1,721,024 research outputs found
Anti-polio vaccinations in the third millennia
No full textPoliomyelitis is a highly infectious viral disease, which mainly affects young children. In 1988, the World Health Assembly adopted a resolution that committed all countries to polio eradication by the year 2000, launching the Global Polio Eradication Initiative. The last naturally occurring case of wild polio virus type 2 infection was in October 1999 while the last case of wild polio virus type 3 was recorded in November 2012. In 2016 there were the lowest number of polio cases in recorded history (just 37) and this year we expect even fewer cases. Until the end of October 2017 only 12 cases were reported (the previous year, in this same period, 27 cases had been recorded). The eradication program did not progress smoothly: fundamentalism; religious opposition; civil war; outbreaks of other infectious diseases and circulating vaccine-derived polioviruses may favor the failure of vaccination programs. Through the enormous progress toward polio eradication made in these last years, such as the switch from the trivalent oral poliovirus vaccine to the bivalent oral poliovirus vaccine and the certification of the eradication of the wild polio virus type 2; the eradication efforts are at their final chapter, otherwise known as the polio endgame
Objectifs de recherche et problèmes posés par l'évolution démographique des environs de la ville de Bologne du XVIIIe siècle au XIXe siècle
No full textBellettini Athos, Predi R., Schiaffino Andrea, Tassinari F. Objectifs de recherche et problèmes posés par l'évolution démographique des environs de la ville de Bologne du XVIIIe siècle au XIXe siècle. In: Annales de démographie historique, 1972. Techniques et méthodes. Actes du colloque de Florence, 1er-3 octobre 1971. pp. 193-196
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Le trasformazioni della struttura industriale delle regioni italiane. Analisi delle fonti e problemi di metodo
No full textEnhanced Electrochemical Water Splitting with Chiral Molecule-Coated Fe3O4 Nanoparticles
Full text linkPhotoelectrochemical (PEC) water splitting is a promising approach for generating hydrogen from water. In order to enhance PEC water splitting efficiency, it is essential to inhibit the production of the hydrogen peroxide byproduct and to reduce the overpotential required by an inexpensive catalyst and with high current density. In the past, it was shown that coating TiO2 electrodes by chiral molecules or chiral films enhances the hydrogen production and reduces the production of H2O2 byproduct. This was explained to be a result of the chiral-induced spin selectivity (CISS) effect that induces spin correlation between the electrons transferred to the anode. However, typically the current observed in those studies was in the range of 1-100 μA/cm2. Here we report currents in the range of 10 mA/cm2 obtained by adsorbing chiral molecules on a well-established Fe3O4 nanoparticle (NP) catalyst deposited on the anode. The results indicate a new strategy for designing low-cost earth-abundant catalysts where the advantages of the CISS effect are combined with the large effective area provided by the NPs to promote PEC water splitting with high current density
Magnetoelectrochemistry and asymmetric electrochemical reactions
Full text linkMagnetoelectrochemistry is a branch of electrochemistry where magnetic fields play a vital role in the oxidation and reduction process of the molecules. When it comes to spin-dependent electrochemistry (SDE), becomes a new paradigm. This work presents electrochemical response during the “chiral imprinting” on working electrodes and the effects of potentiostatic and galvanostatic methods. We explore the use of the SDE concept, which is implemented for chiral-ferromagnetic (CFM) hybrid working electrodes, and we compare various electrochemical parameters affecting the quality of deposition. We electrochemically co-deposited nickel (Ni) with a chiral compound (tartaric acid) in its enantiopure forms (L and D), which allows us to obtain a chiral co-deposited nickel-tartaric acid (Ni-LTA or Ni-DTA) working electrode
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