Prediction of cancer survival for cohorts of patients most recently diagnosed using multi-model inference.

Despite a large choice of models, functional forms and types of effects, the selection of excess hazard models for prediction of population cancer survival is not widespread in the literature. We propose multi-model inference based on excess hazard model(s) selected using Akaike information criteria or Bayesian information criteria for prediction and projection of cancer survival. We evaluate the properties of this approach using empirical data of patients diagnosed with breast, colon or lung cancer in 1990-2011. We artificially censor the data on 31 December 2010 and predict five-year survival for the 2010 and 2011 cohorts. We compare these predictions to the observed five-year cohort estimates of cancer survival and contrast them to predictions from an a priori selected simple model, and from the period approach. We illustrate the approach by replicating it for cohorts of patients for which stage at diagnosis and other important prognosis factors are available. We find that model-averaged predictions and projections of survival have close to minimal differences with the Pohar-Perme estimation of survival in many instances, particularly in subgroups of the population. Advantages of information-criterion based model selection include (i) transparent model-building strategy, (ii) accounting for model selection uncertainty, (iii) no a priori assumption for effects, and (iv) projections for patients outside of the sample

Analysis of anisotropy crossover due to oxygen in Pt/Co/MOx trilayer

Extraordinary Hall effect and X-ray spectroscopy measurements have been performed on a series of Pt/Co/MOx trilayers (M=Al, Mg, Ta...) in order to investigate the role of oxidation in the onset of perpendicular magnetic anisotropy at the Co/MOx interface. It is observed that varying the oxidation time modifies the magnetic properties of the Co layer, inducing a magnetic anisotropy crossover from in-plane to out-of-plane. We focused on the influence of plasma oxidation on Pt/Co/AlOx perpendicular magnetic anisotropy. The interfacial electronic structure is analyzed via X-ray photoelectron spectroscopy measurements. It is shown that the maximum of out-of-plane magnetic anisotropy corresponds to the appearance of a significant density of Co-O bondings at the Co/AlOx interface

Cause-specific or relative survival setting to estimate population-based net survival from cancer? An empirical evaluation using women diagnosed with breast cancer in Geneva between 1981 and 1991 and followed for 20 years after diagnosis.

BACKGROUND: Both cause-specific and relative survival settings can be used to estimate net survival, the survival that would be observed if the only possible underlying cause of death was the disease under study. Both resulting net survival estimators are biased by informative censoring and prone to biases related to the data settings within which each is derived. We took into account informative censoring to derive theoretically unbiased estimators and examine which of the two data settings was the most robust against incorrect assumptions in the data. PATIENTS AND METHODS: We identified 2489 women in the Geneva Cancer Registry, diagnosed with breast cancer between 1981 and 1991, and estimated net survival up to 20-years using both cause-specific and relative survival settings, by tackling the informative censoring with weights. To understand the possible origins of differences between the survival estimates, we performed sensitivity analyses within each setting. We evaluated the impact of misclassification of cause of death and of using inappropriate life tables on survival estimates. RESULTS: Net survival was highest using the cause-specific setting, by 1% at one year and by up to around 11% twenty years after diagnosis. Differences between both sets of net survival estimates were eliminated after recoding between 15% and 20% of the non-specific deaths as breast cancer deaths. By contrast, a dramatic increase in the general population mortality rates was needed to see the survival estimates based on relative survival setting become closer to those derived from cause-specific setting. CONCLUSION: Net survival estimates derived using the cause-specific setting are very sensitive to misclassification of cause of death. Net survival estimates derived using the relative-survival setting were robust to large changes in expected mortality. The relative survival setting is recommended for estimation of long-term net survival among patients with breast cancer

Polarization analysis of terahertz radiation generated by four-wave mixing in air

International audienceWe examine the generation of terahertz by optical rectification of fundamental infrared beam with its first harmonic in ionized air. From polarization measurements we identify an important, yet so far unreported cross term (X(3)xyxy + X(3)xyyx) of the nonlinear susceptibility tensor. Omission of this term leads to an error by a factor 10^6 of the THz intensity obtained with certain polarization configurations

Lagrangian temperature and vertical velocity fluctuations due to gravity waves in the lower stratosphere

International audienceWave-induced Lagrangian fluctuations of temperature and vertical velocity in the lower stratosphere are quantified using measurements from superpressure balloons (SPBs). Observations recorded every minute along SPB flights allow the whole gravity wave spectrum to be described and provide unprecedented information on both the intrinsic frequency spectrum and the probability distribution function of wave fluctuations. The data set has been collected during two campaigns coordinated by the French Space Agency in 2010, involving 19 balloons over Antarctica and 3 in the deep tropics. In both regions, the vertical velocity distributions depart significantly from a Gaussian behavior. Knowledge on such wave fluctuations is essential for modeling microphysical processes along Lagrangian trajectories. We propose a new simple parameterization that reproduces both the non-Gaussian distribution of vertical velocities (or heating/cooling rates) and their observed intrinsic frequency spectrum

Estimation of net survival for cancer patients: Relative survival setting more robust to some assumption violations than cause-specific setting, a sensitivity analysis on empirical data.

Net survival is the survival that would be observed if the only possible underlying cause of death was the disease under study. It can be estimated with either cause-specific or relative survival data settings, if the informative censoring is properly considered. However, net survival estimators are prone to specific biases related to the data setting itself. We examined which data setting was the most robust against violation of key assumptions (erroneous cause of death and inappropriate life tables). We identified 4285 women in the Geneva Cancer Registry, diagnosed with breast, colorectal, lung cancer and melanoma between 1981 and 1991 and estimated net survival up to 20 years using cause-specific and relative survival settings. We used weights to tackle informative censoring in both settings and performed sensitivity analyses to evaluate the impact of misclassification of cause of death in the cause-specific setting or of using inappropriate life tables on net survival estimates in the relative survival setting. For all the four cancers, net survival was highest when using the cause-specific setting and the absolute difference between the two estimators increased with time since diagnosis. The sensitivity analysis showed that (i) the use of different life tables did not compromise net survival estimation in the relative survival setting, whereas (ii) a small level of misclassification for the cause of death led to a large change in the net survival estimate in the cause-specific setting. The relative survival setting was more robust to the above assumptions violations and is therefore recommended for estimation of net survival

Maker fringes in the Terahertz radiation produced by a 2-color laser field in air

International audienceThe terahertz radiation produced by a 2-color femtosecond laser scheme strongly saturates and develops an oscillatory behavior with increasing power of the driving femtosecond laser pulses. This is explained by the formation of a plasma channel due to filamentation. Due to dispersion inside the filament and the Gouy phase shift, the phase difference between the 800 nm and 400 nm pulses varies along this plasma emitter. As a result, the local THz radiations generated along the filament interfere destructively or constructively, which manifests itself in the form of Maker fringes

Effect of an external electric field on the coherent terahertz emission from multiple filaments in air

International audienceWe describe the terahertz emission from multiple filaments in air in the presence of an external electric field. A strong enhancement of the radiated terahertz energy is obtained by the combined effect of terahertz field interference and presence of a static electric field

Chrétiens au Proche-Orient

[video:interview-de-bernard-heyberger-chretiens-au-proche-orient] Comme cela a déjà été souligné, aujourd’hui se multiplient les travaux consacrés aux minorités chrétiennes du Proche-Orient, un dynamisme qui contraste fortement avec ce que l’on pouvait observer il y a une vingtaine d’années (B. Heyberger, 2010b ; F. McCallum, 2010a ; P. Rowe, 2010 ; N. Van Doorn-Harder, 2010 ; L. Robson, 2011). Sur l’histoire longue comme sur l’analyse des situations actuelles, la recherche récente a contribu..

Le financement des étudiants en France et en Angleterre de 1945 à 2011 (le student finance, l'award et le salaire étudiant et leur hégémonie.)

La thèse porte sur les politiques de financement des étudiants en France et en Angleterre et les débats publics qui les entourent depuis l après-guerre. Elle s inscrit dans deux questionnements principaux. Dans une perspective de sociologie des politiques sociales, il s agit tout d abord d opérer une comparaison entre les trois ensembles de propositions et de politiques le student finance, l award et le salaire étudiant qui ont traversé les enseignements supérieurs des deux pays depuis 1945. Il s agit ensuite, à partir du concept d hégémonie et de l utilisation qu en a fait Antonio Gramsci au début du 20ème siècle, de soulever la question des modalités de construction de ces régimes dans les deux pays. Les éléments de réponse apportés à ces questionnements se fondent sur l étude des données statistiques disponibles, des archives des syndicats étudiants, de la littérature gouvernementale et de documents diffusés par différents acteurs institutionnels du secteur. La thèse traite de quatre périodes, deux dans chacun des pays, et retrace les débats, les conflits et les politiques qui s y sont déployés. Elle montre finalement que ces régimes de financement se différencient tout d abord par les mesures qui leur sont associées: les prêts, les frais d inscription et les bourses pour le student finance; le paiement par la collectivité des frais d inscription et de vie courante pour l award; et le salaire et la gratuité pour le salaire étudiant. Elle montre aussi que ces régimes se distinguent les uns des autres par leur représentation des étudiants, leur convention de valorisation du travail et de l enseignement supérieur et leurs structures décisionnelles et financières. Elle montre également que la promotion de ces conventions et représentations dans le débat public et le déploiement de ces institutions au sein du secteur permettent à ces ensembles de se mettre en place et aux acteurs qui les portent de construire leur hégémonie.The thesis deals with student funding policies in France and England and the debates that they raised since the post-war years. It answers two main questions. By using the approach of the social policies sociology, it compares the systems of proposals and policies the student finance, the award and the salaire étudiant which have shaped higher education since 1945 in both countries. By using the concept of hegemony that Antonio Gramsci thought it at the beginning of the 20th century, the thesis shows the decision-making process that lead to these proposals and policies. Our materials are composed of the available statistical data, the student union archives, the governmental reports and the documents diffused by the groups involved in the sector. The thesis deals with four periods two in each country and describe the debates, the conflicts and the policy which took place. It shows that those funding systems are founded on different measures: tuition fees, loans and grants for the student finance; the public funding of maintenance and fees for the award; free higher education and wage for the salaire étudiant. It also shows that they are supported by specific representations of students and the value of their work and specific types of funding and decision-making process. It shows finally that the spreading of these ideas in the public debate and the development of these institutions inside the sector make possible the shaping of their policies and of their hegemony.NANTERRE-PARIS10-Bib. élec. (920509901) / SudocSudocFranceF