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See detailNonmyeloablative stem cell transplantation with CD8-depleted or CD34-selected peripheral blood stem cells.
Baron, Frédéric ULg; Baudoux, Etienne ULg; Frere, Pascale ULg et al

in Journal of Hematotherapy & Stem Cell Research (2002), 11(2), 301-14

To decrease the incidence of graft-versus-host disease (GVHD) observed after nonmyeloablative stem cell transplantation (NMSCT), we studied the feasibility of CD8-depleted or CD34-selected NMSCT followed ... [more ▼]

To decrease the incidence of graft-versus-host disease (GVHD) observed after nonmyeloablative stem cell transplantation (NMSCT), we studied the feasibility of CD8-depleted or CD34-selected NMSCT followed by CD8-depleted preemptive donor lymphocyte infusion (DLI) given in incremental doses on days 40 and 80. Fourteen patients with high-risk malignancies and an HLA-identical sibling (n = 8) or alternative donor (n = 6) but ineligible for a conventional transplant were included. Nonmyeloablative conditioning regimen consisted in 2 Gy total body irradiation (TBI) alone, 2 Gy TBI and fludarabine (previously untreated patients) or cyclophosphamide and fludarabine (patients who had previously received > or =12 Gy TBI). Patients 1-4 (controls) received unmanipulated peripheral blood stem cells (PBSC) and DLI and patients 5-14 CD8-depleted or CD34-selected PBSC followed by CD8-depleted DLI. Post-transplant immunosuppression was carried out with cyclosporine A (CsA) and mycophenolate mofetil (MMF). Initial engraftment was seen in all patients, but 1 patient (7%) later rejected her graft. The actuarial 180-day incidence of grades II-IV acute GVHD was 75% for patients 1-4 versus 0% for patients 5-14 (p = 0.0019). Five of 14 patients were in complete remission (CR) 180 days after the transplant and 6/14 had partial responses. The 1-year survival rate was 69%, and nonrelapse and relapse mortality rates were 16 and 18%, respectively. We conclude that CD8-depleted or CD34-selected NMSCT followed by CD8-depleted DLI is feasible and considerably decreases the incidence of acute GVHD while preserving engraftment and apparently also the graft-versus-leukemia (GVL) effect. Further studies are needed to confirm this encouraging preliminary report. [less ▲]

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See detailNonmyeloablative Transplantation
Baron, Frédéric ULg; Sandmaier, Brenda

in Hematopoietic Stem Cell Transplantation (2008)

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See detailNonnius et la cure de Spa
Marganne, Marie-Hélène ULg; Mélard, Marc; Lecomte, Jean et al

in Nonnius en de 'Diëtetiek'. Derde Symposium Geschiedenis der Geneeskundige Wetenschappen, 2 december 1995, Koninklijke Academie voor Genneeskunde van België (1996)

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See detailNonparametric additive location-scale models for interval censored data
Lambert, Philippe ULg

in Statistics and computing (2013), 23

An nonparametric additive model for the location and dispersion of a continuous response with an arbitrary smooth conditional distribution is proposed. B-splines are used to specify the three components ... [more ▼]

An nonparametric additive model for the location and dispersion of a continuous response with an arbitrary smooth conditional distribution is proposed. B-splines are used to specify the three components of the model. It can deal with interval censored data and multiple covariates. After a simulation study, the relation between age, the number of years of full-time education and the net income (provided as intervals) available per person in Belgian households is studied from survey data. [less ▲]

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See detailNonparametric and bootstrap techniques applied to financial risk modeling
Hambuckers, julien ULg

Doctoral thesis (2015)

For the purpose of quantifying financial risks, risk managers need to model the behavior of financial variables. However, the construction of such mathematical models is a difficult task that requires ... [more ▼]

For the purpose of quantifying financial risks, risk managers need to model the behavior of financial variables. However, the construction of such mathematical models is a difficult task that requires careful statistical approaches. Among the important choices that must be addressed,we can list the error distribution, the structure of the variance process, the relationship between parameters of interest and explanatory variables. In particular, one may avoid procedures that rely either on too rigid parametric assumptions or on inefficient estimation procedures. In this thesis, we develop statistical procedures that tackle some of these issues, in the context of three financial risk modelling applications. In the first application, we are interested in selecting the error distribution in a multiplicative heteroscedastic model without relying on a parametric volatility assumption. To avoid this uncertainty, we develop a set of model estimation and selection tests relying on nonparametric volatility estimators and focusing on the tails of the distribution. We illustrate this technique on UBS, BOVESPA and EUR/USD daily stock returns. In the second application, we are concerned by modeling the tail of the operational losses severity distribution, conditionally to several covariates. We develop a flexible conditional GPD model, where the shape parameter is an unspecified link function (nonparametric part) of a linear combination of covariates (single index part), avoiding the curse of dimensionality. We apply successfully this technique on two original databases, using macroeconomic and firm-specific variables as covariates. In the last application, we provide an efficient way to estimate the predictive ability of trading algorithms. Instead of relying on subjective and noisy sample splitting techniques, we propose an adaptation of the .632 bootstrap technique to the time series context. We apply these techniques on stock prices to compare 12,000 trading rules parametrizations and show that none can beat a simple buy-and-hold strategy. [less ▲]

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See detailNonparametric censored regression using preliminary kernel smoothing
Heuchenne, Cédric ULg; Van Keilegom, Ingrid

in Proceedings of the 6th World Congress of the Bernoulli Society for Mathematical Statistics and Probability and the 67th Annual Meeting of the IMS (2004)

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See detailNonparametric control charts: economic statistical design
Marcos Alvarez, Alejandro ULg; Heuchenne, Cédric ULg; Faraz, Alireza ULg

E-print/Working paper (2016)

This paper studies economic statistical designs (ESD) for nonparametric control charts based on the sign and Wilcoxon tests. The main advantage of the procedures is that, except for the tested location ... [more ▼]

This paper studies economic statistical designs (ESD) for nonparametric control charts based on the sign and Wilcoxon tests. The main advantage of the procedures is that, except for the tested location parameter, they do not use either any parametric distribution for the quality characteristic or any information about the possible involved parameters, neither in the in-control nor in the out-of-control state. This is made possible by minimizing a cost function specified independently of these quantities. Unlike the ESD for the $\overline{x}$ chart, the resulting charts designs are robust to changes of the distributions of the observations (in control or out of control), provide reliable statistical guarantees when the $\overline{x}$ chart ESD does not and stay competitive even when the strong assumptions of the $\overline{x}$ chart ESD are fully satisfied. These new techniques can therefore be applied to a definitely wider class of problems and their designs may stay constant over time without losing performance. [less ▲]

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See detailNonparametric estimation and bootstrap inference on recent trends in atmospheric ethane
Friedrich, Marina; Reuvers, H.; Smeekes, S. et al

Conference (2015, December 12)

Ethane is the most abundant non-methane hydrocarbon in the Earth's atmosphere and an important precursor of tropospheric ozone. Its monitoring is therefore crucial for the characterization of air quality ... [more ▼]

Ethane is the most abundant non-methane hydrocarbon in the Earth's atmosphere and an important precursor of tropospheric ozone. Its monitoring is therefore crucial for the characterization of air quality and of the transport of tropospheric pollution. Ethane is also an indirect greenhouse gas, influencing the atmospheric lifetime of methane. The main sources of ethane are located in the northern hemisphere, and the dominating emissions are associated to production and transport of natural gas. A preliminary trend analysis was conducted using measurements performed in the Swiss Alps. Over the last two decades, the trend of ethane showed a decline of around 1% per year, thanks to a reduction of fugitive emissions of fossil fuel sources. However, a recent upturn potentially attributed to the massive exploitation of shale gas and tight oil reservoirs in North America was found. The goal is to investigate the presence and form of changes in trend functions using nonparametric techniques. The possible location of such changes is investigated. In addition, nonparametric estimation techniques are used to allow for nonlinear trend functions. Given the nonstandard nature of the measurements we rely on dependent wild bootstrap techniques to conduct inference on possible breaks in linear trends and on nonparametric trend functions. [less ▲]

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See detailNonparametric Mean Preservation in Censored Regression
Heuchenne, Cédric ULg

Book published by VDM Verlag (2009)

The aim of this book is to estimate the conditional mean of some functions depending on the response variable Y (moments, distributions...) in regression models where this response is possibly censored ... [more ▼]

The aim of this book is to estimate the conditional mean of some functions depending on the response variable Y (moments, distributions...) in regression models where this response is possibly censored. In parametric regression, polynomial and nonlinear conditional means are estimated in a new way while, in nonparametric regression, some new estimators are provided to approximate general L-functionals (conditional mean, trimmed mean, quantiles...). The ideas developed in those methods lead to establish more general results in nonparametric estimation of the conditional mean of functions depending on Y and other variables and where the response can follow other schemes of incomplete data (not only censored but also missing or length-biased data). For each procedure, asymptotic properties are established while finite sample behavior is studied via simulations. Examples from a variety of areas highlight the interest of using the proposed methodologies in practice. [less ▲]

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See detailNonparametric regression with cross-sectional data: an alternative to conditional product-limit estimators
Heuchenne, Cédric ULg; Laurent, Géraldine ULg

E-print/Working paper (2014)

Suppose the random vector (X,Y) satisfies the nonparametric regression model Y=m(X)+varepsilon, where m(x)=E[Y|X=x] and sigma²(x)=Var[varepsilon|X=x] are unknown smooth functions and the error varepsilon ... [more ▼]

Suppose the random vector (X,Y) satisfies the nonparametric regression model Y=m(X)+varepsilon, where m(x)=E[Y|X=x] and sigma²(x)=Var[varepsilon|X=x] are unknown smooth functions and the error varepsilon has zero mean and finite variance conditionally on X=x. The pair (X,Y) is obtained by cross-sectional sampling involving left-truncated and right-censored responses. The considered model is completely nonparametric but the conditional truncation distribution is assumed to be known. The novelty of this work is twofold: first, it extends the results on cross-sectional data to the conditional case and second, it generalizes the length bias results in the conditional case to right censoring and to any truncation distribution. New estimators for m(.) and sigma²(.) are constructed and relevant tools are used to quickly provide the main asymptotic properties for this kind of estimators. Extensive simulations are carried out and show that the new estimators outperform classical nonparametric estimators for left-truncated and right-censored data (when the truncation model is known). Finally, a data set on the mortality of diabetics is analyzed. [less ▲]

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See detailNonparametric regression with parametric selection bias
Heuchenne, Cédric ULg; Laurent, Géraldine ULg

in Proceedings of the 14th Conference of the ASMDA International Society (ASMDA2011) (2011, June)

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See detailNonparametric subspace identification of nonlinear structures - Application to a spacecraft
Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg

in Proceedings of the 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference (2013, April)

The objective of the present paper is to address the identification of a strongly nonlinear satellite structure by exploiting a new nonlinear subspace identification method formulated in the frequency ... [more ▼]

The objective of the present paper is to address the identification of a strongly nonlinear satellite structure by exploiting a new nonlinear subspace identification method formulated in the frequency domain, referred to as the FNSI method. The modal parameters of the underlying linear structure and the coefficients of the nonlinear internal forces will be estimated by this approach. Moreover, because a priori knowledge about nonlinear behaviour may be limited, the paper also proposes a nonparametric spline-based modelling strategy, encapsulated in the FNSI method. The application of interest is the SmallSat spacecraft developed by EADS-Astrium, which possesses an impact-type nonlinear device consisting of eight mechanical stops limiting the motion of an inertia wheel mounted on an elastomeric interface. [less ▲]

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See detailNonpharmacological management
Bruyère, Olivier ULg

in Osteoporosis International (2013, April), 24(Suppl.1), 76

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See detailNonPharmacological modalities, nutraceuticals and dietary supplements as therapies
Henrotin, Yves ULg; Marty, Marc; Mobasheri, Ali

in Addressing Unmet Needs in Osteoarthritis (2013)

This chapter discusses and critically appraises the nonpharmacological approaches that are currently available

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See detailNonpharmacological Therapies in the Management of Osteoarthritis
Henrotin, Yves ULg

Book published by Bentham Science Publishers Ltd. (2012)

Detailed reference viewed: 28 (3 ULg)