Comparison among Various Expressions of Complex Admittance for Quantum System in Contact with Heat Reservoir

Relation among various expressions of the complex admittance for quantum systems in contact with heat reservoir is studied. Exact expressions of the complex admittance are derived in various types of formulations of equations of motion under contact with heat reservoir. Namely, the complex admittance is studied in the relaxation method and the external-field method. In the former method, the admittance is calculated using the Kubo formula for quantum systems in contact with heat reservoir in no external driving fields, while in the latter method the admittance is directly calculated from equations of motion with external driving terms. In each method, two types of equation of motions are considered, i.e., the time-convolution (TC) equation and time-convolutionless (TCL) equation. That is, the full of the four cases are studied. It is turned out that the expression of the complex admittance obtained by using the relaxation method with the TC equation exactly coincides with that obtained by using the external-field method with the TC equation, while other two methods give different forms. It is also explicitly demonstrated that all the expressions of the complex admittance coincide with each other in the lowest Born approximation for the systemreservoir interaction. The formulae necessary for the higher order expansions in powers of the system-reservoir interaction are derived, and also the expressions of the admittance in the n-th order approximation are given. To characterize the TC and TCL methods, we study the expressions of the admittances of two exactly solvable models. Each exact form of admittance is compared with the results of the two methods in the lowest Born approximation. It is found that depending on the model, either of TC and TCL would be the better method.Comment: 34pages, no figur

Detection of gfp expression from gfp-labelled bacteria spot inoculated onto sugarcane tissues

Green fluorescent protein (GFP) as a marker gene has facilitated biological research in plant-microbe interactions. However, there is one major limiting factor in the detection of GFP in living organisms whose cells emit background autofluorescence. In this study, Herbaspirillum sp. B501gfp1 bacterial cells were spot inoculated onto 5 month-old sterile micro-propagated sugarcane tissues to detect if the GFP fluorescence expression could be distinguished from the tissue’s background fluorescence. Stem tissues and leaf sections mounted on glass slides were directly inoculated with a single touch using the tip of a syringe previously dipped into the inoculum containing 108 bacterial cells/ml. We observed that GFP fluorescence could be easily distinguished in the stem than in the leaf tissues. However, the brightness level of the fluorescence varied with time as a result of fluctuations in the bacterial celldensity. The presence of chloroplasts in the leaf tissues of sugarcane requires the use of bright GFP variants when monitoring bacteria-plant interactions using GFP labelled bacteria

Paradoxical increase in the PPG amplitude

Background : Although an increase in sympathetic nerve activity is generally associated with a decrease in the photoplethysmography (PPG) amplitude, the present case study demonstrates that nociceptive stimuli, such as tracheal intubation, paradoxically induce an increase in PPG amplitude. To the best of our knowledge, this is the first study to capture an increase in the PPG amplitude in response to sympathetic nerve activation. Case presentation : A 73-year-old woman underwent open surgery. Following anesthesia induction, tracheal intubation was performed, which resulted in increased heart rate and raised blood pressure. While nociception usually decreases the PPG amplitude, the opposite was found. Conversely, the vascular stiffness K value, our research group’s unique monitoring method to quantify the strength of sympathetic activity, increased reflecting increased peripheral vascular resistance. Conclusions : We report a paradoxical case of increased PPG amplitude following tracheal intubation. It is important to note that the PPG amplitude does not always decrease with nociceptive stimuli

Colonization ability of Herbaspirillum spp. B501gfp1 in sugarcane, a non-host plant in the presence of indigenous diazotrophic endophytes

Inoculating sugarcane with a mixture of diazotrophic endophytic bacteria has shown that they can provide substantial amount of biologically fixed nitrogen to the plant. The genera of diazotrophic endophytes previously isolated from sugarcane have been reported associating with other nonleguminousplants showing a broad host range. This study examined the colonization ability of a wild rice isolate, Herbaspirillum spp., in sugarcane plants in the presence of indigenous endophytes using two inoculum concentrations (102 and 108 bacterial cells ml-1). Internal tissue colonization was observed in plants inoculated with both the 102 and 108 B501gfp1 bacterial cells ml-1 inoculum concentrations. However, extensive colonization and higher bacterial numbers were determined only in the basal stem tissues of plants inoculated with the 108 bacterial cells ml-1

Indication of antiferromagnetic interaction between paramagnetic Co ions in the diluted magnetic semiconductor Zn1−x_{1-x}Cox_{x}O

The magnetic properties of Zn$_{1-x}$Co$_x$O ($x=0.07$ and 0.10) thin films, which were homo-epitaxially grown on a ZnO(0001) substrates with varying relatively high oxygen pressure, have been investigated using x-ray magnetic circular dichroism (XMCD) at Co $2p$ core-level absorption edge. The line shapes of the absorption spectra are the same in all the films and indicate that the Co$^{2+}$ ions substitute for the Zn sites. The magnetic-field and temperature dependences of the XMCD intensity are consistent with the magnetization measurements, indicating that except for Co there are no additional sources for the magnetic moment, and demonstrate the coexistence of paramagnetic and ferromagnetic components in the homo-epitaxial Zn$_{1-x}$Co$_{x}$O thin films, in contrast to the ferromagnetism in the hetero-epitaxial Zn$_{1-x}$Co$_{x}$O films studied previously. The analysis of the XMCD intensities using the Curie-Weiss law reveals the presence of antiferromagnetic interaction between the paramagnetic Co ions. Missing XMCD intensities and magnetization signals indicate that most of Co ions are non-magnetic probably because they are strongly coupled antiferromagnetically with each other. Annealing in a high vacuum reduces both the paramagnetic and ferromagnetic signals. We attribute the reductions to thermal diffusion and aggregation of Co ions with antiferromagnetic nanoclusters in Zn$_{1-x}$Co$_{x}$O.Comment: 21 pages, 7 figures, accepted for Physical Review