363 research outputs found
Influence of thermal history on the structure and properties of silicate glasses
We studied a set of float glass samples prepared with different fictive
temperature by previous annealing around the glass transition temperature. We
compared the results to previous measurements on a series of amorphous silica
samples, also prepared with different fictive temperature. We showed that the
modifications on the structure at a local scale are very small, the changes of
physical properties are moderate but the changes on density fluctuations at a
nanometer scale are rather large: 12 and 20% in float glass and silica, for
relative changes of fictive temperature equal to 13 and 25% respectively. Local
order and mechanical properties of silica vary in the opposite way compared to
float glass (anomalous behavior) but the density fluctuations in both glasses
increase with temperature and fictive temperature
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Studying Lactoferrin N-Glycosylation.
Lactoferrin is a multifunctional glycoprotein found in the milk of most mammals. In addition to its well-known role of binding iron, lactoferrin carries many important biological functions, including the promotion of cell proliferation and differentiation, and as an anti-bacterial, anti-viral, and anti-parasitic protein. These functions differ among lactoferrin homologs in mammals. Although considerable attention has been given to the many functions of lactoferrin, its primary nutritional contribution is presumed to be related to its iron-binding characteristics, whereas the role of glycosylation has been neglected. Given the critical role of glycan binding in many biological processes, the glycan moieties in lactoferrin are likely to contribute significantly to the biological roles of lactoferrin. Despite the high amino acid sequence homology in different lactoferrins (up to 99%), each exhibits a unique glycosylation pattern that may be responsible for heterogeneity of the biological properties of lactoferrins. An important task for the production of biotherapeutics and medical foods containing bioactive glycoproteins is the assessment of the contributions of individual glycans to the observed bioactivities. This review examines how the study of lactoferrin glycosylation patterns can increase our understanding of lactoferrin functionality
Transforming Basic Robotic Platforms into Easily Deployable and Web Remotely Controllable Robots
International audienceThis paper describes a way to transform basic robotic platforms into Web remotely controllable robots. Our goal is to achieve robot deployment anywhere, at anytime, at low-cost. As soon as full or even restricted Internet access is available (WiFi or 3G), the robot can be deployed and Webcontrolled. The distant user can send commands to the robot and monitor the state of the robot. For example, the distant user can make the robot move and get snapshots taken by the robot
In situ measurements of density fluctuations and compressibility in silica glass as a function of temperature and thermal history
In this paper, small-angle X-ray scattering measurements are used to
determine the different compressibility contributions, as well as the
isothermal compressibility, in thermal equilibrium in silica glasses having
different thermal histories. Using two different methods of analysis, in the
supercooled liquid and in the glassy state, we obtain respectively the
temperature and fictive temperature dependences of the isotheraml
compressibility. The values obtained in the glass and supercooled liquid states
are very close to each other. They agree with previous determinations of the
literature. The compressibility in the glass state slightly decreases with
increasing fictive temperature. The relaxational part of the compressibility is
also calculated and compared to previous determinations. We discussed the small
differences between the different determinations
Internet-based teleoperation: A case study - toward delay approximation and speed limit module
International audienceThis paper presents the internet-based remote control of mobile robot. To face unpredictable Internet delays and possible connection rupture, a direct teleoperation architecture with “Speed Limit Module” (SLM) and “Delay Approximator” (DA) is proposed. This direct control architecture guarantees the path error of the robot motion is restricted within the path error tolerance of the application. Experiment results show the effectiveness and applicability of this direct internet control architecture in the real internet environment
Modular Approach for Expert System toward Anomaly: N-Layers
International audience—Smart cities and smart homes are booming fields of development of pervasive systems. With the high stakes these systems have to manage, and their sheer complexity, anomalies have to be considered. In these complex systems are many connected components with computing capacities. They can manage anomalies, even if partially, and can act as some kind of expert systems. These expert systems can be relied upon to provide anomaly management. The complexity to manage generic expert systems brings us to suggest another approach. In this paper, the N-layers is discussed. It layers the various existing expert systems to organize them as a more generic expert system. It also aims to correct some difficulties to develop and integrate generic expert systems into various scales complex systems, such as smart cities or smart homes
Characterization of recombinant human lactoferrin N-glycans expressed in the milk of transgenic cows.
Lactoferrin (LF) is one of the most abundant bioactive glycoproteins in human milk. Glycans attached through N-glycosidic bonds may contribute to Lactoferrin functional activities. In contrast, LF is present in trace amounts in bovine milk. Efforts to increase LF concentration in bovine milk led to alternative approaches using transgenic cows to express human lactoferrin (hLF). This study investigated and compared N-glycans in recombinant human lactoferrin (rhLF), bovine lactoferrin (bLF) and human lactoferrin by Nano-LC-Chip-Q-TOF Mass Spectrometry. The results revealed a high diversity of N-glycan structures, including fucosylated and sialylated complex glycans that may contribute additional bioactivities. rhLF, bLF and hLF had 23, 27 and 18 N-glycans respectively with 8 N-glycan in common overall. rhLF shared 16 N-glycan with bLF and 9 N-glycan with hLF while bLF shared 10 N-glycan with hLF. Based on the relative abundances of N-glycan types, rhLF and hLF appeared to contain mostly neutral complex/hybrid N-glycans (81% and 52% of the total respectively) whereas bLF was characterized by high mannose glycans (65%). Interestingly, the majority of hLF N-glycans were fucosylated (88%), whereas bLF and rhLF had only 9% and 20% fucosylation, respectively. Overall, this study suggests that rhLF N-glycans share more similarities to bLF than hLF
A Framework for Anomaly Diagnosis in Smart Homes Based on Ontology
International audienceSmart homes are pervasive environments to enhance the comfort, the security, the safety and the energy consumption of the residence. An ambient intelligence system uses information of devices to represent the context of the home and its residents. Based on a context database, this system infer the daily life activities of the resident. Hence, abnormal behavior or chronic disease can be detected by the system. Due to the complexity of these systems, a large variety of anomalies may occur and disrupt the functioning of critical and essential applications. To detect anomalies and take appropriate measures, an anomaly management system has to be integrated in the overall architecture. In this paper, we propose an anomaly management framework for smart homes. This framework eases the work of designers in the conception of anomaly detection modules and processes to respond to an anomaly appropriately. Our framework can be used in all heterogeneous environments such as smart home because it uses Semantic Web ontologies to represent anomaly information. Our framework can be useful to detect hardware, software, network, operator and context faults. To test the efficiency of our anomaly management framework, we integrate it in the universAAL middleware. Based on a reasoner, our framework can easily infer some context anomalies and take appropriate measures to restore the system in a full functioning state
αS1-casein, which is essential for efficient ER-to-Golgi casein transport, is also present in a tightly membrane-associated form
<p>Abstract</p> <p>Background</p> <p>Caseins, the main milk proteins, aggregate in the secretory pathway of mammary epithelial cells into large supramolecular structures, casein micelles. The role of individual caseins in this process and the mesostructure of the casein micelle are poorly known.</p> <p>Results</p> <p>In this study, we investigate primary steps of casein micelle formation in rough endoplasmic reticulum-derived vesicles prepared from rat or goat mammary tissues. The majority of both α<sub>S1</sub>- and β-casein which are cysteine-containing casein was dimeric in the endoplasmic reticulum. Saponin permeabilisation of microsomal membranes in physico-chemical conditions believed to conserve casein interactions demonstrated that rat immature β-casein is weakly aggregated in the endoplasmic reticulum. In striking contrast, a large proportion of immature α<sub>S1</sub>-casein was recovered in permeabilised microsomes when incubated in conservative conditions. Furthermore, a substantial amount of α<sub>S1</sub>-casein remained associated with microsomal or post-ER membranes after saponin permeabilisation in non-conservative conditions or carbonate extraction at pH11, all in the presence of DTT. Finally, we show that protein dimerisation via disulfide bond is involved in the interaction of α<sub>S1</sub>-casein with membranes.</p> <p>Conclusions</p> <p>These experiments reveal for the first time the existence of a membrane-associated form of α<sub>S1</sub>-casein in the endoplasmic reticulum and in more distal compartments of the secretory pathway of mammary epithelial cells. Our data suggest that α<sub>S1</sub>-casein, which is required for efficient export of the other caseins from the endoplasmic reticulum, plays a key role in early steps of casein micelle biogenesis and casein transport in the secretory pathway.</p
Dynamic sound attenuation at hypersonic frequencies in silica glass
In order to clarify the origin of the dominant processes responsible for the
acoustic attenuation of phonons, which is a much debatted topic, we present
Bril louin scattering experiments in various silica glasses of different OH
impurities content. A large temperature range, from 5 to 1500 K is
investigated, up to the glass transition temperature. Comparison of the
hypersonic wave attenuation in various samples allows to identify two different
processes. The first one induce s a low temperature peak related to
relaxational processes; it is strongly sensitive to the extrinsic defects. The
second, dominant in the hig h temperature range, is weakly dependent on the
impurities and can be ascribed to anharmonic interactions
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