ABSTRACT
OJ 287 is a BL Lacertae type quasar in which the active galactic nucleus (AGN) outshines the host galaxy by an order of magnitude. The only exception to this may be at minimum light when the ...AGN activity is so low that the host galaxy may make quite a considerable contribution to the photometric intensity of the source. Such a dip or a fade in the intensity of OJ 287 occurred in 2017 November, when its brightness was about 1.75 mag lower than the recent mean level. We compare the observations of this fade with similar fades in OJ 287 observed earlier in 1989, 1999, and 2010. It appears that there is a relatively strong reddening of the B− V colours of OJ 287 when its V-band brightness drops below magnitude 17. Similar changes are also seen in V− R, V− I, and R− I colours during these deep fades. These data support the conclusion that the total magnitude of the host galaxy is V = 18.0 ± 0.3, corresponding to MK = −26.5 ± 0.3 in the K-band. This is in agreement with the results, obtained using the integrated surface brightness method, from recent surface photometry of the host. These results should encourage us to use the colour separation method also in other host galaxies with strongly variable AGN. In the case of OJ 287, both the host galaxy and its central black hole are among the biggest known, and its position in the black hole mass–galaxy mass diagram lies close to the mean correlation.
We present the design and performance of the High Dispersion Spectrograph (HDS) of the Subaru Telescope. HDS is an echelle spectrograph located at the Nasmyth focus of the telescope. The collimated ...beam size is 272 mm, and the echelle is 300 mm by 840 mm in total size (
$31.6 \,\mathrm{gr} \,\mathrm{mm}^{-1}, R=2.8$
). HDS has two cross-dispersing gratings with
$400 \,\mathrm{gr} \,\mathrm{mm}^{-1}$
and
$250 \,\mathrm{gr} \,\mathrm{mm}^{-1}$
, which are optimized for the blue and red wavelength regions, respectively. The camera is of the catadioptric type system, consisting of three corrector lenses and a mirror. Two EEV-CCD’s with
$4100 \times 2048$
pixels and a pixel size of 13.5
${\mu \mathrm {m}}$
are used as the detector. A standard configuration with a
${0\rlap {.}{}^{\mathrm {\prime \prime }}4}$
slit gives a spectral resolution of
$R=90000$
, and a narrower slit width enables higher resolution of up to
$R \sim 160000$
. The spectrograph has sensitivities from 3000
${Å}$
to 1
${\mu \mathrm {m}}$
, and one exposure covers a range of 1500–2500
${Å}$
, depending on the wavelength region. The throughput of the telescope and the spectrograph, including the efficiency of the detector, is about 13% in 5000–6000
${Å}$
and about 8% at 4000
${Å}$
. The stability of the spectrograph and scattered light level are also reported.
GPR120 and GPR40 are G-protein-coupled receptors whose endogenous ligands are medium- and long-chain free fatty acids, and they are thought to play an important physiological role in insulin release. ...Despite recent progress in understanding their roles, much still remains unclear about their pharmacology, and few specific ligands for GPR120 and GPR40 besides medium- to long-chain fatty acids have been reported so far. To identify new selective ligands for these receptors, more than 80 natural compounds were screened, together with a reference compound MEDICA16, which is known to activate GPR40, by monitoring the extracellular regulated kinase (ERK) and Ca
2+
i
responses in inducible and stable expression cell lines for GPR40 and GPR120, respectively. MEDICA16 selectively activated Ca
2+
i
response in GPR40-expressing cells but not in GPR120-expressing cells. Among the natural compounds tested, grifolin derivatives, grifolic acid and grifolic acid methyl ether, promoted ERK and Ca
2+
i
responses in GPR120-expressing cells, but not in GPR40-expressing cells, and inhibited the α-linolenic acid (LA)-induced ERK and Ca
2+
i
responses in GPR120-expressing cells. Interestingly, in accordance with the pharmacological profiles of these compounds, similar profiles of glucagon-like peptide-1 secretion were seen for mouse enteroendocrine cell line, STC-1 cells, which express GPR120 endogenously. Taken together, these studies identified a selective GPR40 agonist and several GPR120 partial agonists. These compounds would be useful probes to further investigate the physiological and pharmacological functions of GPR40 and GPR120.
Elemental abundance measurements have been obtained for a sample of 18 very metal-poor stars using spectra obtained with the Subaru Telescope High Dispersion Spectrograph. Seventeen stars, among ...which 16 are newly analyzed in the present work, were selected from candidate metal-poor stars identified in the HK survey of Beers and colleagues. The metallicity range covered by our sample is -3.1 Fe/H -2.4. The abundances of carbon, a-elements, and iron-peak elements determined for these stars confirm the trends found by previous work. One exception is the large overabundance of Mg, Al, and Sc found in BS 16934-002, a giant with Fe/H = -2.8. Interestingly, this is the most metal-rich star (by about 1 dex in Fe/H) known with such large overabundances in these elements. Furthermore, BS 16934-002 does not share the large overabundances of carbon that are associated with the two other, otherwise similar, extremely metal-poor stars CS 22949-037 and CS 29498-043. By combining our new results with those of previous studies, we investigate the distribution of neutron-capture elements in very metal-poor stars, focusing on the production of the light neutron-capture elements (e.g., Sr, Y, and Zr). Large scatter is found in the abundance ratios between the light and heavy neutron-capture elements (e.g., Sr/Ba, Y/Eu) for stars with low abundances of heavy neutron-capture elements. Most of these stars have extremely low metallicity (Fe/H -3). By contrast, the observed scatter in these ratios is much smaller in stars with excesses of heavy neutron-capture elements and with higher metallicity. These results can be naturally explained by assuming that two processes independently enriched the neutron-capture elements in the early Galaxy. One process increases both light and heavy neutron-capture elements and affects stars with Fe/H -3, while the other process contributes only to the light neutron-capture elements and affects most stars with Fe/H -3.5. Interestingly, the Y/Zr ratio is similar in stars with high and low abundances of heavy neutron-capture elements. These results provide constraints on modeling of neutron-capture processes, in particular, those responsible for the nucleosynthesis of light neutron-capture elements at very low metallicity.
Difference of 8-hydroxy-deoxyguanosine (8-OH-dG) formation in liver DNA in C3H/HeN and in C57BL/6 mice—fed oxidized lard and dietary oils (soybean and sardine)—was investigated. The blank levels of ...8-OH-dG were higher in C3H/HeN mice (highly sensitive to liver tumorigenesis) than in C57BL/6 mice (resistant strain). The level of 8-OH-dG increased much more in C3H/HeN mice than in the C57BL/6 mice fed by oxidized lard and dietary oil treatment. Feeding oxidized lard and dietary oils increased 8-oxo-guanine DNA glycosylase I (OGG1) and mRNA 8-oxo-dGTPase in C57BL/6 mice. On the other hand, no appreciable change of mRNA in the C3H/HeN mice was observed. The formation differences of 8-OH-dG from the two murine strains fed with oxidized lard and dietary oils may be associated with the different mRNA levels in the DNA repair enzymes because the mRNA levels in the DNA repair enzymes were much lower in C3H/HeN mice than in C57BL/6 mice.
Background: Di-(2-ethylhexyl) phthalate (DEHP) has been widely used in polyvinyl chloride products and is ubiquitous in developed countries. Although maternal exposure to DEHP during fetal and/or ...neonatal periods reportedly affects reproductive and developmental systems, its effects on allergic diseases in offspring remain to be determined. Objectives: In the present study, we examined whether maternal exposure to DEHP during fetal and/or neonatal periods in NC/Nga mice affects atopic dermatitis-like skin lesions related to mite allergen in offspring. Methods: We administered DEHP at a dose of 0, 0.8, 4, 20, or 100 μg/animal/week by intraperitoneal injection into dams during pregnancy (gestation days 0, 7, and 14) and/or lactation (postnatal days 1, 8, and 15). Eight-week-old male offspring of these treated females were injected intradermally with mite allergen into their right ears. We then evaluated clinical scores, ear thickening, histologic findings, and protein expression of eotaxin in the ear. Results: Maternal exposure to a 100-μg dose of DEHP during neonatal periods, but not during fetal periods, enhanced atopic dermatitis-like skin lesions related to mite allergen in males. The results were concomitant with the enhancement of eosinophilic inflammation, mast cell degranulation, and protein expression of eotaxin in overall trend. Conclusion: Maternal exposure to DEHP during neonatal periods can accelerate atopic dermatitis-like skin lesions related to mite allergen in male offspring, possibly via T helper 2$({\rm T}_{{\rm H}}2)\text{-dominant}$responses, which can be responsible, at least in part, for the recent increase in atopic dermatitis.
Context. The quasar 3C 279 is among the most extreme blazars in terms of luminosity and variability of flux at all wavebands. Its variations in flux and polarization are quite complex and therefore ...require intensive monitoring observations at multiple wavebands to characterise and interpret the observed changes. Aims. In this paper, we present radio-to-optical data taken by the WEBT, supplemented by our VLBA and RXTE observations, of 3C 279. Our goal is to use this extensive database to draw inferences regarding the physics of the relativistic jet. Methods. We assemble multifrequency light curves with data from 30 ground-based observatories and the space-based instruments SWIFT (UVOT) and RXTE, along with linear polarization vs. time in the optical R band. In addition, we present a sequence of 22 images (with polarization vectors) at 43 GHz at resolution 0.15 milliarcsec, obtained with the VLBA. We analyse the light curves and polarization, as well as the spectral energy distributions at different epochs, corresponding to different brightness states. Results. We find that the IR-optical-UV continuum spectrum of the variable component corresponds to a power law with a constant slope of -1.6, while in the 2.4–10 keV X-ray band it varies in slope from -1.1 to -1.6. The steepest X-ray spectrum occurs at a flux minimum. During a decline in flux from maximum in late 2006, the optical and 43 GHz core polarization vectors rotate by ~300°. Conclusions. The continuum spectrum agrees with steady injection of relativistic electrons with a power-law energy distribution of slope -3.2 that is steepened to -4.2 at high energies by radiative losses. The X-ray emission at flux minimum comes most likely from a new component that starts in an upstream section of the jet where inverse Compton scattering of seed photons from outside the jet is important. The rotation of the polarization vector implies that the jet contains a helical magnetic field that extends ~20 pc past the 43 GHz core.
With the HDS (High Dispersion Spectrograph) on the Subaru Telescope, we obtained high-resolution optical region spectra of three red giant stars (COS 4, COS 82, and COS 347) in the Ursa Minor dwarf ...spheroidal galaxy. The chemical abundances in these stars were analyzed for 26 elements, including
$\alpha$
-, iron-peak, and neutron-capture elements. All three stars show low abundances of
$\alpha$
-elements (Mg, Si, and Ca), and two stars (COS 82 and COS 347) show high abundances of Mn compared to Galactic halo stars of similar metallicity. One star (COS 4) has been confirmed to be very metal deficient (
$\mathrm{Fe/H} =-2.7$
) and found to show anomalously low abundances of Mn, Cu, and Ba. In another star, COS 82 (
$\mathrm{Fe/H} =-1.5$
), we have found a large excess of heavy neutron-capture elements with a general abundance pattern similar to the scaled solar system
$r$
-process abundance curve. These observational results are rather puzzling: low abundances of
$\alpha$
-elements and high abundance of Mn seem to suggest a significant contribution of SNe Ia at low metallicity, while there is no hint of an
$s$
-process (i.e., AGB stars) contribution, even at
$\mathrm{Fe/H} =-1.5$
, suggesting a peculiar nucleosynthetic history of the UMi dSph galaxy.
Particulate matter (PM) can exacerbate allergic airway diseases. Although health effects of PM with a diameter of less than 100 nm have been focused, few studies have elucidated the correlation ...between the sizes of particles and aggravation of allergic diseases. We investigated the effects of nano particles with a diameter of 14 nm or 56 nm on antigen-related airway inflammation.
ICR mice were divided into six experimental groups. Vehicle, two sizes of carbon nano particles, ovalbumin (OVA), and OVA + nano particles were administered intratracheally. Cellular profile of bronchoalveolar lavage (BAL) fluid, lung histology, expression of cytokines, chemokines, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), and immunoglobulin production were studied.
Nano particles with a diameter of 14 nm or 56 nm aggravated antigen-related airway inflammation characterized by infiltration of eosinophils, neutrophils, and mononuclear cells, and by an increase in the number of goblet cells in the bronchial epithelium. Nano particles with antigen increased protein levels of interleukin (IL)-5, IL-6, and IL-13, eotaxin, macrophage chemoattractant protein (MCP)-1, and regulated on activation and normal T cells expressed and secreted (RANTES) in the lung as compared with antigen alone. The formation of 8-OHdG, a proper marker of oxidative stress, was moderately induced by nano particles or antigen alone, and was markedly enhanced by antigen plus nano particles as compared with nano particles or antigen alone. The aggravation was more prominent with 14 nm of nano particles than with 56 nm of particles in overall trend. Particles with a diameter of 14 nm exhibited adjuvant activity for total IgE and antigen-specific IgG1 and IgE.
Nano particles can aggravate antigen-related airway inflammation and immunoglobulin production, which is more prominent with smaller particles. The enhancement may be mediated, at least partly, by the increased local expression of IL-5 and eotaxin, and also by the modulated expression of IL-13, RANTES, MCP-1, and IL-6.
A computer program has been developed for determining the fundamental model atmosphere parameters (
$T_\mathrm{eff}$
,
$\log g$
,
$v_\mathrm{t}$
,
$\mathrm{Fe/H}$
) of solar-type stars, which is ...based on the equivalent widths for a well-chosen set of Fe i and Fe ii lines. The basic principle of this method is to find the solution in the
$(T_\mathrm{eff}$
,
$\log g$
,
$v_\mathrm{t})$
space, which minimizes the sum of the dispersion of the Fe i abundances and the square of the Fe i–Fe ii abundance difference. An application of this code to the observed solar equivalent widths turned out to yield satisfactory results, which are more or less consistent with the actual parameters of the Sun. The numerical performance of this approach as well as the errors involved in the resulting solutions are discussed.
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