Comparison of the water-soluble carbohydrate composition and fructan structures of Agave tequilana plants of different ages

The composition of water-soluble carbohydrates from Agave tequilana plants of 2, 4 and 6½ years were compared by HPLC, HPAEC-PAD, MALDI-TOF-MS and GC–MS. The plants of 2 years exhibited the highest levels of free monosaccharide and low molecular weight fructans (DP 3–DP 6) with potential application as prebiotics. A maximum of fructan polymerisation was achieved at 4 years with mean DP from 3 to 30, then it was decreased at 6½ years with mean DP from 4 to 24. The linkage analysis showed an increase and decrease in the branching degree from 2 to 6½ years with a maximum at 4 years, correlated to changes in t-β-d-Fruf linkages with increased and decreased synthesis of (2→1) and (2→6)-β-d-Fruf as well as 1,6-di-β-d-Fruf linkages.     

Flying over the reality gap: From simulated to real indoor airships

Because of their ability to naturally float in the air, indoor airships (often called blimps) constitute an appealing platform for research in aerial robotics. However, when confronted to long lasting experiments such as those involving learning or evolutionary techniques, blimps present the disadvantage that they cannot be linked to external power sources and tend to have little mechanical resistance due to their low weight budget. One solution to this problem is to use a realistic flight simulator, which can also significantly reduce experimental duration by running faster than real time. This requires an efficient physical dynamic modelling and parameter identification procedure, which are complicated to develop and usually rely on costly facilities such as wind tunnels. In this paper, we present a simple and efficient physics-based dynamic modelling of indoor airships including a pragmatic methodology for parameter identification without the need for complex or costly test facilities. Our approach is tested with an existing blimp in a vision-based navigation task. Neuronal controllers are evolved in simulation to map visual input into motor commands in order to steer the flying robot forward as fast as possible while avoiding collisions. After evolution, the best individuals are successfully transferred to the physical blimp, which experimentally demonstrates the efficiency of the proposed approach. Jean-Christophe Zufferey and Alexis Guanella contributed equally to this work.     

Self-assembling of atomic vacancies at an oxide/intermetallic alloy interface

Oxide layers grown on the surface provide an effective way of protecting metallic materials against corrosion for sustainable use in a broad range of applications. However, the growth of cavities at the metal/oxide interface weakens the adherence of the protective layer and can promote its spallation under service conditions, as observed for alumina layers formed by selective oxidation of aluminide intermetallic alloys used in high-temperature applications. Here we show that direct atomic-scale observations of the interface between an ultrathin protective oxide layer (alumina) grown on an intermetallic titanium aluminide substrate (TiAl) can be performed with techniques sensitive to the topmost atomic layers at the surface. Nanocavities resulting from the self-assembling of atomic vacancies injected at the interface by the growth mechanism of the protective oxide are observed for the first time, bringing new insight into the understanding of the fate of injected cavities in oxidation processes.     

Analysis of DNA Replication by Optical Mapping in Nanochannels

DNA replication is essential to maintain genome integrity in S phase of the cell division cycle. Accumulation of stalled replication forks is a major source of genetic instability, and likely constitutes a key driver of tumorigenesis. The mechanisms of regulation of replication fork progression have therefore been extensively investigated, in particular with DNA combing, an optical mapping technique that allows the stretching of single molecules and the mapping of active region for DNA synthesis by fluorescence microscopy. DNA linearization in nanochannels has been successfully used to probe genomic information patterns along single chromosomes, and has been proposed to be a competitive alternative to DNA combing. Yet this conjecture remains to be confirmed experimentally. Here, two complementary techniques are established to detect the genomic distribution of tracks of newly synthesized DNA in human cells by optical mapping in nanochannels. Their respective advantages and limitations are compared, and applied them to detect deregulations of the replication program induced by the antitumor drug hydroxyurea. The developments here thus broaden the field of applications accessible to nanofluidic technologies, and can be used in the future as part for molecular diagnostics in the context of high throughput cancer drug screening.     

Penetration of nanoparticles through fibrous filters perforated with defined pinholes

This paper presents experimental data for penetration of nanoparticles in the 4–30 nm size range through fibreglass filters perforated with defined pinholes at 5 and 15 cm/s. Results show that, when the filter is damaged, penetration increases with decreasing particle diameter. This lower performance is more significant for filters with high airflow resistance. A model explaining the experimental data has been designed based on balanced, laminar airflow inside the pinhole; these conditions were confirmed by detailed study. The experimental points agreed very closely with this model.     

Coping With Chronic Lower Back Pain: Designing and Testing the Online Tool ONESELF

A website was designed in order to help patients with chronic lower back pain (cLBP) to cope with their condition, relying on the concept of health literacy. A sample of 748 chronic or potentially chronic LBP patients were asked to regularly visit the site for a period of 12 months. The intervention was evaluated quantitatively (both preuse and postuse surveys, logfiles) and qualitatively. Users appear to have taken less painkillers than before in the period they accessed the site. Most users reported that the site contributed to increasing their knowledge, and helped them managing their back pain. Communication with doctors, family, and colleagues improved. Qualitative evaluation showed several positive effects including self‐comprehension, improvement of argumentative abilities, orientation, and self‐confidence.     

On the Pre-oxidation Treatments of Four Commercial Ni-Based Superalloys in Air and in Ar–H<Subscript>2</Subscript>O at 950 °C

The short-term oxidation behaviour of RA 602CA, Inconel 693, Manaurite 40XO and Sumitomo 696, which are four alloys recommended for hydrocarbon processing, was studied both in air and in Ar–H₂O to determine the conditions of pre-oxidation treatments. Regardless of the considered material, the oxidation rate at 950 °C was systematically higher in Ar–H₂O than in dry air. Surface examination of the Al-containing alloys indicated that they were not uniformly oxidized all over the surface. All Al-containing alloys (from 1.6 to 3.2% wt) formed an external protective alumina scale and behaved as alumina-forming alloys in dry air at 950 °C. In contrast, these alloys developed a rate-controlling chromia scale and severe internal oxidation in a H₂O-containing atmosphere. Compared with their oxidation behaviour in air + H₂O, the phenomenon was significantly enhanced in the atmosphere that coupled water vapour with a low oxygen pressure. Consequently, the Al-containing alloys should not be pre-oxidized in a water vapour atmosphere prior to long exposure to a corrosive atmosphere. In contrast, the chromia-forming Al-free 696 alloy exhibited identical oxidation behaviour in both atmospheres, demonstrating that the degradation of this alloy was not significantly affected by water vapour.     

Toward the first nonpeptidic molecular tong inhibitor of wild-type and mutated HIV-1 protease dimerization

Herein we describe the synthesis and HIV-1 protease (PR) inhibitory activity of 16 new peptidomimetic molecular tongs with a naphthalene scaffold. Their peptidic character was progressively decreased. Two of these molecules exhibited the best dimerization inhibition activity toward HIV-1 wild-type and multimutated ANAM-11 proteases obtained to date for this class of molecules (～40?nM for wild-type PR and 100?nM for ANAM-11 PR). Although the peptidic character of one molecular tong was completely suppressed, the mechanism of inhibition and inhibitory potency toward both proteases were maintained.     

Mechanisms of weight maintenance under high- and low-protein, low-glycaemic index diets

Scope: Weight maintenance after intended weight loss is a challenge in an obesogenic environment. In a large multicentre dietary intervention study (DiOGenes), it has recently been demonstrated that a high‐protein/low‐glycaemic index (HP/LGI) diet was slightly more efficient in maintaining weight loss than low‐protein/LGI or high‐GI (LP/LGI or HGI) diets. Here, we use a proteomic approach to assess the molecular mechanisms behind this positive effect. Methods and results: A subset of the most successful (weight loser, n=12) and unsuccessful (weight re‐gainer, n=12) individuals consuming the LGI diets with either high‐ or low‐protein content (HP or LP/LGI), following an initial calorie deficit run‐in weight loss phase, were analyzed at the plasma protein level. Proteomic analysis revealed 18 proteins regulated after 6 months of the dietary weight maintenance phase. Furthermore, 12 proteins were significantly regulated as a function of success rate under an HP diet, arising as candidate biomarkers of mechanisms of successful weight maintenance under an HP/LGI diet. Pregnancy‐zone protein (PZP) and protein S (PROS1) were revealed as novel biomarkers of weight maintenance showing opposite effects. Conclusion: Semantic network analysis of the 12 regulated proteins revealed that under an HP/LGI an anti‐atherogenic effect and alterations of fat metabolism were associated with the success of maintaining the initial weight loss.