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1
Arageorgis, Aristidis. "Spacetime as a causal set: Universe as a growing block?" Belgrade Philosophical Annual, no. 29 (2016): 33–55. http://dx.doi.org/10.5937/bpa1629033a.
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Earman, John. "Reassessing the Prospects for a Growing Block Model of the Universe." International Studies in the Philosophy of Science 22, no. 2 (July 2008): 135–64. http://dx.doi.org/10.1080/02698590802496680.
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Stoneham, Tom. "Time and Truth: The Presentism-Eternalism Debate." Philosophy 84, no. 2 (April 2009): 201–18. http://dx.doi.org/10.1017/s0031819109000187.
Повний текст джерелаАнотація:
AbstractThere are many questions we can ask about time, but perhaps the most fundamental is whether there are metaphysically interesting differences between past, present and future events. An eternalist believes in a block universe: past, present and future events are all on an equal footing. A gradualist believes in a growing block: he agrees with the eternalist about the past and the present but not about the future. A presentist believes that what is present has a special status. My first claim is that the familiar ways of articulating these views result in there being no substantive disagreement at all between the three parties. I then show that if we accept the controversial truthmaking principle, we can articulate a substantive disagreement. Finally, I apply this way of formulating the debate to related questions such as the open future and determinism, showing that these do not always line up in quite the way one would expect.
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Wandowicz, Mieszko. "Sposób postrzegania przeszłości jako światło dla μελέτη θανάτου. Przyczynek z odniesieniem do myśli parmenidesa z elei (B3)". Hybris 44, № 1 (30 березня 2019): 117–30. http://dx.doi.org/10.18778/1689-4286.44.08.
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Celem mojego artykułu jest przedstawienie refleksji na temat związku między sposobem istnienia przeszłości (tym, jak wolno ją postrzegać) a podejściem do umierania oraz śmierci. Leżąca u podstaw moich rozważań interpretacja Platońskich słów „μελέτη θανάτου” (Fedon, 81 a) w zestawieniu z Parmenidejskim „τὸ γὰρ αὐτὸ νοεῖν ἐστίν τε καὶ εἶναι” (Περί φύσεως, B3) wydaje się dozwolonym i korzystnym intelektualnie rezultatem spojrzenia na te wyimki w świetle ἄσκησις: filozofii pojmowanej jako sposób rozumnego życia-umierania. Jednym z ważnych przesłań filozofii starożytnej zdaje się pogląd, że to, o czym da się pomyśleć, musi istnieć. Wówczas — jako że myślenie (wspominanie) o tym, co wydarzone, jawi się rzetelniejsze niż przewidywanie tego, co dopiero się zdarzy — należy przydać przeszłości odmienny status ontyczny aniżeli przyszłości. Jeśli zaś sięgnąć, dla przykładu, po współczesną teorię rosnącego wszechświata (C. D. Broad; growing [block] universe theory), wtedy wolno — być może — uznać czyjąś śmierć za kolejną warstwę jego istnienia, nie destruującą warstw poprzednich. Pozwala to zmienić postrzeganie przyszłego bądź aktualnego „braku” osoby zmarłej, jak i nieuniknionego zbliżania się (do) śmierci.
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Schawinski, Kevin, C. Megan Urry, Shanil Virani, Paolo Coppi, Steven P. Bamford, Ezequiel Treister, Chris J. Lintott, et al. "Black Hole Growth and Host Galaxy Morphology." Proceedings of the International Astronomical Union 5, S267 (August 2009): 438–41. http://dx.doi.org/10.1017/s1743921310006964.
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AbstractWe use data from large surveys of the local universe (SDSS+Galaxy Zoo) to show that the galaxy–black hole connection is linked to host morphology at a fundamental level. The fraction of early-type galaxies with actively growing black holes, and therefore the AGN duty cycle, declines significantly with increasing black hole mass. Late-type galaxies exhibit the opposite trend: the fraction of actively growing black holes increases with black hole mass.
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Sijacki, Debora, Volker Springel, and Martin G. Haehnelt. "Growing Supermassive Black Holes in Cosmological Simulations of Structure Formation." Proceedings of the International Astronomical Union 5, S267 (August 2009): 445–50. http://dx.doi.org/10.1017/s1743921310006988.
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AbstractWe discuss a numerical model for black hole (BH) growth and feedback that allows simultaneous tracking of the evolution of galaxies and their central BHs in fully cosmological simulations. After describing the main features of the numerical model adopted, we show how BHs in these simulations affect the properties of their host halos and how this in turn impacts the growth of the BHs themselves. We also present results from a set of simulations specifically designed to address the issue of BH assembly in the early Universe and discuss whether or not different extensions of the model, in particular rapidly spinning BHs and gravitational recoils, can hamper the formation of the first bright quasars.
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Hirano, Shingo, Takashi Hosokawa, Naoki Yoshida, and Rolf Kuiper. "Supersonic gas streams enhance the formation of massive black holes in the early universe." Science 357, no. 6358 (September 28, 2017): 1375–78. http://dx.doi.org/10.1126/science.aai9119.
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The origin of super-massive black holes in the early universe remains poorly understood. Gravitational collapse of a massive primordial gas cloud is a promising initial process, but theoretical studies have difficulty growing the black hole fast enough. We report numerical simulations of early black hole formation starting from realistic cosmological conditions. Supersonic gas motions left over from the Big Bang prevent early gas cloud formation until rapid gas condensation is triggered in a protogalactic halo. A protostar is formed in the dense, turbulent gas cloud, and it grows by sporadic mass accretion until it acquires 34,000 solar masses. The massive star ends its life with a catastrophic collapse to leave a black hole—a promising seed for the formation of a monstrous black hole.
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Drouart, G., C. De Breuck, J. Vernet, N. Seymour, M. Lehnert, P. Barthel, F. E. Bauer, et al. "Rapidly growing black holes and host galaxies in the distant Universe from theHerschelRadio Galaxy Evolution Project." Astronomy & Astrophysics 566 (June 2014): A53. http://dx.doi.org/10.1051/0004-6361/201323310.
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Sahani, Amarpreet, Pawan Singh, and Anil Kumar. "Introduction to Blockchain." Journal of Informatics Electrical and Electronics Engineering (JIEEE) 1, no. 1 (April 25, 2020): 1–9. http://dx.doi.org/10.54060/jieee/001.01.004.
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The current monetary system has many issues associated with it like double spending, standard transaction fees, financial crisis, centralized power and private ledgers. Blockchain provides a remedy to all these ills by its basic structure, zero or minimal transaction fees and by providing a public ledger system which is visible to everyone who is the part of blockchain which makes it free from complications like double spending and financial crisis. Blockchain is basically a continuously growing list of records or public distributed ledger system called blocks linked and secured suing cryptography. Each block has multiple transaction details associated with it. It was introduced in the year 2009 by Satoshi Nakamoto, who is believed to be a Japanese man, born in 1974. Given the features and universal nature of the Blockchain, which include decentralized ledger system, proof of work and cryptography, one can appreciate that its implementation could result in far reaching changes in all domains.
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MBONYE, MANASSE R., NICHOLAS BATTISTA, and BENJAMIN FARR. "TIME EVOLUTION OF A NONSINGULAR PRIMORDIAL BLACK HOLE." International Journal of Modern Physics D 21, no. 03 (March 2012): 1250027. http://dx.doi.org/10.1142/s0218271812500277.
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There is growing notion that black holes may not contain curvature singularities (and that indeed nature in general may abhor such spacetime defects). This notion could have implications on our understanding of the evolution of primordial Black holes (PBHs) and possibly on their contribution to cosmic energy. This paper discusses the evolution of a nonsingular black hole (NSBH) based on a recent model [M. R. Mbonye and D. Kazanas, Phys. Rev. D. 72 (2005) 024016]. The model is used to discuss the time evolution of a primordial black hole (PBH), through the early radiation era of the universe to present, under the assumption that PBHs are nonsingular. In particular, we track the evolution of two benchmark PBHs, namely the one radiating up to the end of the cosmic radiation domination era, and the one stopping to radiate currently, and in each case determine some useful features including the initial mass mf and the corresponding time of formation tf. It is found that along the evolutionary history of the universe the distribution of PBH remnant masses (PBH-RM) PBH-RMs follows a power law. We believe such a result can be a useful step in a study to establish current abundance of PBH-MRs.
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Gruzinov, Andrei, Yuri Levin, and Christopher D. Matzner. "Negative dynamical friction on compact objects moving through dense gas." Monthly Notices of the Royal Astronomical Society 492, no. 2 (January 16, 2020): 2755–61. http://dx.doi.org/10.1093/mnras/staa013.
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ABSTRACT An overdense wake is created by a gravitating object moving through a gaseous medium, and this wake pulls back on the object and slows it down. This is conventional dynamical friction in a gaseous medium. We argue that if the object drives a sufficiently powerful outflow, the wake is destroyed and instead an extended underdense region is created behind the object. In this case the overall gravitational force is applied in the direction of the object’s motion, producing a negative dynamical friction (NDF). Black holes in dense gas drive powerful outflows and may experience the NDF, although extensive numerical work is probably needed to demonstrate or refute this conclusively. NDF may be important for stellar-mass black holes and neutron stars inside ‘common envelopes’ in binary systems, for stellar mass black holes inside active galactic nucleus discs, or for massive black holes growing through super-Eddington accretion in early Universe.
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Heckman, Timothy M. "The Co-Evolution of Galaxies and Black Holes: Current Status and Future Prospects." Proceedings of the International Astronomical Union 5, S267 (August 2009): 3–14. http://dx.doi.org/10.1017/s1743921310005508.
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AbstractI begin by summarizing the evidence that there is a close relationship between the evolution of galaxies and supermassive black holes. They evidently share a common fuel source, and feedback from the black hole may be needed to suppress over-cooling in massive galaxies. I then review what we know about the co-evolution of galaxies and black holes in the modern universe (z < 1). We now have a good documentation of which black holes are growing (the lower mass ones), where they are growing (in the less massive early-type galaxies), and how this growth is related in a statistical sense to star formation in the central region of the galaxy. The opportunity in the next decade will be to use the new observatories to undertake ambitious programs of 3-D imaging spectroscopy of the stars and gas in order to understand the actual astrophysical processes that produce the demographics we observe. At high redshift (z > 2), the most massive black holes and the progenitors of the most massive galaxies are forming. Here, we currently have a tantalizing but fragmented view of their co-evolution. In the next decade, the huge increase in sensitivity and discovery power of our observatories will enable us to analyze the large, complete samples we need to achieve robust and clear results.
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Ishibashi, W. "AGN radiative feedback in the early growth of massive black holes." Monthly Notices of the Royal Astronomical Society 489, no. 4 (September 12, 2019): 5225–30. http://dx.doi.org/10.1093/mnras/stz2543.
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ABSTRACT Growing observational evidence confirms the existence of massive black holes ($M_{\rm BH} \sim 10^9 \, \mathrm{M}_{\odot }$), accreting at rates close to the Eddington limit, at very high redshifts ($z \gtrsim 6\!-\!7$) in the early Universe. Recent observations indicate that the host galaxies of the first quasars are chemically evolved systems, containing unexpectedly large amounts of dust. Such a combination of high luminosities and large dust content should form favourable physical conditions for radiative dusty feedback. We explore the impact of the active galactic nucleus (AGN) feedback, driven by radiation pressure on dust, on the early growth of massive black holes. Assuming Eddington-limited exponential black hole growth, we find that the dynamics and energetics of the radiation pressure-driven outflows also follow exponential trends at late times. We obtain modest outflow energetics (with momentum flux $\dot{p} \lesssim L/c$ and kinetic power $\dot{E}_{\rm k} \lesssim 10^{-3} L$), comparable with available observations of quasar-driven outflows at very high redshifts, but significantly lower than typically observed in local quasars and predicted by wind energy-driven models. AGN radiative dusty feedback may thus play an important role in powering galactic outflows in the first quasars in the early Universe.
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Koss, Michael J., Ezequiel Treister, Darshan Kakkad, J. Andrew Casey-Clyde, Taiki Kawamuro, Jonathan Williams, Adi Foord, et al. "UGC 4211: A Confirmed Dual Active Galactic Nucleus in the Local Universe at 230 pc Nuclear Separation." Astrophysical Journal Letters 942, no. 1 (January 1, 2023): L24. http://dx.doi.org/10.3847/2041-8213/aca8f0.
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Abstract We present multiwavelength high-spatial resolution (∼0.″1, 70 pc) observations of UGC 4211 at z = 0.03474, a late-stage major galaxy merger at the closest nuclear separation yet found in near-IR imaging (0.″32, ∼230 pc projected separation). Using Hubble Space Telescope/Space Telescope Imaging Spectrograph, Very Large Telescope/MUSE+AO, Keck/OSIRIS+AO spectroscopy, and the Atacama Large Millimeter/submillimeter Array (ALMA) observations, we show that the spatial distribution, optical and near-infrared emission lines, and millimeter continuum emission are all consistent with both nuclei being powered by accreting supermassive black holes (SMBHs). Our data, combined with common black hole mass prescriptions, suggest that both SMBHs have similar masses, log M BH / M ⊙ ∼ 8.1 (south) and log M BH / M ⊙ ∼ 8.3 (north), respectively. The projected separation of 230 pc (∼6× the black hole sphere of influence) represents the closest-separation dual active galactic nuclei (AGN) studied to date with multiwavelength resolved spectroscopy and shows the potential of nuclear (<50 pc) continuum observations with ALMA to discover hidden growing SMBH pairs. While the exact occurrence rate of close-separation dual AGN is not yet known, it may be surprisingly high, given that UGC 4211 was found within a small, volume-limited sample of nearby hard X-ray detected AGN. Observations of dual SMBH binaries in the subkiloparsec regime at the final stages of dynamical friction provide important constraints for future gravitational wave observatories.
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Cappelluti, Nico, Günther Hasinger та Priyamvada Natarajan. "Exploring the High-redshift PBH-ΛCDM Universe: Early Black Hole Seeding, the First Stars and Cosmic Radiation Backgrounds". Astrophysical Journal 926, № 2 (1 лютого 2022): 205. http://dx.doi.org/10.3847/1538-4357/ac332d.
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Abstract We explore the observational implications of a model in which primordial black holes (PBHs) with a broad birth mass function ranging in mass from a fraction of a solar mass to ∼106 M ⊙, consistent with current observational limits, constitute the dark matter (DM) component in the universe. The formation and evolution of dark matter and baryonic matter in this PBH-Λ cold dark matter (ΛCDM) universe are presented. In this picture, PBH-DM mini-halos collapse earlier than in standard ΛCDM, baryons cool to form stars at z ∼ 15–20, and growing PBHs at these early epochs start to accrete through Bondi capture. The volume emissivity of these sources peaks at z ∼ 20 and rapidly fades at lower redshifts. As a consequence, PBH DM could also provide a channel to make early black hole seeds and naturally account for the origin of an underlying DM halo–host galaxy and central black hole connection that manifests as the M bh–σ correlation. To estimate the luminosity function and contribution to integrated emission power spectrum from these high-redshift PBH-DM halos, we develop a halo occupation distribution model. In addition to tracing the star formation and reionization history, it permits us to evaluate the cosmic infrared and X-ray backgrounds. We find that accretion onto PBHs/active galactic nuclei successfully accounts for the detected backgrounds and their cross-correlation, with the inclusion of an additional IR stellar emission component. Detection of the deep IR source count distribution by the James Webb Space Telescope could reveal the existence of this population of high-redshift star-forming and accreting PBH DM.
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Trebitsch, Maxime, Marta Volonteri, and Yohan Dubois. "Modelling a bright z = 6 galaxy at the faint end of the AGN luminosity function." Monthly Notices of the Royal Astronomical Society 494, no. 3 (April 20, 2020): 3453–63. http://dx.doi.org/10.1093/mnras/staa1012.
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ABSTRACT Recent deep surveys have unravelled a population of faint active galactic nuclei (AGNs) in the high-redshift Universe, leading to various discussions on their nature and their role during the Epoch of Reionization. We use cosmological radiation hydrodynamics simulations of a bright galaxy at z ∼ 6 (${M_\star } \gtrsim 10^{10}\, {\rm M}_{\odot }$) hosting an actively growing supermassive black hole to study the properties of these objects. In particular, we study how the black hole and the galaxy coevolve and what is the relative contribution of the AGNs and of the stellar populations to the luminosity budget of the system. We find that the feedback from the AGN has no strong effect on the properties of the galaxy, and does not increase the total ionizing luminosity of the host. The average escape fraction of our galaxy is around $f_{\rm esc} \sim 5{{\ \rm per\ cent}}$. While our galaxy would be selected as an AGN in deep X-ray surveys, most of the ultraviolet (UV) luminosity is originating from stellar populations. This confirms that there is a transition in the galaxy population from star-forming galaxies to quasar hosts, with bright Lyman-break galaxies with MUV around −22 falling in the overlap region. Our results also suggest that faint AGNs do not contribute significantly to reionizing the Universe.
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Karamanavis, V., E. Angelakis, S. Komossa, I. Myserlis, D. Blinov та J. A. Zensus. "Radio and γ-ray loud narrow-line Seyfert 1 galaxies in the spotlight". Proceedings of the International Astronomical Union 12, S324 (вересень 2016): 184–87. http://dx.doi.org/10.1017/s1743921317001065.
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AbstractNarrow-line Seyfert 1 (NLS1) galaxies provide us with unique insights into the drivers of AGN activity under extreme conditions. Given their low black hole (BH) masses and near-Eddington accretion rates, they represent a class of galaxies with rapidly growing supermassive BHs in the local universe. Here, we present the results from our multi-frequency radio monitoring of a sample of γ-ray loud NLS1 galaxies (γNLS1s), including systems discovered only recently, and featuring both the nearest and the most distant γNLS1s known to date. We also present high-resolution radio imaging of 1H 0323+342, which is remarkable for its spiral or ring-like host. Finally, we present new radio data of the candidate γ-emitting NLS1 galaxy RX J2314.9+2243, characterized by a very steep radio spectrum, unlike other γNLS1s.
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Blandford, Roger, David Meier, and Anthony Readhead. "Relativistic Jets from Active Galactic Nuclei." Annual Review of Astronomy and Astrophysics 57, no. 1 (August 18, 2019): 467–509. http://dx.doi.org/10.1146/annurev-astro-081817-051948.
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The nuclei of most normal galaxies contain supermassive black holes, which can accrete gas through a disk and become active. These active galactic nuclei (AGNs) can form jets that are observed on scales from astronomical units to megaparsecs and from meter wavelengths to TeV energies. High-resolution radio imaging and multiwavelength/messenger campaigns are elucidating the conditions under which this happens. Evidence is presented that: ▪ Relativistic AGN jets are formed when the black hole spins and the the accretion disk is strongly magnetized, perhaps on account of gas accreting at high latitude beyond the black hole sphere of influence. ▪ AGN jets are collimated close to the black hole by magnetic stress associated with a disk wind. ▪ Higher-power jets can emerge from their galactic nuclei in a relativistic, supersonic, and proton-dominated state, and they terminate in strong, hot spot shocks; lower-power jets are degraded to buoyant plumes and bubbles. ▪ Jets may accelerate protons to EeV energies, which contribute to the cosmic ray spectrum and may initiate pair cascades that can efficiently radiate synchrotron γ-rays. ▪ Jets were far more common when the Universe was a few billion years old and black holes and massive galaxies were growing rapidly. ▪ Jets can have a major influence on their environments, stimulating and limiting the growth of galaxies. The observational prospects for securing our understanding of AGN jets are bright.
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Soltani, G. A., and V. I. Malyarovskaya. "Bioresource potential of chaenomeles (Chaenomeles L.) in the humid subtropics of Russia." Bulletin of the State Nikitsky Botanical Gardens, no. 136 (January 8, 2021): 67–77. http://dx.doi.org/10.36305/0513-1634-2020-136-67-77.
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The taxonomic composition of the genus Chaenomeles L. was determined in the conditions of the Sochi Black sea region. Morphological and biological description was made and fruiting was evaluated for 19 taxa. Decorative cultivars Ch. japonica, Ch. speciosa, Ch. × superba, Ch. × vilmoriniana are of interest for cultivation in the humid subtropical zone of Russia. Fruit cultivars are not represented. Ch. sinensis is recommended as a fruit crop of Chaenomeles and a promising form of Ch. × superba has been identified. The cultivar Ch. speciosa ‘ Kermesina ' is universal and recommended for use in both gardening and fruit growing.
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Soltani, G. A., and V. I. Malyarovskaya. "Bioresource potential of chaenomeles (Chaenomeles L.) in the humid subtropics of Russia." Bulletin of the State Nikitsky Botanical Gardens, no. 136 (January 8, 2021): 67–77. http://dx.doi.org/10.36305/0513-1634-2020-136-67-77.
Повний текст джерелаАнотація:
The taxonomic composition of the genus Chaenomeles L. was determined in the conditions of the Sochi Black sea region. Morphological and biological description was made and fruiting was evaluated for 19 taxa. Decorative cultivars Ch. japonica, Ch. speciosa, Ch. × superba, Ch. × vilmoriniana are of interest for cultivation in the humid subtropical zone of Russia. Fruit cultivars are not represented. Ch. sinensis is recommended as a fruit crop of Chaenomeles and a promising form of Ch. × superba has been identified. The cultivar Ch. speciosa ‘ Kermesina ' is universal and recommended for use in both gardening and fruit growing.
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Tao, Han, Christoph Bausch, Craig Richmond, Frederick R. Blattner, and Tyrrell Conway. "Functional Genomics: Expression Analysis ofEscherichia coli Growing on Minimal and Rich Media." Journal of Bacteriology 181, no. 20 (October 15, 1999): 6425–40. http://dx.doi.org/10.1128/jb.181.20.6425-6440.1999.
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ABSTRACT DNA arrays of the entire set of Escherichia coli genes were used to measure the genomic expression patterns of cells growing in late logarithmic phase on minimal glucose medium and on Luria broth containing glucose. Ratios of the transcript levels for all 4,290E. coli protein-encoding genes (cds) were obtained, and analysis of the expression ratio data indicated that the physiological state of the cells under the two growth conditions could be ascertained. The cells in the rich medium grew faster, and expression of the majority of the translation apparatus genes was significantly elevated under this growth condition, consistent with known patterns of growth rate-dependent regulation and increased rate of protein synthesis in rapidly growing cells. The cells grown on minimal medium showed significantly elevated expression of many genes involved in biosynthesis of building blocks, most notably the amino acid biosynthetic pathways. Nearly half of the known RpoS-dependent genes were expressed at significantly higher levels in minimal medium than in rich medium, and rpoS expression was similarly elevated. The role of RpoS regulation in these logarithmic phase cells was suggested by the functions of the RpoS dependent genes that were induced. The hallmark features of E. coli cells growing on glucose minimal medium appeared to be the formation and excretion of acetate, metabolism of the acetate, and protection of the cells from acid stress. A hypothesis invoking RpoS and UspA (universal stress protein, also significantly elevated in minimal glucose medium) as playing a role in coordinating these various aspects and consequences of glucose and acetate metabolism was generated. This experiment demonstrates that genomic expression assays can be applied in a meaningful way to the study of whole-bacterial-cell physiology for the generation of hypotheses and as a guide for more detailed studies of particular genes of interest.
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GRAINGE, PAUL. "TIME's Past in the Present: Nostalgia and the Black and White Image." Journal of American Studies 33, no. 3 (December 1999): 383–92. http://dx.doi.org/10.1017/s0021875899006155.
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In 1995, the Hubble Space Telescope sent back to astronomers at the University of Arizona a series of vivid colour images of the Eagle Nebula, a dense formation of interstellar gas and dust the likes of which cradle newborn stars. As evidence that our perceptual universe, in every sense of the word, is defined by the representational powers of colour technology, the Hubble's “cosmic close-ups” are a clear case in point. Colour has become a standard representational form and hence the visual form. If so, what can be said of the recent popularity and proliferation of the black-and-white image?No self-respecting café-bar or discriminating home, it seems, can now do without a black and white print on the wall. Commercial photography and certain forms of advertising have found a new niche in black and white, and even sepia is staging a come-back. The popularity of the black-and-white image cannot be divorced from the commercial culture in which it circulates; it is a “look” and a marker of taste. Monochrome is a stylistic trend but a revealing one, especially if one considers the growing preoccupation in America with heritage and memory. Both Susan Sontag and Roland Barthes give black and white a status of authenticity judged in relation to past time “properly” captured. For Sontag, monochrome gives an image a sense of age, historical distance, and aura. She writes, “the cold intimacy of color seems to seal off the photograph from patina.” Likewise, Barthes comments on the artifice of colour, how it is a “coating applied later on to the original truth of black and white.” For both critics, monochrome is an aesthetic of the authentic figured around a basic quality of pastness.
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Kauffmann, Guinevere, and Timothy M. Heckman. "The formation of bulges and black holes: lessons from a census of active galaxies in the SDSS." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 363, no. 1828 (January 12, 2005): 621–43. http://dx.doi.org/10.1098/rsta.2004.1516.
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We examine the relationship between galaxies, supermassive black holes and AGN using a sample of 23 000 narrow–emission–line (‘type 2’) active galactic nuclei (AGN) drawn from a sample of 123 000 galaxies from the Sloan Digital Sky Survey. We have studied how AGN host properties compare with those of normal galaxies and how they depend on the luminosity of the active nucleus. We find that AGN reside in massive galaxies and have distributions of sizes and concentrations that are similar to those of the early–type galaxies in our sample. The host galaxies of low–luminosity AGN have stellar populations similar to normal early types. The hosts of highluminosity AGN have much younger mean stellar ages, and a significant fraction have experienced recent starbursts. High–luminosity AGN are also found in lower–density environments. We then use the stellar velocity dispersions of the AGN hosts to estimate black hole masses and their [OIII]λ5007 emission–line luminosities to estimate black hole accretion rates.We find that the volume averaged ratio of star formation to black hole accretion is ∼1000 for the bulge–dominated galaxies in our sample. This is remarkably similar to the observed ratio of stellar mass to black hole mass in nearby bulges. Most of the present–day black hole growth is occurring in black holes with masses less than 3 × 10 7 M ⊙. Our estimated accretion rates imply that low–mass black holes are growing on a time–scale that is comparable with the age of the Universe. Around 50% this growth takes place in AGN that are radiating within a factor of five of the Eddington luminosity. Such systems are rare, making up only 0.2% of the lowmass black hole population at the present day. The remaining growth occurs in lower luminosity AGN. The growth time–scale increases by more than an order of magnitude for the most massive black holes in our sample. We conclude that the evolution of the AGN luminosity function documented in recent optical and X–ray surveys is driven by a decrease in the characteristic mass scale of actively accreting black holes.
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Arca Sedda, Manuel, Gongjie Li, and Bence Kocsis. "Order in the chaos." Astronomy & Astrophysics 650 (June 2021): A189. http://dx.doi.org/10.1051/0004-6361/202038795.
Повний текст джерелаАнотація:
Black hole (BH) triples represent one of the astrophysical pathways for BH mergers in the Universe detectable by LIGO and VIRGO. We study the formation of BH triples via binary–binary encounters in dense clusters, showing that up to two-thirds of the triples formed through this channel are hierarchical, whereas the remaining one-third are in a non-hierarchical, unstable configuration. We built a database of 32 000 N-body simulations to investigate the evolution of BH triples focusing on mildly hierarchical and non-hierarchical unstable configurations. Varying the mutual orbital inclination, the three BH masses and the inner and outer eccentricities, we show that retrograde, nearly planar configurations lead to a significant shrinkage of the inner binary. We find a universal trend of triple systems, namely that they tend to evolve toward prograde configurations and that the orbital flip, driven by the torque exerted on the inner BH binary (BHB) by the outer BH, leads in general to tighter inner orbits. In some cases, the resulting BHB undergoes coalescence within a Hubble time, releasing gravitational waves. A large fraction of merging BHBs with an initial separation of 1 AU enter the 10−3 − 10−1 Hz frequency band with large eccentricities, thus representing potential eccentric LISA sources. Mergers originating from an initially tighter BHB (a ∼ 0.01 AU), instead often have eccentricities above 0.7 in the 1 Hz band. We find that the mass distribution of the mergers in this astrophysical channel maps the original BH binary spectrum. This might have interesting consequences in light of the growing population of BH mergers detected by LIGO and VIRGO, namely that eccentric sources detected in high-frequency detectors are most likely connected with a high-velocity dispersion stellar environment, whereas eccentric sources detected in low-frequency detectors are likely to develop in low-density clusters.
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Strom, Sharon Hartman. "Spiritualist Angels, Masonic Stars, and the Douglass Temple of Universal Brotherhood." California History 95, no. 2 (2018): 2–26. http://dx.doi.org/10.1525/ch.2018.95.2.2.
Повний текст джерелаАнотація:
Between 1900 and 1930, Los Angeles attracted thousands of white and black migrants from the Midwest and the South. Many had attachments to Protestant churches. But they also arrived with commitments to Freemasonry, Spiritualism, and social reform causes. This paper argues that these religionists in Los Angeles covered a broad spectrum of faiths, including Free Thought, innovative versions of Protestantism, and Freemasonry, and that traditional accounts of religion in the city have ignored these aspects of religious life and civic engagement. As World War I ushered in conservatism in every aspect of public life, the Los Angeles Times, the City Council, and the Protestant churches combined in an effort to squash these challenges to orthodoxy. In profiling two prominent Spiritualists, African American George W. Shields and white midwesterner Cynthia Lisetta Vose, this article illustrates the wide ranging civil and religious engagement of two committed Spiritualists. By the end of the 1920s, the fragmentation of Los Angeles neighborhoods and the growing racism of the city had nearly destroyed what had been a vigorous religion and a thriving commitment to progressive reform. Segregated white women's clubs and Freemasonry organizations turned the worship of California into a replacement for older forms of religious practice and civic engagement.
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Marshall, Madeline A., Yueying Ni, Tiziana Di Matteo, J. Stuart B. Wyithe, Stephen Wilkins, Rupert A. C. Croft, and Jussi K. Kuusisto. "The host galaxies of z = 7 quasars: predictions from the BlueTides simulation." Monthly Notices of the Royal Astronomical Society 499, no. 3 (October 5, 2020): 3819–36. http://dx.doi.org/10.1093/mnras/staa2982.
Повний текст джерелаАнотація:
ABSTRACT We examine the properties of the host galaxies of $z=7$ quasars using the large volume, cosmological hydrodynamical simulation BlueTides. We find that the 10 most massive black holes and the 191 quasars in the simulation (with $M_{\textrm{UV,AGN}}\lt M_{\textrm{UV,host}}$) are hosted by massive galaxies with stellar masses $\log (M_\ast /\, {\rm M}_{\odot })=10.8\pm 0.2$, and $10.2\pm 0.4$, which have large star formation rates of $513_{-351}^{+1225}\, {\rm M}_{\odot }/\rm {yr}$ and $191_{-120}^{+288}\, {\rm M}_{\odot }/\rm {yr}$, respectively. The hosts of the most massive black holes and quasars in BlueTides are generally bulge-dominated, with bulge-to-total mass ratio $B/T\simeq 0.85\pm 0.1$; however, their morphologies are not biased relative to the overall $z=7$ galaxy sample. We find that the hosts of the most massive black holes and quasars are compact, with half-mass radii $R_{0.5}=0.41_{-0.14}^{+0.18}$ kpc and $0.40_{-0.09}^{+0.11}$ kpc, respectively; galaxies with similar masses and luminosities have a wider range of sizes with a larger median value, $R_{0.5}=0.71_{-0.25}^{+0.28}$ kpc. We make mock James Webb Space Telescope (JWST) images of these quasars and their host galaxies. We find that distinguishing the host from the quasar emission will be possible but still challenging with JWST, due to the small sizes of quasar hosts. We find that quasar samples are biased tracers of the intrinsic black hole–stellar mass relation, following a relation that is 0.2 dex higher than that of the full galaxy sample. Finally, we find that the most massive black holes and quasars are more likely to be found in denser environments than the typical $M_{\textrm{BH}}\gt 10^{6.5}\, {\rm M}_{\odot }$ black hole, indicating that minor mergers play at least some role in growing black holes in the early Universe.
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Lawrence Johnson, Jarrett, and Phoebe R. Upton Sanderbeck. "A Simple Condition for Sustained Super-Eddington Black Hole Growth." Astrophysical Journal 934, no. 1 (July 1, 2022): 58. http://dx.doi.org/10.3847/1538-4357/ac7b81.
Повний текст джерелаАнотація:
Abstract One of the most pressing questions in cosmology is how the black holes (BHs) powering quasars at high redshift grow to supermassive scales within a billion years of the Big Bang. Here we show that sustained super-Eddington accretion can be achieved for BHs with Eddington fractions f Edd ≳ 2/ϵ, where ϵ is the efficiency with which radiation is generated in the accretion process. In this regime, the radiation carries too little momentum to halt the accretion flow and the infalling gas traps the radiation. The BH growth then proceeds unimpeded until the gas supply is exhausted, in contrast to accretion at lower rates, which is limited by the radiation generated in the accretion process. The large gas supply available in massive high-redshift quasar host galaxies may be readily accreted onto seed BHs via this supply-limited mode of accretion, providing an explanation for how such supermassive BHs are assembled in the early universe. This sustained super-Eddington growth may also explain the short lifetimes inferred for the H ii regions surrounding high-redshift quasars, if the bulk of the BH growth occurs without the associated radiation escaping to ionize the intergalactic medium. It furthermore implies that a population of obscured rapidly growing BHs may be difficult to detect, perhaps explaining why so few quasars with Eddington fractions higher than a few have been observed. Finally, this simple condition for sustained super-Eddington growth can easily be implemented in cosmological simulations that can be used to assess in which environments it occurs.
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Kim, Yongjung, Myungshin Im, Yiseul Jeon, Minjin Kim, Minhee Hyun, Dohyeong Kim, Jae-Woo Kim, et al. "The Infrared Medium-deep Survey. IV. The Low Eddington Ratio of A Faint Quasar atz∼ 6: Not Every Supermassive Black Hole is Growing Fast in the Early Universe." Astrophysical Journal 855, no. 2 (March 16, 2018): 138. http://dx.doi.org/10.3847/1538-4357/aaadae.
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Kifle, Desalegn Woldeyohannes, Javier Sotillo, Mark S. Pearson, and Alex Loukas. "Extracellular vesicles as a target for the development of anti-helminth vaccines." Emerging Topics in Life Sciences 1, no. 6 (December 22, 2017): 659–65. http://dx.doi.org/10.1042/etls20170095.
Повний текст джерелаАнотація:
There is a rapidly growing body of evidence that production of extracellular vesicles (EVs) is a universal feature of cellular life. More recently, EVs have been identified in a broad range of both unicellular and multicellular parasites where they play roles in parasite–parasite intercommunication as well as parasite–host interactions. Parasitic helminth-derived EVs traverse host target cell membranes whereupon they offload their molecular cargo — proteins, lipids, and genetic information such as mRNAs and miRNAs — which are thought to hijack the target cell and modulate its gene expression to promote parasite survival. As such, EVs represent a novel mechanism of intercellular communication that could be targeted for vaccine-mediated interruption, given the abundance of surface antigens expressed on helminth EVs, and the ability of antibodies to block their uptake by target cells. In this Perspective article, we review recent developments in the field of helminth-derived EVs and highlight their roles in helminth vaccine discovery and development.
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Boughammoura, Radhouane, Mohamed Nazih Omri, and Lobna Hlaoua. "Information Retrieval from Deep Web Based on Visual Query Interpretation." International Journal of Information Retrieval Research 2, no. 4 (October 2012): 45–59. http://dx.doi.org/10.4018/ijirr.2012100104.
Повний текст джерелаАнотація:
Deep Web is growing rapidly. More than 90% of relevant information in web comes from deep Web. Users are usually interested by products which satisfy their needs at the best prices and quality of service .Hence, user’s needs concerns not only one service but many competitive services at the same time. However, for commercial reasons, there is no way to compare all web services products. Each web service is a black box which accepts queries through its own query interface and returns results. As consequence, users ask separately different web services and spend a lot of time comparing products in order to find the best one. This is a burden for novice users. In this paper, the authors propose a new approach which integrates query interfaces of many web services into one universal web service. The new interface describes visually the universal query and is used to ask many web services at the same time. The authors have evaluated their approach on standard datasets and have proved good performances.
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Inayoshi, Kohei, Riouhei Nakatani, Daisuke Toyouchi, Takashi Hosokawa, Rolf Kuiper, and Masafusa Onoue. "Rapid Growth of Seed Black Holes during Early Bulge Formation." Astrophysical Journal 927, no. 2 (March 1, 2022): 237. http://dx.doi.org/10.3847/1538-4357/ac4751.
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Abstract We study the early growth of massive seed black holes (BHs) via accretion in protogalactic nuclei where the stellar bulge component is assembled, performing axisymmetric two-dimensional radiation hydrodynamical simulations. We find that when a seed BH with M • ∼ 105 M ⊙ is embedded in dense metal-poor gas (Z = 0.01 Z ⊙) with a density of ≳ 100 cm−3 and bulge stars with a total mass of M ⋆ ≳ 100 M •, a massive gaseous disk feeds the BH efficiently at rates of ≳ 0.3–1 M ⊙ yr−1, and the BH mass increases nearly tenfold within ∼2 Myr. This rapid accretion phase lasts until a good fraction of the gas bounded within the bulge accretes onto the BH, although the feeding rate is regulated owing to strong outflows driven by ionizing radiation emitted from the accreting BH. The transient growing mode can be triggered for seed BHs formed in massive dark-matter halos with masses of ≳ 109 M ⊙ at z ∼ 15–20 (the virial temperature is T vir ≃ 105 K). The host halos are heavier and rarer than those of typical first galaxies, but are more likely to end up in quasar hosts by z ≃ 6. This mechanism naturally yields a mass ratio of M •/M ⋆ > 0.01 higher than the value seen in the local universe. The existence of such overmassive BHs provides us with a unique opportunity to detect highly accreting seed BHs at z ∼ 15 with AB magnitude of m AB ∼ 26–29 mag at 2 μm (rest frame 10 eV) by the upcoming observations by the James Webb Space Telescope and Nancy Grace Roman Space Telescope.
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Stratta, Giulia, and Francesco Pannarale. "Neutron Star Binary Mergers: The Legacy of GW170817 and Future Prospects." Universe 8, no. 9 (September 2, 2022): 459. http://dx.doi.org/10.3390/universe8090459.
Повний текст джерелаАнотація:
In 2015, the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) and Advanced Virgo began observing the Universe in a revolutionary way. Gravitational waves from cosmic sources were detected for the first time, confirming their existence predicted almost one century before, and also directly revealing the existence of black holes in binary systems and characterizing their properties. In 2017, a new revolution was achieved with the first observation of a binary neutron star merger, GW170817, and its associated electromagnetic emission. The combination of the information from gravitational-wave and electromagnetic radiation produced a wealth of results, still growing, spectacularly demonstrating the power of the newly born field of gravitational-wave Multi Messenger Astrophysics. We discuss the discovery of GW170817 in the context of the achievements it brought to Gamma-Ray Burst astrophysics, and we also provide a few examples of advancements in fundamental physics and cosmology. The detection rates of binary neutron star mergers expected in the next decade for third generation gravitational-wave interferometers will open the new perspective of a statistical approach to the study of these multi-messenger sources.
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Wolf, Christian, Wei Jeat Hon, Fuyan Bian, Christopher A. Onken, Noura Alonzi, Michael A. Bessell, Zefeng Li, Brian P. Schmidt, and Patrick Tisserand. "Ultra-luminous quasars at redshift z > 4.5 from SkyMapper." Monthly Notices of the Royal Astronomical Society 491, no. 2 (October 21, 2019): 1970–79. http://dx.doi.org/10.1093/mnras/stz2955.
Повний текст джерелаАнотація:
ABSTRACT The most luminous quasars at high-redshift harbour the fastest growing and most massive black holes in the early Universe. They are exceedingly rare and hard to find. Here, we present our search for the most luminous quasars in the redshift range from z = 4.5 to 5 using data from SkyMapper, Gaia, and WISE. We use colours to select likely high-redshift quasars and reduce the stellar contamination of the candidate set with parallax and proper motion data. In ∼12 500 deg2 of Southern sky, we find 92 candidates brighter than Rp = 18.2. Spectroscopic follow-up has revealed 21 quasars at z ≥ 4 (16 of which are within z = [4.5, 5]), as well as several red quasars, Broad-Absorption-Line (BAL) quasars and objects with unusual spectra, which we tentatively label OFeLoBALQSOs at redshifts of z ≈ 1 to 2. This work lifts the number of known bright z ≥ 4.5 quasars in the Southern hemisphere from 10 to 26 and brings the total number of quasars known at Rp < 18.2 and z ≥ 4.5 to 42.
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TALANCHUK, Dmytro, and Oleksandr MARKOVETS. "DEVELOPMENT OF A SET OF MEASURES TO PROMOTE THE INSTAGRAM PAGE." Herald of Khmelnytskyi National University 305, no. 1 (February 23, 2022): 90–95. http://dx.doi.org/10.31891/2307-5732-2022-305-1-90-95.
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The article presents the results of a study of the development of the page on the social network Instagram. A review of scientific sources that cover data on the promotion of profiles on social networks. To achieve this goal, a universal flowchart of the algorithm of actions was created, which will help to get reactions to the distributed content. The limits of interaction with the content that will help to avoid blocking the page are highlighted and the statistics of the page based on which the research of the social network Instagram was conducted are shown. The growing popularity of the social network Instagram encourages the study of methods to promote the profile This study contains information about methods of promoting the page that does not require money. The flowchart will help start-up bloggers and small businesses that do not have the funds to advertise to gain additional reach of the target audience. This block diagram is universal and does not require special topics of the pages. The shown statistics will prove the efficiency of the created block diagram of the page development algorithm. With the help of the flowchart, users will be able to receive additional hundreds, sometimes thousands, of additional target audience reach and content interactions. A study was conducted to determine the best time to publish content. Properly chosen time increases the chances of greater coverage of people on the social network. To determine the time, a foreign study was analyzed and a new one was conducted based on its own Instagram page and KeyHole resource. The article describes the effectiveness and importance of using correct and thematic hashtags. The use of hashtags, as well as other described methods, will help increase the reach of the target audience. The statistics show the effectiveness of this method of popularizing the page and describe the optimal number of hashtags per post.
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Shakina, T. N. "Adaptation experience of some ornamental and fruit-berry plantlets to ex vitro conditions in the training and science center “Botanical garden” of Saratov State University n. a. N. G. Chernyshevsky." Проблемы ботаники Южной Сибири и Монголии 19, no. 1 (June 8, 2020): 315–20. http://dx.doi.org/10.14258/pbssm.2020063.
Повний текст джерелаАнотація:
One of the quickways of vegetative plant reproduction is micropropagation. Receiving high results usingthis method is significantly limited by one of the most important stages – adaptation of plantlets to growing under ex vitroconditions, which completes the whole process of reproduction in vitro. To date, there are no universal technologies foradaptation plantlets to non-sterile conditions, which would suit all crops, determine the optimal humidity conditions, substrate, temperature and lighting. The article presents preliminary results of the study of the plantlets adaptive potential fora number of ornamental and fruit-berry crops in non-sterile conditions. The objects of the study were: Cotinus coggygria'Royal Purple'; Syringa vulgaris 'M-me Casimir Perier', 'А. Gromov', 'Sensation'; Pentaphylloides fruticosa L.; Weigelahybrida 'Eva Rathke', 'Candida'; Sorbus aucuparia 'Granatnaya'; Ribes nigrum 'Black Pearl', ' Bagheera', 'Elvesta', 'LittlePrince', 'Wonderful moment', 'Charovnica', 'Zusha', 'Tamerlan', 'Dachnica', 'Dessertnay Olkhina', 'Zagadka'; Lonicera edulis 'Gzhelka', 'Kamchadalka', 'Lazurnay', Moscowskay''.
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Bibossinov, Assylkhan, Denis Yurin, and Chingis Omarov. "Numerical Studies of Astrophysical Objects at Fesenkov Astrophysical Institute (FAI)." Communications of the Byurakan Astrophysical Observatory 2, no. 1 (2018): 124–34. http://dx.doi.org/10.52526/25792776-2018.2.1-124.
Повний текст джерелаАнотація:
Numerical studies of astrophysical objects are a relatively new direction in Fesenkov Astrophysical Institute (FAI) and is mainly represented by the Laboratory of Cosmology, Stellar Dynamics and Computational Astrophysics. The lab seeks to understand the evolution of gravitating systems at various scales – from star clusters to galaxies to large-scale structure of the universe as a whole, and tackles these problems both through analytical methods and through numerical simulations. The particular focus is on numerical simulations of star clusters, especially those found in active galactic nuclei – this is a topic of oldestablished collaboration with colleagues from Astronomisches Rechen-Institut (Heidelberg) and National Astronomical Observatories of China (Beijing). The prominent example is STARDISK project dedicated to the numerical research of active galactic nuclei as multicomponent systems composed of compact stellar cluster, gaseous accretion disk and a supermassive black hole. It is demonstrated that an accretion disk can noticeably decelerate stars and thus enhance the accretion rate onto the black hole. In 2013 FAI hosted the MODEST-13 International Workshop dedicated to modeling of star clusters. Recently a new project has been approved aimed at construction of triaxial equilibrium N-body systems that can be of great help in various numerical experiments with disk galaxies. There are also long standing plans to perform cosmological simulations of large scale structures to test a new approach to dark matter and energy actively developed at FAI. For numerical calculations, FAI has a small, but growing computer cluster consisting of several high-performance computing servers equipped with computational GPU cards.
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Barbosa, Bárbara Ferraz, Camila Bordignon Barbosa, Debora Neves de Santana, Cosme Andrade de Almeida, and Vivian Miranda Lago. "Black and brown women: vulnerabilities occurred from 2010 to 2018 in the extreme southern of Bahia." Uningá Review Journal 37, no. 1 (October 28, 2022): eURJ4336. http://dx.doi.org/10.46311/2178-2571.37.eurj4336.
Повний текст джерелаАнотація:
Violence alters our society in countless ways, being disproportionate in relation to women, especially blacks and browns in situations of vulnerability, which leaves them prone to traces that influence their daily lives. The objective of this theme was to analyze the prevalence of domestic, sexual and / or other conditional violences in black and brown women in the period from 2010 to 2018, in the extreme south of Bahia. For the concreteness of this research an epidemiological, cross-sectional and descriptive approach was the chosen methodology, which was enabled by the secondary information provided by the Ministry of Health in the DATASUS database, evaluating the state and the macro-region of the Far South, correlating with the number of psychological / moral violence in both. Upon entering the questions that guided this study, it was noticed that in view of the universe researched, the results show a growing number of cases, from 873 cases in 2010 to 25,872 in 2018 in the state, when the macro-region was analyzed, there were a total of 1,751 cases, as for phycological/ moral violence, the maximum peak occurred in 2018, in both regions; the study shows an exorbitant increase in physical abuse in relation to black and brown women at risk in Bahia, especially in the macro-region. It is concluded that it is necessary to increase measures aimed at providing greater protection and care for the victims, since the home is "the most dangerous place for these women", which often culminates in long-term violence.
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Paz, Moria. "The Incomplete Right to Freedom of Movement." AJIL Unbound 111 (2017): 514–18. http://dx.doi.org/10.1017/aju.2018.23.
Повний текст джерелаАнотація:
We live now in the midst of a massive global crisis of mobility. An ever-growing population finds itself refugees displaced from the legitimate jurisdiction of any territorial state. In the face of this pressing emergency, influential voices argue that international human rights law should be placed “at the center” of international efforts to meet this challenge. But today's calamity is set against the backdrop of a universal human rights regime that is not only thin but, more importantly, incomplete. When it comes to cross-border mobility, human rights law ensures that states allow individuals to leave their state, but alas does not require that any other state let them enter and remain. Such entry and residence rights are required only for a country's own nationals (however nationality is defined). And so, many refugees who have exercised their human right to exit come up against a functional block to mobility: they have no place to stop moving. Some of them may nonetheless find a state willing to take them in. In that case, they may enjoy meaningful protection, but this protection exists only by virtue of a state's domestic policies and has little to do with international human rights.
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Melia, Fulvio. "J1342+0928 supports the timeline in the Rh = ct cosmology." Astronomy & Astrophysics 615 (July 2018): A113. http://dx.doi.org/10.1051/0004-6361/201832752.
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Aims. The discovery of quasar J1342+0928 (z = 7.54) reinforces the time compression problem associated with the premature formation of structure in Λ cold dark matter (ΛCDM). Adopting the Planck parameters, we see this quasar barely 690 Myr after the big bang, no more than several hundred Myr after the transition from Pop III to Pop II star formation. Yet conventional astrophysics would tell us that a 10 M⊙ seed, created by a Pop II/III supernova, should have taken at least 820 Myr to grow via Eddington-limited accretion. This failure by ΛCDM constitutes one of its most serious challenges, requiring exotic “fixes”, such as anomalously high accretion rates, or the creation of enormously massive (~ 105 M⊙) seeds, neither of which is ever seen in the local Universe, or anywhere else for that matter. Indeed, to emphasize this point, J1342+0928 is seen to be accreting at about the Eddington rate, negating any attempt at explaining its unusually high mass due to such exotic means. In this paper, we aim to demonstrate that the discovery of this quasar instead strongly confirms the cosmological timeline predicted by the Rh = ct Universe. Methods. We assume conventional Eddington-limited accretion and the time versus redshift relation in this model to calculate when a seed needed to start growing as a function of its mass in order to reach the observed mass of J1342+0928 at z = 7.54. Results. Contrary to the tension created in the standard model by the appearance of this massive quasar so early in its history, we find that in the Rh = ct cosmology, a 10 M⊙ seed at z ~ 15 (the start of the Epoch of Reionization at t ~ 878 Myr) would have easily grown into an 8 × 108 M⊙ black hole at z = 7.54 (t ~ 1.65 Gyr) via conventional Eddington-limited accretion.
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Akhtar, Najma, Rajiv K. Gupta, Kiran Bala, Vijay Mengi, and Chandni Gupta. "Menopausal symptoms in rural middle aged women: a community based cross sectional study." International Journal of Reproduction, Contraception, Obstetrics and Gynecology 7, no. 9 (August 27, 2018): 3678. http://dx.doi.org/10.18203/2320-1770.ijrcog20183776.
Повний текст джерелаАнотація:
Background: Menopause poses a big challenge to the healthy aging of a woman. With growing emphasis on universal health coverage and improving quality of life, it is the need of hour to address the issues population of postmenopausal women to enhance our understanding of women’s experiences during menopause.Methods: This cross-sectional study was conducted using non-probability purposive sampling and house-to-house visit in randomly selected villages falling under rural Health Block Kot-Bhalwal. 245 postmenopausal women were interviewed in accordance with pretested questionnaire consisting of Sociodemographic data and Greene Climacteric Scale.Results: Muscle and joint pains was the most common complaint (89.0%), followed by feeling tired or lacking in energy (87.4%), difficulty in sleeping (82.5%) and difficulty in concentrating (80.4%). Nearly three-fourth of the study participants reported to be suffering from Irritability (77.6%), feeling tense/nervous (77.5%), Headaches (76.7%), loss of interest in most things (75.9%), feeling unhappy or depressed (74.29%), sweating at night (73.47%), attacks of anxiety, panic (73.5%), pressure or tightness in head (72.6%), and feeling dizzy or faint (71.8%).Conclusions: A higher prevalence of menopausal symptoms was found. However, more research studies are needed to determine rural urban differences in prevalence and severity of the symptoms using a standardized tool on a larger sample in the community setting.
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Cornish, Flora. "Communicative generalisation: Dialogical means of advancing knowledge through a case study of an ‘unprecedented’ disaster." Culture & Psychology 26, no. 1 (January 24, 2020): 78–95. http://dx.doi.org/10.1177/1354067x19894930.
Повний текст джерелаАнотація:
In the interest of learning from a unique and devastating disaster, this paper develops a conceptualisation of generalisation as a communicative process. Growing from the author’s experience of conducting and communicating an ethnographic case study of the community response to the Grenfell Tower disaster, a tower block fire which traumatised a West London community, and has been widely labelled an ‘unprecedented’ event, the paper considers ways of developing knowledge with wider application from this unique case. ‘Communicative generalisation’ is concerned with the significance of knowledge to epistemic communities rather than abstract universal truth. Four modes of communicative generalisation are explored. By elaborating the multi-perspectival nature of a case and its relation to its context, case studies may enrich readers’ generalised other. Case studies may address an epistemic community by problematising a taken-for-granted situation or theory. A case study can extend the situations to which it may transfer by multiplying its audiences, and thus forcing its authors to take multiple perspectives. It can also extend its meaningfulness by multiplying speakers, facilitating expressions of diverse perspectives on the case. ‘Communicative generalisation’ distributes the agency of generalisation among authors, cases and audiences. This redistribution has implications for the politics and temporality of generalisation.
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Liu, Teng Jiao, Zhi Ming Liu, and Wei Qi Sun. "Research of Cover and Management Factor in the Model of the Revised Universal Soil Loss Equation of Black Earth Erosion in Northeastern Part of China." Applied Mechanics and Materials 209-211 (October 2012): 1190–93. http://dx.doi.org/10.4028/www.scientific.net/amm.209-211.1190.
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Solid vegetation roots may lead to the strong grip on the soil, thus they have a lot of positive effects, such as reducing both the rainfall kinetic energy and the amount of soil erosion, strengthening soil conservation and soil-reinforcement. Therefore, vegetation is a decisive factor in preventing soil erosion. Cover-management-C-factor is an important influential factor in The Universal Soil Loss Equation (USLE), determined mainly by such factors as vegetation coverage, situation of land utilization, productivity level, crop cultivation order, crop growing sequence, etc. So the value of Cover-management-C-factor is often difficult to estimate. Based on GIS technology, vegetation cover parameters drawn by SPOT statistics as well as field study, this research reveals the different land use types in the northeastern area of China so that the C-value of that area can be calculated through both formula and experimental assignment. Furthermore, by comparison of the two results, the C-value will be proved more precise and practical and thus its impact on soil erosion will provide more scientific basis for us.
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Vafin, Il'shat, and Radik Safin. "Evaluation of the effectiveness of the use of physiologically active substances and fertilizers on winter wheat." Agrobiotechnologies and digital farming 1, no. 2 (July 27, 2022): 12–16. http://dx.doi.org/10.12737/2782-490x-2022-12-16.
Повний текст джерелаАнотація:
The studies were carried out on winter wheat varieties Kazanskaya 560 for three years, of which two (2018, 2019) were characterized by periodically dry phenomena during the spring-summer growing season and one (2020) was with normal moisture. The aim of the work was to study the effectiveness of the use of the Melafen growth stimulator on winter wheat in the autumn period and double foliar feeding in the spring-summer period with the complex liquid fertilizer Metallocene Universal. The studies were carried out on gray forest soil using the recommended agricultural technology for the cultivation of winter wheat. In the course of the research, the influence of the studied preparations and their combinations on the biometric parameters of plants, the development of diseases, the productivity and quality characteristics of winter wheat seeds was studied. It was found that when using the autumn treatment of crops with the growth stimulator Melafen, there was an increase of 17.8% in plant density for harvesting, which is due to the positive effect of the stimulator on the overwintering of winter wheat. As a result, the yield in this variant increased by 0.48 t/ha. The use of only top dressing with Metallocene Universal led to an increase in the number of grains per spike and an increase in yield by 0.43 t/ha. The alternation of treatments (autumn spraying by Melafen; spring-summer spraying by Metalocene Universal) contributed to an increase in the number of grains per ear, an increase in the mass of 1000 seeds, which led to a significant (0.9 t/ha) increase in the yield of winter wheat. Double foliar feeding with Metallocene Universal contributes to some reduction in the infection of an ear of winter wheat with stagonospora blotch. In all experimental variants, there was no decrease in damage to the ear by "black head molds". The studied variants did not have a significant positive effect on the accumulation of protein in wheat grain.
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Aniskin, Vladimir Nicolaevich, and Elena Nicolaevna Ryabinova. "Training and educational problems solving in the study of mathematics at university." Samara Journal of Science 5, no. 3 (September 1, 2016): 141–47. http://dx.doi.org/10.17816/snv20163301.
Повний текст джерелаАнотація:
The analysis of federal state educational standards for all steps of existing educational system shows that meta-subject approach in learning and bringing up activity is becoming more urgent. Orientation to the key strategic priority of continuous education such as bringing up activity and forming the ability to study are also urgent. The main types of universal studying activities are analyzed: personal, subject, meta-subject results; usage of learning activity matrix during the process of study. Federal State Educational Standard of basic common education sets the demands to personal, meta-subject and subject results of learning after basic educational program of secondary education. So, according to the succession principle we should develop the competence of the students following these three directions transforming them into educational environment of the university. Thus, meta-subject competence should include ability to use intersubject definitions and universal learning activities performing them at learning, knowledge and social practice. The achievement of meta-subject results is connected with the nature of universal activity. The basis of nature-coordinated education should lie in basic values - and the most important is morality which is formed from the human nature. That is why the standards of the second generation formulate four blocks of universal learning activities: personal, regulative, common knowledge and communicative. According to their nature meta-subject activities are functional-oriented ones and they form the psychological basis and determining condition of subject task solution success. Meta-subject competence development supposes various forms of studying process organization. One of such organization forms can be the business game which can be used as the means of diagnosis and forecast of personal behavior in various situations. Project technology is also aimed to develop wide range of competence and creative abilities and that is why it suggests the integrity of research, searching, problem solving and comparison methods. It has been shown that nowadays the role of each course in meta-subject competence development has been growing rapidly.
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Ramdial, H. A., and S. N. Rampersad. "First Report of Fusarium solani Causing Fruit Rot of Sweet Pepper in Trinidad." Plant Disease 94, no. 11 (November 2010): 1375. http://dx.doi.org/10.1094/pdis-06-10-0433.
Повний текст джерелаАнотація:
In Trinidad, sweet pepper (Capsicum annuum L.) is an important crop that is produced for local markets and regional export. From February to April 2010, severe fruit rot was observed in 9 of 11 commercial fields located in North Trinidad in the major production areas of North and South Aranguez. All fields were in the late harvesting stage and the most commonly grown cultivars were Aristotle and Canape. Disease incidence for each field was estimated to be 80% with a yield loss of 40 to 60%. Symptoms appeared on mature red fruits but growers reported that disease can also occur on green fruit. Symptoms began as soft lesions that turned dark brown to black. Lesions usually originated at the calyx end of the fruit and extended down the sides. Fruits were surface sterilized by rinsing with 70% ethanol for 2 min, followed by three rinses with sterile distilled water. Two 4-mm3 blocks of tissue from the opposite sides of fruit lesions were transferred to water agar and incubated for 5 to 7 days at 25 ± 1°C. A 4-mm3 agar block consisting of the leading mycelial edge was then transferred to potato dextrose agar (PDA) and incubated under the same conditions. Colonies on PDA were fast growing with white, fluffy, aerial mycelia; hyphae were septate and hyaline; conidiophores were unbranched; microconidia were abundant, thin walled, hyaline, ovoid, one to two celled, and measured 6 to 10 × 2 to 4 μm. Macroconidia were hyaline, three to four celled, curved, thick walled, and measured 20 to 30 × 4 to 6 μm. PCR amplification was carried out utilizing universal primers ITS4/5 and translation elongation factor primers EF1/2 (2). Sequence comparisons of the internal transcribed spacer (ITS) region (HM157262) and EF-1α gene (HQ014854) with cognate sequences available in GenBank and the FUSARIUM-ID databases revealed 100 and 99.6% sequence identity, respectively, to Fusarium solani (Mart.) Sacc. Pathogenicity tests were conducted by drop inoculating 10-μl of spore suspension (106 spores/ml) of each of four isolates on wounded and unwounded sites of mature sweet pepper fruits (five per isolate of cvs. Aristotle, Canape, Century, Destra, and Paladin). Control fruits were inoculated with sterile distilled water. Inoculated fruits were kept at 25 ± 1°C in loosely sealed plastic containers and monitored for the onset of symptoms for 6 days. The experiment was conducted twice. Lesions (8.0 to 15.2 mm in diameter) developed on wounded fruit of Aristotle, Canape, and Century. No symptoms were seen on Destra, Paladin, or the water controls. No symptoms developed on nonwounded fruits. Koch's postulates were fulfilled by reisolating the pathogen from infected tissues. Fruit rot caused by F. solani has been reported to be a serious constraint to sweet pepper production in Canada (4), the United Kingdom (1), and New Zealand (3). To our knowledge, this is the first report of Fusarium fruit rot of sweet pepper in Trinidad. References: (1) J. T. Fletcher. Plant Pathol. 43:225, 1994. (2) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (3) J. L. Tyson. Aust. Plant Pathol. 30:375, 2001. (4) R. Utkhede and S. Mathur. Plant Dis. 87:100, 2003.
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Timoschuk, Nina Alexandrovna. "Meta-subject competence development of future bachelors and specialists." Samara Journal of Science 5, no. 2 (June 1, 2016): 189–94. http://dx.doi.org/10.17816/snv20162312.
Повний текст джерелаАнотація:
Federal State Educational Standard of basic common education sets the demands to personal, meta-subject and subject results of learning after basic educational program of common education. So, according to the succession principle we should develop the competence of the students following these three directions transforming them into educational environment of the university. Thus, meta-subject competence should include ability to use intersubject definitions and universal learning activities performing them at learning, knowledge and social practice. The achievement of meta-subject results is connected with the nature of universal activity. The basis of nature-coordinated education should be basic values - and the most important is morality which is formed from the human nature. That is why the standards of the second generation formulate four blocks of universal learning activities: personal, regulative, common knowledge and communicative. According to their nature meta-subject activities are functional-oriented ones and they form the psychological basis and determine condition of the success of subject task solution. Meta-subject competence development supposes various forms of studying process organization. Problem learning implies active interrelation of the subjects of learning process allowing to form such students categories as readiness, activeness, ability to appreciate which are the key ones for the term competence. One of such organization forms can be the business game which can be used as the means of diagnosis and forecast of personal behavior in various situations. Project technology is also aimed to develop wide range of competence and creative abilities and that is why it suggests the integrity of research, searching, problem solving and comparison methods. It has been shown that nowadays the role of each discipline in meta-subject competence development has been growing rapidly.
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Traburova, E. A., T. A. Rozhmina, and I. A. Andreeva. "Screening of flax gene pool samples by fiber yield and their adaptability to the conditions of the Central Non-Black Earth Region." Agricultural Science Euro-North-East 21, no. 6 (December 13, 2020): 688–96. http://dx.doi.org/10.30766/2072-9081.2020.21.6.688-696.
Повний текст джерелаАнотація:
The research was carried out in 2017-2019 in the conditions of the Smolensk region on sod-podzolic medium loamy slightly acidic soil. The study included 25 varieties and lines of fiber flax of domestic and foreign selection. The mid-ripening variety Impuls (Russia) was used as a standard, whose yield, depending on the test year, was 1.07...1.29 t/ha. As shown by the calculations of the index of environmental conditions, the most favorable conditions for fiber flax developed in 2018 (Ij = +0.46), and stress conditions, caused by excessive moisture during the critical period of plant growth and development (GTC = 1.7), in 2017 (Ij = -0.55). On average, over the years of research, the yield of fiber, depending on the genotype, varied in the range of 1.00...1.97 t/ha. The highest yield on average for three years of testing (1.78...1.97 t/ha) and average yield in contrasting conditions were characteristic of the varieties Cesar, Sinel, Dobrinya (Russia), Marylin (Holland), Andrea, Altea (France). Under favorable weather conditions (2018), a high potential for the yield of flax fiber compared to the average value (121.5...133.3 %) was obtained in the varieties Cesar, Dobrinya, Sinel (Russia), Belita (Belarus), Andrea, Altea (France), Marylin (Holland). Under stressful conditions (2017), high adaptability was found in the samples of the Russian selection Cesar (173.4 %), Sinel (168.0 %), Dobrinya (151.1 %), Tost 3 (128.7 %), Alfa, Universal (127.7 %). The varieties Surskiy (bi = 2.2), Belita (Belarus), l. 323-02 (Russia), Marylin (Holland) − 1.7, Alexandrit (Russia), Andrea (France) – 1.5. Were characterized by high responsiveness to cultivation conditions (bi> 1). Russian varieties with a relatively stable yield: Cesar, Sinel – 0.7, Alpha – 0.6, Lider, Smolich, Tost 3, Universal – 0.5, Impuls – 0,2 did not show reaction to changes in growing conditions (bi <1). Thus, the domestic varieties Cesar, Dobrinya and Sinel have the highest yield of flax fiber and adaptability to the soil and climatic conditions of the Central Non–Black Earth Region. Expansion of fiber flax acreage under these varieties will provide strengthening of the domestic raw material base.
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Khalesi, Rayhaneh, Mahdi Abbasi, Zahra Shahidi, Masoumeh Hasani Tabatabaei, and Zohreh Moradi. "Interfacial Fracture Toughness Comparison of Three Indirect Resin Composites to Dentin and Polyether Ether Ketone Polymer." European Journal of Dentistry 14, no. 03 (July 2020): 456–61. http://dx.doi.org/10.1055/s-0040-1713309.
Повний текст джерелаАнотація:
Abstract Objectives Advances in laboratory composites and their high wear resistance and fracture toughness have resulted in their growing popularity and increasing use for dental restorations. This study sought to assess the fracture toughness of three indirect composites bonded to dental substrate and polyether ether ketone (PEEK) polymer. Materials and Methods This in vitro study was conducted on two groups of dental and polymer substrates. Each substrate was bonded to three indirect composite resins. Sixty blocks (3 × 3 × 12 mm) were made of sound bovine anterior teeth and PEEK polymer. Sixty blocks (3 × 3 × 12 mm) were fabricated of CRIOS (Coltene, Germany), high impact polymer composite (HIPC; Bredent, Germany), and GRADIA (Indirect; GC, Japan) composite resins. Composites were bonded to dentin using Panavia F 2.0 (Kuraray, Japan). For bonding to PEEK, Combo.lign (Bredent) and Visio.Link (Bredent) luting cements were used. In all samples, a single-edge notch was created by a no. 11 surgical blade at the interface. The samples were subjected to 3,500 thermal cycles, and their fracture toughness was measured in a universal testing machine (Zwick/Roell, Germany) by application of four-point flexural load. Statistical Analysis Data were analyzed using one-way analysis of variance, Kruskal–Wallis. Results The fracture toughness of CRIOS–PEEK interface was significantly higher than HIPC–PEEK. The fracture toughness of GRADIA–PEEK was not significantly different from that of HIPC and CRIOS. The fracture toughness of GRADIA–dentin was significantly higher than HIPC–dentin. Conclusion Considering the limitations of this study, GRADIA has the highest bond strength to dentin, while CRIOS shows the highest bond strength to PEEK.
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Helton, Jakob M., Sean D. Johnson, Jenny E. Greene, and Hsiao-Wen Chen. "Discovery and origins of giant optical nebulae surrounding quasar PKS 0454−22." Monthly Notices of the Royal Astronomical Society 505, no. 4 (June 12, 2021): 5497–513. http://dx.doi.org/10.1093/mnras/stab1647.
Повний текст джерелаАнотація:
ABSTRACT We report optical integral-field spectroscopy in the field of one of the most luminous quasars in the z < 1 Universe, PKS 0454−22, with the Multi-Unit Spectroscopic Explorer. These data enable the discovery of three large ionized nebulae emitting in [O ii], H β, and [O iii] with projected areas of 1720, 1520, and 130 pkpc2, which we refer to as N1, N2, and N3, respectively. N1 spatially and kinematically surrounds the quasar host and five nearby galaxies. The morphology and kinematics of N1 are most consistent with stripped interstellar medium resulting from ongoing interactions. Its ionization properties can be explained by quasar photoionization. N2 spatially and kinematically surrounds two galaxies that are at projected distances of d ≈ 90 pkpc and line-of-sight velocities of Δv ≈+1410 km s−1 from the quasar. The morphology and kinematics of N2 are also consistent with stripped interstellar medium. However, its ionization state requires additional ionization sources beyond the quasar, likely from fast shocks as it moves through the hot halo associated with a galaxy overdensity around the quasar. N3 is not coincident with any galaxies with secure redshifts, and may arise from a cool gas structure in the intragroup medium or a dwarf galaxy. These large ionized nebulae demonstrate that interactions can produce cool gas structures on halo scales, while also possibly facilitating quasar fueling. The growing availability of wide-area integral field spectroscopic data will continue to reveal the morphologies, kinematics, and conditions of the gas flows, which may fuel galaxy and black hole growth.
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Chebanov, L., A. Kiyanovskiy, T. Chebanov, and I. Lyashenko. "Classification of greenhouses with flexible coating." Ways to Improve Construction Efficiency 1, no. 50 (November 11, 2022): 125–36. http://dx.doi.org/10.32347/2707-501x.2022.50(1).125-136.
Повний текст джерелаАнотація:
The main types of modern greenhouses with a fence made of film (in one layer and double with an air layer) and polycarbonate are considered. Different methods of growing plants in natural and artificial substrates on trays, supports, and special tables are shown.
The elements of galvanized constructions of complete factory readiness differ in height, span, pitch of columns, number and position of elm blocks. The structural features of such buildings and structures make it possible to create many volume-planning solutions for the implementation of various agronomic technologies when growing vegetables and flowers, as well as meeting the needs of production and sanitary and household needs of workers.
Engineering and technological systems provide a comfortable micro-climate for plants at different times of the year. Passive ventilation is used (single and double butterfly type in the roof, in the side and end walls), as well as active with the possibility of air humidification
The concept of energy saving allows you to store (accumulate) heat in the tanks (systems) of boiler houses, including during operation of boiler houses in the summer to obtain carbon dioxide. In greenhouses, pipes are arranged in the underground space to preserve the energy of warm air in winter and cool the air in summer. Special methods of cleaning drainage drains allow you to save and reuse nutrients during drip irrigation of various plants.
The technology of building greenhouses involves the execution of works with sets of specialized machines, as well as universal machines with a set of interchangeable working bodies. For the mechanization of individual processes, special machines and mechanisms have been developed for welding of pipes, installation of foundations and elements of enclosing structures, etc.