Glucosinolates in etiolated sprouts of sea-kale (Crambe maritima L)

Sea-kale, a long-forgotten vegetable, could make a resurgence due to its culinary attractiveness. Unfortunately, as with most cruciferous plants, its quality may be reduced owing to the presence of glucosinolates, mainly known for their antinutritional properties. The aim of this study was to evaluate the actual amount of these compounds found in edible sea-kale sprouts, using qualitative and quantitative analysis by liquid chromatography carried out after treatment by freezing, blanching and cooking. Before treatment, the quantity of glucosinolates, of which more than 80% is represented by epi-progoitrin, was found between 5.4 and 7.3 μmol g^?1 of fresh matter. In this study, freezing then thawing causes a nearly complete decomposition of glucosinolates into nonidentified compounds which are most probably 5-vinyloxazolidine-2-thionc and nitrites. Cooking for 4 min (blanching) brings about through leaching, a nearly 30% reduction. A greater decrease (76%) can be obtained with a cooking time of 20 min. The amount of glucosinolates found in sea-kale was compared with that of other commonly used cruciferous vegetables and there appears to be practically no risk when consumed on a monthly basis. At present sea-kale remains a desired vegetable in gastronomical dishes.     

Membranes,minerals, and proteins of developing vertebrate enamel

Developing tooth enamel is formed as organized mineral in a specialized protein matrix. In order to analyze patterns of enamel mineralization and enamel protein expression in species representative of the main extant vertebrate lineages, we investigated developing teeth in a chondrichthyan, the horn shark, a teleost, the guppy, a urodele amphibian, the Mexican axolotl, an anuran amphibian, the leopard frog, two lepidosauria, a gecko and an iguana, and two mammals, a marsupial, the South American short-tailed gray opossum, and the house mouse. Electron microscopic analysis documented the presence of a distinct basal lamina in all species investigated. Subsequent stages of enamel biomineralization featured highly organized long and parallel enamel crystals in mammals, lepidosaurians, the frog, and the shark, while amorphous mineral deposits and/or randomly oriented crystals were observed in the guppy and the axolotl. In situ hybridization using a full-length mouse probe for amelogenin mRNA resulted in amelogenin specific signals in mouse, opossum, gecko, frog, axolotl, and shark. Using immunohistochemistry, amelogenin and tuftelin enamel proteins were detected in the enamel organ of many species investigated, but tuftelin epitopes were also found in other tissues. The anti-M179 antibody, however, did not react with the guppy and axolotl enameloid matrix. We conclude that basic features of vertebrate enamel/enameloid formation such as the presence of enamel proteins or the mineral deposition along the dentin-enamel junction were highly conserved in vertebrates. There were also differences in terms of enamel protein distribution and mineral organization between the vertebrates lineages. Our findings indicated a correlation between the presence of amelogenins and the presence of long and parallel hydroxyapatite crystals in tetrapods and shark.     

Hyperthermostable mutants of Bacillus licheniformis {alpha}-amylase: multiple amino acid replacements and molecular modelling

We have identified previously two critical positions for thethermostability of the highly thermostable -amylase from Bacilluslicheniformis. We have now introduced all 19 possible aminoacid residues to these two positions, His 133 and Ala209. Themost favourable substitutions were to Ile and Val, respectively,which both increased the half-life of the enzyme at 80°Cby a factor of 3. At both positions a stabilizing effect ofhydrophobic residues was observed, although only in the caseof position 133 could a clear correlation be drawn between thehydrophobicity of the inserted amino acid and the gain in proteinstability. The construction of double mutants showed a cumulativeeffect of the most favourable and/or deleterious substitutions.Computer modelling was used to generate a 3-D structure of thewild-type protein and to model substitutions at position 209,which lies in the conserved (/ß)₈ barrel domain of-amylase; Ala209 would be located at the beginning of the thirdhelix of the barrel, in the bottom of a small cavity facingthe fourth helix. The model suggests that replacement by, forexample, a valine could fill this cavity and therefore increaseintra- and interhelical compactness and hydrophobic interactions.     

Le programme d’admissibilité avec contraintes de sécurité et coûts de mutations: application aux réseaux de transmission mixtes (analogiques et numériques)

This paper presents a second version of the «feasibility program» (securad)developed by the cnet.This program enables the routing at minimal cost of several thousands of requirements (expressed in circuits or groups of circuits) on very large mixed (analogue and digital) transmission networks, while respecting given capacities and taking into account security constraints and network-rearrangement costs. The authors also describe a procedure for determining lower bounds for the cost of the optimal solution by solving a dual problem, and thus checking the quality of the approximate solutions obtained. This program has already been widely applied to the long-distance transmission network and to large digital metropolitan networks for both short term and medium to long term planning purposes.     

Powered two-wheeler drivers’ crash risk associated with the use of bus lanes

Context

Authorizing powered two-wheeler drivers to drive in lanes reserved to buses is a measure that is sometimes mentioned to improve mobility conditions for these users. But what effect would this measure have on the safety of these users and on the safety of the other users with whom they share the traffic space?

Objective

The objective of this study is to contribute elements to help answer this question. More precisely, the objective is to estimate the risk of having an accident per kilometer driven by powered two-wheeler drivers who drive in bus lanes and to compare this risk with that of powered two-wheeler drivers who drive in general traffic lanes.

Method

Using the bodily injury accidents recorded by the police over two years on 13 roads in the city of Marseille and a campaign of periodical observations of powered two-wheeler traffic, we estimated the risk per kilometer driven by powered two-wheeler drivers who drive in bus lanes and compared it with that of drivers who do not drive in them.

Results

The results show that the risk for powered two-wheeler drivers who drive in bus lanes of being involved in a bodily injury accident is significantly higher than the risk run by drivers who drive in general traffic lanes. For the 13 roads studied, it is on average 3.25 times higher (95% CI: 2.03; 5.21).

Conclusion

In the current situation, powered two-wheeler drivers who drive in bus lanes are less safe than those who drive in general traffic lanes. The analysis of police reports suggests that part of this increased risk comes from collisions between automobile drivers turning right and powered two-wheelers driving in the bus lane who continue straight ahead.     

Improving trochoidal tool paths generation and implementation using process constraints modelling

With the emergence of high dynamic machine tools equipped with performing NC controllers, new types of strategies have risen to meet the demands associated to high-speed milling process. Among them, trochoidal tool paths are applied in rough machining applications. In this paper several improvements for their implementation are proposed. First, maximal radial depth of cut calculation according to tool path parameterization is made. Two interpolation models are tested and compared. The aim is to select the best tool path parameters according to the process constraints. Then, improved tool path generation for pocket milling applications is proposed. An experimental study is performed to validate the proposed approach and study the efficiency of trochoidal tool path implementation for pocket milling applications. The impact of the dynamics of the machine tool is evaluated in particular. The work presented here leads consequently to enhancement of implementation of trochoidal tool paths according to process constraints.     

Ion transport in CLIP: Investigation through conductivity and NMR measurements

The study deals with the electrochemical and physico-chemical characterizations of new proton-conducting ionic liquids. Through the use of several amines and perfluorinated acids, it attempts to define the most appropriate ionic liquids for use in high temperature PEMFCs. In addition to the usual characterizations based on Pulsed Field Gradient NMR and conductivity measurements, NMR correlation techniques NOESY, HOESY and COSY experiments are used to characterize the interactions and spatial proximities of ionic liquid species.     

First insights of Cr speciation in leached Portland cement using X-ray spectromicroscopy

X-ray spectromicroscopy has been successfully applied to determine the evolution of the Cr oxidation state in Portland cement during leaching experiments. To our knowledge, this is the first study that demonstrates the possibility to study the chromium oxidoreduction phenomena in cement materials at natural Cr concentration (approximately 60 ppm) and at the micron scale. Line scans of Cr for Cr(VI) doped (2000 ppm) and undoped samples indicate that the altered layer (0-1000 microm from the surface) is characterized by a lower amount of Cr as compared to the core part, whereas an accumulation appears in the intermediate region (1000-1300 microm). This Cr-rich interface could correspond to an accumulation of ettringite (3CaO x Al2O3 x 3CaSO4 x 32H2O) as reported by previous works. This mineral exhibits the property to incorporate Cr(III) and Cr(VI) by replacement of aluminum and sulfate, respectively, in the structure. The most surprising result concerns the evolution of the Cr(VI)/Cr(tot) ratio along the line spectra, which is constant from the altered layer to the core (both for doped and undoped samples). This means thatthe same amounts of Cr(VI) and Cr(tot) are released during leaching. Even for the undoped sample, Cr(VI) was detected in the altered layer at 40 microm from the surface. This result is not in perfect agreement with literature, which usually states that Cr(VI) is mainly leached out. Although this result must be confirmed, it clearly indicates that Cr(VI) may be less mobile than predicted by models. An attempt is made to identify potential Cr(VI) fixation phases.