Continuous affect recognition with weakly supervised learning

Multimedia Tools and Applications - Recognizing a person’s affective state from audio-visual signals is an essential capability for intelligent interaction. Insufficient training data and the...     

Controlling the Dimensions of Carbon Nanofiber Structures through the Electropolymerization of Pyrrole

Electrically conductive polymers, such as polypyrrole (PPy), show promise for modifying the dimensions and properties of micro- and nanoscale structures. Mechanisms for controlling the formation of PPy films of nanoscale thickness were evaluated by electrochemically synthesizing and examining PPy films on planar gold electrodes under a variety of growth conditions. Tunable PPy coatings were then deposited by electropolymerization on the sidewalls of individual, electrically addressable carbon nanofibers (CNFs). The ability to modify the physical size of specific nanofibers in controllable fashion is demonstrated. The biocompatibility, potential for chemical functionalization, and ability to effect volume changes of this nanocomposite can lead to advanced functionality, such as specific, nanoscale valving of materials and morphological control at the nanoscale.     

A model for the induction of chromosome aberrations through direct and bystander mechanisms

A state vector model (SVM) for chromosome aberrations and neoplastic transformation has been adapted to describe detrimental bystander effects. The model describes initiation (formation of translocations) and promotion (clonal expansion and loss of contact inhibition of initiated cells). Additional terms either in the initiation model or in the rate of clonal expansion of initiated cells, describe detrimental bystander effects for chromosome aberrations as reported in the scientific literature. In the present study, the SVM with bystander effects is tested on a suitable dataset. In addition to the simulation of non-linear effects, a classical dataset for neoplastic transformation in C3H 10T1/2 cells after alpha particle irradiation is used to show that the model without bystander features can also describe LNT-like dose responses. A published model for bystander induced neoplastic transformation was adapted for chromosome aberration induction and used to compare the results obtained with the different models.     

Growth of Graphene-Like Structures on an Oxidized SiC Surface

Graphene-like structures were formed on an oxidized SiC (0001) surface following thermal annealing in a vacuum at high temperatures. The SiO₂/SiC structure was annealed at 1350°C in 10⁻⁵ Torr; the SiO₂ layer was vaporized, and two layer graphene-like structures were formed on the SiC surface. This method of fabricating graphene did not require an ultra-high vacuum. In the absence of the oxide layer, a film of vertical carbon nanotubes (CNTs) was grown on the SiC surface in the same temperature range at 10⁻⁵ Torr.     

Hydrophilic behavior of HSPAN/PVA membrane

The hydrophilic behavior including water absorption, swelling, and dielectric spectrum of pure HSPAN as well as HSPAN/PVA blends are investigated. The HSPAN/PVA membranes still absorb a considerable amount of water. The effect of water upon mechanical properties is also investigated for these membranes. Formalization of membrane enhances mechanical properties and reduces weight losses during swelling with much loss in the water absorption ability of PVA. This kind of blend shows promise as material for hydrophilic membranes.     

Primary angioplasty using a urokinase-coated hydrogel balloon in acute myocardial infarction during pregnancy

A 38-year-old multigravid white female presented at 16 weeks gestation with an acute inferoposterolateral myocardial infarction. Emergent coronary angiography demonstrated a total proximal occlusion of a large dominant left circumflex artery with a filling defect at the site of the occlusion suggestive of thrombus. Primary angioplasty using a urokinase-coated hydrogel balloon resulted in successful recanalization of the vessel with restoration of normal TIMI Grade III flow and, most notably, apparent complete lysis of the intracoronary thrombus. After a subsequently uneventful pregnancy, a healthy baby was delivered.     

Assessing model mismatch and model selection in a Bayesian uncertainty quantification analysis of a fluid-dynamics model of pulmonary blood circulation

This study uses Bayesian inference to quantify the uncertainty of model parameters and haemodynamic predictions in a one-dimensional pulmonary circulation model based on an integration of mouse haemodynamic and micro-computed tomography imaging data. We emphasize an often neglected, though important source of uncertainty: in the mathematical model form due to the discrepancy between the model and the reality, and in the measurements due to the wrong noise model (jointly called ‘model mismatch’). We demonstrate that minimizing the mean squared error between the measured and the predicted data (the conventional method) in the presence of model mismatch leads to biased and overly confident parameter estimates and haemodynamic predictions. We show that our proposed method allowing for model mismatch, which we represent with Gaussian processes, corrects the bias. Additionally, we compare a linear and a nonlinear wall model, as well as models with different vessel stiffness relations. We use formal model selection analysis based on the Watanabe Akaike information criterion to select the model that best predicts the pulmonary haemodynamics. Results show that the nonlinear pressure–area relationship with stiffness dependent on the unstressed radius predicts best the data measured in a control mouse.     

Microscale confinement features can affect biofilm formation

The majority of bacteria in nature live in biofilms, where they are encased by extracellular polymeric substances (EPS) and adhere to various surfaces and interfaces. Investigating the process of biofilm formation is critical for advancing our understanding of microbes in their most common mode of living. Despite progress in characterizing the effect of various environmental factors on biofilm formation, work remains to be done in the realm of exploring the inter-relationship between hydrodynamics, microbial adhesion and biofilm growth. We investigate the impact of secondary flow structures, which are created due to semi-confined features in a microfluidic device, on biofilm formation of Shewanella oneidensis MR-1. Secondary flows are important in many natural and artificial systems, but few studies have investigated their role in biofilm formation. To direct secondary flows in the creeping flow regime, where the Reynolds number is low, we flow microbe-laden culture through microscale confinement features. We demonstrate that these confinement features can result in pronounced changes in biofilm dynamics as a function of the fluid flow rate.