3,499 research outputs found
Polymer multimode waveguide optical and electronic PCB manufacturing
No full textThe paper describes the research in the £1.3 million IeMRC Integrated Optical and Electronic Interconnect PCB Manufacturing (OPCB) Flagship Project in which 8 companies and 3 universities carry out collaborative research and which was formed and is technically led by the author. The consortium’s research is aimed at investigating a range of fabrication techniques, some established and some novel, for fabricating polymer multimode waveguides from several polymers, some formulations of which are being developed within the project. The challenge is to develop low cost waveguide manufacturing techniques compatible with commercial PCB manufacturing and to reduce their alignment cost. The project aims to take the first steps in making this hybrid optical waveguide and electrical copper track printed circuit board disruptive technology widely available by establishing and incorporating waveguide design rules into commercial PCB layout software and transferring the technology for fabricating such boards to a commercial PCB manufacturer. To focus the research the project is designing an optical waveguide backplane to tight realistic constraints, using commercial layout software with the new optical design rules, for a demonstrator into which 4 daughter cards are plugged, each carrying an aggregate of 80 Gb/s data so that each waveguide carries 10 Gb/s
Yr ‘Hen dri ohonom’: gwrywdod, y personol a’r cyhoeddus yn y cyfeillgarwch rhwng D.R. Daniel, Tom Ellis ac O.M. Edwards
No full textFfocws y traethawd hwn yw’r berthynas rhwng D.R. Daniel, Tom Ellis ac O.M. Edwards. Roeddent oll yn ddynion cyhoeddus amlwg yn eu dydd, ond roedd cwlwm cyfeillgarwch ar lefel bersonol wedi’i hen sefydlu rhyngddynt yn ystod cyfnod bachgendod. Ystyried natur, a mesur dyfnder yr ymlyniad hwn a wneir yn yr astudiaeth hon gan gyfeirio at gyfeillgarwch Daniel a David Lloyd George yn ogystal er mwyn cyfoethogi’r ddadl, a chynnig gwrthgyferbyniad.
Cynigir mewnwelediad dynol i gymeriadau a phrofiadau Daniel, Ellis, Edwards a Lloyd George wrth ystyried eu dealltwriaeth hwy o bersonoliaethau’i gilydd a’r modd yr oeddent yn cyflwyno eu hunain i’w cyfeillion yn eu gohebiaeth. Ymhellach, cyfrenir at y feirniadaeth o’r cysyniad o sfferau ar wahân o safbwynt cyfeillion gwrywaidd. Dengys y modd y bu i Daniel, Ellis ac Edwards rannu profiadau cyhoeddus a phersonol gyda’i gilydd ar hyd taith bywyd. Plethwyd eu profiadau wrth iddynt groesi trothwyon academaidd a gyrfaol ynghyd â phriodi a sefydlu teulu.
Canolbwynt yr astudiaeth hon yw mesur a chloriannu dyfnder y rhwym a fodolai rhwng Daniel, Ellis ac Edwards, ynghyd â Daniel a Lloyd George. Dadleuir bod ymlyniad hynod ddwfn rhyngddynt a adlewyrchir yn y modd y byddent yn troi at ei gilydd am gynhaliaeth mewn cyfnodau heriol. Mae’r datganiadau emosiynol, y gofal gwirioneddol a’r syniad o alar a cholled pan ddaw’r cyfeillgarwch i ben yn cyflwyno gwedd newydd ar y cysyniadau o wrywdod a chyfeillgarwch rhwng dynion ar ddiwedd y bedwaredd ganrif ar bymtheg a dechrau’r ugeinfed.
Gosodir y perthynasau rhwng y dynion dan sylw yn eu cyd-destun gan ystyried y modd roedd rhywdweithiau teuluol ehangach wedi eu sefydlu o ganlyniad i’w cyfeillgarwch, er i raddau amrywiol. Dyma arddangos lefel y cysylltiad rhwng Daniel, ei gyfeillion a’u
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teuluoedd sy’n cyfoethogi’n dealltwriaeth o’r ymlyniad rhyngddynt a gwmpasai brofiadau personol a chyhoeddus
Platythelphusa A. Milne-Edwards 1887
No full textGENUS PLATYTHELPHUSA A. MILNE- EDWARDS, 1887 (FIGS 1B 3 [3], 5J–L, 10C; TABLES 1–3) Platythelphusa A. Milne-Edwards, 1887: 146; Hilgendorf, 1898: 21; Moore, 1903: 286; Rathbun, 1905: 268; Cunnington, 1907: 266–268; 1920: 557; Alcock, 1910: 253–261; Colosi, 1920: 9–10; Balss, 1936: 196; Chace, 1942: 224; Cumberlidge, 1999: 16, 17, 25, 36, 37, 42, 45, 66–69, 74, 76–79, 100–113, 116, 317; 2008: 72, 77, tab. 1; 2011: 79, 82–83, tabs 6.1, 6.3; Cumberlidge et al., 1999: 1491–1493; Marijnissen et al., 2004: 515; Ng et al., 2008: 171. Limnothelphusa Cunnington, 1899: 698; Moore, 1903: 280; Rathbun, 1905: 269. Hydrothelphusa (Platythelphusa) Bouvier, 1917a: 615–621; 1917b: 657–659; 1921: 41. Potamonautes (Platythelphusa) Bott, 1955: 226–229; Coulter, 1991: 253–257. Potamonautes (Obesopotamonautes) Bott, 1955: pl. XII: figs 1a–d, 17, 18, 79a, b (partim, for Potamon (Potamonautes) langi Rathbun, 1921; not Thelphusa obesa A. Milne-Edwards, 1868 (= Maritimonautes obesus) or Potamon (Potamonautes) calcaratus Gordon, 1929 (= Maritimonautes calcaratus). Diagnosis: Third maxilliped ischium smooth, lacking vertical sulcus (or with faint vertical sulcus); thoracic sternal sulcus S3/4 deep, completely traversing sternum (or deep only at sides, faint in middle). Distribution: Platythelphusa includes 11 species with a distribution centred on Lake Tanganyika and its drainage basin (in Malawi, Tanzania, D.R. Congo, Rwanda and Burundi), except for two species from the D.R. Congo: Platythelphusa langi from Tshopo Province and Platythelphusa idjwiensis from Lake Kivu in Nord-Kivu Province (Cumberlidge et al., 1999; Marijnissen et al., 2004; Reed & Cumberlidge, 2006a; Cumberlidge, 2015; Fig. 10C). Type species: Platythelphusa armata A. Milne- Edwards, 1887, by monotypy. Species included: Platythelphusa armata A. Milne- Edwards, 1887, Platythelphusa conculcata (Cunnington, 1907), Platythelphusa denticulata Capart, 1952, Platythelphusa echinata Capart, 1952, Platythelphusa idjiwiensis (Chace, 1942) comb. nov., Platythelphusa immaculata Marijnissen, Schram, Cumberlidge & Michel, 2004, Platythelphusa langi (Rathbun, 1921) comb. nov., Platythelphusa maculata (Cunnington, 1902), Platythelphusa polita Capart, 1952, Platythelphusa praelongata Marijnissen, Schram, Cumberlidge & Michel, 2004, Platythelphusa tuberculata Capart, 1952. Remarks: The subgenus Potamonautes (Platythelphusa) Bott, 1955 is reestablished, revised and given genus status here to accommodate 11 species: all nine Platythelphusa species from Lake Tanganyika, plus Pl. langi (now Platythelphusa) from the Upper Congo Basin in the D.R. Congo and Pl. idjwiensis (now Platythelphusa) from Lake Kivu. Daniels et al. (2015: fig. 1), Daniels & Klaus (2018: fig. 1) and Wood et al. (2019: fig. 1) and the present study (Fig. 1B 3) all group these species together in a well-supported clade within the Potamonautini. Platythelphusa has two clear lineages within it, with one branch for the nine species endemic to Lake Tanganyika, and the other branch for species from the Upper Congo Basin in the D.R. Congo (including Lake Kivu). Bott (1955) established the subgenus Po. (Platythelphusa) for Po. (Pl.) armata armata and Po. (Pl.) a. conculcata. The genus as revised here retains the name Platythelphusa because it includes the type species Platythelphusa armata A. Milne-Edwards, 1887. DNA data are available for ten of these species (Daniels et al., 2015: fig. 1; Daniels & Klaus, 2018: fig. 1; Wood et al., 2019: fig. 1; Fig. 1B 3). The remaining species, Pl. denticulata, is included here based on shared morphological characters that conform to the generic diagnosis (Cumberlidge et al., 1999). One of the species included here in Platythelphusa [Potamon (Potamonautes) langi Rathbun, 1921] was assigned by Bott (1955) as the type species of the subgenus Potamonautes (Obesopotamonautes) Bott, 1955. Despite this, the genus name for these species remains as Platythelphusa by priority because the type species of the latter genus (Platythelphusa armata A. Milne-Edwards, 1887) was described before Potamon (Potamonautes) langi Rathbun, 1921. All but one species assigned to Platythelphusa share the following characters: a distinct postfrontal crest that completely traverses the carapace between the epibranchial teeth, a small exorbital tooth, an epibranchial tooth reduced to a small granule, one or more long, sharp teeth lining the anterolateral margin of carapace, and a cheliped carpus with two subequal long, sharp teeth. Pl. idjwiensis is included because of phylogenetic evidence that positions it in the same clade as the other congeners (Fig. 1B 3 [3]) despite the fact that Pl. idjwiensis lacks a postfrontal crest, has a completely smooth anterolateral margin that lacks teeth, and has a small reduced proximal tooth on the cheliped carpus inner margin.Published as part of Cumberlidge, Neil & Daniels, Savel R., 2022, A new multilocus phylogeny reveals overlooked diversity in African freshwater crabs (Brachyura: Potamoidea): a major revision with new higher taxa and genera, pp. 1268-1311 in Zoological Journal of the Linnean Society 194 (4) on pages 1295-1296, DOI: 10.1093/zoolinnean/zlab082, http://zenodo.org/record/646147
Mycobacterium tuberculosis, but not vaccine BCG, specifically upregulates matrix metalloproteinase-1
No full textRationale: Pulmonary cavitation is fundamental to the global success of Mycobacterium tuberculosis. However, the mechanisms of this lung destruction are poorly understood. The biochemistry of lung matrix predicts matrix metalloproteinase (MMP) involvement in immunopathology.Methods: We investigated gene expression of all MMPs, proteins with a disintegrin and metalloproteinase domain, and tissue inhibitors of metalloproteinases in M. tuberculosis–infected human macrophages by real-time polymerase chain reaction. MMP secretion was measured by zymography and Western analysis, and expression in patients with pulmonary tuberculosis was localized by immunohistochemistry.Results: MMP-1 and MMP-7 gene expression and secretion are potently upregulated by M. tuberculosis, and no increase in tissue inhibitor of metalloproteinase expression occurs to oppose their activity. Dexamethasone completely suppresses MMP-1 but not MMP-7 gene expression and secretion. In patients with active tuberculosis, macrophages express MMP-1 and MMP-7 adjacent to areas of tissue destruction. MMP-1 but not MMP-7 expression and secretion are relatively M. tuberculosis specific, are not upregulated by tuberculosis- associated cytokines, and are prostaglandin dependent. In contrast, the vaccine M. bovis bacillus Calmette-Guérin (BCG) does not stimulate MMP-1 secretion from human macrophages, although M. tuberculosis and BCG do upregulate MMP-7 equally. BCG-infected macrophages secrete reduced prostaglandin E2 concentrations compared with M. tuberculosis–infected macrophages, and prostaglandin pathway supplementation augments MMP-1 secretion from BCG-infected cells.Conclusions: M. tuberculosis specifically upregulates MMP-1 in a cellular model of human infection and in patients with tuberculosis. In contrast, vaccine BCG, which does not cause lung cavitation, does not upregulate prostaglandin E2–dependent MMP-1 secretion
The Systematic Position of Heloecius Cordiformis (H. Milne Edwards, 1837) (Decapoda, Ocypodidae) as Revealed by Larval Morphology
No full textLe premier stade zoé à'Heloecius cordiformis (H. Milne Edwards, 1837) est décrit et figuré. D'après ses caractères larvaires, il est difficile d'inclure cette espèce dans l'une des sous-familles actuellement considérées comme formant la famille des Ocypodidae. Ceci vient à l'appui de la suggestion de Türkay (1983), fondée sur les caractères de l'adulte, suivant laquelle Heloecius cordiformis devrait être exclu de la sous-famille des Ocypodinae et placé dans celle des Heloeciinae
Mrs. Don Fritz Cockrell Collection
No full textPhotograph of "Old Joe and Ives," horses owned by Mrs. L.J. Edwards and Mrs. D.R. Boyd, Norman, Indian Territory
Amplitude of accommodation in type 1 diabetes
No full textFree to read\ud
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<b>Purpose</b>\ud
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People with diabetes have accelerated age-related biometric ocular changes compared with people without diabetes. We determined the effect of type 1 diabetes on amplitude of accommodation.\ud
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<b>Methods</b>\ud
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There were 43 participants (33 ± 8 years) with type 1 diabetes and 32 (34 ± 8 years) age-balanced controls. There was no significant difference in mean equivalent refractive error and visual acuity between the groups. Amplitude of accommodation was measured using two techniques: objective by determining the accommodative response to a stimulus in a COAS-HD wavefront aberrometer and subjective with a Badal hand optometer. Influences of age and diabetes duration on amplitude of accommodation were analyzed using multiple regression analysis.\ud
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<b>Results</b>\ud
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People with diabetes had lower objective (2.7 ± 1.6 diopters [D]) and subjective (4.0 ± 1.7 D) amplitudes than controls (objective 4.1 ± 2.1 D, subjective 5.6 ± 2.1 D). Across both groups, objective amplitude was less than subjective amplitude by 1.4 ± 1.2 D. For objective amplitude and the whole group, the duration of diabetes contributed 57% variation to the loss of amplitude relative to that provided by age. For the objective amplitude and only the diabetes group, this was 78%. For subjective amplitude, the corresponding proportions were 68% and 103%.\ud
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<b>Conclusions</b>\ud
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Lowered amplitude of accommodation exists in individuals with type 1 diabetes when compared with age-matched controls. The loss correlated strongly with duration of diabetes. The results suggest that individuals with diabetes will experience presbyopia earlier in life than people without diabetes, mainly due to changes in the lens
A theoretical study of the performance of resistojet nozzles
No full textThe theoretical development of four computer models of resistojet nozzle performance is reported. Five main energy loss processes are accounted for; these are (i) frozen chemical rate processes, (ii) finite rate vibrational relaxation, (iii) incomplete expansion, (iv) viscous flow and (v) radial flow.The nozzle flow is assumed to be composed of an inviscid core and a viscous boundary layer, where the boundary layer is represented by the patching together of similar solutions of the laminar boundary layer equations. General similar boundary layer equations have been developed which include the radial dependences accounting for transverse curvature. Four simplified classes of similar equations are identified, and extensive solutions have been obtained for the Falkner-Skan equation and a modified Falkner-Skan equation which includes the effects of transverse curvature, over the range of pressure gradient parameter, g, from 0. to 10. Vibrational relaxation is modelled by using an approximate sudden freezing criterion.Performance predictions are presented for H2, CH4, CO2 and NH3 for plenum temperatures extending from 300 to 3000°K and plenum pressures from 200 to 10 kNm-2. A wide variety of nozzle geometries is also considered. The results are compared with the predictions of the slender channel model of Rae and with experimental measurements
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