The Locus of Highly Accreting AGNs on the M_BH--sigma Plane: Selections, Limitations, and Implications

We re-examine the locus of narrow line Seyfert 1 galaxies on the M_BH--sigma (black hole mass--bulge velocity dispersion) plane in the light of the results from large new optically selected samples. We find that (1) soft X-ray selected NLS1s have a lower ratio of BH mass to \sigma^{4}_{[OIII]} than broad line Seyfert 1 galaxies; this remains a robust statistical result contrary to recent claims otherwise; (2) optically selected NLS1s have systematically lower Eddington luminosity ratio compared to X-ray selected NLS1s; and (3) as a result, the locus of NLS1s on the M_BH--sigma plane is affected by selection effects. We argue that there is no single explanation for the origin of the M_BH--sigma relation; instead tracks of galaxies on the M_BH--sigma plane differ with redshift, consistent with the downsizing of AGN activity. If these results at face value are incorrect, then the data imply that AGNs with high Eddington accretion reside preferentially in relatively late type galaxies at the present epoch, perhaps a more interesting result and a challenge to theoretical models.Comment: To appear in Ap

The Composite Spectrum of Strong Lyman-alpha Forest Absorbers

We present a new method for probing the physical conditions and metal enrichment of the Intergalactic Medium: the composite spectrum of Ly-alpha forest absorbers. We apply this technique to a sample of 9480 Ly-alpha absorbers with redshift 2 < z < 3.5 identified in the spectra of 13,279 high-redshift quasars from the Sloan Digital Sky Survey (SDSS) Fifth Data Release (DR5). Absorbers are selected as local minima in the spectra with 2.4 < tau_Ly-alpha < 4.0; at SDSS resolution (~ 150km/s FWHM), these absorbers are blends of systems that are individually weaker. In the stacked spectra we detect seven Lyman-series lines and metal lines of O VI, N V, C IV, C III, Si IV, C II, Al II, Si II, Fe II, Mg II, and O I. Many of these lines have peak optical depths of < 0.02, but they are nonetheless detected at high statistical significance. Modeling the Lyman-series measurements implies that our selected systems have total H I column densities N_HI ~ 10^15.4cm-2. Assuming typical physical conditions rho / = 10, T = 10^4 - 10^4.5 K, and [Fe/H]= -2 yields reasonable agreement with the line strengths of high-ionization species, but it underpredicts the low-ionization species by two orders of magnitude or more. This discrepancy suggests that the low ionization lines arise in dense, cool, metal-rich clumps, present in some absorption systems.Comment: 7 pages, 4 figures, 1 table, accepted by ApJL, revisions mad

Effect of different factors on in vitro growth and shoot proliferation of guava (Psidium guajava L.) cv. Allahabad Safeda

In the present experiment an attempt has been made to optimize the effect of different medium, levels of sucrose, pH, adenine sulphate and light intensity for culture establishment and shoot proliferation in guava using nodal segment explants. Culture establishment was greatly influenced by media types. Maximum establishment ofexplants (74.57%) was recorded on MS medium supplemented with 2.0 mg/l BAP + 0.2 mg/l IBA. In proliferation study, the maximum shoot proliferation was observed in MS + 1 mg/l BAP + 0.25 mg/l GA3. Sucrose 3% was found to be more favorable for maximum proliferation and growth of shoots moreover, it was reduced gradually as increased or decreased levels of sucrose from 30 g/l. among the various pH levels tested, pH 5.5 recorded maximum number of shoots (8.08) and maximum length of shoots (3.75 cm).In proliferation medium the length of shoot, numbers of shoots and growth rate were increased as increased the adenine sulphate level in the medium. Maximum proliferation was observed on 160 mg/l adenine sulphate in the medium. High light intensity 3000 lux was found to be most suitable for proper growth of regenerated shoots. Low light intensity (1000 lux) resulted in stunted growth. All the above factors significantly influenced shoot multiplication and growth. Thus, optimization of these factors showed significantly increased number of shoots and rapid multiplication. This could be useful for the in vitro production of cost effective healthy planting material of guav

A preliminary study on identifying specific risk factors of post-partum depression

Background: Pregnancy and childbirth are important events in the life of a woman and also highly vulnerable period of various physiological and psychological illnesses. Several literatures propound that 22% young Indian mothers are showing depressive symptoms after delivery. The consequence of maternal depression is adverse both for mother and development of the child. Objective of this study was to examine the social and obstetric factors contributing post-partum depression.Methods: Women, 18-35 years of age, having four days to one-year postpartum period was taken from the tertiary care hospital settings. Terminal illness, still birth delivery and comorbid psychiatric illness was excluded. Screening and diagnosis of postpartum depression done based on international classification of diseases (ICD 10) using Edinburgh post-natal depression scale (EPDS). A comparative approach by the means of descriptive statistics was implied for data analysis where mothers with depressive symptoms are experimental group and non-depressed mothers were acted as the controls.Results: Study findings indicated a statistically significant association between postpartum depression and risk factors such as occupation and average social economic class, first time delivery.Conclusions: It is a preliminary study in a restricted geographical area, not covering the neurobiological risk factors of postpartum depression. Hence, the future study will focus on the large sample size in a multi areal population for assuring the accuracy of the result

Constructing a Sense of Story: One Block at a Time

This photo essay focuses upon the literacy practices of two groups of preschoolers as they built, illustrated, and dictated stories in response to their participation in a “Castle Project.” Data, including literacy artifacts, photodocumentation, sociodramatic play scenarios, and conversations are qualitatively analyzed, coded, and evaluated over a three month period. We use a narrative approach to describe the three- and four-year-olds’ talk, actions, and ideas, and the ways block play facilitated their sense of story and motivation to write. We suggest a reciprocity of thinking between the building and composing processes. Preschoolers’ story ideas, we deduce, were conceptualized and rehearsed in the block corner. We illustrate the power of emergent literacy learners to construct understandings of the world with the support and guidance of their teacher, using inquiry based and arts infused approaches to teaching and learning

Discovery of Associated Absorption Lines in an X-Ray Warm Absorber: Hubble Space Telescope Faint Object Spectrograph Observations of MR 2251–178

The presence of a "warm absorber" was first suggested to explain spectral variability in an X-ray spectrum of the radio-quiet quasi-stellar object (QSO) MR 2251-178. A unified picture, in which X-ray warm absorbers and "intrinsic" UV absorbers are the same, offers the opportunity to probe the nuclear environment of active galactic nuclei. To test this scenario and understand the physical properties of the absorber, we obtained a UV spectrum of MR 2251-178 with the Faint Object Spectrograph on board the Hubble Space Telescope (HST). The HST spectrum clearly shows absorption due to Lyα, N V, and C IV, blueshifted by 300 km s^-1 from the emission redshift of the QSO. The rarity of both X-ray and UV absorbers in radio-quiet QSOs suggests these absorbers are physically related, if not identical. Assuming the unified scenario, we place constraints on the physical parameters of the absorber and conclude the mass outflow rate is essentially the same as the accretion rate in MR 2251-178