117,400 research outputs found
Modelli in ceroplastica di Anfibi e Rettili nelle collezioni di Kosmos – Museo di Storia Naturale dell’Università di Pavia
No full textWax models of Amphibians and Reptiles in the Kosmos collections – Natural History Museum of the University of Pavia. Waxworking is a technique used since ancient times to create wax models but only since the 17th century was adopted for scientific purposes and in particular for anatomical studies. During the 19th century, zoological and botanical wax models were quite common in the collections of museums and universities for educational purposes. Kosmos holds 80 waxworks from the former Museum of Comparative Anatomy and Physiology. The oldest specimens are three frog heart models and a series of snake heads, created by Angelo Maestri (1806-1889). More recent preparations were made by Achille Maestri including the development models of amphibians and sauropsida. Finally, there are 35 models purchased from Studio Ziegler company of Friborg which represent the entire development of an anuran amphibian and the formation of the primordial skull in Rana temporaria, Ambystoma mexicanum and Lacerta agili
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Il bullismo visto dai ragazzi.Un'indagine svolta nel territorio abruzzese.
No full textL'indagine svolta nel territorio abruzzese ha coinvolto quasi 5000 ragazzi delle scuole abruzzesi estratte a campione e ha interessato alunni delle ultime due classi delle elemntari, delle scuole medie e delle superiori.Ne è emerso un ampio quadro della dimensione del fenomeno, delle sue caratteristiche, della percezione da parte dei ragazzi in riferimento a norme, valori e attegiamenti
High- and low-flux acetate-free biofiltration: experimental assessment of calcium mass balance and intact parathyroid hormone behaviour.
No full textWe studied total calcium mass balance and plasma intact parathyroid hormone behaviour in 10 uraemic patients who underwent acetate-free biofiltration carried out in accordance with six different dialytic schedules, where either a polyacrylonitrile or a polysulphone membrane was used. Schedules 1 and 2 involved a reinfusion flow rate of 33.3 ml/min with a dialysate calcium concentration (DCa) of 1.75 and 2 mmol/l respectively; in schedule 3, 4, 5 and 6 reinfusion flow rate amounted to 50 ml/min and DCa was respectively of 1.75, 2, 2.25 and 2.5 mmol/l. Dehydration remained unchanged in all schedules: 700 g/h. Finally high- and low-flux acetate-free biofiltration are able to induce different Ca mass balance which may suit different therapeutic contexts. Ca mass balance was either positive or negative depending on reinfusion flow rate and DCa. With a reinfusion flow rate of 33.3 ml/min a DCa of at least 2 mmol/l was necessary to obtain a positive mass balance, while with a reinfusion flow rate of 50 ml/min DCa had to equal 2.25 mmol/l. In high-flux acetate-free biofiltration, the estimation of predialytic Ca2+ and DCa values, using a simple formula, allows prediction of the mass balance that will be attained. At the end of acetate-free biofiltration, intact parathyroid hormone always decreased when a polyacrylonitrile membrane was employed while it increased, in the presence of negative Ca mass balance with a polysulphone membrane
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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