Selective incorporation of docosahexaenoic acid into lysobisphosphatidic acid in cultured THP-1 macrophages

Lysobisphosphatidic acid (LBPA) is highly accumulated in specific domains of the late endosome and is involve in the biogenesis and function of this organelle. Little is known about the biosynthesis and metabolism of this lipid. We examined its FA composition and the incorporation of exogenous FA into LBPA in the human monocytic leukemia cell line THP-1. The LBPA FA composition in THP-1 cells exhibits an elevated amount of oleic acid (18∶1n−9) and enerichment of PUFA, especially DHA (22∶6n−3). DHA supplemented to the medium was efficiently incorporated into LBPA. In contrast, arachidonic acid (20∶4n−6) was hardly esterified to LBPA under the same experimental conditions. The turnover of DHA in LBPA was similar to that in other phospholipids. Specific incorporation of DHA into LBPA was also observed in baby hamster kidney fibroblasts, although LBPA in these cells contains very low endogenous levels of DHA in normal growth conditions. Our results, together with published observations, suggest that the specific incorporation of DHA into LBPA is a common phenomenon in mammalian cells. The physiological significance of DHA-enriched LBPA is discussed.     

A Model for Telephone Networks and Its Use for Routing Optimization Purposes

The problem studied here concerns the modeling of call blocking in telephone networks. From the usual assumptions such as exponential arrivals and holding time, lost call cleared, the state of the network is described by a finite Markov chain. From the transition probabilities of this process are derived the differential equations associated with the average occupancy of all trunk groups. These traffic equations are simplified by considering independence of blocking for trunk groups in series. The blocking probabilities are estimated using fictitious offered traffic and the Erlang B formula. Such representation takes into account peaky or smooth traffic characteristics. We develop this one-moment model for routing policies such as load sharing and overflow routing. Performances of the model are given in comparison to the solution of the exact Markov chain model or the results of Monte Carlo simulation. Finally, an application to routing optimization and network dimensioning is treated.     

A new model for the prediction of agricultural operator exposure during professional application of plant protection products in outdoor crops

A new predictive model for the estimation of agricultural operator exposure has been developed on the basis of new exposure data to improve the current agricultural operator exposure and risk assessment in the EU. The new operator exposure model represents current application techniques and practices in EU Member States (MS) and is applicable for national or zonal authorisation of plant protection products as well as for approval of active substances in plant protection products (PPP) supporting a stepwise risk assessment. 34 unpublished exposure studies conducted between 1994 and 2009 were evaluated for the new model. To ensure a very high quality of data the studies had to meet a set of quality criteria, e.g. GLP conformity or compliance with OECD guidance. Exposure data and supplementary information on the trials were used for a statistical analysis of exposure factors. The statistical analyses resulted in six validated models for typical outdoor scenarios of pesticide mixing/loading and application. As a major factor contributing to the exposure of operators, the amount of active substance used per day was identified. Other parameters such as formulation type, droplet size, presence of a cabin or density of the canopy were selected as factors for sub-scenarios. For two scenarios the corresponding datasets were too small to identify reliable exposure factors; instead the relevant percentiles of the exposure distribution were used. The whole project report on the development of the new model (including the underlying study data) and the corresponding exposure calculators will be published at the BfR website (http://www.bfr.bund.de) after confirmation of the model by EU MS.     

Inhibitory effect of oxygen on hydrogen‐induced fracture of A333 pipe steel

The effect of oxygen contained in hydrogen gas environment as an impurity on hydrogen environment embrittlement (HEE) of A333 pipe steel was studied through the fracture toughness tests in hydrogen gases. The oxygen contents in the hydrogen gases were 100, 10, and 0.1 vppm. A significant reduction in the J‐Δa curve was observed in the hydrogen with 0.1‐vppm oxygen. Under given loading conditions, the embrittling effect of hydrogen was completely inhibited by 100 vppm of oxygen. In the case of the hydrogen with 10‐vppm oxygen, initially the embrittling effect of hydrogen was fully inhibited, and then subsequently appeared. It was confirmed that 1‐vppm oxygen reduced the embrittling effect of hydrogen. The results can be explained by the predictive model of HEE proposed by Somerday et al.     

Removal of PCNB from aqueous solution by a fungal adsorption process

Removal of PCNB from aqueous solutions by fungal mycelia was studied. Adsorption of the fungicide by dead biomass of M. racemosus, R. arrhizus and S. cyanescens was determined and compared with sorption on isolated cell walls of these three strains. Biosorptive uptake capacities are described by Freundlich equations of the form Qe=Kf·Cnfe. Measured values of Kf and nf indicate significant differences in the curve shapes and sorption capacities between the three species. Better performances were revealed by M. racemosus and R. arrhizus. Sorption of PCNB by cell walls alone was lower and statistically different from sorption by heat-killed mycelia thus corroborating that biosorption involved both uptake by the cell walls and by other cellular components.     

核废料地质贮存介质黏土岩的三维各向异性热-水-力耦合数值模拟

为了解黏土岩在放射性废料长期贮存中的热-水-力耦合过程,结合MontTerri核废料贮存地下岩石试验工程中黏土岩各种物理量的各向异性特点,应用多孔介质力学耦合理论研究了该黏土岩在加热和冷却全过程中由于热荷载引起的耦合效应场。研究过程考虑温度升高引起的孔隙水黏滞性改变对渗透系数的影响。研究结果表明,岩体力学参数、水力学参数和热传导参数的各向异性特性是影响岩体的温度场、孔隙压力场和应力场分布的最主要因素。各向异性耦合模型与各向同性耦合模型的数值模拟对比研究结果表明：各向异性模型数值结果能更加客观地反映该地下岩石试验工程中黏土岩在受热状态下的热-水-力耦合效应;同时,也表明岩体在加热过程中一直处于受压状态,而在冷却过程中局部会出现拉应力,从而有可能导致拉裂缝的产生。     

RABL6A Regulates Schwann Cell Senescence in an RB1-Dependent Manner

Schwann cells are normally quiescent, myelinating glia cells of the peripheral nervous system. Their aberrant proliferation and transformation underlie the development of benign tumors (neurofibromas) as well as deadly malignant peripheral nerve sheath tumors (MPNSTs). We discovered a new driver of MPNSTs, an oncogenic GTPase named RABL6A, that functions in part by inhibiting the RB1 tumor suppressor. RB1 is a key mediator of cellular senescence, a permanent withdrawal from the cell cycle that protects against cell immortalization and transformation. Based on the RABL6A-RB1 link in MPNSTs, we explored the hypothesis that RABL6A promotes Schwann cell proliferation and abrogates their senescence by inhibiting RB1. Using sequentially passaged normal human Schwann cells (NHSCs), we found that the induction of replicative senescence was associated with reduced expression of endogenous RABL6A. Silencing RABL6A in low passage NHSCs caused premature stress-induced senescence, which was largely rescued by co-depletion of RB1. Consistent with those findings, Rabl6-deficient MEFs displayed impaired proliferation and accelerated senescence compared to wildtype MEFs. These results demonstrate that RABL6A is required for maintenance of proper Schwann cell proliferation and imply that aberrantly high RABL6A expression may facilitate malignant transformation.     

Workability Tests on Fresh Concrete Formulated with Eco-friendly Admixture

Extra-cellular compounds, secreted by microorganisms into their surroundings, can be integrated in concrete composition as admixtures. These substances are important in biofilm formation and some of them can be used as corrosion inhibitor of concrete reinforcement. This paper deals with products made with biological surface active compounds/agents allowing the development of more eco-friendly concrete. The influence of this environmentally friendly bio admixture on setting time, workability, bending and compressive strengths of various mortar based materials made of CEM I, CEM III and CEM V was studied. Mechanical tests were carried out to highlight the influence of admixture in workability and hardening of samples containing the biological product with ratio in the range of 0-2.5%. It was demonstrated that the presence of the new bio-compound admixture in mortar decreases their compressive strength after 28 days of standard curing, in spite of remaining higher than standard minimal strength. Furthermore, Vicat needle experiments have shown a tendency of this admixture to decrease the setting time. A discussion was finally proposed in order to correlate the setting times and the decrease of the mortar compressive strength, corresponding in fact to a hardening delay. This setting time delay could be linked to a delay of the admixtured mortar to increase its resistance. The slump results highlight the action of bio-admixture as a plasticizer on mortars because it increases their workability for a same water-cement ratio. This effect seems variable according to the added amount.     

Nouvelle méthode de détermination des parties réelles des paramétres électriques et magnétiques des résonateurs à ferrites saturés et non saturés

Real parts of dielectric and magnetic material parameters of saturated and partially magnetised ferrites are determined in the frequency range : 2.5-4 GHz. Formulas of the tensor permeability elements are not used for the calculation of these parameters which are deduced from the degenerated resonant requencies of theTM ₀₂₀ andTM _?210 modes. These frequencies are measured in an appropriate metallic cavity where is centered a ferrite disk suitable for a 2 GHz circulator.     

Morphology and chemistry of brown rat,Rattus norvegicus,preputial and clitoral glands

In contrast to previous results from laboratory rats, when sexual dimorphism occurred, clitoral glands from wild female rats were heavier and accounted for a greater proportion of body mass than preputial glands from wild males. Gland length and weight increased with body weight, but gland weight as a proportion of body weight did not. Preputial and clitoral glands showed seasonal differences in size: at one site glands were smaller in December than in April. Maturity, estrus, and pregnancy had no significant effect on clitoral gland size, but immature males had proportionally smaller preputial glands than mature males, and the absolute gland weight, but not gland weight as a proportion of body weight, increased with testes weight. There were no differences between the sexes in lipid production, which increased with preputial or clitoral gland weight. An homologous series of aliphatic acids and their methyl and ethyl esters, plus squalene, cholesterol and lanosterol, was revealed by GC-MS study of the trimethyl silyl derivatized lipid extract. Males and females could be distinguished by principal component analysis of chromatogram peaks.