There has been considerable progress in recent years in our understanding of the patterns of cortical bone loss in the second metacarpal in archeological skeletal samples. Nevertheless, cortical data from reference skeletal collections are insufficient, and the possible connection of metacarpal cortical parameters with osteoporotic fractures has not been thoroughly addressed. As such, this article aims to identify and explain sex‐specific and age‐associated metacarpal cortical bone loss in a large sample (N = 302; females: 154/males: 148) from the Coimbra Identified Skeletal Collection. Another objective is to evaluate the association of cortical and demographic features with osteoporotic fractures. Age‐related endocortical bone loss is significant in women but not evident in men. Periosteal accretion of the bone is absent in both sexes. Overall, there is a net loss of the cortical bone in women, whereas cortical bone strength seems to be preserved in men. The prevalence of osteoporotic fractures is similar in both sexes, with age at death significantly influencing the probability of exhibiting a fracture. Metacarpal cortical index does not seem to be an independent risk factor for osteoporotic fractures in this sample. 相似文献
The attractiveness of cities as places to live determines population movements into or out of them. Understanding the appealing features is fundamental to local governments, particularly for cities facing population decline. Pull and push attributes can include economic aspects, the availability of amenities and psychological constructs, initiating a discussion around which factors are more relevant for migration. However, such discussion has been underexplored in studies of shrinking cities. In the present study, we contribute to the discussion by identifying pull and push factors in Portuguese shrinking cities. Data were collected using a face-to-face questionnaire of 701 residents in four shrinking cities: Oporto, Barreiro, Peso da Régua and Moura. Factor analysis and automatic linear modelling were used to analyse the data. Our results show that the economic activity is the most relevant feature for retaining residents. However, characteristics specific to each city, related to heritage and natural beauty, are also shown to influence a city’s attractiveness. The cause of population shrinkage was also found to influence residents’ assessments of the pull and push attributes of each city. Furthermore, the results show the relevance of social ties and of place attachment to inhabitants’ intention to continue living in their city of residence. 相似文献
While the land use-street network nexus is well acknowledged, evidence for the one-way impacts of land-use patterns on street accessibility is still inadequate. The measurements of land-use patterns and street accessibility lack systematic knowledge. Their empirical correlations also lack geographical variability, constraining site-specific land-use practices. Therefore, this study overcame the aforementioned limitations by examining the two-level spatial models to formulate accessibility-oriented land plans, using a well-developed Chinese city as an example. Firstly, two landscape metrics—Euclidean Nearest-Neighbor Distance (ENN) and Similarity Index (SIMI)—were used to quantify the intra- and inter-land-use configurations, respectively. Both city-level and local accessibility were measured using spatial design network analysis. Performing both ordinary least squares (OLS) and geographically weighted regression (GWR) models, results identified the statistically significant effects of inter-land-use patterns on two-level street accessibility. An exception was that land-use configurations within residential and industrial regions were irrelevant to street accessibility. We also found GWR was a better-fitting model than OLS when estimating locally-varied accessibility, suggesting hierarchical multiscale land-use planning. Overall, locally heterogeneous evidence in this study can substantialize land use-street network interactions and support the decision-making and implementation of place-specific accessibility-oriented land use. 相似文献
Although there is a considerable amount of empirical evidence on inter-firm collaborations within technology-based industries, there are only a few works focussing on R&D cooperation by low-tech firms, especially small and medium-sized enterprises (SMEs). Providing further and new evidence based on a recently built database of CRAFT projects, this study analyses the relationship between technology and proximity in international R&D networks using HOMALS and statistical cluster techniques. The resulting typology of international cooperative R&D projects highlights that successful international cooperative R&D projects are both culturally/geographically closer and distant. Moreover, and quite interestingly, geographically distant projects are technologically more advanced whereas those located near each other are essentially low-tech. Such evidence is likely to reflect the tacit-codified knowledge debate boosted recently by the information and communication technology (ICT) “revolution” emphasized by the prophets of the “Death of Distance” and the “End of Geography”. 相似文献
Whales have long been an important part of Pacific Northwest Coast human subsistence and lifeways. Native peoples on the Oregon Coast were not known to hunt whales, but a humpback whale phalange with an embedded bone harpoon at the Par-Tee site (35CLT20) and ethnographic accounts raised the possibility of opportunistic whale hunting. We analyzed a suite of whale remains from Par-Tee and performed ancient DNA-based species identifications on 30 specimens. The assemblage includes gray whales (Eschrichtius robustus, 60.7% of the assemblage), humpbacks (Megaptera novaeangliae, 32.1%), minkes (Balaenoptera acutorostrata, 3.6%), and orcas (Orcinus orca, 3.6%). While the species composition is similar to those found in archaeological deposits from systematic whaling areas in Washington and Vancouver Island, bone modification patterns and element representation reveal important differences. Our analysis demonstrates that whales were likely a supplementary part of human subsistence at Par-Tee and, while opportunistic whale hunting likely occurred, it may have been secondary to scavenging and utilization of beached and/or drift whales. 相似文献
O’Gorman, J.P., Salgado, L., Varela, J., & Parras, A., 2013. Elasmosaurs (Sauropterygia, Plesiosauria) from the La Colonia Formation (Campanian–Maastrichtian), Argentina. Alcheringa 37, 257–265. ISSN 0311-5518. Elasmosaur postcranial remains from the La Colonia Formation (Campanian–Maastrichtian), Chubut Province, Patagonia, Argentina, are described. The new material has small dimensions and caudal vertebrae with parapophyses strongly projected laterally—characters shared with some Elasmosauridae indet. from the coeval Allen Formation, Río Negro Province, Argentina. These features reinforce the similarities between the plesiosaur faunas to the north and south of the Somún Curá Plateau. The small size of these elasmosaurs may be palaeoecologically related to the marginal marine depositional environment of the sedimentary host rocks. José P. O’Gorman [joseogorman@fcnym.unlp.edu.ar], División Paleontología Vertebrados, Museo de La Plata, Universidad Nacional de La Plata, Paseo del Bosque s/n., B1900FWA, La Plata, Argentina and [CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas)]; Leonardo Salgado [salgadoleito@yahoo.com.ar], Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, Isidro Lobo y Belgrano, 8332 General Roca, Argentina and [CONICET]; Julio Varela [julioadrianvarela@hotmail.com], and Ana Parras [aparras@exactas.unlpam.edu.ar], INCITAP (CONICET-UNLPam), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa, Uruguay 151, 6300 Santa Rosa, La Pampa, Argentina. Received 27.7.2012; revised 19.10.2012; accepted 27.10.2012.相似文献
This article examines the historical processes that shaped the development of archaeological practice in Angola during the Portuguese colonial period and the aftermath of political independence. Using published works, unpublished reports, and photographic records, we examine the research themes, actors, scholars, and institutions that influenced archaeological research in the country. We also used documents and museum collections in Angola and Portugal to create a GIS database of Angola’s archaeological findings. This study highlights the events, personalities, and priorities that motivated earlier investigations, and the geographical distribution of prehistoric sites. We hope this study will be a resource for guiding future archaeological research in Angola.