ALBERT

Description: Spontaneously hypertensive rats (SHR) are known to be blood pressure sensitive to dietary calcium. The effects of dietary calcium on platelet aggregation and intracellular Ca2+ mobilization were assessed by turbidimetric methods and fura-2 methods, respectively, in washed platelets of SHR. Ca2+ ATPase activity was examined in aortic membrane fractions. Six weeks of dietary calcium supplementation attenuated the increase of systolic blood pressure (SBP 199 +/- 16 v 170 +/- 9 mm Hg, P 〈 .001) and thrombin-induced platelet aggregation (84.5 +/- 3.7 v 73.7 +/- 7.4%, P 〈 .004) at 9 weeks of age. The ionomycin-induced intracellular calcium ([Ca2+]i) peak in the absence of external Ca2+, which reflects [Ca2+]i storage size, and thrombin-evoked [Ca2+]i release from [Ca2+]i storage were decreased by 2.0% Ca diet (472 +/- 55 v 370 +/- 23 nmol/L, P 〈 .001, 339 +/- 29 v 278 +/- 33 nmol/L, P 〈 .002). In addition, SBP was positively correlated with platelet aggregation (r = 0.703, P = .0088), thrombin-evoked [Ca2+]i (r = 0.739, P = .0044), and ionomycin-induced [Ca2+]i (r = 0.591, P = .0415), respectively. However, there was no significant effect of dietary calcium on Ca2+-ATPase activity in aortic membranes. These results suggest that dietary calcium supplementation had a beneficial effect on platelets of SHR by attenuating [Ca2+]i mobilization from [Ca2+]i storage. The hypotensive effect of dietary calcium might be associated with attenuated [Ca2+]i mobilization in SHR.

Description: The quantity and quality of light required for light-stimulated cell expansion in leaves of Phaseolus vulgaris L. have been determined. Seedlings were grown in dim red light (RL; 4 micromoles photons m-2 s-1) until cell division in the primary leaves was completed, then excised discs were incubated in 10 mM sucrose plus 10 mM KCl in a variety of light treatments. The growth response of discs exposed to continuous white light (WL) for 16 h was saturated at 100 micromoles m-2 s-1, and did not show reciprocity. Extensive, but not continuous, illumination was needed for maximal growth. The wavelength dependence of disc expansion was determined from fluence-response curves obtained from 380 to 730 nm provided by the Okazaki Large Spectrograph. Blue (BL; 460 nm) and red light (RL; 660 nm) were most effective in promoting leaf cell growth, both in photosynthetically active and inhibited leaf discs. Far-red light (FR; 730 nm) reduced the effectiveness of RL, but not BL, indicating that phytochrome and a separate blue-light receptor mediate expansion of leaf cells.

Description: Quantitative analysis of the electron beam-induced current and the dependence of the effective diffusion length of the minority carriers on the penetration depth of the electron beam were employed for the analysis of the carrier recombination characteristics in heavily doped silicon layers. The analysis is based on the concept of the effective excitation strength of the carriers which takes into consideration all possible recombination sources. Two dimensional mapping of the surface recombination velocity of P-diffused Si layers will be presented together with a three dimensional mapping of minority carrier lifetime in ion implanted Si. Layers heavily doped with As exhibit improved recombination characteristics as compared to those of the layers doped with P.

Description: Quantitative analysis of the electron beam induced current in conjunction with high-resolution scanning makes it possible to evaluate the minority-carrier lifetime three dimensionally in the bulk and the surface recombination velocity two dimensionally, with a high spacial resolution. The analysis is based on the concept of the effective excitation strength of the carriers which takes into consideration all possible recombination sources. Two-dimensional mapping of the surface recombination velocity of phosphorus-diffused silicon diodes is presented as well as a three-dimensional mapping of the changes in the minority-carrier lifetime in ion-implanted silicon.

Description: We report an orbital characterization of GJ1108Aab that is a low-mass binary system in the pre-main-sequence phase. Via the combination of astrometry using adaptive optics and radial velocity measurements, an eccentric orbital solution of e = 0.63 is obtained, which might be induced by the KozaiLidov mechanism with a widely separated GJ1108B system. Combined with several observed properties, we conrm that the system is indeed young. Columba is the most probable moving group, to which the GJ1108A system belongs, although its membership to the group has not been established. If the age of Columba is assumed for GJ1108A, the dynamical masses of both GJ1108Aa and GJ1108Ab (M(sub dynamical,GJ1108Aa) = 0.72 0.04 Solar Mass and M(sub dynamical,GJ1108Ab) = 0.30 0.03 Solar Mass) are more massive than what an evolutionary model predicts based on the age and luminosities. We consider that the discrepancy in mass comparison can be attributed to an age uncertainty; the system is likely older than stars in Columba, and effects that are not implemented in classical models such as accretion history and magnetic activity are not preferred to explain the mass discrepancy. We also discuss the performance of the evolutionary model by compiling similar low-mass objects in the evolutionary state based on the literature. Consequently, it is suggested that the current model on average reproduces the mass of resolved low-mass binaries without any signicant offsets.

Description: A method was developed and successfully tested for the determination of the effective surface recombination velocity of silicon layers doped by diffusion of phosphorus to a level of 10 to the 19th to 10 to the 21st per cu cm. The effective recombination velocity was obtained from the dependence of the electron-beam-induced current on the penetration of the electron beam of a scanning electron microscope. A special silicon diode was constructed which permitted the collection at the p-n junction of the carriers excited by the electron beam. This diode also permitted the study of the effects of surface preparation on the effective surface recombination velocity.

Description: We present the direct imaging discovery of an extrasolar planet, or possible low-mass brown dwarf, at a projected separation of 55 plus or minus 2 AU (1."058 plus or minus 0."007) from the B9-type star K And. The planet was detected with Subaru/HiCIAO (Subaru/High Contrast Instrument for the Subaru Next Generation Adaptive Optics) during the SEEDS (Strategic Exploration of Exoplanets and Disks with Subaru Telescope/HiCIAO) survey and confirmed as a bound companion via common proper motion measurements. Observed near-infrared magnitudes of J equals 16.3 plus or minus 0.3, H equals 15.2 plus or minus 0.2, K (sub s) = 14.6 plus or minus 0.4, and L prime equals 13.12 plus or minus 0.09 indicate a temperature of approximately 1700 degrees Kelvin. The galactic kinematics of the host star are consistent with membership in the Columba Association, implying a corresponding age of 30 (exp from plus 20 to minus10) Myr. The systems age, combined with the companion photometry, points to a model-dependent companion mass approximately 12.8 times the mass of Jupiter. The host stars estimated mass of 2.4 to 2.5 times the mass of the sun places it among the most massive stars ever known to harbor an extrasolar planet or low-mass brown dwarf. While the mass of the companion is close to the deuterium burning limit, its mass ratio, orbital separation, and likely planet-like formation scenario imply that it may be best defined as a super-Jupiter with properties similar to other recently discovered companions to massive stars.

Description: The spatial structure of dayside large-scale field-aligned current (FAC) systems is examined by using Viking and Defense Meteorological Satellite Program-F7 (DMSP-F7) data. We focus on four events in which the satellites simultaneously observed postnoon and prenoon three FAC systems: the region 2, the region 1, and the mantle (referred to as midday region O) systems, from equatorward to poleward. These events provide the most solid evidence to date that the midday region O system is a separate and unique FAC system, and is not an extension of the region 1 system from other local times. The events are examined comprehensively by making use of a mulit-instrumental data set, which includes magnetic field, particle flux, electric field, auroral UV image data from the satellites, and the Sondrestrom convection data. The results are summarized as follows: (1) Region 2 currents flow mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPD) at their poleward edge. (2) The region 1 system is located in the core part of the auroral oval and is confined in a relatively narrow range in latitude which includes the convection reversal. The low-latitude boundary layer, possibly including the outer part of the plasma sheet, and the external cusp are the major source regions of dayside region 1 currents. (2) Midday region O currents flow on open field lines and are collocated with the shear of antisunward convection flows with velocites decreasing poleward. On the basis of these results we support the view that both prenoon and postnoon current systems consist of the three-sheet structure when the disctortion ofthe convection pattern associated with interplanetary magnetic field (IMF) B(sub Y) is small and both morningside and eveningside convection cells are crescent-shaped. We also propose that the midday region O and a part of the region 1 systems are closely coupled to the same source.

Description: A system of four current sheets of large-scale field-aligned currents (FACs) was discovered in the data set of simultaneous Viking and Defense Meteorological Satellire Program-F7 (DMSP-F7) crossing of the dayside high-latitude region. This paper reports four examples of this system that were observed in the prenoon sector. The flow polarities of FACs are upward, downward, upward, and downward, from equatorward to poleward. The lowest-latitude upward current is flowing mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPS) at its poleward edge, andis interpreted as a region 2 current. The pair of downward and upward FACs in the middle of te structure are collocated with structured electron precipitation. The precipitation of high-energy (greater than 1 keV) electrons is more intense in the lower-latitude downward current sheet. The highest-latitude downward flowing current sheet is located in a weak, low-energy particle precipitation region, suggesting that this current is flowing on open field lines. Simulaneous observations in the postnoon local time sector reveal the standard three-sheet structure of FACs, sometimes described as region 2, region 1, and mantle (referred to the midday region O) currents. A high correlation was found between the occurrence of the four FAC sheet structure and negative interplanetary magnetic field (IMF) B(sub Y). We discuss the FAC structurein terms of three types of convection cells: the merging, viscous, andlobe cells. During strongly negative IMF B(sub Y), two convection reversals exist in the prenoon sector; one is inside the viscous cell, and the other is between the viscous cell and the lobe cell. This structure of convection flow is supported by the Viking electric field and auroral UV image data. Based on the convection pattern, the four FAC sheet structure is interpreted as the latitude overlap of midday and morning FAC systems. We suggest that the for-current sheet structure is common in a certain prenoon localtime sector during strongly negative IMF B(sub Y).

Description: The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption 10 times, including yearly eruptions from 2008 to 2014. With a measured recurrence period of Prec = 351+/-13 days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations of the 2013 and 2014 eruptions, we initiated a campaign to ensure early detection of the predicted 2015 eruption, which triggered ambitious ground- and space-based follow-up programs. In this paper we present the 2015 detection, visible to near-infrared photometry and visible spectroscopy, and ultraviolet and X-ray observations from the Swift observatory. The LCOGT 2 m (Hawaii) discovered the 2015 eruption, estimated to have commenced at August 28.28 +/- 0.12 UT. The 2013-2015 eruptions are remarkably similar at all wavelengths. New early spectroscopic observations reveal short-lived emission from material with velocities approx. 13,000 km/s, possibly collimated outflows. Photometric and spectroscopic observations of the eruption provide strong evidence supporting a red giant donor. An apparently stochastic variability during the early supersoft X-ray phase was comparable in amplitude and duration to past eruptions, but the 2013 and 2015 eruptions show evidence of a brief flux dip during this phase. The multi-eruption Swift/XRT spectra show tentative evidence of high-ionization emission lines above a high-temperature continuum. Following Henze et al. (2015a), the updated recurrence period based on all known eruptions is Prec 174 +/- 10 days, and we expect the next eruption of M31N 2008-12a to occur around 2016 mid-September.