131,267 research outputs found
Fiebre amarilla: a propósito de la alerta
Get PDFResumenLa infección por el virus de la fiebre amarilla es una fiebre hemorrágica aguda inmuneprevenible, potencialmente peligrosa a viajeros no vacunados en áreas enzoóticas, con una elevada mortalidad en los casos sintomáticos. El arbovirus es trasmitido en un ciclo involucrando primates y mosquitos, pero el ser humano puede ser utilizado como huésped intemediario.[Vaga A. Fiebre amarilla: a propósito de la alerta. MedUNAB 2004; 7:15-20].Palabras clave: fiebre amarilla, fiebre viral hemorrágica, enfermedades por arbovirus
MeSH term explosion and author rank improve expert recommendations
Get PDFInformation 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
Phylogenetic diversity of koala retrovirus within a wild koala population
No full textKoala populations are in serious decline across many areas of mainland Australia, with infectious disease a contributing factor. Koala retrovirus (KoRV) is a gammaretrovirus present in most wild koala populations and captive colonies. Five subtypes of KoRV (A to E) have been identified based on amino acid sequence divergence in a hypervariable region of the receptor binding domain of the envelope protein. However, analysis of viral genetic diversity has been conducted primarily on KoRV in captive koalas housed in zoos in Japan, the United States, and Germany. Wild koalas within Australia have not been comparably assessed. Here we report a detailed analysis of KoRV genetic diversity in samples collected from 18 wild koalas from southeast Queensland. By employing deep sequencing we identified 108 novel KoRV envelope sequences and determined their phylogenetic diversity. Genetic diversity in KoRV was abundant and fell into three major groups; two comprised the previously identified subtypes A and B, while the third contained the remaining hypervariable region subtypes (C, D, and E) as well as four hypervariable region subtypes that we newly define here (F, G, H, and I). In addition to the ubiquitous presence of KoRV-A, which may represent an exclusively endogenous variant, subtypes B, D, and F were found to be at high prevalence, while subtypes G, H, and I were present in a smaller number of animal
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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"
Get PDFBoth 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.
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
Haplogonaria amarilla Hooge & Eppinger 2005, sp. nov.
No full textHaplogonaria amarilla sp. nov. (Figs. 1–3) Type Material: Holotype. AMNH PLATY 1658, one set of 1.5µmthick serial sagittal sections of epoxyembedded specimens stained with toluidine blue. Paratypes. AMNH PLATY 1659, one set of 1.5µmthick serial sagittal sections of epoxyembedded specimens stained with toluidine blue, and AMNH PLATY 1660, epoxyembedded whole mount. Type Locality. San Felipe, Baja California, medium grained sand from a small pool of standing sea water at the high intertidal from the south side of San Felipe Bay (30°58'35.1"N, 114°48'22.6"W). Other Material Examined. Living specimens in squeeze preparations; three sets of 1.5µmthick serial sections of epoxyembedded specimens; several whole mounts for fluorescence imaging of musculature. Etymology. Species name is a derivation of the Spanish amarillo, yellow, referring to the species body color. Description. Mature, living specimens up to 650 µm long and 150 µm wide (Figs. 1A, 2). Preserved specimens contracted to approximately 360 µm long and 140 µm wide (Figs. 1B, 3). Body cylindrical. Anterior and posterior ends rounded. Body color yellow by transmitted light. Epidermis completely ciliated. Many large rhabdoid glands present; mostly concentrated at anterior end (Figs. 1, 2). Musculature with circular muscles that encircle the body along entire length of animal; straight longitudinal muscles present between frontal organ and anterior edge of mouth; longitudinalcrossover muscles (fibers with a longitudinal orientation anteriorly, but bend medially to cross diagonally) present in both dorsal and ventral body wall; anterior end with ventral diagonal muscles positioned between outer circular and inner longitudinal muscles (Fig. 3A). Frontal organ well developed; cell bodies of frontal glands positioned ~ 100 µm behind frontal pore (Figs. 1B, 2B). Mouth opening on ventral surface, middle of body. Digestive central syncytium extends from posterior end of frontal glands to level of seminal vesicle. Ovary presumed to be unpaired, ventral; no more than two eggs —positioned medially—discernible in live and sectioned material (Figs. 1, 2A, C). Testes paired, dorsal, compact; separate from ovary. Testes extend anteriorly to level of mouth and posteriorly to male copulatory organ. Common gonopore on ventral surface opens anteriorly to spermfilled seminal vesicle composed of thin layer of muscle and surrounded on ventral and posterior sides by several conspicuous nuclei (Figs. 1B, 2B, 3B). Gonopore opens posteriorly to illdefined, weakwalled vagina that runs anteriorly over dorsal side of seminal vesicle to spermfilled seminal bursa; bursa with welldeveloped bursal wall (Figs. 1B, 2B). Remarks. There are presently 14 described species of Haplogonaria that are united in having an unpaired ovary, paired testes, and a seminal bursa that lacks a bursal nozzle. Some species, such as H. arenaria (Ax, 1959), H. elegans Faubel, 1976, and H. stradbrokensis Hooge, 2003 have a nonmuscular, or weakly muscular seminal vesicle, while other species, such as H. phyllospadicis Hooge & Tyler, 2003, and H. simplex Dörjes, 1968, have a strongly muscular seminal vesicle. H. amarilla is more like the former, with only a very thin layer of muscle contributing to the wall of the seminal vesicle (Fig. 3B). It is unusual for members of the Haploposthiidae to have a vagina positioned as it is in this species; that is, opening posterior to, and passing dorsally over the seminal vesicle. Within the Haplogonaria, this configuration of the vagina is shared only with H. sinubursalia Dörjes, 1968. In other regards, the vagina and bursa of H. amarilla are dissimilar to that of H. sinubursalia, which has a vagina filled with granular secretions (vesicula granulorum), and a bursa bearing a cap of cells on its proximal wall; both of these features are lacking in H. amarilla.Published as part of Hooge, Matthew D. & Eppinger, Neil, 2005, New species of Acoela (Acoelomorpha) from the Gulf of California, pp. 1-14 in Zootaxa 1009 (1) on pages 2-6, DOI: 10.11646/zootaxa.1009.1.1, http://zenodo.org/record/504887
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