Claire Thomas - Academia.edu (original) (raw)

Papers by Claire Thomas

Journal of Applied Physiology, 2007

Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human pe... more Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human permeabilized muscle fibers. The effects of concurrent hypoxic/endurance training on mitochondrial respiration in permeabilized fibers in trained athletes were investigated. Eighteen endurance athletes were divided into two training groups: normoxic (Nor, n ϭ 8) and hypoxic (H, n ϭ 10). Three weeks (W1-W3) of endurance training (5 sessions of 1 h to 1 h and 30 min per week) were completed. All training sessions were performed under normoxic [160 Torr inspired PO2 (PI O 2 )] or hypoxic conditions (Ϸ100 Torr PI O 2 , Ϸ3,000 m) for Nor and H group, respectively, at the same relative intensity. Before and after the training period, an incremental test to exhaustion in normoxia was performed, muscle biopsy samples were taken from the vastus lateralis, and mitochondrial respiration in permeabilized fibers was measured. Peak power output (PPO) increased by 7.2% and 6.6% (P Ͻ 0.05) for Nor and H, respectively, whereas maximal O2 uptake (V O2 max) remained unchanged: 58.1 Ϯ 0.8 vs. 61.0 Ϯ 1.2 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 and 58.5 Ϯ 0.7 vs. 58.3 Ϯ 0.6 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 for Nor and H, respectively, between pretraining (W0) and posttraining (W4). Maximal ADP-stimulated mitochondrial respiration significantly increased for glutamate ϩ malate (6.27 Ϯ 0.37 vs. 8.51 Ϯ 0.33 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) and significantly decreased for palmitate ϩ malate (3.88 Ϯ 0.23 vs. 2.77 Ϯ 0.08 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) in the H group. In contrast, no significant differences were found for the Nor group. The findings demonstrate that 1) a 3-wk training period increased the PPO at sea level without any changes in V O2 max, and 2) a 3-wk hypoxic exercise training seems to alter the intrinsic properties of mitochondrial function, i.e., substrate preference. endurance exercise; substrate preference; hypoxic stress; aerobic adaptation; muscle biopsy Address for reprint requests and other correspondence: B. Roels, School of Sport and Education, Brunel Univ.,

European Journal of Applied Physiology, 2009

Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposu... more Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposure to hypoxia is suYcient to induce beneWcial muscular adaptations mediated via hypoxia-inducible transcription factors (HIF). We previously demonstrated (Mounier et al. Med Sci Sports Exerc 38:1410-1417) that leukocytes respond to hypoxia with a marked inter-individual variability in HIF-1 mRNA. This study compared the eVects of 3 weeks of intermittent hypoxic training on hif gene expression in both skeletal muscle and leukocytes. Male endurance athletes (n = 19) were divided into an Intermittent Hypoxic Exposure group (IHE) and a Normoxic Training group (NT) with each group following a similar 3-week exercise training program. After training, the amount of HIF-1 mRNA in muscle decreased only in IHE group (¡24.7%, P < 0.05) whereas it remained unchanged in leukocytes in both groups. The levels of vEGF 121 and vEGF 165 mRNA in skeletal muscle increased signiWcantly after training only in the NT group (+82.5%, P < 0.05 for vEGF 121 ; +41.2%, P < 0.05 for vEGF 165 ). In leukocytes, only the IHE group showed a signiWcant change in vEGF 165 (¡28.2%, P < 0.05). The signiWcant decrease in HIF-1 mRNA in skeletal muscle after hypoxic training suggests that transcriptional and post-transcriptional regulations of the hif-1 gene are diVerent in muscle and leukocytes.

Our work deals with the synthesis of multispectral images at a better spatial resolution by the m... more Our work deals with the synthesis of multispectral images at a better spatial resolution by the means of another image having such a resolution. We show the lack of standard procedure to assess the expected benefits of fused products. We discuss the case of the reference that is missing in most cases. We discuss the principles of the assessment protocol. One principle is that the constructed synthetic images should be close to reality. The second principle is that the fused products should offer a strong consistency with the original data set. This results into two properties of the fused products. We propose a protocol that assesses the quality of fused products with respect to these properties. We define a general framework and the protocol is still open.

Most of the satellite sensors, presently operating in the optical domain, are providing a data se... more Most of the satellite sensors, presently operating in the optical domain, are providing a data set comprising multispectral images at a low spatial resolution and images at a higher spatial resolution but with a lower spectral content. The trend of satellite sensors is similar to the present situation. The idea of fusing multispectral images with a highest spatial resolution enables the creation of useful products for a set of applications. This paper aims at evaluating a set of methods for construction of synthetic multispectral images having a highest spatial resolution available within the data set. These methods are evaluated through the construction of fused products from a set of Quickbird panchromatic and multispectral images. Of interest are the most used methods: the Intensity-Hue-Saturation method, the Brovey transform, the multiplicative methods and a set of methods derived from the ARSIS concept. The different methods are shortly presented. These methods are tested in a dataset from the area of Madrid. The dataset proposed a good diversity of landscape allowing the measure of the impact of fusion methods on different cases. The resulting images are evaluated through visual criteria from a set of photointerpreters. They classified the fused products and pro-vided a ranking for the visual quality. Then the proposed protocol defined by is applied to all methods. A set of quantitative parameters is computed allowing an objective comparison of the results. Finally a new parameter allowing the quantification of the information brought by the fusion method is proposed. This parameter is based on the analysis of the difference of the real structures of a multispectral image and of the computed structures of the fused products. It is applied to the different methods and favors the evaluation of the impact of an algorithm on the resulting images. Some conclusions are drawn on the ranking of the different methods and on the appropriate parameters for the evaluation of the quality of fused products.

This communication deals with the fusion of panchromatic (PAN) images of high spatial resolution ... more This communication deals with the fusion of panchromatic (PAN) images of high spatial resolution and multispectral (MS) images of lower resolution in order to synthesize MS images at high resolution. These fused images should be as identical as possible to images that would have been acquired by the corresponding space borne sensor if it were fit with this high resolution. A protocol for the assessment of the quality of the fused images was discussed by the EARSeL Special Interest Group ''data fusion'' in 2004. It evaluates how much fused images comply with two properties, on multispectral and monospectral viewpoints. The compliance is measured through a set of distances between the set of fused images and the multispectral reference images. This communication analyses the distances that are found in literature. First of all, it proposes a classification of these distances into seven categories. Then it shows some relations between several distances through an empirical study. Finally, a typical choice of distances is proposed in order to assess most aspects of fused images.

Cet article présente les travaux que nous avons menés ces dernières années autour de l'analyse d'... more Cet article présente les travaux que nous avons menés ces dernières années autour de l'analyse d'images Météosat Seconde Génération (MSG). Comparés à la première génération, les données MSG possèdent une résolution spatiale et temporelle plus élevée, autorisant l'accès à un certain nombre d'informations liées aux phénomènes climatiques observés. Cependant, l'étape consistant à remonter à cette information physique à partir des données images s'avère délicate car nous sommes confrontés à des structures soumises à de très fortes déformations, parfois observées en transparence et avec une durée de vie variable. Par conséquent, les outils classiques issus de l'analyse d'images se révèlent souvent limités et il est nécessaire de les adapter à cette spécificité. Nous nous focalisons ici sur trois applications particulières : l'estimation du mouvement, permettant de remonter aux vents atmosphériques, le suivi de masses nuageuses, autorisant par exemple l'analyse de phénomènes convectifs et la détection de fronts, appliquée ici aux brises de mer.

2009 IEEE International Geoscience and Remote Sensing Symposium, 2009

Abstract This paper is interested with the tracking and the analysis of convective cells on Meteo... more Abstract This paper is interested with the tracking and the analysis of convective cells on Meteosat Second Generation images. Due to the highly deformable nature of convective clouds, the noisy measurements obtained with image data and the complexity of the ...

2006 9th International Conference on Information Fusion, 2006

The second objective is to demonstrate that the method may be exploited to assess the geometrical... more The second objective is to demonstrate that the method may be exploited to assess the geometrical quality of the fused product.

2006 9th International Conference on Information Fusion, 2006

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing, 2014

The HelioClim-1 database contains daily values of the solar radiation reaching the ground. This G... more The HelioClim-1 database contains daily values of the solar radiation reaching the ground. This GEOSS (Global Earth Observation System of Systems) Data Collection of Open Resources for Everyone (Data-CORE) covers Europe, Africa and the Atlantic Ocean, from 1985 to 2005. It is freely accessible at no cost through the SoDa Service (www.soda-is.com). Several assessments of the HelioClim-1 data against measurements made in meteorological networks reveal that the HelioClim-1 database offers a reliable and accurate knowledge of the solar radiation and its daily, seasonal and annual variations over recent years. The HelioClim-1 data may help in qualifying in situ measurements and may supplement them, thus offering 21 years of accurate daily means of surface solar irradiance. Several published works benefited from openness, availability and accuracy of the He-lioClim-1 database in various domains: oceanography, climate, energy production, life cycle analysis, agriculture, forestry, architecture, health and air quality. This demonstration of the benefit of the HelioClim-1 database draws attention to resources open to everyone such as those labeled GEOSS Data-CORE.

Journal of Applied Physiology, 2006

Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human pe... more Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human permeabilized muscle fibers. The effects of concurrent hypoxic/endurance training on mitochondrial respiration in permeabilized fibers in trained athletes were investigated. Eighteen endurance athletes were divided into two training groups: normoxic (Nor, n ϭ 8) and hypoxic (H, n ϭ 10). Three weeks (W1-W3) of endurance training (5 sessions of 1 h to 1 h and 30 min per week) were completed. All training sessions were performed under normoxic [160 Torr inspired PO2 (PI O 2 )] or hypoxic conditions (Ϸ100 Torr PI O 2 , Ϸ3,000 m) for Nor and H group, respectively, at the same relative intensity. Before and after the training period, an incremental test to exhaustion in normoxia was performed, muscle biopsy samples were taken from the vastus lateralis, and mitochondrial respiration in permeabilized fibers was measured. Peak power output (PPO) increased by 7.2% and 6.6% (P Ͻ 0.05) for Nor and H, respectively, whereas maximal O2 uptake (V O2 max) remained unchanged: 58.1 Ϯ 0.8 vs. 61.0 Ϯ 1.2 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 and 58.5 Ϯ 0.7 vs. 58.3 Ϯ 0.6 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 for Nor and H, respectively, between pretraining (W0) and posttraining (W4). Maximal ADP-stimulated mitochondrial respiration significantly increased for glutamate ϩ malate (6.27 Ϯ 0.37 vs. 8.51 Ϯ 0.33 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) and significantly decreased for palmitate ϩ malate (3.88 Ϯ 0.23 vs. 2.77 Ϯ 0.08 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) in the H group. In contrast, no significant differences were found for the Nor group. The findings demonstrate that 1) a 3-wk training period increased the PPO at sea level without any changes in V O2 max, and 2) a 3-wk hypoxic exercise training seems to alter the intrinsic properties of mitochondrial function, i.e., substrate preference. endurance exercise; substrate preference; hypoxic stress; aerobic adaptation; muscle biopsy Address for reprint requests and other correspondence: B. Roels, School of Sport and Education, Brunel Univ.,

IEEE Transactions on Geoscience and Remote Sensing, 2000

This paper focuses on the tracking and analysis of convective cloud systems from Meteosat Second ... more This paper focuses on the tracking and analysis of convective cloud systems from Meteosat Second Generation images. The highly deformable nature of convective clouds, the complexity of the physical processes involved, and also the partially hidden measurements available from image data make difficult the direct use of conventional image-analysis techniques for tasks of detection, tracking, and characterization. In this paper, we face these issues using variational-data-assimilation tools. Such techniques enable us to perform the estimation of an unknown state function according to a given dynamical model and to noisy and incomplete measurements. The system state we are setting in this study for the cloud representation is composed of two nested curves corresponding to the exterior frontiers of the clouds and to the interior coldest parts (core) of the convective clouds. Since no reliable simple dynamical model exists for such phenomena at the image grid scale, the dynamics on which we are relying has been directly defined from image-based motion measurements and takes into account an uncertainty modeling of the curve dynamics along time. In addition to this assimilation technique, we show in the Appendix how each cell of the recovered cloud system can be labeled and associated to characteristic parameters (birth or death time, mean temperature, velocity, growth, etc.) of great interest for meteorologists.

IEEE Transactions on Geoscience and Remote Sensing, 2000

Our framework is the synthesis of multispectral images (MS) at higher spatial resolution, which s... more Our framework is the synthesis of multispectral images (MS) at higher spatial resolution, which should be as close as possible to those that would have been acquired by the corresponding sensors if they had this high resolution. This synthesis is performed with the help of a high spatial but low spectral resolution image: the panchromatic (Pan) image. The fusion of the Pan and MS images is classically referred as pan-sharpening. A fused product reaches good quality only if the characteristics and differences between input images are taken into account. Dissimilarities existing between these two data sets originate from two causes-different times and different spectral bands of acquisition. Remote sensing physics should be carefully considered while designing the fusion process. Because of the complexity of physics and the large number of unknowns, authors are led to make assumptions to drive their development. Weaknesses and strengths of each reported method are raised and confronted to these physical constraints. The conclusion of this critical survey of literature is that the choice in the assumptions for the development of a method is crucial, with the risk to drastically weaken fusion performance. It is also shown that the Amélioration de la Résolution Spatiale par Injection de Structures concept prevents from introducing spectral distortion into fused products and offers a reliable framework for further developments.

IEEE Transactions on Geoscience and Remote Sensing, 2000

In January 2006, the Data Fusion Committee of the IEEE Geoscience and Remote Sensing Society laun... more In January 2006, the Data Fusion Committee of the IEEE Geoscience and Remote Sensing Society launched a public contest for pansharpening algorithms, which aimed to identify the ones that perform best. Seven research groups worldwide participated in the contest, testing eight algorithms following different philosophies [component substitution, multiresolution analysis (MRA), detail injection, etc.]. Several complete data sets from two different sensors, namely, QuickBird and simulated Pléiades, were delivered to all participants. The fusion results were collected and evaluated, both visually and objectively. Quantitative results of pansharpening were possible owing to the availability of reference originals obtained either by simulating the data collected from the satellite sensor by means of higher resolution data from an airborne platform, in the case of the Pléiades data, or by first degrading all the available data to a coarser resolution and saving the original as the reference, in the case of the QuickBird data. The evaluation results were presented during the special session on Data Fusion at the 2006 International Geoscience and Remote Sensing Symposium in Denver, and these are discussed in further detail in this paper. Two algorithms outperform all the others, the visual analysis being confirmed by the quantitative evaluation. These two methods share the same philosophy: they basically rely on MRA and employ adaptive models for the injection of high-pass details.

European Journal of Applied Physiology, 2009

The purpose of this study was to examine the relationship between skeletal muscle monocarboxylate... more The purpose of this study was to examine the relationship between skeletal muscle monocarboxylate transporters 1 and 4 (MCT1 and MCT4) expression, skeletal muscle oxidative capacity and endurance performance in trained cyclists. Ten well-trained cyclists (mean ± SD; age 24.4 ± 2.8 years, body mass 73.2 ± 8.3 kg, VO 2max 58 ± 7 ml kg -1 min -1 ) completed three endurance performance tasks [incremental exercise test to exhaustion, 2 and 10 min time trial (TT)]. In addition, a muscle biopsy sample from the vastus lateralis muscle was analysed for MCT1 and MCT4 expression levels together with the activity of citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD). There was a tendency for VO 2max and peak power output obtained in the incremental exercise test to be correlated with MCT1 (r = -0.71 to -0.74; P \ 0.06), but not MCT4. The average power output (P average ) in the 2 min TT was significantly correlated with MCT4 (r = -0.74; P \ 0.05) and HAD (r = -0.92; P \ 0.01). The P average in the 10 min TT was only correlated with CS activity (r = 0.68; P \ 0.05). These results indicate the relationship between MCT1 and MCT4 as well as cycle TT performance may be influenced by the length and intensity of the task.

European Journal of Applied Physiology, 2009

Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposu... more Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposure to hypoxia is suYcient to induce beneWcial muscular adaptations mediated via hypoxia-inducible transcription factors (HIF). We previously demonstrated (Mounier et al. Med Sci Sports Exerc 38:1410-1417) that leukocytes respond to hypoxia with a marked inter-individual variability in HIF-1 mRNA. This study compared the eVects of 3 weeks of intermittent hypoxic training on hif gene expression in both skeletal muscle and leukocytes. Male endurance athletes (n = 19) were divided into an Intermittent Hypoxic Exposure group (IHE) and a Normoxic Training group (NT) with each group following a similar 3-week exercise training program. After training, the amount of HIF-1 mRNA in muscle decreased only in IHE group (¡24.7%, P < 0.05) whereas it remained unchanged in leukocytes in both groups. The levels of vEGF 121 and vEGF 165 mRNA in skeletal muscle increased signiWcantly after training only in the NT group (+82.5%, P < 0.05 for vEGF 121 ; +41.2%, P < 0.05 for vEGF 165 ). In leukocytes, only the IHE group showed a signiWcant change in vEGF 165 (¡28.2%, P < 0.05). The signiWcant decrease in HIF-1 mRNA in skeletal muscle after hypoxic training suggests that transcriptional and post-transcriptional regulations of the hif-1 gene are diVerent in muscle and leukocytes.

BMC Public Health, 2014

Background: Prevention of alcohol, drug and tobacco misuse by young people is a key public health... more Background: Prevention of alcohol, drug and tobacco misuse by young people is a key public health priority. There is a need to develop the evidence base through rigorous evaluations of innovative approaches to substance misuse prevention. The Strengthening Families Programme 10-14 is a universal family-based alcohol, drugs and tobacco prevention programme, which has achieved promising results in US trials, and which now requires cross-cultural assessment. This paper therefore describes the protocol for a randomised controlled trial of the UK version of the Strengthening Families Programme 10-14 (SFP 10-14 UK).

Atmospheric Research, 2003

The National Severe Storms Laboratory (NSSL) has played the primary role in the development and e... more The National Severe Storms Laboratory (NSSL) has played the primary role in the development and evaluation of U.S. National Weather Service (NWS) severe weather applications for the Weather Surveillance Radar-1988 Doppler (WSR-88D). NSSL developed many of the primary detection algorithms for the radar, and is currently developing improvements to these algorithms. The traditional WSR-88D severe weather algorithms have been designed for use with a single-radar data source. Although the algorithm guidance has led to an improvement of the NWS severe weather warning statistics, it is understood that effective warning decisions can only be made via the integration of information from many sources, including input from multiple remote sensors (multiple radars, mesoscale models, satellite, lightning, etc.). Therefore, these traditional single-radar severe weather algorithms have been updated to take advantage of additional data sources in order to reduce the uncertainty of the measurements and increase the accuracy of the diagnoses of severe weather.

Journal of Applied Physiology, 2007

Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human pe... more Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human permeabilized muscle fibers. The effects of concurrent hypoxic/endurance training on mitochondrial respiration in permeabilized fibers in trained athletes were investigated. Eighteen endurance athletes were divided into two training groups: normoxic (Nor, n ϭ 8) and hypoxic (H, n ϭ 10). Three weeks (W1-W3) of endurance training (5 sessions of 1 h to 1 h and 30 min per week) were completed. All training sessions were performed under normoxic [160 Torr inspired PO2 (PI O 2 )] or hypoxic conditions (Ϸ100 Torr PI O 2 , Ϸ3,000 m) for Nor and H group, respectively, at the same relative intensity. Before and after the training period, an incremental test to exhaustion in normoxia was performed, muscle biopsy samples were taken from the vastus lateralis, and mitochondrial respiration in permeabilized fibers was measured. Peak power output (PPO) increased by 7.2% and 6.6% (P Ͻ 0.05) for Nor and H, respectively, whereas maximal O2 uptake (V O2 max) remained unchanged: 58.1 Ϯ 0.8 vs. 61.0 Ϯ 1.2 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 and 58.5 Ϯ 0.7 vs. 58.3 Ϯ 0.6 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 for Nor and H, respectively, between pretraining (W0) and posttraining (W4). Maximal ADP-stimulated mitochondrial respiration significantly increased for glutamate ϩ malate (6.27 Ϯ 0.37 vs. 8.51 Ϯ 0.33 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) and significantly decreased for palmitate ϩ malate (3.88 Ϯ 0.23 vs. 2.77 Ϯ 0.08 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) in the H group. In contrast, no significant differences were found for the Nor group. The findings demonstrate that 1) a 3-wk training period increased the PPO at sea level without any changes in V O2 max, and 2) a 3-wk hypoxic exercise training seems to alter the intrinsic properties of mitochondrial function, i.e., substrate preference. endurance exercise; substrate preference; hypoxic stress; aerobic adaptation; muscle biopsy Address for reprint requests and other correspondence: B. Roels, School of Sport and Education, Brunel Univ.,

European Journal of Applied Physiology, 2009

Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposu... more Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposure to hypoxia is suYcient to induce beneWcial muscular adaptations mediated via hypoxia-inducible transcription factors (HIF). We previously demonstrated (Mounier et al. Med Sci Sports Exerc 38:1410-1417) that leukocytes respond to hypoxia with a marked inter-individual variability in HIF-1 mRNA. This study compared the eVects of 3 weeks of intermittent hypoxic training on hif gene expression in both skeletal muscle and leukocytes. Male endurance athletes (n = 19) were divided into an Intermittent Hypoxic Exposure group (IHE) and a Normoxic Training group (NT) with each group following a similar 3-week exercise training program. After training, the amount of HIF-1 mRNA in muscle decreased only in IHE group (¡24.7%, P < 0.05) whereas it remained unchanged in leukocytes in both groups. The levels of vEGF 121 and vEGF 165 mRNA in skeletal muscle increased signiWcantly after training only in the NT group (+82.5%, P < 0.05 for vEGF 121 ; +41.2%, P < 0.05 for vEGF 165 ). In leukocytes, only the IHE group showed a signiWcant change in vEGF 165 (¡28.2%, P < 0.05). The signiWcant decrease in HIF-1 mRNA in skeletal muscle after hypoxic training suggests that transcriptional and post-transcriptional regulations of the hif-1 gene are diVerent in muscle and leukocytes.

Our work deals with the synthesis of multispectral images at a better spatial resolution by the m... more Our work deals with the synthesis of multispectral images at a better spatial resolution by the means of another image having such a resolution. We show the lack of standard procedure to assess the expected benefits of fused products. We discuss the case of the reference that is missing in most cases. We discuss the principles of the assessment protocol. One principle is that the constructed synthetic images should be close to reality. The second principle is that the fused products should offer a strong consistency with the original data set. This results into two properties of the fused products. We propose a protocol that assesses the quality of fused products with respect to these properties. We define a general framework and the protocol is still open.

Most of the satellite sensors, presently operating in the optical domain, are providing a data se... more Most of the satellite sensors, presently operating in the optical domain, are providing a data set comprising multispectral images at a low spatial resolution and images at a higher spatial resolution but with a lower spectral content. The trend of satellite sensors is similar to the present situation. The idea of fusing multispectral images with a highest spatial resolution enables the creation of useful products for a set of applications. This paper aims at evaluating a set of methods for construction of synthetic multispectral images having a highest spatial resolution available within the data set. These methods are evaluated through the construction of fused products from a set of Quickbird panchromatic and multispectral images. Of interest are the most used methods: the Intensity-Hue-Saturation method, the Brovey transform, the multiplicative methods and a set of methods derived from the ARSIS concept. The different methods are shortly presented. These methods are tested in a dataset from the area of Madrid. The dataset proposed a good diversity of landscape allowing the measure of the impact of fusion methods on different cases. The resulting images are evaluated through visual criteria from a set of photointerpreters. They classified the fused products and pro-vided a ranking for the visual quality. Then the proposed protocol defined by is applied to all methods. A set of quantitative parameters is computed allowing an objective comparison of the results. Finally a new parameter allowing the quantification of the information brought by the fusion method is proposed. This parameter is based on the analysis of the difference of the real structures of a multispectral image and of the computed structures of the fused products. It is applied to the different methods and favors the evaluation of the impact of an algorithm on the resulting images. Some conclusions are drawn on the ranking of the different methods and on the appropriate parameters for the evaluation of the quality of fused products.

This communication deals with the fusion of panchromatic (PAN) images of high spatial resolution ... more This communication deals with the fusion of panchromatic (PAN) images of high spatial resolution and multispectral (MS) images of lower resolution in order to synthesize MS images at high resolution. These fused images should be as identical as possible to images that would have been acquired by the corresponding space borne sensor if it were fit with this high resolution. A protocol for the assessment of the quality of the fused images was discussed by the EARSeL Special Interest Group ''data fusion'' in 2004. It evaluates how much fused images comply with two properties, on multispectral and monospectral viewpoints. The compliance is measured through a set of distances between the set of fused images and the multispectral reference images. This communication analyses the distances that are found in literature. First of all, it proposes a classification of these distances into seven categories. Then it shows some relations between several distances through an empirical study. Finally, a typical choice of distances is proposed in order to assess most aspects of fused images.

Cet article présente les travaux que nous avons menés ces dernières années autour de l'analyse d'... more Cet article présente les travaux que nous avons menés ces dernières années autour de l'analyse d'images Météosat Seconde Génération (MSG). Comparés à la première génération, les données MSG possèdent une résolution spatiale et temporelle plus élevée, autorisant l'accès à un certain nombre d'informations liées aux phénomènes climatiques observés. Cependant, l'étape consistant à remonter à cette information physique à partir des données images s'avère délicate car nous sommes confrontés à des structures soumises à de très fortes déformations, parfois observées en transparence et avec une durée de vie variable. Par conséquent, les outils classiques issus de l'analyse d'images se révèlent souvent limités et il est nécessaire de les adapter à cette spécificité. Nous nous focalisons ici sur trois applications particulières : l'estimation du mouvement, permettant de remonter aux vents atmosphériques, le suivi de masses nuageuses, autorisant par exemple l'analyse de phénomènes convectifs et la détection de fronts, appliquée ici aux brises de mer.

2009 IEEE International Geoscience and Remote Sensing Symposium, 2009

Abstract This paper is interested with the tracking and the analysis of convective cells on Meteo... more Abstract This paper is interested with the tracking and the analysis of convective cells on Meteosat Second Generation images. Due to the highly deformable nature of convective clouds, the noisy measurements obtained with image data and the complexity of the ...

2006 9th International Conference on Information Fusion, 2006

The second objective is to demonstrate that the method may be exploited to assess the geometrical... more The second objective is to demonstrate that the method may be exploited to assess the geometrical quality of the fused product.

2006 9th International Conference on Information Fusion, 2006

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing, 2014

The HelioClim-1 database contains daily values of the solar radiation reaching the ground. This G... more The HelioClim-1 database contains daily values of the solar radiation reaching the ground. This GEOSS (Global Earth Observation System of Systems) Data Collection of Open Resources for Everyone (Data-CORE) covers Europe, Africa and the Atlantic Ocean, from 1985 to 2005. It is freely accessible at no cost through the SoDa Service (www.soda-is.com). Several assessments of the HelioClim-1 data against measurements made in meteorological networks reveal that the HelioClim-1 database offers a reliable and accurate knowledge of the solar radiation and its daily, seasonal and annual variations over recent years. The HelioClim-1 data may help in qualifying in situ measurements and may supplement them, thus offering 21 years of accurate daily means of surface solar irradiance. Several published works benefited from openness, availability and accuracy of the He-lioClim-1 database in various domains: oceanography, climate, energy production, life cycle analysis, agriculture, forestry, architecture, health and air quality. This demonstration of the benefit of the HelioClim-1 database draws attention to resources open to everyone such as those labeled GEOSS Data-CORE.

Journal of Applied Physiology, 2006

Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human pe... more Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human permeabilized muscle fibers. The effects of concurrent hypoxic/endurance training on mitochondrial respiration in permeabilized fibers in trained athletes were investigated. Eighteen endurance athletes were divided into two training groups: normoxic (Nor, n ϭ 8) and hypoxic (H, n ϭ 10). Three weeks (W1-W3) of endurance training (5 sessions of 1 h to 1 h and 30 min per week) were completed. All training sessions were performed under normoxic [160 Torr inspired PO2 (PI O 2 )] or hypoxic conditions (Ϸ100 Torr PI O 2 , Ϸ3,000 m) for Nor and H group, respectively, at the same relative intensity. Before and after the training period, an incremental test to exhaustion in normoxia was performed, muscle biopsy samples were taken from the vastus lateralis, and mitochondrial respiration in permeabilized fibers was measured. Peak power output (PPO) increased by 7.2% and 6.6% (P Ͻ 0.05) for Nor and H, respectively, whereas maximal O2 uptake (V O2 max) remained unchanged: 58.1 Ϯ 0.8 vs. 61.0 Ϯ 1.2 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 and 58.5 Ϯ 0.7 vs. 58.3 Ϯ 0.6 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 for Nor and H, respectively, between pretraining (W0) and posttraining (W4). Maximal ADP-stimulated mitochondrial respiration significantly increased for glutamate ϩ malate (6.27 Ϯ 0.37 vs. 8.51 Ϯ 0.33 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) and significantly decreased for palmitate ϩ malate (3.88 Ϯ 0.23 vs. 2.77 Ϯ 0.08 mol O2 ⅐ min Ϫ1 ⅐ g dry weight Ϫ1 ) in the H group. In contrast, no significant differences were found for the Nor group. The findings demonstrate that 1) a 3-wk training period increased the PPO at sea level without any changes in V O2 max, and 2) a 3-wk hypoxic exercise training seems to alter the intrinsic properties of mitochondrial function, i.e., substrate preference. endurance exercise; substrate preference; hypoxic stress; aerobic adaptation; muscle biopsy Address for reprint requests and other correspondence: B. Roels, School of Sport and Education, Brunel Univ.,

IEEE Transactions on Geoscience and Remote Sensing, 2000

This paper focuses on the tracking and analysis of convective cloud systems from Meteosat Second ... more This paper focuses on the tracking and analysis of convective cloud systems from Meteosat Second Generation images. The highly deformable nature of convective clouds, the complexity of the physical processes involved, and also the partially hidden measurements available from image data make difficult the direct use of conventional image-analysis techniques for tasks of detection, tracking, and characterization. In this paper, we face these issues using variational-data-assimilation tools. Such techniques enable us to perform the estimation of an unknown state function according to a given dynamical model and to noisy and incomplete measurements. The system state we are setting in this study for the cloud representation is composed of two nested curves corresponding to the exterior frontiers of the clouds and to the interior coldest parts (core) of the convective clouds. Since no reliable simple dynamical model exists for such phenomena at the image grid scale, the dynamics on which we are relying has been directly defined from image-based motion measurements and takes into account an uncertainty modeling of the curve dynamics along time. In addition to this assimilation technique, we show in the Appendix how each cell of the recovered cloud system can be labeled and associated to characteristic parameters (birth or death time, mean temperature, velocity, growth, etc.) of great interest for meteorologists.

IEEE Transactions on Geoscience and Remote Sensing, 2000

Our framework is the synthesis of multispectral images (MS) at higher spatial resolution, which s... more Our framework is the synthesis of multispectral images (MS) at higher spatial resolution, which should be as close as possible to those that would have been acquired by the corresponding sensors if they had this high resolution. This synthesis is performed with the help of a high spatial but low spectral resolution image: the panchromatic (Pan) image. The fusion of the Pan and MS images is classically referred as pan-sharpening. A fused product reaches good quality only if the characteristics and differences between input images are taken into account. Dissimilarities existing between these two data sets originate from two causes-different times and different spectral bands of acquisition. Remote sensing physics should be carefully considered while designing the fusion process. Because of the complexity of physics and the large number of unknowns, authors are led to make assumptions to drive their development. Weaknesses and strengths of each reported method are raised and confronted to these physical constraints. The conclusion of this critical survey of literature is that the choice in the assumptions for the development of a method is crucial, with the risk to drastically weaken fusion performance. It is also shown that the Amélioration de la Résolution Spatiale par Injection de Structures concept prevents from introducing spectral distortion into fused products and offers a reliable framework for further developments.

IEEE Transactions on Geoscience and Remote Sensing, 2000

In January 2006, the Data Fusion Committee of the IEEE Geoscience and Remote Sensing Society laun... more In January 2006, the Data Fusion Committee of the IEEE Geoscience and Remote Sensing Society launched a public contest for pansharpening algorithms, which aimed to identify the ones that perform best. Seven research groups worldwide participated in the contest, testing eight algorithms following different philosophies [component substitution, multiresolution analysis (MRA), detail injection, etc.]. Several complete data sets from two different sensors, namely, QuickBird and simulated Pléiades, were delivered to all participants. The fusion results were collected and evaluated, both visually and objectively. Quantitative results of pansharpening were possible owing to the availability of reference originals obtained either by simulating the data collected from the satellite sensor by means of higher resolution data from an airborne platform, in the case of the Pléiades data, or by first degrading all the available data to a coarser resolution and saving the original as the reference, in the case of the QuickBird data. The evaluation results were presented during the special session on Data Fusion at the 2006 International Geoscience and Remote Sensing Symposium in Denver, and these are discussed in further detail in this paper. Two algorithms outperform all the others, the visual analysis being confirmed by the quantitative evaluation. These two methods share the same philosophy: they basically rely on MRA and employ adaptive models for the injection of high-pass details.

European Journal of Applied Physiology, 2009

The purpose of this study was to examine the relationship between skeletal muscle monocarboxylate... more The purpose of this study was to examine the relationship between skeletal muscle monocarboxylate transporters 1 and 4 (MCT1 and MCT4) expression, skeletal muscle oxidative capacity and endurance performance in trained cyclists. Ten well-trained cyclists (mean ± SD; age 24.4 ± 2.8 years, body mass 73.2 ± 8.3 kg, VO 2max 58 ± 7 ml kg -1 min -1 ) completed three endurance performance tasks [incremental exercise test to exhaustion, 2 and 10 min time trial (TT)]. In addition, a muscle biopsy sample from the vastus lateralis muscle was analysed for MCT1 and MCT4 expression levels together with the activity of citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD). There was a tendency for VO 2max and peak power output obtained in the incremental exercise test to be correlated with MCT1 (r = -0.71 to -0.74; P \ 0.06), but not MCT4. The average power output (P average ) in the 2 min TT was significantly correlated with MCT4 (r = -0.74; P \ 0.05) and HAD (r = -0.92; P \ 0.01). The P average in the 10 min TT was only correlated with CS activity (r = 0.68; P \ 0.05). These results indicate the relationship between MCT1 and MCT4 as well as cycle TT performance may be influenced by the length and intensity of the task.

European Journal of Applied Physiology, 2009

Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposu... more Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposure to hypoxia is suYcient to induce beneWcial muscular adaptations mediated via hypoxia-inducible transcription factors (HIF). We previously demonstrated (Mounier et al. Med Sci Sports Exerc 38:1410-1417) that leukocytes respond to hypoxia with a marked inter-individual variability in HIF-1 mRNA. This study compared the eVects of 3 weeks of intermittent hypoxic training on hif gene expression in both skeletal muscle and leukocytes. Male endurance athletes (n = 19) were divided into an Intermittent Hypoxic Exposure group (IHE) and a Normoxic Training group (NT) with each group following a similar 3-week exercise training program. After training, the amount of HIF-1 mRNA in muscle decreased only in IHE group (¡24.7%, P < 0.05) whereas it remained unchanged in leukocytes in both groups. The levels of vEGF 121 and vEGF 165 mRNA in skeletal muscle increased signiWcantly after training only in the NT group (+82.5%, P < 0.05 for vEGF 121 ; +41.2%, P < 0.05 for vEGF 165 ). In leukocytes, only the IHE group showed a signiWcant change in vEGF 165 (¡28.2%, P < 0.05). The signiWcant decrease in HIF-1 mRNA in skeletal muscle after hypoxic training suggests that transcriptional and post-transcriptional regulations of the hif-1 gene are diVerent in muscle and leukocytes.

BMC Public Health, 2014

Background: Prevention of alcohol, drug and tobacco misuse by young people is a key public health... more Background: Prevention of alcohol, drug and tobacco misuse by young people is a key public health priority. There is a need to develop the evidence base through rigorous evaluations of innovative approaches to substance misuse prevention. The Strengthening Families Programme 10-14 is a universal family-based alcohol, drugs and tobacco prevention programme, which has achieved promising results in US trials, and which now requires cross-cultural assessment. This paper therefore describes the protocol for a randomised controlled trial of the UK version of the Strengthening Families Programme 10-14 (SFP 10-14 UK).

Atmospheric Research, 2003

The National Severe Storms Laboratory (NSSL) has played the primary role in the development and e... more The National Severe Storms Laboratory (NSSL) has played the primary role in the development and evaluation of U.S. National Weather Service (NWS) severe weather applications for the Weather Surveillance Radar-1988 Doppler (WSR-88D). NSSL developed many of the primary detection algorithms for the radar, and is currently developing improvements to these algorithms. The traditional WSR-88D severe weather algorithms have been designed for use with a single-radar data source. Although the algorithm guidance has led to an improvement of the NWS severe weather warning statistics, it is understood that effective warning decisions can only be made via the integration of information from many sources, including input from multiple remote sensors (multiple radars, mesoscale models, satellite, lightning, etc.). Therefore, these traditional single-radar severe weather algorithms have been updated to take advantage of additional data sources in order to reduce the uncertainty of the measurements and increase the accuracy of the diagnoses of severe weather.