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ABSTRACT. The addition of output variation benefits to the users' surplus generated by transportation improvements has been subject to debate, and no agreement has been reached. In this paper, the problem is restated at the level of the origins of transportation demand, which can be derived from the information provided by the economic activity. It is shown that a competitive productive environment makes the transportation consumers' surplus exactly equal to the net economic benefits provoked in the products' markets; however, when monopolistic production prevails, the users' surplus may not reflect the benefits to the economy with accuracy. Mixed conditions are also explored and the role of final products' demand elasticity is highlighted. Different styles of welfare analysis are recommended for different market conditions.  相似文献   
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The benefits of urban open spaces for improving the quality of life and sustainability in cities are widely recognized. The functions they perform within the framework established by urban planning, as well as their metrics, are now more complex than in the past. It is convenient to develop methodologies for the evaluation of these spaces adapted to the present time to check their level of efficiency, which is useful in urban planning for the establishment of new urban open spaces. The aim of this study is to classify such spaces through a methodology that integrates spatial analysis, configuration analysis, and decision support so as to understand their complexity from a more advanced analytical perspective. In order to do this, a prior exploration of specific literature is carried out, which allows the characterization of the functions of urban open spaces by means of the corresponding analysis variables in a weighted manner. The integrated combination of these advanced tools is a step forward in achieving consistent and detailed results for urban open spaces. They perform their functions best in dense, central, equipped, accessible, connected, and easily walkable urban environments. In addition, future recommendations are provided.  相似文献   
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The ground penetrating radar (GPR) technique was used to investigate the subsurface in an urban area located in Mesagne (Italy) to obtain a map of the archaeological features in the ground. The GPR survey was undertaken at selected locations placed near (about 50 m) to a necropolis dating from the Messapian to the Roman imperial age, using a GSSI Sir System 2 incorporating 200 and 500 MHz centre frequency antennae. The selected areas (A and B) were surveyed along parallel 1 m spaced profiles using a 200 MHz antenna in area A and along parallel 0.5 m spaced profiles using a 500 MHz antenna in area B. For the selected areas the processed data were visualised in 3D space not only by means of the standard time slice technique, but also by means of a recently proposed approach, namely by iso-amplitude surfaces of the complex trace amplitude. The immediacy in revealing the spatial positioning of highly reflecting bodies, such as the anomaly interpreted as an old hypogeum room in area A, makes 3D visualisation techniques very attractive in archaeological applications of GPR. Their sensitivity to the signal/noise ratio is, on the other hand, highlighted by the quite poor performance in area B, where the only reliable result provided by all the techniques was the ancient living surface reflection, whereas none of them could effectively enhance the visibility of weak hyperbola reflections noted on 2D sections and probably related to the walls located on the ancient living surface. The performance of the various techniques in these two different situations allowed insights into their main advantages and drawbacks to be gained.  相似文献   
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Recent research in Paleolithic archeology has stressed the importance of temporal issues in assemblage interpretation. Archeological assemblages are temporal constructs, formed by the addition of an unknown number of depositional events. This temporal dimension is also evident at the artifactual level, since single artifacts may undergo different events of modification and/or uses over time. The recycling of previously discarded blanks for tool production is one of the best examples of the temporal nature of artifacts. The aim of this paper is to evaluate the importance of recycling in a Late Upper Paleolithic site, examining a type of artifact – burned tools – that has up to now been little used to approach this issue. Our results suggest that recycling was probably a significant component of Upper Paleolithic provisioning behavior, with important implications in site formation processes and the typological variability of assemblages. The expedient or curated character of recycling is also discussed.  相似文献   
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El artículo analiza la relación entre el reformismo borbónico y el desarrollo de espacios públicos de deliberación sobre asuntos de interés común en la ciudad de La Plata, la sede de la real audiencia de Charcas (hoy Sucre), hacia fines de la década de 1770. Se exploran un conjunto de luchas en torno a cuestiones críticas al programa reformista, tales como los recortes a las potestades del ayuntamiento, las preeminencias ceremoniales, el monopolio del tabaco y los medios legítimos de resolución de conflictos entre gobernantes y gobernados. Como resultado, se genera una politización de las relaciones de mando y obediencia, la multiplicación de controversias en diversos ámbitos donde se desenvolvía la vida pública y la difusión de pasquines como medio de propagación de opiniones contestatarias. Argumentamos que este proceso terminó por poner en cuestión tanto los fundamentos ideológicos como las condiciones de posibilidad de las políticas absolutistas.  相似文献   
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Explaining how the monumental statues (moai) of Easter Island were transported has remained open to debate and speculation, including their resource expenditures and role in deforestation. Archaeological evidence including analysis of moai variability, particularly those abandoned along ancient roads, indicates transport was achieved in a vertical position. To test this proposition we constructed a precise three-dimensional 4.35 metric ton replica of an actual statue and demonstrate how positioning the center of mass allowed it to fall forward and rock from side to side causing it to ‘walk.’ Our experiments reveal how the statue form was engineered for efficient transport by a small number of individuals.  相似文献   
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Martinelli, A.G., Bogan, S., Agnolin, F.L., Ribeiro, L.C.B., Cavellani, C.L., Ferraz, M.L.F. & Teixeira, V.P.A., iFirst article. First fossil record of amiid fishes (Halecomorphi, Amiiformes, Amiidae) from the Late Cretaceous of Uberaba, Minas Gerais State, Brazil. Alcheringa, 1–9. ISSN 0311-5518.

The first fossil amiid fishes (Halecomorphi, Amiiformes) from the Late Cretaceous Marília Formation (Bauru Group) at Uberaba County, Triângulo Mineiro region (Minas Gerais State, Brazil), are described. The material includes some partial maxillae, a dermopterotic, a cleithrum, several vertebral centra and teeth. Features such as the absence of a supramaxillary notch on the dorsal edge of the maxilla, a wide and deep pit on the maxilla for the articulation of the premaxilla, anterior portion of the maxilla with a sub-circular cross-section, teeth with acrodine cup with strong mesial and distal keels, among others, permit confident referral of the material to the Subfamily Vidalamiine (Amiidae), previously recognized in Lower Cretaceous strata of northeasthern Brazil. These specimens constitute the first Late Cretaceous record of this group in Brazil and one of the few in South America.

Agustín G. Martinelli [agustín_martinelli@yahoo.com.ar], Centro de Pesquisas Paleontológicas Llewellyn Ivor Price, Complexo Cultural e Científico Peirópolis (CCCP/UFTM), BR-262, Km 784, Bairro Peirópolis, Uberaba, Minas Gerais, Brazil; Sergio Bogan [sergiobogan@yahoo.com.ar], Fundación de Historia Natural ‘Félix de Azara’, Departamento de Ciencias Naturales y Antropología, CEBBAD—Universidad Maimónides, Hidalgo 775 piso 7 (1405BDB), Buenos Aires, Argentina. Federico Agnolín* [fedeagnolin@yahoo.com.ar], Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’, Av. Ángel Gallardo 470 (C1405BDB), Buenos Aires, Argentina. Luiz Carlos Borges Ribeiro [lcbrmg@terra.com.br], Camila Lourencini Cavellani [camila@patge.uftm.edu.br], Mara Lúcia da Fonseca Ferraz [mara@patge.uftm.edu.br] and Vicente de Paula Antunes Teixeira [vicente@patge.uftm.edu.br], Centro de Pesquisas Paleontológicas Llewellyn Ivor Price, Complexo Cultural e Científico Peirópolis (CCCP/UFTM), BR-262, Km 784, Bairro Peirópolis, Uberaba, Minas Gerais, Brazil. *Also affiliated with: Fundación de Historia Natural ‘Félix de Azara’, Departamento de Ciencias Naturales y Antropología, CEBBAD—Universidad Maimónides, Valentín Virasoro 732 (C1405BDB), Buenos Aires, Argentina. Received 15.4.2012; revised 11.6.2012; accepted 20.6.2012.  相似文献   
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