Cell Ca2+ response to luminal vasopressin in cortical collecting tubule principal cells

Cell Ca2+ response to luminal vasopressin in cortical collecting tubule principal cells. Although vasopressin V1 receptors have been shown to exist in both luminal and basolateral membranes of rabbit cortical collecting duct (CCD), exact cell types having V1 receptors remain unestablished. To identify the distribution of V1 receptor by cytoplasmic Ca2+ response, we utilized the confocal imaging system in the microperfused rabbit CCD. Basolateral application of arginine vasopressin (AVP) increased [Ca2+]i mainly in one group of cells which were not stained by fluorescein-isothiocyanate-conjugated peanut agglutinin. Luminal application of AVP increased [Ca2+]i in the same cells which responded to basolateral AVP. These findings provide evidence that V1 receptors, as defined by the [Ca2+]i response, exist in both luminal and basolateral membranes of the rabbit principal cell

Statistical Mechanics of Self--Gravitating System : Cluster Expansion Method

We study statistical mechanics of the self--gravitating system applying the cluster expansion method developed in solid state physics. By summing infinite series of diagrams, we derive a complex free energy whose imaginary part is related to the relaxation time of the system. Summation of another series yields two--point correlation function whose correlation length is essentially given by the Jeans wavelength of the system.Comment: 4 pages including 2 eps figures, RevTe

Is Galaxy Distribution Non-extensive and Non-Gaussian?

Self gravitating systems (SGS) in the Universe are generally thought to be non-extensive, and often show long-tails in various distribution functions. In principle, these non-Boltzmann properties are naturally expected from the peculiar property of gravity, long-range and unshielded. Therefore the ordinary Boltzmann statistical mechanics would not be applicable for these self gravitating systems (SGS) in its naive form. In order to step further, we quantitatively investigate the above two properties, non-extensivity and long-tails, by explicitly introducing various models of statistical mechanics. We use the data of CfA II South redshift survey and apply the count-in-cell method. We study four statistical mechanics, (1) Boltzmann, (2) Fractal, (3) R\'enyi, and (4) Tsallis, and use Akaike information criteria (AIC) for the fair comparison.Comment: 19 pages, 9 figure

A new digital control DC-DC converter with peak current -injected control

This paper presents a new digital control circuit which is able to detect the peak switch current of the high frequency switching dc-dc converter. In this proposed digital control circuit, the peak current-injected control is realized using the combination of the simple dual pulse width modulation analog-to-digital signal converter and the programmed delay circuit. In 100kHz digitally controlled dc-dc converter, it is seen in simulation that the proposed method has no overshoot of the output voltage and the convergence time that the output voltage is settled to steady-state is only 30μs. The difference between the transient time of the proposed circuit and that of the conventional method is an order of magnitude. Furthermore, the ratio of resolution of the DPWM generator against the output voltage is 0.27% and is satisfied to apply the commercial power supply unit.INTELEC 2008 - 2008 IEEE 30th International Telecommunications Energy Conference : San Diego, CA, 2008.09.14-2008.09.1

Redox-sensitive transient receptor potential channels in oxygen sensing and adaptation

Regulation of ion channels is central to the mechanisms that underlie immediate acute physiological responses to changes in the availability of molecular oxygen (O2). A group of cation-permeable channels that are formed by transient receptor potential (TRP) proteins have been characterized as exquisite sensors of redox reactive species and as efficient actuators of electric/ionic signals in vivo. In this review, we first discuss how redox-sensitive TRP channels such as TRPA1 have recently emerged as sensors of the relatively inert oxidant O2. With regard to the physiological significance of O2 sensor TRP channels, vagal TRPA1 channels are mainly discussed with respect to their role in respiratory regulation in comparison with canonical pathways in glomus cells of the carotid body, which is a well-established O2-sensing organ. TRPM7 channels are discussed regarding hypoxia-sensing function in ischemic cell death. Also, ubiquitous expression of TRPA1 and TRPM7 together with their physiological relevance in the body is examined. Finally, based upon these studies on TRP channels, we propose a hypothesis of “O2 remodeling.” The hypothesis is that cells detect deviation of O2 availability from appropriate levels via sensors and adjust local O2 environments in vivo by controlling supply and consumption of O2 via pathways comprising cellular signals and transcription factors downstream of sensors, which consequently optimize physiological functions. This new insight into O2 adaptation through ion channels, particularly TRPs, may foster a paradigm shift in our understanding in the biological significance of O2

Evaluation of drop in official air temperature record at Okayama caused by relocation of observation field of Okayama Local Meteorological Observatory - By comparison with records observed at surrounding points -

Statistical change in official temperature records at Okayama City caused by relocation of meteorological observation field of Meteorological Agency was evaluated. The observation field of Okayama local meteorological observatory was moved to the Tsushima Campus of Okayama University from the downtown area of Okayama City in March, 2015. Comparison between the air temperature records measured at meteorological agency station and the records at Tanjo Pond in Tsushima Campus, showed 0.56 ℃ drop in annual average before and after relocation. Moreover, comparison between the records of Okayama local meteorological observatory and that at the surrounding meteorological observing 9 stations showed 0.55 ℃ drop in annual average. Those results suggest that the relocation dropped annual average of air temperature by about 0.6 ℃

Dynamic characteristics of DC-DC converter with novel digital peak current-injected control

This paper presents the dynamic characteristics of the proposed digital control current mode de-de converter. In the proposed novel digital control circuit, the peak current-injected control is realized using the combination of the simple dual A-Dsignal converter and the programmed delay circuit. In 100kHz digitally controlled de-de converter, it is seen in simulation that the proposed method has no overshoot of the output voltage and the convergencetime that the output voltage is settled to steady-state is only 151J1S. The difference between the transient time of the proposed circuit and that of the conventionalmethod is an order of magnitude. Furthermore, the ratio of resolution of the DPWM generator against the output voltage is 0.27% and is satisfied to apply the commercial power supply unit.INTELEC 2009 - 2009 International Telecommunications Energy Conference : Incheon, South Korea, 2009.10.18-2009.10.2

Direct Imaging Explorations for Companions around Mid-Late M Stars from the Subaru/IRD Strategic Program

The Subaru telescope is currently performing a strategic program (SSP) using the high-precision near-infrared (NIR) spectrometer IRD to search for exoplanets around nearby mid/late-M~dwarfs via radial velocity (RV) monitoring. As part of the observing strategy for the exoplanet survey, signatures of massive companions such as RV trends are used to reduce the priority of those stars. However, this RV information remains useful for studying the stellar multiplicity of nearby M~dwarfs. To search for companions around such ``deprioritized" M~dwarfs, we observed 14 IRD-SSP targets using Keck/NIRC2 observations with pyramid wavefront sensing at NIR wavelengths, leading to high sensitivity to substellar-mass companions within a few arcseconds. We detected two new companions (LSPM~J1002+1459~B and LSPM~J2204+1505~B) and two new candidates that are likely companions (LSPM~J0825+6902~B and LSPM~J1645+0444~B) as well as one known companion. Including two known companions resolved by the IRD fiber injection module camera, we detected seven (four new) companions at projected separations between $\sim2-20$~au in total. A comparison of the colors with the spectral library suggests that LSPM~J2204+1505~B and LSPM~J0825+6902~B are located at the boundary between late-M and early-L spectral types. Our deep high-contrast imaging for targets where no bright companions were resolved did not reveal any additional companion candidates. The NIRC2 detection limits could constrain potential substellar-mass companions ($\sim10-75\ M_{\rm Jup}$) at 10~au or further. The failure with Keck/NIRC2 around the IRD-SSP stars having significant RV trends makes these objects promising targets for further RV monitoring or deeper imaging with JWST to search for smaller-mass companions below the NIRC2 detection limits.Comment: 16 pages, 8 figures, accepted for publication in A