Bogoliubov Hamiltonian as Derivative of Dirac Hamiltonian via Braid Relation

In this paper we discuss a new type of 4-dimensional representation of the braid group. The matrices of braid operations are constructed by q-deformation of Hamiltonians. One is the Dirac Hamiltonian for free electron with mass m, the other, which we find, is related to the Bogoliubov Hamiltonian for quasiparticles in $^3$He-B with the same free energy and mass being m/2. In the process, we choose the free q-deformation parameter as a special value in order to be consistent with the anyon description for fractional quantum Hall effect with $\nu = 1/2$.Comment: 3 pages, 5 figure

Novel pH control strategy for glutathione overproduction in batch cultivation of Candida utilis

The effects of pH values on cell growth and glutathione (GSH) production were studied in batch cultivation of Candida utilis. According to the fact that lower pH value favors cells growth but retards GSH production and higher pH value promotes GSH production while inhibits cells growth, a pH-shift strategy, optimized via simulating Gauss function, was developed. By applying two-stage pH-shift strategy of controlling pH at 5.0 for first 7.5 h and switching to 6.0 afterwards, final GSH yield and productivity reached 279 and 12.7 mg/l/h after 22 h cultivation, increased by 30 and 42%, respectively,compared to constant pH 5.5 operation. Moreover, by feeding glucose instead of sulphuric acid (H2SO4) solution to control pH, maximal GSH yield of 315 mg/l was achieved, suggesting application of pH-shift strategy for GSH overproduction as being feasible

Metabolic responses of alfalfa (Medicago Sativa L.) leaves to low and high temperature induced stresses

To explore adaptation mechanism of alfalfa to cold and heat stresses, status of sucrose metabolism and relative water content (RWC) in leaves under low and high temperature treatments were studied. Seedlings (35 day old) were transferred to chambers for treatments. First group was subjected to 5°C as low temperature (LT) stress, second group at 33°C as high temperature (HT) stress and third group at 25°C as the control (CK). Results indicated that, both stresses led to an increase in degree and duration of genes expression and corresponding enzymes activities of sucrose phosphate synthase (SPS) and sucrose synthase (SS), but LT showed a more significant effect. As a result, lower starch content and higher contents of soluble reducing sugar, fructose and sucrose were observed under LT stress. Moreover, LT stress lowered malondialdehyde (MDA) content and electrolyte leakage in leaves, thus achieving a higher RWC. It was suggested that, relatively higher RWC in leaves by LT stress resulted from lowered water potential, and transpiration can explain the reason that alfalfa plants are cold-tolerant but heat-sensitive.Key words: Alfalfa, temperature stress, sucrose, sucrose phosphate synthase (SPS), relative water content