Search

Your search keyword '"Sorrell J"' showing total 355 results
Start Over Author "Sorrell J"
355 results on '"Sorrell J"'

1. Boosting in the Presence of Massart Noise

Author

Diakonikolas, I, Impagliazzo, R, Kane, D, Lei, R, Sorrell, J, and Tzamos, C

Abstract

We study the problem of boosting the accuracy of a weak learner in the (distribution-independent) PAC model with Massart noise. In the Massart noise model, the label of each example x is independently misclassified with probability η(x) ≤ η, where η < 1/2. The Massart model lies between the random classification noise model and the agnostic model. Our main positive result is the first computationally efficient boosting algorithm in the presence of Massart noise that achieves misclassification error arbitrarily close to η. Prior to our work, no non-trivial booster was known in this setting. Moreover, we show that this error upper bound is best possible for polynomial-time black-box boosters, under standard cryptographic assumptions. Our upper and lower bounds characterize the complexity of boosting in the distribution-independent PAC model with Massart noise. As a simple application of our positive result, we give the first efficient Massart learner for unions of high-dimensional rectangles.

Published
2021

3. Effects of Sacubitril/Valsartan Versus Irbesartan in Patients With Chronic Kidney Disease: A Randomized Double-Blind Trial

Author

Haynes, Richard, Judge, Parminder K., Staplin, Natalie, Herrington, William G., Storey, Benjamin C., Bethel, Angelyn, Bowman, Louise, Brunskill, Nigel, Cockwell, Paul, Hill, Michael, Kalra, Philip A., McMurray, John J.V., Taal, Maarten, Wheeler, David C., Landray, Martin J., Baigent, Colin, Haynes, R., Judge, P.K., Staplin, N., Herrington, W.G., Storey, B.C., Bethel, A., Bowman, L., Brunskill, N., Cockwell, P., Hill, M., Kalra, P.A., McMurray, J.J., Taal, M., Wheeler, D.C., Landray, M.J., Baigent, C., Baigent, C., Haynes, R., Landray, M.J., Dayanandan, R., Baxter, A., Staplin, N., Bethel, A., Bowman, L., Brunskill, N., Cockwell, P., Herrington, W.G., Hill, M., Judge, P.K., Kalra, P.A., Knott, C., McMurray, J.J.V., Murphy, K., Taal, M., Wheeler, D.C., Wheatley, K., Emberson, J., Tomson, C., Roderick, P., Clark, L., Annand, J., Marks, A., Rose, H., Taal, M., Brear, T., Havill, L., McKinnell, J., Melbourne, S., Shardlow, A., Smith, J., Stone, C., Rowe, P., Connor, A., Wooding, J., Taylor, J., Bough, L., Purse, K., Wignall, S., Winter-Goodwin, B., Brunskill, N., Bailey, B., Barratt, J., Bielecka, E., McCartney, M., Hutchison, A., Asari, A., Waring, D., Sajith, R., Walton, H., Mikhail, A., Hilldrup, I., Latif, F., Shrivastava, R., Nicholas, J., Byrne, T., Sandhu, K.S., Tan, B.K., Ward, J., Whistance-Smith, D., Khwaja, A., Jackson, Y., Kawar, B., Middle, J., Sorrell, J., Byrne, C., Brand, S., McHaffie, E., Haynes, R., Crosbie, S., Judge, P.K., Lafferty, K., Ruse, S., Sharples, E., Storey, B.C., Sampson, A., Kirk, A., Lewis, R., Vinall, L., Watkins, L., Williams, F., Cockwell, P., Anderson, N., Dutton, M., Ferro, C., Fifer, L., Smith, S., Stringer, S., Bhandary, N., Alchi, B., Foxton, J., Jones, L., D’Souza, R., Harrison, D., Heddon, S., Wheeler, D.C., Caplin, B., Damian, E., Sobande, T., Davies, S., Edwards, C., Matthews, C., Plaza, M., Reddy, S., Kalra, P.A., Chiu, D., Haydock, L., Kershaw, M., Wilson, C., Vassallo, D., Methven, S., Bowles, J., Collins, E., Dawson, S., Power, A., Kardasz, S., Laven, C., Wroe, C., Eardley, K., Donaldson, D., Tonks, L., Ayub, W., Evans, G., Hewins, S., Fraser, D., Bagshawe, J., Foxwell, D., Williams, A., Border, D., Birch, S., Griffiths, L., Jones, C., McCullough, K., Molyneux, R., and Richardson, D.

Published
2018
Full Text
View/download PDF

24. Cost-effectiveness analysis of a randomized clinical trial of early versus deferred endovenous ablation of superficial venous reflux in patients with venous ulceration

Author

Epstein, D M, primary, Gohel, M S, additional, Heatley, F, additional, Liu, X, additional, Bradbury, A, additional, Bulbulia, R, additional, Cullum, N, additional, Nyamekye, I, additional, Poskitt, K R, additional, Renton, S, additional, Warwick, J, additional, Davies, A H, additional, Read, D, additional, Hargreaves, S, additional, Dhillon, K, additional, Anwar, M, additional, Liddle, A, additional, Brown, H, additional, Mercer, K, additional, Gill, F, additional, Liu, A, additional, Jepson, W, additional, Wormwell, A, additional, Rafferty, H, additional, Kaur, R, additional, Solomon, E, additional, Sritharan, K, additional, Velineni, R, additional, Lim, C S, additional, Busuttil, A, additional, Bootun, R, additional, Bicknell, C, additional, Jenkins, M, additional, Lane, T, additional, Serjeant, E, additional, Poskitt, K, additional, Waldron, J, additional, Wolfrey, G, additional, Slim, F, additional, Davies, C, additional, Emerson, L, additional, Grasty, M, additional, Whyman, M, additional, Wakeley, C, additional, Cooper, A, additional, Clapp, J, additional, Hogg, N, additional, Howard, J, additional, Dyer, J, additional, Lyes, S, additional, Teemul, D, additional, Harvey, K, additional, Pride, M, additional, Kindon, A, additional, Price, H, additional, Flemming, L, additional, Birch, G, additional, Holmes, H, additional, Weston, J, additional, Joseph, T, additional, Eiffel, R, additional, Ojimba, T, additional, Wilson, T, additional, Hodgson, A, additional, Robinson, L, additional, Todhunter, J, additional, Heagarty, D, additional, Mckeane, A, additional, McCarthy, R, additional, Barwell, J, additional, Northcott, C, additional, Elstone, A, additional, West, C, additional, Chong, P, additional, Gerrard, D, additional, Croucher, A, additional, Levy, S, additional, Martin, C, additional, Craig, T, additional, Carradice, D, additional, Firth, A, additional, Clarke, E, additional, Oswald, A, additional, Sinclair, J, additional, Chetter, I, additional, El-Sheikha, J, additional, Nandhra, S, additional, Leung, C, additional, Scott, J, additional, Dewhirst, N, additional, Woods, J, additional, Russell, D, additional, Darwood, R, additional, Troxler, M, additional, Thackeray, J, additional, Bell, D, additional, Watson, D, additional, Williamson, L, additional, Coulston, J, additional, Eyers, P, additional, Darvall, K, additional, Hunter, I, additional, Stewart, A, additional, Moss, A, additional, Rewbury, J, additional, Adams, C, additional, Vickery, L, additional, Foote, L, additional, Durman, H, additional, Venn, F, additional, Hill, P, additional, James, K, additional, Luxton, F, additional, Greenwell, D, additional, Roberts, K, additional, Mitchell, S, additional, Tate, M, additional, Mills, H, additional, Garnham, A, additional, Hobbs, S, additional, McIntosh, D, additional, Green, M, additional, Collins, K, additional, Rankin, J, additional, Poulton, P, additional, Isgar, V, additional, Trivedi, M, additional, Kafeza, M, additional, Parsapour, S, additional, Moore, H, additional, Najem, M, additional, Connarty, S, additional, Albon, H, additional, Lloyd, C, additional, Trant, J, additional, Vohra, R, additional, McCormack, J, additional, Marshall, J, additional, Hardy, V, additional, Rogoveanu, R, additional, Goff, W, additional, Gidda, R, additional, Merotra, S, additional, Shiralkar, S, additional, Jayatunga, A, additional, Pathak, R, additional, Rehman, A, additional, Randhawa, K, additional, Lewis, J, additional, Fullwood, S, additional, Jennings, S, additional, Cole, S, additional, Wall, M, additional, Ranaboldo, C, additional, Hulin, S, additional, Clarke, C, additional, Fennelly, R, additional, Cooper, R, additional, Boyes, R, additional, Draper, C, additional, Harris, L, additional, Mead, D, additional, Kelly, L, additional, Bate, G, additional, Davies, H, additional, Popplewell, M, additional, Claridge, M, additional, Gannon, M, additional, Khaira, H, additional, Scriven, M, additional, Wilmink, T, additional, Adam, D, additional, Nasr, H, additional, Dodd, D, additional, Nawaz, S, additional, Humphreys, J, additional, Barnes, M, additional, Sorrell, J, additional, Swift, D, additional, Phillips, P, additional, Trender, H, additional, Fenwick, N, additional, Rittoo, D, additional, Baker, S, additional, Mitchell, R, additional, Andrews, S, additional, Williams, S, additional, Stephenson, J, additional, Holloway, S, additional, Hayes, W, additional, Day, J, additional, Clayton, C, additional, Harding, D, additional, Thompson, A, additional, Gibson, A, additional, Murphy, Z, additional, and Smith, T, additional

Published
2019
Full Text
View/download PDF

25. Human Mesenchymal Stem Cells Induced to Differentiate as Chondrocytes Follow a Biphasic Pattern of Extracellular Matrix Production()

Author

Sorrell, J. Michael, Somoza, Rodrigo A., and Caplan, Arnold I.

Subjects
Chondrocytes, Humans, Cell Differentiation, Mesenchymal Stem Cells, Proteoglycans, Collagen, Article, Cell Aggregation, Extracellular Matrix
Abstract

Regenerative medicine and tissue engineering studies are actively developing novel means to repair adult articular cartilage defects using biological approaches. One such approach is the harnessing of adult human therapeutic cells such as those referred to as mesenchymal stem cells. Upon exposure to chondrogenic signals, these cells differentiate and initiate the production of a complex and voluminous cartilaginous matrix that is crucial to both the structure and function of cartilage. Furthermore, this complexity requires the time-sensitive activation of a large number of genes to produce the components of this matrix. The current study analyzed the kinetics of matrix production in an aggregate culture model where adult human mesenchymal stem cells were induced to differentiate as chondrocytes. The results indicate the existence of a biphasic mode of differentiation and maturation during which matrix genes and molecules are differentially activated and secreted. These results have important implications for developing novel approaches for the creation of tissue engineered articular cartilage. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1757-1766, 2018.

Published
2017

26. Age-related differences in human skin proteoglycans

Author

Carrino, David A., Calabro, Anthony, Darr, Aniq B., Dours-Zimmermann, Maria T., Sandy, John D., Zimmermann, Dieter R., Sorrell, J Michael, Hascall, Vincent C., and Caplan, Arnold I.

Subjects
carbohydrates (lipids), integumentary system
Abstract

Previous work has shown that versican, decorin and a catabolic fragment of decorin, termed decorunt, are the most abundant proteoglycans in human skin. Further analysis of versican indicates that four major core protein species are present in human skin at all ages examined from fetal to adult. Two of these are identified as the V0 and V1 isoforms, with the latter predominating. The other two species are catabolic fragments of V0 and V1, which have the amino acid sequence DPEAAE as their carboxyl terminus. Although the core proteins of human skin versican show no major age-related differences, the glycosaminoglycans (GAGs) of adult skin versican are smaller in size and show differences in their sulfation pattern relative to those in fetal skin versican. In contrast to human skin versican, human skin decorin shows minimal age-related differences in its sulfation pattern, although, like versican, the GAGs of adult skin decorin are smaller than those of fetal skin decorin. Analysis of the catabolic fragments of decorin from adult skin reveals the presence of other fragments in addition to decorunt, although the core proteins of these additional decorin catabolic fragments have not been identified. Thus, versican and decorin of human skin show age-related differences, versican primarily in the size and the sulfation pattern of its GAGs and decorin in the size of its GAGs. The catabolic fragments of versican are detected at all ages examined, but appear to be in lower abundance in adult skin compared with fetal skin. In contrast, the catabolic fragments of decorin are present in adult skin, but are virtually absent from fetal skin. Taken together, these data suggest that there are age-related differences in the catabolism of proteoglycans in human skin. These age-related differences in proteoglycan patterns and catabolism may play a role in the age-related changes in the physical properties and injury response of human skin

Published
2017

32. READER COMMENTS.

Author

LIPPI, MARISH, SORRELL, J. MARY, WILEY, SHAWN, YEE, BILL, FORD, SIDNEY, ENGEL, MARY, TAYLOR, TERFSA, and BROWN, ROSE

Subjects
*EARLY death, *SCHOOL year
Abstract

The article focuses on the heartfelt responses to Joe Sexton's piece about Richard Henderson, a crossing guard for Avenues The World School in Manhattan, highlighting his dedication to protecting children and his impact on their lives, eliciting emotional reactions.

Published
2024

36. Human mesenchymal stem cells induced to differentiate as chondrocytes follow a biphasic pattern of extracellular matrix production.

Author

Sorrell, J. Michael, Somoza, Rodrigo A., and Caplan, Arnold I.

Subjects
*MESENCHYMAL stem cells, *CARTILAGE, *EXTRACELLULAR matrix, *MICROARRAY technology, *TISSUE engineering
Abstract

ABSTRACT: Regenerative medicine and tissue engineering studies are actively developing novel means to repair adult articular cartilage defects using biological approaches. One such approach is the harnessing of adult human therapeutic cells such as those referred to as mesenchymal stem cells. Upon exposure to chondrogenic signals, these cells differentiate and initiate the production of a complex and voluminous cartilaginous matrix that is crucial to both the structure and function of cartilage. Furthermore, this complexity requires the time‐sensitive activation of a large number of genes to produce the components of this matrix. The current study analyzed the kinetics of matrix production in an aggregate culture model where adult human mesenchymal stem cells were induced to differentiate as chondrocytes. The results indicate the existence of a biphasic mode of differentiation and maturation during which matrix genes and molecules are differentially activated and secreted. These results have important implications for developing novel approaches for the creation of tissue engineered articular cartilage. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1757–1766, 2018. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

37. Age-related differences in human skin proteoglycans

Author

Carrino, D A, Calabro, A, Darr, A B, Dours-Zimmermann, M T, Sandy, J D, Zimmermann, D R, Sorrell, J M, Hascall, V C, Caplan, A I, and University of Zurich

Subjects
1303 Biochemistry, 10049 Institute of Pathology and Molecular Pathology, 610 Medicine & health
Published
2011

38. Regulation of gastric emptying rate and its role in nutrient-induced GLP-1 secretion in rats after vertical sleeve gastrectomy

Author

Chambers, AP, Smith, EP, Begg, DP, Grayson, BE, Sisley, S, Greer, T, Sorrell, J, Lemmen, L, LaSance, K, Woods, SC, Seeley, RJ, D'Alessio, DA, Sandoval, DA, Chambers, AP, Smith, EP, Begg, DP, Grayson, BE, Sisley, S, Greer, T, Sorrell, J, Lemmen, L, LaSance, K, Woods, SC, Seeley, RJ, D'Alessio, DA, and Sandoval, DA

Abstract

Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) are effective weight loss surgeries that also improve glucose metabolism. Rapid, early rises of circulating insulin and glucagon-like peptide-1 (GLP-1) concentrations following food ingestion are characteristic of these procedures. The purpose of the current study was to test the hypothesis that postprandial hormone release is due to increased nutrient emptying from the stomach. Radioscintigraphy and chemical and radiolabeled tracers were used to examine gastric emptying in rat models of VSG and RYGB surgery. Intraduodenal nutrient infusions were used to assess intestinal GLP-1 secretion and nutrient sensitivity in VSG rats compared with shams. Five minutes after a nutrient gavage, the stomachs of RYGB and VSG rats were completely emptied, whereas only 6.1% of the nutrient mixture had emptied from sham animals. Gastric pressure was increased in VSG animals, and rats with this procedure did not inhibit gastric emptying normally in response to increasing caloric loads of dextrose or corn oil, and they did not respond to neural or endocrine effectors of gastric motility. Finally, direct infusion of liquid nutrients into the duodenum caused significantly greater GLP-1 release in VSG compared with shams, indicating that increases in GLP-1 secretion after VSG are the result of both greater gastric emptying rates and altered responses at the level of the intestine. These findings demonstrate greatly accelerated gastric emptying in rat models of RYGB and VSG. In VSG this is likely due to increased gastric pressure and reduced responses to inhibitory feedback from the intestine. © 2014 the American Physiological Society.

Published
2014

39. MGAT2 deficiency and vertical sleeve gastrectomy have independent metabolic effects in the mouse

Author

Mul, JD, Begg, DP, Haller, AM, Pressler, JW, Sorrell, J, Woods, SC, Farese, RV, Seeley, RJ, Sandoval, DA, Mul, JD, Begg, DP, Haller, AM, Pressler, JW, Sorrell, J, Woods, SC, Farese, RV, Seeley, RJ, and Sandoval, DA

Abstract

Vertical sleeve gastrectomy (VSG) is currently one of the most effective treatments for obesity. Despite recent developments, the underlying mechanisms that contribute to the metabolic improvements following bariatric surgery remain unresolved. VSG reduces postprandial intestinal triglyceride (TG) production, but whether the effects of VSG on intestinal metabolism are related to metabolic outcomes has yet to be established. The lipid synthesis enzyme acyl CoA:monoacylglycerol acyltransferase-2 (Mogat2; MGAT2) plays a crucial role in the assimilation of dietary fat in the intestine and in regulation of adiposity stores as well. Given the phenotypic similarities between VSG-operated and MGAT2-deficient animals, we reasoned that this enzyme could also have a key role in mediating the metabolic benefits of VSG. However, VSG reduced body weight and fat mass and improved glucose metabolism similarly in whole body MGAT2-deficient (Mogat2-/-) mice and wild-type littermates. Furthermore, along with an increase in energy expenditure, surgically naive Mogat2-/- mice had altered macronutrient preference, shifting preference away from fat and toward carbohydrates, and increased locomotor activity. Collectively, these data suggest that the beneficial effects of VSG on body weight and glucose metabolism are independent of MGAT2 activity and rather that they are separate from the effects of MGAT2 deficiency. Because MGAT2 inhibitors are proposed as a pharmacother-apeutic option for obesity, our data suggest that, in addition to increasing energy expenditure, shifting macronutrient preference away from fat could be another important mechanism by which these compounds could contribute to weight loss.

Published
2014

43. Age-related differences in human skin proteoglycans

Author

Carrino, D. A., primary, Calabro, A., additional, Darr, A. B., additional, Dours-Zimmermann, M. T., additional, Sandy, J. D., additional, Zimmermann, D. R., additional, Sorrell, J. M., additional, Hascall, V. C., additional, and Caplan, A. I., additional

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results