177,059 research outputs found
Alginate-polymethacrylate hybrid hydrogels for potential osteochondral tissue regeneration
No full textPorous scaffolds based on alginate-polymethacrylate hybrid hydrogels intended for bone and cartilage regeneration
were prepared through controlled calcium ions diffusion from an agar mould. The double interconnected
network of such materials combines into a single porous structure maintained by both noncovalent
crosslinks (calcium ions for alginate) and covalent crosslinks (polymethacrylate crosslinked by the addition of
mixtures of mono and bifunctional monomers). The alginate component ensures the appropriate micro-environment
to mimic the extra-cellular matrix, whereas the polymethacrylate improves the mechanical performances
of the hybrid hydrogels, helping to overcome the mechanical limitations of the alginate component.
Morphological characterization and porosity analysis of the hybrid scaffolds were assessed by scanning electron
microscopy and micro-computed tomography. Relative concentration and distribution of calcium ions were
evaluated by atomic absorption and dispersive X-ray analysis, respectively. Uniaxial compressive mechanical
tests were conducted to evaluate the compressive elastic modulus of the hybrid hydrogels that was correlated
with their swelling ratio and crosslinking degree. As was envisaged a much higher modulus (about seven times)
was obtained for the hybrid Alg/HE hydrogel than with alginate alone
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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Shotgun sequencing of honey DNA can describe honey bee derived environmental signatures and the honey bee hologenome complexity
No full textHoney bees are large-scale monitoring tools due to their extensive environmental exploration. In their activities and from the hive ecosystem complex, they get in close contact with many organisms whose traces can be transferred into the honey, which can represent an interesting reservoir of environmental DNA (eDNA) signatures and information useful to analyse the honey bee hologenome complexity. In this study, we tested a deep shotgun sequencing approach of honey DNA coupled with a specifically adapted bioinformatic pipeline. This methodology was applied to a few honey samples pointing out DNA sequences from 191 organisms spanning different kingdoms or phyla (viruses, bacteria, plants, fungi, protozoans, arthropods, mammals). Bacteria included the largest number of species. These multi-kingdom signatures listed common hive and honey bee gut microorganisms, honey bee pathogens, parasites and pests, which resembled a complex interplay that might provide a general picture of the honey bee pathosphere. Based on the Apis mellifera filamentous virus genome diversity (the most abundant detected DNA source) we obtained information that could define the origin of the honey at the apiary level. Mining Apis mellifera sequences made it possible to identify the honey bee subspecies both at the mitochondrial and nuclear genome levels
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
Metodologie integrate per la conoscenza, la tutela e la rappresentazione dell’architettura militare storica. Sistemi costruttivi e percorsi voltati lungo i bastioni occidentali di Cagliari (Sardegna, Italia)
No full textThe integrated method is been applied in the meet point between the curtain of Santa Chiara and the curtain of de Cardona, in a limited area of the ancient walls of Cagliari (Sardinia, Italy). The sector consists of a bastion called “curtain of Santa Chiara” designed in 1575 and realized in the period 1575-1578 by the military engineer Giorgio Paleari and the “curtain of de Cardona”, a military work commissioned by the Viceroy in the 1930s of the same century and interested by modification until the seventeenth century.
The archive documents offer a lot of informations on the presence of gunboats and vaulted passages designed and built in this area during this period. This source –accompanied by an architectural survey of the existing military work and the knowledge of the construction techniques used at the time and indicated in the military treaties– may direct a subsequent investigation with geophysical methods.
To this aim, a first graphic representation of the study area in the sixteenth century is proposed
Alginate-polymethacrylate hybrid hydrogels with double ionic and covalent network for tissue engineering
No full textLetter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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