1,722,016 research outputs found
Spilomena elephantodeta Simon Thomas 1995
No full textSpilomena elephantodeta Simon Thomas, 1995 Distribution in the Arabian Peninsula: Yemen (Simon Thomas 1995). Extralimital distribution: No records.Published as part of Gadallah, Neveen S., 2020, Biodiversity of the aculeate wasps (Hymenoptera: Aculeata) of the Arabian Peninsula: Apoidea (Spheciformes), Crabronidae, pp. 20-73 in Zootaxa 4754 (1) on pages 20-73, DOI: 10.11646/zootaxa.4754.1.6, http://zenodo.org/record/371905
Spilomena nigrifrons Simon Thomas 1995
No full text<i>Spilomena nigrifrons</i> Simon Thomas, 1995 <p>Distribution in the Arabian Peninsula: Yemen (Simon Thomas 1995).</p> <p>Extralimital distribution: No records.</p>Published as part of <i>Gadallah, Neveen S., 2020, Biodiversity of the aculeate wasps (Hymenoptera: Aculeata) of the Arabian Peninsula: Apoidea (Spheciformes), Crabronidae, pp. 20-73 in Zootaxa 4754 (1)</i> on pages 20-73, DOI: 10.11646/zootaxa.4754.1.6, <a href="http://zenodo.org/record/3719051">http://zenodo.org/record/3719051</a>
Miscophus pseudochrysis Simon THOMAS 1995
No full text<i>Miscophus pseudochrysis</i> Simon THOMAS, 1995(figs 15-17) <p> <i>Miscophus pseudochrysis</i> SIMON THOMAS, 1995: 129, ♁, ♀. Holotype: 1♀, Senegal: 25-35 km S Richard Toll (LUW), examined.</p> <p>M a t e r i a l e x a m i n e d: SENEGAL: 1♀ 1♁, 13.ix./ 27.ix.1989 25-35 km S Richard Toll, in malaise traps [♀ Holotype, ♁ paratype] (RMNH); 1♀ 25.xii.1986 Mdzugan (CAS); 1♀ 20.ii.1988 F. Borgale (CAS). ISRAEL. 5♁♁ 5♀♀ 8.v.1996 Arava Valley, Iddan, 30.807N 35.298E; 1♀ 8.v.1996 45km SE Beer Sheva, Mezad Aqrabbim, 3♁♁ 16.vi.1995 Hazeva. (leg. M. Irvin in Malaise traps, CSE).</p> <p>D i s t r i b u t i o n: Israel, Senegal.</p>Published as part of <i>Schmid, Christian, Al, Ali & J, A -, 2022, The genus Miscophus JURINE, 1807 in Arabian Peninsula and southern Israel with description of seven new species (Hymenoptera, Spheciformes), pp. 319-340 in Linzer biologische Beiträge 54 (1)</i> on page 331, DOI: <a href="http://zenodo.org/record/7507544">10.5281/zenodo.7507544</a>
On the Heliospheric Modulation of Galactic Cosmic Rays - Thesis
No full textThesis of Dr. Simon Thomas of the University of Reading
A tool that may help to tackle atrial fibrillation
No full text Untreated atrial fibrillation can increase the risk of stroke by up to six times, but its management presents a considerable resource challenge. A joint working group has created an online tool to help practitioners and patients, Simon Thomas explains </jats:p
Vortrag von Mienke Simon Thomas und Christiane Heiser: Niederländisch-deutsche Wurzeln des Bauhauses. Die Rolle von Rheinland und Westfalen
No full textMienke Simon Thomas vom Museum Boijmans Van Beuningen in Rotterdam und die Kunsthistorikerin Christiane Heiser teilen sich ihren Vortrag. Thomas beginnt mit der Darstellung der Konzeption einer Ausstellung über Bauhaus, die bald in Rotterdam anlaufen wird. Christiane Heiser fährt mit Beispielen für niederländischen Einfluss auf das Bauhaus und seine Vertreter fort. Wie kann man das Bauhaus in einer europäisch ausgerichteten Ausstellung gebührend darstellen? Mienke Simon Thomas stellt mit dem ..
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
Synthetic approaches to proposed biosynthetic intermediates of the polyther ionophore monensin
No full textThis thesis describes progress towards the synthesis of putative biosynthetic precursors of monensin B. It also contains a synthetic investigation into the hypothetical polyepoxide cyclisations proposed in the biosynthesis. The synthesis of (5E, 9E, HS)-13-benzyloxy-5,9-11-trimethyltrideca-5,9-dien-2-yl triethylsilylether (24) is described. Using a stereoselective alkylation process, (2'S, 4R 5S)-(+)-4-methyl-3-(2'-methyl-1'-oxopent-4'-enyl)-5-phenyl-2-oxazolidone (33) was prepared, containing the required chiral centre. This strategy, however, was not found to be viable at multigram scales. An alternative method utilised R-(+)-pulegone (27) as a chiral precursor to the key synthetic intermediate (2S)-4-benzyloxy-2-methylbutan-1-al (25). Conversion to (4S)-6-benzyloxy-2,4-dimethylhex-1-en-3-ol (49), followed by a ketal Claisen rearrangement produced (6E, 8S)-(+)-10-benzyloxy-2,6,8-trimethyldeca-1,6-dien-3-one (58) containing one of the two required (E)-trisubstituted double bonds. The second double bond was constructed using an orthoester Claisen rearrangement on (6E, 8S)-10-benzyloxy-2,6,8-trimethyldeca-1,6-dien-3-ol (50) which gave (4E, 8E, 10S)-(+)-ethyl-12-benzyloxy-4,8,10-trimethyldodeca-4,8-dienoate (77). This was converted into the required silyl ether (24), which is a useful intermediate in the synthesis of a proposed triene precursor (140) monensin B. The preparation of two fragments of monensin B with appropriate relative and absolute stereochemistry, namely, (+)-(5S)-5-[(2S, 5R, 1'R)-2-(1',2'-dihydroxyethyl)-2-methyltetrahydrofuran-5-yl]-5-methyldihydrofuran-2-one (194), and (-)-(5S)-5-[(2S, 5R, 5'R)-2-(dihydrofuran-2'-one-5'-yl)-2-methyltetrahydrofuran-5-yl]-5-methyldihydrofuran-2-one (200), is described. This involved the use of an unusual polyepoxide cyclisation procedure which has been implicated in the biosynthesis of monensin. (4R, 5R, 8R, 9R)-(+)-Methyl-4,5-8,9-diepoxy-4,8-dimethyl-10-hydroxydecanoate (166) was prepared from geraniol (72) using Sharpless asymmetric epoxidations as the key steps. Incubation with pig liver esterase gave the bicyclic lactone (194). Similarly (4R, 5R, 8R, 9R)-(+)-methyl-4,5-8,9-diepoxy-4,8-dimethyl-11-formylundecanoate (169) was prepared from the diepoxide (166) and underwent cyclisation with pig liver esterase to give (5S)-5-[(2S, 5R, 5'R)-2-(tetrahydrofuran-2'-ol-5'-yl)-2-methyltetrahydrofuran-5-yl]-5-methyldihydrofuran-2-one (197). This was converted into the tricyclic dilactone (200) and the assigned relative stereochemistry confirmed by a single crystal X-ray diffraction analysis. An n.m.r. study of the cyclisation of (166) into (194) revealed that a monocyclic intermediate (201) was involved in the process. These results enhance the relevance of polyepoxide cyclisations to polyether biosynthesis and present new methodology for polyether synthesis. (D82124)</p
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