High-throughput evaluation of antioxidant and pro-oxidant activities of polyphenols with thymidine protection assays

A recently reported high-throughput screening strategy has been applied to the rapid selection of new water-soluble antioxidants that display strong protective activities. Based on a competitive immunoassay, a triple-screening procedure was used to evaluate the ability of different compounds to protect thymidine under different oxidative stresses. The pro-oxidant effect of norbadione A in the presence of iron was observed, while some pulvinic acid derivatives proved strongly protective during gamma radiolysis, UV irradiation, and Fenton-like oxidation.     

Characterisation of PSE zones in semimembranosus pig muscle

Pig semimembranosus muscles, sampled from normal hams or from PSE-zones of defective hams, were analysed by histochemistry and electrophoretic techniques. PSE zones were characterised by a disorganisation of fibre alignment and a significant increase of inter fibre spacing (26.2% vs. 16.9%, p<0.05). Protein solubility was significantly lower in defective muscle (55.4 vs. 91.5mg/g, p<0.001). SDS-PAGE evidenced in such samples a lower abundance of the 97, 40 and 26kDa bands in the sarcoplasmic fraction and a higher abundance of the 97, 58, 34, 31, 15 and 11kDa bands in the myofibrillar fraction. Intensity of the MHC band (200kDa) was lower in PSE zone samples. By 2-D electrophoresis, it was shown that troponin T, MLC 1 and alpha-crystallin were less proteolysed in defective muscles, while creatine kinase fragments were more represented. One form of HSP 27 was absent from PSE zone samples. Overall, meat from PSE-zones and fast pH fall-PSE meat show numerous histological and biochemical similarities, particularly in their protein characteristics.     

Resource Allocation and Wireless Scheduling Scheme for a HiperLAN/2 System

In this paper, a dynamic resource allocation scheme for a wireless local area network system is presented. It aims at enforcing the Quality of Service requirements of the applications that are carried on the wireless link even when errors occur on it. The allocation takes benefit from the coexistence of connections that have different QoS tolerances so that, when facing errors, the bandwidth allocated to the more tolerant connections could be reduced and attributed to the connection with more stringent QoS requirements to perform retransmissions. For that purpose, two classes of Quality of Service are considered that are related to Constant Bit Rate traffics and best-effort traffics. The scheduling framework is then based on a hierarchical rate-based fair queuing algorithm and is extended in order to cope with error. To illustrate its operation, the proposed scheme is applied to the ETSI HiperLAN/2 WLAN. Some simulation results are reported and show the impact of the scheduling principles on best-effort traffics such as TCP applications and its actual benefits for CBR traffic. The efficiency of the proposed mechanism is evaluated using measurement of delays and throughputs at Data Link Layer level. The aim of this paper is not so much to prove the fairness of this mechanism but rather its ability to guarantee negotiated services required by heterogeneous applications.Christophe Mangin is a research engineer at Mitsubishi Electric ITE-TCL. He received degrees in Electrical Engineering from Institut National des Sciences Appliquées (INSA), Rennes, France, in 1988, and in VLSI architecture from Université Paris VI, in 1989. From 1989 to 1991, he was with ALCATEL SEL, Stuttgart, Germany, where he was involved in parallel DSP design for image processing. From 1991 to 1999, he worked at France Telecom R&D, Lannion, France, in the field of packet switch/router architectures, ATM resource management techniques, and Internet network architecture. In 1999, he joined Mitsubishi Electric ITE’s Telecommunication Laboratory, Rennes, France. His present research interests include broadband wireless systems and wireless-wired network interoperability with a special focus on quality of service mechanisms for Internet applications in heterogeneous networks.Gwillerm Froc received the PhD degree in Physics in 1997 from the University of Paris XI. At that time, his research interests were related to the optical telecommunications field. Then, he worked at France Telecom R&D on reliable multicast protocols on IP for satellite broadcasting. He joined Mitsubishi Electric ITE in 2001. His main scientific and engineering interests now deal with performances and modelling of wireless systems. They currently focus on MAC protocols.Romain Rollet received his M.Sc. in electronics and computer engineering from the Ecole Supérieur d’Electricité (Supelec), France in 1998. In 2000, he joined Mitsubishi Electric Telecom Laboratory in Rennes where he has participated to the development and implementation of a complete HiperLAN/2 prototype. His current research areas are mostly related to Data Link layer and interactions between physical and MAC layers in future WLAN systems. He is the author or co-author of several pending patents.     

Increasing the Link Utilization in IP over WDM Networks Using Availability as QoS

In this paper, we solve a mapping problem related to supporting two service classes that are differentiated based on their level of protection. The first class of service, called Fully Protected (FP), offers end-users a guarantee of survivability in the case of a single failure; all FP traffic is protected using either a 1:1 or 1 + 1 protection scheme at the WDM layer. The second class of service, called Best-Effort Protected (BEP), is not protected; instead restoration at the IP layer is provided. When a failure occurs, the network restores as much BEP traffic as possible, and thus BEP traffic does not receive any specific guarantees. The FP service class mimics what Internet users receive today. The BEP traffic is designed to run over the large amounts of unused bandwidth that exist in todays Internet. The motivation of this approach is to give carriers a mechanism for increasing the load carried on backbone networks without reducing the QoS received by existing customers. In order to support two such services, the logical links at the IP layer need to be carefully mapped onto primary and backup paths at the optical layer. We incorporate into our mapping problem a number of practical requirements that reflect constraints that carriers face and policies they want to enforce. For example, we allow the FP demand to be specified via a traffic matrix at the IP layer, we include an overprovisioning factor that specifies the portion of each link that must be left unused, and we incorporate a minimal fairness requirement on how the BEP traffic is allocated among connections. Our goal is to quantify how much BEP traffic can be carried in addition to the FP traffic, without impacting the protection quality of the FP traffic even in the case of failure, and without impacting the FP load. We provide two solutions, one is an optimal solution using an Integer Linear Program (ILP) model, and the other is an algorithm based on the Tabu Search (TS) methodology. Our heuristic algorithm allows us to solve this problem for large networks such as those spanning the continental US. We show that by having two such classes of service, the load on a network can be increased by a factor of 4–7 (depending upon the network). We illustrate that even with overprovisioning and fairness requirements (both of which reduce the total possible BEP load carried), we can still typically triple the total network load. We show that the location of the bottleneck can affect whether or not we see a difference in performance between 1:1 or 1 + 1 protection schemes. Our results illustrate the gain in terms of additional BEP load carried that can be obtained simply due to the upgrade of a single link. Our proposal provides carriers a new vehicle for generating revenue by extracting benefit from all the sources of unused bandwidth in networks.     

Targeted comparative proteomics by liquid chromatography-tandem Fourier ion cyclotron resonance mass spectrometry

In proteomics, effective methods are needed for identifying the relatively limited subset of proteins displaying significant changes in abundance between two samples. One way to accomplish this task is to target for identification by MS/MS only the "interesting" proteins based on the abundance ratio of isotopically labeled pairs of peptides. We have developed the software and hardware tools for online LC-FTICR MS/MS studies in which a set of initially unidentified peptides from a proteome analysis can be selected for identification based on their distinctive changes in abundance following a "perturbation". We report here the validation of this method using a mixture of standard proteins combined in different ratios after isotopic labeling. We also demonstrate the application of this method to the identification of Shewanella oneidensis peptides/proteins exhibiting differential abundance in suboxic versus aerobic cell cultures.     

Coupled parametric active contours

We propose an extension of parametric active contours designed to track nonoccluding objects transiently touching each other, a task where both parametric and single level set-based methods usually fail. Our technique minimizes a cost functional that depends on all contours simultaneously and includes a penalty for contour overlaps. This scheme allows us to take advantage of known constraints on object topology, namely, that objects cannot merge. The coupled contours preserve the identity of previously isolated objects during and after a contact event, thus allowing segmentation and tracking to proceed as desired.     

Heat Capacity of Sodium Silicate Liquids

Drop calorimetry measurements for four Na₂0-Si0₂ liquids indicate that, to within ±0.5%, the heat capacities are temperature-independent between 900 and 1800 K and additive functions of composition for liquids containing from 50 to 100 mol% Si0₂. In this composition interval, the partial molar heat capacities of Si0₂ and Na₂0 are 81.37 and 100.6 J /mole-K, respectively.     

Catalytic membrane reactor for Suzuki‐Miyaura C−C cross‐coupling: Explanation for its high efficiency via modeling

A polymeric catalytic membrane was previously prepared that showed remarkable efficiency for Suzuki‐Miyaura C‐C cross‐coupling in a flow‐through configuration. A mathematic model was developed and fitted to the experimental data to understand the significant apparent reaction rate increase exhibited by the catalytic membrane reactor compared to the catalytic system under batch reaction conditions. It appears that the high palladium nanoparticles concentration inside the membrane is mainly responsible for the high apparent reaction rate achieved. In addition, the best performance of the catalytic membrane could be achieved only in the forced flow‐through configuration, that, conditions permitting to the reactants be brought to the catalytic membrane by convection. © 2016 American Institute of Chemical Engineers AIChE J, 63: 698–704, 2017     

In situ study on microwave sintering of ZTA ceramic: Effect of ZrO2 content on densification,hardness, and toughness

Better understanding of the effect of multimode‐microwave sintering of zirconia‐toughened alumina (ZTA) was investigated. A comparative dilatometric analysis was conducted between conventional and microwave heating processes, to clarify the influence of zirconia on the densification of ZTA under electromagnetic field. The thermal gradient on sample measurements indicates the change to the microwave volumetric heating is improved by zirconia which adsorbs microwave energy better, thus acting as a susceptor. The most beneficial effect on microstructure, toughness, and hardness were observed at the optimal zirconia content of 10 vol%. The results with both microwave and conventional sintering illustrate the strengthening effect on the composite by zirconia. Of special interest, multimode microwave sintering creates a finer homogeneous microstructure, with resulting hardness and toughening comparable to those obtained for conventional sintering, as well as improved densification, and at lower cost.