88,138 research outputs found
Root foraging : the consequences for nutrient acquisition and competition in heterogeneous environments
No full textIn natural habitats, the availability of essential mineral nutrients may vary widely from place to place and from time to time, at scales relevant to individual plants. Plants have developed root foraging mechanisms that enable them to acquire adequate amounts of nutrients in these heterogeneous environments. The ability of plants to proliferate roots in nutrient-rich patches has been shown frequently, but both the timing and the degree of root proliferation varied widely. Species from inherently nutrient-rich habitats in general display a higher relative increase in root density in nutrient-rich patches than species from inherently nutrient-poor habitats. This observation prompted the hypothesis that root foraging mechanisms differ between species from habitats of different nutrient availability.Overall, the results described in this thesis contradict this hypothesis. The higher degree of selective root placement displayed by species from more nutrient-rich habitats compared to species from more nutrient-poor habitats may result from differences in growth rate rather than from differences in root morphological plasticity. The results further indicate that selective root placement may confer an advantage in terms of nutrient acquisition in heterogeneous environments in the short-term, but in the long-term the increased root density may result in a lower rather than a higher biomass production in heterogeneous environments. However, root foraging abilities by which local nutrient patches are exploited may still be profitable when plants are grown in competition. The ability to rapidly exploit nutrient-rich patches due to root foraging characteristics seems to confer a competitive advantage in heterogeneous environments, even in the long-term.</p
Figure 16 from: de Gier W, Fransen CHJM (2018) Odontonia plurellicola sp. n. and Odontonia bagginsi sp. n., two new ascidian-associated shrimp from Ternate and Tidore, Indonesia, with a phylogenetic reconstruction of the genus (Crustacea, Decapoda, Palaemonidae). ZooKeys 765: 123-160. https://doi.org/10.3897/zookeys.765.25277
No full textFigure 16 SEM photos dactylus third pereiopod. A Odontonia bagginsi sp. n. B O. sibogae (Bruce, 1972) C O. katoi (Kubo, 1940) D O. rufopunctata Fransen, 2002 E O. seychellensis Fransen, 2002 F O. plurellicola sp. n. G O. maldivensis Fransen, 2006
Bitias stocki Fransen 1990
No full text<i>Bitias stocki</i> Fransen, 1990 <p>(Figs. 1, 2)</p> <p> <i>Bitias stocki</i> Fransen 1990: 68, figs. 1–3; Crosnier & Fransen 1994: 50, fig. 3c–e.</p> <p> <b>Material examined</b>. Southwestern Atlantic Ocean off Brazil: 1 female (pocl 5.3 mm, rl 2.2 mm), TAAF MD 55 / BRÉSIL 1987, off Espírito Santo, eastern slope of Abrolhos Bank, station 43 CB 77, 19º00’S 37º47’W, depth: 790–900 m, 27.V.1987 (MZUSP 31148); 1 ovigerous female (pocl 6.2 mm, rl 2.6 mm), TAAF MD 55 / BRÉSIL 1987, station 43 CB 77, 19º00’S 37º47’W, depth: 790–900 m, 27.V.1987 (MZUSP 31149); 1 male (pocl 6.9 mm, rl 2.9 mm), TAAF MD 55 / BRÉSIL 1987, off Rio de Janeiro, south of Cabo Frio, station 65 CB 106, 23º54’S 42º10’W, depth: 830 m, 02.VI.1987 (MZUSP 31150).</p> <p> <b>Description</b>. For detailed description and illustrations see Fransen (1990); for illustrations of the Brazilian material see Figs. 1 a–g, 2.</p> <p> <b>Distribution</b>. Eastern Atlantic: Azores and Cape Verde, 1100–1350 m (Fransen 1990). Western Atlantic: Brazil, off Espírito Santo and Rio de Janeiro, 790–900 m (present study).</p> <p> <b>Remarks</b>. <i>Bitias stocki</i> was previously known only from the type series: a male holotype and an ovigerous female paratype (allotype) collected at 1320–1350 m south of Pico, Azores, and a female paratype collected at 1100–1300 m southwest of Fogo, Cape Verde (Fransen 1990). The present specimens represent the first record of <i>B. stocki</i> and the genus <i>Bitias</i> from the western Atlantic (Brazil). The Brazilian material agrees well with the type material of <i>B. stocki</i> as described and illustrated by Fransen (1990). The dorsal teeth on the carapace and rostrum are movable (posterior half of the rostrum and carapace posterior to the post-orbital margin) or fixed (distal half of the rostrum); their number ranges from 14 to 16 (Fig. 1 b, f, g). The ventral subdistal tooth may be present or absent and the development of the lateral rostral carina is also variable (Fig. 1 b, f, g).</p> <p> An important morphological feature of <i>B. stocki</i> not mentioned nor illustrated in the original description of the species (Fransen 1990) is the presence of sharp processes on the abdominal sternum. All three Brazilian specimens have a pair of spine-like processes on the first to fourth abdominal sternites, strongest on the first and diminishing in size towards the fourth; the fifth sternite has a small median process continued by a median carina. At our request, Dr. Charles H.J.M. Fransen examined the holotype of <i>B. stocki</i> (RMNH D 39051), in which he found the same armature on the abdominal sternum. Dr. Fransen’s schematic drawing is reproduced here (Fig. 1 h), thereby completing the description of the holotype. The only other presently known species of <i>Bitias</i> is the Indo-West Pacific <i>Bitias brevis</i> (Rathbun, 1906), which differs from <i>B. stocki</i> in only a few very subtle details (Crosnier & Fransen 1994).</p>Published as part of <i>Anker, Arthur, Pachelle, Paulo P. G. & Tavares, Marcos, 2014, Two new species and two new records of deep-water caridean shrimps from Brazil (Decapoda: Pandalidae, Palaemonidae, Crangonidae), pp. 263-278 in Zootaxa 3815 (2)</i> on page 264, DOI: 10.11646/zootaxa.3815.2.6, <a href="http://zenodo.org/record/231091">http://zenodo.org/record/231091</a>
Heinrich J. F. Reinhardt, Die Ehelehre der Schule des Anselms von Laon. Eine theologie- und kirchengeschichtliche Untersuchung zu den Ehetexten der frühen Pariser Schule des 12. Jahrhunderts. Anhang : Edition des Ehetraktates der Sententie Magistri A. (coll. Beiträge zur Geschichte der Philosophie und Theologie des Mittelalters, N.F. Bd 14). 1974
No full textFransen Gérard. Heinrich J. F. Reinhardt, Die Ehelehre der Schule des Anselms von Laon. Eine theologie- und kirchengeschichtliche Untersuchung zu den Ehetexten der frühen Pariser Schule des 12. Jahrhunderts. Anhang : Edition des Ehetraktates der Sententie Magistri A. (coll. Beiträge zur Geschichte der Philosophie und Theologie des Mittelalters, N.F. Bd 14). 1974. In: Revue théologique de Louvain, 9ᵉ année, fasc. 2, 1978. pp. 202-204
Heinrich J. F. Reinhardt, Die Ehelehre der Schule des Anselms von Laon. Eine theologie- und kirchengeschichtliche Untersuchung zu den Ehetexten der frühen Pariser Schule des 12. Jahrhunderts. Anhang : Edition des Ehetraktates der Sententie Magistri A. (coll. Beiträge zur Geschichte der Philosophie und Theologie des Mittelalters, N.F. Bd 14). 1974
No full textFransen Gérard. Heinrich J. F. Reinhardt, Die Ehelehre der Schule des Anselms von Laon. Eine theologie- und kirchengeschichtliche Untersuchung zu den Ehetexten der frühen Pariser Schule des 12. Jahrhunderts. Anhang : Edition des Ehetraktates der Sententie Magistri A. (coll. Beiträge zur Geschichte der Philosophie und Theologie des Mittelalters, N.F. Bd 14). 1974. In: Revue théologique de Louvain, 9ᵉ année, fasc. 2, 1978. pp. 202-204
Strontium
No full text"Prepared by Syracuse Research Corporation under contract no. 205-1999-00024; prepared for U.S. Dept. of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry."Chemical manager(s)/author(s): Alfred F. Dorsey, ATSDR, Division of Toxicology, Atlanta, GA; Margaret E. Fransen, Gary L. Diamond, Richard J. Amata, Syracuse Research Corporation, North Syracuse, NY.Includes bibliographical references (p. 277-365).205-1999-0002
FIG. 5. — Odontonia maldivensis n in On Pontoniinae (Crustacea, Decapoda, Palaemonidae) collected from ascidians
No full textFIG. 5. — Odontonia maldivensis n. sp., Maldives (MNHN-Na 15236): A-D, ovigerous ♀ holotype, pocl. 2.5 mm; E, F, ♂ allotype, pocl. 2.2 mm; A, third pereiopod; B, idem, dactylus; C, fifth pereiopod; D, idem, dactylus; E, appendix interna and appendix masculina ofPublished as part of Fransen, Charles H. J. M., 2006, On Pontoniinae (Crustacea, Decapoda, Palaemonidae) collected from ascidians, pp. 713-746 in Zoosystema 28 (3) on page 723, DOI: 10.5281/zenodo.539239
FIG. 13. — Periclimenaeus orbitocarinatus n in On Pontoniinae (Crustacea, Decapoda, Palaemonidae) collected from ascidians
No full textFIG. 13. — Periclimenaeus orbitocarinatus n. sp., ovigerous ♀ holotype, pocl. 2.3 mm, Loyalty Islands (MNHN-Na 15253): A, anterior region, dorsal aspect; B, idem, lateral aspect; C, abdomen, lateral aspect; D, telson; E, antennula; F, antenna; G, mandible; H, maxillula;Published as part of Fransen, Charles H. J. M., 2006, On Pontoniinae (Crustacea, Decapoda, Palaemonidae) collected from ascidians, pp. 713-746 in Zoosystema 28 (3) on page 733, DOI: 10.5281/zenodo.539239
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