186,429 research outputs found
Dorylaimus conicaudatus Ditlevsen 1927, n. sp.
No full textDorylaimus conicaudatus n. sp. <p>Locality: Kapisigdlit. The Fjord of Godthaab. 9. 7. - 24. 8. 1926. Reisinger and Steinböck.</p> <p> Female: Length 2,0 mm. <b>α</b> =30; <i>ß</i> = 6,1; y = 30.</p> <p>Vulva 41,7 %.</p> <p>This very nice form is present in several specimens, some of which are fullgrown females, while the rest comprises young individuals. No male was seen.</p> <p> This species is beyond doubt nearly related to the subgenus Doryllium. It has a straight, rather long and relatively slender spear, and this is continued by a pseudo-spear much like that known in STEıNr-:ıüs <i>D</i>. <i>macrodoraides</i>, but it is easily distinguished from this form, by means of the relatively short oesophagus and the shape of the tail.</p> <p> The front end narrows quickly, and in this respect it is very much like <i>D</i>. <i>groenlandicus</i>. The head is rounded and neither lips nor papillae are obvioufl (fig. 15).</p> <p>The foremost half of the oesophagus is thin, and at the end of this the nerve ring is found; it is hardly observable, and behind it the oesophagus increases towards its base. Immediately caudad to the nerve ring a pear-shaped, rather lengthened, body is observed (fig. 18). It is situated at the ventral side of the oesophagus and is much like the ventral gland, known in most of the marine species of freeliving Nematodes. It was observed in nearly all the specimens at hand, but unfortunately I was not able to observe where it opens; I am most inclined to mean that it must be into the oesophagus itself and not at the surface of the body. The ante-rectum is relatively long and makes almost the half of the length of the oesophagus.</p> <p>As to the shape of the tail, I shall remark that in most of the specimens it is conical with rounded tip as shows the fig. 16; but in some few it is somewhat more acute as in fig. 17, only the tip is never pointed. The female pore is situated somewhat cephalad to the middle of the body. The ovaries are rather short and symmetrical. Though several full-grown females are present, not a single was seen with shell-eggs in the uterus.</p>Published as part of <i>Ditlevsen, Hjalmar, 1927, XXII. Free-living Nematodes from Greenland, Land and Freshwater., pp. 175-189 in Meddelelser om Gronland 22</i> on pages 179-180, DOI: <a href="http://zenodo.org/record/10834709">10.5281/zenodo.10834709</a>
Dorylaimus faroensis Ditlevsen 1928
No full text<p> <i>Dorylaimus faroensis</i> Ditlevsen, 1928</p> <p> becomes: <i>Dorylaimellus faroensis</i> (Ditlevsen, 1928) n. comb.</p>Published as part of <i>Thorne, Gerald & Swanger, Helen Heinly, 1936, A Monograph Of The Nematode Genera Dorylaimus Dujardin, Aporcelaimus N. G., Dorylaimoides N. G. And Pungentus N. G., pp. 139-150 in Capita Zoologica VI (4)</i> on page 142, DOI: <a href="http://zenodo.org/record/10845898">10.5281/zenodo.10845898</a>
Dorylaimus (Doryllium) analatus Ditlevsen 1927
No full text<p> <i>Dorylaimus</i> (<i>Doryllium</i>) <i>analatus</i> Ditlevsen, 1927</p> <p> becomes: <i>Dorylaimellus analatus</i> (Ditlevsen, 1927) n. comb.</p>Published as part of <i>Thorne, Gerald & Swanger, Helen Heinly, 1936, A Monograph Of The Nematode Genera Dorylaimus Dujardin, Aporcelaimus N. G., Dorylaimoides N. G. And Pungentus N. G., pp. 139-150 in Capita Zoologica VI (4)</i> on page 142, DOI: <a href="http://zenodo.org/record/10845898">10.5281/zenodo.10845898</a>
Dorylaimus (Doryllium) groenlandicus Ditlevsen 1927
No full text<p> <i>Dorylaimus</i> (<i>Doryllium</i>) <i>groenlandicus</i> Ditlevsen, 1927</p> <p> becomes; <i>Dorylaimellus groenlandicus</i> (Ditlevsen, 1927) n. comb.</p>Published as part of <i>Thorne, Gerald & Swanger, Helen Heinly, 1936, A Monograph Of The Nematode Genera Dorylaimus Dujardin, Aporcelaimus N. G., Dorylaimoides N. G. And Pungentus N. G., pp. 139-150 in Capita Zoologica VI (4)</i> on page 142, DOI: <a href="http://zenodo.org/record/10845898">10.5281/zenodo.10845898</a>
Parasphaerolaimus Ditlevsen 1918
No full textGenus <i>Parasphaerolaimus</i> Ditlevsen, 1918 <p> <b>Diagnosis</b> (modified from Fonseca & Bezerra 2014). Sphaerolaimidae. Buccal cavity has six anterior and three posterior, circularly arranged elements. The anterior-most part of the inner pharyngeal wall transformed into six plates. Longitudinal ribs of the lip region in all juvenile stages correspond to a uniform pattern that differs from that of the adults. Eight groups of subcephalic setae present in all juvenile stages and adults.</p> <p> <b>Type species</b>: <i>Parasphaerolaimus paradoxus</i> Ditlevsen, 1918</p> <p> = <i>Sphaerolaimus paradoxus</i> (Ditlevsen, 1918) Filipjev, 1946</p>Published as part of <i>Cai, Lizhe, 2017, Two new ovoviviparous species of the family Selachinematidae and Sphaerolaimidae (Nematoda, Chromadorida & Monhysterida) from the northern South China Sea, pp. 95-110 in Zootaxa 4317 (1)</i> on page 101, DOI: 10.11646/zootaxa.4317.1.4, <a href="http://zenodo.org/record/880136">http://zenodo.org/record/880136</a>
Dorylaimopsis Ditlevsen 1918
No full textGenus <i>Dorylaimopsis</i> Ditlevsen, 1918 Diagnosis (modified from Jensen (1979)) <p>Dorylaimopsinae. Cuticle with lateral differentiation consisting of longitudinal rows of coarse dots; posterior portion of buccal cavity cylindrical, with three thorn-like teeth at border to anterior portion; outer labial sensillae and cephalic setae in separate circles; spicules usually long, arcuate or jointed; caudal or dorso-caudal gubernacular apophyses.</p> Type species <p> <i>Dorylaimopsis punctata</i> Ditlevsen, 1918</p>Published as part of <i>Leduc, Daniel, 2012, Deep-sea nematodes (Comesomatidae) from the Southwest Pacific Ocean: five new species and three new species records, pp. 1-42 in European Journal of Taxonomy 24</i> on page 19, DOI: 10.5852/ejt.2012.24, <a href="http://zenodo.org/record/3858345">http://zenodo.org/record/3858345</a>
Parasphaerolaimus Ditlevsen 1919
No full textDiagnosis of <i>Parasphaerolaimus</i> Ditlevsen, 1919 (after Fonseca & Bezerra, 2014 and Zograf <i>et al</i>. 2017). <p> Sphaerolaimidae. Cuticle striated or annulated. Six outer labial setiform sensilla and four cephalic setiform sensilla in one circle, with cephalic ones longer than labial ones. Eight groups of subcephalic setae corresponding to those of the Sphaerolaiminae occur in all four juvenile stages as well as in the adults. Stoma wide, barrel-shaped; only at basis surrounded by pharyngeal tissue. Inner wall of pharynx with thick cuticle. Wall of the buccal cavity consisting of six anterior and three posterior, circularly arranged elements. The anterior-most part of the inner pharyngeal wall transformed into six plates. Sexual dimorphism in size of amphids. Ventral gland present, opening behind nerve ring. Males usually with two testes, anterior one either on the left or on the right side of intestine, posterior one on the opposite side. Females with one (anterior) ovary on the left or right side of intestine. Type species: <i>P. paradoxus</i> Ditlevsen, 1919</p>Published as part of <i>Cavalcanti, Mariana Da Fonseca & Venekey, Virag, 2017, Parasphaerolaimus magdolnae sp. n. (Nematoda, Sphaerolaimidae) with intra-uterine development of its offspring from a Brazilian estuarine system, pp. 339-350 in Zootaxa 4358 (2)</i> on page 340, DOI: 10.11646/zootaxa.4358.2.7, <a href="http://zenodo.org/record/1068099">http://zenodo.org/record/1068099</a>
Thoracostomopsis Ditlevsen 1918
No full textGenus <i>Thoracostomopsis</i> Ditlevsen, 1918 <p> Ditlevsen (1918) established a new genus for an organism collected in Little Belt, Denmark, <i>Thoracostomopis barbata</i> Ditlevsen, 1918 based on a single female.Although, this genus is very similar to <i>Thoracostoma</i>, which have the tail constricted before the tip, it differs by having the head covered with a cephalic capsule much narrower than the adjacent part of the body; the buccal cavity is provided with a thin, acute spear to the proximal end of which the chitin-intima of the pharynx is attached. Filipjev (1927) described three species for the genus: <i>Thoracostomopsis ditlevseni</i> Filipjev, 1927, which was later transferred to <i>Metaphanoderma ditlevseni</i> (Filipjeb, 1927) Platonova, 1984b; <i>Thoracostomopsis galeata</i> Filipjev, 1927 with description of only female, showing a strong cephalic capsule; and <i>Thoracostomopsis longissima</i> Filipjev, 1927 bearing small spicules. Subsequently, <i>Thoracostomopsis carolae</i> Inglis, 1964 were described and <i>T. barbata</i> was invalidated because its description was based on an immature female and a true spear in the buccal cavity of were not be evidenced (Inglis, 1964). Nevertheless, a male of <i>T. barbata</i> was described by Allgén (1935) and subsequently a detailed description of this species was provided by Blome (1982). <i>Thoracostomopsis doveae</i> Warwick, 1970c was the most recent species described for this genus and it is distinguished from other species by long spicules, presence of gubernaculum, cephalic capsule bearing uniformly rounded lobes, different mandible structure and larger overall size.</p> <p> <b>Diagnosis</b> from Smol <i>et al.</i> (2014): Mandibles are reduced and three onchia are elongated and wrapped around each other to form an axial spear-like structure. The cephalic capsule is strongly lobed and the incisions are very broad. The spicules can be long and slender or short and stout with or without a gubernaculum. The cephalic setae vary in length. Tubular precloacal supplement usually present. Marine.</p> <p> <b>Number of valid species:</b> 4</p> <p> <b>1.</b> <i>Thoracostomopsis barbata</i> Ditlevsen, 1918 (Danish Belt Sea) new status— type species <b>2.</b> <i>Thoracostomopsis carolae</i> Inglis, 1964 (South Africa)</p> <p> <b>3.</b> <i>Thoracostomopsis doveae</i> Warwick, 1970c (North Sea)</p> <p> <b>4.</b> <i>Thoracostomopsis longissima</i> Filipjev, 1927 (Barents Sea)</p> <p>SPECIES INQUIRENDA</p> <p> <b>1.</b> <i>Thoracostomopsis galeata</i> Filipjev, 1927 (Barents Sea)</p>Published as part of <i>De Souza, João V. & Maria, Tatiana F., 2023, Taxonomic review of Thoracostomopsidae (Nematoda, Enoplida): state of the art, list of valid species and dichotomous keys, pp. 463-496 in Zootaxa 5361 (4)</i> on pages 487-488, DOI: 10.11646/zootaxa.5361.4.2, <a href="http://zenodo.org/record/10152589">http://zenodo.org/record/10152589</a>
Mononchus dolichurus Ditlevsen.
No full text<i>Mononchus</i> <i>dolichurus</i> Ditlevsen. <p>1911. H. Ditlevsen, Danish freeliving Nematodes. Vid. Medd. Nath. Foren. Kobenhavn Bd. 63. p. 228-229. PI. II. figs. 6, 10, 11.</p> <p> Von dieser interessanten Art waren bis jetzt zwei unreife Weibchen bekannt, welche Ditlevsen (l. c.) in Jütland nahe am Meer fand. Bevor ich die Arbeit von Ditlevsen kannte, lagen mir 60 zum größten Teil reife Weibchen vor, und ich vermutete, daß es sich um eine neue Art handle. Mein Material stammt aus einer Wiese im Avers (Kt. Graubünden) bei einer Höhe von 2140 — 2160 m. So ist es mir nun möglich, die naturgemäß nicht ganz vollständige Beschreibung Ditlevsens zu ergänzen. Auf den Schwanz paßt sie sozusagen wörtlich: "The tail, after which I have named the animal, is longer than in any species of this genus hitherto known; it measures but 4 1/2 in the length of the animal. It is kept bent inwards towards the vent forming a regular circular arch." Auch in bezug auf die de Mansche Formel ist die Übereinstimmung eine bemerkenswerte. Ditlevsen gibt für sein etwa 4 mm langes Exemplar an: α = 41, = γ = 4 1 <i>β</i> 4, /2. Bei fünf von mir gemessenen Individuen liegen die Verhältnisse folgendermaßen:</p> <p> 1) α = 34, β = /2, 4 1 γ = 5 (Länge 4,10 mm. Geschlechtsorgane noch nicht entwickelt).</p> <p> 2) <i>α</i> = 31, β = 4 , γ = 5 (Länge 5,10 mm. Geschlechtsorgane vorhanden).</p> <p> 3) <i>α</i> = 35, β = 4 , γ = 5 1 /2 (Länge 5,25 mm. Im Uterus ein 0,25 mm langes Ei).</p> <p> 4) α = 35, β = 5 , γ = 5 (Länge 5,25 mm. Im Uterus ein 0,21 mm langes Ei).</p> <p> 5) <i>α</i> = 36, β = 4 1/2, γ = 5 (Länge 5,4 mm. Im Uterus 1 Ei).</p> <p> Den einzigen wichtigen Unterschied zwischen den dänischen und schweizerischen Exemplaren bilden die drei gleichstarken Zähne im hinteren Drittel der Mundhöhle bei den letzteren, deren Spitzen nach hinten gerichtet sind (Fig. 4). Doch glaube ich dieses abweichende Verhalten auf den Umstand zurückführen zu können, daß Ditlevsen nur unreife Weibchen vorlagen, welche allem Anschein nach die letzte Häutung noch nicht absolviert hatten. Näher darauf einzugehen, möge mir an andrer Stelle gestattet sein. Die Geschlechtsorgane sind paarig symmetrisch, kurz. Die Vulva liegt hinter der Körpermitte.</p> <p> Systematische Stellung: <i>Mon</i>. <i>dolichurus</i> Ditl., so, wie er mir vorliegt, hat mit <i>Mon</i>. <i>tridentatus</i> de Man als Übergangsform zu der Gattung <i>Oncholaimus</i> Duj. zu gelten. Bütschli² war der Meinung, daß Bastian "vielleicht nicht mit sehr viel Glück" die Gattung <i>Mononchus</i> von Dujardins <i>Oncholaimus</i> abgetrennt habe, da er den <i>Oncholaimus</i> <i>fovearum</i> Duj., der 3 Zähnchen in der Mundhöhle trägt, in seiner Gattung <i>Mononchus</i> unterbringen mußte. "Und so dürften sich vielleicht", fährt Bütschli fort, "später Übergangsformen zwischen der Gattung <i>Mononchus</i> und den mit ähnlicher Mundhöhle versehenen Meeresnematoden finden, welche die scharfe Trennung dieser Formen wieder fraglich machten. Als eine solche Übergangsform bezeichnet de Man seinen <i>Mon</i>. <i>tridentatus</i>, und ich tue dasselbe von dem mir vorliegenden <i>Mon</i>. <i>dolichurus</i> Ditl., zumal diese Art in Dänemark im Brackwasser lebt und so gewissermaßen eine ideale Mitte hält zwischen den marinen <i>Oncholaimus</i> - Arten und den im Süßwasser lebenden Arten der Gattung <i>Mononchus</i>. Von Interesse dürften in diesem Zu-sammenhang die Untersuchungen von K. Marcinowski ³ sein.</p> <p> Diese scharfsinnige Beobachterin faßt auf Grund der besonders an <i>Mononchus</i> <i>brachyuris</i> Bütschli gewonnenen Üntersuchungsergebnisse die <i>Mononchus</i> -Mundhöhle folgendermaßen auf: "Es bestehen eine Anzahl, vielleicht sechs, längs der Mundhöhle angeordnete Chitinstücke. Drei von ihnen sind besonders kräftig ausgebildet; von diesen dreien trägt eines den Zahn." Die hei <i>Mononchus</i> <i>tridentatus</i> und "der jedenfalls sehr nahestehenden, vielleicht mit Unrecht von <i>Mononchus</i> abgetrennten Gattung <i>Oncholaimus</i> in typischer Weise zutage tretende Dreizahl im Bau der Mundhöhle fände somit eine plausible Erklärung und würde eben diese beiden Gattungen, wie schon Bütschli vor 40 Jahren vermutete, wieder in nahe Beziehungen zueinander bringen. Dabei müßte man freilich annehmen, daß die mit nur einem Zahn ver-sehenen Arten von ursprünglich dreizälnigen abzuleiten wären. Doch werden noch weitere Beobachtungen zur völlgen Klärung dieser Frage notwendig sein.</p>Published as part of <i>Menzel, Rich., 1913, Mononchus zschokkei n. sp. und einige wenig bekannte, für die Schweiz neue freilebende Nematoden, pp. 408-413 in Zoologischer Anzeiger 42</i> on pages 410-411, DOI: <a href="http://zenodo.org/record/10797276">10.5281/zenodo.10797276</a>
Model correction factor method for reliability problems involving integrals of non-Gaussian random fields
No full textThe model correction factor method (MCFM) is used in conjunction with the first-order reliability method (FORM) to solve structural reliability problems involving integrals of non-Gaussian random fields. The approach replaces the limit-state function with an idealized one, in which the integrals are considered to be Gaussian. Conventional FORM analysis yields the linearization point of the idealized limit-state surface. A model correction factor is then introduced to push the idealized limit-state surface onto the actual limit-state surface. A few iterations yield a good approximation of the reliability index for the original problem. This method has application to many civil engineering problems that involve random fields of material properties or loads. An application to reliability analysis of foundation piles illustrates the proposed method. Keywords: Directional simulation on a cone; First order reliability method; Model correction factor method; Nataf field integration; Non-Gaussion random field; Random field integration; Structural reliability; Pile foundation reliabilit
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