S-matrices for spinor particles on Reissner-Nordstr\"{o}m black holes

The scattering problems arising when considering the contribution of the topologically inequivalent configurations of the spinors on Reissner-Nordstr\"{o}m black holes to the Hawking radiation are correctly stated. The corresponding $S$-matrices are described and presented in the form convenient to numerical computations.Comment: 11 pages, LaTe

Multi-neuronal refractory period adapts centrally generated behaviour to reward

Oscillating neuronal circuits, known as central pattern generators (CPGs), are responsible for generating rhythmic behaviours such as walking, breathing and chewing. The CPG model alone however does not account for the ability of animals to adapt their future behaviour to changes in the sensory environment that signal reward. Here, using multi-electrode array (MEA) recording in an established experimental model of centrally generated rhythmic behaviour we show that the feeding CPG of Lymnaea stagnalis is itself associated with another, and hitherto unidentified, oscillating neuronal population. This extra-CPG oscillator is characterised by high population-wide activity alternating with population-wide quiescence. During the quiescent periods the CPG is refractory to activation by food-associated stimuli. Furthermore, the duration of the refractory period predicts the timing of the next activation of the CPG, which may be minutes into the future. Rewarding food stimuli and dopamine accelerate the frequency of the extra-CPG oscillator and reduce the duration of its quiescent periods. These findings indicate that dopamine adapts future feeding behaviour to the availability of food by significantly reducing the refractory period of the brain's feeding circuitry

Self-Reduction Rate of a Microtubule

We formulate and study a quantum field theory of a microtubule, a basic element of living cells. Following the quantum theory of consciousness by Hameroff and Penrose, we let the system to reduce to one of the classical states without measurement if certain conditions are satisfied(self-reductions), and calculate the self-reduction time $\tau_N$ (the mean interval between two successive self-reductions) of a cluster consisting of more than $N$ neighboring tubulins (basic units composing a microtubule). $\tau_N$ is interpreted there as an instance of the stream of consciousness. We analyze the dependence of $\tau_N$ upon $N$ and the initial conditions, etc. For relatively large electron hopping amplitude, $\tau_N$ obeys a power law $\tau_N \sim N^b$, which can be explained by the percolation theory. For sufficiently small values of the electron hopping amplitude, $\tau_N$ obeys an exponential law, $\tau_N \sim \exp(c' N)$. By using this law, we estimate the condition for $\tau_N$ to take realistic values $\tau_N$ \raisebox{-0.5ex}{$\stackrel{>}{\sim}$} $10^{-1}$ sec as $N$ \raisebox{-0.5ex} {$\stackrel{>}{\sim}$} 1000.Comment: 7 pages, 9 figures, Extended versio

Lattice Distortion and Octupole Ordering Model in CexLa1-xB6

Possible order parameters of the phase IV in CexLa1-xB6 are discussed with special attention to the lattice distortion recently observed. A \Gamma_{5u}-type octupole order with finite wave number is proposed as the origin of the distortion along the [111] direction. The \Gamma_8 crystalline electric field (CEF) level splits into three levels by a mean field with the \Gamma_{5u} symmetry. The ground and highest singlets have the same quadrupole moment, while the intermediate doublet has an opposite sign. It is shown that any collinear order of \Gamma_{5u}-type octupole moment accompanies the \Gamma_{5g}-type ferro-quadrupole order, and the coupling of the quadrupole moment with the lattice induces the distortion. The cusp in the magnetization at the phase transition is reproduced, but the internal magnetic field due to the octupole moment is smaller than the observed one by an order of magnitude.Comment: 5 pages, 4 figures, submitted to J. Phys. Soc. Jp

Learning cover context-free grammars from structural data

We consider the problem of learning an unknown context-free grammar when the only knowledge available and of interest to the learner is about its structural descriptions with depth at most $\ell.$ The goal is to learn a cover context-free grammar (CCFG) with respect to $\ell$, that is, a CFG whose structural descriptions with depth at most $\ell$ agree with those of the unknown CFG. We propose an algorithm, called $LA^\ell$, that efficiently learns a CCFG using two types of queries: structural equivalence and structural membership. We show that $LA^\ell$ runs in time polynomial in the number of states of a minimal deterministic finite cover tree automaton (DCTA) with respect to $\ell$. This number is often much smaller than the number of states of a minimum deterministic finite tree automaton for the structural descriptions of the unknown grammar

Effect of additives on cordycepin production using a Cordyceps militaris mutant induced by ion beam irradiation

To obtain a sustainable mutant of the medicinal mushroom Cordyceps militaris with a higher cordycepin production, high-energy ion beam irradiation was applied in the present study. Upon successful irradiation by a proton beam, 30 classes of 8-azaadenine and 28 classes of 8-azaaguanine resistant mutants were obtained of which 7 classes (A63-7, A63-8, A81-2, A81-6, G63-8, G81-3, G82-4) were selected as initially promising mutants using their antibacterial ability as an index of cordycepin production. Among these mutants, G81-3 had the highest cordycepin production of 6.84 g/l using optimized conditions compared to that of the control of 2.45 g/l (2.79 times higher). In addition, to explore the influences of different additives on the cordycepin production usihg the above mutant in a surface liquid culture, adenosine and glycine were used as additives. In the culture medium under the previously optimized conditions for the said mutant, 2, 4, 6, 8 and 10 g/l adenosine were separately added. These results revealed the highest cordycepin production of 8.57 g/l when using 6.g/l adenosine was 28.10% higher than that of the control (6.69 g/l). This is a highest report of cordycepin production until now. Similarly, the results of other concentrations also superseded the control. The time course of glucose showed that the glucose consumption for the 4 g/l adenosine was the fastest, while that of 10 g/l was the slowest with the longest culture time among all the treatments. For the same purpose, glycine was used with yeast extr-act in weight percent ratios (yeast extract/glycine) of 40/60, 50/50, 60/40, 70/30, 80/20 and 90/10 under the condition that the total amount of glycine and yeast extract were fixed. Also, the glycine was separately added as 10, 20 and 30 weight percent of yeast extract in the culture medium having the same optimized conditions with a fixed yeast extract concentration. These results showed that the 90/10 ratio had the best cordycepin production of 6.80 g/l that was 12.40% higher versus the control (6.05 g/l). The cordycepin production of the 70/30 and 80/20 weight percent ratios were also higher than that of the control, while the others had a lower cordycepin production compared to that of the control; especially the cordycepin production with the 10, 20 and 30 weight percent yeast extracts inversely decreased in accordance with the used glycine concentration. Regarding the time course, the glucose consumption for the 40/60 weight percent ratio of yeast extract was the fastest, while that of the 30 weight percent was the slowest with the longest culture time among all the treatments. These results suggested that both the ion beam irrabdiation and additives had active influences on the cordycepin production and that adenosine had a much better influence than that of glycine. It was also evident that a higher concentration of both adenosine and glycine negatively affected the cordycepin production

Production of manganese peroxidase by white rot fungi from potato-processing wastewater: Role of amino acids on biosynthesis

The production of manganese peroxidase (MnP) by white rot fungus strain L-25 was carried out using potato-processing wastewater and the effects of amino acids in the potato-processing wastewater was investigated. The MnP was efficiently produced from the wastewater by the addition of glucose and the maximum MnP activity linearly increased with an increase in the glucose concentration. The initial pH affected the cell growth and also the production rate of the MnP. The maximum activity and theproduction rate of the MnP using the potato-processing wastewater-based medium were higher (ca. 2.5- fold) than that of the basal medium. Moreover, amino acids in the wastewater had significant effects onthe MnP production. L-Glutamic acid, L-aspartic acid and L-serine induced the MnP secretion, on the other hand, L-phenylalanine, L-tyrosine, L-leucine and L-lysine inhibited it. The addition of L-leucine and L-lysine caused growth inhibition, while, L-phenylalanine and L-tyrosine blocked the MnP biosynthetic pathway. Ammonium ion released from the L-phenylalanine by the L-phenylalanine ammonia-lyase participated in the repression of the MnP biosynthetic pathway of the strain L-25