1,721,235 research outputs found
Primo convegno nazionale degli studenti di antropologia, preistoria e protostoria: Ferrara, 8-10 maggio 2004. Riassunti
No full textRiassunti del Primo Convegno Nazionale degli Studenti di Antropologia, Preistoria e Protostoria svoltosi a Ferrara, 8-10 Maggio 2004
Distribution of endemic and alien plants along Mediterranean rivers: a useful tool to identify areas in need of protection?
No full textThe main aim was to obtain information about the more critical sectors of Mediterranean-type rivers, especially in the islands where the percentage of endemic species is high, even in riparian habitats. Our hypothesis was that endemic and alien species, considered important in defining conservation priorities along rivers, have different patterns of distribution and their coexistence indicates human impacts on fluvial systems, which can cause natural habitat loss. Generalized Additive Models were used to model the distribution patterns of endemic and alien species along the longitudinal gradient. They showed that endemic species were linked to the most natural areas in the middle and upper sections of the rivers, whereas the distribution of aliens in middle and lower sections can be regarded as a consequence of human impact. This finding underlined the presence in the middle sections of the rivers of areas with important floristic features that are also affected by alien species. What currently seems a situation of equilibrium turns out to call for careful control, first and foremost, by maintaining riparian vegetation. Our results highlighted the utility of our method for rapidly obtaining information about the criticalities of rivers in Mediterranean biodiversity hotspots. © 2013 Académie des sciences
An integrated approach to support a river ecological network: A case study from the Mediterranean
Full text linkRiverine ecosystems are among the most impacted ecosystems worldwide since they are exposed to multiple stressors. Land Use/Land Cover (LULC) changes is the main human imprint on those ecosystems whose spatiotemporal habitat destructions pose a threat to biodiversity, ecosystem integrity and ecological processes. The most important statutory instruments for riverine ecosystem protection, conservation and restoration in the European Union are the Water Framework Directive (WFD) and the Habitats and Birds Directive (HBDs). In this study, we develop a methodological framework to spatially link the ecological integrity of river sub-basins with the protected areas therein, taking into account the influence of land use as expressed in the WFD. We combined a multi-criteria evaluation approach using six of the most frequently applied criteria for conservation evaluation to assess river basin integrity (RBI) index at the sub-basin level, and used as a proxy for functional connectivity categories. In addition, we used the distance of every sub-basin from the surrounding Natura 2000 sites as a measure of structural connectivity. Using ecological network design principles (i.e. Core areas; Corridors; Stepping Stones; Buffer areas; and Restoration areas), we incorporated the two aspects of connectivity into a framework, which links river management at the basin level with the site level assessment as dictated by the HBDs. We implemented this framework in a Mediterranean river basin located in Southern Tuscany, which is part of the Natura 2000 network. Six of the sub-basins (20%) have high functional connectivity, 14 sub-basins (47%) medium and 10 sub-basins (33%) low functional connectivity. Structural connectivity of the study area followed the same tendency as that of functional connectivity, with the majority of the sub-basins having medium connectivity (57%; 17 sub-basins), and 23% (7 sub-basins) and 20% (6 sub-basins) high and low structural connectivity respectively. As a result, six of the sub-basins were characterised as corridor areas while the majority of the sub-basins were identified as buffer areas (57%). Two sub-basins were characterised restoration areas and one as stepping stone (SS). Our approach is one of many plausible ecological networks, which although analytically simple, can be enriched with data on species and stakeholders' involvement
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The reaction to nailing or cementing of the femur in rats. A microangiographic and fluorescence study.
No full textBone reaction to cement and to a cementless stem was studied in the rat femur with histological fluorescence and microangiographic techniques. Periosteal and endosteal apposition, and consequent remodelling, appeared as a reaction to reaming rather than caused by cement or a cementless stem. Every change in bone began with proliferation, progression and orientation of the vessels. Endosteal apposition was absent in cemented femurs because the entire medulla was occupied by the acrylic cement, but remodelling of the subendosteal cortex followed medullary revascularisation which was far advanced after 90 days. In cementless stems, endosteal apposition of primary woven bone and remodelling was the basis for bony ingrowth and anchorage through bony bridges. Our results suggest that the pattern of blood supply is relevant to the structural organisation of mature lamellar bone around the implant. Cemented stems have maximum anchorage and stability as soon as they are inserted, but this decreases with time as revascularisation occurs. Cementless stems can reach maximum integration later after insertion, and revascularisation is less critical because they usually do not fill the canal completely
THE FOREIGN THEORETICAL INFLUENCE IN ITALY VS THE DOUBLE-ENTRY METHOD. THE ACCOUNTING ACTIVITIES OF “SANTISSIMA ANNUNZIATA” HOSPITALS IN ABRUZZO (XVIII-XIX CENTURIES)
No full textThe effects of mechanical forces on bones and joints. Experimental study on the rat tail.
No full textWe have used an experimental model employing the bent tail of rats to investigate the effects of mechanical forces on bones and joints. Mechanical strain could be applied to the bones and joints of the tail without direct surgical exposure or the application of pins and wires. The intervertebral disc showed stretched annular lamellae on the convex side, while the annulus fibrosus on the concave side was pinched between the inner corners of the vertebral epiphysis. In young rats with an active growth plate, a transverse fissure appeared at the level of the hypertrophic cell layer or the primary metaphyseal trabecular zone. Metaphyseal and epiphyseal trabeculae on the compressed side were thicker and more dense than those of the distracted part of the vertebra. In growing animals, morphometric analysis of hemiepiphyseal and hemimetaphyseal areas, and the corresponding trabecular bone density, showed significant differences between the compressed and distracted sides. No differences were observed in adult rats. We found no significant differences in osteoclast number between compressed and distracted sides in either age group. Our results provide quantitative evidence of the working of 'Wolff's law'. The differences in trabecular density are examples of remodelling by osteoclasts and osteoblasts; our finding of no significant difference in osteoclast numbers between the hemiepiphyses in the experimental and control groups suggests that the response of living bone to altered strain is mediated by osteoblasts
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
