53,364 research outputs found
Macrofaunal production along the UK continental shelf
No full textEstimates of secondary production (P/B ratio and total production) by macrobenthic communities across the UK continental shelf are presented. Values for individual sampling stations varied from 0.21 to 4.1y-1 for community P/B and 3.1 to 897.2kJm-2y-1 for total production. Such data fills an important gap pertaining to our understanding of the spatial variation in production estimates for this region. Benthic production estimates varied primarily at small (inter-station) scales (24nm), although larger-scale differences were observed. In general, the highest production estimates were exhibited by benthic communities in Cardigan Bay (Irish Sea) and East English Channel, while the lowest estimates were observed for the mid- and northern North Sea areas. The former were typified by shallow, gravelly areas of seabed which exhibit high bed tidal stress and do not thermally stratify during the summer months. On average, annelids contribute an overwhelming majority of the total production with different regions varying in the relative contributions from other phyla such as molluscs, crustaceans and echinoderms.Spatial heterogeneity of sediment granulometric variables occurred primarily between stations while those of other variables (e.g., depth, stratification, and tidal bed stress) were more regional. Although a large proportion of the spatial variation in secondary production estimates was not explained by environmental characteristics, the data indicate that such relationships are scale-dependent. Average bed temperature was a significant factor in creating some of the observed differences at large spatial scales. The possible reasons why a larger proportion of the variation in production estimates was not explained by the present study are presented.</p
The termites of the Mayombe Forest Reserve, Congo (Brazzaville): transect sampling reveals an extremely high diversity of ground-nesting soil feeders
No full textEggleton, P., Davies, R. G., Connetable, S., Bignell, D. E., Rouland, C. (2002): The termites of the Mayombe Forest Reserve, Congo (Brazzaville): transect sampling reveals an extremely high diversity of ground-nesting soil feeders. Journal of Natural History 36 (10): 1239-1246, DOI: 10.1080/00222930110048918, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293011004891
On Eggleton and Guy conjectured upper bound for the crossing number of the n-cube
No full text. The crossing number (G) of a graph G is the smallest integer such that there is a drawing for G with (G) crossings of edges. Let Q n denote the n--dimensional cube. Eggleton and Guy conjectured in 1970 that (Q n ) 4 n 5 32 \Gamma 2 n\Gamma2 b n 2 +1 2 c. We exhibit a drawing for n = 6 with the same value of Eggleton and Guy's conjectured upper bound. We construct a family of drawings for the n--cubes, n 7, with number of crossings 165 1024 4 n \Gamma 2n 2 \Gamma11n+34 2 2 n\Gamma2 , establishing a new upper bound for (Q n ). Our family of drawings confirms Eggleton and Guy's conjectured upper bound when n = 7 and 8. In addition, our upper bound improves the upper bound (Q n ) 4 n 1 6 \Gamma2 n\Gamma3 n 2 \Gamma 2 n\Gamma4 3 + (\Gamma2) n 1 48 due to Madej. AMS Subject Classification: 05C10 Keywords: topological graph theory, crossing numbers 1 Introduction A simple drawing D(G) of a graph G is a drawing of G on the plane such that no edge crosses its..
Photosensitive post tuning of chalcogenide photonic crystal waveguides
No full textThis paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/abstract.cfm?URI=oe-15-3-1277. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.We present experimental results on post-tuning the dispersion of a two-dimensional photonic crystal waveguide made from Ge(33)As(12)Se(55) chalcogenide glass by exploiting the material photosensitivity to near-bandgap light. The change in the refractive index and volume of the material in response to exposure to 633nm light resulted in a shift of more than 5nm in the resonant coupling wavelength between a tapered optical fiber and the modes of a W1 waveguide. This represents a first proof of principle demonstration of the photosensitive post-tuning of a planar photonic crystal device.Michael W. Lee, Christian Grillet, Cameron L. C. Smith, David J. Moss, Benjamin J. Eggleton, Darren Freeman, Barry Luther-Davies, Steve Madden, Andrei Rode, Yinlan Ruan, and Yong-hee Le
Fluid shear contributions to bacteria cell detachment initiated by a monoclonal antibody
No full textReceptor-mediated adhesion of bacteria to biological surfaces is a significant step leading to infection. Due to an increase in bacterial antibiotic resistance, novel methods to block and disrupt these specific interactions have gained considerable interest as possible therapeutic strategies. Recently, several monoclonal antibodies specific for the Staphylococcus aureus collagen receptor demonstrated specialized ability to displace attached cells from collagen in static assays. In this study, we experimentally examine the monoclonal antibody detachment functionality under physiological shear conditions to evaluate the role of this parameter in the detachment process. The detachment of staphylococci from collagen was quantified in real-time using a parallel plate flow chamber, phase contrast video-microscopy and digital image processing. The results demonstrate a unimodal dependence of detachment on fluid wall shear rate. The observed decrease in effective detachment rate with increasing force at the highest shear levels evaluated is counterintuitive and has not been previously demonstrated. Several possible mechanisms of this result are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Letter from C. D. Dawson, Tusayan Copper Mining and Smelting, to Carl Hayden
No full textLetter from C. D. Dawson to Carl Hayden urging him to consider the rights of miners and farmers when drawing up the boundaries for the proposed park
High performance Bragg gratings in chalcogenide glass rib waveguides written with a modified Sagnac interferometer: fabrication and characterization
No full textWe report high performance Bragg gratings in As₂S₃ chalcogenide glass rib waveguides, written with a modified Sagnac interferometer for the first time. Grating growth dynamics obtained from an in-situ monitoring system are presented and analyzedM. Shokooh-Saremi, V. G. Ta’eed, N. J. Baker, I. C. M. Littler, D. J. Moss, B. J. Eggleton, Y. Ruan and B. Luther-Davie
Figure 10 in Termite soldier defence strategies: a reassessment of Prestwich's classification and an examination of the evolution of defence morphology using extended eigenshape analyses of head morphology
No full textFigure 10. The EES axes and values of morphometric variation that support a revised soldier defence classification. a, Planicapritermes; b, Dihoplotermes; c, Cavitermes; d, Termes.Published as part of Scholtz, Olivia I., Macleod, Norman & Eggleton, Paul, 2008, Termite soldier defence strategies: a reassessment of Prestwich's classification and an examination of the evolution of defence morphology using extended eigenshape analyses of head morphology, pp. 631-650 in Zoological Journal of the Linnean Society 153 (4) on page 644, DOI: 10.1111/j.1096-3642.2008.00396.x, http://zenodo.org/record/544604
- …
