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Letter to the Nielsen Heirs
Full text linkLetter to the heirs of Mr. and Mrs. Vance A. Nielsen, Dr. and Mrs. Stephen M. Nielsen, and Kristine M. Nielsen; includes a photographhttps://openspaces.unk.edu/kc-letters/1033/thumbnail.jp
Barathronus bruuni Nielsen 1969
No full textBarathronus bruuni Nielsen, 1969 Table 1. Figs. 2, 9 Barathronus bruuni Nielsen, 1969: 51 (type locality: 29°45’S, 64°58’E). Barathronus bruuni: Nielsen et al. 1999: 138. Material examined (1 specimen, SL 39 mm). Holotype: USNM 202104 (SL 39 mm, female), SW Indian Ocean, 29°45’S, 64°58’E, RV Anton Bruun, cr. 6, st. 351 B, Isaacs-Kidd midwater trawl, about 1700 m (sounding 4825 m), 28 June 1964. Diagnosis. Barathronus bruuni differs from the other five Barathronus species with pigmented peritoneum by the following combination of characters: dorsal-fin rays 81, anal-fin rays 73, pectoral-fin rays 25, long rakers on anterior gill arch 33, precaudal vertebrae 36, total vertebrae 86, no ventral flexure of anteriormost vertebrae, 3 fangs on vomer. A distinct brown streak in midline of body and a concentration of brown pigment between dorsal fin and nape. The rounded, 1 mm long otoliths seen through of the skull. Description. Only the holotype is known. For a detailed description see Nielsen (1969: 51). The principal meristic and morphometric characters are shown in Table 1. Comparisons. Barathronus bruuni seems most similar to B. maculatus but differs by having more anal fin rays (73 vs 54–66), more vertebrae (86 vs 74–79) and origin of anal fin below dorsal fin ray no. 10 in B. bruuni and below nos. 15–23 in B. maculatus. Distribution (Fig. 2). Caught pelagically between 1700 m and the surface in the southwestern Indian Ocean.Published as part of Nielsen, Jørgen G., 2019, Revision of the circumglobal genus Barathronus (Ophidiiformes, Bythitidae) with a new species from the eastern North Atlantic Ocean, pp. 231-256 in Zootaxa 4679 (2) on page 239, DOI: 10.11646/zootaxa.4679.2.2, http://zenodo.org/record/377245
The Anosov relation for the Nielsen numbers of maps of infra-nilmanifolds.
Full text linkIn 1985 toonde D. Anosov aan dat voor elke continue afbeelding&nbs p;f:M->M op een nilvariëteit M geldt dat N(f)=|L(f)| . Het Nielsen getal N(f) en het Lefschetz getal L(f) zijn twee aan f geassocieerde getallen die informatie geven over h et aantal vaste punten van f (i.e. x in M: f(x)=x) . Als voor een gegeven f geldt dat deze twee getallen op teken na gelijk zijn, dan zeggen we dat f voldoet aan de Ano sov relatie. In mijn thesis heb ik dit resultaat op twee manieren veralgemeend. Een eerste, voor de hand liggend, manier is om aan te tonen dat d it resultaat ook geldt voor andere klassen van variëteiten. Ik heb dit g edaan voor drie klassen van infra-nilvariëteiten en deze klassen zijn al len gedefinieerd op basis van de geassocieerde holonomiegroep. Ten eerst e toonde ik aan dat elke continue afbeelding van een infra-nilvariëteit met holonomiegroep van oneven orde aan de Anosov relatie voldoet. Hetzel fde resultaat is geldig als we werken met platte, oriënteerbare, veralge meende Hantzsche-Wendt variëteiten. Tot slot toonde ik aan dat de Anosov relatie ook geldt voor continue afbee ldingen op infra-nilvariëteiten met cyclische holonomiegroep, mits een specifieke voorwaarde op de generator van de holono miegroep voldaan is. Een tweede manier om het resultaat van Anosov te veralgemenen, is werken met klassen van afbeeldingen in plaats van alle continue afbeeldingen o p een gegeven variëteit te beschouwen. Deze aanpak gebruikte ik om de An osov diffeomorfismen op infra-nilvariëteiten te onderzoeken en ik stelde vast dat deze eigenschap weinig invloed heeft op de geldigheid va n de Anosov relatie. Echter, voor nergens expanderende afbeeldingen op i nfra-nilvariëteiten toonde ik aan dat de Anosov relatie altijd voldaan i s. Tot slot voor expanderende afbeeldingen f op infra-nilvari ëteiten M leidde ik het volgende: f vold oet aan de Anosov relatie als en slechts als M oriënteer baar is. In een laatste deel onderzocht ik wat deze resultaten ons zeggen met bet rekking tot de Anosov relatie voor afbeeldingen op infra-nilvariëteiten met als dimensie hoogstens 4. Zo toonde ik aan dat reeds veel infra-nilv ariëteiten behandeld worden door onze resultaten en ontdekte ik enkele o nderzoeksvragen voor de toekomst.
Neobythites monocellatus Nielsen 1999
No full textNeobythites monocellatus Nielsen 1999 (Fig. 3N) Material examined. MOVI 39139 (1, 97 mm SL), E-0500. Diagnosis. No preopercular spine; dorsal fin with 1 ocellus, none on anal fin. Distribution. Western Atlantic from off Honduras to off Bahia, at depths from 115 to 440 m. Remarks. First record in Brazilian waters. Collected from a single station off Bahia, from 360 to 433 m. The 97 mm specimen falls within the variation of all the characters listed by Nielsen (1999, Table 5) which was based on the examination of 71 specimens.Published as part of Mincarone, Michael M., Nielsen, Jørgen G., Costa, Paulo A. S. & Rv, Rv, 2008, Deep-sea ophidiiform fishes collected on the Brazilian continental slope, between 11 ° and 23 ° S, pp. 41-64 in Zootaxa 1770 (1) on page 53, DOI: 10.11646/zootaxa.1770.1.2, http://zenodo.org/record/512395
Neobythites australiensis Nielsen 2002
No full textNeobythites australiensis Nielsen, 2002 Figure 1, Tables 1, 2 Neobythites australiensis Nielsen, 2002: 20, fig. 10 (Southwest of Rowley Shoals, 18°4.6′S, 118°22′E, Western Australia, 327– 328 m; holotype: WAM P.28107-001). Diagnosis. Hind margin of preopercle with two spines; dorsal-fin rays 88–92; anal-fin rays 73–77; pectoral-fin rays 26–27; precaudal vertebrae 13; total vertebrae 53–54; pseudobranchial filaments 8–11; long rakers on anterior gill arch 9–10; head length 23–25% SL; pelvic-fin length 14–19% SL, fins not reaching anus; orbit length 4.2–4.7% SL and 17–19% HL; longest gill filament 1.6–1.8% SL and 6.7–7.4% HL; dorsal fin with large ocellus placed slightly behind line through anus, spot distance 44–49% SL and spot covers 9–13 dorsal-fin rays, not extending ventrally onto body; preserved specimens with dark-brown ocellus spot; no vertical bars on body; otolith length 5.8–5.9% SL, sulcus length 4.7–4.8% SL, and ostium height 13–14% sulcus length and 19–20% ostium length. Distribution and size. SE Indian Ocean, off NW Australia at 42–350 m depth. Known up to 245 mm SL.Published as part of Uiblein, Franz & Nielsen, Jørgen G., 2023, Five new ocellus-bearing species of the cusk-eel genus Neobythites (Ophidiidae, Ophidiiformes) from the West Pacific, with establishment of three new species groups, pp. 179-205 in Zootaxa 5336 (2) on page 187, DOI: 10.11646/zootaxa.5336.2.2, http://zenodo.org/record/827241
Neobythites monocellatus Nielsen 1999
No full textNeobythites monocellatus Nielsen 1999 (Figs. 1, 4– 5) Neobythites monocellatus Nielsen 1999: 351, fig. 8 (type locality off Venezuela, 9 ° 53 ’N, 59 ° 53 ’W). Neobythites monocellatus: Mincarone et al. 2008: 53, fig. 3 N. Material examined. 71 specimens, SL 36–154 mm. Holotype and 69 paratypes: for catalog numbers and localities see Nielsen (1999: 351). Additional material: MOVI 39139, unripe, 97 mm SL, 13 ° 22.057 ’S, 38 ° 40.204 'W – 13 ° 19.472 ’S, 38 ° 38.035 ’W, RV THALASSA, st. E 500, bottom trawl, 360–433 m, 8 Jun. 2000. Diagnosis. Neobythites monocellatus differs from all other Atlantic Neobythites species by having only one ocellus on the dorsal fin, placed anteriorly to the midpoint of the fish (snout to ocellus-spot 41.0–51.0 % SL) and by the following combination of characters: preopercle lacking a distinct spine on the posterior edge (rather developed as a flat, broad process), dorsal fin rays 93–99, anal fin rays 78–83, and total vertebrae 54– 58. Similarity. Judging from the number of ocelli on the dorsal fin (Table 3) N. monocellatus is closest to N. gilli and N. ocellatus which both have two distinct ocelli. In meristic characters N. monocellatus is closest to N. multiocellatus and N. ocellatus. Description. Table 1 shows a comparison between the Brazilian specimen and the type material (70 specimens). In spite of the large geographical separation between the type material and the new Brazilian specimen the latter falls within the variation of all characters. For comparison reasons the sagittal otolith is shown on Figure 5. See Nielsen (1999: 351) for a detailed description. Distribution. Neobythites monocellatus is found from Honduras and along the north coast of South America to French Guiana and now also off Bahia, Brazil (13 °S), an extension of ca. 3000 km (Fig. 1). Caught on the continental shelf and upper slope, at depths from 117 to 439 m.Published as part of Nielsen, Jørgen G., Uiblein, Franz & Mincarone, Michael M., 2009, Ocellus-bearing Neobythites species (Teleostei: Ophidiidae) from the West Atlantic with description of a new species, pp. 57-68 in Zootaxa 2228 on pages 62-63, DOI: 10.5281/zenodo.19024
Neobythites malhaensis Nielsen 1995
No full textNeobythites malhaensis Nielsen, 1995 (Figures 1–2, Tables 1, 3) Neobythites malhaensis Nielsen, 1995: 6, fig. 5a. Holotype. ZM MGU P-18915 (male, 123 mm SL), Saya de Malha Bank, Western Indian Ocean, 11°02' S, 62°15' E, 250 m depth (probably same cruise as paratypes). Paratypes (n = 3; 117–135 mm SL). Saya de Malha Bank, Western Indian Ocean: ZM MGU P-18916 (female, 117 mm SL), 11°08' S, 62°16' E, RV Professor Mesiatzev, trawl 476, 235 – 239 m depth, 7 Oct 1977; ZM MGU P- 18917 (female, 132 mm SL), 11°06' S, 62°19' E, RV Professor Mesiatzev, trawl 478, 240 m depth, 7 Oct 1977; ZMUC P77840 (female, 135 mm SL), RV Fiolent, 1973 (no other data). Diagnosis. Indistinct or flat spine on hind margin of preopercle; dorsal fin-rays 99–103; anal-fin rays 78–82; pectoral fin-rays 30; precaudal vertebrae 13; total vertebrae 57–59; pseudobranchial filaments 3–4; long gill rakers on anterior arch 12–13; head length 21.0–21.5 % SL; pelvic-fin length 12.5–13.0 % SL, pelvic fins not reaching anus; orbit length 4.1–4.9 % SL, 19.5–23.0 % head length, and 2.2–2.4 times in upper-jaw length; longest gill filament 1.6–1.9 % SL and 7.5–8.9 % head length; ocellus spot placed behind a vertical line through anus, the ocellus-spot distance being 42.5–45.5 % SL, and the spot covering 13 dorsal-fin rays; dorsal and anal fins not pigmented; one vertical, dark bar on body below ocellus spot; otolith length 5.2 % SL, sulcus length 3.8 % SL, and ostium height 21.5 % sulcus length. Distribution. Saya de Malha Bank, off SE Seychelles, Western Indian Ocean, at 235–250 m depth.Published as part of Uiblein, Franz & Nielsen, Jørgen G., 2018, Review of the steatiticus - species group of the cuskeel genus Neobythites (Ophidiidae) from the Indo-Pacific, with description of two new species, pp. 157-173 in Zootaxa 4387 (1) on pages 164-165, DOI: 10.11646/zootaxa.4387.1.7, http://zenodo.org/record/118673
Letter, 1949 March 25, from J. M. Nielsen to Carson Robison
Full text link1 page, Nielsen is the Manager of the MGM Record Division for Zenith Radio Distributing Corp. A Natt is no longer with the the corporation. Randy Blake, a folk radio host, is meantioned in the letter
Two, more readily computable equivariant Nielsen numbers I. Nielsen theory for M-ads
No full textAbstractIn this, the first of two papers outlining a Nielsen theory for “two, more readily computable equivariant numbers”, we define and study two Nielsen type numbers N(f,k;X−{Xν}ν∈M) and N(f,k;X,{Xν}ν∈M), where f and k are M-ad maps. While a Nielsen theory of M-ads is of interest in its own right, our main motivation lies in the fact that maps of M-ads accurately mirror one of two fundamental structures of equivariant maps. Being simpler however, M-ad Nielsen numbers are easier to study and to compute than equivariant Nielsen numbers. In the sequel, we show our M-ad numbers can be used to form both upper and lower bounds on their equivariant counterparts.The numbers N(f,k;X−{Xν}ν∈M) and N(f,k;X,{Xν}ν∈M), generalize the generalizations to coincidences, of Zhao's Nielsen number on the complement N(f;X−A), respectively Schirmer's relative Nielsen number N(f;X,A). Our generalizations are from the category of pairs, to the category of M-ads. The new numbers are lower bounds for the number of coincidence points of all maps f′ and k′ which are homotopic as maps of M-ads to f, respectively k firstly on the complement of the union of the subspaces Xν in the domain M-ad X, and secondly on all of X. The second number is shown to be greater than or equal to a sum of the first of our numbers. Conditions are given which allow for both equality, and Möbius inversion. Finally we show that the fixed point case of our second number generalizes Schirmer's triad Nielsen number N(f;X1∪X2).Our work is very different from what at first sight appears to be similar partial results due to P. Wong. The differences, while in some sense subtle in terms of definition, are profound in terms of commutability. In order to work in a variety of both fixed point and coincidence points contexts, we introduce in this first paper and extend in the second, the concept of an essentiality on a topological category. This allows us to give computational theorems within this diversity. Finally we include an introduction to both papers here
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