130,412 research outputs found
Schwartz correspondence for real motion groups in low dimensions
No full textFor a Gelfand pair (G, K) with G a Lie group of polynomial growth and K a compact subgroup, the Schwartz correspondence states that the spherical transform maps the bi-K-invariant Schwartz space S(K\G/K) isomorphically onto the space S(Sigma_D), where Sigma_D is an embedded copy of the Gelfand spectrum in R^ell, canonically associated to a generating system D of G-invariant differential operators on G/K, and S(Sigma_D) consists of restrictions to Sigma_D of Schwartz functions on R^ell. Schwartz correspondence is known to hold for a large variety of Gelfand pairs of polynomial growth. In this paper we prove that it holds for the strong Gelfand pair (Mn,SOn) with n=3,4. The rather trivial case n=2 is included in previous work by the same authors
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
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
"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.
Commentaire d'arrêt
No full textEncore une fois en l'espace de quelques années, la Cour suprême canadienne s'est occupée d'une question relative à la religion avec le jugement Bruker c. Marcovitz. Par une majorité de sept contre deux, elle a établi que les accords qui ont un contenu religieux ne sont pas exempts d'examen judiciaire et a condamné un individu de religion juive à payer des dommages-intérêts à son ex-épouse pour n'avoir pas tenu son engagement contractuel de concéder le divorce religieux. Le jugement Bruker c. Marcovitz qui fait l'objet de la présente note est un exemple de la tendance, montrée par la Cour suprême canadienne dans ses arrêts les plus récents dans la matière, à mettre l'accent sur la dimension multiculturelle de la liberté de religion, plutôt que sur la liberté de religion en tant que droit individuel.Abstract : Once again in the space of a few years, the Supreme Court of Canada has dealt with a matter concerning religion in the decision Bruker v. Marcovitz. By a 7-2 majority, the Court ruled that agreements having a religious object are not exempt from judicial scrutiny and condemned a Jewish man to pay his ex-wife damages to compensate for losses arising from his refusal to provide her with a religious divorce, as he had contractually agreed. This decision is an example of the tendency, shown by the Canadian Supreme Court in its recent decisions on matters of this nature, of stressing the multicultural dimension of freedom of religion rather than as an individual right
One-to-one comparison between digital spot compression view and digital breast tomosynthesis
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Mammographic density estimation: one-to-one comparison of digital mammography and digital breast tomosynthesis using fully automated software.
No full textTo compare breast density on digital mammography and digital breast tomosynthesis using fully automated software.Following institutional approval and written informed consent from all participating women, both digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) were obtained. Breast percentage density was calculated with software on DBT and FFDM.Fifty consecutive patients (mean age, 51 years; range, 35-83 years) underwent both FFDM and DBT. Using a method based on the integral curve, breast density showed higher results on FFDM (68.1 ± 12.1 for FFDM and 51.9 ± 6.5 for DBT). FFDM overestimated breast density in 16.2\% (P < 0.0001). Using a method based on maximum entropy thresholding, breast density showed higher results on FFDM (68.1 ± 12.1 for FFDM and 51.9 ± 6.5 for DBT). FFDM overestimated breast density in 11.4\% (P < 0.0001). There was a good correlation among BI-RADS categories on a four-grade scale and the density evaluated with DBT and FFDM (r = 0.54, P < 0.01 and r = 0.44, P < 0.01).Breast density appeared to be significantly underestimated on digital breast tomosynthesis.Breast density is considered to be an independent risk factor for cancer Density can be assessed on full-field digital mammography and digital breast tomosynthesis Objective automated estimation of breast density eliminates subjectivity Automated estimation is more accurate than BI-RADS quantitative evaluation Breast density may be significantly underestimated on digital breast tomosynthesis
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