Interpolation-free Coregistration and Phase-Correction of Airborne SAR Interferograms

This letter discusses the detection and correction ofresidual motion errors that appear in airborne synthetic apertureradar (SAR) interferograms due to the lack of precision in the navigationsystem. As it is shown, the effect of this lack of precision istwofold: azimuth registration errors and phase azimuth undulations.Up to now, the correction of the former was carried out byestimating the registration error and interpolating, while the latterwas based on the estimation of the phase azimuth undulations tocompensate the phase of the computed interferogram. In this letter,a new correction method is proposed, which avoids the interpolationstep and corrects at the same time the azimuth phase undulations.Additionally, the spectral diversity technique, used to estimateregistration errors, is critically analyzed. Airborne L-bandrepeat-pass interferometric data of the German Aerospace Center(DLR) experimental airborne SAR is used to validate the method

Maximum-likelihood estimation of specific differential phase and attenuation in rain

Precise estimation of propagation parameters inprecipitation media is of interest to improve the performanceof communications systems and in remote sensing applications.In this paper, we present maximum-likelihood estimators ofspecific attenuation and specific differential phase in rain. Themodel used for obtaining the cited estimators assumes coherentpropagation, reflection symmetry of the medium, and Gaussianstatistics of the scattering matrix measurements. No assumptionsabout the microphysical properties of the medium are needed.The performance of the estimators is evaluated through simulateddata. Results show negligible estimators bias and variances closeto Cramer–Rao bounds.

RNOP-09: pegylated liposomal doxorubicine and prolonged temozolomide in addition to radiotherapy in newly diagnosed glioblastoma--a phase II study.

BACKGROUND: Although Temozolomide is effective against glioblastoma, the prognosis remains dismal and new regimens with synergistic activity are sought for. METHODS: In this phase-I/II trial, pegylated liposomal doxorubicin (Caelyx, PEG-Dox) and prolonged administration of Temozolomide in addition to radiotherapy was investigated in 63 patients with newly diagnosed glioblastoma. In phase-I, PEG-Dox was administered in a 3-by-3 dose-escalation regimen. In phase-II, 20 mg/m2 PEG-Dox was given once prior to radiotherapy and on days 1 and 15 of each 28-day cycle starting 4 weeks after radiotherapy. Temozolomide was given in a dose of 75 mg/m2 daily during radiotherapy (60 Gy) and 150-200 mg/m2 on days 1-5 of each 28-day cycle for 12 cycles or until disease progression. RESULTS: The toxicity of the combination of PEG-Dox, prolonged administration of Temozolomide, and radiotherapy was tolerable. The progression free survival after 12 months (PFS-12) was 30.2%, the median overall survival was 17.6 months in all patients including the ones from Phase-I. None of the endpoints differed significantly from the EORTC26981/NCIC-CE.3 data in a post-hoc statistical comparison. CONCLUSION: Together, the investigated combination is tolerable and feasible. Neither the addition of PEG-Dox nor the prolonged administration of Temozolomide resulted in a meaningful improvement of the patient's outcome as compared to the EORTC26981/NCIC-CE.3 data.

Psychological needs of adolescents in the early phase of bipolar disorder: implications for early intervention.

Aim: This paper will describe the rationale for, and importance of, psychological interventions for young people early in the course of bipolar disorder. Methods: Emerging literature in this field will be discussed in addition to describing specific clinical challenges and opportunities with this population. Results: In order to be more developmentally appropriate for young people with bipolar disorder, eight aspects of clinical work which may require modification were identified. Conclusions: The evidence base for the effectiveness of psychological interventions for people diagnosed with bipolar disorder is growing. However, some aspects relating to working with adults with bipolar disorder require modification to be effective in working with young people early in the course of the disorder.

5-Azacytidine to Treat Acute Myeloid Leukemia In Elderly or Frail Patients: A Phase II Study (SAKK 30/07).

Background: Acute Myeloid Leukemia (AML) in the elderly is notoriously difficult to treat and has a low remission rate with very few long term survivors when using standard treatment approaches. Azacytidine, a hypomethylating agent, has been shown to induce remission and prolong survival in patients with myelodysplastic syndromes; studying this approach to patients with AML is therefore warranted. We present results of an ongoing phase II trial treating elderly or frail AML patients with Azacytidine. Methods: AML elderly or frail patients, and therefore unfit for an intensive chemotherapy regimens, with a WHO performance status 3 were considered for this trial. Trial therapy consisted of 100mg/m2 of Azacytidine injected subcutaneously on 5 consecutive days every 28 days up to 6 cycles, stopping at 6 months if no hematological improvement achieved, or earlier in the case of progression or complications. Treatment was continued beyond 6 months in responding patients. Trial therapy was considered uninteresting if the response rate (CR + PR) within 6 months of therapy initiation was 15% or less and promising if 34% or more. Using the exact single-stage phase II design by A'Hern with a 5% significance level and 90% power, 43 patients were required: If 10 or fewer achieved a response within 6 months the trial therapy should not be considered for further investigation in its current format for this indication and patient population. Results: Between September 2008 and January 2010, 45 evaluable patients across 10 Swiss centers were accrued with a median follow-up of 7 months (range: 0 - 13). 27 (60%) were male, median age was 74 (range: 55 - 86) years and 35 (78.8%) had performance status 0-1. Patients had been excluded from more intensive chemotherapy regimens because of age (n = 37) or due to comorbidities or patient refusal (n=8). Five patients had therapy related AML. Patients received a median of 3 (range: 1 - 10) cycles. Treatment was stopped for not achieving a response by the 6th cycle in 2 patients and earlier in 26 patients (for disease progression in 5, toxicity in 3, patient refusal in 2, recurrent infections in 1, and death in 8). Seventeen patients remain on therapy. The median time spent in the hospital was 12 days (1 - 30) in 24/38 patients hospitalized during the first treatment cycle and 13 days (2 - 28) in 15/31 patients hospitalized during subsequent cycles. Adverse events of grade III or higher most frequently reported were constitutional or hematologic, i.e. fatigue in 5, febrile neutropenia in 8, infections in 6, dyspnea in 6, anemia in 3, neutropenia in 12 and thrombocytopenia in 10, hemorrhage in 2 and retinal detachment in 5. Based on available data on 38 patients, CR/CRi or hematologic improvement or stable disease within 6 months of trial registration was observed in a proportion of patients. Final and mature data, determining whether the predefined proportion of responding patients has been reached or not, will be presented at the conference. Up to now there were a total of 26 deaths. Median overall survival time was 5.7 months (95% CI: 3.1, 8.7). Conclusions: The current results of this slightly modified Azacytidine schedule demonstrate a feasible new therapy option for elderly or frail AML patients in an outpatient setting with moderate, mainly hematologic toxicity.

Canakinumab for the treatment of acute flares in difficult-to-treat gouty arthritis: Results of a multicenter, phase II, dose-ranging study.

OBJECTIVE: To assess the efficacy and tolerability of canakinumab, a fully human anti-interleukin-1β monoclonal antibody, for the treatment of acute gouty arthritis. METHODS: In this 8-week, single-blind, double-dummy, dose-ranging study, patients with acute gouty arthritis whose disease was refractory to or who had contraindications to nonsteroidal antiinflammatory drugs and/or colchicine were randomized to receive a single subcutaneous dose of canakinumab (10, 25, 50, 90, or 150 mg; n = 143) or an intramuscular dose of triamcinolone acetonide (40 mg; n = 57). Patients assessed pain using a 100-mm visual analog scale. RESULTS: Seventy-two hours after treatment, a statistically significant dose response was observed for canakinumab. All canakinumab doses were associated with numerically less pain than triamcinolone acetonide; thus, a dose with equivalent efficacy to triamcinolone acetonide 72 hours after treatment could not be determined. The reduction from baseline in pain intensity with canakinumab 150 mg was greater than with triamcinolone acetonide 24, 48, and 72 hours after treatment (differences of -11.5 mm [P = 0.04], -18.2 mm [P = 0.002], and -19.2 mm [P < 0.001], respectively), and 4, 5, and 7 days after treatment (all P < 0.05). Canakinumab significantly reduced the risk of recurrent flares versus triamcinolone acetonide (P ≤ 0.01 for all doses) (relative risk reduction 94% for canakinumab 150 mg versus triamcinolone acetonide). The overall incidence of adverse events was similar for canakinumab (41%) and triamcinolone acetonide (42%); most were mild or moderate in severity. CONCLUSION: Our findings indicate that canakinumab 150 mg provides rapid and sustained pain relief in patients with acute gouty arthritis, and significantly reduces the risk of recurrent flares compared with triamcinolone acetonide.

Positive contrast MR-lymphography using inversion recovery with ON-resonant water suppression (IRON).

PURPOSE: To investigate the utility of inversion recovery with ON-resonant water suppression (IRON) to create positive signal in normal lymph nodes after injection of superparamagnetic nanoparticles. MATERIALS AND METHODS: Experiments were conducted on six rabbits, which received a single bolus injection of 80 mumol Fe/kg monocrystalline iron oxide nanoparticle (MION-47). Magnetic resonance imaging (MRI) was performed at baseline, 1 day, and 3 days after MION-47 injection using conventional T(1)- and T(2)*-weighted sequences and IRON. Contrast-to-noise ratios (CNR) were measured in blood and in paraaortic lymph nodes. RESULTS: On T(2)*-weighted images, as expected, signal attenuation was observed in areas of paraaortic lymph nodes after MION-47 injection. However, using IRON the paraaortic lymph nodes exhibited very high contrast enhancement, which remained 3 days after injection. CNR with IRON was 2.2 +/- 0.8 at baseline, increased markedly 1 day after injection (23.5 +/- 5.4, P < 0.01 vs. baseline), and remained high after 3 days (21.8 +/- 5.7, *P < 0.01 vs. baseline). CNR was also high in blood 1 day after injection (42.7 +/- 7.2 vs. 1.8 +/- 0.7 at baseline, P < 0.01) but approached baseline after 3 days (1.9 +/- 1.4, P = NS vs. baseline). CONCLUSION: IRON in conjunction with superparamagnetic nanoparticles can be used to perform 'positive contrast' MR-lymphography, particularly 3 days after injection of the contrast agent, when signal is no longer visible within blood vessels. The proposed method may have potential as an adjunct for nodal staging in cancer screening.

The synthetic Plasmodium falciparum circumsporozoite peptide PfCS102 as a malaria vaccine candidate: a randomized controlled phase I trial.

BACKGROUND: Fully efficient vaccines against malaria pre-erythrocytic stage are still lacking. The objective of this dose/adjuvant-finding study was to evaluate the safety, reactogenicity and immunogenicity of a vaccine candidate based on a peptide spanning the C-terminal region of Plasmodium falciparum circumsporozoite protein (PfCS102) in malaria naive adults. METHODOLOGY AND PRINCIPAL FINDINGS: Thirty-six healthy malaria-naive adults were randomly distributed into three dose blocks (10, 30 and 100 microg) and vaccinated with PfCS102 in combination with either Montanide ISA 720 or GSK proprietary Adjuvant System AS02A at days 0, 60, and 180. Primary end-point (safety and reactogenicity) was based on the frequency of adverse events (AE) and of abnormal biological safety tests; secondary-end point (immunogenicity) on P. falciparum specific cell-mediated immunity and antibody response before and after immunization. The two adjuvant formulations were well tolerated and their safety profile was good. Most AEs were local and, when systemic, involved mainly fatigue and headache. Half the volunteers in AS02A groups experienced severe AEs (mainly erythema). After the third injection, 34 of 35 volunteers developed anti-PfCS102 and anti-sporozoite antibodies, and 28 of 35 demonstrated T-cell proliferative responses and IFN-gamma production. Five of 22 HLA-A2 and HLA-A3 volunteers displayed PfCS102 specific IFN-gamma secreting CD8(+) T cell responses. Responses were only marginally boosted after the 3(rd) vaccination and remained stable for 6 months. For both adjuvants, the dose of 10 microg was less immunogenic in comparison to 30 and 100 microg that induced similar responses. AS02A formulations with 30 microg or 100 microg PfCS102 induced about 10-folds higher antibody and IFN-gamma responses than Montanide formulations. CONCLUSIONS/SIGNIFICANCE: PfCS102 peptide was safe and highly immunogenic, allowing the design of more advanced trials to test its potential for protection. Two or three immunizations with a dose of 30 microg formulated with AS02A appeared the most appropriate choice for such studies. TRIAL REGISTRATION: Swissmedic.ch 2002 DR 1227.

A phase 2 randomized trial of radiotherapy (RT) plus panitumumab compared to chemoradiotherapy in patients with unresected, locally advanced squamous cell carcinoma of the head and neck (SCCHN): interim pooled safety analysis

Background: Panitumumab (pmab), a fully human monoclonal antibody against the epidermal growth factor receptor (EGFR), is indicated as monotherapy for treatment of metastatic colorectal cancer. This ongoing study is designed to assess the efficacy and safety of pmab in combination with radiotherapy (PRT) compared to chemoradiotherapy (CRT) as initial treatment of unresected, locally advanced SCCHN (ClinicalTrials.gov Identifier: NCT00547157). Methods: This is a phase 2, open-label, randomized, multicenter study. Eligible patients (pts) were randomized 2:3 to receive cisplatin 100 mg/m2 on days 1 and 22 of RT or pmab 9.0 mg/kg on days 1, 22, and 43. Accelerated RT (70 to 72 Gy − delivered over 6 to 6.5 weeks) was planned for all pts and was delivered either by intensity-modulated radiation therapy (IMRT) modality or by three-dimensional conformal (3D-CRT) modality. The primary endpoint is local-regional control (LRC) rate at 2 years. Key secondary endpoints include PFS, OS, and safety. An external, independent data monitoring committee conducts planned safety and efficacy reviews during the course of the trial. Results: Pooled data from this planned interim safety analysis includes the first 52 of the 150 planned pts; 44 (84.6%) are male; median (range) age is 57 (33−77) years; ECOG PS 0: 65%, PS 1: 35%; 20 (39%) pts received IMRT, and 32 (61%) pts received 3D-CRT. Fifty (96%) pts completed RT, and 50 pts received RT per protocol without a major deviation. The median (range) total RT dose administered was 72 (64−74) Gy. The most common grade _ 3 adverse events graded using the CTCAE version 3.0 are shown (Table). Conclusions: After the interim safety analysis, CONCERT-2 continues per protocol. Study enrollment is estimated to be completed by October 2009.

Comment commencer l'entretien médical ? Réflexions sur la phase sociale à partir d'enregistrements vidéo [How do we begin a medical interview? Reflections from videotapes]

L'entrevue médicale est constituée de plusieurs étapes, chacune d'entre elles comprenant des tâches et des objectifs particuliers pour le médecin. La partie initiale de la consultation médicale, la phase sociale, constitue la première pierre dans la construction d'une relation médecin-patient de confiance et de qualité. Si, d'un point de vue structurel, la littérature a répondu de façon claire et concordante, des questions demeurent ouvertes d'un point de vue procédural. De quelle manière le médecin parvient-il à établir le premier contact ? Comment procède-t-il pour accueillir son patient ? Des pistes pour répondre à ces questions se repèrent dans le travail de révision des enregistrements vidéo des consultations de médecine générale qui sont régulièrement pratiqués à la Policlinique médicale universitaire (PMU) de Lausanne. [Auteurs] The medical interview consists of several steps, each consisting of specific tasks and objectives for the doctor. The initial step of the medical consultation, the social phase, is the cornerstone in the construction of a doctor-patient relationship of trust and quality. If, in a structural point of view, the literature has responded in a clear and consistent way, questions remain openned in a procedural point of view. How successful is the physician to establish the first contact? How does he proceed to welcome his patient? We looked out ways to address these issues by the work of revising the video recordings of general medical consultations, which are regularly practiced at the Medical outpatient clinic of the University of Lausanne.

RF pulse concatenation for spatially selective inversion

It is shown that spatially selective inversion and saturation can be achieved by concatenation of RF pulses with lower flip angles. A concatenation rule which enables global doubling of the flip angle of any given excitation pulse applied to initial z magnetization is proposed. In this fashion, the selectivity of the single pulse is preserved, making the high selectivity achievable in the low flip-angle regime available for inversion and large flip-angle saturation purposes. The profile quality achievable with exemplary concatenated pulses is investigated in comparison with adiabatic inversion. It is verified that by using concatenated inversion in the transfer insensitive labeling technique (TILT), the MT artifact is suppressed. Copyright 2000 Academic Press.

Kitcher's Revolutionary Reasoning Inversion in Ethics

This paper examines three specific issues raised by The Ethical Project. First, I discuss the varieties of altruism and spell out the differences between the definitions proposed by Kitcher and the ways altruism is usually conceived in biology, philosophy, psychology, and economics literature. Second, with the example of Kitcher's account, I take a critical look at evolutionary stories of the emergence of human ethical practices. Third, I point to the revolutionary implications of the Darwinian methodology when it is thoughtfully applied to ethics.

Cetuximab in combination with chemoradiotherapy prior to surgery in patients with resectable, locally advanced esophageal carcinoma : a prospective, multicenter phase lb-ll trial of the Swiss Group for Clinical Cancer Research (SAKK 75/06) : 4570

Background: Cetuximab significantly enhances efficacy of radiotherapy and chemotherapy in head and neck cancer. We investigated the safety and feasibility of adding cetuximab to neoadjuvant chemoradiation of locally advanced esophageal cancer. Methods: Pts with resectable, locally advanced squamous cell carcinoma (SCC) or adenocarcinoma (AC) of the thoracic esophagus or gastroesophageal junction (staged by EUS, CT and PET scan) were treated with 2 cycles of induction chemotherapy (docetaxel 75mg/m2, cisplatin 75mg/m2 q3w and weekly cetuximab 250mg/m2), followed by concomitant chemo- immuno-radiation therapy (CIRT: docetaxel 20mg/m2, cisplatin 25mg/m2 and cetuximab 250mg/m2 weekly five times concomitant with 45 Gy radiotherapy in 25 fractions); followed by surgery 4-8 weeks later. The phase I part consisted of 2 cohorts of 7 patients each, without and with docetaxel during CIRT, respectively. Interpatient dose-escalation (adding docetaxel during CIRT) was possible if < 2 out of 7 pts of the 1st cohort experienced limiting toxicity. Having finished the phase 1 part, 13 additional patients were treated with docetaxel-containing CIRT in a phase II part. Pathological response was evaluated according to the Mandard classification. Results: 27 pts from 12 institutions were included. As of today, results from 20 pts are available (cohort 1: 7, cohort 2: 7, phase ll : 6). Median age was 64yrs (range 47-71). 11 AC; 9 SCC. 19 pts (95%) completed CIRT (1 pt stopped treatment during induction therapy due to sepsis). 17 pts underwent resection (no surgery: 1pt for PD, 1pt for cardiac reasons). Grade 3 toxicities during CIRT included anorexia 15%, dysphagia/esophagitis 15%, fatigue 10%, nausea 10%, pruritus 5%, dehydration 5%, nail changes 5% and rash 5% .1 pt suffered from pulmonary embolism. 13 pts (65%, intention-to-treat) showed a complete or near complete pathological remission (cohort 1: 5, cohort 2: 4, phase II: 4). Conclusions: Adding cetuximab to preoperative chemoradiation for esophageal cancer is safe and feasible in a community-based multicenter setting. Antineoplastic activity is encouraging with 65% pathological responders.

Time-lapse and probabilistic inversion strategies for plane-wave electromagnetic data.

L'utilisation efficace des systèmes géothermaux, la séquestration du CO2 pour limiter le changement climatique et la prévention de l'intrusion d'eau salée dans les aquifères costaux ne sont que quelques exemples qui démontrent notre besoin en technologies nouvelles pour suivre l'évolution des processus souterrains à partir de la surface. Un défi majeur est d'assurer la caractérisation et l'optimisation des performances de ces technologies à différentes échelles spatiales et temporelles. Les méthodes électromagnétiques (EM) d'ondes planes sont sensibles à la conductivité électrique du sous-sol et, par conséquent, à la conductivité électrique des fluides saturant la roche, à la présence de fractures connectées, à la température et aux matériaux géologiques. Ces méthodes sont régies par des équations valides sur de larges gammes de fréquences, permettant détudier de manières analogues des processus allant de quelques mètres sous la surface jusqu'à plusieurs kilomètres de profondeur. Néanmoins, ces méthodes sont soumises à une perte de résolution avec la profondeur à cause des propriétés diffusives du champ électromagnétique. Pour cette raison, l'estimation des modèles du sous-sol par ces méthodes doit prendre en compte des informations a priori afin de contraindre les modèles autant que possible et de permettre la quantification des incertitudes de ces modèles de façon appropriée. Dans la présente thèse, je développe des approches permettant la caractérisation statique et dynamique du sous-sol à l'aide d'ondes EM planes. Dans une première partie, je présente une approche déterministe permettant de réaliser des inversions répétées dans le temps (time-lapse) de données d'ondes EM planes en deux dimensions. Cette stratégie est basée sur l'incorporation dans l'algorithme d'informations a priori en fonction des changements du modèle de conductivité électrique attendus. Ceci est réalisé en intégrant une régularisation stochastique et des contraintes flexibles par rapport à la gamme des changements attendus en utilisant les multiplicateurs de Lagrange. J'utilise des normes différentes de la norme l2 pour contraindre la structure du modèle et obtenir des transitions abruptes entre les régions du model qui subissent des changements dans le temps et celles qui n'en subissent pas. Aussi, j'incorpore une stratégie afin d'éliminer les erreurs systématiques de données time-lapse. Ce travail a mis en évidence l'amélioration de la caractérisation des changements temporels par rapport aux approches classiques qui réalisent des inversions indépendantes à chaque pas de temps et comparent les modèles. Dans la seconde partie de cette thèse, j'adopte un formalisme bayésien et je teste la possibilité de quantifier les incertitudes sur les paramètres du modèle dans l'inversion d'ondes EM planes. Pour ce faire, je présente une stratégie d'inversion probabiliste basée sur des pixels à deux dimensions pour des inversions de données d'ondes EM planes et de tomographies de résistivité électrique (ERT) séparées et jointes. Je compare les incertitudes des paramètres du modèle en considérant différents types d'information a priori sur la structure du modèle et différentes fonctions de vraisemblance pour décrire les erreurs sur les données. Les résultats indiquent que la régularisation du modèle est nécessaire lorsqu'on a à faire à un large nombre de paramètres car cela permet d'accélérer la convergence des chaînes et d'obtenir des modèles plus réalistes. Cependent, ces contraintes mènent à des incertitudes d'estimations plus faibles, ce qui implique des distributions a posteriori qui ne contiennent pas le vrai modèledans les régions ou` la méthode présente une sensibilité limitée. Cette situation peut être améliorée en combinant des méthodes d'ondes EM planes avec d'autres méthodes complémentaires telles que l'ERT. De plus, je montre que le poids de régularisation des paramètres et l'écart-type des erreurs sur les données peuvent être retrouvés par une inversion probabiliste. Finalement, j'évalue la possibilité de caractériser une distribution tridimensionnelle d'un panache de traceur salin injecté dans le sous-sol en réalisant une inversion probabiliste time-lapse tridimensionnelle d'ondes EM planes. Etant donné que les inversions probabilistes sont très coûteuses en temps de calcul lorsque l'espace des paramètres présente une grande dimension, je propose une stratégie de réduction du modèle ou` les coefficients de décomposition des moments de Legendre du panache de traceur injecté ainsi que sa position sont estimés. Pour ce faire, un modèle de résistivité de base est nécessaire. Il peut être obtenu avant l'expérience time-lapse. Un test synthétique montre que la méthodologie marche bien quand le modèle de résistivité de base est caractérisé correctement. Cette méthodologie est aussi appliquée à un test de trac¸age par injection d'une solution saline et d'acides réalisé dans un système géothermal en Australie, puis comparée à une inversion time-lapse tridimensionnelle réalisée selon une approche déterministe. L'inversion probabiliste permet de mieux contraindre le panache du traceur salin gr^ace à la grande quantité d'informations a priori incluse dans l'algorithme. Néanmoins, les changements de conductivités nécessaires pour expliquer les changements observés dans les données sont plus grands que ce qu'expliquent notre connaissance actuelle des phénomenès physiques. Ce problème peut être lié à la qualité limitée du modèle de résistivité de base utilisé, indiquant ainsi que des efforts plus grands devront être fournis dans le futur pour obtenir des modèles de base de bonne qualité avant de réaliser des expériences dynamiques. Les études décrites dans cette thèse montrent que les méthodes d'ondes EM planes sont très utiles pour caractériser et suivre les variations temporelles du sous-sol sur de larges échelles. Les présentes approches améliorent l'évaluation des modèles obtenus, autant en termes d'incorporation d'informations a priori, qu'en termes de quantification d'incertitudes a posteriori. De plus, les stratégies développées peuvent être appliquées à d'autres méthodes géophysiques, et offrent une grande flexibilité pour l'incorporation d'informations additionnelles lorsqu'elles sont disponibles. -- The efficient use of geothermal systems, the sequestration of CO2 to mitigate climate change, and the prevention of seawater intrusion in coastal aquifers are only some examples that demonstrate the need for novel technologies to monitor subsurface processes from the surface. A main challenge is to assure optimal performance of such technologies at different temporal and spatial scales. Plane-wave electromagnetic (EM) methods are sensitive to subsurface electrical conductivity and consequently to fluid conductivity, fracture connectivity, temperature, and rock mineralogy. These methods have governing equations that are the same over a large range of frequencies, thus allowing to study in an analogous manner processes on scales ranging from few meters close to the surface down to several hundreds of kilometers depth. Unfortunately, they suffer from a significant resolution loss with depth due to the diffusive nature of the electromagnetic fields. Therefore, estimations of subsurface models that use these methods should incorporate a priori information to better constrain the models, and provide appropriate measures of model uncertainty. During my thesis, I have developed approaches to improve the static and dynamic characterization of the subsurface with plane-wave EM methods. In the first part of this thesis, I present a two-dimensional deterministic approach to perform time-lapse inversion of plane-wave EM data. The strategy is based on the incorporation of prior information into the inversion algorithm regarding the expected temporal changes in electrical conductivity. This is done by incorporating a flexible stochastic regularization and constraints regarding the expected ranges of the changes by using Lagrange multipliers. I use non-l2 norms to penalize the model update in order to obtain sharp transitions between regions that experience temporal changes and regions that do not. I also incorporate a time-lapse differencing strategy to remove systematic errors in the time-lapse inversion. This work presents improvements in the characterization of temporal changes with respect to the classical approach of performing separate inversions and computing differences between the models. In the second part of this thesis, I adopt a Bayesian framework and use Markov chain Monte Carlo (MCMC) simulations to quantify model parameter uncertainty in plane-wave EM inversion. For this purpose, I present a two-dimensional pixel-based probabilistic inversion strategy for separate and joint inversions of plane-wave EM and electrical resistivity tomography (ERT) data. I compare the uncertainties of the model parameters when considering different types of prior information on the model structure and different likelihood functions to describe the data errors. The results indicate that model regularization is necessary when dealing with a large number of model parameters because it helps to accelerate the convergence of the chains and leads to more realistic models. These constraints also lead to smaller uncertainty estimates, which imply posterior distributions that do not include the true underlying model in regions where the method has limited sensitivity. This situation can be improved by combining planewave EM methods with complimentary geophysical methods such as ERT. In addition, I show that an appropriate regularization weight and the standard deviation of the data errors can be retrieved by the MCMC inversion. Finally, I evaluate the possibility of characterizing the three-dimensional distribution of an injected water plume by performing three-dimensional time-lapse MCMC inversion of planewave EM data. Since MCMC inversion involves a significant computational burden in high parameter dimensions, I propose a model reduction strategy where the coefficients of a Legendre moment decomposition of the injected water plume and its location are estimated. For this purpose, a base resistivity model is needed which is obtained prior to the time-lapse experiment. A synthetic test shows that the methodology works well when the base resistivity model is correctly characterized. The methodology is also applied to an injection experiment performed in a geothermal system in Australia, and compared to a three-dimensional time-lapse inversion performed within a deterministic framework. The MCMC inversion better constrains the water plumes due to the larger amount of prior information that is included in the algorithm. The conductivity changes needed to explain the time-lapse data are much larger than what is physically possible based on present day understandings. This issue may be related to the base resistivity model used, therefore indicating that more efforts should be given to obtain high-quality base models prior to dynamic experiments. The studies described herein give clear evidence that plane-wave EM methods are useful to characterize and monitor the subsurface at a wide range of scales. The presented approaches contribute to an improved appraisal of the obtained models, both in terms of the incorporation of prior information in the algorithms and the posterior uncertainty quantification. In addition, the developed strategies can be applied to other geophysical methods, and offer great flexibility to incorporate additional information when available.