Direct observation of a hydrophobic bond in loop-closure of a capped (-OCH2CH2-)n oligomer in water

The small r variation of the probability density P(r) for end-to-end separations of a -CH2CH3 capped (-OCH2CH2-)n oligomer in water is computed to be closely similar to the CH4 ... CH4 potential of mean force under the same circumstances. Since the aqueous solution CH4 ... CH4 potential of mean force is the natural physical definition of a primitive hydrophobic bond, the present result identifies an experimentally accessible circumstance for direct observation of a hydrophobic bond which has not been observed previously because of the low solubility of CH4 in water. The physical picture is that the soluble chain molecule carries the capping groups into aqueous solution, and permits them to find one another with reasonable frequency. Comparison with the corresponding results without the solvent shows that hydration of the solute oxygen atoms swells the chain molecule globule. This supports the view that the chain molecule globule might have a secondary effect on the hydrophobic interaction which is of first interest here. The volume of the chain molecule globule is important for comparing the probabilities with and without solvent because it characterizes the local concentration of capping groups. Study of other capping groups to enable X-ray and neutron diffraction measurements of P(r) is discussed.Comment: 4 pages, 3 figure

Exact Phase Solutions of Nonlinear Oscillators on Two-dimensional Lattice

We present various exact solutions of a discrete complex Ginzburg-Landau (CGL) equation on a plane lattice, which describe target patterns and spiral patterns and derive their stability criteria. We also obtain similar solutions to a system of van der Pol's oscillators.Comment: Latex 11 pages, 17 eps file

Lithium Diffusion & Magnetism in Battery Cathode Material LixNi1/3Co1/3Mn1/3O2

We have studied low-temperature magnetic properties as well as high-temperature lithium ion diffusion in the battery cathode materials LixNi1/3Co1/3Mn1/3O2 by the use of muon spin rotation/relaxation. Our data reveal that the samples enter into a 2D spin-glass state below TSG=12 K. We further show that lithium diffusion channels become active for T>Tdiff=125 K where the Li-ion hopping-rate [nu(T)] starts to increase exponentially. Further, nu(T) is found to fit very well to an Arrhenius type equation and the activation energy for the diffusion process is extracted as Ea=100 meV.Comment: Submitted to Journal of Physics: Conference Series (2014

Turbulence near cyclic fold bifurcations in birhythmic media

We show that at the onset of a cyclic fold bifurcation, a birhythmic medium composed of glycolytic oscillators displays turbulent dynamics. By computing the largest Lyapunov exponent, the spatial correlation function, and the average transient lifetime, we classify it as a weak turbulence with transient nature. Virtual heterogeneities generating unstable fast oscillations are the mechanism of the transient turbulence. In the presence of wavenumber instability, unstable oscillations can be reinjected leading to stationary turbulence. We also find similar turbulence in a cell cycle model. These findings suggest that weak turbulence may be universal in biochemical birhythmic media exhibiting cyclic fold bifurcations.Comment: 14 pages 10 figure

Magnetic Ordering in V-Layers of the Superconducting System of Sr2VFeAsO3

Results of transport, magnetic, thermal, and 75As-NMR measurements are presented for superconducting Sr2VFeAsO3 with an alternating stack of FeAs and perovskite-like block layers. Although apparent anomalies in magnetic and thermal properties have been observed at ~150 K, no anomaly in transport behaviors has been observed at around the same temperature. These results indicate that V ions in the Sr2VO3-block layers have localized magnetic moments and that V-electrons do not contribute to the Fermi surface. The electronic characteristics of Sr2VFeAsO3 are considered to be common to those of other superconducting systems with Fe-pnictogen layers.Comment: 4 pages, 4 figures, To appear in JPSJ 79 (2010) 12371

An evaluation of a refresher training intervention for HIV lay counsellors in Chongwe District, Zambia

To address a severe shortage of human resources for health, the Zambian Ministry of Health has begun to make use of lay counsellors for HIV counselling and testing. However, their skills and knowledge rarely have been reviewed or refreshed. We conducted a two-day refresher workshop for lay counsellors to review their performance and refresh their skills and knowledge. The objective of this study was to evaluate the refresher training intervention for HIV lay counsellors in the rural district of Chongwe in Zambia. The two-day refreshertraining workshop was held in November 2009. Twenty-five lay counsellors were selected by District Health Office and participated in the workshop. The workshop included: the opening, a pre-training exercise, lectures on quality assurance with regard to testing and safety precautions, lectures on counselling, filling the gap/Q&A session, and a post-training exercise. In both the pre- and post-trainingexercise, participants answered 25 true/false questions and tested 10 blood panel samples to demonstrate their knowledge and skill on HIV counselling and testing. The average overall knowledge test score  increased from 79% to 95% (p<0.001). At the baseline, knowledgetest scores in topic of standard precaution and post-exposure prophylaxis were relatively low (58%) but rose to 95% after the training (p<0.001). The per cent agreement of HIV testing by lay counsellors with reference laboratory was 99.2%. Participants’ knowledge was improved during the workshop and skill at HIV testing was found to remain at a high level of accuracy. Relatively weak knowledge of standard precautions and post-exposure prophylaxis suggests that lay counsellors are at risk of nosocomial infections, particularly in the absence of refresher training interventions. We conclude that the refresher training was effective for improving the knowledge and skills of lay counsellors and provided an opportunity to monitor their performance

Renormalization Group Theory for a Perturbed KdV Equation

We show that renormalization group(RG) theory can be used to give an analytic description of the evolution of a perturbed KdV equation. The equations describing the deformation of its shape as the effect of perturbation are RG equations. The RG approach may be simpler than inverse scattering theory(IST) and another approaches, because it dose not rely on any knowledge of IST and it is very concise and easy to understand. To the best of our knowledge, this is the first time that RG has been used in this way for the perturbed soliton dynamics.Comment: 4 pages, no figure, revte

Near-infrared spectroscopy and plasma homovanillic acid levels in bipolar disorder: a case report

Misdiagnosis of bipolar disorder is a serious, but not unusual problem for patients. Nevertheless, there are few biomarkers for distinguishing unipolar and bipolar disorder. Near-infrared spectroscopy (NIRS) is a noninvasive and useful method for the measurement of hemoglobin concentration changes in the cortical surface area, which enables the assessment of brain function. We measured NIRS and plasma monoamine metabolite levels in a patient with bipolar disorder. A 22-year-old man was admitted due to major depression. At admission, NIRS findings showed oxygenated hemoglobin reincrease in the posttask period, which is characteristic of schizophrenia. After treatment with paroxetine, he became manic with psychotic symptoms. His plasma level of homovanillic acid just before the manic switch was ten times higher than that just after paroxetine initiation. Treatment with lithium and antipsychotics was successful, and plasma homovanillic acid decreased after treatment. In this case, the NIRS findings may predict a possible risk of a manic switch, which is likely induced by paroxetine. NIRS may be able to help distinguish unipolar and bipolar disorder in clinical settings