510 research outputs found
Are tree roots in the canopy ecologically important? A critical reassessment from a case study in a tropical montane rainforest
No full textBackground: The occurrence of adventitious roots in the crowns of rainforest trees has been reported occasionally. These roots have been suggested to serve as an ecological mechanism that increases nutrient supply to trees. Aim: We investigated the biomass and ecomorphology of tree fine roots in the canopy and in the terrestrial soil in a nutrient-poor montane rainforest in Costa Rica. Methods: Crown humus and terrestrial soil organic layer samples were analysed for tree fine root mass, root morphology and chemical properties. We surveyed crown humus abundance and quantitatively estimated the stand's tree fine root biomass in the canopy. Results: Soil chemical properties were similar in crown humus and terrestrial organic layer samples. Fine root biomass density and live-to-dead ratio were higher in the terrestrial soil than in the crown humus. Tree fine roots in the canopy represented less than 0.1% of the fine root biomass in the terrestrial organic layer. Canopy roots completely lacked ectomycorrhizal colonisation, while terrestrial fine roots were entirely colonised. Conclusions: The negligible biomass of adventitious fine roots in the canopy clearly suggests that the ecological benefit from canopy roots for the host tree must be marginal even under particularly poor growth conditions.German Research Foundation (DFG
Out to Lunch: Saks & koehler Reply to Rudin & Imman\u27s Commentary
No full textAt several points in their comment on our article in Science (1), Rudin & Inman (2, 3) asserted or clearly implied that we had been dishonest in our presentation. In each of those instances Rudin & Inman\u27s charges are groundless, as we demonstrate below.
Had Rudin & Inman examined the actual source [see Fig. 1, right], they would have discovered that the words were indeed those of Moenssens, that they were consistent with the context in which they appeared, that Moenssens was not quoting Zain or anyone else, and that Saks & Koehler had accurately attributed the statement to its author, Andre Moenssens
Mycorrhizal, Endophytic and Ecomorphological Status of Tree Roots in the Canopy of a Montane Rain Forest
No full textOur investigation provides data on the symbiotic status and the functional morphology of tree fine roots in canopy soils of an upper montane forest in Costa Rica. Canopy roots completely lacked mycorrhizal colonization, but showed a high abundance of endophytic fungi suggesting a reduced ability for nutrient acquisition compared with terrestrial roots
Ca/calmodulin dependent kinase II (CaMKII) contributes to disordered Ca homeostasis during doxorubicin treatment
No full textCa/calmodulin dependent kinase II (CaMKII) contributes to disordered Ca homeostasis during doxorubicin treatment
No full textOphiacantha brevispina Koehler 1898
No full textErroneous— <i>Ophiacantha brevispina</i> Koehler, 1898 Reports for the Azores: <p> <i>Ophiacantha brevispina</i> Koehler, 1898 — Bartsch 1987: 120–121, figs. 16, 17.</p> <p> <b>Type locality:</b> Bay of Biscay (46°27’00″N, 4°09’46″W).</p> <p> <b>See:</b> Koehler (1898: 56–57, pl. 8, figs. 43, pl. 9, fig. 44).</p> <p> <b>Occurrence:</b> Northeast Atlantic, from the Bay of Biscay to Dakar in Senegal (Koehler 1898, Bartsch 1987), including Madeira (Jesus & Abreu 1998).</p> <p> <b>Depth:</b> 90–417 m (Bartsch 1987).</p> <p> <b>Habitat:</b> soft sediment, sand to muddy sand (Cadenat 1938).</p> <p> <b>Remarks:</b> few specimens of <i>Ophiacantha brevispina</i> have been found since Koehler (1898) described this species. Cadenat (1938) identified numerous animals from an area that the author referred as Cape Blanc and Cape Verde as <i>Ophiacantha</i> sp., though none of the specimens came from the later archipelago but from Dakar. Regardless Cadenat remarked that these brittle stars were quite close to what Koehler described as <i>Ophiacantha brevispina</i>. Later, Bartsch (1987) recorded <i>O</i>. <i>brevispina</i> from the same region as the previous author. Bartsch erroneously listed the Azores under geographical range of this species (citing Cadenat 1938), mistaking the Cape Verde Islands with the Azores.</p>Published as part of <i>Madeira, Patrícia, Kroh, Andreas, Cordeiro, Ricardo, De, António M., Martins, Frias & Ávila, Sérgio P., 2019, The Echinoderm Fauna of the Azores (NE Atlantic Ocean), pp. 1-231 in Zootaxa 4639 (1)</i> on page 163, DOI: 10.11646/zootaxa.4639.1, <a href="http://zenodo.org/record/3342161">http://zenodo.org/record/3342161</a>
Political militaries in popular uprisings: A comparative perspective on the Arab Spring
No full text© 2016, © The Author(s) 2016. What determines whether militaries will defect from authoritarian incumbents during regime crises? Variance in military behavior in the Arab Spring has given rise to a debate around this issue. This article highlights weaknesses of the dominant explanation and develops an alternative account of military behavior in ‘endgame scenarios’. If militaries are politicized institutions that play a major role in regulating access to power under authoritarianism, they are more likely to intervene during normal times, but less likely to defect during mass uprisings. I quantitatively test this argument against data on military coups between 1975 and 2000 drawing on a new variable that allows me to explicitly model the impact of major regime crises. I illustrate the emergence of different forms of political–military relations and their consequences in the Arab Spring by drawing on evidence from Syria, Egypt, and Tunisia
Circeaster marcelli Koehler 1909
No full textCirceaster marcelli Koehler, 1909 Circeaster marcelli Koehler, 1909: 84, pl. IV, figs 1, 2, pl. VI, fig. 1. — Clark 1993: 251. MATERIAL EXAMINED. — No specimens available for examination. DISTRIBUTION. — Recorded from 7°23'N, 75°44'E in the Indian Ocean. 1926 m (1053 fms). DIAGNOSIS. — R/r = 2.67. Arm plates significantly larger than disk plates.Transition abrupt between abactinal disk and arm plates. Abactinal granules absent. Superomarginals not abutting at midline, arm plates continuous to terminal. Interradial arcs linear.Spinelets and granules with spiny tips cover superomarginal, inferomarginal plates, actinal surface. Seven to eight thick, blunt furrow spines. Prominent paddle-like toothed pedicellariae, separated from furrow spines. Granules identical to actinal surface present on remainder of adambulacral plate. APOMORPHY LIST. — Nodes 14 to Circeaster marcelli: 1.4, abactinal accessories absent; 1.6, no size, accessories absent. DESCRIPTION See Koehler (1909; translation in English of the description is available from the author).Published as part of Mah, Christopher L., 2006, Phylogeny and biogeography of the deep-sea goniasterid Circeaster (Echinodermata, Asteroidea, Goniasteridae) including descriptions of six new species, pp. 917-954 in Zoosystema 28 (4) on page 935, DOI: 10.5281/zenodo.452546
The Sacramental Theory in John 19:26-27
No full textAbout the author: Father Theodore Koehler, S.M., of the Seminaire Marianiste at the University of Fribourg, Switzerland, studied under Father Neubert
Marguerite Zwicker : Watercolours
No full textKoehler-Vandergraaf assesses Zwicker's long career as an artist in Nova Scotia by examining watercolours executed between 1940 and 1991. The author divides these into the categories of landscape, flower painting and still-lifes. Biographical notes. 1 bibl. ref
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