533 research outputs found
De Branges spaces and Krein's theory of entire operators
This work presents a contemporary treatment of Krein's entire operators with
deficiency indices and de Branges' Hilbert spaces of entire functions.
Each of these theories played a central role in the research of both renown
mathematicians. Remarkably, entire operators and de Branges spaces are
intimately connected and the interplay between them has had an impact in both
spectral theory and the theory of functions. This work exhibits the
interrelation between Krein's and de Branges' theories by means of a functional
model and discusses recent developments, giving illustrations of the main
objects and applications to the spectral theory of difference and differential
operators.Comment: 37 pages, no figures. The abstract was extended. Typographical errors
were corrected. The bibliography style was change
Two-dimensional multiscale entropy analysis: applications to image texture evaluation
Complexity measures, defined as measures of irregularity over time scales, are the subject of a growing number of studies as the information they reveal can find utility in a large field of applications. One of the most popular complexity measures is the multiscale entropy. Nevertheless, more and more algorithms dedicated to complexity analyses are proposed to improve the existing ones. However, such measures are available only for one-dimensional time series. For bidimensional data (images), no equivalent algorithm has been proposed to analyze irregularity over spatial scales. We herein introduce a new framework that extends the one-dimensional multiscale entropy (MSE1D) to the bidimensional case (MSE2D). Moreover, a variant of MSE2D is also ModMSE2D). The two new algorithms are tested as new texture analysis frameworks. They are applied to simulated and real data. Our results show that, compared with other existing texture analysis algorithms, MSE2D and ModMSE2D are suitable and powerful tools for image analysis and classification according to their texture patterns. While MSE2D is computationally faster than ModMSE2D, ModMSE2D is more robust to small image sizes. The two methods present interesting performances, and can be as useful as their unidimensional versions in two-dimensional applications
A transformation-based approach to business process management in the cloud
Business Process Management (BPM) has gained a lot of popularity in the last two decades, since it allows organizations to manage and optimize their business processes. However, purchasing a BPM system can be an expensive investment for a company, since not only the software itself needs to be purchased, but also hardware is required on which the process engine should run, and personnel need to be hired or allocated for setting up and maintaining the hardware and the software. Cloud computing gives its users the opportunity of using computing resources in a pay-per-use manner, and perceiving these resources as unlimited. Therefore, the application of cloud computing technologies to BPM can be extremely beneficial specially for small and middle-size companies. Nevertheless, the fear of losing or exposing sensitive data by placing these data in the cloud is one of the biggest obstacles to the deployment of cloud-based solutions in organizations nowadays. In this paper we introduce a transformation-based approach that allows companies to control the parts of their business processes that should be allocated to their own premises and to the cloud, to avoid unwanted exposure of confidential data and to profit from the high performance of cloud environments. In our approach, the user annotates activities and data that should be placed in the cloud or on-premise, and an automated transformation generates the process fragments for cloud and on-premise deployment. The paper discusses the challenges of developing the transformation and presents a case study that demonstrates the applicability of the approach
An Illustrative Case Of LĂ©ri-weill Dyschondrosteosis
We report on a girl presenting Léri-Weill dyschondrosteosis (LWD) due to deletion of the SHOX gene. Her family included individuals with short stature alone or with both short stature and mesomelia or Madelung's deformity. The deletion was demonstrated through detection of hemizygosity for microsatellite markdrs SHOX-CA repeat, DXYS10092, DXYS10093 and DXYS10091 localized around the SHOX gene, with retention of paternal alleles in the proband and three of her sisters who had short stature as the only clinical feature. Hemizygosity for these loci was also observed in their mother, who had short stature too. The deletion in the proband was however larger, including locus DXY 10083. The proband's only sister with normal height did not carry the deletion. Family history suggests transmission of the deletion from the proband's maternal great-grandfather to her grandfather via the Y chromosome, and from the grandfather to the proband's mother via the X chromosome after crossing-over in the pseudoautosomal region proximal to the SHOX gene. Copyright © 2008, Sociedade Brasileira de Genética.314839842Belin, V., Cusin, V., Viot, G., Girlich, D., Toutain, A., Moncla, A., Vekemans, M., Cormier-Daire, V., SHOX mutations in dyschondrosteosis (Léri-Weill syndrome) (1998) Nat Genet, 19, pp. 67-69Benito-Sanz, S., del Blanco, D.G., Aza-Carmona, M., Magano, L.F., Lapunzina, P., Argente, J., Campos-Barros, A., Heath, K.E., PAR1 deletions downstream of SHOX are the most frequent defect in a Spanish cohort of Léri-Weill dyschondrosteosis (LWD) probands (2006) Hum Mutat, 27, p. 1062Benito-Sanz, S., del Blanco, D.G., Huber, C., Thomas, N.S., Aza-Carmona, M., Bunyan, B., Maloney, V., Campos-Barros, A., Characterization of SHOX deletions in Léri-Weill dyschondrosteosis (LWD) reveals genetic heterogeneity and no recombination hotspots (2006) Am J Hum Genet, 79, pp. 409-412Benito-Sanz, S., Thomas, N.S., Huber, C., Gorbenko del Blanco, D., Aza-Carmona, M., Crolla, J.A., Maloney, V., Campos-Barros, A., A novel class of pseudoautosomal region 1 deletions downstream of SHOX Is associated with Léri-Weill dyschondrosteosis (2005) Am J Hum Genet, 77, pp. 533-544Clement-Jones, M., Schiller, S., Rao, E., Blaschke, R.J., Zuniga, A., Zeller, R., Robson, S.C., Strachan, T., The short stature homeobox gene SHOX is involved in skeletal abnormalities in Turner syndrome (2000) Hum Mol Genet, 9, pp. 695-702Ellison, J.W., Wardak, Z., Young, M.F., Gehron Robey, P., Laig-Webster, M., Chiong, W., PHOG, a candidate gene for involvement in the short stature of Turner syndrome (1997) Hum Mol Genet, 6, pp. 1341-1347Filatov, D.A., Gerrard, D.T., High mutation rates in human and ape pseudoautosomal genes (2003) Gene, 317, pp. 67-77Fukami, M., Kato, F., Tajima, T., Yokoya, S., Ogata, T., Transactivation function of an approximately 800-bp evolutionarily conserved sequence at the SHOX 3′ region: Implication for the downstream enhancer (2006) Am J Hum Genet, 78, pp. 167-170Henry, A., Thorburn, M.J., Madelung's deformity. A clinical and cytogenetic study (1967) J Bone Joint Surg, 49 B, pp. 66-73Jorge, A.A., Souza, S.C., Nishi, M.Y., Billerbeck, A.E., Liborio, D.C., Kim, C.A., Arnhold, I.J., Mendonca, B.B., SHOX mutations in idiopathic short stature and Leri-Weill dyschondrosteosis: Frequency and phenotypic variability (2007) Clin Endocrinol, 66, pp. 130-135Lien, S., Szyda, J., Schechinger, B., Rappold, G., Arnheim, N., Evidence for heterogeneity in recombination in the human pseudoautosomal region: High resolution analysis by sperm typing and radiation-hybrid mapping (2000) Am J Hum Genet, 66, pp. 557-566Rao, E., Weiss, B., Fukami, M., Rump, A., Niesler, B., Mertz, A., Muroya, K., Winkelmann, M., Pseudoautosomal deletions encompassing a novel homeobox gene cause growth failure in idiopathic short stature and Turner syndrome (1997) Nat Genet, 16, pp. 54-63Rappold, G., Blum, W.F., Shavrikova, E.P., Crowe, B.J., Roeth, R., Quigley, C.A., Ross, J.L., Niesler, B., Genotypes and phenotypes in children with short stature: Clinical indicators of SHOX haploinsufficiency (2007) J Med Genet, 44, pp. 306-313Rappold, G.A., Fukami, M., Niesler, B., Schiller, S., Zumkeller, W., Bettendorf, M., Heinrich, U., Onigata, K., Deletions of the homeobox gene SHOX(short stature homeobox) are an important cause of growth failure in children with short stature (2002) J Clin Endocrinol Metab, 87, pp. 1402-1406Schneider, K.U., Sabherwal, N., Jantz, K., Röth, R., Muncke, N., Blum, W.F., Cutler Jr, G.B., Rappold, G., Identification of major raombinant hotspot in patients with short stature and SHOX deficiency (2005) Am J Hum Genet, 77, pp. 89-96Shears, D.J., Vassal, H.J., Goodman, F.R., Palmer, R.W., Reardon, W., Superti-Furga, A., Scambler, P.J., Winter, R.M., Mutation and deletion of the pseudoautosomal gene SHOX cause Léri-Weill dyschondrosteosis (1998) Nat Genet, 19, pp. 70-72Zebala, L.P., Manske, P.R., Goldfarb, C.A., (200't) Madelung's deformity: A spectrum of presentation.. The J Hand Surg, 32 A, pp. 1393-1401Zinn, A.R., Ramos, P., Ross, J., (1006) A second recombination hotspot associated with SHOX deletions Am J Hum Genet, 78, pp. 523-52
Electron trapping and acceleration on a downward density ramp: a two-stage approach
In a recent experiment at Lawrence Berkeley National Laboratory (Geddes et al 2008 Phys. Rev. Lett. 100 215004), electron bunches with about 1MeV mean energy and small absolute energy spread (about 0.3MeV) were produced by plasma wave breaking on a downward density ramp. It was then speculated that such a bunch might be accelerated further in a plasma of low constant density, while mostly preserving its small absolute energy spread. This would then lead to a bunch with a high mean energy and very low relative energy spread. In this paper, trapping of a low-energy, low-spread electron bunch on a downward density ramp, followed by acceleration in a constant-density plasma, has been explored through particle-in-cell simulations. It has been found that the scheme works best when it is used as a separate injection stage for a laserwakefield accelerator, where the injection and acceleration stages are separated by a vacuum gap
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