Solvable Potentials from Supersymmetric Quantum Mechanics

A recurrence relation of Riccati-type differential equations known in supersymmetric quantum mechanics is investigated to find exactly solvable potentials. Taking some simple {\it ans\"atze}, we find new classes of solvable potentials as well as reproducing the known shape-invariant ones.Comment: 14 pages, Late

Biotransformation of glycerol to 3-hydroxypropionaldehyde: Improved production by in situ complexation with bisulfite in a fed-batch mode and separation on anion exchanger.

3-Hydroxypropionaldehyde (3HPA) is an important C3 chemical that can be produced from renewable glycerol by resting whole cells of Lactobacillus reuteri. However the process efficiency is limited due to substrate inhibition, product-mediated loss of enzyme activity and cell viability, and also formation of by-products. Complex formation of 3HPA with sodium bisulfite and subsequent binding to Amberlite IRA-400 was investigated as a means of in situ product recovery and for overcoming inhibition. The adsorption capacity and -isotherm of the resin were evaluated using the Langmuir model. The resin exhibited maximum capacity of 2.92mmol complex/g when equilibrated with 45mL solution containing an equilibrium mixture of 2.74mmol 3HPA-bisulfite complex and 2.01mmol free 3HPA. The dynamic binding capacity based on the breakthrough curve of 3HPA and its complex on passing a solution with 2.49mmol complex and 1.65mmol free 3HPA was 2.01mmol/g resin. The bound 3HPA was desorbed from the resin using 0.20M NaCl with a high purity as a mixture of complexed- and free 3HPA at a ratio of 0.77mol/mol. Fed-batch biotransformation of glycerol (818.85mmol) with in situ 3HPA complexation and separation on the bisulfite-functionalized resin resulted in an improved process with consumption of 481.36mmol glycerol yielding 325.54mmol 3HPA at a rate of 17.13mmol/h and a yield of 68 mol%. Also, the cell activity was maintained for at least 28h

Flux analysis of the Lactobacillus reuteri propanediol-utilization pathway for production of 3-hydroxypropionaldehyde, 3-hydroxypropionic acid and 1,3-propanediol from glycerol

Background Lactobacillus reuteri converts glycerol to 3-hydroxypropionic acid (3HP) and 1,3-propanediol (1,3PDO) via 3-hydroxypropionaldehyde (3HPA) as an intermediate using enzymes encoded in its propanediol-utilization (pdu) operon. Since 3HP, 1,3PDO and 3HPA are important building blocks for the bio-based chemical industry, L. reuteri can be an attractive candidate for their production. However, little is known about the kinetics of glycerol utilization in the Pdu pathway in L. reuteri. In this study, the metabolic fluxes through the Pdu pathway were determined as a first step towards optimizing the production of 3HPA, and co-production of 3HP and 1,3PDO from glycerol. Resting cells of wild-type (DSM 20016) and recombinant (RPRB3007, with overexpressed pdu operon) strains were used as biocatalysts. Results The conversion rate of glycerol to 3HPA by the resting cells of L. reuteri was evaluated by in situ complexation of the aldehyde with carbohydrazide to avoid the aldehyde-mediated inactivation of glycerol dehydratase. Under operational conditions, the specific 3HPA production rate of the RPRB3007 strain was 1.9 times higher than that of the wild-type strain (1718.2 versus 889.0 mg/gCDW.h, respectively). Flux analysis of glycerol conversion to 1,3PDO and 3HP in the cells using multi-step variable-volume fed-batch operation showed that the maximum specific production rates of 3HP and 1,3PDO were 110.8 and 93.7 mg/gCDW.h, respectively, for the wild-type strain, and 179.2 and 151.4 mg/gCDW.h, respectively, for the RPRB3007 strain. The cumulative molar yield of the two compounds was ~1 mol/mol glycerol and their molar ratio was ~1 mol3HP/mol1,3PDO. A balance of redox equivalents between the glycerol oxidative and reductive pathway branches led to equimolar amounts of the two products. Conclusions Metabolic flux analysis was a useful approach for finding conditions for maximal conversion of glycerol to 3HPA, 3HP and 1,3PDO. Improved specific production rates were obtained with resting cells of the engineered RPRB3007 strain, highlighting the potential of metabolic engineering to render an industrially sound strain. This is the first report on the production of 3HP and 1,3PDO as sole products using the wild-type or mutant L. reuteri strains, and has laid ground for further work on improving the productivity of the biotransformation process using resting cells

The cortical activation pattern by a rehabilitation robotic hand: a functional NIRS study

Introduction: Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS), we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Methods: Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin (HbO), deoxy-hemoglobin (HbR) and total-hemoglobin (HbT) in five regions of interest: the primary sensory-motor cortex (SM1), hand somatotopy of the contralateral SM1, supplementary motor area (SMA), premotor cortex (PMC), and prefrontal cortex (PFC). Results: HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand (uncorrected, p < 0.01). By contrast, HbR value indicated significant activation only in the hand somatotopic area of the left SM1 (uncorrected, p < 0.01). Conclusions: Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation. © 2014 Chang, Lee, Gu, Lee, Jin, Yeo, Seo and Jang.1

Schwinger Pair Production at Finite Temperature in Scalar QED

In scalar QED we study the Schwinger pair production from an initial ensemble of charged bosons when an electric field is turned on for a finite period together with or without a constant magnetic field. The scalar QED Hamiltonian depends on time through the electric field, which causes the initial ensemble of bosons to evolve out of equilibrium. Using the Liouville-von Neumann method for the density operator and quantum states for each momentum mode, we calculate the Schwinger pair-production rate at finite temperature, which is the pair-production rate from the vacuum times a thermal factor of the Bose-Einstein distribution.Comment: RevTex 10 pages, no figure; replaced by the version accepted in Phys. Rev. D; references correcte

Analysis of the Relationship between Cerebellar Volume and Psychological Parameters in 20s Male Adults

AbstractThis study measured the cerebellar volume of normal male adults in 20s with magnetic resonance imaging (MRI) and analysed the relationship between cerebellar volume and various psychological parameters. The cerebellar volume of 58 males (mean age, 24.0-2.8 years) was measured using MRI. The Symptom Checklist-90-R (SCL-90-R) and the Component of Type A Behavior tests were performed. Using linear regression analysis, the relationship between cerebellar volume and psychological parameters was analysed. As phobic anxiety and ambition increased, cerebellar volume of normal male subjects in 20s decreased. This study showed that for even normal male adults, there exists a possible relationship between various psychological parameters and cerebellar volume

Prediction of Adult Emergence Time and Generation Number of Overwintered Small Brown Planthopper, Laodelphax striatellus According to RCP8.5 Climate Change Scenario

ABSTRACT: Recently, climate change scenarios were substituted by the Special Report on Emission Scenarios (SRES) for Representative Concentration Pathway (RCP). Using the RCP scenario, the World Meteorological Organization (WMO) produced new climate change scenarios. Further, the National Institute of Meteorological Research (NIMR) of Korea produced new climate change scenarios for the Korean Peninsula. In this study, emergence time of small brown planthopper (SBPH), Laodelphax striatellus and the number of generations a year were estimated during climatic normal year with previous studies and they were predicted during 2050s (2045-2054) and 2090s (2085-2094) by means of RCP8.5 climate change scenario. In comparison with 176.0±0.97 Julian data in the climatic normal year, the emergence time of overwintering SBPH was predicted to be 13.2±0.18 days (162.8±0.91 Julian date) earlier in 2050s and 32.1±0.61 days (143.9±1.08 Julian date) earlier in 2090s. The SBPH was expected to produce an additional 2.0±0.02 generations in 2050s and 5.2±0.06 generations in 2090s