136,745 research outputs found
Optimization of transcoding on multi-core processors
No full textHofman, D. (2013). Optimization of transcoding on multi-core processors. https://riunet.upv.es/handle/10251/27594.Archivo delegad
Linear equations for unordered data vectors in
No full textFollowing a recently considered generalisation of linear equations to
unordered-data vectors and to ordered-data vectors, we perform a further
generalisation to data vectors that are functions from k-element subsets of the
unordered-data set to vectors of integer numbers. These generalised equations
naturally appear in the analysis of vector addition systems (or Petri nets)
extended so that each token carries a set of unordered data. We show that
nonnegative-integer solvability of linear equations is in nondeterministic
exponential time while integer solvability is in polynomial time
Litthabitellidae Falniowski and Hofman 2023, fam. nov.
No full textFamily LITTHABITELLIDAE Falniowski and Hofman, fam. nov. urn:lsid:zoobank.org:act: A8E1F6A7-EEAE-4B8D-A82D-19A7144283C6 Type genus Litthabitella Boeters, 1970 Diagnosis Minute truncatelloid snails with the following synapomorphic character states: osphradium broadly ovate; pallial oviduct gland complex short; gonoporus deep inside the mantle cavity; the ventral channel not on the ventral side of the capsule gland, but somewhat lateral; thickened oviduct circular; the distal termination of the penis wide and blunt, with sharp and short filament harbouring the vas deferens situated laterally, and with two flat, cockscomb-like, four-folded lobes. Description Shell (Figures 3 and 4) ovate conical, convex in outline, thick-walled; the border between the proto- and teleoconch is easily discernible, the initial part of the protoconch narrow, on the protoconch surface only delicate irregularities (Figure 5 (a–c)), aperture pyriform, teleoconch smooth with delicate growth lines. Operculum (Figure 6) thin and horny, colourless and translucent, elongate-ellipsoidal, spiral, paucispiral, with submarginal nucleus. Head and tentacles white, with no pigment, no hyperciliation (long and dense cilia at one or two cephalic tentacles, characteristic of e.g. some Hydrobiidae); mantle partly black pigmented. Osphradium (Figure 7 (a)) broadly ovate; ctenidium well developed. In the radula (Figures 5 (d–i) and 8(b)) the central tooth with deep sinus at the proximal part of the cutting plate and one pair of large and prominent basal cusps. The median cusp narrow and slender, more than twice as long as the adjacent cusps, similar in shape. On each side of the median cusp are four to five cusps; the cutting edge is straight, with no cusps. In the lateral tooth, the biggest cusp is triangular, twice as long and broad as the adjacent ones. The formula of the tooth is (5)4–1–5; on the inner marginal tooth 26–28 long and slender cusps. The caecum is absent (Figure 8 (c)). The pallial oviduct gland complex (Figure 7 (a)) is relatively short, lying far posteriorly of the mantle margin, thus the gonopore is at the terminal part of the capsule gland and situated deep inside the mantle cavity, far behind the anus. The ventral channel is not on the ventral side of the capsule gland, but lies somewhat laterally (Figure 7 (b,d)). There is a bursa copulatrix and two receptacula typical of the Truncatelloidea: a distal one (rs 1 after Radoman 1983) situated near the junction of the oviduct and the duct of the bursa, and a proximal one (rs 2 after Radoman 1983) situated at the proximal end of thickened oviduct; in Litthabitella the proximal receptaculum is vestigial. The thickened oviduct is circular, forming neither a spiral nor a horseshoe-like loop (Figure 7 (c)). The prostate is small, nearly vestigial, observable as slight outgrowth of the vas deferens. The penis is big and massive (Figures 9 and 10), filled with glandular tissue (Figure 10), with a distal termination that is wide and blunt, with a sharp and short filament harbouring the vas deferens, which is situated laterally, and two flat, cockscomb-like, four-folded lobes. Molecular phylogeny We obtained 26 new sequences of COI (457 bp, GenBank accession numbers ON661272–ON661297), 16 of H3 (310 bp, GenBank accession numbers ON661565– ON661580) and 24 of 18S (401 bp, GenBank accession numbers ON667998– ON668023). The tests by Xia et al. (2003) revealed no saturation. Results from the substitution saturation analysis showed an Index of substitution saturation (ISS) (0.71 for COI; 0.48 for H3) significantly smaller than the critical ISS value (ISSC: 0.97 for COI; 0.59 for H3), indicating that all sequences are useful in phylogenetic reconstruction. In all analyses, the topologies of the resulting phylograms were identical in the ML and BI phylogram analyses; thus, we present the phylogram computed with RAxML. The COI phylogram (Figure 11) clearly shows all the populations of Litthabitella as a distinct, highly supported group (bootstrap 99%). As usual with COI, deeper nodes are not well supported; thus, the relationships among the Litthabitella remain unresolved. In the 18S phylogram of Szarowska (2006), Emmericia was a sister clade to all the Hydrobiidae (including Hydrobiinae and Sadlerianinae sensu Szarowska 2006). The time of divergence of the Litthabitellidae was estimated as 8.69 ± 1.87 Mya in the COI phylogram. Our 18S phylogram (Figure 12) shows a similar picture: a well-supported clade (bootstrap 83%) includes all the Hydrobiidae and Litthabitella, with the latter as the sister clade of all the Hydrobiidae. The set of available sequences of histone H3 was very restricted, but the relationships (Figure 13) are similar to those in the 18S phylogram; the well-supported clade (bootstrap 97%) includes Litthabitella as a sister clade of all the Hydrobiidae, but also of Heleobia (Cochliopidae). The phylogram inferred for the three concatenated loci (Figure 14) also shows the Litthabitellidae as a sister taxon to all the Hydrobiidae, but the clade joining the Litthabitellidae and Hydrobiidae is not well supported (only 62%); the clade Litthabitellidae is well supported (bootstrap 100%).Published as part of Falniowski, Andrzej, Jaszczyńska, Aleksandra, Osikowski, Artur & Hofman, Sebastian, 2023, Litthabitellidae: a new family of the Truncatelloidea (Mollusca: Caenogastropoda), pp. 299-329 in Journal of Natural History 57 (5 - 8) on pages 305-307, DOI: 10.1080/00222933.2023.2168573, http://zenodo.org/record/777820
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.
- …
