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11.
The research performed by Camillo Golgi in histology and pathology dates from 1865, the year in which he obtained his MD degree, to 1923, when his last scientific article was published. Beginning in the mid-1855s, microscope manufacturers in Europe started producing objectives based on the principle of immersion introduced in 1847 by Giovan Battista Amici. The immersion objectives greatly improved the resolution of microscopic observations at high magnifications. From 1860 to 1872, technological improvements in microscope optics and the practicality of their use provided a larger community of investigators effective tools needed to study the structure of the nervous system. This progress in microscopy was associated with the application of new histological techniques, mastered by the chromoargentic reaction introduced by Golgi in 1873. In 1872, further progress in microscopy stemmed from the application of notions of applied physics to the production of microscope optics. These developments in microscopy will be briefly reviewed here.  相似文献   
12.
This article presents the results of a 1991 household income survey of the three main groups in Cuban agriculture: wage workers on state farms, members of production co-operatives, and peasant producers. It is shown that since the 1959 revolution household income levels in the agricultural sector have improved dramatically, while regional differences have been ameliorated considerably. Households in the private sector of Cuban agriculture have fared the best. It is also demonstrated that agricultural households rely on multiple sources of income to generate their livelihood. Rather than being strictly proletarian, collective, or petty commodity producers, these households are best characterized by the multiple class relations in which they participate.  相似文献   
13.
The waters of Puerto Rico harbour the remains of thousands of years of human occupation. The island played a key role in the first decades of European exploration of the New World, and its coasts and estuaries have preserved an extensive record of the island's maritime history, before and after the arrival of the Europeans. The objective of this project is to study Puerto Rico's seafaring history through the investigation of its submerged cultural heritage, with a particular focus on the history of European shipbuilding. In 2008 the authors started with survey on the north coast.
© 2009 The Authors  相似文献   
14.
The rise of social assistance in Brazil has been remarkable. The 1988 Constitution signalled a renewed ‘social contract’ leading to citizenship‐based social assistance providing guaranteed income to older and disabled people in poverty. Municipal activism in the 1990s extended the provision of direct transfers to all households in poverty through Bolsa Escola and other programmes later consolidated into Bolsa Família. This article studies the origins and evolution of social assistance institutions in Brazil, paying due attention to the role of ideas and politics.  相似文献   
15.
The evolution of littoral palaeoenvironments in the southern Pampas region of Argentina towards the end of the early Holocene and the beginning of the mid Holocene is discussed, and the formation processes of the archaeological site of La Olla are analysed. This site is located in the intertidal zone of the present beach and is remarkably well-preserved. The human occupation at the site has been dated at between 7400 and 6480 yrs BP, and is interpreted as a place for the processing and consumption of the southern fur seal (Arctocephalus australis) and southern sea-lion (Otaria flavescens). It is concluded that biostabilization by microbial mats of the sedimentary structures and archaeological remains that developed and are present on the tidal flat prevented their erosion by wind, turbulence currents and waves. This is what has permitted the exceptional preservation of the site. On the basis of the analyses of one of the sectors of the site it can be concluded that the sedimentary succession of the La Olla site is the result of the coastal environmental changes during the early–mid Holocene in the pre-maximum transgressive episode. During this interval a tidal flat developed on the Pleistocene abrasion platform. Human occupation occurred during the formation of mixohaline marsh, an upper intertidal–lower supratidal zone ecosystem.  相似文献   
16.
We synthesize and discuss available isotopic data on Holocene guanaco samples from southern South America, extending from Tierra del Fuego Island to northern Patagonia and the Pampean region. We evaluate temporal and spatial tendencies on the basis of 91 samples (mainly based on δ13Ccollagen values), presenting implications for paleodietary research in archaeology. We conclude that there are no strong correlations with latitude in the macro-spatial scale, while there is a set of interesting patterns at smaller regional scales. These patterns lead us to evaluate the role of ecologic and topographic variables (e.g. canopy effect, variations in altitude, ecotones) in structuring isotopic variability. Finally, on the basis of the present analysis we suggest a number of hypotheses and perspectives for the use of stable isotopes as geographic tracers of guanaco distribution in the past, and specific implications for the paleodietary study of human samples.  相似文献   
17.

In this paper, we explore the heuristic potential of a set of ideas about the structural and functional complexity of systems, proposed in the 1990s by theoretical biologist Daniel McShea. In particular, we focus on the structural aspects of the complexity exhibited by social systems organized into low- and intermediate-level functional units (i.e., groups and teams). To address this subject, we describe a methodology suited for measuring the complexity in the organization of work in such systems, which is primarily based on hierarchical task analysis. With this methodology, we approach a concrete case study: the construction of megalithic monuments in late prehistoric Iberia (ca. 3800–1800 BC). On the basis of the analysis of the three best documented, most structurally, and functionally complex monuments built within each of the three periods under study (Late Neolithic, Copper Age, and Early Bronze Age), we found that there was a trend towards less complexity in work organization related to monument building from the Late Neolithic to the Early Bronze Age. We discuss the importance of these results in light of the existing models of social complexity in European Later Prehistory, concluding that a more balanced view of social processes would be obtained if we look at complexity as a property of every different social system integrated into the whole society, and not as an exclusive property of the latter.

  相似文献   
18.
Gustavo Esteva 《对极》2010,42(4):978-993
Abstract: Was the “Oaxaca Commune” an ephemeral insurrection, an explosion of popular rage, without enduring consequences? Was it a specific expression of autonomous movements, an experiment anticipating the direction some of them are taking? Or was it an isolated, singular episode of people's struggles? As yet we do not have enough of an historical perspective to fully appreciate the nature and impact of the events of 2006 in Oaxaca that attracted the world's attention. But it is worth exploring them and discussing a tentative hypothesis about their nature and meaning for autonomous movements in Mexico and beyond, when the gap between means and ends is closed and the shape of the struggle is also the shape of the society the struggle attempts to create. These provisional notes can thus be seen as an introduction to a research agenda.  相似文献   
19.
20.
Góis, F., Scillato-Yané, G.J., Carlini, A.A. & Guilherme, E. 2013. A new species of Scirrotherium Edmund & Theodor, 1997 (Xenarthra, Cingulata, Pampatheriidae) from the late Miocene of South America. Alcheringa 37, 175–186. ISSN 0311-5518.

A new species of Scirrotherium Edmund & Theodor (Pampatheriidae) is described: S. carinatum. This genus was previously represented by a single species, S. hondaensis Edmund & Theodor, 1997, recorded from the middle Miocene (Laventan) of Colombia. Pampathere remains are common in the ‘Conglomerado osífero’ (late Miocene) of the Ituzaingó Formation in the Paraná River cliffs of Entre Ríos, Chubut (Argentina) and Acre (Brazil). All of them were referred to Kraglievichia paranense, and they are mostly osteoderms. However, only a few of these specimens are strictly consistent with that species. The new species described herein differs from S. hondaensis in having very thin osteoderms with more elaborate ornamentation. The movable band (or imbricate) osteoderms have a sculptured exposed surface and a single transverse row of anterior foramina; the lateral margins are wider and also bear foramina, and the longitudinal central elevation is long and proximally wide, and forms a posteriorly raised crest. This elevation is delimited by a fairly broad and shallow depression on each side, separating the marginal elevation from the longitudinal central one. The exposed surfaces of fixed (or fused) osteoderms bear large and deep anterior foramina, the longitudinal central elevation and delimiting depressions are very pronounced. This new species increases the known diversity of the pampatheres from the ‘Conglomerado osífero’. Additionally, a new nomenclatural scheme for Pampatheriidae osteoderms is proposed.

Flávio Góis [goisf@fcnym]unlp.edu.ar], Gustavo Juan Scillato-Yané [scillato@fcnym.unlp.edu.ar], Alfredo Armando Carlini [acarlini@fcnym.unlp.edu.ar], Departamento Científico Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque, s/n, 1900, La Plata, Buenos Aires, Argentina and CONICET; Edson Guilherme [guilherme@ufac.br], Universidade Federal do Acre, Laboratório de Pesquisas Paleontológicas (LPP), BR 364, Km 04, 69.915-900. Rio Branco, AC, Brazil. Received 11.5.2012; revised 31.7.2012; accepted 4.9.2012 .  相似文献   
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