49 results on '"Langley, R."'
Search Results
2. Phase 3 Trials of Ixekizumab in Moderate-to-Severe Plaque Psoriasis
- Author
-
Gordon, K. B, Blauvelt, A., Papp, K. A., Langley, R. G., Luger, T., Ohtsuki, M., Reich, K., Amato, D., Ball, S. G., Braun, D. K., Cameron, G. S., Erickson, J., Konrad, R. J., Muram, T. M., Nickoloff, B. J., Osuntokun, O. O., Secrest, R. J., Zhao, F., Mallbris, L., Leonardi, C. L., Uncover, 1 Study Group: Holly Hake Harris, Matheson, Robert T., Michael, Bukhalo, John H., Tu, Crowley, Jeffrey J., Grande, Kimberly K., Adnan, Nasir, Boni Elizabeth Elewski, James Alan Solomon, Liebhild, Stratmann, Claudia, Buettner, Thomas Peter Dirschka, Margrit Ruth Simon, Jens, Ulrich, Christine, Grigat, Mathias, Augustin, Andrei, Khariouzov, Gerhard, Sattler, Hans Michael Ockenfels, Fredrick Richard Behringer, Hector, Wiltz, Francisco, Flores, Kuettel, Kevin D., Ira Hughes Thorla, Jeffrey Keith Moore, Waterman, Gary L., George Joji Murakawa, Scott Alfred Fretzin, Frankel, Ellen H., Sunil Sharan Dhawan, Lucyna, Leszniewska, Maria, Poznanska, Anna Sobieszek Kundro, Chodorowska, Grazyna M., Katarzyna Turek Urasinska, Romuald, Maleszka, Andrzej, Kaszuba, Lidia, Rajzer, Elizbieta Barbara Szymanska, Lidia, Rudnicka, Neil James Korman, Jamie Debra Weisman, Truett, Artis P., Jeffry, Jacqmein, Steven Robert Cohen, Heller, Gary L., Jenkin, Peter J., Abe, Marcadis, George Sorin Tiplica, Anca Aghinitei Zbranca Toporas, Simona Laura Ianosi, Ion, Florea, Claus, Zachariae, Lars, Iversen, Annalisa, Patrizi, Romanelli, Marco, Christopher, Griffiths, John Berth Jones, John, Foerster, Savin, Ronald C., Nelson, Christopher G., Lyn Carol Chamberlain Guenther, Albrecht, Lorne E., Hong, Chih ho H., Arnon, Katz, Mani, Raman, Adam, David N., Aamir, Butt, Stephen Peter Shumack, Kurt Aaron Josef Gebauer, Lynda Jane Spelman, Shireen Kaur Sidhu, Michael George Freeman, Peter Anthony Foley, Lajos, Kemeny, Eva, Remenyik, Zsuzsanna, Karolyi, Marc, Bourcier, Wayne Douglas Carey, Victoria, Taraska, Derek, Haaland, Aditya Kumar Gupta, Catherine, Maari, Darryl Paul Toth, Michael, Sebastian, Sandra, Philipp, Roland, Kaufmann, Diamant, Thaci, Thomas Andreas Werfel, Leila, Parise, Ingo, Haase, Petra Staubach Renz, Shinichi, Imafuku, Juichiro, Nakayama, Tadashi, Terui, Hideki, Nakajima, Shigetoshi, Sano, Uncover, 2 Study Group, and Uncover, 3 Study Group
- Subjects
Adult ,Male ,medicine.medical_specialty ,Neutropenia ,Tildrakizumab ,Antibodies, Monoclonal, Humanized ,Placebo ,Severity of Illness Index ,Antibodies ,law.invention ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Candidiasis ,Female ,Humans ,Inflammatory Bowel Diseases ,Intention to Treat Analysis ,Middle Aged ,Psoriasis ,Medicine (all) ,Internal medicine ,Monoclonal ,Medicine ,Humanized ,Risankizumab ,Intention-to-treat analysis ,business.industry ,General Medicine ,Clinical trial ,Ixekizumab ,Guselkumab ,030220 oncology & carcinogenesis ,Physical therapy ,business - Abstract
BACKGROUND Two phase 3 trials (UNCOVER-2 and UNCOVER-3) showed that at 12 weeks of treatment, ixekizumab, a monoclonal antibody against interleukin-17A, was superior to placebo and etanercept in the treatment of moderate-to-severe psoriasis. We report the 60-week data from the UNCOVER-2 and UNCOVER-3 trials, as well as 12-week and 60-week data from a third phase 3 trial, UNCOVER-1. METHODS We randomly assigned 1296 patients in the UNCOVER-1 trial, 1224 patients in the UNCOVER-2 trial, and 1346 patients in the UNCOVER-3 trial to receive subcutaneous injections of placebo (placebo group), 80 mg of ixekizumab every 2 weeks after a starting dose of 160 mg (2-wk dosing group), or 80 mg of ixekizumab every 4 weeks after a starting dose of 160 mg (4-wk dosing group). Additional cohorts in the UNCOVER-2 and UNCOVER-3 trials were randomly assigned to receive 50 mg of etanercept twice weekly. At week 12 in the UNCOVER-3 trial, the patients entered a long-term extension period during which they received 80 mg of ixekizumab every 4 weeks through week 60; at week 12 in the UNCOVER-1 and UNCOVER-2 trials, the patients who had a response to ixekizumab (defined as a static Physicians Global Assessment [sPGA] score of 0 [clear] or 1 [minimal psoriasis]) were randomly reassigned to receive placebo, 80 mg of ixekizumab every 4 weeks, or 80 mg of ixekizumab every 12 weeks through week 60. Coprimary end points were the percentage of patients who had a score on the sPGA of 0 or 1 and a 75% or greater reduction from baseline in Psoriasis Area and Severity Index (PASI 75) at week 12. RESULTS In the UNCOVER-1 trial, at week 12, the patients had better responses to ixekizumab than to placebo; in the 2-wk dosing group, 81.8% had an sPGA score of 0 or 1 and 89.1% had a PASI 75 response; in the 4-wk dosing group, the respective rates were 76.4% and 82.6%; and in the placebo group, the rates were 3.2% and 3.9% (P
- Published
- 2016
3. Correction of the anion gap for albumin in order to detect occult tissue anions in shock
- Author
-
Mark Hatherill, Louis Reynolds, Langley R. Purves, Andrew C. Argent, and Zainab Waggie
- Subjects
medicine.medical_specialty ,Bicarbonate ,Serum albumin ,Metabolic alkalosis ,Anion gap ,Acid-Base Imbalance ,Protein-Energy Malnutrition ,Gastroenterology ,chemistry.chemical_compound ,Albumins ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Hypoalbuminemia ,Child ,Serum Albumin ,Acid-Base Equilibrium ,biology ,business.industry ,Liver Diseases ,Albumin ,Shock ,medicine.disease ,Surgery ,chemistry ,Pediatrics, Perinatology and Child Health ,Lactates ,biology.protein ,Original Article ,Acid–base reaction ,business ,Acid–base imbalance - Abstract
Background: It is believed that hypoalbuminaemia confounds interpretation of the anion gap (AG) unless corrected for serum albumin in critically ill children with shock. Aim: To compare the ability of the AG and the albumin corrected anion gap (CAG) to detect the presence of occult tissue anions. Methods: Prospective observational study in children with shock in a 22 bed multidisciplinary paediatric intensive care unit of a university childrenrsquo;s hospital. Blood was sampled at admission and at 24 hours, for acid-base parameters, serum albumin, and electrolytes. Occult tissue anions (lactate + truly “unmeasured” anions) were calculated from the strong ion gap. The anion gap ((Na + K) − (Cl + bicarbonate)) was corrected for serum albumin using the equation of Figge: AG + (0.25 × (44 − albumin)). Occult tissue anions (TA) predicted by the anion gap were calculated by (anion gap − 15 mEq/l). Optimal cut off values of anion gap were compared by means of receiver operating characteristic (ROC) curves. Ninety three sets of data from 55 children (median age 7 months, median weight 4.9 kg) were analysed. Data are expressed as mean (SD), and mean bias (limits of agreement). Results: The incidence of hypoalbuminaemia was 76% (n = 42/55). Mean serum albumin was 25 g/l (SD 8). Mean AG was 15.0 mEq/l (SD 6.1), compared to the CAG of 19.9 mEq/l (SD 6.6). Mean TA was 10.2 mmol/l (SD 6.3). The AG underestimated TA with mean bias 10.2 mmol/l (4.1–16.1), compared to the CAG, mean bias 5.3 mmol/l (0.4–10.2). A clinically significant increase of TA >5 mmol/l was present in 83% (n = 77/93) of samples, of which the AG detected 48% (n = 36/77), and the CAG 87% (n = 67/77). Post hoc ROC analysis revealed optimal cut off values for detection of TA >5 mmol/l to be AG >10 mEq/l, and CAG >15.5 mEq/l. Conclusion: Hypoalbuminaemia is common in critically ill children with shock, and is associated with a low observed anion gap that may fail to detect clinically significant amounts of lactate and other occult tissue anions. We suggest that the albumin corrected anion gap should be calculated to screen for occult tissue anions in these children.
- Published
- 2002
4. Tohoku-Oki earthquake caused major ionospheric disturbances at 450 km altitude over Alaska
- Author
-
Yang, Y., Meng, X., Komjathy, A., Verkholyadova, O., Langley, R., Tsurutani, B., and Mannucci, A.
- Published
- 2014
5. ROLE OF TUMOR NECROSIS FACTOR AND INTERFERON GAMMA IN ENDOTOXIN-INDUCED E-SELECTIN EXPRESSION
- Author
-
Mary E. Gerritsen, James A. Russell, Michael J. Eppihimer, D. N. Granger, and Langley R
- Subjects
Lipopolysaccharides ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Inflammation ,Critical Care and Intensive Care Medicine ,Proinflammatory cytokine ,Interferon-gamma ,Mice ,Internal medicine ,Intestine, Small ,E-selectin ,Gene expression ,Escherichia coli ,medicine ,Animals ,Interferon gamma ,Intestine, Large ,Lung ,biology ,Tumor Necrosis Factor-alpha ,Antibodies, Monoclonal ,Shock, Septic ,Mice, Mutant Strains ,Small intestine ,Mice, Inbred C57BL ,Endocrinology ,Cytokine ,medicine.anatomical_structure ,Gastric Mucosa ,Organ Specificity ,Emergency Medicine ,biology.protein ,Tumor necrosis factor alpha ,Endothelium, Vascular ,medicine.symptom ,E-Selectin ,medicine.drug - Abstract
Tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), potent inflammatory cytokines, are released by macrophages during endotoxin shock. However, the contribution of these cytokines to endotoxin-induced inflammation has not been defined. The expression of E-selectin, measured using the dual radiolabeled monoclonal antibody (mAb) technique, was monitored in different tissues of endotoxin-challenged wild-type and IFN-gamma-deficient mice receiving a mAb to TNF-alpha (TN3). A significant elevation in E-selectin expression occurred in all tissues of wild-type mice challenged with endotoxin. Injection of TN3 in wild-type mice significantly attenuated the endotoxin-induced up-regulation of E-selectin in all tissues (p < .05) except the pancreas. The level of reduction in endotoxin-induced E-selectin expression ranged between 30% in the stomach to 60% in the small intestine. E-selectin expression in endotoxin-challenged, IFN-gamma-deficient mice was significantly reduced in the small and large intestines, when compared with endotoxin-challenged wild-type mice. Although IFN-gamma deficiency had no effect on E-selectin expression in other tissues, administration of TN3 to endotoxin-challenged, IFN-gamma-deficient mice significantly reduced E-selectin expression to levels observed in endotoxin-challenged, wild-type mice that received TN3. These findings indicate that TNF-alpha is essential for achievement of maximal E-selectin expression in most vascular beds during endotoxemia, whereas the contribution of IFN-gamma is largely confined to the small intestine.
- Published
- 1999
6. Management of R&D program evaluations: A case study of Canada's energy R&D program
- Author
-
Douglas Williams and Langley R Muir
- Subjects
Program evaluation ,Government ,business.industry ,Publishing ,Energy (esotericism) ,Accounting ,Successful completion ,Library and Information Sciences ,Public relations ,Investment (macroeconomics) ,business ,Education - Abstract
A large and complex evaluation of a Can$1.3 billion energy R&D program was recently carried out for the Canadian government. The challenges included a controversial and complex program, multiple stakeholders with very diverse interests, a large investment, an atmosphere of suspicion and mistrust and very tight deadlines. The methods used in the management of the study and which led to its successful completion are applicable to similar large-scale evaluation situations. Copyright , Beech Tree Publishing.
- Published
- 1994
7. Mechanism of iron release from human serum C-terminal monoferric transferrin to pyrophosphate: kinetic discrimination between alternative mechanisms
- Author
-
Langley R. Purves, David C. Ross, Paul A. Adams, and Timothy J. Egan
- Subjects
Arrhenius equation ,chemistry.chemical_classification ,Reaction mechanism ,Stereochemistry ,Kinetics ,Pyrophosphate ,Inorganic Chemistry ,symbols.namesake ,chemistry.chemical_compound ,Reaction rate constant ,chemistry ,Transferrin ,symbols ,Metalloprotein ,Physical and Theoretical Chemistry ,Saturation (chemistry) ,Nuclear chemistry - Abstract
The kinetics of iron release from C-terminal monoferric transferrin (Fe C Tf) to pyrophosphate (PP) under pseudo-first-order conditions show an apparent saturation linear dependence of k obs on [PP]. The variation of k obs with [PP] was studied under conditions of variable temperature and added anion (X) concentration (Cl - , ClO 4 - , NO 3 - , SO 4 2- , HPO 4 2- )
- Published
- 1992
8. A compact internal tri-band antenna for mobile handsets
- Author
-
Tzortzakakis, Michail and Langley, R. J.
- Subjects
antenna ,mobile phone antenna ,monopole antenna ,helical antenna ,multi-band antenna - Abstract
A novel, compact and low profile internal antenna capable of operating in multiple bands is proposed. It consists of a long monopole ring, which is top-loaded by a helical element in order to produce two main resonances of wide bandwidth. Its compact size of length 10 mm, width 28 mm and height of 6 mm and small volume of 1.68 cm3, makes it possible to be used internally, inside the mobile phone. With the help of a small matching circuit a VSWR < 3 is achieved covering the bands of GSM900 (880-960 MHz), DCS (1710-1880 MHz) and PCS (1850-1990 MHz). The efficiency is above 50% in all bands. The Specific Absorption Rate (SAR) is also measured, presented and discussed in this article.
- Published
- 2005
9. Mortality and the nature of metabolic acidosis in children with shock
- Author
-
Mark Hatherill, Zainab Waggie, Louis Reynolds, Langley R. Purves, and Andrew C. Argent
- Subjects
medicine.medical_specialty ,Critical Care and Intensive Care Medicine ,Intensive Care Units, Pediatric ,Severity of Illness Index ,law.invention ,Hospitals, University ,South Africa ,Chlorides ,law ,Predictive Value of Tests ,Internal medicine ,medicine ,Humans ,Hospital Mortality ,Lactic Acid ,Prospective Studies ,Child ,Survival analysis ,Acid-Base Equilibrium ,Likelihood Functions ,business.industry ,Incidence ,Metabolic disorder ,Infant ,Metabolic acidosis ,Shock ,Hydrogen-Ion Concentration ,medicine.disease ,Hospitals, Pediatric ,Prognosis ,Intensive care unit ,Survival Analysis ,Surgery ,Standardized mortality ratio ,Predictive value of tests ,Shock (circulatory) ,Cardiology ,Base excess ,medicine.symptom ,Blood Gas Analysis ,Morbidity ,business ,Acidosis - Abstract
Mortality in children with shock is more closely related to the nature, rather than the magnitude (base deficit/excess), of a metabolic acidosis. To examine the relationship between base excess (BE), hyperlactataemia, hyperchloraemia, 'unmeasured' strong anions, and mortality. Prospective observational study set in a multi-disciplinary Paediatric Intensive Care Unit (PICU). Forty-six children, median age 6 months (1.5–14.4), median weight 5 kg (3.2–8.8), admitted to PICU with shock. Predicted mortality was calculated from the paediatric index of mortality (PIM) score. The pH, base excess, serum lactate, corrected chloride, and 'unmeasured' strong anions (Strong Ion Gap) were measured or calculated at admission and 24 h. Observed mortality (n=16) was 35%, with a standardised mortality ratio (SMR) of 1.03 (95% CI 0.71–1.35). There was no significant difference in admission pH or BE between survivors and nonsurvivors. There was no association between elevation of 'unmeasured' anions and mortality, although there was a trend towards hyperchloraemia in survivors (P=0.08). Admission lactate was higher in nonsurvivors (median 11.6 vs 3.3 mmol/l; P=0.0003). Area under the mortality receiver operating characteristic curve for lactate was 0.83 (955 CI 0.70–0.95), compared to 0.71 (95% CI 0.53–0.88) for the PIM score. Admission lactate level >5 mmol/l had maximum diagnostic efficiency for mortality, with a likelihood ratio of 2.0. There is no association between the magnitude of metabolic acidosis, quantified by the base excess, and mortality in children with shock. Hyperlactataemia, but not elevation of 'unmeasured' anions, is predictive of a poor outcome.
- Published
- 2003
10. Acetylcholinesterase of human intestinal tissue affected by Hirschsprung's disease: effect of magnesium chloride on isoforms
- Author
-
Samuel W. Moore, Langley R. Purves, and Glynis Johnson
- Subjects
Gene isoform ,Erythrocytes ,Aché ,Colon ,Clinical Biochemistry ,Magnesium Chloride ,Biology ,In Vitro Techniques ,Torpedo ,Biochemistry ,Isozyme ,chemistry.chemical_compound ,Mole ,medicine ,Centrifugation, Density Gradient ,Animals ,Humans ,Hirschsprung Disease ,chemistry.chemical_classification ,Differential centrifugation ,Histocytochemistry ,Nervous tissue ,Biochemistry (medical) ,General Medicine ,Hydrogen-Ion Concentration ,Acetylcholinesterase ,language.human_language ,Rats ,Intestines ,Isoenzymes ,Enzyme ,medicine.anatomical_structure ,chemistry ,language ,Cholinesterase Inhibitors - Abstract
Acetylcholinesterase (AChE) molecular isoforms from aganglionic and adjacent unaffected (control) colonic tissue in patients with Hirschsprung's disease (HD) were analysed by density gradient centrifugation in order to determine the major AChE isoforms and the effect of a reported MgCl 2 inactivation assay method upon them, with a view to improving the AChE assay used in the diagnosis of Hirschsprung's disease. The total AChE level was greater in the HD-affected colonic tissue than the control tissue (HD: 9.0 vs. control: 7.3 units/g tissue) and this was due to a consistently greater elevation of the globular tetrameric form, G4 (HD: 48.8% vs. control: 35.5% of total AChE). The inactivation of whole tissue homogenates by brief exposure to 4 mol/l MgCl 2 followed the same pattern (HD: 48.4% vs. control: 28.7% inactivation). The detergent-extractable G4 is inhibited to a greater extent than the low salt-soluble G4 by exposure to 4 mol/l MgCl 2 (83.8% vs. 51.1%). These results imply that the elevated AChE levels in HD are mainly due to increases of the hydrophobic globular tetrameric form of AChE of the same type that is found in differentiating nervous tissue before synapse formation. The monomeric globular isoform G1 is not inhibited but the asymmetric A4, A8 and A12 isoforms are completely inhibited by exposure to 4 mol/l MgCl 2 . All isoforms of Torpedo (electric ray) electroplax and human erythrocyte AChE, mainly amphiphilic G2, are almost completely inhibited. The inhibition by 4 mol/l MgCl 2 of the main G4 isoform in HD-affected intestine accentuates the difference between aganglionic and unaffected intestine in fractionated samples, but does not provide a sufficiently specific G4 isoform assay. The use of 2–4 mol/l MgCl 2 in histochemical AChE staining reduces the activity slightly but does not differentiate the tetrameric AChE isoform that is increased in Hirschsprung's disease but does reduce contaminating erythrocyte AChE levels that can obscure the result in blood-stained biopsies. A specific immunochemical stain for hydrophobic AChE tetramers or the associated 20 kDa membrane associated subunit is therefore needed to provide specificity.
- Published
- 1995
11. Zinc binding by fibrin facilitates proteolysis by a snake (puffadder) venom protease
- Author
-
Dhesigen P. Naidoo and Langley R. Purves
- Subjects
Proteolysis ,medicine.medical_treatment ,Molecular Sequence Data ,chemistry.chemical_element ,Peptide ,Zinc ,Plasma protein binding ,Viper Venoms ,Fibrin ,Fibrin Fibrinogen Degradation Products ,Endopeptidases ,medicine ,Amino Acid Sequence ,Peptide sequence ,chemistry.chemical_classification ,Protease ,medicine.diagnostic_test ,biology ,Hematology ,Enzyme ,chemistry ,Biochemistry ,biology.protein ,Cardiology and Cardiovascular Medicine ,Protein Binding - Abstract
PAV protease is able to cleave between the crosslinked sites of the gamma-chain of fibrin and fibrin-derived D-dimer. The rate of digestion can be increased fourfold to tenfold by the addition of zinc ions. Although the PAV protease is a zinc-containing metalloenzyme, the enhanced rate of cleavage can be shown to be due to histidine-specific zinc binding by D-dimer. It is proposed that zinc ions cause a distortion of the inter-crosslink peptide chain, creating a novel protease-susceptible site. The physiologic relevance is uncertain due to the relatively low measured zinc binding constant Kd = 10(-3.88) M. Zinc binding could, nevertheless, create a useful fibrin-specific neoepitope for antibody recognition in vitro.
- Published
- 1992
12. Stabilization of the plasmin digestion products of fibrinogen and fibrin by calcium ions
- Author
-
J. Franks, G. Brown, Langley R. Purves, and G.G. Lindsey
- Subjects
Calcium metabolism ,Time Factors ,biology ,Plasmin ,chemistry.chemical_element ,Hematology ,Calcium ,Fibrinogen ,Fibrin ,Fibrin Fibrinogen Degradation Products ,chemistry ,Biochemistry ,medicine ,Biophysics ,biology.protein ,Humans ,Electrophoresis, Polyacrylamide Gel ,Chelation ,Fibrinolysin ,Ultracentrifuge ,Egtazic Acid ,Ultracentrifugation ,Polyacrylamide gel electrophoresis ,medicine.drug - Abstract
The role of calcium in the stabilization of fibrinogen and fibrin plasmin digestion products, D-monomer and D-dimer has been studied. The largest D fragment, D1 ∗ , and D-dimer are both stable to further plasmin degradation in the presence of calcium ions. Chelation of calcium leads to further plasmin digestion due to sequential cleavage of peptides from the C-terminal end of the γ-chain. This stabilization is due to calcium ions and not to occupation of the cross-link site. All the digestion products of D-dimer were also found to be stabilized by the re-addition of calcium ions.
- Published
- 1978
13. Variability of environmental loads
- Author
-
Val Swail, Langley R. Muir, and Marc A. Maes
- Subjects
East coast ,Environmental Engineering ,Oceanography ,Drag ,Environmental science ,Ocean Engineering ,Beaufort sea ,West coast ,Selection (genetic algorithm) - Abstract
The oceanographic and meteorological data bases presently available at the Canadian Climate Centre, Environment Canada are used to produce plots for the coefficient of variation of annual and monthly environmental loads due to winds and waves. This parameter is extremely important for the calculation of design risks and is linked to the selection of the environmental load factors in design codes. Extreme wind loads and wave loads induced by both drag and inertia are examined for the East Coast, the West Coast and the Beaufort Sea areas of Canada.
- Published
- 1988
14. The reconstitution of histone H3 H4 tetramer from acid extracted histones in the absence of urea
- Author
-
Patricia Thompson, George G. Lindsey, Langley R. Purves, and Claus von Holt
- Subjects
Chemical Phenomena ,Macromolecular Substances ,Biophysics ,Fractionation ,Biochemistry ,Histones ,Reconstitution ,chemistry.chemical_compound ,Tetramer ,Structural Biology ,Genetics ,Animals ,Urea ,H3H4 tetramer ,Molecular Biology ,Chromatography ,biology ,Chemistry ,Cell Biology ,Phosphate ,Molecular Weight ,Histone ,(Chicken erythrocyte chromatin) ,Ionic strength ,Yield (chemistry) ,biology.protein ,Dialysis (biochemistry) - Abstract
Simple mixing of acid purified histones H3 and H4 in equimolar quantities at low ionic strength near pH 7 does not yield the tetramer but rather a high Mr aggregate. Dialysis of acid extracted total or core histones into 2 M NaCl 150 mM phosphate (pH 7.4) followed by fractionation of the histone complexes at lower ionic strength (150 mM NaCl) results in an H3H4 tetramer of a structure identical to that derived from salt-extracted histones. Dialysis of acid extracted total or core histones directly into the lower ionic strength buffer with subsequent fractionation, results in H3H4 tetramer of closely similar structure.
- Published
- 1982
15. Iron binding proteins of iron-absorbing rat intestinal mucosa
- Author
-
Peter Jacobs, Langley R. Purves, and Glynis Johnson
- Subjects
Male ,Iron ,Transferrin receptor ,Biology ,Intestinal absorption ,Intestinal mucosa ,Iron-Binding Proteins ,Intestine, Small ,medicine ,Animals ,Tissue Distribution ,Intestinal Mucosa ,chemistry.chemical_classification ,Transferrin ,Iron-binding proteins ,Iron Deficiencies ,General Medicine ,Iron deficiency ,Transferrin-Binding Proteins ,medicine.disease ,Small intestine ,Rats ,Ferritin ,medicine.anatomical_structure ,Intestinal Absorption ,chemistry ,Biochemistry ,Ferritins ,biology.protein ,Carrier Proteins ,Research Article - Abstract
The distribution and quantitation of the iron-binding proteins of rat small intestinal mucosa was studied, in iron-deficient and replete animals, to explore their role in the absorption of iron. Adsorption (mucosal uptake) of iron in in situ ligated loops of small intestinal mucosa was found to be uniform throughout the length of the small intestine whereas absorption (carcass uptake) showed a steep decreasing gradient from the duodenum to the ileum. The disrupted, in vivo labeled mucosal cells were fractionated by isopycnic centrifugation and transferrin and ferritin were quantitated by radioimmunoassay. Transferrin derived from mucosal cells was shown to have a higher affinity for the antibody than transferrin in serum. Of the transferrin present in the mucosal extract, only a portion could be accounted for by contamination from the serum; the proteolysis resistant and intrinsic transferrin may be mucosal cell specific. Transferrin was found in similar amounts in all regions of the small intestine, was not affected by iron loading but doubled in response to iron deficiency. Mucosal ferritin was found in greater amounts in the iron-absorbing areas of the intestine, increased in the duodenum of iron-loaded animals, and decreased in iron-deficient animals. The incorporation of newly absorbed radioiron into ferritin was only found in iron absorbing regions and was completely inhibited by colchicine and cytochalasin-B, suggesting that ferritin was loaded with iron at the point of iron absorption and that the process is associated with vesicle movement and not simple diffusion. Transferrin and ferritin-specific immunoabsorption and also gel filtration established that no other soluble iron binding proteins were involved in absorption.
- Published
- 1983
16. Iceberg cutting with a hot wire
- Author
-
P.H. Gammon, Langley R. Muir, and John Courtenay Lewis
- Subjects
Engineering ,Explosive material ,business.industry ,Flow (psychology) ,Full scale ,Context (language use) ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Iceberg ,Fracture (geology) ,General Earth and Planetary Sciences ,Tube (fluid conveyance) ,Electric power ,business ,Marine engineering - Abstract
The engineering feasibility of several potential methods for inducing the large scale fracture of icebergs has been investigated. These methods included conventional explosives and incendiaries, thermal fracture of ice, various sorts of directed beams (radiation, fluid or particles), injected pressurised fluid (both confined and unconfined) and cutting with an electrically heated wire. All methods required large quantities of materials and/or energy. Some methods, while technically and perhaps economically feasible, were unacceptable from an environmental viewpoint. It has been determined that the cutting of an iceberg with an electrically heated small diameter tube stands out as the most practical approach. The tube is heated with a DC current of several hundred amperes and simultaneously moderated with a flow of fluid to prevent burnout. The electric power requirements are manageable in the marine context (a few hundreds of kilowatts) and the equipment is fairly conventional; hence not overly difficult to obtain and configure. A field program carried out within the context of the present study has demonstrated the functionality of the hot wire cutting method. Based on the results of this program, the design for a fully operational full scale version of an iceberg cutting system has been outlined and is judged appropriate for serious consideration in developing iceberg management strategies for Canada's East Coast oilfields.
- Published
- 1988
17. Variability of temperature, salinity and tidally‐averaged density in the middle estuary of the St Lawrence
- Author
-
Langley R. Muir
- Subjects
Hydrology ,Salinity ,Atmospheric Science ,geography ,geography.geographical_feature_category ,Horizontal and vertical ,Temperature salinity diagrams ,Estuary ,Oceanography ,Linear combination ,Standard deviation ,Geology - Abstract
Surveys in the Middle Estuary of the St Lawrence have yielded a data base consisting of more than 15,000 T‐S pairs distributed over 62 13‐h profiling stations. Although the T‐S curves at each station are remarkably linear, the variability of the slopes and intercepts of the lines is considerable. The means and standard deviations of the temperature and salinity at each individual station are not explicable in terms of linear combinations of the parameters for location in the Estuary, the upstream water properties, the phase of the spring‐neap cycle and the tidal energies. It is shown that the tidally‐averaged density structure is separable into horizontal and vertical components and that its vertical variation over the whole Estuary may be explained by any one of three different functional forms. However, its horizontal variation is not explicable in terms of linear combinations of the parameters mentioned in the paragraph above. Plots of the horizontal variations in temperature, salinity or dens...
- Published
- 1981
18. On the calculation of extreme wave heights: A review
- Author
-
Langley R. Muir and A.H. El-Shaarawi
- Subjects
Environmental Engineering ,Goodness of fit ,Statistical assumption ,Computation ,Statistics ,Wave height ,Ocean Engineering ,Rogue wave ,Extreme value theory ,Confidence interval ,Statistical hypothesis testing ,Mathematics - Abstract
Over the past two decades there has been a great deal of interest in calculating design waves for offshore structures. This paper reviews the data limitations, statistical assumptions, distributions, fitting methods, and statistical tests used to determine confidence intervals and goodness of fit. Use is made of an illustrative example from the Grand Banks of Canada to indicate how a design wave could be calculated. It is concluded that no single method will be entirely suitable for all data sets.
- Published
- 1986
19. The arrival rate of severe storms off the east coast of Canada: Research note
- Author
-
Langley R. Muir and Marc A. Maes
- Subjects
Atmospheric Science ,East coast ,Meteorology ,Severe weather ,Storm ,Oceanography ,Poisson distribution ,Wind speed ,symbols.namesake ,Wave height ,symbols ,Probability distribution ,Extreme value theory ,Geology - Abstract
Modern structural analysis techniques are heavily dependent upon statistical methods. The determination of design loads involves the calculation of long‐return period environmental parameters such as the 100‐year wind speed or the 100‐year wave height. One way in which to do this is to use the theory of compound distributions rather than the usual extreme value theory. Of critical importance, however, is the determination of which probability distributions to use. It is shown in this paper that the arrival rate of storms on Canada's East Coast is Poisson distributed and, therefore, that compound distributions may be used to calculate long return‐period environmental parameters.
- Published
- 1988
20. Effect of fibrinogenolytic products D and E on fibrinogen and albumin synthesis in the rat
- Author
-
S J Saunders, L O Frith, P Mason, W T Franks, J A Franks, J J Franks, R E Kirsch, and Langley R. Purves
- Subjects
Serum albumin ,Fibrinogen ,Fibrin Fibrinogen Degradation Products ,Albumins ,medicine ,Animals ,Amino Acids ,Serum Albumin ,chemistry.chemical_classification ,Haptoglobins ,biology ,Haptoglobin ,Albumin ,General Medicine ,Peptide Fragments ,Rats ,Amino acid ,Secretory protein ,chemistry ,Biochemistry ,biology.protein ,Electrophoresis, Polyacrylamide Gel ,Research Article ,medicine.drug - Abstract
Previous studies are in conflict over the effect of infusing mixed fibrinogen-fibrin degradation products on fibrinogen synthesis, as determined by changes in fibrinogen concentration or by incorporation of labeled amino acids into fibrinogen. We have injected purified homologous fragments D1 and E into rats and measured their fibrinogen and albumin synthetic rates by the [14C]carbonate technique, a method that provides quantitative estimates of hepatic secretory protein synthesis. Fibrinogen fractional synthetic rates were increased 2.5 times in animals injected with fragment D1, compared with saline-injected controls. No increase were observed in fragment E-injected animals. Neither fragment produced changes in albumin synthesis. Fragment D increased plasma fibrinogen concentration, but did not raise plasma haptoglobin levels. These results suggest that fragment D is a regulator of fibrinogen synthesis.
- Published
- 1981
21. Vapor-Liquid Equilibria for Ethyl Alcohol Binary Systems
- Author
-
Matthew Van Winkle and Langley R. Hellwig
- Subjects
chemistry.chemical_compound ,Materials science ,chemistry ,Inorganic chemistry ,General Engineering ,Binary number ,Vapor liquid ,Alcohol - Published
- 1953
22. ALPHA-FETOPROTEIN AND THE DIAGNOSIS OF LIVER CELL CANCER
- Author
-
Langley R. Purves
- Subjects
Hepatitis ,Oncology ,medicine.medical_specialty ,business.industry ,Cancer ,Normal level ,Model system ,medicine.disease ,Liver cell cancer ,Internal medicine ,Immunology ,Medicine ,Stage (cooking) ,business ,Alpha-fetoprotein ,Subclinical infection - Abstract
SUMMARY The use of alpha-fetoprotein (AFP) in the diagnosis of liver cell cancer is invaluable; most cases can be accurately diagnosed or justification can be provided to pursue the diagnosis by other means. Whether or not the measurement of AFP is justified as an epidemiological tool is doubtful since there is a normal AFP level (the effects of subclinical hepatitis altering this normal level) and since liver cell cancer is, in general, not responsive to treatment. As a model system to demonstrate the possibilities of an early cancer detection system, the AFP test has exposed some interesting problems. Do all cancers grow to the clinical or sub-clinical stage as rapidly as liver cell cancer in southern Africa appears to do? Is the promotion of tumour growth really so dramatically triggered and is the initial transformation perhaps less significant in the time scale? Further prospective surveys using the quantitation which radioimmunoassay can provide are required, hopefully, to answer some of these questions before we can hope to intervene in the development of the early stages of the evolving cancer to the benefit of the patient.
- Published
- 1976
23. A One-Dimensional Tidal Model for Estuarine Networks
- Author
-
Langley R. Muir
- Subjects
Mathematical optimization ,Continuity equation ,Flow (mathematics) ,Computation ,Mathematical analysis ,Finite difference method ,Equations of motion ,Boundary value problem ,Solver ,Conservation of mass ,Mathematics - Abstract
Publisher Summary This chapter reviews one-dimensional numerical modeling of unsteady flow in networks of canals, rivers, and estuaries. The model allows the computation of water elevation and velocity in any network of open channels to which many assumptions are applicable, such as appropriate boundary conditions are available. Flow in open channels can be described by two equations, one, expressing the conservation of mass (the continuity equation) and second, expressing the conservation of momentum in the longitudinal direction (the momentum equation). This chapter develops all of the theory necessary to construct a numerical model for simulating unsteady flow conditions in networks of open channels. It presents a form1 method for describing the flow relationships in any network. The implicit finite difference method is then described and extended for use in networks. The equations of motion are given, with a description of a generalized equation solver, and the properties of the finite difference scheme are discussed.
- Published
- 1978
24. Identification of Internal Tides in Tidal Current Records from the Middle Estuary of The St. Lawrence
- Author
-
Langley R. Muir
- Subjects
geography ,geography.geographical_feature_category ,Phase (waves) ,Estuary ,Geophysics ,Tidal current ,Physics::Geophysics ,Harmonic analysis ,Oceanography ,Amplitude ,Barotropic fluid ,Harmonic ,Hindcast ,Astrophysics::Earth and Planetary Astrophysics ,Geology - Abstract
Observations of tidal currents are traditionally analysed by means of spectral analysis, to ensure that only tidal frequencies are present and by harmonic analysis, to obtain the amplitude and phases of the tidal constituents and to allow the prediction of future currents. When this was done for a series of records obtained in the St. Lawrence it was found that 95% of the energy was at the tidal frequencies, and that the calculated “tidal constituents” allowed hindcasting the tidal currents with great accuracy. However, neither the amplitudes nor the phases of the “tidal constituents” could be interpreted as standing or progressive waves over the whole Estuary and these amplitudes and phases seemed to be entirely uncorrelated, even though the observations were separated by re1 atively short distances when compared to the expected wave lengths of the barotropic waves. The topography and density field of the Estuary allow the The topography and density field of the Estuary allow the generation and propagation of internal gravity waves at the same frequencies as the barotropic tides but with much shorter wave lengths. These internal tides may interfere linearly with the barotropic tidal currents, causing phase and ampitude variations, depending upon the location in the Estuary and the density field in the Estuary. By means of admittance calculations on very short portions of the observed currents records, it is possible to show that the amplitudes and phases of the “tidal constituents” obtained from the harmonic analyses vary in a way that would be expected if both barotropic and internal tides were present in the Estuary.
- Published
- 1982
25. The carbohydrate prosthetic groups of rat fibrinogen plasmic fragment E
- Author
-
E.H. Merrifield, George G. Lindsey, Langley R. Purves, and G. Brown
- Subjects
Glycosylamine ,chemistry.chemical_classification ,Carbohydrates ,Mannose ,Fibrinogen ,Oligosaccharides ,Oligosaccharide ,Carbohydrate ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Peptide Fragments ,Sialic acid ,Rats ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Affinity chromatography ,Glucosamine ,Galactose ,Animals ,Fibrinolysin - Abstract
Rat fibrinogen plasmic fragment E was found to contain one oligosaccharide chain per gamma-chain attached by a glycosylamine linkage. The oligosaccharide was composed of 1 sialic acid, 1 galactose, 2 mannose and 2 glucosamine residues. The probable sequence from the nonreducing end was sialic acid leads to galactose beta leads to mannose alpha leads to mannose alpha leads to glucosamine leads to glucosamine. No difference in the rate of clearance from the rat circulation could be detected between native and desialated fragment E. A non-denaturing method for the purification of fragment E is described.
- Published
- 1979
26. The effects of cytoskeletal inhibitors on intestinal iron absorption in the rat
- Author
-
Glynis Johnson, Langley R. Purves, and Peter Jacobs
- Subjects
Male ,Cytochalasin B ,Iron ,Biophysics ,Absorption (skin) ,In Vitro Techniques ,Biochemistry ,chemistry.chemical_compound ,In vivo ,medicine ,Centrifugation, Density Gradient ,Animals ,Transcellular ,Cytoskeleton ,Molecular Biology ,chemistry.chemical_classification ,biology ,Small intestine ,Rats ,Ferritin ,medicine.anatomical_structure ,chemistry ,Intestinal Absorption ,Transferrin ,Vincristine ,Ferritins ,biology.protein ,Colchicine - Abstract
An established and validated method using loops of intestine in vivo in rats was used to study the effects of cytoskeletal inhibitors on iron absorption. Radioactive iron instilled into the loop of intestine pretreated with test substance was monitored in the blood and, after death, ferritin loading radioactive iron was measured on density gradients of mucosal cell homogenates and absorbed iron in the carcass was determined. Colchicine, vincristine and cytochalasin B all caused dose- and time-dependent inhibition of iron absorption, and the effects of cytochalasin B were reversible within 1 h. It is not known which cellular component is the vehicle for the transcellular movement of iron from the intestinal lumen onto plasma transferrin; however, this study showed that the uptake of iron by ferritin in an iron-absorbing loop of intestine paralleled the actual absorption of iron into the carcass. This phenomenon did not occur in non-iron-absorbing intestinal and was inhibited by the action of the cytoskeletal inhibitors in the iron-absorbing region. Previously we had shown that iron uptake into cells and onto cellular transferrin was virtually the same throughout the small intestine, irrespective of the iron-absorbing capacity of the region. The results of this study therefore suggest that iron absorption depends on an intact cytoskeletal system and that ferritin in the iron-absorbing cell is able to load from the pool of iron committed to transcellular movement onto plasma transferrin.
- Published
- 1985
27. Octamer reconstitution from acid-extracted chicken erythrocyte histones
- Author
-
Patricia Thompson, Linda Pretorius, Claus von Holt, George G. Lindsey, and Langley R. Purves
- Subjects
Circular dichroism ,Chromatography ,Erythrocytes ,biology ,Spectrum Analysis ,Biophysics ,Cell Biology ,Hydrogen-Ion Concentration ,Biochemistry ,Fluorescence spectroscopy ,Histones ,Histone ,Biopolymers ,Molecular size ,Structural Biology ,Histone Octamer Reconstitution ,Genetics ,biology.protein ,Animals ,Histone octamer ,Molecular Biology ,Chickens - Abstract
Histone octamers have been reconstituted from acid-extracted chicken erythrocyte histones. By the criteria of molecular size on exclusion chromatography as well as sedimentation velocity and conformational properties established by circular dichroism, fluorescence spectroscopy and imido-ester cross-linking, the reconstituted octamers have a structure identical to that of salt-extracted octamers.
- Published
- 1983
28. Sites of D-domain interaction in fibrin-derived D dimer
- Author
-
Langley R. Purves, George G. Lindsey, and John J. Franks
- Subjects
Plasmin ,Macromolecular Substances ,Peptide ,Biochemistry ,Fibrin ,Antibodies ,Epitopes ,Drug Stability ,medicine ,Molecule ,Animals ,Humans ,Fibrinolysin ,chemistry.chemical_classification ,biology ,Chemistry ,Immune Sera ,Fibrinogen ,Fluorescence ,Crystallography ,Cross-Linking Reagents ,Spectrometry, Fluorescence ,Polymerization ,Covalent bond ,biology.protein ,Rabbits ,Fluorescence anisotropy ,medicine.drug - Abstract
We have examined the plasmic digestion products of fibrin formed in the presence of dansylcadaverine, the fluorescent D dimer, to determine whether they are held together not only by the cross-link region on the gamma chain but also by other interactions on the D domain. Antibodies to the D dimer reacted 8X more strongly with sites on the D dimer (purified or in the presence of E) than with sites on fibrinogen or plasmin-digested fibrinogen. The reactivity of this surface site was lost when the gamma chain was cleaved by plasmin after the molecule had been destabilized by the removal of calcium ions, thus breaking the covalent linkage of the homodimer. The noncovalent D dimer retained its dimeric structure by the criteria of molar volume, measured by fluorescence polarization, and molecular sieving. The noncovalently attached, cross-link-containing peptide bound tightly to the parent molecules at higher temperatures but rotated more freely below 15 degrees C, and could be lost from the parent molecules without destroying the dimeric structure. We therefore propose that the forces maintaining the dimeric structure of the noncovalently joined molecule are not solely located at the gamma-chain cross-link region. These other sites on the D domain are therefore candidates for the initial fibrinogen polymerization site and may also have a role in fibrinogen half-molecule assembly.
- Published
- 1980
29. Cleavage of fibrin-derived D-dimer into monomers by endopeptidase from puff adder venom (Bitis arietans) acting at cross-linked sites of the gamma-chain. Sequence of carboxy-terminal cyanogen bromide gamma-chain fragments
- Author
-
Maud Purves, Langley R. Purves, and Wolf F. Brandt
- Subjects
chemistry.chemical_classification ,Fibrin ,Dipeptide ,Autoanalysis ,Edman degradation ,Chemistry ,Plasmin ,Macromolecular Substances ,Peptide ,Viper Venoms ,Biochemistry ,Endopeptidase ,chemistry.chemical_compound ,medicine ,Cyanogen bromide ,Amino Acid Sequence ,Cyanogen Bromide ,Peptide sequence ,Histidine ,Chromatography, High Pressure Liquid ,medicine.drug ,Peptide Hydrolases - Abstract
Puff adder venom contains a protease capable of cleaving the gamma-chain of cross-linked D-dimer, derived from the plasmin digestion of fibrin, into apparently symmetrical monomers. The cross-linked gamma-chains are separated in the process without apparent loss of mass and without loss of the substituent at the glutamine cross-link site, if fluorescent D-dimer (the lysine analogue dansylcadaverine used as substituent) is used as substrate [Purves, L. R., Purves, M., Lindsey, G. G., & Linton, N. J. (1986) S. Afr. J. Sci. 82, 30]. The gamma-chain from puff adder venom digested D-monomer was isolated and cleaved by cyanogen bromide, and the carboxy-terminal peptide was isolated and sequenced. The carboxy-terminal peptide composition indicated a lower content of histidine, leucine, and glycine than expected. Manual microsequencing by gas-phase Edman degradation demonstrated that two amino-terminal ends were present. By use of the known sequence of the human fibrinogen gamma-chain, the sequencing data could be resolved into a dipeptide cross-linked between lysine-406 and either glutamine-398 or -399 (residues 6 and 13 or 14 from the carboxy-terminal end of the gamma-chain) with the loss of residues 401-404 that occur between the cross-link sites of both antiparallel cross-linked gamma-chains. D-dimer is therefore separated into monomers by cleavage of the gamma-chain between the cross-link sites. Two symmetrical fragments are produced consisting of a cross-linked dipeptide with the loss of four amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1987
30. Effect of gradients in the GPS estimation of tropospheric water vapor
- Author
-
Coster, A. J., Niell, A. E., Solheim, F. S., Virgilio Mendes, Toor, P. C., and Langley, R. B.
31. Effects of magnetic geometry, fluctuations, and electric fields on confinement in the Advanced Toroidal Facility
- Author
-
Isler, R. C., Aceto, S., Baylor, L. R., Bigelow, T. S., Bell, G. L., Bell, J. D., Carreras, B. A., Colchin, R. J., Crume, E. C., Dominguez, N., Dory, R. A., Dunlap, J. L., Dyer, G. R., England, A. C., Gandy, R. F., Glowienka, J. C., Hanson, G. R., Harris, J. H., Hiroe, S., Horton, L. D., Jernigan, T. C., Ji, H., Langley, R. A., Lee, D. K., Likin, K. M., Lyon, J. F., Ma, C. H., Morimoto, S., Murakami, M., Okada, H., Qualls, A. L., Rasmussen, D. A., Rome, J. A., Sato, M., Schwelberger, J. G., Michael Shats, Simpkins, J. E., Thomas, C. E., Uckan, T., Wade, M. R., Wilgen, J. B., Wing, W. R., Yamada, H., and Zielinski, J. J.
32. Fluctuation and modulation transport studies in the Advanced Toroidal Facility (ATF) torsatron
- Author
-
Wilgen, J. B., Murakami, M., Harris, J. H., Bigelow, T. S., Dory, R. A., Carreras, B. A., Aceto, S. C., Batchelor, D. B., Baylor, L. R., Bell, G. L., Bell, J. D., Colchin, R. J., Crume, E. C., Dominguez, N., Dunlap, J. L., Dyer, G. R., England, A. C., Gandy, R. F., Glowienka, J. C., Goldfinger, R. C., Goulding, R. H., Hanson, G. R., Hidalgo, C., Hiroe, S., Hirshman, S. P., Horton, L. D., Howe, H. C., Hutchinson, D. P., Ralph Isler, Jernigan, T. C., Ji, H., Kaneko, H., Kovrizhnykh, L. M., Kwon, M., Langley, R. A., Lee, D. K., Likin, K. M., Lyon, J. F., Ma, C. H., Menon, M. M., Mioduszewski, P. K., Motojima, O., Okada, H., Paul, S., Qualls, A. L., Rasmussen, D. A., Richards, R. K., Rome, J. A., Saltmarsh, M. J., Sarksyan, K. A., Sato, M., Schwelberger, J. G., Shaing, K. C., Shats, M. G., Shepard, T. D., Simpkins, J. E., Thomas, C. E., Uckan, T., Vander Sluis, K. L., Wade, M. R., Wing, W. R., Yamada, H., and Zielinski, J. J.
33. Comparison of measurements of atmospheric wet delay by radiosonde, water vapor radiometer, GPS, and VLBI
- Author
-
Niell, A. E., Coster, A. J., Solheim, F. S., Virgilio Mendes, Toor, P. C., Langley, R. B., and Upham, C. A.
34. Initial modelling and controller design for active control of spacecraft microvibrations
- Author
-
Aglietti, G. S., Gabriel, S. B., Langley, R. S., and Eric Rogers
35. Non-Gaussian discriminative factor models via the max-margin rank-likelihood
- Author
-
Xin Yuan, Henao, R., Tsalik, E. L., Langley, R. J., and Carin, L.
- Subjects
FOS: Computer and information sciences ,ComputingMethodologies_PATTERNRECOGNITION ,Statistics - Machine Learning ,Machine Learning (stat.ML) - Abstract
We consider the problem of discriminative factor analysis for data that are in general non-Gaussian. A Bayesian model based on the ranks of the data is proposed. We first introduce a new {\em max-margin} version of the rank-likelihood. A discriminative factor model is then developed, integrating the max-margin rank-likelihood and (linear) Bayesian support vector machines, which are also built on the max-margin principle. The discriminative factor model is further extended to the {\em nonlinear} case through mixtures of local linear classifiers, via Dirichlet processes. Fully local conjugacy of the model yields efficient inference with both Markov Chain Monte Carlo and variational Bayes approaches. Extensive experiments on benchmark and real data demonstrate superior performance of the proposed model and its potential for applications in computational biology., Comment: 14 pages, 7 figures, ICML 2015
36. Nonlinear statistical energy analysis modelling of a complex structural-acoustic system
- Author
-
Luis Andrade, Langley, R., Butlin, T., Brett, M., and Nielsen, O.
37. Bayesian identification of uncertain parameters in hybrid vibro-acoustic models
- Author
-
Edwin Reynders, Simoen, E., Lombaert, G., Legault, J., and Langley, R. S.
38. On the response distribution of nonparametric probabilistic models for mid- and high-frequency analysis
- Author
-
Edwin Reynders, Legault, J., and Langley, R. S.
39. Improved mapping functions for atmospheric refraction correction in SLR
- Author
-
Virgilio Mendes, Prates, G., Pavlis, E. C., Pavlis, D. E., and Langley, R. B.
- Subjects
Air ,Index - Abstract
[1] We present two new mapping functions (MFs) to model the elevation angle dependence of the atmospheric delay for satellite laser ranging (SLR) data analysis. The new MFs were derived from ray tracing through a set of data from 180 radiosonde stations globally distributed, for the year 1999, and are valid for elevation angles above 3degrees. When compared against ray tracing of two independent years of radiosonde data (1997-1998) for the same set of stations, our MFs reveal submillimetre accuracy for elevation angles above 10degrees, representing a significant improvement over other MFs, and is confirmed in improved solutions of LAGEOS and LAGEOS 2 data analysis. info:eu-repo/semantics/publishedVersion
40. Elastic dipole antenna prepared with thin metal films on elastomeric substrate
- Author
-
Liu, Q., Robinson, A. P., Ford, K. L., Langley, R. J., and Lacour, S. P.
- Abstract
The manufacture and characterisation of an elastic dipole antenna that is reversibly deformable and stretchable is described. The metallisation technique of depositing sub-micron-thick gold (Au) film on pillar patterned elastomer polydimethylsiloxane has been developed for elastic antenna applications. Under strain, the gold films may be stretched to 20% elongation, hundreds of thousands of times with reasonable electrical conduction. The dipole antenna based on this technique can withstand 10% strain and return to its original state after removal of the applied stretch.
41. Performance Evaluation of Integrated GPS/GIOVE Precise Point Positioning
- Author
-
Cao, W., Hauschild, A., Steigenberger, P., Langley, R. B., Urquhart, L., Santos, M., and Oliver Montenbruck
- Subjects
Real-Time Clock Estimation GPS GIOVE Precise Point Positioning
42. Alefacept-induced decreases in circulating blood lymphocyte counts correlate with clinical response in patients with chronic plaque psoriasis
- Author
-
Ortonne, J. -P, Lebwohl, M., Em Griffiths, C., Barber, K., Murray, E., Bourcier, M., Gulliver, W., Langley, R., Guenther, L., Papp, K., Tan, J., Poulin, Y., Heenen, M., Lambert, J., La Brassine, M., Kragballe, K., Grönhöj-Larsen, F., Humbert, P., Guillet, G., Thomas, P., Schmutz, J. -L, Dubertret, L., Lorette, G., Sterry, W., Altmeyer, P., Wozel, G., Christophers, E., Mahrle, G., Haustein, U. -F, Plewig, G., Luger, T., Leicha, M., Aragües, M., Aliaga, A., Bos, J. D., Kerkhof, P., Oranje, A., Ferguson, J., Rhodes, L., Jonathan Barker, Stough, D., Hamlin, R., Smith, S., Drehobl, M., Lowe, N., Brown, R., Nelson, C., Aton, J., Ling, M., Gordon, K., Belsito, D., Stewart, D., Leonardi, C., Heffernan, M., Casale, T., Hassman, D., Baker, D., Roberts, J., Farber, H., Frankel, E., Loven, K., Sander, H., Hino, P., Gonzalez, J., and Nigra, T.
43. The Aspirin Foundation Scientific Conference: the history, the present state and the future of aspirin prophylaxis
- Author
-
Smith, T., Peter Elwood, Keating, C., Rothwell, P., Detering, E., Freedman, A., Langley, R., Logan, R., Phillips, C., and Decensi, A.
- Subjects
aspirin prophylaxis ,treatment ,cancer ,Conference Report ,vascular disease ,history ,cost-effectiveness - Abstract
The 2013 Aspirin Foundation Conference covered a range of topics from clinical and medical history, epidemiology, health economics, and the current uses of aspirin in general practice and in the treatment and prevention of cancer. The use of aspirin as primary prevention in people at risk of atherosclerotic events is now well known, but its use as a preventative agent in some cancer types is still under discussion, and data on colorectal and lung cancer were presented at this meeting. The potential use of aspirin in preventing vascular disease in HIV patients was also discussed. The cost effectiveness of aspirin as a primary prevention strategy was discussed for the first time in this series of meetings.
44. Tropospheric zenith delay prediction accuracy for high-precision GPS positioning and navigation
- Author
-
Virgilio Mendes and Langley, R. B.
45. Model verification for active control of microvibrations
- Author
-
Guglielmo Aglietti, Langley, R. S., Rogers, E., and Gabriel, S. B.
46. Westford water vapor experiment: Use of GPS to determine total precipitable water vapor
- Author
-
Coster, A. J., Niell, A. E., Solheim, F. S., Virgilio Mendes, Toor, P. C., Langley, R. B., and Ruggles, C. A.
47. Flexible dipole and monopole antennas
- Author
-
Qing, L., Kenneth Ford, Langley, R., Robinson, A., and Lacour, S.
48. ‘What Course Should You Steer?’
- Author
-
Langley R. Muir
- Subjects
Beam (nautical) ,Algebraic solution ,Applied mathematics ,Trigonometric functions ,Ocean Engineering ,Trigonometry ,Oceanography ,Course (navigation) ,Mathematics - Abstract
Van de Ree has provided a solution to what must be a fairly common problem in navigation. The problem may be stated as follows.A ship on a rhumb-line course encounters head-winds and heavy seas requiring her to reduce speed. If she alters course, but does not change the rate of fuel consumption, her speed will be given by (a + b sin A), where A is the course change, a is the speed into the head sea and a + b is the speed in a beam sea. How far should the navigator alter course so that, after a given time, the ship will be nearer the destination than on any other course and, in addition, the labouring of the vessel will be reduced?Van de Ree's trial-and-error solution assumed the destination to be initially 63 miles away, a = 12, b = 5, and the optimization period 1 hour. His solution was to alter course by 20(± 2·5)°. It is possible to obtain a general algebraic solution to this problem, but it requires differentiating complicated trigonometric functions and solving a complicated trigonometric equation, and so the algebraic solution is not practically useful. It is also possible to solve the problem graphically. This solution is by far the simplest one and would be recommended in place of either Van de Ree's laborious numerical solution, or the equally difficult algebraic solution.However, one could question whether the chosen tactic is the appropriate one.
- Published
- 1983
49. Comments on 'The effect of atmospheric refraction in the solar azimuth'
- Author
-
Langley R. Muir
- Subjects
Optics ,Renewable Energy, Sustainability and the Environment ,business.industry ,Solar azimuth angle ,Environmental science ,Atmospheric refraction ,General Materials Science ,business - Published
- 1983
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.