Scattering of entangled two-photon states.

We consider the scattering of entangled two-photon states from collections of small particles. We also study the related Mie problem of scattering from a sphere. In both cases, we calculate the entropy of entanglement and investigate the influence of the entanglement of the incident field on the entanglement of the scattered field.

Diagrammatic and asymptotic approaches to the origins of radiative transport theory: tutorial.

The radiative transport equation (RTE) is used widely to describe the propagation of multiply scattered light in disordered media. In this tutorial, we present two derivations of the RTE for scalar wave fields. The first derivation is based on diagrammatic perturbation theory, while the second stems from an asymptotic multiscale expansion. Although the two approaches are quite distinct mathematically, some common ground can be found and is discussed.

Mapping and quantifying electric and magnetic dipole luminescence at the nanoscale.

We report on an experimental technique to quantify the relative importance of electric and magnetic dipole luminescence from a single nanosource in structured environments. By attaching a Eu^{3+}-doped nanocrystal to a near-field scanning optical microscope tip, we map the branching ratios associated with two electric dipole and one magnetic dipole transitions in three dimensions on a gold stripe. The relative weights of the electric and magnetic radiative local density of states can be recovered quantitatively, based on a multilevel model. This paves the way towards the full electric and magnetic characterization of nanostructures for the control of single emitter luminescence.

Towards a full characterization of a plasmonic nanostructure with a fluorescent near-field probe.

We report on the experimental and theoretical study of the spatial fluctuations of the local density of states (EM-LDOS) and of the fluorescence intensity in the near-field of a gold nanoantenna. EM-LDOS, fluorescence intensity and topography maps are acquired simultaneously by scanning a fluorescent nanosource grafted on the tip of an atomic force microscope at the surface of the sample. The results are in good quantitative agreement with numerical simulations. This work paves the way for a full near-field characterization of an optical nanoantenna.

Spatial coherence in complex photonic and plasmonic systems.

The concept of cross density of states characterizes the intrinsic spatial coherence of complex photonic or plasmonic systems, independently of the illumination conditions. Using this tool and the associated intrinsic coherence length, we demonstrate unambiguously the spatial squeezing of eigenmodes on disordered fractal metallic films, thus clarifying a basic issue in plasmonics.

Strong coupling to two-dimensional Anderson localized modes.

We use a scattering formalism to derive a condition of strong coupling between a resonant scatterer and an Anderson localized mode for electromagnetic waves in two dimensions. The strong coupling regime is demonstrated based on exact numerical simulations, in perfect agreement with theory. The strong coupling threshold can be expressed in terms of the Thouless conductance and the Purcell factor. This connects key concepts in transport theory and cavity quantum electrodynamics, and provides a practical tool for the design or analysis of experiments.

Distance dependence of the local density of states in the near field of a disordered plasmonic film.

We measure the statistical distribution of the photonic local density of states in the near field of a semicontinuous gold film. By varying the distance between the measurement plane and the film, we show that near-field confined modes play a major role in the width of the distribution. Numerical simulations in good agreement with experiments allow us to point out the influence of nonradiative decay channels at short distance.

Estimating risk from underpowered, but statistically significant, studies: was APPROVe on TARGET?

WHAT IS KNOWN AND OBJECTIVE: The importance of statistical power is widely recognized from a pre-trial perspective, and when interpreting results that are not statistically significant. It is less well recognized that poor power can lead to inflated estimates of the effect size when statistically significant results are observed. We use trial simulations to quantify this bias, which we term 'significant-result bias'. COMMENT: Significant-result bias is explained, and simulations are used to estimate possible significant-result bias in the rate of thrombotic events observed in the APPROVe trial. Statistically significant results, on outcomes for which there is empirical evidence of poor power, may provide inflated estimates of the size of effect. WHAT IS NEW AND CONCLUSION: If independent evidence is available to judge the likely effect size of an underpowered statistical test, trial simulations can provide a method for quantifying significant-result bias.

[Parapharyngeal tumors: diagnosis and treatment]. / Tumeurs parapharyngées: diagnostic et traitement.

OBJECTIVES: Parapharyngeal space tumors are rare and usually benign. Their treatment is surgical and many approaches have been described. We report our experience in managing these neoplasms. Two points are developed more fully: the correlation between imaging and surgical observation and the reliability of the cervical approach. MATERIAL AND METHODS: A retrospective review of primary parapharyngeal space tumors treated at the Rennes University Hospital between 1992 and 2004 is presented. Nine patients were included, all treated surgically with a cervical approach without parotidectomy. RESULTS: Eight MR imaging and seven CT scans were done. Two retrostyloid tumors and six prestyloid tumors, all independent of the deep lobe of the parotid gland, were found. They were benign in all cases (five salivary tumors and four schwannomas). Two patients treated for a pleomorphic adenoma presented recurrence and were reoperated successfully. The average follow-up was 66 months. None of the patients died. Definitive postoperative complications occurred only for neurogenic tumors. CONCLUSION: The cervical approach is safe and allows the surgical excision of retrostyloid and prestyloid tumors, independent of the deep lobe of the parotid gland. Large tumor (8cm in our study) excision can be done with few complications. An attentive study of preoperative imaging is necessary to choose the best surgical approach.

[Neck dissection for stage N0 oral cavity carcinoma]. / Evidement cervical dans les carcinomes de la cavité orale classes N0.

OBJECTIVES: The management of N0 neck remains controversial. The purpose of this study was to evaluate the efficacy of selective neck dissection (SND) in managing N0 neck of oral cavity carcinomas. MATERIAL AND METHODS: A retrospective chart review of 77 previously untreated patients with squamous cell carcinomas of the oral cavity with N0 neck from 1988 to 2001 was performed. Cervical treatments were "wait and see" policy in 7 cases, neck dissection in 56 cases, radiotherapy alone in 14 cases. 77 neck dissections were performed in which 62 were selective and 15 were radical modified. RESULTS: On pathologic examination, the average number of lymph nodes was 10.7 per neck. Occult disease (cN0pN+) was detected in 32.5%, and occult extracapsular spread (cN0pN+R+) was detected in 7.8%. The median follow-up was 43 months. The overall neck recurrence rate in patients with controlled primary disease was 2.4%. Recurrent disease developed in 2.9% of the cNOpN0 neck. Regional control rate of the dissected neck was 94%. No cervical recurrence occurred in 11 patients treated with SND alone. There was no survival or recurrence rate difference in T1T2pN0 patients with or without post-operative radiotherapy. Post-operative radiotherapy could be avoided in 27% of the dissected neck. One, 3 and 5 years overall survival rate were 89.3%, 77.7% and 63.2%. CONCLUSIONS: SND is an effective procedure for staging and treating the clinically negative neck of oral cavity cancer.