118,580 research outputs found
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
Estrogen receptor alpha polymorphisms and fertility in populations with different reproductive patterns.
No full textThe estrogen receptor (ER) plays an important role in mediating estrogen action on target tissues. ER-alpha, the most abundant, is
found in all human reproductive tissues and studies on alpha-ER knockout mice have highlighted its role in reproduction.
ER-alpha gene (ESR1) polymorphisms have been associated with a variety of disorders including human infertility. In this
study, we examined the association of ESR1 PvuII and XbaI polymorphisms with fertility in two populations with different reproductive
patterns and precisely in a sample of healthy Italian men and women (n 5 178) and in a sample of healthy African-Ecuadorian
women (n 5 57). ESR1 xx and ppxx genotypes among the Italian men were found to be associated with an above-median
number of children (P 5 0.01 and P 5 0.004, respectively). ESR1 pp genotype among the Italian women showed a tendency to be
associated with a lower number of abortions (P 5 0.04), whereas ESR1 pp and ppxx genotypes among African-Ecuadorian women
were associated with a higher number of children (P 5 0.02 and P 5 0.03, respectively). These results are consistent with previous
observations indicating a role of ESR1 genotypes in human infertility and give insight into the complex interactions between genotypes
and reproductive behaviours in human populations
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
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
New nomenclatural combinations in vascular plants
No full textIn this paper the following new nomenclatural combinations are proposed: Descurainia suffruticosa (Coste & Soulié) Aymerich & L. Sáez, Linum suffruticosum subsp. castroviejoi (Mart. Labarga, Pedrol & Muñoz Garm.) L. Sáez & P. Aymerich, Oeosporangium acrosticum (Balb.) L. Sáez & P. Aymerich, Oeosporangium ×kochianus (Rasbach, Reichst. & Schneller) L. Sáez & P. Aymerich and Valeriana tarraconensis (Pau) L. Sáez & Aymerich.En aquesta aportació es proposen les següents noves combinacions nomenclaturals: Descurainia suffruticosa (Coste & Soulié) Aymerich & L. Sáez, Linum suffruticosum subsp. castroviejoi (Mart. Labarga, Pedrol & Muñoz Garm.) L. Sáez & P. Aymerich, Oeosporangium acrosticum (Balb.) L. Sáez & P. Aymerich, Oeosporangium ×kochianus (Rasbach, Reichst. & Schneller) L. Sáez & P. Aymerich i Valeriana tarraconensis (Pau) L. Sáez & Aymerich.En esta aportación se proponen las siguientes combinaciones nomenclaturales: Descurainia suffruticosa (Coste & Soulié) Aymerich & L. Sáez, Linum suffruticosum subsp. castroviejoi (Mart. Labarga, Pedrol & Muñoz Garm.) L. Sáez & P. Aymerich, Oeosporangium acrosticum (Balb.) L. Sáez & P. Aymerich, Oeosporangium ×kochianus (Rasbach, Reichst. & Schneller) L. Sáez & P. Aymerich y Valeriana tarraconensis (Pau) L. Sáez & Aymerich
New nomenclatural combinations in vascular plants
No full textIn this paper the following new nomenclatural combinations are proposed: Descurainia suffruticosa (Coste & Soulié) Aymerich & L. Sáez, Linum suffruticosum subsp. castroviejoi (Mart. Labarga, Pedrol & Muñoz Garm.) L. Sáez & P. Aymerich, Oeosporangium acrosticum (Balb.) L. Sáez & P. Aymerich, Oeosporangium ×kochianus (Rasbach, Reichst. & Schneller) L. Sáez & P. Aymerich and Valeriana tarraconensis (Pau) L. Sáez & Aymerich.En aquesta aportació es proposen les següents noves combinacions nomenclaturals: Descurainia suffruticosa (Coste & Soulié) Aymerich & L. Sáez, Linum suffruticosum subsp. castroviejoi (Mart. Labarga, Pedrol & Muñoz Garm.) L. Sáez & P. Aymerich, Oeosporangium acrosticum (Balb.) L. Sáez & P. Aymerich, Oeosporangium ×kochianus (Rasbach, Reichst. & Schneller) L. Sáez & P. Aymerich i Valeriana tarraconensis (Pau) L. Sáez & Aymerich.En esta aportación se proponen las siguientes combinaciones nomenclaturales: Descurainia suffruticosa (Coste & Soulié) Aymerich & L. Sáez, Linum suffruticosum subsp. castroviejoi (Mart. Labarga, Pedrol & Muñoz Garm.) L. Sáez & P. Aymerich, Oeosporangium acrosticum (Balb.) L. Sáez & P. Aymerich, Oeosporangium ×kochianus (Rasbach, Reichst. & Schneller) L. Sáez & P. Aymerich y Valeriana tarraconensis (Pau) L. Sáez & Aymerich
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
La vita sulle ossa: ricostruzione biologica dell’attività e dello stato di salute delle popolazioni del passato
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