Characterisation of lactic acid bacteria isolated from fermented milk "laban"

The technological properties of 96 lactic acid bacteria isolated from Lebanese traditional fermented milk "laban" were characterised. They were classified by phenotypic and biochemical analyses as Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, thus indicating that laban is a fermented milk similar to yogurt. Most strains of L. bulgaricus (87.5%) exhibited a high acidification activity, whereas strains of streptococci showed low acidification ability. 33.3% of streptococci strains and 25% of lactobacilli strains displayed similar acidification performances as European strains. Results obtained for syneresis, texture and rheological parameters led us to consider that isolated strains were not low polymer-producing strains. Some of them displayed interesting characteristics such as low syneresis and high values for rheological parameters. The major flavour compounds found in pure cultures were acetaldehyde, acetone, 2-butanone, dimethyl disulfide, acetoin, 2,3-butanedione, 2,3-pentanedione, and acetic, hexanoic and butanoic acids. Acetaldehyde (7.4%) and organic acids (48.3%) were mainly produced by L. bulgaricus strains, whereas streptococci cultures contained high relative levels of 2,3-butanedione and acetoin, which represented around 82% of the total flavour compounds. Finally, strains isolated from laban samples exhibited different technological properties than those used in yogurt production, thus conferring specific characteristics to this product.     

Bioefficacy of essential and vegetable oils of Zanthoxylum xanthoxyloides seeds against Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae)

Experiments were conducted in the laboratory to evaluate the bioefficacy of essential and vegetable oils of Zanthoxylum xanthoxyloides (Rutaceae) against Acanthoscelides obtectus (Coleoptera: Bruchidae). The chemical composition of the essential oil and the fatty acid composition of the vegetable oil extracted from the seeds of Z. xanthoxyloides were determined. The insecticidal activities of these oils and the associated aromatized clay powder were evaluated against A. obtectus. Both oils were strongly repellent (100% repellency at 0.501 μl/cm2 essential oil and 3.144 μl/cm2 vegetable oil) and highly toxic (LC?? = 0.118 μl/cm2 for essential oil) to this beetle after contact on filter paper. The vapors of the essential oil were highly toxic to adult insects (LC?? = 0.044 μl/cm3), and the aromatized powder made from clay and essential oil was more toxic (LD?? = 0.137 μl/g) than the essential oil alone (LD?? = 0.193 μl/g) after 2 days of exposure on a common bean. Both oils greatly reduced the F? insect production and bean weight loss and did not adversely affect the bean seed viability. In general, the results obtained indicate that these plant oils can be used for control of A. obtectus in stored beans.     

Au delà d’une vitesse de groupe: vitesse d’onde et vitesse de signal

A radiated fieldalways appears in a dual, spatial and temporal, aspect. Its spatial one is the wave the author should observe at a given time. Its temporal one is the signalhe receive at a given point. The aim of this paper is then to determine bulk velocities of both signal and wave — without any limiting assumption on their spectral widths — in case the field is being radiated thru a dispersive medium. A realistic criterion is first adopted that enables an accurate measurement of the instant position of the wave, by means of a definite space-marker (the wave center. The same criterion also leads to a similar timemarker (the signal center,) that will be used in measuring the receiving time of the signal. By studying the motion of these markers, an operator U spontaneously appears beside the phase velocity This operator has the same analytical expression as the usual group/signal velocity of a wave packet. Therefore U should be also called group velocity. Both group and phase velocities depend on the transmitting medium only. To the travelling wave then corresponds an uniform motion of its wave center, with some wave velocity. The latter consists of the mean of operator U in a state which is associated with the wave structure at the time origin. To the signal, when received by a fixed transductor, also corresponds some signal velocity. Its value is the inverse of the mean of operator U ^?1 in a state which is associated with the signal structure at the transmitter. Thus, wave velocity and signal velocity not only depend on the transmitting medium, but depend on the emitted signal form too. However both of them become identified with the group velocity U in the particular case of a very narrow spectrum. Thus agreeing with the usual wave packet. In such a case the group velocity turns out to be the velocity of the very marker that belongs to the amplitude of the transmitted analytic signal. Such an approach also enables us to describe signal distortion in a dispersive medium. By analogy, it leads to relating that distortion to Fresnel diffraction. Outside anomalous zones, the above properties are roughly maintened when attenuation is taken into account in relation to dispersion.     

Polymer electrolytes

Summary The room temperature conductivity of lithium salts dissolved in polyethylene oxide, proposed as polymer electrolytes, is shown to decrease drastically upon storage. The crystallization process, which is responsible for that ageing, can be blocked, if two further components are added : an elastomer copolymer butadiene-acrylonitrile and a macromer of polyoxyethylene. In addition, a crosslinking process must be carried out.     

Visualizing music similarity: clustering and mapping 500 classical music composers

Scientometrics - This paper applies clustering techniques and multi-dimensional scaling (MDS) analysis to a 500?×?500 composers’ similarity/distance matrix. The objective is...     

A Reconfigurable Index FLASH Memory tailored to Seed-Based Genomic Sequence Comparison Algorithms

Genomic sequence comparison algorithms represent the basic toolbox for processing large volume of DNA or protein sequences. They are involved both in the systematic scan of databases, mostly for detecting similarities with an unknown sequence, and in preliminary processing before advanced bioinformatics analysis. Due to the exponential growth of genomic data, new solutions are required to keep the computation time reasonable. This paper presents a specific hardware architecture to speed-up seed-based algorithms which are currently the most popular heuristics for detecting alignments. The architecture regroups FLASH and FPGA technologies on a common support, allowing a large amount of data to be rapidly accessed and quickly processed. Experiments on database search and intensive sequence comparison demonstrate a good cost/performance ratio compared to standard approaches.

The mechanism of morphogenesis in a phase-separating concentrated multicomponent alloy

What determines the morphology of a decomposing alloy? Besides the well-established effect of the nucleation barrier, we demonstrate that, in a concentrated multicomponent Ni(Al,Cr) alloy, the details of the diffusion mechanism strongly affect the kinetic pathway of precipitation. Our argument is based on the combined use of atomic-scale observations, using three-dimensional atom-probe tomography (3D APT), lattice kinetic Monte Carlo simulations and the theory of diffusion. By an optimized choice of thermodynamic and kinetic parameters, we first reproduce the 3D APT observations, in particular the early-stage transient occurrence of coagulated precipitates. We then modify the kinetic correlations among the atomic fluxes in the simulation, without altering the thermodynamic driving force for phase separation, by changing the vacancy-solute interactions, resulting in a suppression of coagulation. Such changes can only be quantitatively accounted for with non-zero values for the off-diagonal terms of the Onsager matrix, at variance with classical models.     

Diffuse interstitial pneumopathy associated with limited Sj?gren's syndrome (author's transl)

Diffuse interstitial pneumopathy was found to be associated with limited Sj?gren's syndrome (i.e. without connective tissue involvement) in 5 women aged from 48 to 83 years. The respiratory symptoms (dyspnoea, unproductive cough and crepitations) appeared before the dry-eye-and-mouth syndrome was diagnosed in two patients and several years afterwards in three. Respiratory function studies showed a mixed restrictive and obstructive syndrome, perturbed Co transfer and increased total expiratory airways resistance. These changes reflected the underlying pathology, as revealed by bronchial and lung biopsies, which consisted of lymphocyte and plasmocyte infiltration and fibrosis of the interalveolar septa, peribronchial spaces and bronchial glands. Abnormal respiratory function tests in 5 other patients without any respiratory symptom suggest that subclinical and subradiological lesions of the lungs and bronchi are not uncommon in Sj?gren's syndrome.     

Salmeterol compared with slow-release terbutaline in nocturnal asthma. A multicenter, randomized, double-blind, double-dummy, sequential clinical trial. French Multicenter Study Group

The aim of the multicenter, randomized, double-blind, double-dummy, parallel-group clinical trial with a 2-week treatment period was to compare the efficacy and safety of salmeterol (50 micrograms twice daily) with slow-release (SR) terbutaline (5 mg orally, twice daily) in nocturnal asthma. A total of 159 asthmatic adults (FEV, 50-90% of predicted value; sex ratio: 0.87) with at least two nocturnal awakenings during a 7-d run-in period was included in the study. Patients were centrally randomized with a national computer network (Minitel). The main variable (number of awakening-free nights during the last week of treatment) was analyzed according to a sequential method with the one-sided triangular test. The number of awakening-free nights (+/- SD) was significantly higher in the salmeterol group: 5.3 +/- 2.4 vs 4.6 +/- 2.3 (P = 0.006). Salmeterol was significantly more effective than SR-terbutaline in the following factors: number of patients without any awakening during the last week of treatment (50% vs 27%, P = 0.003), mean morning PEF (351 +/- 109 l/min-1 vs 332 +/- 105 l/min-1, P = 0.04), PEF diurnal variation 6 +/- 10% vs 11 +/- 12%, P = 0.01), overall assessment of efficacy by the patient and the investigator (P = 0.001 and 0.005, respectively), and daily rescue salbutamol intakes (P = 0.004). In the salmeterol group, significantly fewer patients reported adverse events (16% vs 29%, P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)