The PennState/Toru\'n Center for Astronomy Search for Planets Around Evolved Stars. Basic parameters of a sample of evolved stars

The objective of the PSU/TCfA Search for Planets Around Evolved Stars is to study evolution of planetary systems in the stellar evolution timescale. For such an analysis precise physical parameters of the hosts of the planetary systems are essential. In this paper we present an attempt to obtain basic physical parameters for a sample of evolved stars observed within our survey with the High Resolution Spectrograph of the Hobby-Eberly Telescope.Comment: 2 pages, to appear in "Extreme Solar Systems", 2007 ASP Conference Series, eds. Debra Fischer, Fred Rasio, Steve Thorsett and Alex Wolszcza

Convergence analysis of SCCC and SCTCM with 'in-line' interleaver

This paper presents a technique for analyzing the performance of SCCC and SCTCM systems that use 'in-line' interleavers. This technique is a multidimensional extension of the well-known EXIT chart analysis, and enables us to optimize the constituent codes when in-line interleavers are used

Selective Stimulation of a Target Neuron in Micropatterned Neuronal Circuits Using a Pair of Needle Electrodes

Neurostimulation is an essential technique to trigger and modulate the spatiotemporal activity of local neuronal circuits. Current stimulation methods have a trade-off relationship among aiming precision, temporal resolution, and noninvasiveness, making it difficult to stimulate and monitor a single target neuron for a long term. Here, we show that a method using two needle electrodes in combination of micropatterning techniques provides new possibilities for targeting and stimulating a single neuron selectively. Results of physiological experiments as well as analog circuit simulation reveal that two needle electrodes can stimulate a target neuron selectively by placing the two needle electrodes in proximity to and to straddle the target neuron, and that the steepness of voltage applied to two needle electrodes is important for the target neuron to fire at a low voltage. The proposed method enables a noninvasive stimulation suitable for measuring long-term activity of local neuronal circuits

Flowering phenology and survival of two annual plants Impatiens noli-tangere and Persicaria thunbergii co-occurring in streamside environments

Flowering phenology of cleistogamous annual plants Impatiens noli-tangere and Persicaria thunbergii was studied with reference to their mortality in streamside environments in northern Japan. I. noli-tangere produced flower-buds and flowers from late June to October, whereas P. thunbergii did so from mid-August to October. Both species were often killed by rapid current and submergence after heavy rainfall, which was unpredictable in the timing and intensity. P. thunbergii was more tolerant to rapid current and submergence than I. noli-tangere. Some individuals of I. noli-tangere were killed by herbivory from sawfly larvae in summer, but P. thunbergii individuals were seldom killed by herbivory. In consequence, the percentage of individuals that survived until the end of September was higher in P. thunbergii than in I. noli-tangere. These situations are assumed to select a long reproductive life in I. noli-tangere and autumn flowering in P. thunbergii

Molecular cloning, expression and characterization of pyridoxamine–pyruvate aminotransferase

Pyridoxamine–pyruvate aminotransferase is a PLP (pyridoxal 5′-phosphate) (a coenzyme form of vitamin B(6))-independent aminotransferase which catalyses a reversible transamination reaction between pyridoxamine and pyruvate to form pyridoxal and L-alanine. The gene encoding the enzyme has been identified, cloned and overexpressed for the first time. The mlr6806 gene on the chromosome of a symbiotic nitrogen-fixing bacterium, Mesorhizobium loti, encoded the enzyme, which consists of 393 amino acid residues. The primary sequence was identical with those of archaeal aspartate aminotransferase and rat serine–pyruvate aminotransferase, which are PLP-dependent aminotransferases. The results of fold-type analysis and the consensus amino acid residues found around the active-site lysine residue identified in the present study showed that the enzyme could be classified into class V aminotransferases of fold type I or the AT IV subfamily of the α family of the PLP-dependent enzymes. Analyses of the absorption and CD spectra of the wild-type and point-mutated enzymes showed that Lys(197) was essential for the enzyme activity, and was the active-site lysine residue that corresponded to that found in the PLP-dependent aminotransferases, as had been suggested previously [Hodsdon, Kolb, Snell and Cole (1978) Biochem. J. 169, 429–432]. The K(d) value for pyridoxal determined by means of CD was 100-fold lower than the K(m) value for it, suggesting that Schiff base formation between pyridoxal and the active-site lysine residue is partially rate determining in the catalysis of pyridoxal. The active-site structure and evolutionary aspects of the enzyme are discussed