Simple Floating Voltage-Controlled Memductor Emulator for Analog Applications

The topic of memristive circuits is a novel topic in circuit theory that has become of great importance due to its unique behavior which is useful in different applications. But since there is a lack of memristor samples, a memristor emulator is used instead of a solid state memristor. In this paper, a new simple floating voltage-controlled memductor emulator is introduced which is implemented using commercial off the shelf (COTS) realization. The mathematical modeling of the proposed circuit is derived to match the theoretical model. The proposed circuit is tested experimentally using different excitation signals such as sinusoidal, square, and triangular waves showing an excellent matching with previously reported simulations

Numerical solutions of the compressible 3-D boundary-layer equations for aerospace configurations with emphasis on LFC

The application of stability theory in Laminar Flow Control (LFC) research requires that density and velocity profiles be specified throughout the viscous flow field of interest. These profile values must be as numerically accurate as possible and free of any numerically induced oscillations. Guidelines for the present research project are presented: develop an efficient and accurate procedure for solving the 3-D boundary layer equation for aerospace configurations; develop an interface program to couple selected 3-D inviscid programs that span the subsonic to hypersonic Mach number range; and document and release software to the LFC community. The interface program was found to be a dependable approach for developing a user friendly procedure for generating the boundary-layer grid and transforming an inviscid solution from a relatively coarse grid to a sufficiently fine boundary-layer grid. The boundary-layer program was shown to be fourth-order accurate in the direction normal to the wall boundary and second-order accurate in planes parallel to the boundary. The fourth-order accuracy allows accurate calculations with as few as one-fifth the number of grid points required for conventional second-order schemes

Dual mode nanoparticles: CdS coated iron nanoparticles

Reverse micelles can be used in a sequential fashion to make core-shell nanoparticles. Using this technique it is possible to make a magnetic quantum dot, by coating an iron core with a cadmium sulfide shell. Transmission electron microscopy indicated core-shell morphology and narrow size distribution of the obtained particles. Collectively, x-ray powder diffraction and x-ray photoelectron spectroscopy verified the presence of cadmium sulfide on the surface of the nanoparticles. Optical properties of the coated particles were demonstrated using fluorescence spectroscopy. A vibrating sample magnetometer was used to determine magnetic properties. Dual mode cadmium sulfide coatediron core-shell nanoparticles make unique candidates for the use in biomedical applications

Power Dissipation of Memristor-Based Relaxation Oscillators

Recently, many reactance-less memristive relaxation oscillators were introduced, where the charging and discharging processes depend on memristors. In this paper, we investigate the power dissipation in different memristor based relaxation oscillators. General expressions for these memristive circuits as well as the power dissipation formulas for three different topologies are derived analytically. In addition, general expressions for the maximum and minimum power dissipation are calculated. Finally, the calculated expressions are verified using PSPICE simulations showing very good matching

Inbreeding alters intersexual fitness correlations in Drosophila simulans.

PublishedJournal ArticleIntralocus sexual conflict results from sexually antagonistic selection on traits shared by the sexes. This can displace males and females from their respective fitness optima, and negative intersexual correlations (r mf) for fitness are the unequivocal indicator of this evolutionary conflict. It has recently been suggested that intersexual fitness correlations can vary depending on the segregating genetic variation present in a population, and one way to alter genetic variation and test this idea is via inbreeding. Here, we test whether intersexual correlations for fitness vary with inbreeding in Drosophila simulans isolines reared under homogenous conditions. We measured male and female fitness at different times following the establishment of isofemale lines and found that the sign of the association between the two measures varied with time after initial inbreeding. Our results are consistent with suggestions that the type of genetic variation segregating within a population can determine the extent of intralocus sexual conflict and also support the idea that sexually antagonistic alleles segregate for longer in populations than alleles with sexually concordant effects.Foundation for Polish Science (FNP)NER

Evolution of major histocompatibility complex class I and class II genes in the brown bear

International audienceBackground: Major histocompatibility complex (MHC) proteins constitute an essential component of the vertebrate immune response, and are coded by the most polymorphic of the vertebrate genes. Here, we investigated sequence variation and evolution of MHC class I and class II DRB, DQA and DQB genes in the brown bear Ursus arctos to characterise the level of polymorphism, estimate the strength of positive selection acting on them, and assess the extent of gene orthology and trans-species polymorphism in Ursidae . Results: We found 37 MHC class I, 16 MHC class II DRB, four DQB and two DQA alleles. We confirmed the expression of several loci: three MHC class I, two DRB, two DQB and one DQA. MHC class I also contained two clusters of non-expressed sequences. MHC class I and DRB allele frequencies differed between northern and southern populations of the Scandinavian brown bear. The rate of nonsynonymous substitutions (d N ) exceeded the rate of synonymous substitutions (d S ) at putative antigen binding sites of DRB and DQB loci and, marginally significantly, at MHC class I loci. Models of codon evolution supported positive selection at DRB and MHC class I loci. Both MHC class I and MHC class II sequences showed orthology to gene clusters found in the giant panda Ailuropoda melanoleuca. Conclusions: Historical positive selection has acted on MHC class I, class II DRB and DQB, but not on the DQA locus. The signal of historical positive selection on the DRB locus was particularly strong, which may be a general feature of caniforms. The presence of MHC class I pseudogenes may indicate faster gene turnover in this class through the birth-and-death process. South - north population structure at MHC loci probably reflects origin of the populations from separate glacial refugia

The effect of cross-contamination in the sequential interfacial polymerization on the RO performance of polyamide bilayer membranes

International audienceIn this study, hexafluoroalcohol-containing polyamide layer (HFAPA) was prepared on top of a conventional polyamide under-layer (REFPA) via sequential interfacial polymerization (SIP) to improve RO separation behavior, and the performance of the resulting bilayer membrane was thoroughly optimized by investigating the effect of cross-contamination in the SIP process. When several coupons of the polyamide bilayer membrane were prepared by SIP of MPD(aq), TMC(hx) and hexafluoroalcohol-containing diamine (HFAMDA)(aq) in the manner of subsequent membrane dipping, unreacted MPD monomer (mostly captured in the porous PSF support) carried over from the 1st interfacial reaction dissolved and accumulated in the 2nd aqueous solution as verified by UV spectroscopic analysis. The MPD contaminant then participated in the 2nd interfacial reaction, forming copolyamide with HFAMDA monomer onto the REFPA. Depending on the amount of MPD contaminant accumulated in the 2nd aqueous solution, the composition of the resulting co-polyamide in the top-layer varied, causing a significant variation of RO performance; the flux was gradually decreased with the increase of MPD contaminants while the salt rejection slightly increased (from 1st coupon toward 4th coupon). This result indicated that a trace amount of MPD contaminant may be necessary to maximize RO separation behavior. Through in-depth performance evaluation of polyamide bilayer membranes prepared by adding various known-amount of MPD into 2nd HFAMDA solution, and also by applying a frame process (2nd amine solution was applied only top surface of membrane) to eliminate uncontrollable MPD contamination, we have successfully demonstrated consistent RO performance, and identified an optimum material composition to provide superior separation performance. The bilayer membrane prepared by adding 1.2 mol% of MPD to the total amount of HFAMDA in the 2nd aqueous solution showed 99.8% NaCl rejection with the water flux of 45 LMH under the cross-flow filtration performed with 2000 ppm NaCl solution at 400 psi, 25 °C

Effect of recombinant human erythropoietin and doxorubicin in combination on the proliferation of MCF-7 and MDA-mb231 breast cancer cells

Patients with cancer often exhibit signs of anemia as the result of the disease. Thus, cancer chemotherapies often include erythropoietin (EPO) in the regime to improve the survival rate of these patients. The aim of the present study was to determine the effect of EPO on doxorubicin-treated breast cancer cells. The cytotoxicity of doxorubicin alone or in combination with EPO against the MCF-7 and MDA-MB 231 human breast cancer cells were determined using an MTT cell viability assay, neutral red (NR) uptake assay and lactate dehydrogenase (LDH) assay. The estimated half maximal inhibitory concentration values for doxorubicin and the combination of doxorubicin with EPO were between 0.140 and 0.260 µg/ml for all cells treated for 72 h. Treatment with doxorubicin in combination with EPO led to no notable difference in cytotoxicity, compared with treatment with doxorubicin alone. The antiproliferative effect of doxorubicin at a concentration of 1 µg/ml on the MDA MB 231 cells was demonstrated by the decrease in viable cells from 3.6x10(5) at 24 h to 2.1x10(5) at 72 h of treatment. In order to confirm apoptosis in the doxorubicin-treated cells, the activities of caspases-3/7 and 9 were determined using a TBE assay. The results indicated that the activities of caspases-3/7 and 9 were significantly elevated in the doxorubicin-treated MDA-MB-231 cells by 571 and 645%, respectively, and in the MCF 7 cells by 471 and 345%, respectively, compared with the control cells. EPO did not modify the effect of doxorubicin on these cell lines. The results of the present study suggested that EPO was safe for use in combination with doxorubicin in the treatment of patients with breast cancer and concurrent anemia

Probabilistic Reuse of Past Search Results

International audienceIn this paper, a new Monte Carlo algorithm to improve precision of information retrieval by using past search results is presented. Experiments were carried out to compare the proposed algorithm with traditional retrieval on a simulated dataset. In this dataset, documents, queries, and judgments of users were simulated. Exponential and Zipf distributions were used to build document collections. Uniform distribution was applied to build the queries. Zeta distribution was utilized to simulate the Bradford’s law representing the judgments of users. Empirical results show a better performance of our algorithm compared with traditional retrieval