130,438 research outputs found
Letheobia erythraea Scortecci
No full textLetheobia erythraea (Scortecci) (Fig 9 C) Eritrean gracile blind-snake Typhlos (sic) erythraeus Scortecci 1928, Atti Soc. Ital. Sci. Nat. Mus. Civ. Stor. Nat. Milano, 67: 291, Fig. 1. Type locality: Saganeiti, Eritrea (15 °04’N, 39 ° 12 ’E, elevation 2200 m), collected by Captain L. Fossati, holotype MSNM 3353 (ex-MSNM 2015). Rhinotyphlops somalicus – (not Boulenger) Roux-Estève 1974: 200 & 1975: 445 (part); Hahn 1980: 35 (part). Rhinotyphlops erythraeus – Largen 1978: 57, 1997: 86; Largen & Rasmussen 1993: 320; McDiarmid et al. 1999: 79; Franzen & Wallach 2002: 181; Wallach & Lanza 2004: 81. Description. Snout obtusely pointed in both dorsal and lateral profiles. Rostral cuneiform, broad below, terminating in a conical point, frontal subtrapezoid; supraoculat transverse, its lateral apex between preocular and ocular; eye invisible; nasal divided, inferior suture arising from second labial; ocular divided into subequal dorsal ocular and ventral subocular; SIP X (N 1, P, S, S); MSR 20, reduction A/B 4–6, B/C 0; MD 443– 462; L/D ratio 68–72; tail without a terminal spine. Brown above and gold below. Size. Largest specimen (NMW 16949 – Gheleb) 245 mm in total length. Habitat. Eritrean montane grassland and woodland. Distribution. Endemic to the Eritrean highlands, 1800–2200 m (Fig. 13). Localities. ERITREA. Gheleb NMW 16949; Saganeiti MSNM 3353 (holotype).Published as part of Wallach, Van, 2007, A review of East and Central African species of Letheobia Cope, revived from the synonymy of Rhinotyphlops Fitzinger, with descriptions of five new species (Serpentes: Typhlopidae), pp. 31-68 in Zootaxa 1515 on page 61, DOI: 10.5281/zenodo.17727
Three-dimensional plume simulation of multi-channel thruster configuration
No full textA three-dimensional hybrid particle-in-cell model of the plume emitted by a four-channel Hall-effect thruster configuration for a preliminary design study has been developed. Results show the presence of a potential well in the central region close to the exit plane of the configuration. Together with the typical characteristics of the single channel ion energy spectrum, a double peak structure in the low energy range is present in the four-channel configuration. It is due to the geometrical effects (four-channel source) and to the anisotropic nature of ion-atom scattering
Measurement of XeI and XeII velocity in the near exit plane of a low-power Hall effect thruster by light induced fluorescence spectroscopy
No full textNear exit plane non-resonant light induced fluorescence spectroscopy is performed in a Hall effect low-power Xenon thruster at discharge voltage of 250~V and anode flow rate of 0.7~mg/sec. Measurement of the axial and radial velocity components are performed, exciting the transition at ~nm in XeI and
the transition at ~nm in XeII. No significant deviation from the thermal velocity is observed for XeI. Two most probable ion velocities are registered at a given position with respect to the thruster axis, which are mainly attributed to different areas of creation of ions inside the acceleration channel.
The spatial resolution of the set-up is limited by the laser beam size (radius of the order of ~mm) and the fluorescence collection optics, which have a view spot diameter of ~mm
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.
Wide-awake anesthesia in Dupuytren's contracture treated with collagenase
No full textThe injection of collagenase followed by cord manipulation is one of the most popular treatments for Dupuytren's contracture. This is traditionally performed under local anesthesia or regional nerve block potentially with sedation. Neither the treatment with collagenase, nor the wide-awake anesthesia are novel techniques for hand surgeons. Nevertheless, we report the first experience of cord manipulation using the wide-awake approach. In this prospective study, we compared the pain perception of patients who underwent wide-awake anesthesia versus traditional local anesthesia. We recorded the pain sensation on a visual analog scale (VAS) (0 to 10) during anesthetic injection, during cord manipulation and before discharge. Wide-awake anesthesia significantly reduced pain levels during anesthetic injection (p = 0.003) and cord manipulation (p = 0.0009). Pain levels did not differ significantly right before discharge in the two groups (p = 0.54). Wide-awake anesthesia can be successfully applied to cord manipulation after collagenase injection in Dupuytren's contracture. This way, it is possible to improve the patient's subjective perspective of the procedure
Il trapianto di fegato
No full textThe significant advances achieved in the last years in the field of liver transplantation have led to an almost routinely performance of this therapeutic approach throughout North America and Western Europe. This has led to an increased demand so that today the real problem is the organ availability and the need to use those supplied only for patients with best chances of success. For this reason timing of the operation and patient selection are of critical importance. The ultimate success depends on better surgical procedures and advances in immunosuppressive therapy, but perhaps even more on an accurate patient evaluation. The patient selection is based on standardized medical criteria which constitute the indication in patients with end-stage liver disease and on a careful search for risk factors. To this purpose the evaluation of the tolerance of the hemodinamic stress during clamping of the inferior vena cava is of critical importance and must be carefully evaluated both in patients with known and unknown coronary disease. Another condition to be considered is lung hypertension which is frequently associated with portal hypertension. Finally, important conditions for a good evaluation are the epatopulmonary syndrome and diabetes. The last condition is not a contraindication unless associated with seve-re vascular, cardiac or renal complications
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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