Almost reducibility for finitely differentiable SL(2,R)-valued quasi-periodic cocycles

Quasi-periodic cocycles with a diophantine frequency and with values in SL(2,R) are shown to be almost reducible as long as they are close enough to a constant, in the topology of k times differentiable functions, with k great enough. Almost reducibility is obtained by analytic approximation after a loss of differentiability which only depends on the frequency and on the constant part. As in the analytic case, if their fibered rotation number is diophantine or rational with respect to the frequency, such cocycles are in fact reducible. This extends Eliasson's theorem on Schr\"odinger cocycles to the differentiable case

Network Mutual Information and Synchronization under Time Transformations

We investigate the effect of general time transformations on the phase synchronization (PS) phenomenon and the mutual information rate (MIR) between pairs of nodes in dynamical networks. We demonstrate two important results concerning the invariance of both PS and the MIR. Under time transformations PS can neither be introduced nor destroyed and the MIR cannot be raised from zero. On the other hand, for proper time transformations the timing between the cycles of the coupled oscillators can be largely improved. Finally, we discuss the relevance of our findings for communication in dynamical networks.Comment: 15 p

Infinite ergodic theory and Non-extensive entropies

We bring into account a series of result in the infinite ergodic theory that we believe that they are relevant to the theory of non-extensive entropie

Regional scale rain-forest height mapping using regression-kriging of spaceborne and airborne lidar data : application on French Guiana

LiDAR data has been successfully used to estimate forest parameters such as canopy heights and biomass. Major limitation of LiDAR systems (airborne and spaceborne) arises from their limited spatial coverage. In this study, we present a technique for canopy height mapping using airborne and spaceborne LiDAR data (from the Geoscience Laser Altimeter System (GLAS)). First, canopy heights extracted from both airborne and spaceborne LiDAR were extrapolated from available environmental data. The estimated canopy height maps using Random Forest (RF) regression from airborne or GLAS calibration datasets showed similar precisions (~6 m). To improve the precision of canopy height estimates, regression-kriging was used. Results indicated an improvement in terms of root mean square error (RMSE, from 6.5 to 4.2 m) using the GLAS dataset, and from 5.8 to 1.8 m using the airborne LiDAR dataset. Finally, in order to investigate the impact of the spatial sampling of future LiDAR missions on canopy height estimates precision, six subsets were derived from the initial airborne LiDAR dataset. Results indicated that using the regression-kriging approach a precision of 1.8 m on the canopy height map was achievable with a flight line spacing of 5 km. This precision decreased to 4.8 m for flight line spacing of 50 km

Mass Production and Size Control of Lipid–Polymer Hybrid Nanoparticles through Controlled Microvortices

Lipid–polymer hybrid (LPH) nanoparticles can deliver a wide range of therapeutic compounds in a controlled manner. LPH nanoparticle syntheses using microfluidics improve the mixing process but are restricted by a low throughput. In this study, we present a pattern-tunable microvortex platform that allows mass production and size control of LPH nanoparticles with superior reproducibility and homogeneity. We demonstrate that by varying flow rates (i.e., Reynolds number (30–150)) we can control the nanoparticle size (30–170 nm) with high productivity (~3 g/hour) and low polydispersity (~0.1). Our approach may contribute to efficient development and optimization of a wide range of multicomponent nanoparticles for medical imaging and drug delivery.National Heart, Lung, and Blood Institute (Program of Excellence in Nanotechnology (PEN) Award Contract HHSN268201000045C)National Cancer Institute (U.S.) (Grant P01 CA151884)Prostate Cancer Foundation (Award in Nanotherapeutics

Cap inflammation leads to higher plaque cap strain and lower cap stress: An MRI-PET/CT-based FSI modeling approach.

Plaque rupture may be triggered by extreme stress/strain conditions. Inflammation is also implicated and can be imaged using novel imaging techniques. The impact of cap inflammation on plaque stress/strain and flow shear stress were investigated. A patient-specific MRI-PET/CT-based modeling approach was used to develop 3D fluid-structure interaction models and investigate the impact of inflammation on plaque stress/strain conditions for better plaque assessment. 18FDG-PET/CT and MRI data were acquired from 4 male patients (average age: 66) to assess plaque characteristics and inflammation. Material stiffness for the fibrous cap was adjusted lower to reflect cap weakening causing by inflammation. Setting stiffness ratio (SR) to be 1.0 (fibrous tissue) for baseline, results for SR=0.5, 0.25, and 0.1 were obtained. Thin cap and hypertension were also considered. Combining results from the 4 patients, mean cap stress from 729 cap nodes was lowered by 25.2% as SR went from 1.0 to 0.1. Mean cap strain value for SR=0.1 was 0.313, 114% higher than that from SR=1.0 model. The thin cap SR=0.1 model had 40% mean cap stress decrease and 81% cap strain increase compared with SR=1.0 model. The hypertension SR=0.1 model had 19.5% cap stress decrease and 98.6% cap strain increase compared with SR=1.0 model. Differences of flow shear stress with 4 different SR values were limited (<10%). Cap inflammation may lead to large cap strain conditions when combined with thin cap and hypertension. Inflammation also led to lower cap stress. This shows the influence of inflammation on stress/strain calculations which are closely related to plaque assessment.This work was supported in part by NIH grants NIH/NIBIB R01 EB004759, NIH/NHLBI R01 HL071021, and National Natural Sciences Foundation of China grant 11672001, 11171030

Association between body-mass index and quality of split bowel preparation

BACKGROUND & AIMS: Little is known about the association between obesity and bowel preparation. We investigated whether body mass index (BMI) is an independent risk factor for inadequate bowel preparation in patients who receive split preparation regimens. METHODS: We performed a retrospective study of data from 2163 consecutive patients (mean age, 60.6 ± 10.5 y; 93.8% male) who received outpatient colonoscopies in 2009 at the Veterans Affairs Medical Center in Indianapolis, Indiana. All patients received a split preparation, categorized as adequate (excellent or good, based on the Aronchick scale) or inadequate. We performed a multivariable analysis to identify factors independently associated with inadequate preparation. RESULTS: Bowel preparation quality was inadequate for 44.2% of patients; these patients had significantly higher mean BMIs than patients with adequate preparation (31.2 ± 6.5 vs 29.8 ± 5.9, respectively; P < .0001) and Charlson comorbidity scores (1.5 ± 1.6 vs 1.1 ± 1.4; P < .0001). Independent risk factors for inadequate preparation were a BMI of 30 kg/m(2) or greater (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.21-1.75; P < .0001), use of tobacco (OR, 1.28; 95% CI, 1.07-1.54; P = .0084) or narcotics (OR, 1.28; 95% CI, 1.04-1.57; P = .0179), hypertension (OR, 1.30; 95% CI, 1.07-1.57; P = .0085), diabetes (OR, 1.38; 95% CI, 1.12-1.69; P = .0021), and dementia (OR, 3.02; 95% CI, 1.22-7.49; P = .0169). CONCLUSIONS: BMI is an independent factor associated with inadequate split bowel preparation for colonoscopy. Additional factors associated with quality of bowel preparation include diabetes, hypertension, dementia, and use of tobacco and narcotics. Patients with BMIs of 30 kg/m(2) or greater should be considered for more intensive preparation regimens