslöser eines SCO verwendet werden können, sie aber dennoch eine starke Auswirkung auf den Verlauf des Spin-Crossovers haben.