Spatial distribution of psychotic disorders in an urban area of France: an ecological study

Previous analyses of neighbourhood variations of non-affective psychotic disorders (NAPD) have focused mainly on incidence. However, prevalence studies provide important insights on factors associated with disease evolution as well as for healthcare resource allocation. This study aimed to investigate the distribution of prevalent NAPD cases in an urban area in France. The number of cases in each neighbourhood was modelled as a function of potential confounders and ecological variables, namely: migrant density, economic deprivation and social fragmentation. This was modelled using statistical models of increasing complexity: frequentist models (using Poisson and negative binomial regressions), and several Bayesian models. For each model, assumptions validity were checked and compared as to how this fitted to the data, in order to test for possible spatial variation in prevalence. Data showed significant overdispersion (invalidating the Poisson regression model) and residual autocorrelation (suggesting the need to use Bayesian models). The best Bayesian model was Leroux's model (i.e. a model with both strong correlation between neighbouring areas and weaker correlation between areas further apart), with economic deprivation as an explanatory variable (OR = 1.13, 95% CI [1.02-1.25]). In comparison with frequentist methods, the Bayesian model showed a better fit. The number of cases showed non-random spatial distribution and was linked to economic deprivation

A study of the static yield stress in a binary Lennard-Jones glass

The stress-strain relations and the yield behavior of model glass (a 80:20 binary Lennard-Jones mixture) is studied by means of MD simulations. First, a thorough analysis of the static yield stress is presented via simulations under imposed stress. Furthermore, using steady shear simulations, the effect of physical aging, shear rate and temperature on the stress-strain relation is investigated. In particular, we find that the stress at the yield point (the ``peak''-value of the stress-strain curve) exhibits a logarithmic dependence both on the imposed shear rate and on the ``age'' of the system in qualitative agreement with experiments on amorphous polymers and on metallic glasses. In addition to the very observation of the yield stress which is an important feature seen in experiments on complex systems like pastes, dense colloidal suspensions and foams, further links between our model and soft glassy materials are found. An example are hysteresis loops in the system response to a varying imposed stress. Finally, we measure the static yield stress for our model and study its dependence on temperature. We find that for temperatures far below the mode coupling critical temperature of the model ($Tc = 0.435$), \sigmay decreases slowly upon heating followed by a stronger decrease as \Tc is approached. We discuss the reliability of results on the static yield stress and give a criterion for its validity in terms of the time scales relevant to the problem.Comment: 14 pages, 18 figure

Anomalous acoustic reflection on a sliding interface or a shear band

We study the reflection of an acoustic plane wave from a steadily sliding planar interface with velocity strengthening friction or a shear band in a confined granular medium. The corresponding acoustic impedance is utterly different from that of the static interface. In particular, the system being open, the energy of an in-plane polarized wave is no longer conserved, the work of the external pulling force being partitioned between frictional dissipation and gain (of either sign) of coherent acoustic energy. Large values of the friction coefficient favor energy gain, while velocity strengthening tends to suppress it. An interface with infinite elastic contrast (one rigid medium) and V-independent (Coulomb) friction exhibits spontaneous acoustic emission, as already shown by M. Nosonovsky and G.G. Adams (Int. J. Ing. Sci., {\bf 39}, 1257 (2001)). But this pathology is cured by any finite elastic contrast, or by a moderately large V-strengthening of friction. We show that (i) positive gain should be observable for rough-on-flat multicontact interfaces (ii) a sliding shear band in a granular medium should give rise to sizeable reflection, which opens a promising possibility for the detection of shear localization.Comment: 13 pages, 10 figure

Shear-banding in a lyotropic lamellar phase, Part 2: Temporal fluctuations

We analyze the temporal fluctuations of the flow field associated to a shear-induced transition in a lyotropic lamellar phase: the layering transition of the onion texture. In the first part of this work [Salmon et al., submitted to Phys. Rev. E], we have evidenced banded flows at the onset of this shear-induced transition which are well accounted for by the classical picture of shear-banding. In the present paper, we focus on the temporal fluctuations of the flow field recorded in the coexistence domain. These striking dynamics are very slow (100--1000s) and cannot be due to external mechanical noise. Using velocimetry coupled to structural measurements, we show that these fluctuations are due to a motion of the interface separating the two differently sheared bands. Such a motion seems to be governed by the fluctuations of $\sigma^\star$, the local stress at the interface between the two bands. Our results thus provide more evidence for the relevance of the classical mechanical approach of shear-banding even if the mechanism leading to the fluctuations of $\sigma^\star$ remains unclear

Prognostic value of clinicopathological parameters in head and neck squamous cell carcinoma: a prospective analysis.

The prognostic weight of histological and biological factors was compared with that of known clinical prognostic factors in a population of 108 consecutive previously untreated patients with head and neck squamous cell carcinoma. Parameters studied were: tumour vascularisation, mitotic index, histological differentiation, nuclear grade, keratinisation, desmoplasia, growth pattern, inflammation, tumour emboli in peripheral vessels, keratins 6, 13, 19 immunohistochemical expression, cytofluorometric ploidy and S-phase. In multivariate analysis (Cox), only age and nodal status had a significant impact on the overall survival, whereas T stage was the only significant factor associated with locoregional failure. The cumulative incidence of metastases was correlated not only with age, T and N stage, but also with histological differentiation. All the other histological and biological factors studied failed to provide further prognostic information. These findings may help to select patients with high metastatic risk

Aging dynamics in a colloidal glass of Laponite

The aging dynamics of colloidal suspensions of Laponite, a synthetic clay, is investigated using dynamic light stattering (DLS) and viscometry after a quench into the glassy phase. DLS allows to follow the diffusion of Laponite particles and reveals that there are two modes of relaxation. The fast mode corresponds to a rapid diffusion of particles within "cages" formed by the neighboring particles. The slow mode corresponds to escape from the cages: its average relaxation time increases exponentially fast with the age of the glass. In addition, the slow mode has a broad distribution of relaxation times, its distribution becoming larger as the system ages. Measuring the concomitant increase of viscosity as the system ages, we can relate the slowing down of the particle dynamics to the viscosity.Comment: 9 pages, 8 Postscript figures, submitted to Phys. Rev.

Yield stress, heterogeneities and activated processes in soft glassy materials

The rheological behavior of soft glassy materials basically results from the interplay between shearing forces and an intrinsic slow dynamics. This competition can be described by a microscopic theory, which can be viewed as a nonequilibrium schematic mode-coupling theory. This statistical mechanics approach to rheology results in a series of detailed theoretical predictions, some of which still awaiting for their experimental verification. We present new, preliminary, results about the description of yield stress, flow heterogeneities and activated processes within this theoretical framework.Comment: Paper presented at "III Workshop on Non Equilibrium Phenomena...", Pisa 22-27 Sep. 200

Small-cell lung cancer in England: trends in survival and chemotherapy using the National Lung Cancer Audit

Background: The purpose of this study was to identify trends in survival and chemotherapy use for individuals with smallcell lung cancer (SCLC) in England using the National Lung Cancer Audit (NLCA). Methods: We used data from the NLCA database to identify people with histologically proven SCLC from 2004–2011. We calculated the median survival by stage and assessed whether patient characteristics changed over time. We also assessed whether the proportion of patients with records of chemotherapy and/or radiotherapy changed over time. Results: 18,513 patients were diagnosed with SCLC in our cohort. The median survival was 6 months for all patients, 1 year for those with limited stage and 4 months for extensive stage. 69% received chemotherapy and this proportion changed very slightly over time (test for trends p = 0.055). Age and performance status of patients remained stable over the study period, but the proportion of patients staged increased (p-value,0.001), mainly because of improved data completeness. There has been an increase in the proportion of patients that had a record of receiving both chemotherapy and radiotherapy each year (from 19% to 40% in limited and from 9% to 21% in extensive stage from 2004 to 2011). Patients who received chemotherapy with radiotherapy had better survival compared with any other treatment (HR 0.24, 95% CI 0.23–0.25). Conclusion: Since 2004, when the NLCA was established, the proportion of patients with SCLC having chemotherapy has remained static. We have found an upward trend in the proportion of patients receiving both chemotherapy and radiotherapy which corresponded to a better survival in this group, but as it only applied for a small proportion of patients, it was not enough to change the overall survival

Sequential versus combination chemotherapy for the treatment of advanced colorectal cancer (FFCD 2000-05): an open-label, randomised, phase 3 trial

BACKGROUND: The optimum use of cytotoxic drugs for advanced colorectal cancer has not been defined. Our aim was to investigate whether combination treatment is better than the sequential administration of the same drugs in patients with advanced colorectal cancer. METHODS: In this open-label, randomised, phase 3 trial, we randomly assigned patients (1:1 ratio) with advanced, measurable, non-resectable colorectal cancer and WHO performance status 0-2 to receive either first-line treatment with bolus (400 mg/m(2)) and infusional (2400 mg/m(2)) fluorouracil plus leucovorin (400 mg/m(2)) (simplified LV5FU2 regimen), second-line LV5FU2 plus oxaliplatin (100 mg/m(2)) (FOLFOX6), and third-line LV5FU2 plus irinotecan (180 mg/m(2)) (FOLFIRI) or first-line FOLFOX6 and second-line FOLFIRI. Chemotherapy was administered every 2 weeks. Randomisation was done centrally using minimisation (minimisation factors were WHO performance status, previous adjuvant chemotherapy, number of disease sites, and centre). The primary endpoint was progression-free survival after two lines of treatment. Analyses were by intention-to-treat. This trial is registered at ClinicalTrials.gov, NCT00126256. FINDINGS: 205 patients were randomly assigned to the sequential group and 205 to the combination group. 161 (79%) patients in the sequential group and 161 (79%) in the combination group died during the study. Median progression-free survival after two lines was 10·5 months (95% CI 9·6-11·5) in the sequential group and 10·3 months (9·0-11·9) in the combination group (hazard ratio 0·95, 95% CI 0·77-1·16; p=0·61). All six deaths caused by toxic effects of treatment occurred in the combination group. During first-line chemotherapy, significantly fewer severe (grade 3-4) haematological adverse events (12 events in 203 patients in sequential group vs 83 events in 203 patients in combination group; p<0·0001) and non-haematological adverse events (26 events vs 186 events; p<0·0001) occurred in the sequential group than in the combination group. INTERPRETATION: Upfront combination chemotherapy is more toxic and is not more effective than the sequential use of the same cytotoxic drugs in patients with advanced, non-resectable colorectal cancer. FUNDING: Sanofi-Aventis France