578 research outputs found

    Chaotic Attractor Hopping yields Logic Operations

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    Certain nonlinear systems can switch between dynamical attractors occupying different regions of phase space, under variation of parameters or initial states. In this work we exploit this feature to obtain reliable logic operations. With logic output 0 or 1 mapped to dynamical attractors bounded in distinct regions of phase space, and logic inputs encoded by a very small bias parameter, we explicitly demonstrate that the system hops consistently in response to an external input stream, operating effectively as a reliable logic gate. This system offers the advantage that very low-amplitude inputs yield highly amplified outputs. Additionally, different dynamical variables in the system yield complementary logic operations in parallel. Further, we show that in certain parameter regions noise aids the reliability of logic operations, and is actually necessary for obtaining consistent outputs. This leads us to a generalization of the concept of Logical Stochastic Resonance to attractors more complex than fixed point states, such as periodic or chaotic attractors. Lastly, the results are verified in electronic circuit experiments, demonstrating the robustness of the phenomena. So we have combined the research directions of Chaos Computing and Logical Stochastic Resonance here, and this approach has the potential to be realized in wide-ranging systems

    Activation of phospholipase A2 by Hsp70 in vitro

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    Corrigendum to “Activation of phospholipase A2 by Hsp70 in vitro” Biochimica et Biophysica Acta (BBA) – Biomembranes Vol. 1838, Issue 7, July 2014, Pages 1921 10.1016/j.bbamem.2014.03.020Peer reviewe

    Serum n-6 polyunsaturated fatty acids and risk of atrial fibrillation : the Kuopio Ischaemic Heart Disease Risk Factor Study

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    Purpose N-6 polyunsaturated fatty acids (PUFA), particularly linoleic acid (LA), have been associated with lower risk of coronary heart disease (CHD), but little is known about their antiarrhythmic properties. We investigated the association of the serum n-6 PUFAs with the risk of atrial fibrillation (AF), the most common type of cardiac arrhythmia. Methods The study included 2450 men from the Kuopio Ischaemic Heart Disease Risk Factor Study, aged 42-60 years at baseline. The total n-6 PUFA includes linoleic acid (LA), arachidonic acid (AA), gamma-linolenic acid (GLA) and dihomo-gamma-linolenic acid (DGLA). Cox proportional hazards regression was used to estimate hazard ratio (HR) of incident events. Results During the mean follow-up of 22.4 years, 486 AF cases occurred. The multivariable-adjusted HR in the highest versus the lowest quartile of total serum n-6 PUFA concentration was 0.79 (95% CI 0.58-1.08, P trend = 0.04). When evaluated individually, only serum LA concentration was inversely associated with AF risk (multivariable-adjusted extreme-quartile HR 0.69, 95% CI 0.51-0.94, P trend = 0.02). These associations were stronger among the men without history of CHD or congestive heart failure at baseline, compared to men with such disease history (P for interaction = 0.05 for total n-6 PUFA and LA). Similar associations were observed with dietary LA and AA intakes. No significant associations were observed with serum AA, GLA or DGLA concentrations. Conclusions Higher circulating concentration and dietary intake of n-6 PUFA, mainly LA, are associated with lower risk of AF, especially among men without history of CHD or congestive heart failure.Peer reviewe

    Stress variations effect on the accuracy of slitting method for measuring residual stresses

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    To maintain the structural integrity of the engineering components, having an exact knowledge of residual stresses is important. Among all mechanical strain relief techniques to measure residual stresses, slitting is one of the youngest. This technique relies on the introduction of a narrow slot of increasing depth in a part containing residual stresses. Similar to other measurement techniques, slitting also employs simplifying assumptions. One of these assumptions is that the stress does not vary along the cut line. There are many sources of errors in the slitting method. However, the error caused by this assumption can be severe. In this research, residual stresses of quenched samples were measured experimentally using slitting technique. The results were then compared with those obtained from the finite element analyses. The cylindrical specimens were designed with different ratio of height to diameter to investigate the effect of stress variations in transverse direction along the cut plane. It was evident that the non-uniformity of stress can severely influence the residual stresses measurement. The experimental results confirmed the numerical findings

    Associations of the serum n-6 PUFA with exercise cardiac power in men

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    Low intake or tissue concentrations of the n-6 PUFA, especially to the major n-6 PUFA linoleic acid (LA), and low exercise cardiac power (ECP) are both associated with CVD risk. However, associations of the n-6 PUFA with ECP are unknown. The aim of the present study was to explore cross-sectional associations of the serum total n-6 PUFA, LA, arachidonic acid (AA), gamma-linolenic acid (GLA) and dihomo-gamma-linolenic acid (DGLA) concentrations with ECP and its components. In total, 1685 men aged 42-60 years from the Kuopio Ischaemic Heart Disease Risk Factor Study and free of CVD were included. ANCOVA was used to examine the mean values of ECP (maximal oxygen uptake (VO2max)/maximal systolic blood pressure (SBP)) and its components in quartiles of the serum total and individual n-6 PUFA concentrations. After multivariable adjustments, higher serum total n-6 PUFA concentration was associated with higher ECP and VO2max (for ECP, the extreme-quartile difference was 0 center dot 77 ml/mmHg (95 % CI 0 center dot 38, 1 center dot 16, P (for trend) across quartiles < 0 center dot 001) and for VO2max 157 ml/min (95 % CI 85, 230, P (for trend) < 0 center dot 001), but not with maximal SBP. Similar associations were observed with serum LA concentration. Higher serum AA concentration was associated with higher ECP but not with VO2max or maximal SBP. The minor serum n-6 PUFA GLA and DGLA were associated with higher maximal SBP during exercise test and DGLA also with higher VO2max but neither with ECP. In conclusion, especially LA concentration was associated with higher ECP. This may provide one mechanism for the cardioprotective properties of, especially, LA.Peer reviewe

    Large scale structure around a z=2.1 cluster

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    The most prodigious starburst galaxies are absent in massive galaxy clusters today, but their connection with large scale environments is less clear at z2z\gtrsim2. We present a search of large scale structure around a galaxy cluster core at z=2.095z=2.095 using a set of spectroscopically confirmed galaxies. We find that both color-selected star-forming galaxies (SFGs) and dusty star-forming galaxies (DSFGs) show significant overdensities around the z=2.095z=2.095 cluster. A total of 8 DSFGs (including 3 X-ray luminous active galactic nuclei, AGNs) and 34 SFGs are found within a 10 arcmin radius (corresponds to \sim15 cMpc at z2.1z\sim2.1) from the cluster center and within a redshift range of Δz=0.02\Delta z=0.02, which leads to galaxy overdensities of δDSFG12.3\delta_{\rm DSFG}\sim12.3 and δSFG2.8\delta_{\rm SFG}\sim2.8. The cluster core and the extended DSFG- and SFG-rich structure together demonstrate an active cluster formation phase, in which the cluster is accreting a significant amount of material from large scale structure while the more mature core may begin to virialize. Our finding of this DSFG-rich structure, along with a number of other protoclusters with excess DSFGs and AGNs found to date, suggest that the overdensities of these rare sources indeed trace significant mass overdensities. However, it remains puzzling how these intense star formers are triggered concurrently. Although an increased probability of galaxy interactions and/or enhanced gas supply can trigger the excess of DSFGs, our stacking analysis based on 850 μ\mum images and morphological analysis based on rest-frame optical imaging do not show such enhancements of merger fraction and gas content in this structure.Comment: 11 pages, 4 figures, ApJ accepte

    "Dirty coagulation" technique as an alternative to microclips for control of bleeding from deep feeders during brain arteriovenous malformation surgery

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    Meticulous haemostasis is one of the most important factors during microneurosurgical resection of brain arteriovenous malformation (AVM). Controlling major arterial feeders and draining veins with clips and bipolar coagulation are well-established techniques, while managing with bleeding from deep tiny vessels still proves to be challenging. This technical note describes a technique used by the senior author in AVM surgery for last 20 years in dealing with the issue highlighted. "Dirty coagulation" is a technique of bipolar coagulation of small feeders carried out together with a thin layer of brain tissue that surrounds these fragile vessels. The senior author uses this technique for achieving permanent haemostasis predominantly in large and/or deep-seated AVMs. To illustrate the efficacy of this technique, we retrospectively reviewed the outcome of Spetzler-Martin (SM) grade III-V AVMs resected by the senior author over the last 5 years (2010-2015). Thirty-five cases of AVM surgeries (14 SM grade III, 15 SM grade IV and 6 SM grade V) in this 5-year period were analysed. No postoperative intracranial haemorrhage was encountered as a result of bleeding from the deep feeders. Postoperative angiograms showed complete resection of all AVMs, except in two cases (SM grade V and grade III). "Dirty coagulation" provides an effective way to secure haemostasis from deep tiny feeders. This cost-effective method could be successfully used for achieving permanent haemostasis and thereby decreasing postoperative haemorrhage in AVM surgery.Peer reviewe

    Functionalized iron oxide nanoparticles for controlling the movement of immune cells

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    Immunotherapy is currently being investigated for the treatment of many diseases, including cancer. The ability to control the location of immune cells during or following activation would represent a powerful new technique for this field. Targeted magnetic delivery is emerging as a technique for controlling cell movement and localization. Here we show that this technique can be extended to microglia, the primary phagocytic immune cells in the central nervous system. The magnetized microglia were generated by loading the cells with iron oxide nanoparticles functionalized with CpG oligonucleotides, serving as a proof of principle that nanoparticles can be used to both deliver an immunostimulatory cargo to cells and to control the movement of the cells. The nanoparticle-oligonucleotide conjugates are efficiently internalized, non-toxic, and immunostimulatory. We demonstrate that the in vitro migration of the adherent, loaded microglia can be controlled by an external magnetic field and that magnetically-induced migration is non-cytotoxic. In order to capture video of this magnetically-induced migration of loaded cells, a novel 3D-printed “cell box” was designed to facilitate our imaging application. Analysis of cell movement velocities clearly demonstrate increased cell velocities toward the magnet. These studies represent the initial step towards our final goal of using nanoparticles to both activate immune cells and to control their trafficking within the diseased brain
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