696 research outputs found

    Interstitium: site of steroid synthesis in the ovary of the long term hypophysectomized hamster

    Get PDF
    The ovaries of hamsters hypophysectomized (H̅) on the afternoon of proestrus synthesize in vitro substantial amounts of progesterone for as long as 20 days post-H̅ (Taya and Greenwald, 1979b). The purpose of the present study was to identify by histochemistry and ultrastructure the ovarian cell type which still possessed the enzymes capable of steroidogenesis despite the long term absence of gonadotropins. After Day 6 post-H̅, the ovaries contained interstitium and viable and atretic small preantral follicles. The viable preantral follicles were histochemically devoid of Δ 5-3β -hydroxysteroid dehydrogenase (3β -HSDH). Histochemically, there were no appreciable changes in lipids in the interstitial gland cells (IGC) until Day 20 post-H̅, followed by a slight decrease by Day 30. The 3β -HSDH activity in the IGC showed no appreciable changes until Day 6 and thereafter decreased gradually until Day 30. Trace amounts of glucose-6-phosphate dehydrogenase were found in the IGC until Day 6 and thereafter the enzyme was undetectable. The IGC contained only trace amounts of acid phosphatase until Day 10, followed by a gradual increase by Day 30. A single i.p. injection of 5 μg ovine LH on Day 10, 20 or 30 resulted 3 h later in dramatic increases in the concentration of serum progesterone and ovarian progesterone and testosterone but not estradiol-17β . Concomitantly, the depletion of lipid droplets in viable interstitial cells was observed by histochemical and ultrastructural criteria. However, lipid accumulations in degenerating interstitial cells and atretic granulosa cells were unaffected by LH treatment. These data indicate that the interstitium is an active steroidogenic tissue for at least 30 days post-H̅ and that LH can rapidly stimulate synthesis and secretion of progesterone and testosterone by the interstitium in long term hypophysectomized hamsters

    An Intermediate-band imaging survey for high-redshift Lyman Alpha Emitters: The Mahoroba-11

    Full text link
    We present results of our intermediate-band optical imaging survey for high-zz Lyα\alpha emitters (LAEs) using the prime focus camera, Suprime-Cam, on the 8.2m Subaru Telescope. In our survey, we use eleven filters; four broad-band filters (BB, RcR_{\rm c}, ii^\prime, and zz^\prime) and seven intermediate-band filters covering from 500 nm to 720 nm; we call this imaging program as the Mahoroba-11. The seven intermediate-band filters are selected from the IA filter series that is the Suprime-Cam intermediate-band filter system whose spectral resolution is R=23R = 23. Our survey has been made in a 34×2734^\prime \times 27^\prime sky area in the Subaru XMM Newton Deep Survey field. We have found 409 IA-excess objects that provide us a large photometric sample of strong emission-line objects. Applying the photometric redshift method to this sample, we obtained a new sample of 198 LAE candidates at 3<z<53 < z < 5. We found that there is no evidence for evolution of the number density and the star formation rate density for LAEs with logL(Lyα)(ergs1)>42.67\log L({\rm Ly}\alpha) ({\rm erg s^{-1}}) > 42.67 between z3z \sim 3 and 5.Comment: 46 pages, 15 figures, PASJ, Vol.57, No.6, in pres

    Attentive Neural Architecture Incorporating Song Features For Music Recommendation

    Full text link
    Recommender Systems are an integral part of music sharing platforms. Often the aim of these systems is to increase the time, the user spends on the platform and hence having a high commercial value. The systems which aim at increasing the average time a user spends on the platform often need to recommend songs which the user might want to listen to next at each point in time. This is different from recommendation systems which try to predict the item which might be of interest to the user at some point in the user lifetime but not necessarily in the very near future. Prediction of the next song the user might like requires some kind of modeling of the user interests at the given point of time. Attentive neural networks have been exploiting the sequence in which the items were selected by the user to model the implicit short-term interests of the user for the task of next item prediction, however we feel that the features of the songs occurring in the sequence could also convey some important information about the short-term user interest which only the items cannot. In this direction, we propose a novel attentive neural architecture which in addition to the sequence of items selected by the user, uses the features of these items to better learn the user short-term preferences and recommend the next song to the user.Comment: Accepted as a paper at the 12th ACM Conference on Recommender Systems (RecSys 18

    Vesivirus 2117 capsids more closely resemble sapovirus and lagovirus particles than other known vesivirus structures

    Get PDF
    Vesivirus 2117 is an adventitious agent that in 2009, was identified as a contaminant of CHO cells propagated in bioreactors at a pharmaceutical manufacturing plant belonging to Genzyme. The consequent interruption in supply of Fabrazyme and Cerezyme (drugs used to treat Fabry and Gaucher disease respectively), caused significant economic losses. Vesivirus 2117 is a member of the Caliciviridae; a family of small icosahedral viruses encoding a positive sense RNA genome. We have used cryo-electron microscopy and three dimensional image reconstruction to calculate a structure of vesivirus 2117 virus like particles as well as feline calicivirus and a chimeric sapovirus. We present a structural comparison of several members of the Caliciviridae, showing that the distal P domain of vesivirus 2117 is morphologically distinct from that seen in other known vesivirus structures. Furthermore, at intermediate resolutions we found a high level of structural similarity between vesivirus 2117 and Caliciviridae from other genera, such as sapovirus and rabbit haemorrhagic disease virus. Phylogenetic analysis confirms vesivirus 2117 as a vesivirus closely related to canine vesiviruses. We postulate that morphological differences in virion structure seen between vesivirus clades may reflect differences in receptor usage

    The Halpha Luminosity Function of the Galaxy Cluster Abell 521 at z = 0.25

    Full text link
    We present an optical multicolor-imaging study of the galaxy cluster Abell 521 at z=0.25z = 0.25, using Suprime-Cam on the Subaru Telescope, covering an area of 32×2032 \times 20 arcmin2^2 (9.4×5.8h5029.4 \times 5.8 h_{50}^{-2} Mpc2^2 at z=0.25z = 0.25). Our imaging data taken with both a narrow-band filter, NB816NB816 (λ0=8150\lambda_0 = 8150\AA and Δλ=120\Delta \lambda = 120\AA), and broad-band filters, B,V,RC,iB,V,R_{\rm C}, i^\prime, and zz^\prime allow us to find 165 Hα\alpha emitters. We obtain the Hα\alpha luminosity function (LF) for the cluster galaxies within 2 Mpc; the Schechter parameters are α=0.75±0.23\alpha = -0.75 \pm 0.23, ϕ=100.25±0.20\phi^\star = 10^{-0.25 \pm 0.20} Mpc3^{-3}, and L=1042.03±0.17L^\star = 10^{42.03 \pm 0.17} erg s1^{-1}. Although the faint end slope, α\alpha, is consistent with that of the local cluster Hα\alpha LFs, the characteristic luminosity, LL^\star, is about 6 times (or 2\approx 2 mag) brighter. This strong evolution implies that Abell 521 contains more active star-forming galaxies than the local clusters, being consistent with the observed Butcher-Oemler effect. However, the bright LL^\star of Abell 521 may be, at least in part, due to the dynamical condition of this cluster.Comment: 21 pages, 7 figures, ApJ, Part 1, in pres

    Are Two z~6 Quasars Gravitationally Lensed ?

    Full text link
    Several high-z (z > 5.7) quasars have been found in the course of Sloan Digital Sky Survey. The presence of such very high-z quasars is expected to give constraints on early structure formation. On one hand, it is suggested that these most luminous objects at high redshift are biased toward the highly magnified objects by gravitational lensing. To clarify the effect of gravitational lensing on the high-z quasars, we began the imaging survey of intervening lensing galaxies. Indeed our previous optical image showed that SDSSp J104433.04+012502.2 at z=5.74 is gravitationally magnified by a factor 2. In this paper, we report our new optical imaging of other two high-z quasars, SDSSp J103027.10+052455.0 at z=6.28 and SDSSp J130608.26+035626.3 at z=5.99. Since we find neither intervening galaxy nor counter image with i^{\prime} < 25.4-25.8 around each quasar, we conclude that they are not strongly magnified regardless that a lens galaxy is dusty.Comment: 10 pages, 8 figures, Accepted for PAS

    RNA interference of gonadotropin-inhibitory hormone gene induces arousal in songbirds.

    Get PDF
    Gonadotropin-inhibitory hormone (GnIH) was originally identified in quail as a hypothalamic neuropeptide inhibitor of pituitary gonadotropin synthesis and release. However, GnIH neuronal fibers do not only terminate in the median eminence to control anterior pituitary function but also extend widely in the brain, suggesting it has multiple roles in the regulation of behavior. To identify the role of GnIH neurons in the regulation of behavior, we investigated the effect of RNA interference (RNAi) of the GnIH gene on the behavior of white-crowned sparrows, a highly social songbird species. Administration of small interfering RNA against GnIH precursor mRNA into the third ventricle of male and female birds reduced resting time, spontaneous production of complex vocalizations, and stimulated brief agonistic vocalizations. GnIH RNAi further enhanced song production of short duration in male birds when they were challenged by playbacks of novel male songs. These behaviors resembled those of breeding birds during territorial defense. The overall results suggest that GnIH gene silencing induces arousal. In addition, the activities of male and female birds were negatively correlated with GnIH mRNA expression in the paraventricular nucleus. Density of GnIH neuronal fibers in the ventral tegmental area was decreased by GnIH RNAi treatment in female birds, and the number of gonadotropin-releasing hormone neurons that received close appositions of GnIH neuronal fiber terminals was negatively correlated with the activity of male birds. In summary, GnIH may decrease arousal level resulting in the inhibition of specific motivated behavior such as in reproductive contexts

    Early Spectroscopy of the 2010 Outburst of U Scorpii

    Full text link
    We present early spectroscopy of the recurrent nova U~Sco during the outburst in 2010. We successfully obtained time-series spectra at td=t_{\rm d}=0.37--0.44~d, where tdt_{\rm d} denotes the time from the discovery of the present outburst. This is the first time-resolved spectroscopy on the first night of U Sco outbursts. At td0.4t_{\rm d}\sim 0.4~d the Hα\alpha line consists of a blue-shifted (5000-5000 km s1^{-1}) narrow absorption component and a wide emission component having triple peaks, a blue (3000\sim -3000 km s1^{-1}), a central (0\sim 0 km s1^{-1}) and a red (+3000\sim +3000 km s1^{-1}) ones. The blue and red peaks developed more rapidly than the central one during the first night. This rapid variation would be caused by the growth of aspherical wind produced during the earliest stage of the outburst. At td=1.4t_{\rm d}=1.4~d the Hα\alpha line has a nearly flat-topped profile with weak blue and red peaks at ±3000\sim \pm 3000 km s1^{-1}. This profile can be attributed to a nearly spherical shell, while the asphericity growing on the first night still remains. The wind asphericity is less significant after td=9t_{\rm d}=9 d.Comment: 5 pages, 3 figures, Accepted for publication of PASJ Letter
    corecore