Identifying industrial food foam structures by 2D surface image analysis and pattern recognition

Bubbles are fundamental structural elements in several food products modulating density, rheology, texture, appearance and mouthfeel. Foams and aerated structures are characterized by their gas content, stability, bubble size and distribution. However, these measures alone cannot fully describe the complexity of bubble-containing structures. We have used three image analysis methods (Euler characteristic, Minkowski fractal and image texture) to characterize foam structure, and canonical and Bayesian discriminant analysis to identify/classify different foam architectures. This work describes results of this methodology on liquid foams stabilized by proteins at varying concentration and pH levels. Results indicated that groups of three structural parameters (among the 57 calculated) could successfully identify foam structures with different characteristics but unfortunately no single set of features could be used ubiquitously. Additional foam structure information as determined in this work can help to better understand these systems and the impact of bubbles on the physical properties of aerated foods.     

新型功率半导体结构使可持续能源成为可能

最新估计表明,到2050年我们所需要的能源可能会达到现有能源的两倍。矿物燃料的有害影响和隐约出现的短缺促使人们最近开始加速寻找环境友好型、可持续发展的新能源。     

Assessment of texture stationarity using the asymptotic behavior of the empirical mean and variance.

Given textured images considered as realizations of 2-D stochastic processes, a framework is proposed to evaluate the stationarity of their mean and variance. Existing strategies focus on the asymptotic behavior of the empirical mean and variance (respectively EM and EV), known for some types of nondeterministic processes. In this paper, the theoretical asymptotic behaviors of the EM and EV are studied for large classes of second-order stationary ergodic processes, in the sense of the Wold decomposition scheme, including harmonic and evanescent processes. Minimal rates of convergence for the EM and the EV are derived for these processes; they are used as criteria for assessing the stationarity of textures. The experimental estimation of the rate of convergence is achieved using a nonparametric block sub-sampling method. Our framework is evaluated on synthetic processes with stationary or nonstationary mean and variance and on real textures. It is shown that anomalies in the asymptotic behavior of the empirical estimators allow detecting nonstationarities of the mean and variance of the processes in an objective way.     

Sensibilité et spécificité de l'Indice de stress parental face à des situations de mauvais traitements d'enfants.

Tested the discriminant validity of the Parenting Stress Index (PSI; R. R. Abidin, 1995) with a sample composed of maltreating and nonmaltreating mothers with a low SES. Results support the sensitivity and specificity of the PSI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antigen presentation by MHC class II molecules: invariant chain function, protein trafficking, and the molecular basis of diverse determinant capture

Major histocompatibility complex class II molecules are heterodimeric integral membrane proteins whose primary function is the presentation of antigenic peptides derived from proteins entering the endocytic pathway to CD4+ T lymphocytes. To accomplish this physiologic function, class II molecules must assemble in the secretory pathway without undergoing irreversible ligand association at that site, traffic efficiently to the endocytic pathway, and productively interact with protein ligands in these organelles before their ultimate expression on the plasma membrane. Here we review our work describing how invariant chain promoters the assembly and transport process, the complex itinerary of class II-invariant chain complexes through the endocytic pathway, the role of large protein fragments as substrates for class II binding, and the existence of a second pathway for antigen capture by mature class II molecules that complements that involving newly synthesized dimers. We integrate these observations into a coherent model for the operation of a class II-dependent antigen processing and presentation system able to capture diverse antigenic determinants present in proteins of varying structure.     

Morphological changes of human skin cells exposed to a DC electric field in vitro using a new exposure system

The human skin contains a physiological battery that could be implicated in the healing process, by creating an endogenous electric field. Skin cells undergo morphological changes in response to an external DC electric field (EF). We found that fibroblasts reorient their cell bodies in a manner perpendicular to the EF direction, for normal and above physiological intensities. Actin and tubulin filaments (cytoskeleton proteins) follow the same pattern of reorientation. Keratinocytes tend to elongate in the same direction, although to a lesser extent. The study of the response of human skin cells to an external EF is a first step toward a better understanding of the mechanisms involved in wound healing and eventually toward the improvement of wound repair.     

Capsulectomy: a cure for the page kidney

Hypertension is a known complication after renal trauma. The cause of posttraumatic hypertension can be renal scarring, infarction, hydonephrosis, infection, vascular injury, and parenchymal compression. The authors report on the case of a 16-year-old boy who experienced hypertension after blunt renal trauma. He had a dense fibrous pseudocapsule causing renal parenchymal compression, which lead to hypertension, a Page kidney. Evaluation with computed tomographic (CT) scan, radioisotope renal scan, renal Doppler, and angiogram confirmed the diagnosis. Removal of the renal capsule and the constricting fibrous pseudocapsule was curative.     

Burst pressure prediction of polyamide pipes

The maximum pressure borne by a pressurized polymer pipe is a fundamental factor in the applications. This paper is aimed at showing that this factor can be calculated using a minimum knowledge of the mechanical behavior of the polymer. According to previous works developed for metal pipes, ductile rupture proceeds by a plastic instability. This theory is reviewed in the paper. A close form equation provides the burst pressure or critical hoop stress as a function of initial dimensions of the pipe and tensile test data. The model is checked against burst experiments performed on plasticized polyamide 12 pipes. The agreement is good at room and elevated temperature. Finally, generalization to other polymers is discussed. This approach can be used as a rapid method of assessing the performance of new polymer compounds.