We study various binomial and monomial ideals arising in the theory of divisors, orientations, and matroids on graphs. We use ideas from potential theory on graphs and from the theory of Delaunay decompositions for lattices to describe their minimal polyhedral cellular free resolutions. We show that the resolutions of all these ideals are closely related and that their Z-graded Betti tables coincide. As corollaries, we give conceptual proofs of conjectures and questions posed by Postnikov and Shapiro, by Manjunath and Sturmfels, and by Perkinson, Perlman, and Wilmes. Various other results related to the theory of chip-firing games on graphs also follow from our general techniques and results.

During the past several decades, agricultural intensification has been crucial to increase the food supply. Several processes related to intensification are very detrimental to the environment, particularly biodiversity. Today, agriculture is facing the challenge of satisfying its demand for food while improving its environmental sustainability. Knowledge of the shape of the relationship between biodiversity and intensity is necessary to determine both where conservation policies will be most effective and how to allocate intensity to reconcile production and biodiversity. Few empirical studies on this relationship exist, and the influence of the spatial arrangement of intensity on biodiversity remains untested. This Ph.D. thesis determined how to target both agricultural intensity and its spatial allocation for meeting production and conservation objectives of farmlands. To answer this research question, we used a country-scaled approach that combined two France-scaled databases that describe agriculture and farmland birds. We characterized a nationwide gradient of agricultural intensity and studied a farmland bird community along this gradient, using several trait-based descriptors (specialization, trophic level, and species main habitat). Agricultural intensity and bird communities were described at the Small Agricultural Region (SAR; mean width = 22.4 km) level. As a first step, we developed a novel method to estimate an intensity indicator that was based on Input Costs/ha, with SAR resolution. This indicator provides a continuous intensity measure that is relevant across different types of agricultural systems. Secondly, we investigated the effects of a gradient of land uses (grassland to arable land) and its heterogeneity on the bird community. We found habitat specialists suffered from habitat loss, while generalists benefited from heterogeneity. Thirdly, we showed that the community responded significantly to intensity, with winner species replacing loser species along the gradient. The shift between losers and winners was sharper at low intensities. Interestingly, spatial aggregation of intensity had a strengthening effect on the bird community. Finally, the relationships linking intensity to the bird community, food production, and economic performance were integrated into a model aimed at optimizing intensity allocation. Optimal allocations reached win-no-lose solutions with the three criteria. They corresponded to targeted intensity modifications: many small changed, favoring homogeneous, extensive clusters, were optimal within an extensification scenario; while a few large changes, favoring heterogeneity, were optimal within an intensification scenario. We provide one of the first studies demonstrating that spatial aggregation of intensity can influence the biodiversity/intensity relationship. Our results also provide an opportunity to improve the effectiveness of conservation policies, at national scales, with spatial targeting: opposite targeting should be performed either to maximize biodiversity benefits or to increase production, while mitigating biodiversity impacts. Our results highlight the importance of mixed allocation strategies between land sparing/sharing extremes. In order to put these opportunities into effect, further research should address the technical solutions that achieve intensity modification at the farm level and design targeted policies that benefit biodiversity and other environmental criteria

How is Stravinky still recognisable even if he “merely” transcribes someone else’s work and orchestrates almost without changing pitch and rhythm? What technical procedures enable him to add a certain haptic and physical feel to the sound? As Wolfgang Rihm once said, Stravinsky formed music – even that of others – with his big hands to suit it to his own image and thereby paving two ways: one historical and the other personal. Both of these lead to Venice. This essay concentrates on the analysis of Stravinsky\'s Two sacred songs from 1968. An accurate profile may be given to the results by comparing them with the orchestration (written for nearly the same instruments) which is realized in Gérard Grisey’s Wolf-Lieder from 1997. Works from the German-Austrian compositional tradition conflict both with Stravinsky’s and Grisey’s arrangements on account of a sensitivity to timbre that dates from an originally French tradition of orchestration. It will be shown that counterpoint can effectively become a neutralizing agent in this clash of cultures.

Pharmacists experience high levels of stress at work, especially from factors intrinsic to their jobs and management roles. In South Africa, the public sector is confronted with situational difficulties such as a shortage of staff and poor working conditions Accordingly, a comparative survey was conducted using a self–constructed questionnaire to obtain individual responses from the pharmacists in the public, as well as the private sector. The focus population was the pharmacists in the public, as well as the private hospitals in the North–West Province. The public sector consists of 30 hospitals and the private sector of 20. By using the convenient sampling method, 100 samples were taken. The questionnaire measured six factors of job satisfaction, namely: job design, salary/remuneration satisfaction, performance management, working arrangements, organisational climate, and professional development. The questionnaire was distributed to 100 pharmacists in total, and a response rate of 66% was obtained. The only medium practical significance shown in the results was between the averages of the private sector (2.89) in contrast with the public sector (3.38). This indicates that the public sector demonstrates less satisfaction with their performance management than the private sector. The data also indicated that the public sector pharmacists are less satisfied with job design, performance of management, professional development, and their working arrangements. The private sector showed only a small difference in the means, when compared to the public sector. It is clear that both sectors illustrate a moderate level of job satisfaction. Recommendations, therefore, included the revisiting of the job design by increasing job rotation and task identity. The need for self–actualization has to be acknowledged and the opportunity for promotion needs to be provided. The link between the actual activity and the bonus, with regards to performance management, has to be re–established, and there has to be transparency throughout. Decision–making control is extremely important and seeing that 82% of the pharmacists were female, the employer can consider accommodating family responsibilities, compressed working weeks, flexible working hours, job sharing, and part–time work. Professional development is also very important within any company and it is vital that the employer deposits time, money and skill into the staff. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2011.

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Pharmacists experience high levels of stress at work, especially from factors intrinsic to their jobs and management roles. In South Africa, the public sector is confronted with situational difficulties such as a shortage of staff and poor working conditions Accordingly, a comparative survey was conducted using a self–constructed questionnaire to obtain individual responses from the pharmacists in the public, as well as the private sector. The focus population was the pharmacists in the public, as well as the private hospitals in the North–West Province. The public sector consists of 30 hospitals and the private sector of 20. By using the convenient sampling method, 100 samples were taken. The questionnaire measured six factors of job satisfaction, namely: job design, salary/remuneration satisfaction, performance management, working arrangements, organisational climate, and professional development. The questionnaire was distributed to 100 pharmacists in total, and a response rate of 66% was obtained. The only medium practical significance shown in the results was between the averages of the private sector (2.89) in contrast with the public sector (3.38). This indicates that the public sector demonstrates less satisfaction with their performance management than the private sector. The data also indicated that the public sector pharmacists are less satisfied with job design, performance of management, professional development, and their working arrangements. The private sector showed only a small difference in the means, when compared to the public sector. It is clear that both sectors illustrate a moderate level of job satisfaction. Recommendations, therefore, included the revisiting of the job design by increasing job rotation and task identity. The need for self–actualization has to be acknowledged and the opportunity for promotion needs to be provided. The link between the actual activity and the bonus, with regards to performance management, has to be re–established, and there has to be transparency throughout. Decision–making control is extremely important and seeing that 82% of the pharmacists were female, the employer can consider accommodating family responsibilities, compressed working weeks, flexible working hours, job sharing, and part–time work. Professional development is also very important within any company and it is vital that the employer deposits time, money and skill into the staff. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2011.

Gegenstand der vorliegenden Arbeit ist die Entwicklung einer optimalen Tragstruktur für Netzwerkbogenbrücken. Dabei wird die systematische Nutzung der Optimierungspotenziale dieses Brückentragwerkes an ausgewählten Tragwerkselementen erarbeitet. Es werden Lösungsvorschläge für die System- und Detailausbildung sowie Berechnungs- und Entwurfsgrundlagen entwickelt. Die Schwerpunkte der Arbeit bilden die Entwicklung von ermüdungssicheren Hängeranschlusskonstruktionen, statisch effizienten Hängernetzen sowie Bögen, die sich durch eine hohe Tragfähigkeit bei gleichzeitig geringem Materialverbrauch auszeichnen. Um eine ausreichende Ermüdungssicherheit der in dieser Hinsicht maßgebenden Hängeranschlusskonstruktionen zu gewährleisten, ist es notwendig, die risserzeugenden Spannungsspitzen zu minimieren und möglichst einen homogenen Spannungsverlauf über das gesamte Bauteil zu erzeugen. Mit Hilfe einer parametergestützten Gestaltoptimierung und anschließender Topologieanpassung wird zunächst eine optimale Lösung für die Hängeranschlusskonstruktion entworfen. Anschließend erfolgt die Entwicklung einer Bestimmungsgleichung für die Kerbwirkungszahl dieser Anschlusskonstruktion, welche die Anwendung des Kerbspannungskonzeptes für Hängeranschlüsse ermöglicht. Zur effizienten Nutzung der statischen Vorteile von Netzwerkbogenbrücken ist die Anordnung der Hänger von großer Bedeutung. Um die vorteilhafteste Hängeranordnung zu ermitteln, werden fünf mögliche Hängernetze mit variierenden Hängerneigungsparametern, Hängeranzahlen und Stützweiten hinsichtlich gezielt ausgewählter statischer Kriterien untersucht und bewertet. Daraus resultierend werden Empfehlungen formuliert, die dem Ingenieur die Wahl eines für entsprechende Rahmenbedingungen geeigneten Hängernetzes erleichtern. Auch die konstruktive Ausführung des Bogens sowie des oberen Windverbandes und das damit verbundene Tragverhalten sind beim Entwurf einer effizienten Netzwerkbogenbrücke von großer Bedeutung. Deswegen wird der Einfluss von Form, Geometrie und Steifigkeit des Bogens sowie von Ausführung und Konstruktion anderer Tragwerksteile auf die Bogenstabilität analysiert. Darauf aufbauend erfolgt die Optimierung dieser Konstruktionsparameter, um die Stahlmasse des Bogens ohne maßgebliche Reduzierung der Tragfähigkeit zu minimieren. Zusätzlich werden verschiedene Ersatzimperfektionen bezüglich ihrer Auswirkung auf die rechnerische Bogenstabilität untersucht und die maßgebenden Vorverformungen hinsichtlich ihrer Form und ihrer Größe herausgestellt. In ausgewählten Beispielen werden abschließend die entwickelten Lösungen mit Bauwerken aus der Praxis verglichen, um die Effizienz des optimierten Tragwerkes zu demonstrieren. / This work of research will tackle the development of an optimal structure for network arch bridges. The systematic employment of potentials to optimize these bridge structures will be examined for selected structural members. Suggestions for the construction of the bridge system and of selected details as well as basics for calculation and design will be developed. This paper will focuses mainly on the design of fatigue-proof hanger connections, statically efficient hanger networks as well as arches, which have a high load carrying capacity along with low material consumption. In order to provide sufficient security against fatigue failure for the decisive connections of the hanger bars, stress peaks that cause cracks have to be minimized and homogeneous stress distribution within the whole element has to be ensured. Initially, this paper will delineate an optimal solution for hanger connections by means of parameter-based shape optimization and subsequent topology adaptation. In the following, an analytic formula for the stress concentration factor of this connection will be developed in order to enable the application of the notch stress concept for hanger connections. To apply the static advantages of network arch bridges efficiently, the arrangement of the hangers is essential. In order to determine the most efficient hanger arrangement, five possible hanger arrangements with varying parameters (slope of the hangers, number of the hangers and span of the bridge) will be analyzed and evaluated with respect to systematically selected static criteria. On the basis of these investigations, recommendations for engineers how to choose an optimized hanger arrangement according to different geometrical bridge parameters will be made. Additionally, the constructive design of the arches and the upper wind bracing as well as the associated structural behavior are significant when an efficient network arch bridge is to be designed. For this reason, this paper will analyze the influence of the arch-shape, the arch-geometry and the arch-stiffness as well as the design and construction of other structural members on the stability of the arch. Based on these results, the constructive parameters will be optimized in order to reduce the steel weight of the arch without significantly reducing the load carrying capacity. Furthermore, the influence of different imperfections on the arch stability will be analyzed and the form and size of the decisive initial deflections emphasized. Finally, systematically selected examples will provide a comparison between the developed solutions and existing bridge structures in order to demonstrate the efficiency of the optimized structure.

Resumo: A consorciação de culturas, que consiste no cultivo de duas ou mais culturas em uma mesma área, pelo menos parte do ciclo, visa o melhor aproveitamento dos recursos disponíveis na propriedade e a minimização dos riscos de quebra de produtividade. O cultivo do milho em consórcio com o feijão-caupi, que é relativamente mais tolerante à seca, devido, principalmente, ao ciclo mais curto, pode ser uma opção interessante para o período de safrinha. Contudo, são escassos e inconsistentes os resultados de pesquisas sobre cultivo consorciado de cultivares de milho e feijão-caupi em faixas, especialmente nas regiões Centro- Oeste e Sudeste. Assim, objetivou-se com este trabalho avaliar o monocultivo e o cultivo consorciado em faixas de diferentes cultivares de feijão-caupi com uma variedade e um híbrido simples de milho, em Dourados-MS e Botucatu-SP. O delineamento experimental foi o de blocos casualizados, com parcelas subdivididas e quatro repetições. Para a cultura do feijão-caupi, foram considerados três sistemas de cultivo/cultivares de milho (consórcio com a variedade de milho (BR 473), consórcio com o híbrido de milho (BRS 1030 ou BRS 1010) e cultivo solteiro) nas parcelas e três cultivares de feijão-caupi (BRS Guariba, BRS Novaera e BRS Xiquexique) nas subparcelas. Para a cultura do milho, foram utilizadas duas cultivares de milho (BR 473 e BRS 1030 ou BRS 1010) nas parcelas e quatro sistemas de cultivo/cultivares de feijão-caupi (consórcio com BRS Guariba, consórcio com BRS Novaera, consórcio com BRS Xiquexique e cultivo solteiro) nas subparcelas. O sistema de consórcio (cultivo em faixas) foi constituído pela intercalação de faixas constituídas de quatro fileiras de feijão-caupi com faixas de quatro fileiras de milho. Ambas as culturas foram semeadas no espaçamento de 0,50 m entre fileiras. No cultivo consorciado, cada unidade experimental foi constituída... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Intercropping, which consists on growing of two or more crops at the same area at least in part of the cycle, focuses on the best use of available resources on property and minimizing the risk of yield loss. Maize growth intercropped with cowpea, which is relatively more tolerant to drought, mainly due to the shorter cycle, can be an interesting option as off-season crop. However, there are few and inconsistent research results on intercropping maize with cowpea, especially in the Midwest and Southeast of Brazil. Therefore, the objective of this work was to evaluate the cowpea as monoculture, and intercropping different cultivars of cowpea with a variety and a single cross hybrid of maize, in Dourados-MS and Botucatu-SP. The experiment was a randomized complete block design with split-plots arrangement and four replications. For the cowpea crop, were considered three cropping systems/cultivars of maize (intercropped with maize variety (BR 473), intercropped with maize hybrid (BRS 1030 or 1010) and cowpea sole crop) in the plots, and three cowpea cultivars (BRS Guariba, BRS Novaera and BRS Xiquexique) in the subplots. For the maize crop, were considered two maize cultivars (BRS 473 and BRS 1030 or BRS 1010) in the plots, and four cropping systems/cultivars of cowpea (intercropped with BRS Guariba, intercropped with BRS Novaera, intercropped with BRS Xiquexique and maize sole crop) in the subplots. Intercropping system was designed by intercalating strips constituted by four rows of cowpea with strips with four rows of maize. Both crops were sown at 0.50 m row spacing. In the intercropping system, each experimental unit consisted of eight rows with 6 m in length, in other words, four rows of maize and four rows of cowpea. In the sole crop, each experimental... (Complete abstract click electronic access below) / Orientador: Rogério Peres Soratto / Coorientador: Gessi Ceccon / Banca: Carlos Alexandre Costa Crusciol / Banca: Maurisrael de Moura Rocha / Mestre

A multiplicidade semântica, isto é, o fato de uma forma linguística apresentar mais de um significado ou nuance contextual, é um fenômeno que, apesar de não trazer grandes problemas à comunicação cotidiana, impõe diversas questões às teorias semântico-lexicais e a suas aplicações linguísticas. Neste trabalho, buscamos compreender o tratamento dispensado à multiplicidade semântica por learners’ dictionaries do inglês (dicionários monolíngues para aprendizes avançados de inglês como língua estrangeira) à luz do quadro teórico da Semântica Cognitiva Lexical. Em um primeiro momento, sistematizamos as implicações trazidas pela multiplicidade semântica para os learners’ dictionaries, principalmente no que diz respeito aos procedimentos de lumping e splitting, ao tipo de solução adotada para a divisão de verbetes para as formas lexicais (homonímica ou polissêmica) e aos critérios de organização das acepções nos verbetes. Com relação a esses aspectos, demonstramos que não há uma base teórica sólida que permita definir quantos e quais significados um item lexical apresenta, que não há consenso quanto ao tratamento das soluções nesse tipo de dicionário e que a frequência – critério utilizado pelas obras para organizar as acepções – não é tão objetivo quanto se esperaria, nem tem respaldo empírico para a utilização nesse tipo de dicionário. Assim, defendemos que, por conta do caráter interpretativo da descrição semântico lexical, evidenciada pela flexibilidade no tratamento dispensado pelas obras às questões da multiplicidade semântica, seja buscada uma abordagem distinta a essas questões. Com esse intuito, em um segundo momento, introduzimos a concepção semântico-cognitiva de estrutura semasiológica, que, ancorada em postulados da Teoria Prototípica, destaca a sobreposição e a saliência semântica como características estruturais do léxico, postulados que contemplam a flexibilidade e a instabilidade do significado lexical. Na busca por subsídios metodológicos que fundamentem uma proposta alternativa aos problemas lexicográficos, apresentamos alguns dos modelos de descrição da estrutura semântica dos itens lexicais propostos pelo paradigma cognitivo: o Modelo Radial, o Modelo Esquemático e o Modelo de Grupos em Sobreposição. Avaliamos a estrutura semasiológica do item lexical case e propomos formas alternativas para sua representação nos learners’ dictionaries que condizem tanto com os postulados semântico-cognitivos, quanto com o que se sabe sobre o tipo de dicionário em questão e as necessidades de seus usuários. Com relação às soluções homonímica e polissêmica, sugerimos quatro configurações possíveis que permitem representar a estrutura coesa da polissemia, mas cuja validação depende ainda de testes de uso. Quanto à organização das acepções, consideramos que, mesmo através do uso de uma estrutura hierárquica, é possível representar os fenômenos de sobreposição e saliência semântica que julgamos relevantes para os usuários dessas obras, por exemplo, através do uso dos próprios recursos possibilitados pela hierarquia e da redação de definições que destaquem atributos compartilhados por dois ou mais significados que não podem ser relacionados na estrutura linear do verbete. Assim, uma abordagem semântico-cognitiva parece ser útil para nortear práticas lexicográficas relativas à estruturação das informações sobre a multiplicidade semântica nos learners’ dicitionaries. / Semantic multiplicity can be defined as a case in which a single linguistic form presents more than one meaning or contextual reading. Even though this phenomenon usually does not pose serious challenges for everyday communication, it certainly brings about important issues to lexical semantic theories and its linguistic applications. The present dissertation aims at evaluating the treatment semantic multiplicity receives in English monolingual advanced learners’ dictionaries from a cognitive-semantic point of view. Therefore, the consequences of semantic multiplicity for the organization of learners’ dictionaries are presented, mainly with regard to the procedures of lumping and splitting, the solutions applied for structuring entries (homonymic or polysemous solutions), and the criteria used in arranging senses. First, it is demonstrated that there are no solid methodological bases on which to decide on how many (nor which) senses a lexical item has. Second, it is shown that there is no agreement on the solution to be applied to this type of dictionary. Third, it is advocated that the criterion used for sense arrangement (frequency) is not as objective as one would expect and it has not yet been proven to bring any advantage for the users of learners’ dictionaries. Because of the interpretative nature of lexical semantic description, which is reflected in the different treatments the dictionaries provide to these matters, a distinct approach is sought. To this end, the cognitive-semantic conception of semasiological structure is introduced. With its origins linked to Prototype Theory tenets, this notion highlights that semantic salience and overlapping are structural characteristics of the lexicon, which reflect the flexibility and instability of lexical meaning. In order to search for methods that could ground an alternative proposal for these lexicographic issues, the cognitive-semantic descriptive models of semantic structure are assessed: the radial model, the schematic model, and the overlapping sets model. The semasiological structure of the lexical item case is described and a new proposal for its organization is provided, in tune with cognitive-semantic tenets and with what is known about this type of dictionary and its users’ needs. Regarding homonymic and polysemous solutions, four different arrangements are suggested, which represent the coherent structure of polysemy. Regarding sense arrangement, it is shown that even through the use of a hierarchical structure, it is possible to represent the semantic overlapping and salience found to be useful for the users of learners’ dictionaries. By exploring the hierarchical resources themselves and by manipulating the wording of definitions, it is feasible to accentuate attributes shared by two or more senses that cannot be related in the linear structure of the dictionary entry. Thus, Cognitive Semantics presents itself as a useful approach to guide lexicographic practices related to the structuring of semantic multiplicity information in learners’ dictionaries.

The crucial role of representation in mathematical and statistical modeling and problem solving as evident in learners' arrangement and representation of statistical data were investigated with focus points data arrangement, data representation and statistical thinking levels. The representation tasks required learners to arrange and represent data through modeling, focusing on spontaneous representations. Successful transnumeration determine the ultimate success of a representation and the ability to organise data is regarded as critical. Arrangement types increased in sophistication with increased grade level and the hierarchical nature of arrangement types became apparent when regarded in the context of an adapted SOLO Taxonomy framework. A higher level arrangement strategy pointed to a higher SOLO level of statistical thinking. Learners in the two tasks produced a rich variety of representations which included idiosyncratic, unsophisticated responses as well as standard statistical representations. The context of the two tasks, the quantitative versus qualitative nature of the data in the tasks, and the statistical tools or representational skills learners have at their disposal, played an important role in their representations. Well-planned data handling activities develop representational and higher order thinking skills. The variety of responses and different response levels elicited in the two tasks indicate that the nature of the tasks rather than the size of the data set play a conclusive role in data tasks. Multiple representations by an individual were an indication of successful modeling, are effective in problem solving and are associated with good performance. The SOLO model which incorporates a structural approach as well as a multimodal component proved valuable in the analysis of responses. Using this model with accompanying acknowledgement of different problem solving paths and the contribution of ikonic support in the concrete symbolic mode, promote the in-depth analysis of responses. This study contributes to the research in the field of data representation and statistical thinking. The analysis and results led to an integrated picture of Grade 4-7 learners' representation of statistical data and of the statistical thinking levels evident in their representations. / Educational Studies / D. Ed. (Didactics)