Computational dynamics method for evaluating the mobility of charged biomolecules passing through the electrical potential field within the ion selective channel on an excitable membrane

A mathematical method is introduced to characterize the electrokinetic behavior (electrophoresis) of a biomolecular particle which passes through a specific channel pore on an excitable biological membrane. The basic approach was first proposed by Booth (1950). The system was described by an equation of continuity and an equation of motion in which the driving force involves the diffusion effect, the hydrostatic pressure, and the electrostatic potential. By assuming linear relations between the velocity and the applied electrical field, solutions for the potential, pressure, and velocity were given by a series expansion of the charges on the particle. To examine the influence of ions surrounding the particle and forming an ionic cloud, the Debye–Huckel parameter was introduced. As the thickness of the double layer around the particle increased, the potential, velocity, pressure, and viscosity were changed significantly. The maximum influence was obtained when the radius of the particle became equal to the thickness of the double layer. Although this theory is valid for a charged, spherical, nonconducting particle only, the method is available for evaluating the kinetic behavior of a biomolecule that passes through a channel pore on a cellular membrane.This work was presented, in part, at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

Axioms for Recursion in Call-by-Value

We propose an axiomatization of fixpoint operators in typed call-by-value programming languages, and give its justifications in two ways. First, it is shown to be sound and complete for the notion of uniform T-fixpoint operators of Simpson and Plotkin. Second, the axioms precisely account for Filinski's fixpoint operator derived from an iterator (infinite loop constructor) in the presence of first-class continuations, provided that we define the uniformity principle on such an iterator via a notion of effect-freeness (centrality). We then explain how these two results are related in terms of the underlying categorical structures.     

Program transformation system based on generalized partial computation

Generalized Partial Computation (GPC) is a program transformation method utilizing partial information about input data, abstract data types of auxiliary functions and the logical structure of a source program. GPC uses both an inference engine such as a theorem prover and a classical partial evaluator to optimize programs. Therefore, GPC is more powerful than classical partial evaluators but harder to implement and control. We have implemented an experimental GPC system called WSDFU (Waseda Simplify-Distribute-Fold-Unfold). This paper demonstrates the power of the program transformation system as well as its theorem prover and discusses some future works. Yoshihiko Futamura, Ph.D.: He is Professor of Department of Information and Computer Science and the director of the Institute for Software Production Technology (ISPT) of Waseda University. He received his BS in mathematics from Hokkaido University in 1965, MS in applied mathematics from Harvard University in 1972 and Ph.D. degree from Hokkaido University in 1985. He joined Hitachi Central Research Laboratory in 1965 and moved to Waseda University in 1991. He was a visiting professor of Uppsala University from 1985 to 1986 and a visiting scholar of Harvard University from 1988 to 1989. Automatic generation of computer programs and programming methodology are his main research fields. He is the inventor of the Futamura Projections in partial evaluation and ISO8631 PAD (Problem Analysis Diagram). Zenjiro Konishi: He is a visiting lecturer of Institute for Software Production Technology, Waseda University. He received his M. Sc. degree in mathematics from Waseda University in 1995. His research interests include automated theorem proving. He received JSSST Takahashi Award in 2001. He is a member of JSSST and IPSJ. Robert Glück, Ph.D., Habil.: He is an Associate Professor of Computer Science at the University of Copenhagen. He received his Ph.D. and Habilitation (venia docendi) from the Vienna University of Technology in 1991 and 1997. He was research assistant at the City University of New York and received twice the Erwin-Schrodinger-Fellowship of the Austrian Science Foundation (FWF). After being an Invited Fellow of the Japan Society for the Promotion of Science (JSPS), he is now funded by the PRESTO21 program for basic research of the Japan Science and Technology Corporation (JST) and located at Waseda University in Tokyo. His main research interests are advanced programming languages, theory and practice of program transformation, and metaprogramming.     

Self-assembly of a silica-surfactant nanocomposite in a porous alumina membrane

A mesoporous membrane composed of nanochannels with a uniform diameter has a potential use for precise size-exclusive separation of molecules. Here, we report a novel method to form a hybrid membrane composed of silica-surfactant nanocomposite and a porous alumina membrane, by which size-selective transport of molecules across the membrane becomes possible. The nanocomposite formed inside each columnar alumina pore was an assembly of surfactant-templated silica-nanochannels with a channel diameter of 3.4 nm; the channel direction being predominantly oriented along the wall of the columnar alumina pore. Molecules could be transported across the membrane including the silica-surfactant nanocomposite with a capability of nanometre-order size-exclusive separation. Our proposed membrane system has a potential use not only for separation science, but also catalysis and chip technologies.     

Novel gene assay by probe-regulated simultaneous separation using capillary electrophoresis (CE-PRESS)

A novel methodology, a probe-regulated simultaneous separation using capillary electrophoresis (CE-PRESS), was developed for simultaneous assay of multiple genes. The single-stranded (ss) DNA-polymer conjugate-probes were placed in a capillary, and then a mixture of target ssDNAs was injected. These ssDNAs were hybridized with corresponding complementary ssDNA-polymer conjugate-probes after charging the capillary. Two resulting double-stranded (ds) complexes of ssDNAs and ssDNA-polymer conjugate-probes were detected at different migration times. We found that the electrophoretic mobilities of two ssDNA-poly(acrylamide) conjugate-probes [-(5'-GCCACCAGC-3')m-AAm(n)- and -(5'-ACCTTCACT-3')p-AAm(q)-; AAm, acrylamide] obtained by copolymerizing 5'-methacryloyl-modified ssDNA and AAm were different, depending on their molar fraction of ssDNA, although the ssDNAs chain lengths were the same. Two ssDNAs (5'-GCTGGTGGC-3' and 5'-AGTGAAGGT-3') having the same chain length were successfully separated with our novel system, although the separation of these ssDNAs is impossible in conventional capillary electrophoresis systems.     

Profile structure of magnetic flux lines in type-II superconductor from a rectangular electron hologram

Profile magnetic configuration of a quantized flux line and flux-line lattice penetrating a type-II superconductor thin foil, niobium, was observed by electron holography and Lorentz microscopy using a 300 kV field-emission electron microscope. Each single flux line was distributed periodically as lattice structure in the mixed state just below its critical temperature of 8.5 K, while at low temperature of 5 K the flux lines were weakly bound as bundles. In order to observe the flux-line distribution over a wide area, discrete Fourier transform reconstruction in the holography was extended for a rectangular area without loss of information and data precision.     

Comparison of enteral nutrition with combined enteral and parenteral nutrition in post-pancreaticoduodenectomy patients: a pilot study

Background  

Many clinical studies have demonstrated that early postoperative enteral nutrition (EN) improved the postroperative course. Post-pancreaticoduodenectomy (PD), patients tend to suffer from postoperative nausea, abdominal distention, and diarrhoea, causing difficulty in the introduction of EN. In this pilot study, we investigated the appropriate nutritional mode post-pancreatic surgery.     

Detection of back-side pit on a ferrous plate by magnetic flux leakage method with analyzing magnetic field vector

We have developed a magnetic flux leakage (MFL) system using magnetic resistive (MR) sensors for detecting two dimensional magnetic field components, and an induction coil that generates low magnetic field strengths and extremely low frequencies. The signal at each scanned measurement point (i) was divided by the signal strength M_mes,i and phase α_i by a lock-in amplifier. Using the strength M_mes,i and phase α_i, we calculated the imaginary part of the signal using the common phase β. By optimization of the common phase β to the imaginary part, the analyzed scanning data curve was shown to be effective in estimating the size (depth and diameter) of back-side pits on a ferrous plate. Comparing the two dimensional magnetic field components of leakage, the imaginary part of the y-component parallel to the induced magnetic field was found to be suitable for detecting the back-side pits.     

Effects of polyglycerol esters of fatty acids and ethylene‐vinyl acetate co‐polymer on crystallization behavior of biodiesel

Biodiesel fuels (BDF) have many problems in the cold due to their crystallization properties. In particular, precipitation of large crystals of high‐melting fractions in BDF at low temperatures remarkably changes cold flow property of BDF and, thereby, it increases the values of cold filter plugging point. In this study, we evaluated polyglycerol esters of fatty acids (PGE) and ethylene‐vinyl acetate co‐polymer (EVA) as chemical additives to improve the cold flow property of palm oil‐based FAME (PFME). The results of solid fat content measurement indicate that the simultaneous addition of PGE and EVA showed synergistic effects on suppression of crystallization of PFME, however such effect was not observed when EVA was used alone. DSC thermograms indicated that the PGE additives not only decreased the crystallization temperature but also kinetically suppressed the crystal growth. Polarized light microscopy showed that the simultaneous addition of PGE and EVA led to the formation of considerably small and fine‐dispersed crystals of PFME. These results indicate that combined effects of PGE and EVA caused the formation of fine‐dispersed PFME crystals, which could improve the viscous properties of palm oil‐based BDF at relatively cold temperatures.     

Distractor devaluation effect in the attentional blink: Direct evidence for distractor inhibition.

When two targets (T1 and T2) are embedded in rapid serial visual presentation (RSVP), T2 is often missed (attentional blink, AB) if T2 follows T1 by less than 500 ms. Some have proposed that inhibition of a distractor following T1 contributes to the AB, but no direct evidence supports this proposal. This study examined distractor inhibition by assessing a distractor devaluation effect where inhibited items were evaluated less positively than controls. Experiments 1 and 2 showed that a distractor presented just after T1 was evaluated less favorably when T2 was misidentified, independently of stimulus characteristics. Experiment 3 produced distractor devaluation in T2 incorrect trials when the evaluated distractor was the second item after T1. In contrast, a distractor presented before T1 was not devaluated (Experiment 4). Experiment 5 demonstrated that participants could not recognize presented distractors after an RSVP task, rejecting the possibility that memorized distractors were devalued. Results show a relationship between the devaluation of distractors following T1 and the AB, providing the first direct evidence of the distractor inhibition during the AB. (PsycINFO Database Record (c) 2010 APA, all rights reserved)