Efficient peptide mapping and its application to identify embryo proteins in rice proteome analysis

Using direct N-terminal analysis, only 31 N-terminally unblocked proteins out of 100 rice embryo proteins could be identified. To obtain protein sequence information for the remaining 69 blocked proteins, we developed a simple, efficient and rapid method. Using this method, we determined the peptide maps of 20 proteins per day in 10 pmol amounts. Applying this method to rice proteome analysis, we determined the internal sequences of all 69 blocked proteins. A total of 28 proteins out of 100 analyzed showed sequence similarity to the proteins with known functions in the SWISS-PROT and NCBI databases. Alternatively, we also used peptide mass fingerprinting determined by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) to identify the rice proteins separated by two-dimensional electrophoresis (2-DE). Although peptide-mass fingerprinting is a high-throughput method, we could not easily identify all the rice proteins or genes by this method, because the complete database information on rice, is not yet available and many proteins are post-translationally modified. Therefore, at present, the improved peptide mapping method as we report here is considered to be very useful in rice proteome analysis, especially for blocked proteins.     

14N@C60 formation in a nitrogen rf-plasma

Atomic nitrogen was encapsulated inside a vaporized C60 molecule in rf-plasma, which was confirmed by ESR.     

Tetrasilatetrahedranide: a silicon cage anion

The first silicon cage anion, tris{bis[bis(trimethylsilyl)methyl](methyl)silyl}tetrasilatetrahedranide (6-), has been synthesized by the reaction of tetrakis{bis[bis(trimethylsilylmethyl](methyl)silyl}tetrasilatetrahedrane with potassium graphite in diethyl ether by reductive cleavage of exocyclic Si-Si bond. The structural characterization of K+(18-crown-6).6- has been achieved by X-ray crystallography, showing that 6- is a separated ion pair and the tetrasilatetrahedranide moiety has a significantly distorted tetrahedrane skeleton containing one inverted tetrahedral (umbrella type) silicon atom. The four silicon atoms in the Si4 skeleton are equivalent on the NMR time scale due to the migration of the Dis2MeSi substituent.     

Information Inequalities in a Family of Uniform Distributions

For a family of uniform distributions, it is shown that for any small < 0 the average mean squared error (MSE) of any estimator in the interval of values of length and centered at ₀ can not be smaller than that of the midrange up to the order o(n ^–2) as the size n of sample tends to infinity. The asymptotic lower bound for the average MSE is also shown to be sharp.     

The lower bound for the variance of unbiased estimators for one-directional family of distributions

Summary In this paper we introduce the concept of one-directionality which includes both cases of location (and scale) parameter and selection parameter and also other cases, and establish some theorems for shapr lower bounds and for the existence of zero variance unbiased estimator for this class of non-regular distributions.     

The structure and dynamics of 1,3,5-cycloheptatriene and 1,3-cycloheptadiene radical cations in low-temperature matrices. An ESR investigation

ESR spectra of the radical species derived from ⁶⁰Co γ-ray irradiation of 1,3,5-cycloheptatriene (1,3,5-CYT) and 1,3-cycloheptadiene (1,3-CYD) in halocarbon matrices have been studied in the temperature range 70–103 K. Ring inversion across the molecular plane occurs in the radical cation 1,3,5-CYT^+√ in CCl₃CF₃, the activation energy being 1.7 kcal/mol. Above 90 K, 1,3,5-CYT^+√ is deprotonated thermally in CCl₂FCClF₂. No dynamical effect has been observed for 1,3-CYD^+√.     

An application of generalized implicit function theorem to Goursat problems for nonlinear Leray-Volevich systems

Recently, Bramson proved a theorem that classifies the initial data under which solutions of the K-P-P equation converge to the appropriate travelling waves. In this paper, a simplified proof is given by using maximal principles instead of his Brownian motion approach. The regularity condition on the forcing term is also weakened.     

The 3/2th and 2nd order asymptotic efficiency of maximum probability estimators in non-regular cases

In this paper we consider the estimation problem on independent and identically distributed observations from a location parameter family generated by a density which is positive and symmetric on a finite interval, with a jump and a nonnegative right differential coefficient at the left endpoit. It is shown that the maximum probability estimator (MPE) is 3/2th order two-sided asymptotically efficient at a point in the sense that it has the most concentration probability around the true parameter at the point in the class of 3/2th order asymptotically median unbiased (AMU) estimators only when the right differential coefficient vanishes at the left endpoint. The second order upper bound for the concentration probability of second order AMU estimators is also given. Further, it is shown that the MPE is second order two-sided asymptotically efficient at a point in the above case only.Research supported by University of Tsukuba Project Research.     

Welding characteristics of 27, 40 and 67 kHz ultrasonic plastic welding systems using fundamental- and higher-resonance frequencies

The welding characteristics of 27, 40 and 67 kHz ultrasonic plastic welding systems that are driven at only the fundamental-resonance frequency vibration were compared, and also those of the welding systems that were driven at the fundamental and several higher resonance frequencies simultaneously were studied. At high frequency, welding characteristics can be improved due to the larger vibration loss of plastic materials. For welding of rather thin or small specimens, as the fundamental frequency of these welding systems is higher and the numbers of driven higher frequencies are driven simultaneously, larger welded area and weld strength were obtained.