17 resultados para first principles
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We investigate nuclear magnetic resonance (NMR) parameters of the rhodopsin chromophore in the dark state of the protein and in the early photointermediate bathorhodopsin via first-principles molecular dynamics simulations and NMR chemical shift calculations in a hybrid quantum/classical (QM/MM) framework. NMR parameters are particularly sensitive to structural properties and to the chemical environment, which allows us to address different questions about the retinal chromophore in situ. Our calculations show that both the 13C and the 1H NMR chemical shifts are rather insensitive to the protonation state of Glu181, an ionizable amino acid side chain located in the vicinity of the isomerizing 11-cis bond. Thus, other techniques should be better suited to establish its protonation state. The calculated chemical shifts for bathorhodopsin further support our previously published theoretical structure, which is in very good agreement with more recent X-ray data.
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In this paper the rift between Jevons and Mill over the method of political economy serves as a prehistory to recent attempts of behavioural economists to once again explain economic behaviour by taking recourse to mankind's physiology. While Mill relied on the association psychology and its introspective method to establish indubitable first principles, Jevons scorned all recourse to introspection. As exemplified for Jevons's theory of labour, psychophysiology gave Jevons the means to think about economic behaviour in terms of functional form, and promised its assessment by means of experiments. Thus levelling down the Victorian distinction between mind and matter, Jevons turned political economy into social physics.
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Even though architecture principles were first discussed in the 1990s, they are still perceived as an underexplored topic in enterprise architecture management research. By now, there is an increasing consensus about EA principles' nature, as well as guidelines for their formulation. However, the extant literature remains vague about what can be considered suitable EA design and evolution guidance principles. In addition, empirical insights regarding their role and usefulness in practice are still lacking. Accordingly, this research seeks to address three questions: (1) What are suitable principles to guide EA design and evolution? (2) What usage do EA principles have for practitioners? (3) Which propositions can be derived regarding EA principles' role and application? Opting for exploratory research, we apply a research process covering critical analysis of current publications as well as capturing experts' perceptions. Our research ontologically distinguishes between principles from nonprinciples, proposes a validated set of meta-principles, and clarifies principles' application, role, and usefulness in practice. The explored insights can be used as guidelines in defining suitable principles and turning them into an effective bridge between strategy and design and a guide in design decisions.
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Enterprise-wide architecture has become a necessity for organizations to (re)align information technology (IT) to changing business requirements. Since a city planning metaphor inspired enterprise-wide architecture, this dissertation's research axes can be outlined by similarities between cities and enterprises. Both are characterized as dynamic super-systems that need to address the evolving interest of various architecture stakeholders. Further, both should simultaneously adhere to a set of principles to guide the evolution of architecture towards the expected benefits. The extant literature on enterprise-wide architecture not only disregards architecture adoption's complexities but also remains vague about how principles guide architecture evolution. To bridge this gap, this dissertation contains three interrelated research streams examining the principles and adoption of enterprise-wide architecture. The first research stream investigates organizational intricacies inherent in architecture adoption. It characterizes architecture adoption as an ongoing organizational adaptation process. By analyzing organizational response behaviors in this adaptation process, it also identifies four archetypes that represent very diverse architecture approaches. The second research stream ontologically clarifies the nature of architecture principles along with outlining new avenues for theoretical contributions. This research stream also provides an empirically validated set of principles and proposes a research model illustrating how principles can be applied to generate expected architecture benefits. The third research stream examines architecture adoption in multinational corporations (MNCs). MNCs are Specified by unique organizational characteristics that constantly strive for balancing global integration and local responsiveness. This research stream characterizes MNCs' architecture adoption as a continuous endeavor. This endeavor tries to constantly synchron ize architecture with stakeholders' beliefs about how to balance global integration and local responsiveness. To conclude, this dissertation provides a thorough explanation of a long-term journey in Which organizations learn over time to adopt an effective architecture approach. It also clarifies the role of principles to purposefully guide the aforementioned learning process. - L'Architecture d'Entreprise (AE) est devenue une nécessité pour permettre aux organisations de (ré)aligner les technologies de l'information (TI) avec les changements en termes de besoins métiers. En se basant sur la métaphore de la planification urbaine dont l'AE s'est inspirée, cette dissertation peut être présentée comme une comparaison entre les villes et les entreprises; les deux sont des super-systèmes dynamiques ayant besoin de répondre aux intérêts d'acteurs divers et variés en constants évolution. De plus, les deux devraient souscrire simultanément à un ensemble de principes afin de faire converger l'évolution de l'architecture vers les bénéfices attendus. La littérature sur l'AE, non seulement ne prend pas en considération les complexités de l'adoption d'architecture, mais aussi reste vague sur la manière dont les principes guident l'évolution de l'architecture. Pour pallier ce manque, cette dissertation est composée de trois volets de recherche étroitement liés examinant les principes et l'adoption de l'AE. Le premier volet examine la complexité organisationnelle inhérente à l'adoption de l'architecture. Il caractérise l'adoption de l'architecture en tant que processus d'adaptation continu. En analysant le comportement organisationnel en réponse à ce processus d'adaptation, ce volet distingue quatre archétypes représentant la diversité des approches de l'architecture. Le deuxième volet de recherche clarifie de manière ontologique la nature des principes d'architecture et envisage les contributions théoriques futures possibles. Cet axe de recherche fournit aussi un ensemble de principes, validés de manière empirique, et propose un modèle de recherche illustrant la manière dont ces principes peuvent être appliqués afin de générer les bénéfices attendus de l'architecture. Le troisième volet examine l'adoption de l'architecture dans les entreprises multinationales. Ces dernières possèdent des caractéristiques organisationnelles uniques et sont constamment à la recherche d'un équilibre entre une intégration globale et une flexibilité locale tout en prenant en compte les convictions des divers acteurs sur la manière d'atteindre cet équilibre. Pour conclure, cette dissertation fournit une explication sur le long voyage au cours duquel les entreprises apprennent à adopter une approche d'architecture efficace. Elle clarifie aussi le rôle des principes dans l'accompagnement de ce processus d'apprentissage.
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ABSTRACT This thesis is composed of two main parts. The first addressed the question of whether the auditory and somatosensory systems, like their visual counterpart, comprise parallel functional pathways for processing identity and spatial attributes (so-called `what' and `where' pathways, respectively). The second part examined the independence of control processes mediating task switching across 'what' and `where' pathways in the auditory and visual modalities. Concerning the first part, electrical neuroimaging of event-related potentials identified the spatio-temporal mechanisms subserving auditory (see Appendix, Study n°1) and vibrotactile (see Appendix, Study n°2) processing during two types of blocks of trials. `What' blocks varied stimuli in their frequency independently of their location.. `Where' blocks varied the same stimuli in their location independently of their frequency. Concerning the second part (see Appendix, Study n°3), a psychophysical task-switching paradigm was used to investigate the hypothesis that the efficacy of control processes depends on the extent of overlap between the neural circuitry mediating the different tasks at hand, such that more effective task preparation (and by extension smaller switch costs) is achieved when the anatomical/functional overlap of this circuitry is small. Performance costs associated with switching tasks and/or switching sensory modalities were measured. Tasks required the analysis of either the identity or spatial location of environmental objects (`what' and `where' tasks, respectively) that were presented either visually or acoustically on any given trial. Pretrial cues informed participants of the upcoming task, but not of the sensory modality. - In the audio-visual domain, the results showed that switch costs between tasks were significantly smaller when the sensory modality of the task switched versus when it repeated. In addition, switch costs between the senses were correlated only when the sensory modality of the task repeated across trials and not when it switched. The collective evidence not only supports the independence of control processes mediating task switching and modality switching, but also the hypothesis that switch costs reflect competitive interterence between neural circuits that in turn can be diminished when these neural circuits are distinct. - In the auditory and somatosensory domains, the findings show that a segregation of location vs. recognition information is observed across sensory systems and that these happen around 100ms for both sensory modalities. - Also, our results show that functionally specialized pathways for audition and somatosensation involve largely overlapping brain regions, i.e. posterior superior and middle temporal cortices and inferior parietal areas. Both these properties (synchrony of differential processing and overlapping brain regions) probably optimize the relationships across sensory modalities. - Therefore, these results may be indicative of a computationally advantageous organization for processing spatial anal identity information.
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Bacterial reporters are live, genetically engineered cells with promising application in bioanalytics. They contain genetic circuitry to produce a cellular sensing element, which detects the target compound and relays the detection to specific synthesis of so-called reporter proteins (the presence or activity of which is easy to quantify). Bioassays with bacterial reporters are a useful complement to chemical analytics because they measure biological responses rather than total chemical concentrations. Simple bacterial reporter assays may also replace more costly chemical methods as a first line sample analysis technique. Recent promising developments integrate bacterial reporter cells with microsystems to produce bacterial biosensors. This lecture presents an in-depth treatment of the synthetic biological design principles of bacterial reporters, the engineering of which started as simple recombinant DNA puzzles, but has now become a more rational approach of choosing and combining sensing, controlling and reporting DNA 'parts'. Several examples of existing bacterial reporter designs and their genetic circuitry will be illustrated. Besides the design principles, the lecture also focuses on the application principles of bacterial reporter assays. A variety of assay formats will be illustrated, and principles of quantification will be dealt with. In addition to this discussion, substantial reference material is supplied in various Annexes.
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France amended its constitution in 2005 to include a Charter for the Environment. The Charter lays out France's commitment to supporting the right to a 'balanced environment'. This article first traces the Charter's origins to a legacy-building presidential initiative. Jacques Chirac decided to invest in a neglected policy domain in which his own majority had shown little interest. He was obliged to intervene repeatedly in order to bring this project to a successful conclusion. In doing so, he staked out environmental affairs as an area of potential presidential supremacy. Next, the content of the Charter is examined. In this document, French traditions of universalism come together with an international movement for anticipatory environmental protection. This is reflected in the constitutionalisation of the precautionary principle, which emerged as the most controversial part of the Charter. The debates this provoked tended to caricature a risk-management principle whose meaning has been carefully refined to forestall objections. Finally, the Charter's potential efficacy is analysed. The post-Charter record of legislative and judicial activity concerning the environment is meagre, but not wholly inauspicious.
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The progress in prenatal medicine raises complex questions with respect to the physician-patient relationship. The physician needs to reconcile medical aspects, ethical principles as well as judicial norms. Already, during the first trimester, the physician has to put into practice the schedule combining for each individual pregnancy physical, laboratory and other appropriate exams. Physicians are under the obligation to inform in a clear and comprehensive way without creating unnecessary anxiety for their patients. Legal requirements include informed consent, the respect for the patient's right to self-determination, and compliance with the Swiss federal law on genetic testing, especially with its articles on prenatal screening and diagnosis. This article discusses the complexity of obstetrical practice when it comes to delivering adequate information within the scope of ethical and legal requirements in Switzerland. L'évolution de la médecine prénatale soulève des enjeux complexes dans la relation médecin-patient. Il s'agit de concilier à la fois les aspects médicaux, les principes éthiques et les normes juridiques. Dès le premier trimestre de la grossesse le médecin doit poser le cadre du suivi et des examens appropriés pour chaque grossesse. Son devoir est d'informer de manière claire et précise sans inquiéter inutilement, en respectant l'exigence légale d'un consentement éclairé et plus largement le droit de la patiente à l'autodétermination ainsi que le cadre de la loi fédérale suisse sur l'analyse génétique humaine dans le domaine du dépistage et du diagnostic prénatal. Cet article discute de la complexité de l'information et de l'application des principes éthiques et légaux dans la pratique obstétricale en Suisse.
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BACKGROUND: Treatment strategies for mental disorders may vary according to illness stage. However no data currently exist to guide treatment in first episode psychotic mania. The aim of this study was to compare the safety and efficacy profile of chlorpromazine and olanzapine, as add-on to lithium, in patients with a first episode of psychotic mania, expecting better safety profile and adherence to olanzapine but similar efficacy for both treatments. METHODS: Data from 83 patients were collected in an 8-week randomised controlled trial on clinical variables, side effects, vital signs, and weight. Analyses of treatment differences over time were based on intent-to-treat principles. Kaplan-Meier estimated survival curves were used to analyse time-to-event data and mixed effects models repeated measures analysis of variance were used to determine treatment group differences over time on safety and efficacy measures. RESULTS: Ethics committee approval to delay informed consent procedure until recovery from the acute episode allowed the inclusion of 83 patients highly representative of those treated in the public sector. Contrary to our hypotheses, safety profile of both medications was similar. A signal for higher rate (P=.032) and earlier occurrence (P=.043) of mania remission was observed in the olanzapine group which did not survive correction for multiple comparisons. CONCLUSIONS: Olanzapine and chlorpromazine have a similar safety profile in a uniquely representative cohort of patients with first episode psychotic mania. The possibility for a greater impact of olanzapine on manic symptoms leading to earlier remission of the episode needs exploration in a large sample.
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In recent years, technological advances have allowed manufacturers to implement dual-energy computed tomography (DECT) on clinical scanners. With its unique ability to differentiate basis materials by their atomic number, DECT has opened new perspectives in imaging. DECT has been used successfully in musculoskeletal imaging with applications ranging from detection, characterization, and quantification of crystal and iron deposits; to simulation of noncalcium (improving the visualization of bone marrow lesions) or noniodine images. Furthermore, the data acquired with DECT can be postprocessed to generate monoenergetic images of varying kiloelectron volts, providing new methods for image contrast optimization as well as metal artifact reduction. The first part of this article reviews the basic principles and technical aspects of DECT including radiation dose considerations. The second part focuses on applications of DECT to musculoskeletal imaging including gout and other crystal-induced arthropathies, virtual noncalcium images for the study of bone marrow lesions, the study of collagenous structures, applications in computed tomography arthrography, as well as the detection of hemosiderin and metal particles.
Resumo:
In recent years, technological advances have allowed manufacturers to implement dual-energy computed tomography (DECT) on clinical scanners. With its unique ability to differentiate basis materials by their atomic number, DECT has opened new perspectives in imaging. DECT has been successfully used in musculoskeletal imaging with applications ranging from detection, characterization, and quantification of crystal and iron deposits, to simulation of noncalcium (improving the visualization of bone marrow lesions) or noniodine images. Furthermore, the data acquired with DECT can be postprocessed to generate monoenergetic images of varying kiloelectron volts, providing new methods for image contrast optimization as well as metal artifact reduction. The first part of this article reviews the basic principles and technical aspects of DECT including radiation dose considerations. The second part focuses on applications of DECT to musculoskeletal imaging including gout and other crystal-induced arthropathies, virtual noncalcium images for the study of bone marrow lesions, the study of collagenous structures, applications in computed tomography arthrography, as well as the detection of hemosiderin and metal particles.
Resumo:
BACKGROUND: First hospitalisation for a psychotic episode causes intense distress to patients and families, but offers an opportunity to make a diagnosis and start treatment. However, linkage to outpatient psychiatric care remains a notoriously difficult step for young psychotic patients, who frequently interrupt treatment after hospitalisation. Persistence of symptoms, and untreated psychosis may therefore remain a problem despite hospitalisation and proper diagnosis. With persisting psychotic symptoms, numerous complications may arise: breakdown in relationships, loss of family and social support, loss of employment or study interruption, denial of disease, depression, suicide, substance abuse and violence. Understanding mechanisms that might promote linkage to outpatient psychiatric care is therefore a critical issue, especially in early intervention in psychotic disorders. OBJECTIVE: To study which factors hinder or promote linkage of young psychotic patients to outpatient psychiatric care after a first hospitalisation, in the absence of a vertically integrated program for early psychosis. Method. File audit study of all patients aged 18 to 30 who were admitted for the first time to the psychiatric University Hospital of Lausanne in the year 2000. For statistical analysis, chi2 tests were used for categorical variables and t-test for dimensional variables; p<0.05 was considered as statistically significant. RESULTS: 230 patients aged 18 to 30 were admitted to the Lausanne University psychiatric hospital for the first time during the year 2000, 52 of them with a diagnosis of psychosis (23%). Patients with psychosis were mostly male (83%) when compared with non-psychosis patients (49%). Furthermore, they had (1) 10 days longer mean duration of stay (24 vs 14 days), (2) a higher rate of compulsory admissions (53% vs 22%) and (3) were more often hospitalised by a psychiatrist rather than by a general practitioner (83% vs 53%). Other socio-demographic and clinical features at admission were similar in the two groups. Among the 52 psychotic patients, 10 did not stay in the catchment area for subsequent treatment. Among the 42 psychotic patients who remained in the catchment area after discharge, 20 (48%) did not attend the scheduled or rescheduled outpatient appointment. None of the socio demographic characteristics were associated with attendance to outpatient appointments. On the other hand, voluntary admission and suicidal ideation before admission were significantly related to attending the initial appointment. Moreover, some elements of treatment seemed to be associated with higher likelihood to attend outpatient treatment: (1) provision of information to the patient regarding diagnosis, (2) discussion about the treatment plan between in- and outpatient staff, (3) involvement of outpatient team during hospitalisation, and (4) elaboration of concrete strategies to face basic needs, organise daily activities or education and reach for help in case of need. CONCLUSION: As in other studies, half of the patients admitted for a first psychotic episode failed to link to outpatient psychiatric care. Our study suggests that treatment rather than patient's characteristics play a critical role in this phenomenon. Development of a partnership and involvement of patients in the decision process, provision of good information regarding the illness, clear definition of the treatment plan, development of concrete strategies to cope with the illness and its potential complications, and involvement of the outpatient treating team already during hospitalisation, all came out as critical strategies to facilitate adherence to outpatient care. While the current rate of disengagement after admission is highly concerning, our finding are encouraging since they constitute strategies that can easily be implemented. An open approach to psychosis, the development of partnership with patients and a better coordination between inpatient and outpatient teams should therefore be among the targets of early intervention programs. These observations might help setting up priorities when conceptualising new programs and facilitate the implementation of services that facilitate engagement of patients in treatment during the critical initial phase of psychotic disorders.
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INTRODUCTION: We examined the positive and negative subjective feelings associated with initial tobacco and cannabis use as well as the role of these experiences in regular use. Additionally, we investigated the effect of the first substance experienced on initial subjective experiences and later regular use. METHODS: Baseline data from a representative sample of young Swiss men were obtained from an ongoing Cohort Study on Substance Use Risk Factors, which includes 2,321 lifetime tobacco and cannabis users. We assessed the age of first tobacco and cannabis use along with the subjective experiences associated with initial use. Additionally, subjective experiences related to regular use of both substances were analyzed. RESULTS: The initial subjective experiences were divided into positive and negative for each substance, and we found that the feelings associated with first use of tobacco and cannabis were similar. Moreover, the participants who used cannabis before tobacco reported fewer negative experiences associated with first tobacco use, whereas the participants who initially used tobacco reported more negative experiences related to first cannabis use. Also, we identified that regular use was encouraged by positive experiences and that negative experiences were more adverse for regular use of cannabis compared with tobacco. CONCLUSIONS: Taken together, these results indicate that similar subjective experiences were associated with the first use of tobacco and cannabis. Also, the use of cannabis before tobacco, which occurred in only a minority of users, had the potential to enhance the effects of initial tobacco use.
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Background a nd Aims: T he international E EsAI study g roupis currently developing the first activity index (EEsAI) specificfor Eosinophilic Esophagitis (EoE). Goal: To develop, evaluateand validate the EEsAI.Methods: T he d evelopment comprises three phases: 1.Selection of candidate items; 2. Evaluation of the activity indexin a f irst patient cohort; and 3. V alidation in a s econd EoEpatient cohort. Focus group interviews with patients were usedin p hase 1 to generate p atient r eported outcomes ( PRO)according to guidelines o f regulatory authorities ( FDA andEMA), whereas the section of biologic items was developed byDelphi r ounds of i nternational E oE experts from E urope andNorth America.Results: The EEsAI has a modular composition to assess thefollowing components o f EoE activity: p atient reportedoutcomes, endoscopic activity, histologic activity, laboratoryactivity, a nd quality of life. D efinitions f or all aspects o fendoscopic and histologic appearance were established byconsensus rounds among EoE experts. Symptom assessmenttools were created that take into account d ifferent foodconsistencies as w ell as f ood avoidance and specificprocessing strategies. T he EEsAI is evaluated in a c ohort ofadult EoE patients since March 2011.Conclusions: After successful validation, the EEsAI will allowto standardize outcome assessment in E oE t rials which w illlikely lead to its wide applicability.
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The FIT trial was conducted to evaluate the safety and efficacy of 90Y-ibritumomab tiuxetan (0.4 mCi/kg; maximum dose 32 mCi) when used as consolidation of first complete or partial remission in patients with previously untreated, advanced-stage follicular lymphoma (FL). Patients were randomly assigned to either 90Y-ibritumomab treatment (n = 207) or observation (n = 202) within 3 months (mo) of completing initial induction therapy (chemotherapy only: 86%; rituximab in combination with chemotherapy: 14%). Response status prior to randomization did not differ between the groups: 52% complete response (CR)/CR unconfirmed (CRu) to induction therapy and 48% partial response (PR) in the 90Y-ibritumomab arm vs 53% CR/CRu and 44% PR in the control arm. The primary endpoint was progression-free survival (PFS) of the intent-to-treat (ITT) population. Results from the first extended follow-up after a median of 3.5 years revealed a significant improvement in PFS from the time of randomization with 90Y-ibritumomab consolidation compared with control (36.5 vs 13.3 mo, respectively; P < 0.0001; Morschhauser et al. JCO. 2008; 26:5156-5164). Here we report a median follow-up of 66.2 mo (5.5 years). Five-year PFS was 47% in the 90Y-ibritumomab group and 29% in the control group (hazard ratio (HR) = 0.51, 95% CI 0.39-0.65; P < 0.0001). Median PFS in the 90Y-ibritumomab group was 49 mo vs 14 mo in the control group. In patients achieving a CR/CRu after induction, 5-year PFS was 57% in the 90Y-ibritumomab group, and the median had not yet been reached at 92 months, compared with a 43% 5-year PFS in the control group and a median of 31 mo (HR = 0.61, 95% CI 0.42-0.89). For patients in PR after induction, the 5-year PFS was 38% in the 90Y-ibritumomab group with a median PFS of 30 mo vs 14% in the control group with a median PFS of 6 mo (HR = 0.38, 95% CI 0.27-0.53). Patients who had received rituximab as part of induction treatment had a 5-year PFS of 64% in the 90Y-ibritumomab group and 48% in the control group (HR = 0.66, 95% CI 0.30-1.47). For all patients, time to next treatment (as calculated from the date of randomization) differed significantly between both groups; median not reached at 99 mo in the 90Y-ibritumomab group vs 35 mo in the control group (P < 0.0001). The majority of patients received rituximab-containing regimens when treated after progression (63/82 [77%] in the 90Y-ibritumomab group and 102/122 [84%] in the control group). Overall response rate to second-line treatment was 79% in the 90Y-ibritumomab group (57% CR/CRu and 22% PR) vs 78% in the control arm (59% CR/CRu, 19% PR). Five-year overall survival was not significantly different between the groups; 93% and 89% in the 90Y-ibritumomab and control groups, respectively (P = 0.561). To date, 40 patients have died; 18 in the 90Y-ibritumomab group and 22 in the control group. Secondary malignancies were diagnosed in 16 patients in the 90Y-ibritumomab arm vs 9 patients in the control arm (P = 0.19). There were 6 (3%) cases of myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML) in the 90Y-ibritumomab arm vs 1 MDS in the control arm (P = 0.063). In conclusion, this extended follow-up of the FIT trial confirms the benefit of 90Y-ibritumomab consolidation with a nearly 3 year advantage in median PFS. A significant 5-year PFS improvement was confirmed for patients with a CR/CRu or a PR after induction. Effective rescue treatment with rituximab-containing regimens may explain the observed no difference in overall survival between both patient groups who were - for the greater part - rituximab-naïve.