137,022 research outputs found
Red Arnberg and Ted Koehler at Marigold Gardens
No full textJohn Alderman, Ruth Etting's stepson, donated these photographs to the Ruth Etting Collection in response to a request from John Moran, the compiler of the collection.Photograph of Red Arnberg and Ted Koehler outside at Marigold Gardens where Ruth Etting first worked as a singerverso: Red Arnberg - Ted Coler [crossed out] Koehler, Marigold Gardens, Chicago 191
Fig. 1. Psolus tessellatus Koehler, 1896. A. Dorsal view. B. Buccal cone. C. Anal cone. D in Redescription of Psolus tessellatus Koehler, 1896 (Echinodermata, Holothuroidea) with neotype designation
No full textFig. 1. Psolus tessellatus Koehler, 1896. A. Dorsal view. B. Buccal cone. C. Anal cone. D. Ventral view.Published as part of Massin, Claude, 2013, Redescription of Psolus tessellatus Koehler, 1896 (Echinodermata, Holothuroidea) with neotype designation, pp. 1-5 in European Journal of Taxonomy 38 on page 2, DOI: 10.5852/ejt.2013.38, http://zenodo.org/record/381398
Ophiacantha veterna Koehler 1907
No full text<i>Ophiacantha veterna</i> Koehler, 1907a <p>Fig. 6A–B</p> <p> <i>Ophiacantha veterna</i> Koehler, 1907a: 41–43.— Koehler 1909: 189–190, pl. 29(3–4). — Koehler 1921 b: 2.— Martynov & Litvinova 2008: 96–97, fig. 11d.</p> <p> <i>Ophiacantha enopla veterna</i>.— Paterson 1985: 37, fig. 16.— Stöhr & Segonzac 2005: 392.</p> <p> <b>Material examined</b>. MD 50 CP7, MNHN IE.2009.1562 (2). MD 50 CP113, MNHN IE.2009.1563 (1).</p> <p>Distribution. Arctic (1992–1995 m), NE Atlantic (1350–2669 m), E Atlantic (1004–1679 m), SPA (940–1680 m).</p> <p> Remarks. The MD 50 specimens are 6.5–7.0 mm dd, disc pentagonal or slightly indented interradially, with margin covered in small rugose granules and centre with small cylindrical spines with terminal thorns, radial shields raised and rib like with oval distal section exposed (Fig. 6A), oral shields trapezoid to hemispherical, two times as wide as long, three to four conical to capitate rugose oral papillae (Fig. 6B), DAPs fan to kite-shaped and separate, to eight arm spines with tiny thorns, upper to three segments long and one tiny spiniform thorny tentacle scale. They are morphologically consistent with material from the North Atlantic including the type description. Although Paterson (1985) considered this species to be a subspecies of <i>Ophiacantha enopla</i> Verrill, 1885, Martynov & Litvinova (2008) re-established <i>O. veterna</i> as a full species. Paterson’s (1985) record of this species from 101 m is a depth outlier that requires re-examination. All other records are from 1000–2700 m.</p>Published as part of <i>O'Hara, Timothy D. & Thuy, Ben, 2022, Biogeography and taxonomy of Ophiuroidea (Echinodermata) from the Îles Saint- Paul and Amsterdam in the southern Indian Ocean, pp. 1-49 in Zootaxa 5124 (1)</i> on pages 16-17, DOI: 10.11646/zootaxa.5124.1.1, <a href="http://zenodo.org/record/6404674">http://zenodo.org/record/6404674</a>
An inverse analysis reveals limitations of the soil-CO<sub>2</sub> profile method to calculate CO<sub>2</sub> production and efflux for well-structured soils
No full textSoil respiration is the second largest flux in the global carbon cycle, yet the underlying below-ground process, carbon dioxide (CO2) production, is not well understood because it can not be measured in the field. CO2 production has frequently been calculated from the vertical CO2 diffusive flux divergence, known as "soil-CO2 profile method". This relatively simple model requires knowledge of soil CO2 concentration profiles and soil diffusive properties. Application of the method for a tropical lowland forest soil in Panama gave inconsistent results when using diffusion coefficients (D) calculated based on relationships with soil porosity and moisture ("physically modeled" D). Our objective was to investigate whether these inconsistencies were related to (1) the applied interpolation and solution methods and/or (2) uncertainties in the physically modeled profile of D. First, we show that the calculated CO2 production strongly depends on the function used to interpolate between measured CO2 concentrations. Secondly, using an inverse analysis of the soil-CO2 profile method, we deduce which D would be required to explain the observed CO2 concentrations, assuming the model perception is valid. In the top soil, this inversely modeled D closely resembled the physically modeled D. In the deep soil, however, the inversely modeled D increased sharply while the physically modeled D did not. When imposing a constraint during the fit parameter optimization, a solution could be found where this deviation between the physically and inversely modeled D disappeared. A radon (Rn) mass balance model, in which diffusion was calculated based on the physically modeled or constrained inversely modeled D, simulated observed Rn profiles reasonably well. However, the CO2 concentrations which corresponded to the constrained inversely modeled D were too small compared to the measurements. We suggest that, in well-structured soils, a missing description of steady state CO2 exchange fluxes across water-filled pores causes the soil-CO2 profile method to fail. These fluxes are driven by the different diffusivities in inter- vs. intra-aggregate pores which create permanent CO2 gradients if separated by a "diffusive water barrier". These results corroborate other studies which have shown that the theory to treat gas diffusion as homogeneous process, a precondition for use of the soil-CO2 profile method, is inaccurate for pore networks which exhibit spatial separation between CO2 production and diffusion out of the soil
Group Decision and Deliberation: A Distributed Detection Process
No full textEdited Derek J. Koehler and Nigel Harve
The effect of the addition of alternative protein sources to swine nursery diets on pig performance
No full textCorrigan, B. P.; Grinstead, G. S.; Koehler, D. D.. (2006). The effect of the addition of alternative protein sources to swine nursery diets on pig performance. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/157272
Ophiacantha sociabilis Koehler 1897
No full text<i>Ophiacantha sociabilis</i> Koehler, 1897: 348, pl. 8 figs 62–63. <p>Figure 4H</p> <p> <b>Material examined</b></p> <p>INDIAN OCEAN • 8 specimens; off Kenya; 03°23’S, 044°04’E; 3960–3980 m; 13 Mar. 1951; Galathea II stn. 238; Globigerina ooze, NHMD-867440 • 7 specimens; Sri Lanka; 03°38’N, 078°15’E; 3310 m; 10 Apr. 1951; Galathea II stn. 281; Globigerina ooze; NHMD-867267, NHMD-867211 • 26 specimens; off Sri Lanka; 05°32’N, 078°41’E; 4040 m; 11 Apr. 1951; Galathea II stn. 282; blackish mud; NHMD-867291.</p> <p> <b>Remarks</b></p> <p> The Galathea samples from the Indian Ocean identified as <i>O</i>. <i>sociabilis</i> differ from the Pacific and Antarctic specimens in having 4–5 pointed lateral oral papillae, the distal one not enlarged, the jaws are wider than in <i>O</i>. <i>pacifica</i> and the oral shield is longer and the lateral edges more rounded. <i>Ophiacantha sociabilis</i> was originally described from the Andaman Islands and Bay of Bengal (Koehler 1897), and it seems advisable to preserve this name for the Indian Ocean population until more data are available.</p>Published as part of <i>Stöhr, Sabine & O'Hara, Timothy D., 2021, Deep-sea Ophiuroidea (Echinodermata) from the Danish Galathea II Expedition 1950 - 52, with taxonomic revisions, pp. 505-529 in Zootaxa 4963 (3)</i> on page 522, DOI: 10.11646/zootaxa.4963.3.6, <a href="http://zenodo.org/record/4704429">http://zenodo.org/record/4704429</a>
Indications of nitrogen-limited methane uptake in tropical forest soils
No full textIt is estimated that tropical forest soils contribute 6.2 Tg yr−1 (28%) to global methane (CH4) uptake, which is large enough to alter CH4 accumulation in the atmosphere if significant changes would occur to this sink. Elevated deposition of inorganic nitrogen (N) to temperate forest ecosystems has been shown to reduce CH4 uptake in forest soils, but almost no information exists from tropical forest soils even though projections show that N deposition will increase substantially in tropical regions. Here we report the results from two long-term, ecosystem-scale experiments in which we assessed the impact of chronic N addition on soil CH4 fluxes from two old-growth forests in Panama: (1) a lowland, moist (2.7 m yr−1 rainfall) forest on clayey Cambisol and Nitisol soils with controls and N-addition plots for 9–12 yr, and (2) a montane, wet (5.5 m yr−1 rainfall) forest on a sandy loam Andosol soil with controls and N-addition plots for 1–4 yr. We measured soil CH4 fluxes for 4 yr (2006–2009) in four replicate plots (40 m × 40 m each) per treatment using vented static chambers (four chambers per plot). CH4 fluxes from the lowland control plots and the montane control plots did not differ from their respective N-addition plots. In the lowland forest, chronic N addition did not lead to inhibition of CH4 uptake; instead, a negative correlation of CH4 fluxes with nitrate (NO3–) concentrations in the mineral soil suggests that increased NO3– levels in N-addition plots had stimulated CH4 consumption and/or reduced CH4 production. In the montane forest, chronic N addition also showed negative correlation of CH4 fluxes with ammonium concentrations in the organic layer, which suggests that CH4 consumption was N limited. We propose the following reasons why such N-stimulated CH4 consumption did not lead to statistically significant CH4 uptake: (1) for the lowland forest, this was caused by limitation of CH4 diffusion from the atmosphere into the clayey soils, particularly during the wet season, as indicated by the strong positive correlations between CH4 fluxes and water-filled pore space (WFPS); (2) for the montane forest, this was caused by the high WFPS in the mineral soil throughout the year, which may not only limit CH4 diffusion from the atmosphere into the soil but also favour CH4 production; and (3) both forest soils showed large spatial and temporal variations of CH4 fluxes. We conclude that in these extremely different tropical forest ecosystems there were indications of N limitation on CH4 uptake. Based on these findings, it is unlikely that elevated N deposition on tropical forest soils will lead to a rapid reduction of CH4 uptake
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