Inferring the left ventricle dynamical behavior using a free-form deformations model

A computational 4D (3D + time) model for simulating the dynamical shape of the left ventricle (LV) based on free-form deformations (FFD) techniques is described. The simulation model is useful as a teaching tool for understanding the normal left ventricle motion. The model is also useful for initializing 3D segmentation algorithms and for understanding the relation between pathologies and variation of parameters defining the ventricular function. Validation of this computational model is performed by synthesizing 4D sequences of the left ventricle, comprising the interval going from end-systole to end-diastole. From the resulting 4D shapes, several mechanical parameters such as the left ventricle volume, the radial contraction and torsion are calculated and compared with results of works previously reported based in MR-tagging images. A comparison is also performed with respect to mechanical parameters extracted from the additional time instants in the same multislice computerized tomography (MSCT) database used for extracting the LV wall surfaces required for initialization. First results show a good match between parameters compared.     

Adaptive linear minimum mean square error restoration: influence on hyperspectral detection strategy

In this paper, we consider the problem of multichannel restoration. Current multichannel least squares restoration filters assume the separability of the signal covariance, which describes the between‐channel and within‐channel relationships. We propose a new solution for a multichannel restoration scheme, the Adaptive Linear Minimum Mean Square Error (ALMMSE), based on a local signal model, without the hypothesis of spectral and spatial separability. The proposed filter is developed to be used as a preprocessing step for detection in hyperspectral imagery. Tests on real data show that the proposed filter enables us to enhance detection performance in target detection and anomaly detection applications with the well‐known hyperspectral imagery detection algorithms AMF and RX. The comparison with detection results, after classical restoration methods, shows the superiority of the proposed approach for hyperspectral images.     

Plasma‐beam alignment of passive liquid crystals (Invited Paper)

Abstract— A plasma‐beam process, developed for the alignment of liquid crystals (LC) in electro‐optic applications, has been successfully applied to align “non‐standard” LC, such as crystalline materials with LC phases at elevated temperatures and reactive mesogenes. In addition to the high alignment quality of the materials, there is no need for an intermediate layer between the substrate and the LC layer. Furthermore, the construction of our source simplifies the alignment procedure of large‐area rigid substrates and the roll‐to‐roll processing of flexible films. This method opens new horizons for optical retarders and polarizers, as well as anisotropic semiconducting films for organic electronics.     

Preface: Volume 30, Issue 4

The characteristics of logic programming languages both necessitate and motivate innovative approaches in the areas of user environments and programming tools. The Tenth Workshop on Logic Programming Environments provided a forum for researchers, developers, programmers, and users to exchange ideas and results on all aspects of environments for logic programming. Contributions coming from Europe, the USA, Australia and Japan addressed debugging (4x), vizualization, graphical spreadsheets, and automated documentation. Coming from a different background, Clinton Jeffery, invited speaker, presented a monitoring environment for C which, we hope, was inspiring for the logic programming community.

A special thanks to Enrico Pontelli, ICLP'99 workshop coordinator. Thanks also to Francisco Bueno, Manuel Carro, Erwan Jahier, Sarah Mallet, Julio Marino, and Olivier Ridoux who helped with paper reviewing.     

Models and methods for frequency assignment with cumulative interference constraints

In this paper, a realistic modeling of interferences for frequency assignment in hertzian telecommunication networks is presented. In contrast with traditional interference models based only on binary interference constraints involving two frequencies, this new approach considers the case of cumulative disruptions that are modeled through a unique non‐binary constraint. To deal with these complex constraints, we propose extensions of classical integer linear programming formulations. On a set of realistic instances, we propose hybrid constraint programming and large neighborhood search solution methods to solve minimum interference and minimum span frequency assignment problems. We compare their performances with those of existing heuristics. Finally, we show how the end‐user benefits from using the cumulative model instead of the traditional one.     

Personalized Development of Antisense Oligonucleotides for Exon Skipping Restores Type XVII Collagen Expression in Junctional Epidermolysis Bullosa

Intermediate junctional epidermolysis bullosa caused by mutations in the COL17A1 gene is characterized by the frequent development of blisters and erosions on the skin and mucous membranes. The rarity of the disease and the heterogeneity of the underlying mutations renders therapy developments challenging. However, the high number of short in-frame exons facilitates the use of antisense oligonucleotides (AON) to restore collagen 17 (C17) expression by inducing exon skipping. In a personalized approach, we designed and tested three AONs in combination with a cationic liposomal carrier for their ability to induce skipping of COL17A1 exon 7 in 2D culture and in 3D skin equivalents. We show that AON-induced exon skipping excludes the targeted exon from pre-mRNA processing, which restores the reading frame, leading to the expression of a slightly truncated protein. Furthermore, the expression and correct deposition of C17 at the dermal–epidermal junction indicates its functionality. Thus, we assume AON-mediated exon skipping to be a promising tool for the treatment of junctional epidermolysis bullosa, particularly applicable in a personalized manner for rare genotypes.     

Effect of bacterial interactions on the spoilage of cold-smoked salmon

Cold-smoked salmon is a lightly preserved fish product in which a mixed microbial flora develops during storage and where the interactive behaviour of micro-organisms may contribute to their growth and spoilage activity. The aim of this study was to assess the effect of the bacterial interactions between the main species contaminating the cold-smoked salmon on bacterial growth, chemical and sensory changes, and spoilage. First, Carnobacterium piscicola, Photobacterium phosphoreum, Lactobacillus sakei, Vibrio sp., Brochothrix thermosphacta and Serratia liquefaciens-like were inoculated as pure cultures on sterile cold-smoked salmon. All bacterial species grew well; Vibrio sp. was the fastest and L. sakei strains developed very rapidly as well with a high maximum cell density on cold-smoked salmon blocks (up to 10(9) cfu g(-1) after 10 days at 8 degrees C). Based on sensory analysis, Vibrio sp. was identified as non-spoilage bacteria, C. piscicola as very lightly and B. thermosphacta as lightly spoiling. L. sakei and S. liquefaciens-like were found to be the most spoiling bacteria. Secondly, C. piscicola and L. sakei, two species frequently occurring in the lactic flora of the product, were inoculated together and each of them in mixed cultures with respectively P. phosphoreum, Vibrio sp., B. thermosphacta, and S. liquefaciens-like. The growth of L. sakei was shown to strongly inhibit most of the co-inoculated strains i.e. P. phosphoreum, B. thermosphacta, S. liquefaciens-like and, to a lesser extent, Vibrio sp. The growth of C. piscicola seemed to be enhanced with B. thermosphacta and to develop earlier with P. phosphoreum and Vibrio sp. Conversely, S. liquefaciens-like and P. phosphoreum were weakly inhibited by C. piscicola. The main observation resulting from the sensory evaluation was the delay in the appearance of the spoilage characteristics in the mixed cultures with L. sakei, in particular L. sakei/ S. liquefaciens-like. On the other hand, the spoilage activity of the non-spoiler strains Vibrio sp. or the moderate spoilage strains B. thermosphacta and C. piscicola was increased when they were associated together. It is concluded that the spoilage behaviour of micro-organisms in mixed culture is significantly different from pure culture and explain the difficulty to find robust quality indices for this product.     

An event-related potential (ERP) study of musical expectancy: Comparison of musicians with nonmusicians.

Musicians and nonmusicians listened to musical phrases that were either selected from the classical repertoire or composed for the experiments. The phrases ended either congruously or with a nondiatonic, diatonic, or rhythmic violation. Percentage of correct responses was analyzed in Exp 1, and event-related potentials (ERPs) were recorded in Exps 2 and 3. Musicians performed better than nonmusicians in recognizing familiar musical phrases and classifying terminal notes. The differences found as a function of expertise were larger for unfamiliar than for familiar melodies. The ERPs to the end notes differed both in terms of amplitude and latency between musicians and nonmusicians, and as a function of participants' familiarity with the melodies and type of violation. Results show that expertise influences the decisional rather than the purely perceptual aspects of music processing and that ERPs can provide important insight into the study of music perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What is at stake in the construction and use of credit scores?

Most of statistical studies on credit scoring focus on scores construction. It is more unusual that they link the statistical technics with a detailed analysis of the users’ requirements regarding the properties of these tools. Concerning companies’ failure the users are financial analysis experts or bankers in credit risk departments or banking supervisors. The increasing need for better control of credit risk by banks has led to a stepping-up of research concerning credit scoring. In the context of the Basel II agreement, the International Banking Committee has stressed the importance of forecasting the expected loss (EL) and, using extreme quantiles, the unexpected loss (UL) for a population of companies, in particular for customers of each commercial bank. In order to do so, it is necessary to estimate the default probability of each company at a given time horizon (PD). The objective of an accurate forecasting gives rise to several needed properties and questions that are presented in Sect. 1. We stress what is at stake in the construction and the use of credit scores. The experience of Banque de France in prudential supervision and the importance of its data files on companies give the possibility to developp a scoring system able to fullfil these needed properties, at least partially. Some principles of credit scoring construction in order to increase the quality of the tool and the accuracy of default probability are presented in Sect. 2. Without leading a complete debate on models’choice we discuss some arguments regarding this choice and we concentrate on comparison between Fisher linear discriminant analysis (LDA) and logistic regression (LOGIT) in Sect. 3. In relation with the early detection of companies default, two pratical uses of a credit scoring system are presented in Sect. 4. Research under way on Banque de France data concentrates on informations that can be extracted from these data on purpose to study how to increase the quality of tools needed by the Basel II agreement. A short overview of this research is given in Sect. 5. “Statistical inference techniques, if not applied to the real world, will lose their import and appear to be deductive exercises. Furthermore, it is my belief that a statistical course emphasis should be given to both mathematical theory of statistics and to application of the theory to practical problems. A detailed discussion on the application of a statistical technique facilitates better understanding of the theory behind the technique.” C. Radhakrishna RAO in Linear Statistical Inference and Its Applications     

Branch and bound algorithms for rate-distortion optimized media streaming

We consider the problem of rate-distortion optimized streaming of packetized multimedia data over a single quality-of-service network using feedback and retransmissions. For a single data unit, we prove that the problem is NP-hard and provide efficient branch and bound algorithms that are much faster than the previously best solution based on dynamic programming. For a group of interdependent data units, we show how to compute optimal solutions with branch and bound algorithms. The branch and bound algorithms for a group of data units are much slower than the current state of the art, a heuristic technique known as sensitivity adaptation. However, in many real-world situations, they provide a significantly better rate-distortion performance.