Cell surface properties affect colonisation of raw milk by lactic acid bacteria at the microstructure level

Cell localisation in the matrix microstructure of fermented food is important for microbial activity and ripening. To evaluate the importance of physicochemical factors in these phenomena, the physicochemical behaviour of four strains of lactic acid bacteria were investigated after inoculation of raw milk or milk fractions. To discriminate between physicochemical and metabolic properties, media were (i) rapidly acidified to avoid cell division or (ii) bacteria were allowed to ferment milk. To evaluate the impact of milk components, cells were dispersed in protein or fatty globule fractions. From two Lactococcus lactis subsp. lactis biovar. diacetylactis strains selected from their different surface properties investigated in previous studies, after rapid acidification one was encountered in fatty globules and protein gels whereas the other was found in serum and on the surface of globules. After fermentation, the first one formed colonies in the lipid phase or next to it in the whey and the second formed colonies in the protein gel. Strains forming long chains (Lactobacillus bulgaricus and Streptococcus thermophilus) were always found in contact with fatty globules, where they developed. Our results suggest that localisation and subsequent spatial colonisation depend on the physicochemical properties of cell surfaces, on the structure in chains as well as on the metabolic ability to develop on proteins or lipids.     

Applications of power series in computational geometry

A number of algorithms are presented for obtaining power series expansions of curves and surfaces at a point. Some results on the radius of convergence are given. Two applications of series are given:

1. • for curve tracing algorithms, where a truncated series is used to approximate the curve of intersection of two surfaces

2. • to define nth degree geometric continuity, for arbitrary

Modelling and performance comparison of optimal AIGaAs/GaAs DMTs and multichannel HEMTs for power amplification

We present two detailed studies concerning thedmt and the multichannelhemt for power amplifications. Each work comprises a first theoretical part where the structure is optimized by simulating the device. Technological realizations are hence performed at the laboratory. The following measurements give results very encouraging and permit to foresee the superior performance relatively to that of GaAs powermesfet.     

Epstein-Barr virus uses HLA class II as a cofactor for infection of B lymphocytes

Infection of B lymphocytes by Epstein-Barr virus (EBV) requires attachment of virus via binding of viral glycoprotein gp350 to CD21 on the cell surface. Penetration of the cell membrane additionally involves a complex of three glycoproteins, gH, gL, and gp42. Glycoprotein gp42 binds to HLA-DR. Interference with this interaction with a soluble form of gp42, with a monoclonal antibody (MAb) to gp42, or with a MAb to HLA-DR inhibited virus infection. It was not possible to superinfect cells that failed to express HLA-DR unless expression was restored by transfection or creation of hybrid cell lines with complementing deficiencies in expression of HLA class II. HLA class II molecules thus serve as cofactors for infection of human B cells.     

Do native predators feed on non-native prey? The case of round goby in a fluvial piscivorous fish assemblage

We evaluated whether or not the invasive round goby (Neogobius melanostomus) represents an important prey source for seven native fish predators in Lake St. Pierre (St. Lawrence River, Canada). The frequency of occurrence of round goby in the stomach contents of brown bullhead (Ameiurus nebulosus) and channel catfish (Ictalurus punctatus) was very low (< 5%), while for the five other predators, it varied between 22% (yellow perch; Perca flavescens) and 65% (sauger; Sander canadensis). Several competing models linking the probability of occurrence of round goby in stomach contents to variables related to space, physical habitat, biotic interactions and predator size were tested for the five species feeding on round goby. Results indicated that space variables influenced round goby occurrence in stomachs for all species. In addition, physical habitat variables had an influence for sauger and walleye (Sander vitreus); biotic variables had an influence for yellow perch, walleye and sauger; and size had an influence for northern pike (Esox lucius), smallmouth bass (Micropterus dolomieu) and walleye. These results are discussed in light of known biological features of the round goby and native predators studied here and have important implications in terms of understanding round goby invasion success in the Great Lakes–St. Lawrence system.     

DIVCLUS-T: A monothetic divisive hierarchical clustering method

DIVCLUS-T is a divisive hierarchical clustering algorithm based on a monothetic bipartitional approach allowing the dendrogram of the hierarchy to be read as a decision tree. It is designed for either numerical or categorical data. Like the Ward agglomerative hierarchical clustering algorithm and the k-means partitioning algorithm, it is based on the minimization of the inertia criterion. However, unlike Ward and k-means, it provides a simple and natural interpretation of the clusters. The price paid by construction in terms of inertia by DIVCLUS-T for this additional interpretation is studied by applying the three algorithms on six databases from the UCI Machine Learning repository.     

Scattering on a ring of processors

In this note, we prove that the complexity of scattering in an oriented ring of p processors is (p - 1) (β + Lτ) where L is the length of the messages, β the communication startup, and τ the elemental propagation time.     

A method of generating translations of unseen n‐grams by using proportional analogy

In recent years, statistical machine translation has gained much attention. The phrase‐based statistical machine translation model has made significant advancement in translation quality over the word‐based model. In this paper, we attempt to apply the technique of proportional analogy to statistical machine translation systems. We propose a novel approach to apply proportional analogy to generate translations of unseen n‐grams from the phrase table for phrase‐based statistical machine translation. Experiments are conducted with two datasets of different sizes. We also investigate two methods to integrate n‐grams translations produced by proportional analogy into the state‐of‐the‐art statistical machine translation system, Moses.¹ The experimental results show that unseen n‐grams translations generated using the technique of proportional analogy are rewarding for statistical machine translation systems with small datasets. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.