582 research outputs found

    Variational Principles and Conservation Conditions in Volterra's Ecology and in Urban Relative Dynamics

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    Contribution to the Metropolitan Study: 14 -- From an analytical viewpoint, Volterra's variational principles and their associated integrands in single and multiple species interaction under absolute growth conditions in the field of mathematical ecology are reconsidered and simplified. They are then compared with the conservation conditions found appropriate to hold in a class of dynamic problems of relative growth in urban analysis. The comparison assists in interpreting the integrands of geographical (spatial) associations as a "stationary effort fitness function" associated with a cumulative entropy measure of the relative urban dynamic spatial distributions. From a substantive viewpoint, the paper shows the theoretical conditions, which would result in all spatial activity to be concentrated into a single point, so that inferences can be made regarding the conditions under which the activity will disperse. It also demonstrates that assuming a particular problem formulation, in this case a relative dynamic framework in an inactive environment, will result in obtaining spatial competitive exclusion. This is demonstrated in a parsimonious manner

    Period-doubling in discrete relative spatial dynamics and the Feigenbaum sequence

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    AbstractIt is shown in this paper that although the period-doubling Feigenbaum sequence and the associated universal numbers in discrete maps of the logistic type hold over parameters, their true nature have them holding over slopes of the corresponding Poincaré maps. This finding enables one to find these Feigenbaum slope sequences in more complex maps. Further, it is demonstrated by an example in discrete relative growth spatial dynamics that a Feigenbaum sequence does not hold over the bifurcation parameter

    Account of Different Views in Dynamic Choice Processes

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    Series: Discussion Papers of the Institute for Economic Geography and GIScienc

    Economic structural change over time: Brazil and the United States compared

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    Usando as matrizes de insumo-produto para as economias do Brasil e dos Estados Unidos, este estudo comparativo tem como objetivo analisar como a estrutura produtiva de dois grandes países, com níveis diferentes de desenvolvimento, mudou através do tempo (1958-77 para os Estados Unidos e 1959-80 para o Brasil). A mudança na estrutura produtiva e decomposta em três componentes iniciais (demanda final, tecnologia, e sua interação sinergética), após o que estes componentes são divididos em mudanças que são iniciadas dentro e fora do setor. A partir destas analises e possível identificar os padrões de mudanças estruturais nas duas economias. Os resultados indicam um grande grau de semelhança nos padrões do processo de crescimento de ambos os países, com diferenças mais significantes entre setores do que entre países. A análise capaz de capturar diferenças importantes na origem das mudanças da demanda, isto e mudanças internas versus mudanças externas ao setor.Using input-output tables for the economies of Brazil and the United States, this comparative study focuses on changes in the economic structure of two large countries with different levels of development over time (1958-77 for the United States and 1959-80 for Brazil). The change in the economic structure is decomposed into three initial components (final demand, technology, and their synergistic interaction) and thereafter these components are further divided into change initiated within the sector and outside the sector. From this analysis it is possible to identify patterns of structural change in the two economies. The results indicate a rather remarkable degree of commonality in the patterns of growth processes in both countries, with more significant differences between sectors than between countries. The analysis confirmed earlier findings about the role of demand changes but was able to capture important differences in internal-to-sector versus external-to-sector sources of demand change

    Phase 1b/2a trial of the superoxide dismutase mimetic GC4419 to reduce chemoradiotherapy-induced oral mucositis in patients with oral cavity or oropharyngeal carcinoma

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    PURPOSE: To assess the safety of the superoxide dismutase mimetic GC4419 in combination with radiation and concurrent cisplatin for patients with oral cavity or oropharyngeal cancer (OCC) and to assess the potential of GC4419 to reduce severe oral mucositis (OM). PATIENTS AND METHODS: Patients with locally advanced OCC treated with definitive or postoperative intensity modulated radiation therapy (IMRT) plus cisplatin received GC4419 by 60-minute intravenous infusion, ending \u3c60 minutes before IMRT, Monday through Friday for 3 to 7 weeks, in a dose and duration escalation study. Oral mucositis was assessed twice weekly during and weekly after IMRT. RESULTS: A total of 46 patients received GC4419 in 11 separate dosing and duration cohorts: dose escalation occurred in 5 cohorts receiving 15 to 112 mg/d over 3 weeks (n=20), duration escalation in 3 cohorts receiving 112 mg/d over 4 to 6 weeks (n=12), and then 3 additional cohorts receiving 30 or 90 mg/d over 6 to 7 weeks (n=14). A maximum tolerated dose was not reached. One dose-limiting toxicity (grade 3 gastroenteritis and vomiting with hyponatremia) occurred in each of 2 separate cohorts at 112 mg. Nausea/vomiting and facial paresthesia during infusion seemed to be GC4419 dose-related. Severe OM occurred through 60 Gy in 4 of 14 patients (29%) dosed for 6 to 7 weeks, with median duration of only 2.5 days. CONCLUSIONS: The safety of GC4419 concurrently with chemoradiation for OCC was acceptable. Toxicities included nausea/vomiting and paresthesia. Doses of 30 and 90 mg/d administered for 7 weeks were selected for further study. In an exploratory analysis, severe OM seemed less frequent and briefer than expected

    Семинар «Комплексная судебно-баллистическая и судебно-медицинская экспертиза» (Москва)

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    The paper presents the outcomes of the seminar «Integrated Forensic Ballistics and Medical Examinations» hosted October 16–20, 2017 by the RFCFS of the Russian Ministry of Justice in MoscowПредставлены итоги семинара «Комплексная cудебно-баллистическая и судебно-медицинская экспертиза», прошедшего с 16 по 20 октября 2017 года в Москве на базе ФБУ РФЦСЭ при Минюсте Росси

    Linkages and Multipliers in a Multiregional Framework: Integration of Alternative Approaches

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    In this paper, two literatures that have explored the structure of economies are brought together. In the first case, the approaches to key sector identification (initially associated with Hirschman and Rasmussen) that were modified by Cella, Clements and Rossi and Guilhoto et al. to reveal what may be referred to a pure linkage approach are related to the concerns of Miyazawa and his identification of internal and external multiplier effects. While Miyazawa was interested mainly in identifying the sources of change in an economy, his approach shares considerable commonality with the new ideas in key sector identification in which a sector or set of sectors are separated from the rest of the economy. Hence, in both cases, a decomposition of the economy needs to be considered; the present paper reveals the similarity of perspective and provides the formal link between the two methodologies
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