Postfire seed rain of black spruce, a semiserotinous conifer, in forests of interior Alaska

Treesearch

Jill Johnstone; Leslie Boby; Emily Tissier; Michelle Mack; Dave Verbyla; Xanthe. Walker

2009-01-01

The availability of viable seed can act as an important constraint on plant regeneration following disturbance. This study presents data on seed quantity and quality for black spruce (Picea mariana (Mill.) B.S.P.), a semiserotinous conifer that dominates large areas of North American boreal forest. We sampled seed rain and viability for 2 years...

Two Years Necessary for Successful Natural Seeding in Nonbrushy Black Spruce Bogs

Treesearch

Elon S. Verry; Arthur E. Elling

1978-01-01

Natural seeding in a strip-cut black spruce bog was adequate, averaging 1,800 stems per acre and 80 percent milacre stocking. natural seeding in a completely cut bog was inadequate, averaging 630 stems per acre and 40 percent milacre stocking. Slash was removed to expose sphagnum seedbeds in both cases. Progressive cutting every other year is recommended.

Probing Primordial Black Hole Dark Matter with Gravitational Waves

NASA Astrophysics Data System (ADS)

Kovetz, Ely D.

2017-09-01

Primordial black holes (PBHs) have long been suggested as a candidate for making up some or all of the dark matter in the Universe. Most of the theoretically possible mass range for PBH dark matter has been ruled out with various null observations of expected signatures of their interaction with standard astrophysical objects. However, current constraints are significantly less robust in the 20 M⊙≲MPBH≲100 M⊙ mass window, which has received much attention recently, following the detection of merging black holes with estimated masses of ˜30 M⊙ by LIGO and the suggestion that these could be black holes formed in the early Universe. We consider the potential of advanced LIGO (aLIGO) operating at design sensitivity to probe this mass range by looking for peaks in the mass spectrum of detected events. To quantify the background, which is due to black holes that are formed from dying stars, we model the shape of the stellar-black-hole mass function and calibrate its amplitude to match the O 1 results. Adopting very conservative assumptions about the PBH and stellar-black-hole merger rates, we show that ˜5 yr of aLIGO data can be used to detect a contribution of >20 M⊙ PBHs to dark matter down to fPBH<0.5 at >99.9 % confidence level. Combined with other probes that already suggest tension with fPBH=1 , the obtainable independent limits from aLIGO will thus enable a firm test of the scenario that PBHs make up all of dark matter.

Gravitational-wave localization alone can probe origin of stellar-mass black hole mergers.

PubMed

Bartos, I; Haiman, Z; Marka, Z; Metzger, B D; Stone, N C; Marka, S

2017-10-10

The recent discovery of gravitational waves from stellar-mass binary black hole mergers by the Laser Interferometer Gravitational-wave Observatory opened the door to alternative probes of stellar and galactic evolution, cosmology and fundamental physics. Probing the origin of binary black hole mergers will be difficult due to the expected lack of electromagnetic emission and limited localization accuracy. Associations with rare host galaxy types-such as active galactic nuclei-can nevertheless be identified statistically through spatial correlation. Here we establish the feasibility of statistically proving the connection between binary black hole mergers and active galactic nuclei as hosts, even if only a sub-population of mergers originate from active galactic nuclei. Our results are the demonstration that the limited localization of gravitational waves, previously written off as not useful to distinguish progenitor channels, can in fact contribute key information, broadening the range of astrophysical questions probed by binary black hole observations.Binary black hole mergers have recently been observed through the detection of gravitational wave signatures. The authors demonstrate that their association with active galactic nuclei can be made through a statistical spatial correlation.

Visualizing tissue molecular structure of a black type of canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way.

PubMed

Yu, Peiqiang

2013-02-20

Heat-related processing of cereal grains, legume seeds, and oil seeds could be used to improve nutrient availability in ruminants. However, different types of processing may have a different impact on intrinsic structure of tissues. To date, there is little research on structure changes after processing within intact tissues. The synchrotron-based molecular imaging technique enables us to detect inherent structure change on a molecular level. The objective of this study was to visualize tissue of black-type canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way using the synchrotron imaging technique. The results showed that the chemical images of protein amides were obtained through the imaging technique for the raw, wet, and dry heated black type of canola seed tissues. It seems that different types of processing have a different impact on the protein spectral profile in the black type of canola tissues. Wet heating had a greater impact on the protein α-helix to β-sheet ratio than dry heating. Both dry and wet heating resulted in different patterns in amide I, the second derivative, and FSD spectra. However, the exact differences in the tissue images are relatively difficult to be obtained through visual comparison. Future studies should focus on (1) comparing the response and sensitivity of canola seeds to various processing methods between the yellow-type and black-type of canola seeds; (2) developing a sensitive method to compare the image difference between tissues and between treatments; (3) developing a method to link images to nutrient digestion, and (4) revealing how structure changes affect nutrient absorption in humans and animals.

Subfamily-Specific Fluorescent Probes for Cysteine Proteases Display Dynamic Protease Activities during Seed Germination.

PubMed

Lu, Haibin; Chandrasekar, Balakumaran; Oeljeklaus, Julian; Misas-Villamil, Johana C; Wang, Zheming; Shindo, Takayuki; Bogyo, Matthew; Kaiser, Markus; van der Hoorn, Renier A L

2015-08-01

Cysteine proteases are an important class of enzymes implicated in both developmental and defense-related programmed cell death and other biological processes in plants. Because there are dozens of cysteine proteases that are posttranslationally regulated by processing, environmental conditions, and inhibitors, new methodologies are required to study these pivotal enzymes individually. Here, we introduce fluorescence activity-based probes that specifically target three distinct cysteine protease subfamilies: aleurain-like proteases, cathepsin B-like proteases, and vacuolar processing enzymes. We applied protease activity profiling with these new probes on Arabidopsis (Arabidopsis thaliana) protease knockout lines and agroinfiltrated leaves to identify the probe targets and on other plant species to demonstrate their broad applicability. These probes revealed that most commercially available protease inhibitors target unexpected proteases in plants. When applied on germinating seeds, these probes reveal dynamic activities of aleurain-like proteases, cathepsin B-like proteases, and vacuolar processing enzymes, coinciding with the remobilization of seed storage proteins. © 2015 American Society of Plant Biologists. All Rights Reserved.

Probing Primordial Black Hole Dark Matter with Gravitational Waves.

PubMed

Kovetz, Ely D

2017-09-29

Primordial black holes (PBHs) have long been suggested as a candidate for making up some or all of the dark matter in the Universe. Most of the theoretically possible mass range for PBH dark matter has been ruled out with various null observations of expected signatures of their interaction with standard astrophysical objects. However, current constraints are significantly less robust in the 20  M_{⊙}≲M_{PBH}≲100  M_{⊙} mass window, which has received much attention recently, following the detection of merging black holes with estimated masses of ∼30  M_{⊙} by LIGO and the suggestion that these could be black holes formed in the early Universe. We consider the potential of advanced LIGO (aLIGO) operating at design sensitivity to probe this mass range by looking for peaks in the mass spectrum of detected events. To quantify the background, which is due to black holes that are formed from dying stars, we model the shape of the stellar-black-hole mass function and calibrate its amplitude to match the O1 results. Adopting very conservative assumptions about the PBH and stellar-black-hole merger rates, we show that ∼5  yr of aLIGO data can be used to detect a contribution of >20  M_{⊙} PBHs to dark matter down to f_{PBH}<0.5 at >99.9% confidence level. Combined with other probes that already suggest tension with f_{PBH}=1, the obtainable independent limits from aLIGO will thus enable a firm test of the scenario that PBHs make up all of dark matter.

Phytochemistry, pharmacology, and therapeutic uses of black seed (Nigella sativa).

PubMed

Kooti, Wesam; Hasanzadeh-Noohi, Zahra; Sharafi-Ahvazi, Naim; Asadi-Samani, Majid; Ashtary-Larky, Damoon

2016-10-01

Black seed (Nigella sativa) is an annual flowering plant from Ranunculaceae family, native to southwest Asia. This plant has many food and medicinal uses. The use of its seeds and oil is common for treatment of many diseases, including rheumatoid arthritis, asthma, inflammatory diseases, diabetes and digestive diseases. The purpose of this study was to provide a comprehensive review on the scientific reports that have been published about N. sativa. The facts and statistics presented in this review article were gathered from the journals accessible in creditable databases such as Science Direct, Medline, PubMed, Scopus, EBSCO, EMBASE, SID and IranMedex. The keywords searched in Persian and English books on medicinal plants and traditional medicine, as well as the above reputable databases were "Black seed", "Nigella sativa", "therapeutic effect", and "medicinal plant". The results showed that N. sativa has many biological effects such as anti-inflammatory, anti-hyperlipidemic, anti-microbial, anti-cancer, anti-oxidant, anti-diabetic, anti-hypertensive, and wound healing activities. It also has effects on reproductive, digestive, immune and central nervous systems, such as anticonvulsant and analgesic activities. In summary, it can be used as a valuable plant for production of new drugs for treatment of many diseases. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Purification and characterization of new phytoferritin from black bean (Phaseolus vulgaris L.) seed.

PubMed

Deng, Jianjun; Liao, Xiayun; Hu, Ju; Leng, Xiaojing; Cheng, Jianjun; Zhao, Guanghua

2010-05-01

In contrast to animal ferritin, relatively little information is available on phytoferritin. Black bean (Phaseolus vulgaris L.) has been consumed in many countries. In the present study, new ferritin from black bean seed was purified by two consecutive anion exchange and size exclusion chromatography. The apparent molecular mass of the native black bean seed ferritin (BSF) was found to be approximately 560 kDa by native PAGE analysis. N-terminal sequence, MALDI-TOF-MS and MS/MS analyses indicate that BSF and soybean seed ferritin (SSF) share very high identity in amino acid sequence. However, SDS-PAGE result indicates that BSF consists of 26.5 (H-1) and 28.0 kDa (H-2) subunits with a ratio of 2 : 1, while the ratio of these two subunits in SSF is 1 : 1. This result demonstrates that the two proteins have different subunit composition which might affect their activities in iron uptake and release. Indeed, at high iron flux, the initial rate of iron oxidative deposition in apoBSF is larger than that in apoSSF. On the contrary, the iron release from BSF is significantly slower than that from SSF. All these results indicate that phytoferritin might regulate the transit of iron into and out of the protein cavity by changing its subunit composition.

Light-energy processing and freezing-tolerance traits in red spruce and black spruce: species and seed-source variation.

PubMed

Major, John E; Barsi, Debby C; Mosseler, Alex; Campbell, Moira; Rajora, Om P

2003-07-01

Red spruce (Picea rubens Sarg.) and black spruce (Picea mariana (Mill.) B.S.P.) are genetically and morphologically similar but ecologically distinct species. We determined intraspecific seed-source and interspecific variation of red spruce and black spruce, from across the near-northern margins of their ranges, for several light-energy processing and freezing-tolerance adaptive traits. Before exposure to low temperature, red spruce had variable fluorescence (Fv) similar to black spruce, but higher photochemical efficiency (Fv/Fm), lower quantum yield, lower chlorophyll fluorescence (%), and higher thermal dissipation efficiency (qN), although the seed-source effect and the seed-source x species interaction were significant only for Fv/Fm. After low-temperature exposure (-40 degrees C), red spruce had significantly lower Fv/Fm, quantum yield and qN than black spruce, but higher chlorophyll fluorescence and relative fluorescence. Species, seed-source effect, and seed-source x species interaction were consistent with predictions based on genetic (e.g., geographic) origins. Multi-temperature exposures (5, -20 and -40 degrees C) often produced significant species and temperature effects, and species x temperature interactions as a result of species-specific responses to temperature exposures. The inherent physiological species-specific adaptations of red spruce and black spruce were largely consistent with a shade-tolerant, late-successional species and an early successional species, respectively. Species differences in physiological adaptations conform to a biological trade-off, probably as a result of natural selection pressure in response to light availability and prevailing temperature gradients.

Early Growth of Black Walnut Trees From Twenty Seed Sources

Treesearch

Calvin F. Bey; John R. Toliver; Paul L. Roth

1971-01-01

Early results of a black walnut cornseed source study conducted in southern Illinois suggest that seed should be collected from local or south-of-local areas. Trees from southern sources grew faster and longer than trees from northern sources. Trees from southern sources flushed slightly earlier and held their leaves longer than trees from northern sources. For the...

Proteolytic activity of selected moulds in the first fermentation of black-seeded soysauce

NASA Astrophysics Data System (ADS)

Yulifianti, R.; Ginting, E.

2018-01-01

Black-seeded soybean is preferred as normally it has higher protein content and would give black colour to the soyfiltrate for making soysauce. Mould is usually used in the first fermentation of soysauce making to prepare koji with high soluble protein as a media for the subsequent bacteria fermentation in brine solution. Black-seeded soybean of Detam 1 variety was used as the soysauce ingredient. The trial was a randomized complete design with four replicates. The treatments were (1) Rhizopus oligosporus starter (in flour form) with two day-fermentation, (2) similar R. oligosporus starter with three-day fermentation, (3) Aspergillus sojae (pure culture) with three-day fermentation and (4) A. sojae in flour form with three-day fermentation. The black-seeded soybean had 100-grain weight of 11.7 g, high protein content of 42.5% dw and fat content of 14.9% dw. Koji prepared using R. oligosporus starter with two-day fermentation had the lowest protein content (48.9% dw). Both starters of A. sojae culture and flour gave the highest soluble protein content of koji (41.0-41.5% dw), followed by R. oligosporus starter with 3 day-fermentation (35.2% dw). Whilst the lowest value was noted in koji prepared using R. oligosporus starter with two day-fermentation (30.8% dw). This suggests that both A. sojae starters had similar proteolitic activity and higher than that of R. oligosporus starter. In terms of practical application and maintenance of the mould viability by soysauce processors, the use of A. sojae flour starter with three-day fermentation is suggested.

Age and size effects on seed productivity of northern black spruce

Treesearch

J. N. Viglas; C. D. Brown; J. F. Johnstone

2013-01-01

Slow-growing conifers of the northern boreal forest may require several decades to reach reproductive maturity, making them vulnerable to increases in disturbance frequency. Here, we examine the relationship between stand age and seed productivity of black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) in Yukon Territory and Alaska....

Chasing the observational signatures of seed black holes at z > 7: candidate observability

NASA Astrophysics Data System (ADS)

Valiante, Rosa; Schneider, Raffaella; Zappacosta, Luca; Graziani, Luca; Pezzulli, Edwige; Volonteri, Marta

2018-05-01

Observing the light emitted by the first accreting black holes (BHs) would dramatically improve our understanding of the formation of quasars at z > 6, possibly unveiling the nature of their supermassive black hole (SMBH) seeds. In previous works, we explored the relative role of the two main competing BH seed formation channels, Population III remnants (low-mass seeds) and direct collapse BHs (high-mass seeds), investigating the properties of their host galaxies in a cosmological context. Building on this analysis, we predict here the spectral energy distribution and observational features of low- and high-mass BH seeds selected among the progenitors of a z ˜ 6 SMBH. We derive the processed emission from both accreting BHs and stars by using the photoionization code CLOUDY, accounting for the evolution of metallicity and dust-to-gas mass ratio in the interstellar medium of the host galaxies, as predicted by the cosmological data-constrained model GAMETE/QSODUST. We show how future missions like James Webb Space Telescope (JWST) and Advanced Telescope for High Energy Astrophysics (ATHENA) will be able to detect the light coming from SMBH progenitors already at z ˜ 16. We build upon previous complementary studies and propose a method based on the combined analysis of near-infrared colours, IR excess (IRX), and UV continuum slopes (i.e. colour-colour and IRX-β diagrams) to distinguish growing seed BH host galaxies from starburst-dominated systems in JWST surveys. Sources selected through this criterion would be the best target for follow-up X-ray observations.

Locations of radical species in black pepper seeds investigated by CW EPR and 9 GHz EPR imaging

NASA Astrophysics Data System (ADS)

Nakagawa, Kouichi; Epel, Boris

2014-10-01

In this study, noninvasive 9 GHz electron paramagnetic resonance (EPR)-imaging and continuous wave (CW) EPR were used to investigate the locations of paramagnetic species in black pepper seeds without further irradiation. First, lithium phthalocyanine (LiPC) phantom was used to examine 9 GHz EPR imaging capabilities. The 9 GHz EPR-imager easily resolved the LiPC samples at a distance of ∼2 mm. Then, commercially available black pepper seeds were measured. We observed signatures from three different radical species, which were assigned to stable organic radicals, Fe3+, and Mn2+ complexes. In addition, no EPR spectral change in the seed was observed after it was submerged in distilled H2O for 1 h. The EPR and spectral-spatial EPR imaging results suggested that the three paramagnetic species were mostly located at the seed surface. Fewer radicals were found inside the seed. We demonstrated that the CW EPR and 9 GHz EPR imaging were useful for the determination of the spatial distribution of paramagnetic species in various seeds.

Locations of radical species in black pepper seeds investigated by CW EPR and 9GHz EPR imaging.

PubMed

Nakagawa, Kouichi; Epel, Boris

2014-10-15

In this study, noninvasive 9GHz electron paramagnetic resonance (EPR)-imaging and continuous wave (CW) EPR were used to investigate the locations of paramagnetic species in black pepper seeds without further irradiation. First, lithium phthalocyanine (LiPC) phantom was used to examine 9GHz EPR imaging capabilities. The 9GHz EPR-imager easily resolved the LiPC samples at a distance of ∼2mm. Then, commercially available black pepper seeds were measured. We observed signatures from three different radical species, which were assigned to stable organic radicals, Fe(3+), and Mn(2+) complexes. In addition, no EPR spectral change in the seed was observed after it was submerged in distilled H2O for 1h. The EPR and spectral-spatial EPR imaging results suggested that the three paramagnetic species were mostly located at the seed surface. Fewer radicals were found inside the seed. We demonstrated that the CW EPR and 9GHz EPR imaging were useful for the determination of the spatial distribution of paramagnetic species in various seeds. Copyright © 2014 Elsevier B.V. All rights reserved.

The safety and pharmacokinetics of cyanidin-3-glucoside after 2-week administration of black bean seed coat extract in healthy subjects.

PubMed

Jeon, Sangil; Han, Seunghoon; Lee, Jongtae; Hong, Taegon; Yim, Dong-Seok

2012-08-01

We analyzed the pharmacokinetics of C3G on data from twelve subjects, after 2-week multiple dosing of black bean (Phaseolus vulgaris, Cheongjakong-3-ho) seed coat extract, using the mixed effect analysis method (NONMEM, Ver. 6.2), as well as the conventional non-compartmental method. We also examined the safety and tolerability. The PK analysis used plasma concentrations of the C3G on day 1 and 14. There was no observed accumulation of C3G after 2-week multiple dosing of black bean seed coat extract. The typical point estimates of PK were CL (clearance)=3,420 l/h, V (volume)=7,280 L, Ka (absorption constant)=9.94 h(-1), ALAG (lag time)=0.217 h. The black bean seed coat extract was well tolerated and there were no serious adverse events. In this study, we confirmed that a significant amount of C3G was absorbed in human after given the black bean seed coat extract.

Volatile emission in dry seeds as a way to probe chemical reactions during initial asymptomatic deterioration

USDA-ARS?s Scientific Manuscript database

The nature and kinetics of reactions in dry seeds determines how long they survive. We used gas chromatography to assay volatile organic compounds (VOC) emitted from seeds of three unrelated species as a means to non-invasively probe chemical changes during very dry, dry and humid (15, 33 and 75% RH...

Phytochemical Contents and Antioxidant and Antiproliferative Activities of Selected Black and White Sesame Seeds

PubMed Central

Abbasi, Arshad Mehmood; Zheng, Bisheng

2016-01-01

Sesame (Sesamum indicum L.) seeds are popular nutritional food but with limited knowledge about their antioxidant and antiproliferative activities of various varieties. Phytochemical profiles and antioxidant and antiproliferative activities of six varieties of sesame (Sesamum indicum L.) seeds were studied. Fenheizhi3 (black) cultivar exhibited the maximum contents of total phenolics and lignans and values of total oxygen radical absorbance capacity (ORAC) and antiproliferative activity (EC50) against HepG2 cells. Bound ORAC values showed strong associations with bound phenolics contents (r = 0.976, p < 0.01); in bound phenolic extracts, EC50 values showed strong negative associations with phenolic contents (r = −0.869, p < 0.05) and ORAC values (r = −0.918, p < 0.01). Moreover, the contents of free phenolics were higher than that of the bound phenolics, and the three black sesame seeds generally depicted higher total phenolics compared to the three white varieties. The antioxidant (ORAC values) and antiproliferation activities of six sesame seeds were both associated with contents of bound phenolics (r > 0.8, p < 0.05). Interestingly, nonlignan components in bound phenolics contributed to the antioxidant and antiproliferative activities. This study suggested that Fenheizhi3 variety is superior to the other five varieties as antioxidant supplements. PMID:27597975

Consumption of seeds of southwestern white pine (Pinus strobiformis) by Black Bear (Ursus americanus)

USGS Publications Warehouse

Mattson, David J.; Arundel, Terry A.

2013-01-01

We report a discovery of black bears (Ursus americanus) consuming seeds of southwestern white pine (Pinus strobiformis) on north slopes of the San Francisco Peaks near Flagstaff, Arizona, in high-elevation, mixed-species conifer forest. In one instance, a bear had obtained seeds from cones excavated from a larder horde made by a red squirrel (Tamiasciurus hudsonicus). Consumption of seeds of southwestern white pine by bears had not been previously documented. This discovery adds to the number of species of pine used by bears for food as well as the geographic range within which the behavior occurs.

Massive primordial black holes from hybrid inflation as dark matter and the seeds of galaxies

NASA Astrophysics Data System (ADS)

Clesse, Sébastien; García-Bellido, Juan

2015-07-01

In this paper we present a new scenario where massive primordial black holes (PBHs) are produced from the collapse of large curvature perturbations generated during a mild-waterfall phase of hybrid inflation. We determine the values of the inflaton potential parameters leading to a PBH mass spectrum peaking on planetarylike masses at matter-radiation equality and producing abundances comparable to those of dark matter today, while the matter power spectrum on scales probed by cosmic microwave background (CMB) anisotropies agrees with Planck data. These PBHs could have acquired large stellar masses today, via merging, and the model passes both the constraints from CMB distortions and microlensing. This scenario is supported by Chandra observations of numerous BH candidates in the central region of Andromeda. Moreover, the tail of the PBH mass distribution could be responsible for the seeds of supermassive black holes at the center of galaxies, as well as for ultraluminous x-ray sources. We find that our effective hybrid potential can originate e.g. from D-term inflation with a Fayet-Iliopoulos term of the order of the Planck scale but sub-Planckian values of the inflaton field. Finally, we discuss the implications of quantum diffusion at the instability point of the potential, able to generate a Swiss-cheese-like structure of the Universe, eventually leading to apparent accelerated cosmic expansion.

Progress report: effects of fertilization on vegetative growth and early flowering and fruiting of seed orchard black cherry

Treesearch

Donald E. Dorn; L. R. Auchmoody

1974-01-01

Black cherry (Prunus serotina Ehrh.) seedling seed orchards are now being established on the Allegheny and Monongahela National Forests (Fig. 1). It has been estimated that ten to twenty years may be required from the time that a seed orchard is established until it begins to produce large quantities of seed. Therefore, anything that could be done to...

Comparison of germination and seed bank dynamics of dimorphic seeds of the cold desert halophyte Suaeda corniculata subsp. mongolica

PubMed Central

Cao, Dechang; Baskin, Carol C.; Baskin, Jerry M.; Yang, Fan; Huang, Zhenying

2012-01-01

Background and Aims Differences in dormancy and germination requirements have been documented in heteromorphic seeds of many species, but it is unknown how this difference contributes to maintenance and regeneration of populations. The primary aim of this study was to compare the seed bank dynamics, including dormancy cycling, of the two seed morphs (black and brown) of the cold desert halophyte Suaeda corniculata and, if differences were found, to determine their influence on regeneration of the species. Method Seeds of the two seed morphs were buried, exhumed and tested monthly for 24 months over a range of temperatures and salinities, and germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were also investigated for the two morphs. Key Results Black seeds had an annual dormancy/non-dormancy cycle, while brown seeds, which were non-dormant at maturity, remained non-dormant. Black seeds also exhibited an annual cycle in sensitivity of germination to salinity. Seedlings derived from black seeds emerged in July and August and those from brown seeds in May. Seedlings were recruited from 2·6 % of the black seeds and from 2·8 % of the brown seeds in the soil, and only 0·5 % and 0·4 % of the total number of black and brown seeds in the soil, respectively, gave rise to seedlings that survived to produce seeds. Salinity and water stress induced dormancy in black seeds and decreased viability of brown seeds. Brown seeds formed only a transient soil seed bank and black seeds a persistent seed bank. Conclusions The presence of a dormancy cycle in black but not in brown seeds of S. corniculata and differences in germination requirements of the two morphs cause them to differ in their germination dynamics. The study contributes to our limited knowledge of dormancy cycling and seed bank formation in species producing heteromorphic seeds. PMID:22975287

Comparison of germination and seed bank dynamics of dimorphic seeds of the cold desert halophyte Suaeda corniculata subsp. mongolica.

PubMed

Cao, Dechang; Baskin, Carol C; Baskin, Jerry M; Yang, Fan; Huang, Zhenying

2012-12-01

Differences in dormancy and germination requirements have been documented in heteromorphic seeds of many species, but it is unknown how this difference contributes to maintenance and regeneration of populations. The primary aim of this study was to compare the seed bank dynamics, including dormancy cycling, of the two seed morphs (black and brown) of the cold desert halophyte Suaeda corniculata and, if differences were found, to determine their influence on regeneration of the species. Seeds of the two seed morphs were buried, exhumed and tested monthly for 24 months over a range of temperatures and salinities, and germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were also investigated for the two morphs. Black seeds had an annual dormancy/non-dormancy cycle, while brown seeds, which were non-dormant at maturity, remained non-dormant. Black seeds also exhibited an annual cycle in sensitivity of germination to salinity. Seedlings derived from black seeds emerged in July and August and those from brown seeds in May. Seedlings were recruited from 2·6 % of the black seeds and from 2·8 % of the brown seeds in the soil, and only 0·5 % and 0·4 % of the total number of black and brown seeds in the soil, respectively, gave rise to seedlings that survived to produce seeds. Salinity and water stress induced dormancy in black seeds and decreased viability of brown seeds. Brown seeds formed only a transient soil seed bank and black seeds a persistent seed bank. The presence of a dormancy cycle in black but not in brown seeds of S. corniculata and differences in germination requirements of the two morphs cause them to differ in their germination dynamics. The study contributes to our limited knowledge of dormancy cycling and seed bank formation in species producing heteromorphic seeds.

A gaseous acetic acid treatment to disinfect fenugreek seeds and black pepper inoculated with pathogenic and spoilage bacteria.

PubMed

Nei, Daisuke; Enomoto, Katsuyoshi; Nakamura, Nobutaka

2015-08-01

Contamination of spices by pathogenic and/or spoilage bacteria can be deleterious to consumer's health and cause deterioration of foods, and inactivation of such bacteria is necessary for the food industry. The present study examined the effect of gaseous acetic acid treatment in reducing Escherichia coli O157:H7, Salmonella Enteritidis and Bacillus subtilis populations inoculated on fenugreek seeds and black pepper. Treatment with gaseous acetic acid at 0.3 mmol/L, 0.6 mmol/L and 4.7 mmol/L for 1-3 h significantly reduced the populations of E. coli O157:H7 and Salmonella Enteritidis on black pepper and fenugreek seeds at 55 °C (p < 0.05). The gas treatments at 4.7 mmol/L were more effective in inactivating the pathogens than the treatment at 0.3 mmol/L. An approximately 5.0 log reduction was obtained after 3 h of treatment with 4.7 mmol/L acetic acid. No significant reductions in the population of B. subtilis spores inoculated on fenugreek seeds and black pepper were obtained after the gas treatments at 0.3 mmol/L or 0.6 mmol/L (p > 0.05). However, the gas treatment at 4.7 mmol/L significantly reduced B. subtilis spores (p < 0.05), and 4.0 log CFU/g and 3.5 log CFU/g reductions on fenugreek seeds and black pepper, respectively, were obtained after 3 h of treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

X-ray Winds from Black Holes

NASA Astrophysics Data System (ADS)

Miller, Jon M.

2017-08-01

Across the mass scale, high-resolution X-ray spectroscopy has transformed our view of accretion onto black holes. The ionized disk winds observed from stellar-mass black holes may sometimes eject more mass than is able to accrete onto the black hole. It is possible that these winds can probe the fundamental physics that drive disk accretion. The most powerful winds from accretion onto massive black holes may play a role in feedback, seeding host bulges with hot gas and halting star formation. The lessons and techniques emerging from these efforts can also reveal the accretion flow geometry in tidal disruption events (TDEs), an especially rich discovery space. This talk will review some recent progress enabled by high-resolution X-ray spectroscopy, and look at the potential of gratings spectrometers and microcalorimeters in the years ahead.

Genetic control of a transition from black to straw-white seed hull in rice domestication.

PubMed

Zhu, Bo-Feng; Si, Lizhen; Wang, Zixuan; Zhou, Yan; Zhu, Jinjie; Shangguan, Yingying; Lu, Danfeng; Fan, Danlin; Li, Canyang; Lin, Hongxuan; Qian, Qian; Sang, Tao; Zhou, Bo; Minobe, Yuzo; Han, Bin

2011-03-01

The genetic mechanism involved in a transition from the black-colored seed hull of the ancestral wild rice (Oryza rufipogon and Oryza nivara) to the straw-white seed hull of cultivated rice (Oryza sativa) during grain ripening remains unknown. We report that the black hull of O. rufipogon was controlled by the Black hull4 (Bh4) gene, which was fine-mapped to an 8.8-kb region on rice chromosome 4 using a cross between O. rufipogon W1943 (black hull) and O. sativa indica cv Guangluai 4 (straw-white hull). Bh4 encodes an amino acid transporter. A 22-bp deletion within exon 3 of the bh4 variant disrupted the Bh4 function, leading to the straw-white hull in cultivated rice. Transgenic study indicated that Bh4 could restore the black pigment on hulls in cv Guangluai 4 and Kasalath. Bh4 sequence alignment of all taxa with the outgroup Oryza barthii showed that the wild rice maintained comparable levels of nucleotide diversity that were about 70 times higher than those in the cultivated rice. The results from the maximum likelihood Hudson-Kreitman-Aguade test suggested that the significant reduction in nucleotide diversity in rice cultivars could be caused by artificial selection. We propose that the straw-white hull was selected as an important visual phenotype of nonshattered grains during rice domestication.

Seed dimorphism, nutrients and salinity differentially affect seed traits of the desert halophyte Suaeda aralocaspica via multiple maternal effects.

PubMed

Wang, Lei; Baskin, Jerry M; Baskin, Carol C; Cornelissen, J Hans C; Dong, Ming; Huang, Zhenying

2012-09-25

Maternal effects may influence a range of seed traits simultaneously and are likely to be context-dependent. Disentangling the interactions of plant phenotype and growth environment on various seed traits is important for understanding regeneration and establishment of species in natural environments. Here, we used the seed-dimorphic plant Suaeda aralocaspica to test the hypothesis that seed traits are regulated by multiple maternal effects. Plants grown from brown seeds had a higher brown:black seed ratio than plants from black seeds, and germination percentage of brown seeds was higher than that of black seeds under all conditions tested. However, the coefficient of variation (CV) for size of black seeds was higher than that of brown seeds. Seeds had the smallest CV at low nutrient and high salinity for plants from brown seeds and at low nutrient and low salinity for plants from black seeds. Low levels of nutrients increased size and germinability of black seeds but did not change the seed morph ratio or size and germinability of brown seeds. High levels of salinity decreased seed size but did not change the seed morph ratio. Seeds from high-salinity maternal plants had a higher germination percentage regardless of level of germination salinity. Our study supports the multiple maternal effects hypothesis. Seed dimorphism, nutrient and salinity interacted in determining a range of seed traits of S. aralocaspica via bet-hedging and anticipatory maternal effects. This study highlights the importance of examining different maternal factors and various offspring traits in studies that estimate maternal effects on regeneration.

Seed dimorphism, nutrients and salinity differentially affect seed traits of the desert halophyte Suaeda aralocaspica via multiple maternal effects

PubMed Central

2012-01-01

Background Maternal effects may influence a range of seed traits simultaneously and are likely to be context-dependent. Disentangling the interactions of plant phenotype and growth environment on various seed traits is important for understanding regeneration and establishment of species in natural environments. Here, we used the seed-dimorphic plant Suaeda aralocaspica to test the hypothesis that seed traits are regulated by multiple maternal effects. Results Plants grown from brown seeds had a higher brown:black seed ratio than plants from black seeds, and germination percentage of brown seeds was higher than that of black seeds under all conditions tested. However, the coefficient of variation (CV) for size of black seeds was higher than that of brown seeds. Seeds had the smallest CV at low nutrient and high salinity for plants from brown seeds and at low nutrient and low salinity for plants from black seeds. Low levels of nutrients increased size and germinability of black seeds but did not change the seed morph ratio or size and germinability of brown seeds. High levels of salinity decreased seed size but did not change the seed morph ratio. Seeds from high-salinity maternal plants had a higher germination percentage regardless of level of germination salinity. Conclusions Our study supports the multiple maternal effects hypothesis. Seed dimorphism, nutrient and salinity interacted in determining a range of seed traits of S. aralocaspica via bet-hedging and anticipatory maternal effects. This study highlights the importance of examining different maternal factors and various offspring traits in studies that estimate maternal effects on regeneration. PMID:23006315

Effects of vesicular-arbuscular mycorrhizae and seed source on nursery-grown black walnut seedlings

Treesearch

B. L. Brookshire; H. E. Garrett; T. L. Robison

2003-01-01

A nursery study was established in Missouri to evaluate the effects of endomycorrhizal inoculation and seed source on the growth of black walnut seedlings. Inoculation, in general, resulted in seedlings with significantly larger sturdiness quotients. Glomus intraradicies was found to produce larger seedlings than Glomus etunicatus...

New probe of dark-matter properties: gravitational waves from an intermediate-mass black hole embedded in a dark-matter minispike.

PubMed

Eda, Kazunari; Itoh, Yousuke; Kuroyanagi, Sachiko; Silk, Joseph

2013-05-31

An intermediate-mass black hole (IMBH) may have a dark-matter (DM) minihalo around it and develop a spiky structure within less than a parsec from the IMBH. When a stellar mass object is captured by the minihalo, it eventually infalls into such an IMBH due to gravitational wave backreaction which in turn could be observed directly by future space-borne gravitational wave experiments such as eLISA and NGO. In this Letter, we show that the gravitational wave (GW) detectability strongly depends on the radial profile of the DM distribution. So if the GW is detected, the power index, that is, the DM density distribution, would be determined very accurately. The DM density distribution obtained would make it clear how the IMBH has evolved from a seed black hole and whether the IMBH has experienced major mergers in the past. Unlike the γ-ray observations of DM annihilation, GW is just sensitive to the radial profile of the DM distribution and even to noninteracting DM. Hence, the effect we demonstrate here can be used as a new and powerful probe into DM properties.

Comparative effects of using black seed (Nigella sativa), cumin seed (Cuminum cyminum), probiotic or prebiotic on growth performance, blood haematology and serum biochemistry of broiler chicks.

PubMed

Alimohamadi, K; Taherpour, K; Ghasemi, H A; Fatahnia, F

2014-06-01

A 42-day trial was conducted to compare the effects of the following seven experimental diets, which varied in black seed, cumin seed, probiotic or prebiotic concentrations, on the broiler chicks: control (no additives), diet BS1 (4 g/kg black seed), diet BS2 (8 g/kg black seed), diet CS1 (4 g/kg cumin seed), diet CS2 (8 g/kg cumin seed), diet Pro (1 g/kg probiotic Primalac(®)) and diet Pre (2 g/kg prebiotic Fermacto(®)). A total of 420 1-day-old male broiler chicks, initially weighing an average of 43 g, were distributed into 28 floor pens at a stocking density of 15 birds per pen. At 28 day of age, the body weight in the birds fed diets BS2, CS2 and Pro was significantly higher than in the control group, but final body weight was not affected. Additionally, the birds fed diets BS2, Pro and Pre exhibited better feed conversion ratio than control birds from 0 to 42 day of age. Diets BS2, CS2 and Pro also statistically increased the relative weight of thymus and bursa of Fabricius, whereas only diet Pro decreased the abdominal fat percentage compared with control diet. Regarding the haematological parameters, feeding diet BS2 yielded a significant increase in red blood cell count, haemoglobin concentration and haematocrit percentage compared with control diet. Serum total cholesterol and low-density lipoprotein cholesterol levels in the birds fed diets BS2, Pro and Pre were also significantly lower than in the birds fed the control diet. Without exception, no diets affected feed intake, internal organs weights, carcass characteristics, antibody titres against Newcastle and influenza viruses and leucocyte subsets. In general, current study showed promising results regarding the use of spice additives as growth and health promoters, especially at higher levels of their incorporation in the diets, which were comparable to the probiotic- or prebiotic-containing diets. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

Chasing the observational signatures of seed black holes at z > 7: candidate statistics

NASA Astrophysics Data System (ADS)

Valiante, Rosa; Schneider, Raffaella; Graziani, Luca; Zappacosta, Luca

2018-03-01

Supermassive black holes (SMBHs) of 109-1010 M⊙ were already in place ˜13 Gyr ago, at z > 6. Super-Eddington growth of low-mass BH seeds (˜100 M⊙) or less extreme accretion on to˜105 M⊙ seeds have been recently considered as the main viable routes to these SMBHs. Here, we study the statistics of these SMBH progenitors at z ˜ 6. The growth of low- and high-mass seeds and their host galaxies are consistently followed using the cosmological data constrained model GAMETE/QSODUST, which reproduces the observed properties of high-z quasars, like SDSS J1148+5251. We show that both seed formation channels can be in action over a similar redshift range 15 < z < 18 and are found in dark matter haloes with comparable mass, ˜5 × 107 M⊙. However, as long as the systems evolve in isolation (i.e. no mergers occur), noticeable differences in their properties emerge: At z ≥ 10 galaxies hosting high-mass seeds have smaller stellar mass and metallicity, the BHs accrete gas at higher rates and star formation proceeds less efficiently than in low-mass seeds hosts. At z < 10 these differences are progressively erased, as the systems experience minor or major mergers and every trace of the BH origin gets lost.

Needs of Seeds

ERIC Educational Resources Information Center

Keeley, Page

2011-01-01

The "Needs of Seeds" formative assessment probe can be used to find out whether students recognize that seeds have needs both similar to and different from plants and other living organisms (Keeley, Eberle, and Tugel 2007). The probe reveals whether students overgeneralize the needs of seeds by assuming they have the same needs as the adult plants…

The influence of pulsed electric fields and microwave pretreatments on some selected physicochemical properties of oil extracted from black cumin seed.

PubMed

Bakhshabadi, Hamid; Mirzaei, HabibOllah; Ghodsvali, Alireza; Jafari, Seid Mahdi; Ziaiifar, Aman Mohammad

2018-01-01

Application of novel technologies such as microwave and pulsed electric fields (PEF) might increase the speed and efficiency of oil extraction. In the present research, PEF (3.25 kV/cm electric field intensity and 30 pulse number) and microwave (540 W for 180 s) pretreatments were used to study the process of oil extraction from black cumin ( Nigella sativa ) seeds. After applying the selected pretreatments, the oil of seeds was extracted with the use of a screw press and the extraction efficiency, refractive index, oil density, color index, oxidative stability, and chemical components of oil and protein of meal were evaluated. The achieved results expressed that PEF and microwave pretreatments increased the oil extraction efficiency and its oxidative stability. Different pretreatments didn't have any significant influence on the refractive index of black cumin seed oil ( p >.05). When microwave and PEF were used, the oil density showed an enhancement as the following: 1.51% and 0.96%, respectively in comparison with the samples with no pretreatments. Evaluation of the extracted oils, using GC/MS analysis indicated that thymoquinone was the dominant phenolic component in the black cumin oil. Finally, the SEM analysis revealed that microwave and PEF can be useful in the extraction of oil from black cumin seeds since these treatments damaged cell walls and facilitated the oil extraction process.

A simple differential pulse polarographic method for the determination of thymoquinone in black seed oil.

PubMed

Michelitsch, Astrid; Rittmannsberger, Anna

2003-01-01

A reliable and simple differential pulse polarographic method is described for the determination of thymoquinone in black seed oil. The polarographic behaviour of thymoquinone was examined in various buffer systems over the pH range 5.0-10.0. Thymoquinone is reduced in a single, reversible peak at the dropping mercury electrode. The differential pulse polarogram showed a distinct peak in Sörensen buffer:methanol (3:7, v/v; pH 8.5) at a peak potential of -0.095 V (vs. silver/silver chloride electrode), and a plot of peak height against concentration was found to be linear over the range 0.2-15.0 microg/mL (R = 0.9998). The limit of detection was calculated to be 0.054 microg/mL. The polarographic method has been applied to determine thymoquinone in two black seed oil preparations available on the Austrian pharmaceutical market.

In vivo photoacoustic imaging of prostate brachytherapy seeds

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin; Boctor, Emad M.

2014-03-01

We conducted an approved canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. Brachytherapy seeds coated with black ink were inserted into the canine prostate using methods similar to a human procedure. A transperineal, interstitial, fiber optic light delivery method, coupled to a 1064 nm laser, was utilized to irradiate the prostate and the resulting acoustic waves were detected with a transrectal ultrasound probe. The fiber was inserted into a high dose rate (HDR) brachytherapy needle that acted as a light-diffusing sheath, enabling radial light delivery from the tip of the fiber inside the sheath. The axis of the fiber was located at a distance of 4-9 mm from the long axis of the cylindrical seeds. Ultrasound images acquired with the transrectal probe and post-operative CT images of the implanted seeds were analyzed to confirm seed locations. In vivo limitations with insufficient light delivery within the ANSI laser safety limit (100 mJ/cm2) were overcome by utilizing a short-lag spatial coherence (SLSC) beamformer, which provided average seed contrasts of 20-30 dB for energy densities ranging 8-84 mJ/cm2. The average contrast was improved by up to 20 dB with SLSC beamforming compared to conventional delay-and-sum beamforming. There was excellent agreement between photoacoustic, ultrasound, and CT images. Challenges included visualization of photoacoustic artifacts that corresponded with locations of the optical fiber and hyperechoic tissue structures.

Effects of germination time on seed morph ratio in a seed-dimorphic species and possible ecological significance

PubMed Central

Yang, Fan; Baskin, Jerry M.; Baskin, Carol C.; Yang, Xuejun; Cao, Dechang; Huang, Zhenying

2015-01-01

Background and Aims Diaspores of heteromorphic species may germinate at different times due to distinct dormancy-breaking and germination requirements, and this difference can influence life history traits. The primary aim of this study was to determine the effect of germination time of the two seed morphs of Suaeda corniculata subsp. mongolica on life history traits of the offspring. Methods Germinated brown and black seeds were sown on the 20th of each month from April to September in a simulated but near-natural habitat of the species. Phenological and vegetative traits of the maternal plants, and number, size and germination percentage of the offspring were determined. Key Results Germinated seeds sown late in the year produced smaller plants that had a higher proportion of non-dormant brown than dormant black seeds, and these brown seeds were larger than those produced by germinated seeds sown early in the year. The length of the seedling stage for brown seeds was shorter than that for black seeds, and the root/shoot ratio and reproductive allocation of plants from brown seeds were more variable than they were for plants from black seeds. Late-germinating brown seeds produced larger plants than late-germinating black seeds. Conclusions Altering the proportion of the two seed types in response to germination timing can help alleviate the adverse effects of delayed germination. The flexible strategy of a species, such as S. corniculata, that produces different proportions of dimorphic seeds in response to variation in germination timing may favour the maintenance and regeneration of the population in its unpredictable environment. PMID:25395107

From here to eternity - the secret of Pharaohs: Therapeutic potential of black cumin seeds and beyond

PubMed Central

Padhye, Subhash; Banerjee, Sanjeev; Ahmad, Aamir; Mohammad, Ramzi; Sarkar, Fazlul H

2008-01-01

Summary Over many centuries humans have been mining the bounties of nature for discovering substances that have been used for the treatment of all human diseases; many such remedies are useful even today as modern day medicine. Emerging evidence also suggests that the search is still continuing for harnessing active compounds from nature in combating human illnesses although pharmaceutical industries are equally active for synthesizing small molecule compounds as novel therapeutics. The lesson learned over many centuries clearly suggests that further sophisticated search for finding compounds from natural resources together with robust characterization and chemical synthesis will lead to the discovery of novel drugs that may have high therapeutic efficacy against all human diseases including cancer. Black cumin seed (Nigella sativa) oil extracts have been used for many centuries for the treatment of many human illnesses, and more recently the active compound found in black seed oil, viz. thymoquinone (TQ) has been tested for its efficacy against several diseases including cancer. However, further research is needed in order to assess the full potential of TQ as a chemopreventive and/or therapeutic agent against cancers. Here, we have summarized what is known regarding the value of black seed oil and its active compound TQ, and how this knowledge will help us to advance further research in this field by creating awareness among scientists and health professionals in order to appreciate the medicinal value of TQ and beyond. PMID:19018291

Probing Massive Black Hole Populations and Their Environments with LISA

NASA Astrophysics Data System (ADS)

Katz, Michael; Larson, Shane

2018-01-01

With the adoption of the LISA Mission Proposal by the European Space Agency in response to its call for L3 mission concepts, gravitational wave measurements from space are on the horizon. With data from the Illustris large-scale cosmological simulation, we provide analysis of LISA detection rates accompanied by characterization of the merging Massive Black Holes (MBH) and their host galaxies. MBHs of total mass $\\sim10^6-10^9 M_\\odot$ are the main focus of this study. Using a precise treatment of the dynamical friction evolutionary process prior to gravitational wave emission, we evolve MBH simulation particle mergers from $\\sim$kpc scales until coalescence to achieve a merger distribution. Using the statistical basis of the Illustris output, we Monte-carlo synthesize many realizations of the merging massive black hole population across space and time. We use those realizations to build mock LISA detection catalogs to understand the impact of LISA mission configurations on our ability to probe massive black hole merger populations and their environments throughout the visible Universe.

Anthocyanins extracted from black soybean seed coat protect primary cortical neurons against in vitro ischemia.

PubMed

Bhuiyan, Mohammad Iqbal Hossain; Kim, Joo Youn; Ha, Tae Joung; Kim, Seong Yun; Cho, Kyung-Ok

2012-01-01

The present study investigated the neuroprotective effects of anthocyanins extracted from black soybean (cv. Cheongja 3, Glycine max (L.) MERR.) seed coat against oxygen-glucose deprivation (OGD) and glutamate-induced cell death in rat primary cortical neurons. Lactate dehydrogenase (LDH) release and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assays were employed to assess cell membrane damage and viability of primary neurons, respectively. OGD-induced cell death in 7 d in vitro primary cortical neurons was found to be OGD duration-dependent, and approximately 3.5 h of OGD resulted in ≈60% cell death. Treatment with black soybean anthocyanins dose-dependently prevented membrane damage and increased the viability of primary neurons that were exposed to OGD. Glutamate-induced neuronal cell death was dependent on the glutamate concentration at relatively low concentrations and the number of days the cells remained in culture. Interestingly, black soybean anthocyanins did not protect against glutamate-induced neuronal cell death. They did, however, inhibit the excessive generation of reactive oxygen species (ROS) and preserve mitochondrial membrane potential (MMP) in primary neurons exposed to OGD. In agreement with the neuroprotective effect of crude black soybean anthocyanins, purified cyanidin-3-glucoside (C3G), the major component of anthocyanins, also offered dose-dependent neuroprotection against OGD-induced neuronal cell death. Moreover, black soybean C3G markedly prevented excessive generation of ROS and preserved MMP in primary neurons that were exposed to OGD. Collectively, these results suggest that the neuroprotection of primary rat cortical neurons by anthocyanins that were extracted from black soybean seed coat might be mediated through oxidative stress inhibition and MMP preservation but not through glutamate-induced excitotoxicity attenuation.

Growing massive black holes through supercritical accretion of stellar-mass seeds

NASA Astrophysics Data System (ADS)

Lupi, A.; Haardt, F.; Dotti, M.; Fiacconi, D.; Mayer, L.; Madau, P.

2016-03-01

The rapid assembly of the massive black holes that power the luminous quasars observed at z ˜ 6-7 remains a puzzle. Various direct collapse models have been proposed to head-start black hole growth from initial seeds with masses ˜105 M⊙, which can then reach a billion solar mass while accreting at the Eddington limit. Here, we propose an alternative scenario based on radiatively inefficient supercritical accretion of stellar-mass holes embedded in the gaseous circumnuclear discs (CNDs) expected to exist in the cores of high-redshift galaxies. Our sub-pc resolution hydrodynamical simulations show that stellar-mass holes orbiting within the central 100 pc of the CND bind to very high density gas clumps that arise from the fragmentation of the surrounding gas. Owing to the large reservoir of dense cold gas available, a stellar-mass black hole allowed to grow at super-Eddington rates according to the `slim-disc' solution can increase its mass by three orders of magnitudes within a few million years. These findings are supported by simulations run with two different hydro codes, RAMSES based on the Adaptive Mesh Refinement technique and GIZMO based on a new Lagrangian Godunov-type method, and with similar, but not identical, sub-grid recipes for star formation, supernova feedback, black hole accretion and feedback. The low radiative efficiency of supercritical accretion flows are instrumental to the rapid mass growth of our black holes, as they imply modest radiative heating of the surrounding nuclear environment.

Primordial black holes as seeds of magnetic fields in the universe

NASA Astrophysics Data System (ADS)

Safarzadeh, Mohammadtaher

2018-06-01

Although it is assumed that magnetic fields in accretion disks are dragged from the interstellar medium, the idea is likely not applicable to primordial black holes (PBHs) formed in the early universe. Here we show that magnetic fields can be generated in initially unmagnetized accretion disks around PBHs through the Biermann battery mechanism, and therefore provide the small scale seeds of magnetic field in the universe. The radial temperature and vertical density profiles of these disks provide the necessary conditions for the battery to operate naturally. The generated seed fields have a toroidal structure with opposite sign in the upper and lower half of the disk. In the case of a thin accretion disk around a rotating PBH, the field generation rate increases with increasing PBH spin. At a fixed r/risco, where r is the radial distance from the PBH and risco is the radius of the innermost stable circular orbit, the battery scales as M-9/4, where M is the PBH's mass. The very weak dependency of the battery on accretion rate, makes this mechanism a viable candidate to provide seed fields in an initially unmagnetized accretion disk, following which the magnetorotational instability could take over.

Delivery of Flavonoids and Saponins from Black Bean (Phaseolus vulgaris) Seed Coats Incorporated into Whole Wheat Bread

PubMed Central

Chávez-Santoscoy, Rocio A.; Lazo-Vélez, Marco A.; Serna-Sáldivar, Sergio O.; Gutiérrez-Uribe, Janet A.

2016-01-01

Cereal-based products can be used as vehicles for the delivery of relevant bioactive compounds since they are staple foods for most cultures throughout the world. The health promoting benefits of flavonoids and saponins contained in black bean seed coats have been previously described. In the present work, the effect of adding flavonoids and saponins from black bean seed coat to the typical yeast-leavened whole wheat bread formulation in terms of bread features, organoleptic properties and phytochemical profile was studied. The retention of bioactive compounds was determined and the inhibitory effects of in vitro enzyme digested samples on two colon cancer cell lines (Caco-2 and HT29) was evaluated. The addition of bioactive compounds did not significantly affect baking properties or texture parameters. Among organoleptic properties of enriched breads, only crumb color was affected by the addition of bioactive compounds. However, the use of whole wheat flour partially masked the effect on color. More than 90% of added flavonoids and saponins and 80% of anthocyanins were retained in bread after baking. However, saponins were reduced more than 50% after the in vitro enzyme digestion. The black bean seed coat phytochemicals recovered after in vitro enzyme digestion of enriched breads significantly reduced by 20% the viability of colon cancer cells without affecting standard fibroblast cells (p < 0.05). PMID:26901186

Delivery of Flavonoids and Saponins from Black Bean (Phaseolus vulgaris) Seed Coats Incorporated into Whole Wheat Bread.

PubMed

Chávez-Santoscoy, Rocio A; Lazo-Vélez, Marco A; Serna-Sáldivar, Sergio O; Gutiérrez-Uribe, Janet A

2016-02-17

Cereal-based products can be used as vehicles for the delivery of relevant bioactive compounds since they are staple foods for most cultures throughout the world. The health promoting benefits of flavonoids and saponins contained in black bean seed coats have been previously described. In the present work, the effect of adding flavonoids and saponins from black bean seed coat to the typical yeast-leavened whole wheat bread formulation in terms of bread features, organoleptic properties and phytochemical profile was studied. The retention of bioactive compounds was determined and the inhibitory effects of in vitro enzyme digested samples on two colon cancer cell lines (Caco-2 and HT29) was evaluated. The addition of bioactive compounds did not significantly affect baking properties or texture parameters. Among organoleptic properties of enriched breads, only crumb color was affected by the addition of bioactive compounds. However, the use of whole wheat flour partially masked the effect on color. More than 90% of added flavonoids and saponins and 80% of anthocyanins were retained in bread after baking. However, saponins were reduced more than 50% after the in vitro enzyme digestion. The black bean seed coat phytochemicals recovered after in vitro enzyme digestion of enriched breads significantly reduced by 20% the viability of colon cancer cells without affecting standard fibroblast cells (p < 0.05).

Amelioration of tamoxifen-induced liver injury in rats by grape seed extract, black seed extract and curcumin.

PubMed

El-Beshbishy, Hesham A; Mohamadin, Ahmed M; Nagy, Ayman A; Abdel-Naim, Ashraf B

2010-03-01

Liver injury was induced in female rats using tamoxifen (TAM). Grape seeds (Vitis vinifera) extract (GSE), black seed (Nigella sativa) extract (NSE), curcumin (CUR) or silymarin (SYL) were orally administered to TAM-intoxicated rats. Liver histopathology of TAM-intoxicated:rats showed pathological changes. TAM-intoxication elicited declines in liver antioxidant enzymes levels (glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase), reduced glutathione (GSH) and GSH/GSSG ratio plus the hepatic elevations in lipid peroxides, oxidized glutathione (GSSG), tumor necrosis factor-alpha (TNF-alpha) and serum liver enzymes; alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase and gamma glutamyl transferase levels. Oral intake of NSE, GSE, CUR or SYL to TAM-intoxicated rats, attenuated histopathological changes and corrected all parameters mentioned above. Improvements were prominent in case of NSE (similarly SYL) > CUR > GSE. Data indicated that NSE, GSE or CUR act as free radicals scavengers and protect TAM-induced liver injury in rats.

Identification of Weather Conditions Associated with the Occurrence, Severity, and Incidence of Black Seed Disease of Strawberry Caused by Mycosphaerella fragariae.

PubMed

Carisse, Odile; McNealis, Vanessa

2018-01-01

Black seed disease (BSD) of strawberry is a sporadic disease caused by Mycosphaerella fragariae. Because little is known about potential crop losses or the weather conditions conducive to disease development, fungicides are generally not applied or are applied based on a preset schedule. Data collected from 2000 to 2011 representing 50 farm-years (total of 186 strawberry fields) were used to determine potential crop losses and to study the influence of weather on disease occurrence and development. First, logistic regression was used to model the relationship between occurrence of BSD and weather variables. Second, linear and nonlinear regressions were used to model the number of black seed per berry (severity) and the percentage of diseased berries (incidence). Of the 186 fields monitored, 78 showed black seed symptoms, and the number of black seed per berry ranged from 1 to 10, whereas the percentage of diseased berries ranged from 3 to 32%. The most influential weather variable was total rainfall (in millimeters) in May, with a threshold of 103 mm of rain (absence of BSD < 103 mm < presence of BSD). Similarly, nonlinear models with the total rainfall in May accurately predicted both disease severity and incidence (r = 0.94 and 0.97, respectively). Considering that management actions such as fungicide application are not needed every year in every field, these models could be used to identify fields that are at risk of BSD.

Widely tunable two-colour seeded free-electron laser source for resonant-pump resonant-probe magnetic scattering

PubMed Central

Ferrari, Eugenio; Spezzani, Carlo; Fortuna, Franck; Delaunay, Renaud; Vidal, Franck; Nikolov, Ivaylo; Cinquegrana, Paolo; Diviacco, Bruno; Gauthier, David; Penco, Giuseppe; Ribič, Primož Rebernik; Roussel, Eleonore; Trovò, Marco; Moussy, Jean-Baptiste; Pincelli, Tommaso; Lounis, Lounès; Manfredda, Michele; Pedersoli, Emanuele; Capotondi, Flavio; Svetina, Cristian; Mahne, Nicola; Zangrando, Marco; Raimondi, Lorenzo; Demidovich, Alexander; Giannessi, Luca; De Ninno, Giovanni; Danailov, Miltcho Boyanov; Allaria, Enrico; Sacchi, Maurizio

2016-01-01

The advent of free-electron laser (FEL) sources delivering two synchronized pulses of different wavelengths (or colours) has made available a whole range of novel pump–probe experiments. This communication describes a major step forward using a new configuration of the FERMI FEL-seeded source to deliver two pulses with different wavelengths, each tunable independently over a broad spectral range with adjustable time delay. The FEL scheme makes use of two seed laser beams of different wavelengths and of a split radiator section to generate two extreme ultraviolet pulses from distinct portions of the same electron bunch. The tunability range of this new two-colour source meets the requirements of double-resonant FEL pump/FEL probe time-resolved studies. We demonstrate its performance in a proof-of-principle magnetic scattering experiment in Fe–Ni compounds, by tuning the FEL wavelengths to the Fe and Ni 3p resonances. PMID:26757813

Formation of massive seed black holes via collisions and accretion

NASA Astrophysics Data System (ADS)

Boekholt, T. C. N.; Schleicher, D. R. G.; Fellhauer, M.; Klessen, R. S.; Reinoso, B.; Stutz, A. M.; Haemmerlé, L.

2018-05-01

Models aiming to explain the formation of massive black hole seeds, and in particular the direct collapse scenario, face substantial difficulties. These are rooted in rather ad hoc and fine-tuned initial conditions, such as the simultaneous requirements of extremely low metallicities and strong radiation backgrounds. Here, we explore a modification of such scenarios where a massive primordial star cluster is initially produced. Subsequent stellar collisions give rise to the formation of massive (104-105 M⊙) objects. Our calculations demonstrate that the interplay among stellar dynamics, gas accretion, and protostellar evolution is particularly relevant. Gas accretion on to the protostars enhances their radii, resulting in an enhanced collisional cross-section. We show that the fraction of collisions can increase from 0.1 to 1 per cent of the initial population to about 10 per cent when compared to gas-free models or models of protostellar clusters in the local Universe. We conclude that very massive objects can form in spite of initial fragmentation, making the first massive protostellar clusters viable candidate birth places for observed supermassive black holes.

Planting yellow-poplar, white ash, black cherry, and black locust

Treesearch

Robert D. Williams; Calvin F. Bey

1989-01-01

Hardwood plantations that include yellow-poplar, white ash, black cherry, and black locust can be established on upland sites in the central hardwoods region (see Note 3.06 Seeding and Planting Upland Oaks, and Note 3.08 Seeding and Planting Walnut). Even though hardwoods are more difficult to establish than conifers, there are...

Volatile emission in dry seeds as a way to probe chemical reactions during initial asymptomatic deterioration.

PubMed

Mira, Sara; Hill, Lisa M; González-Benito, M Elena; Ibáñez, Miguel Angel; Walters, Christina

2016-03-01

The nature and kinetics of reactions in dry seeds determines how long the seeds survive. We used gas chromatography to assay volatile organic compounds (VOCs) emitted from seeds of three unrelated species as a means to non-invasively probe chemical changes during very dry, dry, and humid storage (seeds were dried to 5.5, 33, and 75% relative humidity at room temperature). VOCs emitted from seeds stored in humid conditions reflected fermentation-type reactions, with methanol and ethanol being predominant in Lactuca sativa and Carum carvi, and acetaldehyde and acetone being predominant in Eruca vesicaria. Dried C. carvi seeds continued to emit fermentation-type products, although at slower rates than the seeds stored in humid conditions. In contrast, drying caused a switch in VOC emission in L. sativa and E. vesicaria seeds towards higher emission of pentane and hexanal, molecules considered to be byproducts from the peroxidation of polyunsaturated fatty acids. Longevity correlated best with the rate of fermentation-type reactions and appeared unrelated to the rate of lipid peroxidation. Emission of VOCs decreased when seed species were mixed together, indicating that seeds adsorbed VOCs. Adsorption of VOCs did not appear to damage seeds, as longevity was not affected in seed mixtures. Collectively, the study shows similarity among species in the types of reactions that occur in dry seeds, but high diversity in the substrates, and hence the byproducts, of the reactions. Moreover, the study suggests that the most abundant VOCs arise from degradation of storage reserves within seed cells, and that these reactions and their byproducts are not, in themselves, damaging. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Volatile emission in dry seeds as a way to probe chemical reactions during initial asymptomatic deterioration

PubMed Central

Mira, Sara; Hill, Lisa M.; González-Benito, M. Elena; Ibáñez, Miguel Angel; Walters, Christina

2016-01-01

The nature and kinetics of reactions in dry seeds determines how long the seeds survive. We used gas chromatography to assay volatile organic compounds (VOCs) emitted from seeds of three unrelated species as a means to non-invasively probe chemical changes during very dry, dry, and humid storage (seeds were dried to 5.5, 33, and 75% relative humidity at room temperature). VOCs emitted from seeds stored in humid conditions reflected fermentation-type reactions, with methanol and ethanol being predominant in Lactuca sativa and Carum carvi, and acetaldehyde and acetone being predominant in Eruca vesicaria. Dried C. carvi seeds continued to emit fermentation-type products, although at slower rates than the seeds stored in humid conditions. In contrast, drying caused a switch in VOC emission in L. sativa and E. vesicaria seeds towards higher emission of pentane and hexanal, molecules considered to be byproducts from the peroxidation of polyunsaturated fatty acids. Longevity correlated best with the rate of fermentation-type reactions and appeared unrelated to the rate of lipid peroxidation. Emission of VOCs decreased when seed species were mixed together, indicating that seeds adsorbed VOCs. Adsorption of VOCs did not appear to damage seeds, as longevity was not affected in seed mixtures. Collectively, the study shows similarity among species in the types of reactions that occur in dry seeds, but high diversity in the substrates, and hence the byproducts, of the reactions. Moreover, the study suggests that the most abundant VOCs arise from degradation of storage reserves within seed cells, and that these reactions and their byproducts are not, in themselves, damaging. PMID:26956506

Black howler monkey (Alouatta pigra) activity, foraging and seed dispersal patterns in shaded cocoa plantations versus rainforest in southern Mexico.

PubMed

Zárate, Diego A; Andresen, Ellen; Estrada, Alejandro; Serio-Silva, Juan Carlos

2014-09-01

Recent evidence has shown that primates worldwide use agroecosystems as temporary or permanent habitats. Detailed information on how these primates are using these systems is scant, and yet their role as seed dispersers is often implied. The main objective of this study was to compare the activity, foraging patterns and seed dispersal role of black howler monkeys (Alouatta pigra) inhabiting shaded cocoa plantations and rainforest in southern Chiapas, Mexico. We gathered data on three monkey groups living in shaded cocoa plantations and three groups living in rainforest, using focal sampling, and collecting fecal samples. General activity and foraging patterns were similar in both habitats, with the exception that monkeys in the cocoa habitat spent more time feeding on petioles. Monkeys in shaded cocoa plantations dispersed 51,369 seeds (4% were seeds ≥3 mm width) of 16 plant species. Monkeys in the rainforest dispersed 6,536 seeds (78% were seeds ≥3 mm width) of 13 plant species. Our data suggest that the difference between habitats in the proportion of large versus small seeds dispersed reflects differences in fruit species abundance and availability in cocoa versus forest. Mean seed dispersal distances were statistically similar in both habitats (cocoa = 149 m, forest = 86 m). We conclude that the studied cocoa plantations provide all elements necessary to constitute a long-term permanent habitat for black howler monkeys. In turn, howler monkeys living in these plantations are able to maintain their functional role as seed dispersers for those native tree and liana species present within their areas of activities. © 2014 Wiley Periodicals, Inc.

Probing the Accretion Geometry of Black Holes with X-Ray Polarization

NASA Technical Reports Server (NTRS)

Schnitman, Jeremy D.

2011-01-01

In the coming years, new space missions will be able to measure X-ray polarization at levels of 1% or better in the approx.1-10 keV energy band. In particular, X-ray polarization is an ideal tool for determining the nature of black hole (BH) accretion disks surrounded by hot coronae. Using a Monte Carlo radiation transport code in full general relativity, we calculate the spectra and polarization features of these BH systems. At low energies, the signal is dominated by the thermal flux coming directly from the optically thick disk. At higher energies, the thermal seed photons have been inverse-Compton scattered by the corona, often reflecting back off the disk before reaching the observer, giving a distinctive polarization signature. By measuring the degree and angle of this X-ray polarization, we can infer the BH inclination, the emission geometry of the accretion flow, and also determine the spin of the black hole.

Effect of different levels of feed added black seed (Nigella sativa L.) on the performance of broiler chicks.

PubMed

Durrani, F R; Chand, N; Zaka, K; Sultan, A; Khattak, F M; Durrani, Z

2007-11-15

The study was conducted to investigate the effect of different levels of feed added black seed (Nigella sativa L.) on the overall performance and immunity of broiler chicks at NWFP Agricultural University, Peshawar in May 2005. Four experimental rations designated as A, B, C and D having black seed at the rate of 0, 20, 30 and 40 g kg(-1) feed were fed to 160 broiler chicks, randomly distributed into 16 replicates, so as to have 4 replicates per group and 10 chicks per replicate. The experiment was lasted for 35 days. Average weight gain, feed consumption, feed efficiency, dressing percentage, weight of different body organs (breast, thigh, intestine), giblets (liver, gizzard), abdominal fat weight, antibody titer against ND, IB and IBD were used as criteria of response. Economics for each group was calculated at the end of experimental period. It was found that group D receiving 40 g kg(-1) of black seed in the feed had a significant (p < 0.05) effect on mean body weight gain, feed intake, feed conversion ratio, dressing percentage and weight of different body organs (breast and thigh). Non significant (p > 0.05) effect was observed in gizzard, intestine, weight of abdominal fat and feed cost. Antibody titer against ND and IBD were higher in group D, however high antibody titer against IB was recorded in group C. Return per unit of feed cost and gross return were significantly (p < 0.05) effected by group D.

Genetic Control of a Transition from Black to Straw-White Seed Hull in Rice Domestication1[C][W][OA

PubMed Central

Zhu, Bo-Feng; Si, Lizhen; Wang, Zixuan; Jingjie Zhu, Yan Zhou; Shangguan, Yingying; Lu, Danfeng; Fan, Danlin; Li, Canyang; Lin, Hongxuan; Qian, Qian; Sang, Tao; Zhou, Bo; Minobe, Yuzo; Han, Bin

2011-01-01

The genetic mechanism involved in a transition from the black-colored seed hull of the ancestral wild rice (Oryza rufipogon and Oryza nivara) to the straw-white seed hull of cultivated rice (Oryza sativa) during grain ripening remains unknown. We report that the black hull of O. rufipogon was controlled by the Black hull4 (Bh4) gene, which was fine-mapped to an 8.8-kb region on rice chromosome 4 using a cross between O. rufipogon W1943 (black hull) and O. sativa indica cv Guangluai 4 (straw-white hull). Bh4 encodes an amino acid transporter. A 22-bp deletion within exon 3 of the bh4 variant disrupted the Bh4 function, leading to the straw-white hull in cultivated rice. Transgenic study indicated that Bh4 could restore the black pigment on hulls in cv Guangluai 4 and Kasalath. Bh4 sequence alignment of all taxa with the outgroup Oryza barthii showed that the wild rice maintained comparable levels of nucleotide diversity that were about 70 times higher than those in the cultivated rice. The results from the maximum likelihood Hudson-Kreitman-Aguade test suggested that the significant reduction in nucleotide diversity in rice cultivars could be caused by artificial selection. We propose that the straw-white hull was selected as an important visual phenotype of nonshattered grains during rice domestication. PMID:21263038

Water entry for the black locust (Robinia pseudoacacia L.) seeds observed by dedicated micro-magnetic resonance imaging.

PubMed

Koizumi, Mika; Kano, Hiromi

2016-07-01

Water entry at germination for black locust (Robinia pseudoacacia L.) seeds which are known as hard seeds with impermeable seed coat to water, was examined using micro-magnetic resonance imaging (MRI). The MRI apparatus equipped with a low-field (1 T; Tesla) permanent magnet was used, which is open access, easy maintenance, operable and transportable. The excellent point of the apparatus is that T 1-enhancement of water signals absorbed in dry seeds against steeping free water is stronger than the apparatuses with high-field superconducting magnets, which enabled clear detection of water entry. Water hardly penetrated into the seeds for more than 8 h but approximately 60 % of seeds germinated by incubating on wet filter papers for several days. Hot water treatments above 75 °C for 3 min effectively induced water gap; scarification was 70 % at 100 °C and 75 °C, declined to 15 % at 50 °C and decreased further at room temperature. Water entered into the scarified seeds exclusively through the lens, spread along the dorsal side of the seeds and reached the hypocotyl, whereas water migrated slowly through hilum side to radicle within 3 h.

Genome-Wide Survey of Flavonoid Biosynthesis Genes and Gene Expression Analysis between Black- and Yellow-Seeded Brassica napus

PubMed Central

Qu, Cunmin; Zhao, Huiyan; Fu, Fuyou; Wang, Zhen; Zhang, Kai; Zhou, Yan; Wang, Xin; Wang, Rui; Xu, Xinfu; Tang, Zhanglin; Lu, Kun; Li, Jia-Na

2016-01-01

Flavonoids, the compounds that impart color to fruits, flowers, and seeds, are the most widespread secondary metabolites in plants. However, a systematic analysis of these loci has not been performed in Brassicaceae. In this study, we isolated 649 nucleotide sequences related to flavonoid biosynthesis, i.e., the Transparent Testa (TT) genes, and their associated amino acid sequences in 17 Brassicaceae species, grouped into Arabidopsis or Brassicaceae subgroups. Moreover, 36 copies of 21 genes of the flavonoid biosynthesis pathway were identified in Arabidopsis thaliana, 53 were identified in Brassica rapa, 50 in Brassica oleracea, and 95 in B. napus, followed the genomic distribution, collinearity analysis and genes triplication of them among Brassicaceae species. The results showed that the extensive gene loss, whole genome triplication, and diploidization that occurred after divergence from the common ancestor. Using qRT-PCR methods, we analyzed the expression of 18 flavonoid biosynthesis genes in 6 yellow- and black-seeded B. napus inbred lines with different genetic background, found that 12 of which were preferentially expressed during seed development, whereas the remaining genes were expressed in all B. napus tissues examined. Moreover, 14 of these genes showed significant differences in expression level during seed development, and all but four of these (i.e., BnTT5, BnTT7, BnTT10, and BnTTG1) had similar expression patterns among the yellow- and black-seeded B. napus. Results showed that the structural genes (BnTT3, BnTT18, and BnBAN), regulatory genes (BnTTG2 and BnTT16) and three encoding transfer proteins (BnTT12, BnTT19, and BnAHA10) might play an crucial roles in the formation of different seed coat colors in B. napus. These data will be helpful for illustrating the molecular mechanisms of flavonoid biosynthesis in Brassicaceae species. PMID:27999578

Short and long term modulation of tissue minerals concentrations following oral administration of black cumin (Nigella sativa L.) seed oil to laboratory rats.

PubMed

Basheer, Irum; Qureshi, Irfan Zia

2018-01-15

Nigella sativa, or commonly called black cumin is a small herb of family Ranunculaceae is a well-known medicinal plant but its effects on tissue mineral concentrations of animal bodies is unknown. To study the effect of oral administration of fixed oil of black cumin seeds on tissues mineral content using laboratory rats as experimental model. Experimental animals were exposed to two oral doses of seed oil (60 and 120 ml kg -1 body weight). Short- and long term experiments lasted 24 h and 60 days respectively, with three replicates each. Oil extracted from black cumin seeds was subjected to GC-MS to identify chemical components. Following the wet digestion in nitric acid, samples of whole blood and organs of rats were subjected to atomic absorption spectrophotometry for determination of elements concentrations. Data were compared statistically at p < .05. Compared to control, Cr, Mn, Ni, Cu, Zn showed decrease, whereas Co, Na, Mg and K demonstrated increase, but Ca showed both increase and decrease in most of the tissues upon short term exposure to low and high doses of black cumin oil. During long term exposure, Cr, Fe, Mn, Cu exhibited decrease; Co, Na, Mg and Ca concentrations demonstrated an upregulation, whereas Ni and Zn showed increase and decrease in most of the tissues. Comparison of short term with long term experiments at low dose revealed increases in Fe, Zn, Cu, Mg, K and Ca, a decrease in Cr, Mn, Ni and Cu in most tissues, but both increase and decrease in Na. At high dose, an increase occurred in Fe, Ni, Zn, K, Ca, Mg, a decrease in Cr, while both increase and decrease in Cu, Co and Na concentrations. Our study demonstrates that oral administration of black cumin seeds oil to laboratory rats significantly alters tissue trace elements and electrolytes concentrations. The study appears beneficial but indicates modulatory role of black cumin oil as regards mineral metabolism with far reaching implications in health and disease. Copyright © 2017

Unveiling early black holes with JWST

NASA Astrophysics Data System (ADS)

Natarajan, Priyamvada

The formation of direct collapse black hole seeds with masses ~104 - 105 ~M⊙ could help explain the assembly of supermassive black holes powering high redshift quasars. Conditions conducive to the formation of these massive initial seeds exist at high redshift. Halos hosting these massive seeds merge promptly with a nearby galaxy. These early stage mergers at high redshift produce a new class of transient galaxies that contain an accreting black hole that is over-massive compared to the newly acquired stellar component - Obese Black hole Galaxies (OBGs). During this phase, the accretion luminosity of the direct collapse black hole seed exceeds that of the acquired stellar component. Here we calculate the multi-wavelength spectrum of this short-lived OBG stage, and show that there exist unique observational signatures in long wavelengths spanning near, mid to far-infrared that should be detectable by instruments aboard the upcoming James Webb Space Telescope (JWST).

Cardiovascular benefits of black cumin (Nigella sativa).

PubMed

Shabana, Adel; El-Menyar, Ayman; Asim, Mohammad; Al-Azzeh, Hiba; Al Thani, Hassan

2013-03-01

Black Cumin (Nigella sativa), which belongs to the botanical family of Ranunculaceae, commonly grows in Eastern Europe, the Middle East, and Western Asia. Its ripe fruit contains tiny black seeds, known as "Al-Habba Al-Sauda" and "Al-Habba Al-Barakah" in Arabic and black seed or black cumin in English. Seeds of Nigella sativa are frequently used in folk medicine in the Middle East and some Asian countries for the promotion of good health and the treatment of many ailments. However, data for the cardiovascular benefits of black cumin are not well-established. We reviewed the literature from 1960 to March 2012 by using the following key words: "Nigella sativa," "black seeds," and "thymoquinone." Herein, we discussed the most relevant articles to find out the role of Nigella sativa in the cardiovascular diseases spectrum especially when there is a paucity of information and need of further studies in human to establish the utility of Nigella sativa in cardiovascular system protection.

Flavonoids and saponins extracted from black bean (Phaseolus vulgaris L.) seed coats modulate lipid metabolism and biliary cholesterol secretion in C57BL/6 mice.

PubMed

Chavez-Santoscoy, Rocio A; Gutierrez-Uribe, Janet A; Granados, Omar; Torre-Villalvazo, Ivan; Serna-Saldivar, Sergio O; Torres, Nimbe; Palacios-González, Berenice; Tovar, Armando R

2014-09-28

Black bean (Phaseolus vulgaris L.) seed coats are a rich source of natural compounds with potential beneficial effects on human health. Beans exert hypolipidaemic activity; however, this effect has not been attributed to any particular component, and the underlying mechanisms of action and protein targets remain unknown. The aim of the present study was to identify and quantify primary saponins and flavonoids extracted from black bean seed coats, and to study their effects on lipid metabolism in primary rat hepatocytes and C57BL/6 mice. The methanol extract of black bean seed coats, characterised by a HPLC system with a UV-visible detector and an evaporative light-scattering detector and HPLC-time-of-flight/MS, contained quercetin 3-O-glucoside and soyasaponin Af as the primary flavonoid and saponin, respectively. The extract significantly reduced the expression of SREBP1c, FAS and HMGCR, and stimulated the expression of the reverse cholesterol transporters ABCG5/ABCG8 and CYP7A1 in the liver. In addition, there was an increase in the expression of hepatic PPAR-α. Consequently, there was a decrease in hepatic lipid depots and a significant increase in bile acid secretion. Furthermore, the ingestion of this extract modulated the proportion of lipids that was used as a substrate for energy generation. Thus, the results suggest that the extract of black bean seed coats may decrease hepatic lipogenesis and stimulate cholesterol excretion, in part, via bile acid synthesis.

Roles of Gibberellins and Abscisic Acid in Regulating Germination of Suaeda salsa Dimorphic Seeds Under Salt Stress

PubMed Central

Li, Weiqiang; Yamaguchi, Shinjiro; Khan, M. Ajmal; An, Ping; Liu, Xiaojing; Tran, Lam-Son P.

2016-01-01

Seed heteromorphism observed in many halophytes is an adaptive phenomenon toward high salinity. However, the relationship between heteromorphic seed germination and germination-related hormones under salt stress remains elusive. To gain an insight into this relationship, the roles of gibberellins (GAs) and abscisic acid (ABA) in regulating germination of Suaeda salsa dimorphic brown and black seeds under salinity were elucidated by studying the kinetics of the two hormones during germination of the two seed types with or without salinity treatment. Morphological analysis suggested that brown and black are in different development stage. The content of ABA was higher in dry brown than in black seeds, which gradually decreased after imbibition in water and salt solutions. Salt stress induced ABA accumulation in both germinating seed types, with higher induction effect on black than brown seeds. Black seeds showed lower germination percentage than brown seeds under both water and salt stress, which might be attributed to their higher ABA sensitivity rather than the difference in ABA content between black and brown seeds. Bioactive GA4 and its biosynthetic precursors showed higher levels in brown than in black seeds, whereas deactivated GAs showed higher content in black than brown seeds in dry or in germinating water or salt solutions. High salinity inhibited seed germination through decreasing the levels of GA4 in both seeds, and the inhibited effect of salt stress on GA4 level of black seeds was more profound than that of brown seeds. Taken together higher GA4 content, and lower ABA sensitivity contributed to the higher germination percentage of brown seeds than black seeds in water and salinity; increased ABA content and sensitivity, and decreased GA4 content by salinity were more profound in black than brown seeds, which contributed to lower germination of black seeds than brown seeds in salinity. The differential regulation of ABA and GA homeostases by salt

Transcriptomic profiling of genes in matured dimorphic seeds of euhalophyte Suaeda salsa.

PubMed

Xu, Yange; Zhao, Yuanqin; Duan, Huimin; Sui, Na; Yuan, Fang; Song, Jie

2017-09-13

Suaeda salsa (S. salsa) is a euhalophyte with high economic value. S. salsa can produce dimorphic seeds. Brown seeds are more salt tolerant, can germinate quickly and maintain the fitness of the species under high saline conditions. Black seeds are less salt tolerant, may become part of the seed bank and germinate when soil salinity is reduced. Previous reports have mainly focused on the ecophysiological traits of seed germination and production under saline conditions in this species. However, there is no information available on the molecular characteristics of S. salsa dimorphic seeds. In the present study, a total of 5825 differentially expressed genes were obtained; and 4648 differentially expressed genes were annotated based on a sequence similarity search, utilizing five public databases by transcriptome analysis. The different expression of these genes may be associated with embryo development, fatty acid, osmotic regulation substances and plant hormones in brown and black seeds. Compared to black seeds, most genes may relate to embryo development, and various genes that encode fatty acid desaturase and are involved in osmotic regulation substance synthesis or transport are upregulated in brown seeds. A large number of differentially expressed genes related to plant hormones were found in brown and black seeds, and their possible roles in regulating seed dormancy/germination were discussed. Upregulated genes involved in seed development and osmotic regulation substance accumulation may relate to bigger seed size and rapid seed germination in brown seeds, compared to black seeds. Differentially expressed genes of hormones may relate to seed dormancy/germination and the development of brown and black seeds. The transcriptome dataset will serve as a valuable resource to further understand gene expression and functional genomics in S. salsa dimorphic seeds.

Antiviral effects of black raspberry (Rubus coreanus) seed extract and its polyphenolic compounds on norovirus surrogates.

PubMed

Lee, Ji-Hye; Bae, Sun Young; Oh, Mi; Seok, Jong Hyeon; Kim, Sella; Chung, Yeon Bin; Gowda K, Giri; Mun, Ji Young; Chung, Mi Sook; Kim, Kyung Hyun

2016-06-01

Black raspberry seeds, a byproduct of wine and juice production, contain large quantities of polyphenolic compounds. The antiviral effects of black raspberry seed extract (RCS) and its fraction with molecular weight less than 1 kDa (RCS-F1) were examined against food-borne viral surrogates, murine norovirus-1 (MNV-1) and feline calicivirus-F9 (FCV-F9). The maximal antiviral effect was achieved when RCS or RCS-F1 was added simultaneously to cells with MNV-1 or FCV-F9, reaching complete inhibition at 0.1-1 mg/mL. Transmission electron microscopy (TEM) images showed enlarged viral capsids or disruption (from 35 nm to up to 100 nm) by RCS-F1. Our results thus suggest that RCS-F1 can interfere with the attachment of viral surface protein to host cells. Further, two polyphenolic compounds derived from RCS-F1, cyanidin-3-glucoside (C3G) and gallic acid, identified by liquid chromatography-tandem mass spectrometry, showed inhibitory effects against the viruses. C3G was suggested to bind to MNV-1 RNA polymerase and to enlarge viral capsids using differential scanning fluorimetry and TEM, respectively.

EPR imaging and HPLC characterization of the pigment-based organic free radical in black soybean seeds.

PubMed

Nakagawa, Kouichi; Maeda, Hayato

2017-02-01

We investigated the location and distribution of paramagnetic species in dry black, brown, and yellow (normal) soybean seeds using electron paramagnetic resonance (EPR), X-band (9 GHz) EPR imaging (EPRI), and HPLC. EPR primarily detected two paramagnetic species in black soybean. These two different radical species were assigned as stable organic radical and Mn 2+  species based on the g values and hyperfine structures. The signal from the stable radical was noted at g ≈ 2.00 and was relatively strong and stable. Subsequent noninvasive two-dimensional (2D) EPRI of the radical present in black soybean revealed that the stable radical was primarily located in the pigmented region of the soybean coat, with very few radicals observed in the soybean cotyledon (interior). Pigments extracted from black soybean were analyzed using HPLC. The major compound was found to be cyanidin-3-glucoside. Multi-EPR and HPLC results indicate that the stable radical was only found within the pigmented region of the soybean coat, and it could be cyanidin-3-glucoside or an oxidative decomposition product.

Influence of fertilizer on seed production in Allegheny hardwood stands

Treesearch

John C. Bjorkbom; L.R. Auchmoody; Donald E. Dorn

1979-01-01

Fertilizers applied in spring can stimulate production of black cherry and red maple seeds in Allegheny hardwood stands. Increased seed production begins in the year after application, but lasts only about 2 years. However, fertilizers do not increase seed production of individual black cherry trees that have a history of poor production, and they do not eliminate seed...

Physicochemical properties of water-soluble polysaccharides from black cumin seeds.

PubMed

Trigui, Ines; Yaich, Héla; Sila, Assaâd; Cheikh-Rouhou, Salma; Bougatef, Ali; Blecker, Christophe; Attia, Hamadi; Ayadi, M A

2018-06-01

In the present work, water-soluble polysaccharides were isolated from black cumin seeds. Polysaccharides were characterized by their carbohydrate composition, molecular weight, thermal stability and by FTIR, NMR spectroscopy and X-ray diffraction. The surface, the functional and the antioxidant properties of black cumin water-soluble polysaccharides (BCWSP) were also investigated. BCWSP consisted mainly of galacturonic acid (30.20%), glucuronic acid (17.66%) and neutral sugar (22.99%). BCWSP was composed of high peak molecular weight. The FTIR spectrum obtained for BCWSP showed two most important absorptions, at 1659 and 1085 cm -1 , which corresponded to COO - of uronic acids and pyranose form, respectively. NMR spectroscopy data suggested that the BCWSP is probably a rhamnogalacturonan backbone with galactan and arabinan side chains. X-ray pattern revealed the semi-crystalline behavior of BCWSP. WHC and OHC of BCWSP were relatively high and varied with temperatures. The polysaccharide zeta potential was greatly affected by pH. Results indicated that the decrease of surface tension has influenced foaming and emulsifying capacities. The DPPH radical scavenging activity of the BCWSP was 63.25% at 1 mg/mL. The BCWSP displayed moderate reductive, β carotene bleaching and chelating abilities. Overall, our results suggested that BCWSP could be used as alternative additives in food and non-food products. Copyright © 2017. Published by Elsevier B.V.

Production of maize tortillas and cookies from nixtamalized flour enriched with anthocyanins, flavonoids and saponins extracted from black bean (Phaseolus vulgaris) seed coats.

PubMed

Chávez-Santoscoy, Rocio A; Gutiérrez-Uribe, Janet A; Serna-Saldivar, Sergio O; Perez-Carrillo, Esther

2016-02-01

Ethanolic extract from black beans coat is a source of flavonoids, saponins and antocyanins. Nixtamalized maize flours (NF) are used for the preparation of products such as tortillas, tortillas chips, cookies among others. The objective of this research was to study the effect on textural parameters and color after adding flavonoids, saponins and anthocyanins from black bean seed coat in NF used for the production of tortillas and gluten-free cookies. Furthermore, the retention of bioactive compounds after tortilla and gluten-free-cookie preparation was assessed. Ethanolic extracts of black bean seed coats were added (3g/kg or 7 g/kg) to NF in order to prepare corn tortillas and gluten free cookies characterized in terms of dimensions, color and texture. Addition of 7 g/kg affected the color of cookies and tortillas without effect on texture and dimensions. It was possible to retain more than 80% and 60% of bioactives into baked tortillas and cookies, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Black soybean seed coat extract ameliorates hyperglycemia and insulin sensitivity via the activation of AMP-activated protein kinase in diabetic mice.

PubMed

Kurimoto, Yuta; Shibayama, Yuki; Inoue, Seiya; Soga, Minoru; Takikawa, Masahito; Ito, Chiaki; Nanba, Fumio; Yoshida, Tadashi; Yamashita, Yoko; Ashida, Hitoshi; Tsuda, Takanori

2013-06-12

Black soybean seed coat has abundant levels of polyphenols such as anthocyanins (cyanidin 3-glucoside; C3G) and procyanidins (PCs). This study found that dietary black soybean seed coat extract (BE) ameliorates hyperglycemia and insulin sensitivity via the activation of AMP-activated protein kinase (AMPK) in type 2 diabetic mice. Dietary BE significantly reduced blood glucose levels and enhanced insulin sensitivity. AMPK was activated in the skeletal muscle and liver of diabetic mice fed BE. This activation was accompanied by the up-regulation of glucose transporter 4 in skeletal muscle and the down-regulation of gluconeogenesis in the liver. These changes resulted in improved hyperglycemia and insulin sensitivity in type 2 diabetic mice. In vitro studies using L6 myotubes showed that C3G and PCs significantly induced AMPK activation and enhanced glucose uptake into the cells.

Rapid growth of seed black holes in the early universe by supra-exponential accretion.

PubMed

Alexander, Tal; Natarajan, Priyamvada

2014-09-12

Mass accretion by black holes (BHs) is typically capped at the Eddington rate, when radiation's push balances gravity's pull. However, even exponential growth at the Eddington-limited e-folding time t(E) ~ few × 0.01 billion years is too slow to grow stellar-mass BH seeds into the supermassive luminous quasars that are observed when the universe is 1 billion years old. We propose a dynamical mechanism that can trigger supra-exponential accretion in the early universe, when a BH seed is bound in a star cluster fed by the ubiquitous dense cold gas flows. The high gas opacity traps the accretion radiation, while the low-mass BH's random motions suppress the formation of a slowly draining accretion disk. Supra-exponential growth can thus explain the puzzling emergence of supermassive BHs that power luminous quasars so soon after the Big Bang. Copyright © 2014, American Association for the Advancement of Science.

Formative Assessment Probes: Seeds in a Bag

ERIC Educational Resources Information Center

Keeley, Page

2014-01-01

Many young children come to school with prior experiences planting seeds in a garden or in a pot, watering them, and seeing them grow. These early scientific investigations are designed to help children understand that seeds need water, something to grow in (such as soil), and the right temperature to sprout--if these conditions are met, a seed…

The efficacy of black cumin seed (Nigella sativa) oil and hypoglycemic drug combination to reduce HbA1c level in patients with metabolic syndrome risk

NASA Astrophysics Data System (ADS)

Rachman, P. N. R.; Akrom; Darmawan, E.

2017-11-01

Metabolic syndrome is a conditions caused by metabolic abnormalities include central obesity, atherogenic dyslipidemia, hypertension, and insulin resistance. HbA1c examination is required to study the long-term glycemic status and to prevent diabetic complications of metabolic syndrome. The purpose of this study is to determine the efficacy of black cumin seed (Nigella sativa) oil and hypoglycemic drug combination to reduce HbA1c level in patients with metabolic syndrome risk. This research performed using an experimental randomized single - blind controlled trial design. A total of 99 outpatients at the Jetis I Public Health Center, Yogyakarta, Indonesia with metabolic syndrome risk were divided into three groups: The control group received placebo and two treatment groups received black seed oil orally at dose of 1.5 mL/day and 3 mL/day, respectively, for 20 days. The clinical conditions such as blood pressure, pulse rate, BMI, blood glucose serum and HbA1c levels were examined on day 0 and 21. The results obtained were analyzed with one-way ANOVA test. The mean of HbA1c levels of all groups before treatment was higher than the normal values and there was no significant difference in HbA1c value on day 0. Administration of 1.5 and 3 mL/day of black seed oil for 20 days decreased (p<0.05) HbA1c levels. It can be concluded that administration of black cumin seed oil and hypoglycemic drug combination for 20 days in patients at risk of metabolic syndrome may reduce to HbA1c levels.

Screening and identification of major phytochemical compounds in seeds, sprouts and leaves of Tuscan black kale Brassica oleracea (L.) ssp acephala (DC) var. sabellica L.

PubMed

Giorgetti, Lucia; Giorgi, Gianluca; Cherubini, Edoardo; Gervasi, Pier Giovanni; Della Croce, Clara Maria; Longo, Vincenzo; Bellani, Lorenza

2018-07-01

We report the spectrophotometric determination of total polyphenols, flavonoids, glucosinolates and antioxidant activity in seeds, seedlings and leaves of Tuscan black kale. The highest content of phytochemicals was observed in 10 days sprouts and antioxidant activity was maximum in 2, 4 days seedlings. Identification and characterisation of phytochemicals were performed by mass spectrometry (MS), high resolution and tandem MS with electrospray ionisation mode. Low-molecular-weight metabolites were evidenced in seeds while metabolites at high m/z range were detected in cotyledons and leaves. MS spectra evidenced different phenolic compounds (flavonoid caffeoyl glucose, hydroxycinnamic acid sinapine) and glucosinolates (glucoerucin, glucobrassicin and glucoraphanin) in function of developmental stage; galactolipids ω3 and ω6 were observed in leaves. Identification of stages with the highest phytochemicals content encourages the consumption of black kale sprouts and young leaves. Our research can support food and pharmaceutical industries for production of health promoting products from black kale.

THE FORMATION OF SUPERMASSIVE BLACK HOLES FROM LOW-MASS POP III SEEDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whalen, Daniel J.; Fryer, Chris L.

2012-09-01

The existence of 10{sup 9} M{sub Sun} black holes (BHs) in massive galaxies by z {approx} 7 is one of the great unsolved mysteries in cosmological structure formation. One theory argues that they originate from the BHs of Pop III stars at z {approx} 20 and then accrete at the Eddington limit down to the epoch of reionization, which requires that they have constant access to rich supplies of fuel. Because early numerical simulations suggested that Pop III stars were {approx}>100 M{sub Sun }, the supermassive black hole (SMBH) seeds considered up to now were 100-300 M{sub Sun }. However,more » there is a growing numerical and observational consensus that some Pop III stars were tens of solar masses, not hundreds, and that 20-40 M{sub Sun} BHs may have been much more plentiful at high redshift. However, we find that natal kicks imparted to 20-40 M{sub Sun} Pop III BHs during formation eject them from their halos and hence their fuel supply, precluding them from Eddington-limit growth. Consequently, SMBHs are far less likely to form from low-mass Pop III stars than from very massive ones.« less

Germination of dimorphic seeds of the desert annual halophyte Suaeda aralocaspica (Chenopodiaceae), a C4 plant without Kranz anatomy.

PubMed

Wang, Lei; Huang, Zhenying; Baskin, Carol C; Baskin, Jerry M; Dong, Ming

2008-11-01

Suaeda aralocaspica is a C4 summer annual halophyte without Kranz anatomy that is restricted to the deserts of central Asia. It produces two distinct types of seeds that differ in colour, shape and size. The primary aims of the present study were to compare the dormancy and germination characteristics of dimorphic seeds of S. aralocaspica and to develop a conceptual model of their dynamics. Temperatures simulating those in the natural habitat of S. aralocaspica were used to test for primary dormancy and germination behaviour of fresh brown and black seeds. The effects of cold stratification, gibberellic acid, seed coat scarification, seed coat removal and dry storage on dormancy breaking were tested in black seeds. Germination percentage and recovery responses of brown seeds, non-treated black seeds and 8-week cold-stratified black seeds to salt stress were tested. Brown seeds were non-dormant, whereas black seeds had non-deep Type 2 physiological dormancy (PD). Germination percentage and rate of germination of brown seeds and of variously pretreated black seeds were significantly higher than those of non-pretreated black seeds. Exposure of seeds to various salinities had significant effects on germination, germination recovery and induction into secondary dormancy. A conceptual model is presented that ties these results together and puts them into an ecological context. The two seed morphs of S. aralocaspica exhibit distinct differences in dormancy and germination characteristics. Suaeda aralocaspica is the first cold desert halophyte for which non-deep Type 2 PD has been documented.

Direct seeding for forestation

Treesearch

Walter H. Davidson

1980-01-01

Direct seeding, an attractive alternative to planting, is not a simple method of forestation. Past experiences show far more failures than successes. Well documented procedures must be followed to insure any degree of success. In general, conifers have given the best results. Black walnut and black locust are notable exceptions. Current research suggests that other...

ERRATUM: In vivo evaluation of a neural stem cell-seeded prosthesis In vivo evaluation of a neural stem cell-seeded prosthesis

NASA Astrophysics Data System (ADS)

Purcell, E. K.; Seymour, J. P.; Yandamuri, S.; Kipke, D. R.

2009-08-01

In the published article, an error was made in figure 5. Specifically, the three-month, NSC-seeded image is a duplicate of the six-week image, and the one-day, probe alone image is a duplicate of the three-month image. The corrected figure is reproduced below. Figure 5 Figure 5. Glial encapsulation of each probe condition over the 3 month time course. Ox-42 labeled microglia and GFAP labeled astrocytes are shown. Images are taken from probes implanted in the same animal at each time point. NSC seeding was associated with reduced non-neuronal density at 1 day post-implantation in comparison to alginate coated probes and at the 1 week time point in comparison to untreated probes (P < 0.001). Glial activation is at its overall peak 1 week after insertion. A thin encapsulation layer surrounds probes at the 6 week and 3 month time points, with NSC-seeded probes having the greatest surrounding non-neuronal density P < 0.001). Interestingly, microglia appeared to have a ramified, or `surveilling', morphology surrounding a neural stem cell-alginate probe initially, whereas activated cells with an amoeboid structure were found near an alginate probe in the same hemisphere of one animal (left panels).

7 CFR 201.58a - Indistinguishable seeds.

Code of Federal Regulations, 2013 CFR

2013-01-01

... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... enough test solution to cover the seeds. Seeds coats of yellow sweetclover will begin to stain dark brown...) Calculation of results: Count the number of seeds which stain dark brown or black and divide by the total...

7 CFR 201.58a - Indistinguishable seeds.

Code of Federal Regulations, 2012 CFR

2012-01-01

... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... enough test solution to cover the seeds. Seeds coats of yellow sweetclover will begin to stain dark brown...) Calculation of results: Count the number of seeds which stain dark brown or black and divide by the total...

7 CFR 201.58a - Indistinguishable seeds.

Code of Federal Regulations, 2011 CFR

2011-01-01

... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... enough test solution to cover the seeds. Seeds coats of yellow sweetclover will begin to stain dark brown...) Calculation of results: Count the number of seeds which stain dark brown or black and divide by the total...

7 CFR 201.58a - Indistinguishable seeds.

Code of Federal Regulations, 2014 CFR

2014-01-01

... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... enough test solution to cover the seeds. Seeds coats of yellow sweetclover will begin to stain dark brown...) Calculation of results: Count the number of seeds which stain dark brown or black and divide by the total...

Dark Candles of the Universe: Black Hole Observations

NASA Astrophysics Data System (ADS)

Aykutalp, Aycin

2016-03-01

In 1916, when Karl Schwarzschild solved the Einstein field equations of general relativity for a spherically symmetric, non-rotating mass no one anticipated the impact black holes would have on astrophysics. I will review the main formation channels for black hole seeds and their evolution through cosmic time. In this, emphasis will be placed on the observational diagnostics of astrophysical black holes and their role on the assembly of galaxy formation and evolution. I then review how these observations put constrain on the seed black hole formation theories. Finally, I present an outlook for how future observations can shed light on our understanding of black holes. This work is supported by NSF Grant AST-1333360.

Seeds in Flight

ERIC Educational Resources Information Center

Martin, Willard K.

1978-01-01

Discussed are the seed dispersal mechanisms of six different plants: big-leaf maple, pincushion tree, tree of heaven, squirting cucumber, digger pine, and bull thistle. Elaborate color and black-and-white drawings illustrate the text. (MA)

Effect of Allelochemicals from Leaf Leachates of Gmelina arborea on Inhibition of Some Essential Seed Germination Enzymes in Green Gram, Red Gram, Black Gram, and Chickpea.

PubMed

Madhan Shankar, Ramakrishnan; Veeralakshmi, Shanmugham; Sirajunnisa, Abdul Razack; Rajendran, Ramasamy

2014-01-01

The present work focused on identification of allelochemicals from the leaf leachates of Gmelina arborea and analyzing its influence on the germination of red gram, green gram, black gram, and chickpea in terms of the levels of some important germination enzymes like acid phosphatase, catalase, peroxidase, and amylase. The study showed that allelopathic effects were more predominant in chickpea with 80% followed by red gram, green gram, and black gram where the inhibition ranged between 26% and 75%. The vigor index in the seed lots is also considerably reduced. Total chlorophyll content was also reduced by allelopathic effect in all treated seeds ranging between 0.7 and 7.5 μg/g dry weight. The effect of allelochemicals drastically reduced the relative water content in red gram followed by the other seed lots. The total protein content varied considerably in the control and the treated seed lots. Allelochemicals inhibited the expression and activity of the enzymes required for efficient germination. The present study also threw limelight on the effective use of this tree, wherein planting this tree amidst pulse related herb plantations could affect the growth of the economically viable plants, but this tree can very well adapt to diversified soil conditions and rainfall zones.

Effect of Allelochemicals from Leaf Leachates of Gmelina arborea on Inhibition of Some Essential Seed Germination Enzymes in Green Gram, Red Gram, Black Gram, and Chickpea

PubMed Central

Madhan Shankar, Ramakrishnan; Veeralakshmi, Shanmugham; Rajendran, Ramasamy

2014-01-01

The present work focused on identification of allelochemicals from the leaf leachates of Gmelina arborea and analyzing its influence on the germination of red gram, green gram, black gram, and chickpea in terms of the levels of some important germination enzymes like acid phosphatase, catalase, peroxidase, and amylase. The study showed that allelopathic effects were more predominant in chickpea with 80% followed by red gram, green gram, and black gram where the inhibition ranged between 26% and 75%. The vigor index in the seed lots is also considerably reduced. Total chlorophyll content was also reduced by allelopathic effect in all treated seeds ranging between 0.7 and 7.5 μg/g dry weight. The effect of allelochemicals drastically reduced the relative water content in red gram followed by the other seed lots. The total protein content varied considerably in the control and the treated seed lots. Allelochemicals inhibited the expression and activity of the enzymes required for efficient germination. The present study also threw limelight on the effective use of this tree, wherein planting this tree amidst pulse related herb plantations could affect the growth of the economically viable plants, but this tree can very well adapt to diversified soil conditions and rainfall zones. PMID:27350959

Seed production and advance regeneration in Allegheny hardwood forests

Treesearch

John C. Bjorkbom

1979-01-01

The production of flowers and seeds of black cherry, red maple, sugar maple, and white ash and their relation to advance regeneration were observed from 1971 through 1976 on the Allegheny Plateau of northwestern Pennsylvania. There were good seed crops 1 year out of 2 for black cherry, 1 year out of 3 for red maple, and 1 year out of 6 for sugar maple. No white ash...

Probing the magnetic field structure in Sgr A* on Black Hole Horizon Scales with Polarized Radiative Transfer Simulations

NASA Astrophysics Data System (ADS)

Gold, Roman; McKinney, Jonathan; Johnson, Michael; Doeleman, Sheperd; Event Horizon Telescope Collaboration

2016-03-01

Accreting black holes (BHs) are at the core of relativistic astrophysics as messengers of the strong-field regime of General Relativity and prime targets of several observational campaigns, including imaging the black hole shadow in SagA* and M87 with the Event Horizon Telescope. I will present results from general-relativistic, polarized radiatiative transfer models for the inner accretion flow in Sgr A*. The models use time dependent, global GRMHD simulations of hot accretion flows including standard-and-normal-evolution (SANE) and magnetically arrested disks (MAD). I present comparisons of these synthetic data sets to the most recent observations with the Event Horizon Telescope and show how the data distinguishes the models and probes the magnetic field structure.

Chemopreventive activity of ellagitannins and their derivatives from black raspberry seeds on HT-29 colon cancer cells.

PubMed

Cho, Hyunnho; Jung, Hana; Lee, Heejae; Yi, Hae Chang; Kwak, Ho-kyung; Hwang, Keum Taek

2015-05-01

Black raspberry (BRB) seeds are a major waste product after fruit processing. The seeds are abundant in ellagitannins (ET), a class of hydrolysable tannins, which are hydrolyzed to ellagic acid (EA) and further metabolized to urolithin A (UA) and urolithin B (UB), known to be bioavailable in the colon and the prostate. In this study, the anti-cancer activities of these compounds were evaluated on HT-29 colon cancer cells. ET, EA, UA and UB inhibited the proliferation of the cancer cells. EA caused a slight, but significant cell cycle arrest at the G1 phase, and urolithins caused cell cycle arrest at the G2/M phase and upregulated p21 expression. Apoptotic cells were detected by Annexin V-FITC/PI assay when treated with the compounds. Disruption in mitochondrial membrane potential and activation of caspases 8 and 9 suggest that both extrinsic and intrinsic apoptotic pathways may be involved. Activation of caspase 3 and cleavage of PARP further confirmed the induction of the apoptosis. ET, EA, UA and UB showed anti-cancer activity by arresting the cell cycle and inducing apoptosis on HT-29 human colon cancer cells. This study suggests that the BRB seeds could be a potential source of anti-cancer ET.

Black soybean seed coat polyphenols prevent B(a)P-induced DNA damage through modulating drug-metabolizing enzymes in HepG2 cells and ICR mice.

PubMed

Zhang, Tianshun; Jiang, Songyan; He, Chao; Kimura, Yuki; Yamashita, Yoko; Ashida, Hitoshi

2013-04-15

Black soybean seed coat is a rich source of polyphenols that have been reported to have various physiological functions. The present study investigated the potential protective effects of polyphenolic extracts from black soybean seed coat on DNA damage in human hepatoma HepG2 cells and ICR mice. The results from micronucleus (MN) assay revealed that black soybean seed coat extract (BE) at concentrations up to 25μg/mL was non-genotoxic. It is noteworthy that BE (at 4.85μg/mL) and its main components, procyanidins (PCs) and cyanidin 3-glucoside (C3G), at 10μM significantly reduced the genotoxic effect induced by benzo[a]pyrene [B(a)P]. To obtain insights into the underlying mechanism, we investigated BE and its main components on drug-metabolizing enzyme expression. The results of this study demonstrate that BE and its main components, PCs and C3G, down-regulated B(a)P-induced cytochrome P4501A1 (CYP1A1) expression by inhibiting the transformation of aryl hydrocarbon receptor. Moreover, they increased expression of detoxifying defense enzymes, glutathione S-transferases (GSTs) via increasing the binding of nuclear factor-erythroid-2-related factor 2 to antioxidant response elements. Collectively, we found that PCs and C3G, which are the main active compounds of BE, down-regulated CYP1A1 and up-regulated GST expression to protect B(a)P-induced DNA damage in HepG2 cells and ICR mice effectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of Black Pepper (Piper Nigrum), Turmeric Powder (Curcuma Longa) and Coriander Seeds (Coriandrum Sativum) and Their Combinations as Feed Additives on Growth Performance, Carcass Traits, Some Blood Parameters and Humoral Immune Response of Broiler Chickens

PubMed Central

Abou-Elkhair, R.; Ahmed, H. A.; Selim, S.

2014-01-01

Different herbs and spices have been used as feed additives for various purposes in poultry production. This study was conducted to assess the effect of feed supplemented with black pepper (Piper nigrum), turmeric powder (Curcuma longa), coriander seeds (Coriandrum sativum) and their combinations on the performance of broilers. A total of 210 (Cobb) one-d-old chicks were divided into seven groups of 30 birds each. The treatments were: a control group received no supplement, 0.5% black pepper (T1), 0.5% turmeric powder (T2), 2% coriander seeds (T3), a mixture of 0.5% black pepper and 0.5% turmeric powder (T4), a mixture of 0.5% black pepper and 2% coriander seed (T5), and a mixture of 0.5% black pepper, 0.5% turmeric powder and 2% coriander seeds (T6). Higher significant values of body weight gain during the whole period of 5 weeks (p<0.001) were observed in broilers on T1, T3, T5, and T6 compared to control. Dietary supplements with T1, T2, T3, and T6 improved the cumulative G:F of broilers during the whole period of 5 weeks (p<0.001) compared with control. The dressing percentage and edible giblets were not influenced by dietary supplements, while higher values of relative weight of the liver (p<0.05) were obtained in T5 and T6 compared to control. The addition of feed supplements in T5 and T6 significantly increased serum total protein and decreased serum glucose, triglycerides and alkaline phosphatase concentrations compared with the control group (p<0.05). Broilers on T6 showed significant decrease in the serum glutamate pyruvate transaminase concentration (p<0.05) compared to control. The broilers having T5 and T6 supplemented feed had relatively greater antibody titre (p<0.001) at 35 d of age than control. It is concluded that dietary supplements with black pepper or coriander seeds or their combinations enhanced the performance and health status of broiler chickens. PMID:25050023

Effects of black pepper (piper nigrum), turmeric powder (curcuma longa) and coriander seeds (coriandrum sativum) and their combinations as feed additives on growth performance, carcass traits, some blood parameters and humoral immune response of broiler chickens.

PubMed

Abou-Elkhair, R; Ahmed, H A; Selim, S

2014-06-01

Different herbs and spices have been used as feed additives for various purposes in poultry production. This study was conducted to assess the effect of feed supplemented with black pepper (Piper nigrum), turmeric powder (Curcuma longa), coriander seeds (Coriandrum sativum) and their combinations on the performance of broilers. A total of 210 (Cobb) one-d-old chicks were divided into seven groups of 30 birds each. The treatments were: a control group received no supplement, 0.5% black pepper (T1), 0.5% turmeric powder (T2), 2% coriander seeds (T3), a mixture of 0.5% black pepper and 0.5% turmeric powder (T4), a mixture of 0.5% black pepper and 2% coriander seed (T5), and a mixture of 0.5% black pepper, 0.5% turmeric powder and 2% coriander seeds (T6). Higher significant values of body weight gain during the whole period of 5 weeks (p<0.001) were observed in broilers on T1, T3, T5, and T6 compared to control. Dietary supplements with T1, T2, T3, and T6 improved the cumulative G:F of broilers during the whole period of 5 weeks (p<0.001) compared with control. The dressing percentage and edible giblets were not influenced by dietary supplements, while higher values of relative weight of the liver (p<0.05) were obtained in T5 and T6 compared to control. The addition of feed supplements in T5 and T6 significantly increased serum total protein and decreased serum glucose, triglycerides and alkaline phosphatase concentrations compared with the control group (p<0.05). Broilers on T6 showed significant decrease in the serum glutamate pyruvate transaminase concentration (p<0.05) compared to control. The broilers having T5 and T6 supplemented feed had relatively greater antibody titre (p<0.001) at 35 d of age than control. It is concluded that dietary supplements with black pepper or coriander seeds or their combinations enhanced the performance and health status of broiler chickens.

NEAR-EXTREMAL BLACK HOLES AS INITIAL CONDITIONS OF LONG GRB SUPERNOVAE AND PROBES OF THEIR GRAVITATIONAL WAVE EMISSION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Putten, Maurice H. P. M.

2015-09-01

Long gamma-ray bursts (GRBs) associated with supernovae and short GRBs with extended emission (SGRBEE) from mergers are probably powered by black holes as a common inner engine, as their prompt GRB emission satisfies the same Amati correlation in the E{sub p,i}–E{sub iso} plane. We introduce modified Bardeen equations to identify hyper-accretion driving newly formed black holes in core-collapse supernovae to near-extremal spin as a precursor to prompt GRB emission. Subsequent spin-down is observed in the BATSE catalog of long GRBs. Spin-down provides a natural unification of long durations associated with the lifetime of black hole spin for normal long GRBsmore » and SGRBEEs, given the absence of major fallback matter in mergers. The results point to major emissions unseen in high frequency gravitational waves. A novel matched filtering method is described for LIGO–Virgo and KAGRA broadband probes of nearby core-collapse supernovae at essentially maximal sensitivity.« less

Patterns of Cross-Continental Variation in Tree Seed Mass in the Canadian Boreal Forest

PubMed Central

Liu, Jushan; Bai, Yuguang; Lamb, Eric G.; Simpson, Dale; Liu, Guofang; Wei, Yongsheng; Wang, Deli; McKenney, Daniel W.; Papadopol, Pia

2013-01-01

Seed mass is an adaptive trait affecting species distribution, population dynamics and community structure. In widely distributed species, variation in seed mass may reflect both genetic adaptation to local environments and adaptive phenotypic plasticity. Acknowledging the difficulty in separating these two aspects, we examined the causal relationships determining seed mass variation to better understand adaptability and/or plasticity of selected tree species to spatial/climatic variation. A total of 504, 481 and 454 seed collections of black spruce (Picea mariana (Mill.) B.S.P.), white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb) across the Canadian Boreal Forest, respectively, were selected. Correlation analyses were used to determine how seed mass vary with latitude, longitude, and altitude. Structural Equation Modeling was used to examine how geographic and climatic variables influence seed mass. Climatic factors explained a large portion of the variation in seed mass (34, 14 and 29%, for black spruce, white spruce and jack pine, respectively), indicating species-specific adaptation to long term climate conditions. Higher annual mean temperature and winter precipitation caused greater seed mass in black spruce, but annual precipitation was the controlling factor for white spruce. The combination of factors such as growing season temperature and evapotranspiration, temperature seasonality and annual precipitation together determined seed mass of jack pine. Overall, sites with higher winter temperatures were correlated with larger seeds. Thus, long-term climatic conditions, at least in part, determined spatial variation in seed mass. Black spruce and Jack pine, species with relatively more specific habitat requirements and less plasticity, had more variation in seed mass explained by climate than did the more plastic species white spruce. As traits such as seed mass are related to seedling growth and survival, they potentially

Signatures of primordial black hole dark matter

NASA Astrophysics Data System (ADS)

Belotsky, K. M.; Dmitriev, A. E.; Esipova, E. A.; Gani, V. A.; Grobov, A. V.; Khlopov, M. Yu.; Kirillov, A. A.; Rubin, S. G.; Svadkovsky, I. V.

2014-11-01

The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro-world and mechanisms of its symmetry breaking. In the early Universe heavy metastable particles can dominate, leaving primordial black holes (PBHs) after their decay, as well as the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which massive black holes (BHs) and/or their clusters can originate. PBHs can be formed in such transitions within a narrow interval of masses about 1017g and, avoiding severe observational constraints on PBHs, can be a candidate for the dominant form of dark matter. PBHs in this range of mass can give solution of the problem of reionization in the Universe at the redshift z 5-10. Clusters of massive PBHs can serve as a nonlinear seeds for galaxy formation, while PBHs evaporating in such clusters can provide an interesting interpretation for the observations of point-like gamma-ray sources. Analysis of possible PBH signatures represents a universal probe for super-high energy physics in the early Universe in studies of indirect effects of the dark matter.

The origin of seed photons for Comptonization in the black hole binary Swift J1753.5-0127

NASA Astrophysics Data System (ADS)

Kajava, J. J. E.; Veledina, A.; Tsygankov, S.; Neustroev, V.

2016-06-01

Aims: The black hole binary Swift J1753.5-0127 is providing a unique data set to study accretion flows. Various investigations of this system and of other black holes have not, however, led to an agreement on the accretion flow geometry or on the seed photon source for Comptonization during different stages of X-ray outbursts. We place constraints on these accretion flow properties by studying long-term spectral variations of this source. Methods: We performed phenomenological and self-consistent broad band spectral modeling of Swift J1753.5-0127 using quasi-simultaneous archived data from INTEGRAL/ISGRI, Swift/UVOT/XRT/BAT, RXTE/PCA/HEXTE, and MAXI/GSC instruments. Results: We identify a critical flux limit, F ~ 1.5 × 10-8 erg cm-2 s-1, and show that the spectral properties of Swift J1753.5-0127 are markedly different above and below this value. Above the limit, during the outburst peak, the hot medium seems to intercept roughly 50 percent of the disk emission. Below it, in the outburst tail, the contribution of the disk photons reduces significantly and the entire spectrum from the optical to X-rays can be produced by a synchrotron-self-Compton mechanism. The long-term variations in the hard X-ray spectra are caused by erratic changes of the electron temperatures in the hot medium. Thermal Comptonization models indicate unreasonably low hot medium optical depths during the short incursions into the soft state after 2010, suggesting that non-thermal electrons produce the Comptonized tail in this state. The soft X-ray excess, likely produced by the accretion disk, shows peculiarly stable temperatures for over an order of magnitude changes in flux. Conclusions: The long-term spectral trends of Swift J1753.5-0127 are likely set by variations of the truncation radius and a formation of a hot, quasi-spherical inner flow in the vicinity of the black hole. In the late outburst stages, at fluxes below the critical limit, the source of seed photons for Comptonization is

Prospects for Probing Strong Gravity with a Pulsar-Black Hole System

NASA Technical Reports Server (NTRS)

Wex, N.; Liu, K.; Eatough, R. P.; Kramer, M.; Cordes, J. M.; Lazio, T. J. W.

2012-01-01

The discovery of a pulsar (PSR) in orbit around a black hole (BH) is expected to provide a superb new probe of relativistic gravity and BH properties. Apart from a precise mass measurement for the BH, one could expect a clean verification of the dragging of space-time caused by the BH spin. In order to measure the quadrupole moment of the BH for testing the no-hair theorem of general relativity (GR), one has to hope for a sufficiently massive BH. In this respect, a PSR orbiting the super-massive BH in the center of our Galaxy would be the ultimate laboratory for gravity tests with PSRs. But even for gravity theories that predict the same properties for BHs as GR, a PSR-BH system would constitute an excellent test system, due to the high grade of asymmetry in the strong field properties of these two components. Here we highlight some of the potential gravity tests that one could expect from different PSR-BH systems.

Looking for early black holes signatures in the anisotropies of Cosmic backgrounds

NASA Astrophysics Data System (ADS)

Cappelluti, Nico

2016-04-01

We currently do not know how Super Massive Black Holes are seeded and grow to form the observed massive QSO at z~7. This is puzzling, because at that redshift the Universe was still too young to allow the growth of such massive black holes from stellar remnant black hole seeds. Theoretical models, taking into account the paucity of metals in the early Universe, explain this by invoking the formation of massive black holes seeds at z>10 as Direct Collapse Black holes of remnants of dead POPIII stars. As of today we cannot claim any detection of any high-z (z>7) black hole in their early stage of life. However, our recent measures of the arcminute scale joint fluctuations of the Cosmic X-ray Background and the Cosmic Infrared Background by Chandra and Spitzer can be explained by a population of highly absorbed z>10 Direct Collapse Black Holes.I will review the recent discoveries obtained with different instruments and by different teams and critically discuss these findings and the interpretations.

Bright vigorous winds as signposts of supermassive black hole birth

NASA Astrophysics Data System (ADS)

Fiacconi, Davide; Rossi, Elena M.

2016-01-01

The formation of supermassive black holes is still an outstanding question. In the quasi-star scenario, black hole seeds experience an initial super-Eddington growth, that in less than a million years may leave a 104-105 M⊙ black hole at the centre of a protogalaxy at z ˜ 20-10. Super-Eddington accretion, however, may be accompanied by vigorous mass-loss that can limit the amount of mass that reaches the black hole. In this paper, we critically assess the impact of radiative driven winds, launched from the surface of the massive envelopes from which the black hole accretes. Solving the full wind equations coupled with the hydrostatic structure of the envelope, we find mass outflows with rates between a few tens and 104 M⊙ yr-1, mainly powered by advection luminosity within the outflow. We therefore confirm the claim by Dotan et al. that mass losses can severely affect the black hole seed early growth within a quasi-star. In particular, seeds with mass >104 M⊙ can only form within mass reservoirs ≳107 M⊙, unless they are refilled at huge rates (≳100 M⊙ yr-1). This may imply that only very massive haloes (>109 M⊙) at those redshifts can harbour massive seeds. Contrary to previous claims, these winds are expected to be relatively bright (1044-1047 erg s-1), blue (Teff ˜ 8000 K) objects, that while eluding the Hubble Space Telescope, could be observed by the James Webb Space Telescope.

Real-time control of divertor detachment in H-mode with impurity seeding using Langmuir probe feedback in JET-ITER-like wall

NASA Astrophysics Data System (ADS)

Guillemaut, C.; Lennholm, M.; Harrison, J.; Carvalho, I.; Valcarcel, D.; Felton, R.; Griph, S.; Hogben, C.; Lucock, R.; Matthews, G. F.; Perez Von Thun, C.; Pitts, R. A.; Wiesen, S.; contributors, JET

2017-04-01

Burning plasmas with 500 MW of fusion power on ITER will rely on partially detached divertor operation to keep target heat loads at manageable levels. Such divertor regimes will be maintained by a real-time control system using the seeding of radiative impurities like nitrogen (N), neon or argon as actuator and one or more diagnostic signals as sensors. Recently, real-time control of divertor detachment has been successfully achieved in Type I ELMy H-mode JET-ITER-like wall discharges by using saturation current (I sat) measurements from divertor Langmuir probes as feedback signals to control the level of N seeding. The degree of divertor detachment is calculated in real-time by comparing the outer target peak I sat measurements to the peak I sat value at the roll-over in order to control the opening of the N injection valve. Real-time control of detachment has been achieved in both fixed and swept strike point experiments. The system has been progressively improved and can now automatically drive the divertor conditions from attached through high recycling and roll-over down to a user-defined level of detachment. Such a demonstration is a successful proof of principle in the context of future operation on ITER which will be extensively equipped with divertor target probes.

Gravitational waves at interferometer scales and primordial black holes in axion inflation

DOE Office of Scientific and Technical Information (OSTI.GOV)

García-Bellido, Juan; Peloso, Marco; Unal, Caner, E-mail: juan.garciabellido@uam.es, E-mail: peloso@physics.umn.edu, E-mail: unal@physics.umn.edu

We study the prospects of detection at terrestrial and space interferometers, as well as at pulsar timing array experiments, of a stochastic gravitational wave background which can be produced in models of axion inflation. This potential signal, and the development of these experiments, open a new window on inflation on scales much smaller than those currently probed with Cosmic Microwave Background and Large Scale Structure measurements. The sourced signal generated in axion inflation is an ideal candidate for such searches, since it naturally grows at small scales, and it has specific properties (chirality and non-gaussianity) that can distinguish it frommore » an astrophysical background. We study under which conditions such a signal can be produced at an observable level, without the simultaneous overproduction of scalar perturbations in excess of what is allowed by the primordial black hole limits. We also explore the possibility that scalar perturbations generated in a modified version of this model may provide a distribution of primordial black holes compatible with the current bounds, that can act as a seeds of the present black holes in the universe.« less

Direct Collapse to Supermassive Black Hole Seeds with Radiation Transfer: Cosmological Halos

NASA Astrophysics Data System (ADS)

Ardaneh, Kazem; Luo, Yang; Shlosman, Isaac; Nagamine, Kentaro; Wise, John H.; Begelman, Mitchell C.

2018-06-01

We have modeled direct collapse of a primordial gas within dark matter halos in the presence of radiative transfer, in high-resolution zoom-in simulations in a cosmological framework, down to the formation of the photosphere and the central object. Radiative transfer has been implemented in the flux-limited diffusion (FLD) approximation. Adiabatic models were run for comparison. We find that (a) the FLD flow forms an irregular central structure and does not exhibit fragmentation, contrary to adiabatic flow which forms a thick disk, driving a pair of spiral shocks, subject to Kelvin-Helmholtz shear instability forming fragments; (b) the growing central core in the FLD flow quickly reaches ˜10 M⊙ and a highly variable luminosity of 1038 - 1039 erg s-1, comparable to the Eddington luminosity. It experiences massive recurrent outflows driven by radiation force and thermal pressure gradients, which mix with the accretion flow and transfer the angular momentum outwards; and (c) the interplay between these processes and a massive accretion, results in photosphere at ˜10 AU. We conclude that in the FLD model (1) the central object exhibits dynamically insignificant rotation and slower than adiabatic temperature rise with density; (2) does not experience fragmentation leading to star formation, thus promoting the fast track formation of a supermassive black hole (SMBH) seed; (3) inclusion of radiation force leads to outflows, resulting in the mass accumulation within the central 10-3 pc, which is ˜100 times larger than characteristic scale of star formation. The inclusion of radiative transfer reveals complex early stages of formation and growth of the central structure in the direct collapse scenario of SMBH seed formation.

Strong Gravitational Lensing as a Probe of Gravity, Dark-Matter and Super-Massive Black Holes

NASA Astrophysics Data System (ADS)

Koopmans, L.V.E.; Barnabe, M.; Bolton, A.; Bradac, M.; Ciotti, L.; Congdon, A.; Czoske, O.; Dye, S.; Dutton, A.; Elliasdottir, A.; Evans, E.; Fassnacht, C.D.; Jackson, N.; Keeton, C.; Lasio, J.; Moustakas, L.; Meneghetti, M.; Myers, S.; Nipoti, C.; Suyu, S.; van de Ven, G.; Vegetti, S.; Wucknitz, O.; Zhao, H.-S.

Whereas considerable effort has been afforded in understanding the properties of galaxies, a full physical picture, connecting their baryonic and dark-matter content, super-massive black holes, and (metric) theories of gravity, is still ill-defined. Strong gravitational lensing furnishes a powerful method to probe gravity in the central regions of galaxies. It can (1) provide a unique detection-channel of dark-matter substructure beyond the local galaxy group, (2) constrain dark-matter physics, complementary to direct-detection experiments, as well as metric theories of gravity, (3) probe central super-massive black holes, and (4) provide crucial insight into galaxy formation processes from the dark matter point of view, independently of the nature and state of dark matter. To seriously address the above questions, a considerable increase in the number of strong gravitational-lens systems is required. In the timeframe 2010-2020, a staged approach with radio (e.g. EVLA, e-MERLIN, LOFAR, SKA phase-I) and optical (e.g. LSST and JDEM) instruments can provide 10^(2-4) new lenses, and up to 10^(4-6) new lens systems from SKA/LSST/JDEM all-sky surveys around ~2020. Follow-up imaging of (radio) lenses is necessary with moderate ground/space-based optical-IR telescopes and with 30-50m telescopes for spectroscopy (e.g. TMT, GMT, ELT). To answer these fundamental questions through strong gravitational lensing, a strong investment in large radio and optical-IR facilities is therefore critical in the coming decade. In particular, only large-scale radio lens surveys (e.g. with SKA) provide the large numbers of high-resolution and high-fidelity images of lenses needed for SMBH and flux-ratio anomaly studies.

Music from the heavens - gravitational waves from supermassive black hole mergers in the EAGLE simulations

NASA Astrophysics Data System (ADS)

Salcido, Jaime; Bower, Richard G.; Theuns, Tom; McAlpine, Stuart; Schaller, Matthieu; Crain, Robert A.; Schaye, Joop; Regan, John

2016-11-01

We estimate the expected event rate of gravitational wave signals from mergers of supermassive black holes that could be resolved by a space-based interferometer, such as the Evolved Laser Interferometer Space Antenna (eLISA), utilizing the reference cosmological hydrodynamical simulation from the EAGLE suite. These simulations assume a Lambda cold dark matter cosmogony with state-of-the-art subgrid models for radiative cooling, star formation, stellar mass loss, and feedback from stars and accreting black holes. They have been shown to reproduce the observed galaxy population with unprecedented fidelity. We combine the merger rates of supermassive black holes in EAGLE with the latest phenomenological waveform models to calculate the gravitational waves signals from the intrinsic parameters of the merging black holes. The EAGLE models predict ˜2 detections per year by a gravitational wave detector such as eLISA. We find that these signals are largely dominated by mergers between seed mass black holes merging at redshifts between z ˜ 2 and z ˜ 1. In order to investigate the dependence on the assumed black hole seed mass, we introduce an additional model with a black hole seed mass an order of magnitude smaller than in our reference model. We also consider a variation of the reference model where a prescription for the expected delays in the black hole merger time-scale has been included after their host galaxies merge. We find that the merger rate is similar in all models, but that the initial black hole seed mass could be distinguished through their detected gravitational waveforms. Hence, the characteristic gravitational wave signals detected by eLISA will provide profound insight into the origin of supermassive black holes and the initial mass distribution of black hole seeds.

Early growth of typical high-redshift black holes seeded by direct collapse

NASA Astrophysics Data System (ADS)

Latif, Muhammad A.; Volonteri, Marta; Wise, John H.

2018-06-01

Understanding the growth of high-redshift massive black holes (MBHs) is a problem of great astrophysical interest. The most luminous quasars at z > 6 are frequently observed but they represent only the tip of the iceberg as the majority of the low-luminosity active galactic nuclei (AGN) population remains undetected. In this study, we perform a radiation hydrodynamics cosmological simulation to study the growth of `normal' black holes in the high-redshift universe. In our simulation, we model the formation of Pop III and Pop II stars along with their chemical, mechanical, and radiative feedback. We consider both UV and X-ray emission from an accreting BH to simulate its radiative feedback. The selected halo has a mass of 3 × 10^{10} M_{⊙} at z = 7.5 and we turn on radiative feedback from a MBH seed of 10^5 M_{⊙} along with in situ star formation at z = 12 when the halo mass reaches well above the atomic cooling limit. We find that the MBH accretes only about 2200 M_{⊙} during 320 Myr and the average mass accretion on to the MBH is a few times 10^{-6} M_{⊙} yr^{-1}. Our results suggest that the stunted growth of MBH is a consequence of supernovae in tandem with MBH feedback which drive large outflows and evacuate the gas from MBH vicinity. This may explain why a population of low-luminosity AGN has not been detected so-far at z > 6; the large contrast between the star formation rate and the MBH accretion rate may make then hard to detect even in upcoming deep surveys.

The black hole symphony: probing new physics using gravitational waves.

PubMed

Gair, Jonathan R

2008-12-13

The next decade will very likely see the birth of a new field of astronomy as we become able to directly detect gravitational waves (GWs) for the first time. The existence of GWs is one of the key predictions of Einstein's theory of general relativity, but they have eluded direct detection for the last century. This will change thanks to a new generation of laser interferometers that are already in operation or which are planned for the near future. GW observations will allow us to probe some of the most exotic and energetic events in the Universe, the mergers of black holes. We will obtain information about the systems to a precision unprecedented in astronomy, and this will revolutionize our understanding of compact astrophysical systems. Moreover, if any of the assumptions of relativity theory are incorrect, this will lead to subtle, but potentially detectable, differences in the emitted GWs. Our observations will thus provide very precise verifications of the theory in an as yet untested regime. In this paper, I will discuss what GW observations could tell us about known and (potentially) unknown physics.

Tocopherol isomer pattern in serum and stool of human following consumption of black currant seed press residue administered in whole grain bread.

PubMed

Helbig, Dorit; Wagner, Andreas; Schubert, Rainer; Jahreis, Gerhard

2009-12-01

Serum gamma-tocopherol is thought to be associated with human health. The dietary influence of tocopherol and fibre-rich black currant seed press residue on serum and stool tocopherol concentration was investigated in a controlled human intervention study. Thirty-six women consumed bread enriched with black currant press residue (4 weeks). The resultant faecal and serum tocopherol concentrations were compared with those after a period consuming control bread without press residue and a normal baseline diet. Fibre intake and excretion, antioxidant capacity (TEAC), and vitamin C concentrations in serum and urine were also determined. Samples were obtained with a 5-day standardised diet at the end of each period. The press residue bread lead to significantly increased beta-, gamma-, delta- and total tocopherol intake, serum alpha-, beta-, gamma- and total tocopherol concentration (with and without lipid adjustment), fibre intake and urinary vitamin C concentration compared to control bread (P<0.05). Faecal excretion of total tocopherols and fibre increased compared to baseline (P<0.05). Fibre intake and excretion influence total tocopherol concentration in lipid-adjusted serum and in stool. The outstandingly high increase of serum gamma-tocopherol concentration through seed press residue consumption could be due to a presumed interruption of the enzymatic tocopherol degradation mechanism by bread constituents.

Late time cosmology with LISA: Probing the cosmic expansion with massive black hole binary mergers as standard sirens

NASA Astrophysics Data System (ADS)

Tamanini, Nicola

2017-05-01

This paper summarises the potential of the LISA mission to constrain the expansion history of the universe using massive black hole binary mergers as gravitational wave standard sirens. After briefly reviewing the concept of standard siren, the analysis and methodologies of Ref [1] are briefly outlined to show how LISA can be used as a cosmological probe, while a selection of results taken from Refs. [1, 2] is presented in order to estimate the power of LISA in constraining cosmological parameters.

Polyphenol content and antioxidant properties of colored soybean seeds from central Europe.

PubMed

Malenčić, Djordje; Cvejić, Jelena; Miladinović, Jegor

2012-01-01

The antioxidant activity and contents of various polyphenol classes in the seeds of seven soybean varieties of different seed color and one yellow seed cultivar, representing a reference genotype, were evaluated. Total polyphenols and tannins were determined after extraction of plant material with 70% aqueous acetone, and total flavonoids were extracted with methanol and acetic acid, whereas anthocyanins were extracted with 20% aqueous ethanol. In addition, isoflavone content and composition were determined using high-performance liquid chromatography analysis. Antioxidant activity of seed extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity assay. A positive linear correlation between antioxidant activity and contents of total polyphenols and anthocyanins was established. The highest antioxidant activity was observed in the extracts of black and brown varieties, which also showed high levels of all polyphenol classes examined. Yellow seed had the highest total isoflavone content (3.62 mg/g of dry material). The highest concentration of total daidzein was determined in black seeds (>2.0 mg/g of dry material), and the highest total glycitein and genistein contents occurred in the yellow cultivar (0.53 and 1.49 mg/g of dry material, respectively). According to our results, varieties of black and brown seeds could be of special interest not only for their large content of total polyphenols, ranging from 4.94 to 6.22 mg of gallic acid equivalents/g of dry material, but also for their high content of natural antioxidants such as anthocyanins.

The case for artificial black holes.

PubMed

Leonhardt, Ulf; Philbin, Thomas G

2008-08-28

The event horizon is predicted to generate particles from the quantum vacuum, an effect that bridges three areas of physics--general relativity, quantum mechanics and thermodynamics. The quantum radiation of real black holes is too feeble to be detectable, but black-hole analogues may probe several aspects of quantum black holes. In this paper, we explain in simple terms some of the motivations behind the study of artificial black holes.

Carry-over of Differential Salt Tolerance in Plants Grown from Dimorphic Seeds of Suaeda splendens

PubMed Central

Redondo-Gómez, Susana; Mateos-Naranjo, Enrique; Cambrollé, Jesús; Luque, Teresa; Figueroa, M. Enrique; Davy, Anthony J.

2008-01-01

Background and Aims Halophytic species often show seed dimorphism, where seed morphs produced by a single individual may differ in germination characteristics. Particular morphs are adapted to different windows of opportunity for germination in the seasonally fluctuating and heterogeneous salt-marsh environment. The possibility that plants derived from the two morphs may also differ physiologically has not been investigated previously. Methods Experiments were designed to investigate the germination characteristics of black and brown seed morphs of Suaeda splendens, an annual, C4 shrub of non-tidal, saline steppes. The resulting seedlings were transferred to hydroponic culture to investigate their growth and photosynthetic (PSII photochemistry and gas exchange) responses to salinity. Key Results Black seeds germinated at low salinity but were particularly sensitive to increasing salt concentrations, and strongly inhibited by light. Brown seeds were unaffected by light, able to germinate at higher salinities and generally germinated more rapidly. Ungerminated black seeds maintained viability for longer than brown ones, particularly at high salinity. Seedlings derived from both seed morphs grew well at high salinity (400 mol m−3 NaCl). However, seedlings derived from brown seeds performed poorly at low salinity, as reflected in relative growth rate, numbers of branches produced, Fv/Fm and net rate of CO2 assimilation. Conclusions The seeds most likely to germinate at high salinity in the Mediterranean summer (brown ones) retain a requirement for higher salinity as seedlings that might be of adaptive value. On the other hand, black seeds, which are likely to delay germination until lower salinity prevails, produce seedlings that are less sensitive to salinity. It is not clear why performance at low salinity, later in the life cycle, might have been sacrificed by the brown seeds, to achieve higher fitness at the germination stage under high salinity. Analyses of

Carry-over of differential salt tolerance in plants grown from dimorphic seeds of Suaeda splendens.

PubMed

Redondo-Gómez, Susana; Mateos-Naranjo, Enrique; Cambrollé, Jesús; Luque, Teresa; Figueroa, M Enrique; Davy, Anthony J

2008-07-01

Halophytic species often show seed dimorphism, where seed morphs produced by a single individual may differ in germination characteristics. Particular morphs are adapted to different windows of opportunity for germination in the seasonally fluctuating and heterogeneous salt-marsh environment. The possibility that plants derived from the two morphs may also differ physiologically has not been investigated previously. Experiments were designed to investigate the germination characteristics of black and brown seed morphs of Suaeda splendens, an annual, C(4) shrub of non-tidal, saline steppes. The resulting seedlings were transferred to hydroponic culture to investigate their growth and photosynthetic (PSII photochemistry and gas exchange) responses to salinity. Black seeds germinated at low salinity but were particularly sensitive to increasing salt concentrations, and strongly inhibited by light. Brown seeds were unaffected by light, able to germinate at higher salinities and generally germinated more rapidly. Ungerminated black seeds maintained viability for longer than brown ones, particularly at high salinity. Seedlings derived from both seed morphs grew well at high salinity (400 mol m(-3) NaCl). However, seedlings derived from brown seeds performed poorly at low salinity, as reflected in relative growth rate, numbers of branches produced, F(v)/F(m) and net rate of CO(2) assimilation. The seeds most likely to germinate at high salinity in the Mediterranean summer (brown ones) retain a requirement for higher salinity as seedlings that might be of adaptive value. On the other hand, black seeds, which are likely to delay germination until lower salinity prevails, produce seedlings that are less sensitive to salinity. It is not clear why performance at low salinity, later in the life cycle, might have been sacrificed by the brown seeds, to achieve higher fitness at the germination stage under high salinity. Analyses of adaptive syndromes associated with seed

Total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone.

PubMed

Rababah, Taha M; Hettiarachchy, Navam S; Horax, Ronny

2004-08-11

The total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone, were determined. Grape seed and green tea were analyzed for their phenolic constituents using high-performance liquid chromatography. The total phenolics of the plant extracts, determined by the Folin-Ciocalteu method, ranged from 24.8 to 92.5 mg of chlorogenic acid equivalent/g dry material. The antioxidant activities of methanolic extracts determined by conjugated diene measurement of methyl linoleate were 3.4-86.3%. The antioxidant activity of the extracts using chicken fat by an oxidative stability instrument (4.6-10.2 h of induction time) followed a similar trend in antioxidant activity as determined by the Folin-Ciocalteu method. Seven phenolics in grape seed and green tea extracts were identified that ranged from 15.38 to 1158.49 and 18.3 to 1087.02 mg/100 g of extract, respectively. Plant extracts such as green tea and grape seed extracts can be used to retard lipid oxidation in a variety of food products.

Detecting tidal disruption events of massive black holes in normal galaxies with the Einstein Probe

NASA Astrophysics Data System (ADS)

Yuan, W.; Komossa, S.; Zhang, C.; Feng, H.; Ling, Z.-X.; Zhao, D. H.; Zhang, S.-N.; Osborne, J. P.; O'Brien, P.; Willingale, R.; Lapington, J.

2016-02-01

Stars are tidally disrupted and accreted when they approach massive black holes (MBHs) closely, producing a flare of electromagnetic radiation. The majority of the (approximately two dozen) tidal disruption events (TDEs) identified so far have been discovered by their luminous, transient X-ray emission. Once TDEs are detected in much larger numbers, in future dedicated transient surveys, a wealth of new applications will become possible. Here, we present the proposed Einstein Probe mission, which is a dedicated time-domain soft X-ray all-sky monitor aiming at detecting X-ray transients including TDEs in large numbers. The mission consists of a wide-field micro-pore Lobster-eye imager (60° × 60°), and is designed to carry out an all-sky transient survey at energies of 0.5-4 keV. It will also carry a more sensitive telescope for X-ray follow-ups, and will be capable of issuing public transient alerts rapidly. Einstein Probe is expected to revolutionise the field of TDE research by detecting several tens to hundreds of events per year from the early phase of flares, many with long-term, well sampled lightcurves.

Phenolic content and antioxidant properties of seeds from different grape cultivars grown in Iran.

PubMed

Mirbagheri, Vasigheh Sadat; Alizadeh, Ebrahim; Yousef Elahi, Mostafa; Esmaeilzadeh Bahabadi, Sedigheh

2018-02-01

This study investigated the antioxidant activity and phenolic composition of seed extracts from three grape cultivars grown in Iran. Folin Ciocalteu method was used for the determination of the total phenolic contents and GC-MS was used for the analysis of phenolic compositions. 1,1-diphenyl-2-picrylhydrazyl (DPPH) method was used to evaluate the antioxidant activity. The highest and the lowest total phenolic contents of seed extract were found in the black and green grape, respectively. The content of individual phenols such as Frulic acid, Gentistic acid, Syringic acid, (+) Catechin, Chlorogenic acid and (-)- Epicatchin gallate was cultivars dependent. The antioxidant activity of the seed extracts ranged from 34.03% (Green) to 53.63% (Black). Generally, the Black grape seed extract with the total phenolic content (3 ± 0.01 mg tannic acid/g DM), DPPH (53.63 ± 0.34%), IC 50 and AEAC (7.41 and 16.92 mg/mL) showed the highest level of total antioxidant capacity.

Germination of dimorphic seeds of Suaeda aralocaspica in response to light and salinity conditions during and after cold stratification

PubMed Central

Wang, Hong-Ling; Tian, Chang-Yan

2017-01-01

Cold stratification is a requirement for seed dormancy breaking in many species, and thus it is one of the important factors for the regulation of timing of germination. However, few studies have examined the influence of various environmental conditions during cold stratification on subsequent germination, and no study has compared such effects on the performance of dormant versus non-dormant seeds. Seeds of halophytes in the cold desert might experience different light and salinity conditions during and after cold stratification. As such, dimorphic seeds (non-dormant brown seeds and black seeds with non-deep physiological dormancy) of Suaeda aralocaspica were cold stratified under different light (12 h light–12 h darkness photoperiod or continuous darkness) or salinity (0, 200 or 1,000 mmol L-1 NaCl) conditions for 20 or 40 days. Then stratified seeds were incubated under different light or salinity conditions at daily (12/12 h) temperature regime of 10:25 °C for 20 days. For brown seeds, cold stratification was also part of the germination period. In contrast, almost no black seeds germinated during cold stratification. The longer the cold stratification, the better the subsequent germination of black seeds, regardless of light or salinity conditions. Light did not influence germination of brown seeds. Germination of cold-stratified black seeds was inhibited by darkness, especially when they were stratified in darkness. With an increase in salinity at the stage of cold stratification or germination, germination percentages of both seed morphs decreased. Combinational pre-treatments of cold stratification and salinity did not increase salt tolerance of dimorphic seeds in germination phase. Thus, light and salinity conditions during cold stratification partly interact with these conditions during germination stage and differentially affect germination of dimorphic seeds of S. aralocaspica. PMID:28828266

Use of NMR spectroscopy and magnetic resonance imaging for discriminating Juglans nigra L. seeds

Treesearch

John A. Vozzo; J.M. Halloin; T.G. Cooper; E.J. Potechen

1996-01-01

Black walnut (JuglamnigraL.) seeds are large and require stratification for germination. However, many seeds fail to germinate following stratification. Radiography can be used to select empty seeds, but cannot determine which full seeds will germinate. The objective of this study was to determine if any discrimination could bc achieved through use...

Investigation of radical locations in various sesame seeds by CW EPR and 9-GHz EPR imaging.

PubMed

Nakagawa, K; Hara, H

2015-01-01

We investigated the location of radical in various sesame seeds using continuous-wave (CW) electron paramagnetic resonance (EPR) and 9-GHz EPR imaging. CW EPR detected persistent radicals (single line) for various sesame seeds. The EPR linewidth of black sesame seeds was narrower than that of the irradiated white sesame seeds. A very small signal was detected for the white sesame seeds. Two-dimensional (2D) imaging using a 9-GHz EPR imager showed that radical locations vary for various sesame seeds. The paramagnetic species in black sesame seeds were located on the seed coat (skin) and in the hilum region. The signal with the highest intensity was obtained from the hilum part. A very low-intensity image was observed for the white sesame seeds. In addition, the 2D imaging of the irradiated white sesame seeds showed that free radicals were located throughout the entire seed. For the first time, CW EPR and 9-GHz EPR imaging showed the exact location of radical species in various sesame seeds.

Polyphenol Content and Antioxidant Properties of Colored Soybean Seeds from Central Europe

PubMed Central

Cvejić, Jelena; Miladinović, Jegor

2012-01-01

Abstract The antioxidant activity and contents of various polyphenol classes in the seeds of seven soybean varieties of different seed color and one yellow seed cultivar, representing a reference genotype, were evaluated. Total polyphenols and tannins were determined after extraction of plant material with 70% aqueous acetone, and total flavonoids were extracted with methanol and acetic acid, whereas anthocyanins were extracted with 20% aqueous ethanol. In addition, isoflavone content and composition were determined using high-performance liquid chromatography analysis. Antioxidant activity of seed extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity assay. A positive linear correlation between antioxidant activity and contents of total polyphenols and anthocyanins was established. The highest antioxidant activity was observed in the extracts of black and brown varieties, which also showed high levels of all polyphenol classes examined. Yellow seed had the highest total isoflavone content (3.62 mg/g of dry material). The highest concentration of total daidzein was determined in black seeds (>2.0 mg/g of dry material), and the highest total glycitein and genistein contents occurred in the yellow cultivar (0.53 and 1.49 mg/g of dry material, respectively). According to our results, varieties of black and brown seeds could be of special interest not only for their large content of total polyphenols, ranging from 4.94 to 6.22 mg of gallic acid equivalents/g of dry material, but also for their high content of natural antioxidants such as anthocyanins. PMID:21861721

Flower production on clonal orchards at Oconto River Seed Orchard in Wisconsin

Treesearch

J.G. Murphy; R.G. Miller

1977-01-01

The Eastern Region, USDA Forest Service has been establishing and managing seed orchards to produce improved seed for the National Forests in the Lake States since 1969. This paper presents a review of the female flower production for the past 4 years in the white pine, white spruce, and black spruce clonal seed orchards.

Probing the Galactic Binary Black Hole Spin with Photon Timing

NASA Technical Reports Server (NTRS)

Kazanas, Demos

2007-01-01

It is generally considered that the X-ray emission in AGN and Galactic Black Hole Candidates is produced by flares above the surface of a geometrically thin optically thick accretion disk, which extends down to the Innermost Stable Circular Orbit (ISCO) of the black hole. We consider the influence of the black hole geometry on the light curves of these flares. To this end we follow a large number of photon orbits emitted impulsively in a locally isotropic fashion, at any phase of the disk orbit and examine their arrival times at infinity by an observer near the plane of the disk. We find out that the presence of the black hole spin induces a certain delay in the photon arrivals, as prograde photon orbits reach the observer on shorter (on the average) times than the retrograde ones. We form a histogram of the differences in photon time arrivals and we find that it exhibits several well defined peaks depending on the flare position and the black hole spin separated by $\\Delta t\\slmeq 30 M$, where M is the black hole mass. The peaks disappear as the spin parameter goes to zero, implying that one could in principle measure the value of the black hole spin with timing measurements of sufficiently high signal to noise ratio.

Probing the Galactic Binary Black Hole Spin with Photon Timing

NASA Technical Reports Server (NTRS)

Kazanas, Demosthenes

2007-01-01

It is generally considered that the X-ray emission in AGN and Galactic Black Hole Candidates is produced by flares above the surface of a geometrically thin optically thick accretion disk, which extends down to the Innermost Stable Circular Orbit (ISCO) of the black hole. We consider the influence of the black hole geometry on the light curves of these flares. To this end we follow a large number of photon orbits emitted impulsively in a locally isotropic fashion, at any phase of the disk orbit and examine their arrival times at infinity by an observer near the plane of the disk. We find out that the presence of the black hole spin induces a certain delay in the photon arrivals, as prograde photon orbits reach the observer on shorter (on the average) times than the retrograde ones. We form a histogram of the differences in photon time arrivals and we find that it exhibits several well defined peaks depending on the flare position and the black hole spin separated by $\\Delta t \\simeq 30 M$, where M is the black hole mass. The peaks disappear as the spin parameter goes to zero, implying that one could in principle measure the value of the black hole spin with timing measurements of sufficiently high signal to noise ratio.

Genotype × environment interaction on tocochromanol and plastochromanol-8 content in seeds of doubled haploids obtained from F1 hybrid black × yellow seeds of winter oilseed rape (Brassica napus L.).

PubMed

Siger, Aleksander; Michalak, Michał; Lembicz, Justyna; Nogala-Kałucka, Małgorzata; Cegielska-Taras, Teresa; Szała, Laurencja

2018-07-01

The aim of the study was to determine the effect of genotype × environment interaction on the levels of α-, β-, γ- and δ-tocopherol (α-T, β-T, γ-T and δ-T, respectively) and plastochromanol-8 (PC-8) in seeds of 17 doubled haploids (DHs) obtained from the F1 hybrid derived from crossing black (DH H 2 -26) × yellow (DH Z-114) seeds of winter oilseed rape. The content of tocopherols in the tested DH lines ranged from 415.6 to 540.1 mg kg -1 seeds, while PC-8 content ranged from 56.3 to 89.0 mg kg -1 seeds. The α-T/γ-T ratio reached a level of 0.78-1.29. Studies have shown that heritability for α-T, β-T, γ-T, total-T and PC-8 is mainly due to genotypic variation. For the δ-T homologue the level was dependent on environmental effect. The obtained DH lines population of oilseed rape is characterized by high heritability coefficients for α-T, β-T, γ-T, total-T and PC-8 levels, which indicates a greater influence of genotype than the environment on the content of these compounds. Among all studied doubled haploids, seven DHs were selected which were characterized by stable contents of α-T, β-T, γ-T, δ-T and total-T with the simultaneous stable content of PC-8. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Near-infrared reflectance spectroscopy predicts protein, starch, and seed weight in intact seeds of common bean ( Phaseolus vulgaris L.).

PubMed

Hacisalihoglu, Gokhan; Larbi, Bismark; Settles, A Mark

2010-01-27

The objective of this study was to explore the potential of near-infrared reflectance (NIR) spectroscopy to determine individual seed composition in common bean ( Phaseolus vulgaris L.). NIR spectra and analytical measurements of seed weight, protein, and starch were collected from 267 individual bean seeds representing 91 diverse genotypes. Partial least-squares (PLS) regression models were developed with 61 bean accessions randomly assigned to a calibration data set and 30 accessions assigned to an external validation set. Protein gave the most accurate PLS regression, with the external validation set having a standard error of prediction (SEP) = 1.6%. PLS regressions for seed weight and starch had sufficient accuracy for seed sorting applications, with SEP = 41.2 mg and 4.9%, respectively. Seed color had a clear effect on the NIR spectra, with black beans having a distinct spectral type. Seed coat color did not impact the accuracy of PLS predictions. This research demonstrates that NIR is a promising technique for simultaneous sorting of multiple seed traits in single bean seeds with no sample preparation.

Fast radioactive seed localization in intraoperative cone beam CT for low-dose-rate prostate brachytherapy

NASA Astrophysics Data System (ADS)

Hu, Yu-chi; Xiong, Jian-ping; Cohan, Gilad; Zaider, Marco; Mageras, Gig; Zelefsky, Michael

2013-03-01

A fast knowledge-based radioactive seed localization method for brachytherapy was developed to automatically localize radioactive seeds in an intraoperative volumetric cone beam CT (CBCT) so that corrections, if needed, can be made during prostate implant surgery. A transrectal ultrasound (TRUS) scan is acquired for intraoperative treatment planning. Planned seed positions are transferred to intraoperative CBCT following TRUS-to-CBCT registration using a reference CBCT scan of the TRUS probe as a template, in which the probe and its external fiducial markers are pre-segmented and their positions in TRUS are known. The transferred planned seeds and probe serve as an atlas to reduce the search space in CBCT. Candidate seed voxels are identified based on image intensity. Regions are grown from candidate voxels and overlay regions are merged. Region volume and intensity variance is checked against known seed volume and intensity profile. Regions meeting the above criteria are flagged as detected seeds; otherwise they are flagged as likely seeds and sorted by a score that is based on volume, intensity profile and distance to the closest planned seed. A graphical interface allows users to review and accept or reject likely seeds. Likely seeds with approximately twice the seed volume are automatically split. Five clinical cases are tested. Without any manual correction in seed detection, the method performed the localization in 5 seconds (excluding registration time) for a CBCT scan with 512×512×192 voxels. The average precision rate per case is 99% and the recall rate is 96% for a total of 416 seeds. All false negative seeds are found with 15 in likely seeds and 1 included in a detected seed. With the new method, updating of calculations of dose distribution during the procedure is possible and thus facilitating evaluation and improvement of treatment quality.

Probing loop quantum gravity with evaporating black holes.

PubMed

Barrau, A; Cailleteau, T; Cao, X; Diaz-Polo, J; Grain, J

2011-12-16

This Letter aims at showing that the observation of evaporating black holes should allow the usual Hawking behavior to be distinguished from loop quantum gravity (LQG) expectations. We present a full Monte Carlo simulation of the evaporation in LQG and statistical tests that discriminate between competing models. We conclude that contrarily to what was commonly thought, the discreteness of the area in LQG leads to characteristic features that qualify evaporating black holes as objects that could reveal quantum gravity footprints. © 2011 American Physical Society

Diversity and relatedness in a black walnut seed orchard

Treesearch

Keith Woeste; Doug Mersman

2003-01-01

Geneticists and silviculturists have selected over 450 black walnut clones for inclusion in the black walnut breeding program at Purdue University over the past 35 years. Most of the selections were from Indiana; a few were from other states in the Central Hardwoods Region. Selection of second and third generation clones out of this founder population was based...

Formative Assessment Probes: Big and Small Seeds. Linking Formative Assessment Probes to the Scientific Practices

ERIC Educational Resources Information Center

Keeley, Page

2016-01-01

This column focuses on promoting learning through assessment. Formative assessment probes are designed to uncover students' ideas about objects, events, and processes in the natural world. This assessment information is then used throughout instruction to move students toward an understanding of the scientific ideas behind the probes. During the…

Oxygen mapping: Probing a novel seeding strategy for bone tissue engineering.

PubMed

Westphal, Ines; Jedelhauser, Claudia; Liebsch, Gregor; Wilhelmi, Arnd; Aszodi, Attila; Schieker, Matthias

2017-04-01

Bone tissue engineering (BTE) utilizing biomaterial scaffolds and human mesenchymal stem cells (hMSCs) is a promising approach for the treatment of bone defects. The quality of engineered tissue is crucially affected by numerous parameters including cell density and the oxygen supply. In this study, a novel oxygen-imaging sensor was introduced to monitor the oxygen distribution in three dimensional (3D) scaffolds in order to analyze a new cell-seeding strategy. Immortalized hMSCs, pre-cultured in a monolayer for 30-40% or 70-80% confluence, were used to seed demineralized bone matrix (DBM) scaffolds. Real-time measurements of oxygen consumption in vitro were simultaneously performed by the novel planar sensor and a conventional needle-type sensor over 24 h. Recorded oxygen maps of the novel planar sensor revealed that scaffolds, seeded with hMSCs harvested at lower densities (30-40% confluence), exhibited rapid exponential oxygen consumption profile. In contrast, harvesting cells at higher densities (70-80% confluence) resulted in a very slow, almost linear, oxygen decrease due to gradual achieving the stationary growth phase. In conclusion, it could be shown that not only the seeding density on a scaffold, but also the cell density at the time point of harvest is of major importance for BTE. The new cell seeding strategy of harvested MSCs at low density during its log phase could be a useful strategy for an early in vivo implantation of cell-seeded scaffolds after a shorter in vitro culture period. Furthermore, the novel oxygen imaging sensor enables a continuous, two-dimensional, quick and convenient to handle oxygen mapping for the development and optimization of tissue engineered scaffolds. Biotechnol. Bioeng. 2017;114: 894-902. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Van Allen Probe Observations of Chorus Wave Activity, Source and Seed electrons, and the Radiation Belt Response During ICME and CIR Storms

NASA Astrophysics Data System (ADS)

Bingham, S.; Mouikis, C.; Kistler, L. M.; Farrugia, C. J.; Paulson, K. W.; Huang, C. L.; Boyd, A. J.; Spence, H. E.; Kletzing, C.

2017-12-01

Whistler mode chorus waves are electromagnetic waves that have been shown to be a major contributor to enhancements in the outer radiation belt during geomagnetic storms. The temperature anisotropy of source electrons (10s of keV) provides the free energy for chorus waves, which can accelerate sub-relativistic seed electrons (100s of keV) to relativistic energies. This study uses Van Allen Probe observations to examine the excitation and plasma conditions associated with chorus wave observations, the development of the seed population, and the outer radiation belt response in the inner magnetosphere, for 25 ICME and 35 CIR storms. Plasma data from the Helium Oxygen Proton Electron (HOPE) instrument and magnetic field measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) are used to identify chorus wave activity and to model a linear theory based proxy for chorus wave growth. A superposed epoch analysis shows a peak of chorus wave power on the dawnside during the storm main phase that spreads towards noon during the storm recovery phase. According to the linear theory results, this wave activity is driven by the enhanced convection driving plasma sheet electrons across the dayside. Both ICME and CIR storms show comparable levels of wave growth. Plasma data from the Magnetic Electron Ion Spectrometer (MagEIS) and the Relativistic Electron Proton Telescope (REPT) are used to observe the seed and relativistic electrons. A superposed epoch analysis of seed and relativistic electrons vs. L shows radiation belt enhancements with much greater frequency in the ICME storms, coinciding with a much stronger and earlier seed electron enhancement in the ICME storms.

Identification and Validation of Loci Governing Seed Coat Color by Combining Association Mapping and Bulk Segregation Analysis in Soybean

PubMed Central

Ma, Yansong; Tian, Long; Li, Xinxiu; Li, Ying-Hui; Guan, Rongxia; Guo, Yong; Qiu, Li-Juan

2016-01-01

Soybean seed coat exists in a range of colors from yellow, green, brown, black, to bicolor. Classical genetic analysis suggested that soybean seed color was a moderately complex trait controlled by multi-loci. However, only a couple of loci could be detected using a single biparental segregating population. In this study, a combination of association mapping and bulk segregation analysis was employed to identify genes/loci governing this trait in soybean. A total of 14 loci, including nine novel and five previously reported ones, were identified using 176,065 coding SNPs selected from entire SNP dataset among 56 soybean accessions. Four of these loci were confirmed and further mapped using a biparental population developed from the cross between ZP95-5383 (yellow seed color) and NY279 (brown seed color), in which different seed coat colors were further dissected into simple trait pairs (green/yellow, green/black, green/brown, yellow/black, yellow/brown, and black/brown) by continuously developing residual heterozygous lines. By genotyping entire F2 population using flanking markers located in fine-mapping regions, the genetic basis of seed coat color was fully dissected and these four loci could explain all variations of seed colors in this population. These findings will be useful for map-based cloning of genes as well as marker-assisted breeding in soybean. This work also provides an alternative strategy for systematically isolating genes controlling relative complex trait by association analysis followed by biparental mapping. PMID:27404272

The growth efficiency of high-redshift black holes

NASA Astrophysics Data System (ADS)

Pacucci, Fabio; Volonteri, Marta; Ferrara, Andrea

2015-09-01

The observational evidence that Super-Massive Black Holes (M• ˜ 109-10 M⊙) are already in place less than 1 Gyr after the big bang poses stringent time constraints on the growth efficiency of their seeds. Among proposed possibilities, the formation of massive (˜103-6 M⊙) seeds and/or the occurrence of super-Eddington (dot{M}>dot{M}_{Edd}) accretion episodes may contribute to the solution of this problem. In this work, using a set of astrophysically motivated initial conditions, we analytically and numerically investigate the accretion flow on to high-redshift (z ˜ 10) black holes to understand the physical requirements favouring rapid and efficient growth. Our model identifies a `feeding-dominated' accretion regime and a `feedback-limited' one, the latter being characterized by intermittent (duty cycles D ≲ 0.5) and inefficient growth, with recurring outflow episodes. We find that low-mass seeds (≲103-4 M⊙) evolve in the feedback-limited regime, while more massive seeds (≳105-6 M⊙) grow very rapidly as they are found in the feeding-dominated regime. In addition to the standard accretion model with a fixed matter-energy conversion factor (ɛ = 0.1), we have also explored slim disc models, appropriate for super-Eddington accretion, where radiation is trapped in the disc and the radiative efficiency is reduced (ɛ ≲ 0.04), which may ensure a continuous growth with dot{M} ≫ dot{M}_{Edd} (up to {˜ } 300 dot{M}_{Edd} in our simulations). Under these conditions, outflows play a negligible role and a black hole can accrete 80-100 per cent of the gas mass of the host halo (˜107 M⊙) in ˜10 Myr, while in feedback-limited systems we predict that black holes can accrete only up to ˜15 per cent of the available mass.

Assessment of Black Ash (Fraxinus nigra) Decline in Minnesota. Chapter 12

Treesearch

Brian J. Palik; Michael E. Ostry; Robert C. Venette; Kathleen T. Ward

2012-01-01

Black ash (Fraxinus nigra) is present throughout the upper Midwest and Northeastern United States and is often found in lowland hardwood forests. Black ash seed is an important food for birds and small mammals, and its twigs and foliage are used by ungulates. Black ash wood is valued for paneling and furniture as well as for Native American basketry...

A universal minimal mass scale for present-day central black holes

NASA Astrophysics Data System (ADS)

Alexander, Tal; Bar-Or, Ben

2017-08-01

The early stages of massive black hole growth are poorly understood1. High-luminosity active galactic nuclei at very high redshift2 z further imply rapid growth soon after the Big Bang. Suggested formation mechanisms typically rely on the extreme conditions found in the early Universe (very low metallicity, very high gas or star density). It is therefore plausible that these black hole seeds were formed in dense environments, at least a Hubble time ago (z > 1.8 for a look-back time of tH = 10 Gyr)3. Intermediate-mass black holes (IMBHs) of mass M• ≈ 102-105 solar masses, M⊙, are the long-sought missing link4 between stellar black holes, born of supernovae5, and massive black holes6, tied to galaxy evolution by empirical scaling relations7,8. The relation between black hole mass, M•, and stellar velocity dispersion, σ★, that is observed in the local Universe over more than about three decades in massive black hole mass, correlates M• and σ★ on scales that are well outside the massive black hole's radius of dynamical influence6, rh≈GM•/σ★2. We show that low-mass black hole seeds that accrete stars from locally dense environments in galaxies following a universal M•/σ★ relation9,10 grow over the age of the Universe to be above M0≈3×105M⊙ (5% lower limit), independent of the unknown seed masses and formation processes. The mass M0 depends weakly on the uncertain formation redshift, and sets a universal minimal mass scale for present-day black holes. This can explain why no IMBHs have yet been found6, and it implies that present-day galaxies with σ★ < S0 ≈ 40 km s-1 lack a central black hole, or formed it only recently. A dearth of IMBHs at low redshifts has observable implications for tidal disruptions11 and gravitational wave mergers12.

Seed colour affects light and temperature requirements during germination in two Lotus species (Fabaceae) of the Arabian subtropical deserts.

PubMed

Bhatt, Arvind; Gairola, Sanjay; El-Keblawy, Ali A

2016-06-01

Heterogeneity in seeds mostly occurs due to physiological, environmental and genetic factors, and these could affect seed dormancy and germination. Therefore, the aim of our study was to assess the effect of seed colour on germination behavior. For this, both light and temperature requirements were assessed in Lotus glinoides and Lotus halophilus (Fabaceae) from the hyper-arid deserts of the United Arab Emirates. Germination was assessed in terms of both final germination level (percentage) and germination rate, as expressed by Timson’s germination velocity index. Lotus glinoides produces black and yellow-colored seeds, and L. halophilus produces green and yellow seeds. Different seed lots were germinated in both light and darkness at different temperatures. Yellow seeds of the two species attained significantly lower germination, compared to black and green seeds. There was no specific light or temperature requirements for the germination of the two coloured seeds of L. glinoides; the effect of interactions between seed colour and both light and incubation temperature, were not significant on the final germination percentage. In L. halophilus, green seeds germinated significantly more in both light and darkness at lower temperatures (15/25 °C) and in light at higher temperatures (25/35 °C), compared to yellow seeds. Yellow seeds germinated faster, compared to black at 15/25 °C in L. glinoides and compared to green seeds at 15/25 °C and 25/35 °C in L. halophilus. Seed colour variation, at least in L. halophilus, could be a survival strategy that would determine the time of germination throughout the year in the unpredictable desert environment.

Is There a Role for Oligosaccharides in Seed Longevity? An Assessment of Intracellular Glass Stability1

PubMed Central

Buitink, Julia; Hemminga, Marcus A.; Hoekstra, Folkert A.

2000-01-01

We examined whether oligosaccharides extend seed longevity by increasing the intracellular glass stability. For that purpose, we used a spin probe technique to measure the molecular mobility and glass transition temperature of the cytoplasm of impatiens (Impatiens walleriana) and bell pepper (Capsicum annuum) seeds that were osmo-primed to change oligosaccharide content and longevity. Using saturation transfer electron paramagnetic resonance spectroscopy, we found that the rotational correlation time of the polar spin probe 3-carboxy-proxyl in the cytoplasm decreased, together with longevity, as a function of increasing seed water content, suggesting that longevity may indeed be regulated by cytoplasmic mobility. Osmo-priming of the seeds resulted in considerable decreases in longevity and oligosaccharide content, while the sucrose content increased. No difference in the glass transition temperature was found between control and primed impatiens seeds at the same temperature and water content. Similarly, there was no difference in the rotational motion of the spin probe in the cytoplasm between control and primed impatiens and bell pepper seeds. We therefore conclude that oligosaccharides in seeds do not affect the stability of the intracellular glassy state, and that the reduced longevity after priming is not the result of increased molecular mobility in the cytoplasm. PMID:10759518

Direct probe of the inner accretion flow around the supermassive black hole in NGC 2617

NASA Astrophysics Data System (ADS)

Giustini, M.; Costantini, E.; De Marco, B.; Svoboda, J.; Motta, S. E.; Proga, D.; Saxton, R.; Ferrigno, C.; Longinotti, A. L.; Miniutti, G.; Grupe, D.; Mathur, S.; Shappee, B. J.; Prieto, J. L.; Stanek, K.

2017-01-01

Aims: NGC 2617 is a nearby (z 0.01) active galaxy that recently switched from being a Seyfert 1.8 to be a Seyfert 1.0. At the same time, it underwent a strong increase of X-ray flux by one order of magnitude with respect to archival measurements. We characterise the X-ray spectral and timing properties of NGC 2617 with the aim of studying the physics of a changing-look active galactic nucleus (AGN). Methods: We performed a comprehensive timing and spectral analysis of two XMM-Newton pointed observations spaced by one month, complemented by archival quasi-simultaneous INTEGRAL observations. Results: We found that, to the first order, NGC 2617 looks like a type 1 AGN in the X-ray band and, with the addition of a modest reflection component, its continuum can be modelled well either with a power law plus a phenomenological blackbody, a partially covered power law, or a double Comptonisation model. Independent of the continuum adopted, in all three cases a column density of a few 1023 cm-2 of neutral gas covering 20-40% of the continuum source is required by the data. Most interestingly, absorption structures due to highly ionised iron have been detected in both observations with a redshift of about 0.1c with respect to the systemic redshift of the host galaxy. Conclusions: The redshifted absorber can be ascribed to a failed wind/aborted jets component, to gravitational redshift effects, and/or to matter directly falling towards the central supermassive black hole. In either case, we are probing the innermost accretion flow around the central supermassive black hole of NGC 2617 and might be even watching matter in a direct inflow towards the black hole itself.

The mass function of black holes 1

NASA Astrophysics Data System (ADS)

Natarajan, Priyamvada; Volonteri, Marta

2012-05-01

In this paper, we compare the observationally derived black hole mass function (BHMF) of luminous (>1045-1046 erg s-1) broad-line quasars (BLQSOs) at 1 < z < 4.5 drawn from the Sloan Digital Sky Survey (SDSS) presented by Kelly et al., with models of merger-driven black hole (BH) growth in the context of standard hierarchical structure formation models. In these models, we explore two distinct black hole seeding prescriptions at the highest redshifts: 'light seeds'- remnants of Population III stars and 'massive seeds' that form from the direct collapse of pre-galactic discs. The subsequent merger triggered mass build-up of the black hole population is tracked over cosmic time under the assumption of a fixed accretion rate as well as rates drawn from the distribution derived by Merloni & Heinz. Four model snapshots at z= 1.25, 2, 3.25 and 4.25 are compared with the SDSS-derived BHMFs of BLQSOs. We find that the light seed models fall short of reproducing the observationally derived mass function of BLQSOs at MBH > 109 M⊙ throughout the redshift range; the massive seed models with a fixed accretion rate of 0.3 Edd, or with accretion rates drawn from the Merloni & Heinz distribution provide the best fit to the current observational data at z > 2, although they overestimate the high-mass end of the mass function at lower redshifts. At low redshifts, a drastic drop in the accretion rate is observed and this is explained as arising due to the diminished gas supply available due to consumption by star formation or changes in the geometry of the inner feeding regions. Therefore, the overestimate at the high-mass end of the black hole mass function for the massive seed models can be easily modified, as the accretion rate is likely significantly lower at these epochs than what we assume. For the Merloni & Heinz model, examining the Eddington ratio distributions fEdd, we find that they are almost uniformly sampled from fEdd= 10-2 to 1 at z≃ 1, while at high redshift

Anticancer activity of Nigella sativa (black seed) and its relationship with the thermal processing and quinone composition of the seed.

PubMed

Agbaria, Riad; Gabarin, Adi; Dahan, Arik; Ben-Shabat, Shimon

2015-01-01

The traditional preparation process of Nigella sativa (NS) oil starts with roasting of the seeds, an allegedly unnecessary step that was never skipped. The aims of this study were to investigate the role and boundaries of thermal processing of NS seeds in the preparation of therapeutic extracts and to elucidate the underlying mechanism. NS extracts obtained by various seed thermal processing methods were investigated in vitro for their antiproliferative activity in mouse colon carcinoma (MC38) cells and for their thymoquinone content. The effect of the different methods of thermal processing on the ability of the obtained NS oil to inhibit the nuclear factor kappa B (NF-κB) pathway was then investigated in Hodgkin's lymphoma (L428) cells. The different thermal processing protocols yielded three distinct patterns: heating the NS seeds to 50°C, 100°C, or 150°C produced oil with a strong ability to inhibit tumor cell growth; no heating or heating to 25°C had a mild antiproliferative effect; and heating to 200°C or 250°C had no effect. Similar patterns were obtained for the thymoquinone content of the corresponding oils, which showed an excellent correlation with the antiproliferative data. It is proposed that there is an oxidative transition mechanism between quinones after controlled thermal processing of the seeds. While NS oil from heated seeds delayed the expression of NF-κB transcription, non-heated seeds resulted in only 50% inhibition. The data indicate that controlled thermal processing of NS seeds (at 50°C-150°C) produces significantly higher anticancer activity associated with a higher thymoquinone oil content, and inhibits the NF-κB signaling pathway.

In vitro sterilization technique on embryo of black Toraja rice

NASA Astrophysics Data System (ADS)

Haring, F.; Riadi, M.; Rafiuddin; Sjahril, R.; Muchlis, A. R.

2018-05-01

Toraja black rice has a high anthocyanin content, a water-soluble pigments, with antioxidant activity. Toraja black rice has a variety of seeds colour in one panicles such as full black (the outside and inside the rice), medium black (the outside and slightly inside rice) and a little black (only the outside of rice). Embryo culture in vitro is one way to grow plants in sterile conditions. The presence of contamination and the death of the embryo require in vitro embryo culture. The sterilization technique is a very important first step to eliminate contamination and the death of embryos. This research aims to determine the right material composition for sterilization of black rice’s embryo. The experiment was done by growing black rice on half strength MS media with the treatment of three method of sterilization, i.e.: S1 (70% alcohol for 5 minutes, 3% and 2% Chlorox each for 10 minutes,), S2 (70% alcohol for 3 minutes, 2% Clorox for 10 minutes) and S3 (70% alcohol for 3 minutes and 1% Clorox for 15 minutes). The materials used are rice seedlings that have been cut in two and opened the pericarp of paddy grain, leaving a piece of rice that has a complete embryo. The best sterilization for Toraja black rice embryo culture was using the S3 composition. Best germination was seen on the seeds with full and medium black color.

Image-processing algorithms for inspecting characteristics of hybrid rice seed

NASA Astrophysics Data System (ADS)

Cheng, Fang; Ying, Yibin

2004-03-01

Incompletely closed glumes, germ and disease are three characteristics of hybrid rice seed. Image-processing algorithms developed to detect these seed characteristics were presented in this paper. The rice seed used for this study involved five varieties of Jinyou402, Shanyou10, Zhongyou207, Jiayou and IIyou. The algorithms were implemented with a 5*600 images set, a 4*400 images set and the other 5*600 images set respectively. The image sets included black background images, white background images and both sides images of rice seed. Results show that the algorithm for inspecting seeds with incompletely closed glumes based on Radon Transform achieved an accuracy of 96% for normal seeds, 92% for seeds with fine fissure and 87% for seeds with unclosed glumes, the algorithm for inspecting germinated seeds on panicle based on PCA and ANN achieved n average accuracy of 98% for normal seeds, 88% for germinated seeds on panicle and the algorithm for inspecting diseased seeds based on color features achieved an accuracy of 92% for normal and healthy seeds, 95% for spot diseased seeds and 83% for severe diseased seeds.

Phytochemical profile of a Japanese black-purple rice.

PubMed

Pereira-Caro, Gema; Watanabe, Shin; Crozier, Alan; Fujimura, Tatsuhito; Yokota, Takao; Ashihara, Hiroshi

2013-12-01

Black-purple rice is becoming popular with health conscious food consumers. In the present study, the secondary metabolites in dehulled black-purple rice cv. Asamurasaki were analysed using HPLC-PDA-MS(2). The seeds contained a high concentration of seven anthocyanins (1400 μg/g fresh weight) with cyanidin-3-O-glucoside and peonidin-3-O-glucoside predominating. Five flavonol glycosides, principally quercetin-3-O-glucoside and quercetin-3-O-rutinoside, and flavones were detected at a total concentration of 189 μg/g. The seeds also contained 3.9 μg/g of carotenoids consisting of lutein, zeaxanthin, lycopene and β-carotene. γ-Oryzanol (279 μg/g) was also present as a mixture of 24-methylenecycloartenol ferulate, campesterol ferulate, cycloartenol ferulate and β-sitosterol ferulate. No procyanidins were detected in this variety of black-purple rice. The results demonstrate that the black-purple rice in the dehulled form in which it is consumed by humans contains a rich heterogeneous mixture of phytochemicals which may provide a basis for the potential health benefits, and highlights the possible use of the rice as functional food. Copyright © 2013 Elsevier Ltd. All rights reserved.

Immunoaffinity column cleanup with liquid chromatography using postcolumn bromination for the determination of aflatoxins in black and white sesame seed: single-laboratory validation.

PubMed

Liu, Guihua; Zhu, Zhou; Cheng, Jinquan; Senyuva, Hamide Z

2012-01-01

A single-laboratory validation was conducted to establish the effectiveness of an immunoaffinity column cleanup procedure followed by LC with fluorescence detection for the determination of aflatoxins B1, B2, G1, and G2 in sesame seeds. The sample is homogenized with 50% water (w/w) to form a slurry, then the test portion is extracted with methanol-water (60 + 40, v/v) using a high-speed blender. The sample extract is filtered, diluted with 15% Tween 20 in phosphate-buffered saline solution, and applied to an immunoaffinity column. Aflatoxins are removed with neat methanol, then directly determined by RP-LC with fluorescence detection using postcolumn bromination (Kobra cell). Test portions of blank white sesame seed slurry were spiked with a mixture of aflatoxins to give total levels of 4 and 10 microg/kg. Recoveries for individual and total aflatoxins ranged from 92.7 to 110.3% for spiked samples. Based on results for spiked sesame paste (triplicates at two levels), the RSD for repeatability (RSD(r)) averaged 1.1% for total aflatoxins and 1.4% for aflatoxin B1. The method was demonstrated to be applicable to naturally contaminated samples of black and white sesame seeds obtained from local markets in China.

The characteristic black hole mass resulting from direct collapse in the early Universe

NASA Astrophysics Data System (ADS)

Latif, M. A.; Schleicher, D. R. G.; Schmidt, W.; Niemeyer, J. C.

2013-12-01

Black holes of a billion solar masses are observed in the infant Universe a few hundred million years after the big bang. The direct collapse of protogalactic gas clouds in primordial haloes with Tvir ≥ 104 K provides the most promising way to assemble massive black holes. In this study, we aim to determine the characteristic mass scale of seed black holes and the time evolution of the accretion rates resulting from the direct collapse model. We explore the formation of supermassive black holes via cosmological large eddy simulations (LES) by employing sink particles and following their evolution for 20 000 yr after the formation of the first sink. As the resulting protostars were shown to have cool atmospheres in the presence of strong accretion, we assume here that UV feedback is negligible during this calculation. We confirm this result in a comparison run without sinks. Our findings show that black hole seeds with characteristic mass of 105 M⊙ are formed in the presence of strong Lyman-Werner flux which leads to an isothermal collapse. The characteristic mass is about two times higher in LES compared to the implicit large eddy simulations. The accretion rates increase with time and reach a maximum value of 10 M⊙ yr-1 after 104 yr. Our results show that the direct collapse model is clearly feasible as it provides the expected mass of the seed black holes.

Black hole thermalization, D0 brane dynamics, and emergent spacetime

NASA Astrophysics Data System (ADS)

Riggins, Paul; Sahakian, Vatche

2012-08-01

When matter falls past the horizon of a large black hole, the expectation from string theory is that the configuration thermalizes and the information in the probe is rather quickly scrambled away. The traditional view of a classical unique spacetime near a black hole horizon conflicts with this picture. The question then arises as to what spacetime does the probe actually see as it crosses a horizon, and how does the background geometry imprint its signature onto the thermal properties of the probe. In this work, we explore these questions through an extensive series of numerical simulations of D0 branes. We determine that the D0 branes quickly settle into an incompressible symmetric state—thermalized within a few oscillations through a process driven entirely by internal nonlinear dynamics. Surprisingly, thermal background fluctuations play no role in this mechanism. Signatures of the background fields in this thermal state arise either through fluxes, i.e. black hole hair; or if the probe expands to the size of the horizon—which we see evidence of. We determine simple scaling relations for the D0 branes’ equilibrium size, time to thermalize, lifetime, and temperature in terms of their number, initial energy, and the background fields. Our results are consistent with the conjecture that black holes are the fastest scramblers as seen by matrix theory.

Statistical properties of the radiation belt seed population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, A. J.; Spence, H. E.; Huang, C. -L.

Here, we present a statistical analysis of phase space density data from the first 26 months of the Van Allen Probes mission. In particular, we investigate the relationship between the tens and hundreds of keV seed electrons and >1 MeV core radiation belt electron population. Using a cross-correlation analysis, we find that the seed and core populations are well correlated with a coefficient of ≈0.73 with a time lag of 10–15 h. We present evidence of a seed population threshold that is necessary for subsequent acceleration. The depth of penetration of the seed population determines the inner boundary of themore » acceleration process. However, we show that an enhanced seed population alone is not enough to produce acceleration in the higher energies, implying that the seed population of hundreds of keV electrons is only one of several conditions required for MeV electron radiation belt acceleration.« less

Statistical properties of the radiation belt seed population

DOE PAGES

Boyd, A. J.; Spence, H. E.; Huang, C. -L.; ...

2016-07-25

Here, we present a statistical analysis of phase space density data from the first 26 months of the Van Allen Probes mission. In particular, we investigate the relationship between the tens and hundreds of keV seed electrons and >1 MeV core radiation belt electron population. Using a cross-correlation analysis, we find that the seed and core populations are well correlated with a coefficient of ≈0.73 with a time lag of 10–15 h. We present evidence of a seed population threshold that is necessary for subsequent acceleration. The depth of penetration of the seed population determines the inner boundary of themore » acceleration process. However, we show that an enhanced seed population alone is not enough to produce acceleration in the higher energies, implying that the seed population of hundreds of keV electrons is only one of several conditions required for MeV electron radiation belt acceleration.« less

Limits on runaway growth of intermediate mass black holes from advanced LIGO

NASA Astrophysics Data System (ADS)

Kovetz, Ely D.; Cholis, Ilias; Kamionkowski, Marc; Silk, Joseph

2018-06-01

There is growing evidence that intermediate-mass black holes (IMBHs), defined here as having a mass in the range M =500 -105 M⊙ , are present in the dense centers of certain globular clusters (GCs). Gravitational waves from their mergers with other IMBHs or with stellar BHs in the cluster are mostly emitted in frequencies ≲10 Hz , which unfortunately is out of reach for current ground-based observatories such as advanced LIGO (aLIGO). Nevertheless, we show that aLIGO measurements can be used to efficiently probe one of the possible formation mechanisms of IMBHs in GCs, namely a runaway merger process of stellar seed BHs. In this case, aLIGO will be sensitive to the lower-mass rungs of the merger ladder, ranging from the seed BH mass to masses ≳50 - 300 M⊙ , where the background from standard mergers is expected to be very low. Assuming this generic IMBH formation scenario, we calculate the mass functions that correspond to the limiting cases of possible merger trees. Based on estimates for the number density of GCs and taking into account the instrumental sensitivity, we show that current observations do not effectively limit the occupation fraction focc of IMBHs formed by runaway mergers of stellar BHs in GCs. However, we find that if runaway mergers occur steadily throughout the lifetimes of GCs (as opposed to happening mainly early in their lifetimes), then a six-year run of aLIGO at design sensitivity will be able to probe down to focc≲3 % at a 99.9% confidence level, either finding evidence for this formation mechanism, or necessitating others if the fraction of GCs that harbor IMBHs is higher.

Black rhinoceros (Diceros bicornis) and domestic horse (Equus caballus) hindgut microflora demonstrate similar fermentation responses to grape seed extract supplementation in vitro.

PubMed

Huntley, N F; Naumann, H D; Kenny, A L; Kerley, M S

2017-10-01

The domestic horse is used as a nutritional model for rhinoceros maintained under human care. The validity of this model for browsing rhinoceros has been questioned due to high prevalence of iron overload disorder (IOD) in captive black rhinoceros (Diceros bicornis), which is associated with high morbidity and mortality. Iron chelators, such as tannins, are under investigation as dietary supplements to ameliorate or prevent IOD in prone species. Polyphenolic compounds variably affect microbial fermentation, so the first objective of this experiment was to evaluate the effects of grape seed extract (GSE; a concentrated source of condensed tannins; CT) on black rhinoceros hindgut fermentation. Equine nutrition knowledge is used to assess supplements for rhinoceros; therefore, the second objective was to evaluate the domestic horse model for black rhinoceros fermentation and compare fermentation responses to GSE using a continuous single-flow in vitro culture system. Two replicated continuous culture experiments were conducted using horse and black rhinoceros faeces as inoculum sources comparing four diets with increasing GSE inclusion (0.0%, 1.3%, 2.7% and 4.0% of diet dry matter). Diet and GSE polyphenolic compositions were determined, and sodium sulphite effect on neutral detergent fibre extraction of CT-containing forages was tested. Increasing GSE inclusion stimulated microbial growth and fermentation, and proportionally increased diet CT concentration and iron-binding capacity. Horse and black rhinoceros hindgut microflora nutrient digestibility and fermentation responses to GSE did not differ, and results supported equine fermentation as an adequate model for microbial fermentation in the black rhinoceros. Interpretation of these results is limited to hindgut fermentation and further research is needed to compare foregut digestibility and nutrient absorption between these two species. Supplementation of GSE in black rhinoceros diets up to 4% is unlikely to

Merging Black Holes

NASA Technical Reports Server (NTRS)

Centrella, Joan; Baker, John G.; Kelly, Bernard J.; vanMeter, James R.

2010-01-01

Black-hole mergers take place in regions of very strong and dynamical gravitational fields, and are among the strongest sources of gravitational radiation. Probing these mergers requires solving the full set of Einstein's equations of general relativity numerically. For more than 40 years, progress towards this goal has been very slow, as numerical relativists encountered a host of difficult problems. Recently, several breakthroughs have led to dramatic progress, enabling stable and accurate calculations of black-hole mergers. This article presents an overview of this field, including impacts on astrophysics and applications in gravitational wave data analysis.

Various extraction and analytical techniques for isolation and identification of secondary metabolites from Nigella sativa seeds.

PubMed

Liu, X; Abd El-Aty, A M; Shim, J-H

2011-10-01

Nigella sativa L. (black cumin), commonly known as black seed, is a member of the Ranunculaceae family. This seed is used as a natural remedy in many Middle Eastern and Far Eastern countries. Extracts prepared from N. sativa have, for centuries, been used for medical purposes. Thus far, the organic compounds in N. sativa, including alkaloids, steroids, carbohydrates, flavonoids, fatty acids, etc. have been fairly well characterized. Herein, we summarize some new extraction techniques, including microwave assisted extraction (MAE) and supercritical extraction techniques (SFE), in addition to the classical method of hydrodistillation (HD), which have been employed for isolation and various analytical techniques used for the identification of secondary metabolites in black seed. We believe that some compounds contained in N. sativa remain to be identified, and that high-throughput screening could help to identify new compounds. A study addressing environmentally-friendly techniques that have minimal or no environmental effects is currently underway in our laboratory.

Volatile fingerprint of Brazilian defective coffee seeds: corroboration of potential marker compounds and identification of new low quality indicators.

PubMed

Toci, Aline T; Farah, Adriana

2014-06-15

In the present work, the volatile profiles of green and roasted Brazilian defective coffee seeds and their controls were characterised, totalling 159 compounds. Overall, defective seeds showed higher number and concentration of volatile compounds compared to those of control seeds, especially pyrazines, pyrroles and phenols. Corroborating our previous results, butyrolactone and hexanoic acid, previously considered as potential defective seeds' markers, were observed only in raw and roasted defective seeds, respectively, and not in control seeds. New compounds were suggested as potential defective seeds' markers: hexanoic acid (for raw and roasted defective seeds in general), butyrolactone (for raw defective seeds in general), and 3-ethyl-2-methyl-1,3-hexadiene (for raw black seeds); β-linalool and 2-butyl-3,5-dimethylpyrazine (for roasted defective seeds in general), and 2-pentylfuran (for roasted black seeds). Additional compounds suggested as low quality indicators were 2,3,5,6-tetramethylpyrazine,2,3-butanediol and 4-ethylguaiacol, β-linalool, 2-,3-dimethylbutyl butanoate, 2-phenylethyl acetate, 2,3-butanedione, hexanedioic acid, guaiacol, 2,3-dihydro-2-methyl-1H-benzopyrrol, 3-methylpiperidine, 2-pentylpiperidine, 3-octen-2-one, 2-octenal, 2-pentylfuran and 2-butyl-3-methylpyrazine. Copyright © 2014. Published by Elsevier Ltd.

Using a biased qubit to probe complex systems

NASA Astrophysics Data System (ADS)

Pollock, Felix A.; Checińska, Agata; Pascazio, Saverio; Modi, Kavan

2016-09-01

Complex mesoscopic systems play increasingly important roles in modern science, from understanding biological functions at the molecular level to designing solid-state information processing devices. The operation of these systems typically depends on their energetic structure, yet probing their energy landscape can be extremely challenging; they have many degrees of freedom, which may be hard to isolate and measure independently. Here, we show that a qubit (a two-level quantum system) with a biased energy splitting can directly probe the spectral properties of a complex system, without knowledge of how they couple. Our work is based on the completely positive and trace-preserving map formalism, which treats any unknown dynamics as a "black-box" process. This black box contains information about the system with which the probe interacts, which we access by measuring the survival probability of the initial state of the probe as function of the energy splitting and the process time. Fourier transforming the results yields the energy spectrum of the complex system. Without making assumptions about the strength or form of its coupling, our probe could determine aspects of a complex molecule's energy landscape as well as, in many cases, test for coherent superposition of its energy eigenstates.

Quantum probe of Hořava-Lifshitz gravity

NASA Astrophysics Data System (ADS)

Gurtug, O.; Mangut, M.

2018-04-01

Particle probe analysis of the Kehagias-Sfetsos black hole spacetime of Hořava-Lifshitz gravity is extended to wave probe analysis within the framework of quantum mechanics. The time-like naked singularity that develops when ωM2 < 1/2 is probed with quantum fields obeying Klein-Gordon and Chandrasekhar-Dirac equations. The quantum field probe of the naked singularity has revealed that both the spatial part of the wave and the Hamiltonian operators of Klein-Gordon and Chandrasekhar-Dirac equations are essentially self-adjoint, and thus, the naked singularity in the Kehagias-Sfetsos spacetime becomes quantum mechanically non-singular.

Photoacoustic imaging of prostate brachytherapy seeds with transurethral light delivery

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Guo, Xiaoyu; Song, Danny Y.; Boctor, Emad M.

2014-03-01

We present a novel approach to photoacoustic imaging of prostate brachytherapy seeds utilizing an existing urinary catheter for transurethral light delivery. Two canine prostates were surgically implanted with brachyther- apy seeds under transrectal ultrasound guidance. One prostate was excised shortly after euthanasia and fixed in gelatin. The second prostate was imaged in the native tissue environment shortly after euthanasia. A urinary catheter was inserted in the urethra of each prostate. A 1-mm core diameter optical fiber coupled to a 1064 nm Nd:YAG laser was inserted into the urinary catheter. Light from the fiber was either directed mostly parallel to the fiber axis (i.e. end-fire fire) or mostly 90° to the fiber axis (i.e. side-fire fiber). An Ultrasonix SonixTouch scanner, transrectal ultrasound probe with curvilinear (BPC8-4) and linear (BPL9-5) arrays, and DAQ unit were utilized for synchronized laser light emission and photoacoustic signal acquisition. The implanted brachytherapy seeds were visualized at radial distances of 6-16 mm from the catheter. Multiple brachytherapy seeds were si- multaneously visualized with each array of the transrectal probe using both delay-and-sum (DAS) and short-lag spatial coherence (SLSC) beamforming. This work is the first to demonstrate the feasibility of photoacoustic imaging of prostate brachytherapy seeds using a transurethral light delivery method.

The Early Growth of the First Black Holes

NASA Astrophysics Data System (ADS)

Johnson, Jarrett L.; Haardt, Francesco

2016-03-01

With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur at super-Eddington rates. Finally, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.

Black hole formation in the early Universe

NASA Astrophysics Data System (ADS)

Latif, M. A.; Schleicher, D. R. G.; Schmidt, W.; Niemeyer, J.

2013-08-01

Supermassive black holes with up to a 109 M⊙ dwell in the centres of present-day galaxies, and their presence has been confirmed at z ≥ 6. Their formation at such early epochs is still an enigma. Different pathways have been suggested to assemble supermassive black holes in the first billion years after the big bang. Direct collapse has emerged as a highly plausible scenario to form black holes as it provides seed masses of 105-106 M⊙. Gravitational collapse in atomic cooling haloes with virial temperatures Tvir ≥ 104 K may lead to the formation of massive seed black holes in the presence of an intense background ultraviolet flux. Turbulence plays a central role in regulating accretion and transporting angular momentum. We present here the highest resolution cosmological large eddy simulations to date which track the evolution of high-density regions on scales of 0.25 au beyond the formation of the first peak, and study the impact of subgrid-scale turbulence. The peak density reached in these simulations is 1.2 × 10-8 g cm-3. Our findings show that while fragmentation occasionally occurs, it does not prevent the growth of a central massive object resulting from turbulent accretion and occasional mergers. The central object reaches ˜1000 M⊙ within four free-fall times, and we expect further growth up to 106 M⊙ through accretion in about 1 Myr. The direct collapse model thus provides a viable pathway of forming high-mass black holes at early cosmic times.

Black soybean seed coat polyphenols prevent AAPH-induced oxidative DNA-damage in HepG2 cells

PubMed Central

Yoshioka, Yasukiyo; Li, Xiu; Zhang, Tianshun; Mitani, Takakazu; Yasuda, Michiko; Nanba, Fumio; Toda, Toshiya; Yamashita, Yoko; Ashida, Hitoshi

2017-01-01

Black soybean seed coat extract (BE), which contains abundant polyphenols such as procyanidins, cyanidin 3-glucoside, (+)-catechin, and (−)­epicatechin, has been reported on health beneficial functions such as antioxidant activity, anti-inflammatory, anti-obesity, and anti-diabetic activities. In this study, we investigated that prevention of BE and its polyphenols on 2,2'-azobis(2-methylpropionamide) dihydrochloride (AAPH)-induced oxidative DNA damage, and found that these polyphenols inhibited AAPH-induced formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker for oxidative DNA damage in HepG2 cells. Under the same conditions, these polyphenols also inhibited AAPH-induced accumulation of reactive oxygen species (ROS) in the cells. Inhibition of ROS accumulation was observed in both cytosol and nucleus. It was confirmed that these polyphenols inhibited formation of AAPH radical using oxygen radical absorbance capacity assay under the cell-free conditions. These results indicate that polyphenols in BE inhibit free radical-induced oxidative DNA damages by their potent antioxidant activity. Thus, BE is an effective food material for prevention of oxidative stress and oxidative DNA damages. PMID:28366989

Characterisation of fatty acid, carotenoid, tocopherol/tocotrienol compositions and antioxidant activities in seeds of three Chenopodium quinoa Willd. genotypes.

PubMed

Tang, Yao; Li, Xihong; Chen, Peter X; Zhang, Bing; Hernandez, Marta; Zhang, Hua; Marcone, Massimo F; Liu, Ronghua; Tsao, Rong

2015-05-01

Composition of fatty acids, tocopherols, tocotrienols, and carotenoids, and their contribution to antioxidant activities were investigated in seeds of three coloured quinoa cultivars (white, red and black). The major components and individual compounds were significantly different, and their concentrations were higher in darker seeds (p < 0.05). The oil yield was 6.58-7.17% which contained predominantly unsaturated fatty acids (89.42%). The ratio of omega-6/omega-3 fatty acid was ca. 6/1. The total tocopherol content ranged from 37.49 to 59.82 μg/g and mainly consisted of γ-tocopherol. Trace amount of α- and β-tocotrienols was also found. Black quinoa had the highest vitamin E followed by red and white quinoas. Carotenoids, mainly trans-lutein (84.7-85.6%) and zeaxanthin were confirmed for the first time in quinoa seeds, and the concentration was also the highest in black seeds. The antioxidant activities of lipophilic extracts were positively correlated with polyunsaturated fatty acids, total carotenoids and total tocopherols. Copyright © 2014. Published by Elsevier Ltd.

AZ-2000-IECW and StaMet Black Kapton Options for Solar Probe Plus MAG Sensor MLI Kevlar/Polyimide Shells

NASA Technical Reports Server (NTRS)

Choi, Michael K.

2017-01-01

AZ-2000-IECW white paint and StaMet black Kapton have been evaluated for the Kevlar/polyimide shells that enclose the Solar Probe Plus Magnetometer (MAG) sensors and multilayer insulation. Flight qualification testing on AZ-2000-IECW painted Kevlar/polyimide laminate was completed at Goddard Space Flight Center. This paint potentially meets all the requirements. However, it has no flight heritage. StaMet is hotter in the sun, and is specular. The results of the MAG thermal balance test show StaMet meets the thermal requirement and heater power budget. The mission prefers to fly StaMet after evaluating the risks of AZ-2000-IECW flaking and glint from StaMet to the Star Trackers.

California’s Hardwood Resource: Seeds, Seedlings, and Sprouts of Three Important Forest-Zone Species

Treesearch

Philip M. McDonald; John C. Tappeiner

2002-01-01

Although California black oak, tanoak, and Pacific madrone are the principal hardwood species in the forest zone of California and Oregon and are key components of many plant communities, their seed production, regeneration, and early growth requirements have received little study. Information is presented on seed production, storage, and germination, and on the...

Distribution of primary and specialized metabolites in Nigella sativa seeds, a spice with vast traditional and historical uses.

PubMed

Botnick, Ilan; Xue, Wentao; Bar, Einat; Ibdah, Mwafaq; Schwartz, Amnon; Joel, Daniel M; Lev, Efraim; Fait, Aaron; Lewinsohn, Efraim

2012-08-24

Black cumin (Nigella sativa L., Ranunculaceae) is an annual herb commonly used in the Middle East, India and nowadays gaining worldwide acceptance. Historical and traditional uses are extensively documented in ancient texts and historical documents. Black cumin seeds and oil are commonly used as a traditional tonic and remedy for many ailments as well as in confectionery and bakery. Little is known however about the mechanisms that allow the accumulation and localization of its active components in the seed. Chemical and anatomical evidence indicates the presence of active compounds in seed coats. Seed volatiles consist largely of olefinic and oxygenated monoterpenes, mainly p-cymene, thymohydroquinone, thymoquinone, γ-terpinene and α-thujene, with lower levels of sesquiterpenes, mainly longifolene. Monoterpene composition changes during seed maturation. γ-Terpinene and α-thujene are the major monoterpenes accumulated in immature seeds, and the former is gradually replaced by p-cymene, carvacrol, thymo-hydroquinone and thymoquinone upon seed development. These compounds, as well as the indazole alkaloids nigellidine and nigellicine, are almost exclusively accumulated in the seed coat. In contrast, organic and amino acids are primarily accumulated in the inner seed tissues. Sugars and sugar alcohols, as well as the amino alkaloid dopamine and the saponin α-hederin accumulate both in the seed coats and the inner seed tissues at different ratios. Chemical analyses shed light to the ample traditional and historical uses of this plant.

Phase transition of charged-AdS black holes and quasinormal modes: A time domain analysis

NASA Astrophysics Data System (ADS)

Chabab, M.; El Moumni, H.; Iraoui, S.; Masmar, K.

2017-10-01

In this work, we investigate the time evolution of a massless scalar perturbation around small and large RN-AdS4 black holes for the purpose of probing the thermodynamic phase transition. We show that below the critical point the scalar perturbation decays faster with increasing of the black hole size, both for small and large black hole phases. Our analysis of the time profile of quasinormal mode reveals a sharp distinction between the behaviors of both phases, providing a reliable tool to probe the black hole phase transition. However at the critical point P=Pc, as the black hole size extends, we note that the damping time increases and the perturbation decays faster, the oscillation frequencies raise either in small and large black hole phase. In this case the time evolution approach fails to track the AdS4 black hole phase.

Primordial black hole formation by vacuum bubbles

NASA Astrophysics Data System (ADS)

Deng, Heling; Vilenkin, Alexander

2017-12-01

Vacuum bubbles may nucleate during the inflationary epoch and expand, reaching relativistic speeds. After inflation ends, the bubbles are quickly slowed down, transferring their momentum to a shock wave that propagates outwards in the radiation background. The ultimate fate of the bubble depends on its size. Bubbles smaller than certain critical size collapse to ordinary black holes, while in the supercritical case the bubble interior inflates, forming a baby universe, which is connected to the exterior region by a wormhole. The wormhole then closes up, turning into two black holes at its two mouths. We use numerical simulations to find the masses of black holes formed in this scenario, both in subcritical and supercritical regime. The resulting mass spectrum is extremely broad, ranging over many orders of magnitude. For some parameter values, these black holes can serve as seeds for supermassive black holes and may account for LIGO observations.

Samara Probe For Remote Imaging

NASA Technical Reports Server (NTRS)

Burke, James D.

1989-01-01

Imaging probe descends through atmosphere of planet, obtaining images of ground surface as it travels. Released from aircraft over Earth or from spacecraft over another planet. Body and single wing shaped like samara - winged seed like those of maple trees. Rotates as descends, providing panoramic view of terrain below. Radio image obtained by video camera to aircraft or spacecraft overhead.

Black Hole Safari: Tracking Populations and Hunting Big Game

NASA Astrophysics Data System (ADS)

McConnell, N. J.

2013-10-01

Understanding the physical connection, or lack thereof, between the growth of galaxies and supermassive black holes is a key challenge in extragalactic astronomy. Dynamical studies of nearby galaxies are building a census of black hole masses across a broad range of galaxy types and uncovering statistical correlations between galaxy bulge properties and black hole masses. These local correlations provide a baseline for studying galaxies and black holes at higher redshifts. Recent measurements have probed the extremes of the supermassive black hole population and introduced surprises that challenge simple models of black hole and galaxy co-evolution. Future advances in the quality and quantity of dynamical black hole mass measurements will shed light upon the growth of massive galaxies and black holes in different cosmic environments.

Layer-Dependent Ultrafast Carrier and Coherent Phonon Dynamics in Black Phosphorus.

PubMed

Miao, Xianchong; Zhang, Guowei; Wang, Fanjie; Yan, Hugen; Ji, Minbiao

2018-05-09

Black phosphorus is a layered semiconducting material, demonstrating strong layer-dependent optical and electronic properties. Probing the photophysical properties on ultrafast time scales is of central importance in understanding many-body interactions and nonequilibrium quasiparticle dynamics. Here, we applied temporally, spectrally, and spatially resolved pump-probe microscopy to study the transient optical responses of mechanically exfoliated few-layer black phosphorus, with layer numbers ranging from 2 to 9. We have observed layer-dependent resonant transient absorption spectra with both photobleaching and red-shifted photoinduced absorption features, which could be attributed to band gap renormalization of higher subband transitions. Surprisingly, coherent phonon oscillations with unprecedented intensities were observed when the probe photons were in resonance with the optical transitions, which correspond to the low-frequency layer-breathing mode. Our results reveal strong Coulomb interactions and electron-phonon couplings in photoexcited black phosphorus, providing important insights into the ultrafast optical, nanomechanical, and optoelectronic properties of this novel two-dimensional material.

Changes induced by infestation on some chemical properties of cowpea seeds.

PubMed

Ojimelukwe, P C

2002-01-01

Three cowpea varieties were used in the present study, Insect susceptible popular variety, 'Ife-brown' (IFB), an improved variety for insect resistance IT 81D-975 (1975) and a local black cowpea variety with a white hilium adapted to diverse habitats, 'Akidi' (AKD). Cowpea seeds were infested with Callosobruchus maculatus. Crude protein content of infested and uninfested whole cowpea flour and protein concentrate was determined. Prolamin contents of flour and protein concentrates were evaluated. Fat content, free fatty acid and peroxide values of cowpea seeds were also determined. All determinations were carried out in infested and uninfested cowpea seeds in 3 replicates for each determination. Emulsion properties of cowpea seeds stored in 3 containers, plastic cans (PC) and polyethylene bags (white and black WPB/BPB) were monitored on a biweekly basis for 24 weeks. Varietal differences existed in the protein, fat and prolamin contents of cowpeas. Infestation reduced the contents of these nutrients in all cases. Free fatty acid contents and peroxide values were increased by > 100%. Infestation reduced the prolamin content by > 25% in all cases. Varietal differences also existed in emulsion capacities of cowpea flours; IFB and 975 formed better and more stable emulsions than AKD flour. Storage in plastic cans led to better retention of the emulsion properties of the cowpeas.

Direct Collapse to Supermassive Black Hole Seeds with Radiative Transfer: Isolated Halos

NASA Astrophysics Data System (ADS)

Luo, Yang; Ardaneh, Kazem; Shlosman, Isaac; Nagamine, Kentaro; Wise, John H.; Begelman, Mitchell C.

2018-05-01

Direct collapse within dark matter haloes is a promising path to form supermassive black hole seeds at high redshifts. The outer part of this collapse remains optically thin. However, the innermost region of the collapse is expected to become optically thick and requires to follow the radiation field in order to understand its evolution. So far, the adiabatic approximation has been used exclusively for this purpose. We apply radiative transfer in the flux-limited diffusion (FLD) approximation to solve the evolution of coupled gas and radiation for isolated haloes. We find that (1) the photosphere forms at 10-6 pc and rapidly expands outwards. (2) A central core forms, with a mass of 1 M⊙, supported by gas pressure gradients and rotation. (3) Growing gas and radiation pressure gradients dissolve it. (4) This process is associated with a strong anisotropic outflow; another core forms nearby and grows rapidly. (5) Typical radiation luminosity emerging from the photosphere is 5 × 1037-5 × 1038 erg s-1, of the order the Eddington luminosity. (6) Two variability time-scales are associated with this process: a long one, which is related to the accretion flow within the central 10-4-10-3 pc, and 0.1 yr, related to radiation diffusion. (7) Adiabatic models evolution differs profoundly from that of the FLD models, by forming a geometrically thick disc. Overall, an adiabatic equation of state is not a good approximation to the advanced stage of direct collapse, because the radiation is capable of escaping due to anisotropy in the optical depth and associated gradients.

The early growth of the first black holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Jarrett L.; Haardt, Francesco

With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur atmore » super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.« less

The early growth of the first black holes

DOE PAGES

Johnson, Jarrett L.; Haardt, Francesco

2016-03-04

With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur atmore » super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.« less

Quantitative approaches to information recovery from black holes

NASA Astrophysics Data System (ADS)

Balasubramanian, Vijay; Czech, Bartłomiej

2011-08-01

The evaporation of black holes into apparently thermal radiation poses a serious conundrum for theoretical physics: at face value, it appears that in the presence of a black hole, quantum evolution is non-unitary and destroys information. This information loss paradox has its seed in the presence of a horizon causally separating the interior and asymptotic regions in a black hole spacetime. A quantitative resolution of the paradox could take several forms: (a) a precise argument that the underlying quantum theory is unitary, and that information loss must be an artifact of approximations in the derivation of black hole evaporation, (b) an explicit construction showing how information can be recovered by the asymptotic observer, (c) a demonstration that the causal disconnection of the black hole interior from infinity is an artifact of the semiclassical approximation. This review summarizes progress on all these fronts.

Detection of sesame seed DNA in foods using real-time PCR.

PubMed

Brzezinski, Jennifer L

2007-04-01

The detection of potentially allergenic foods, such as sesame seeds, in food products is a major concern for the food-processing industry. A real-time PCR method was designed to determine if sesame seed DNA is present in food products. The PCR reaction amplifies a 66-bp fragment of the sesame seed 2S albumin gene, which is detected with a sesame-specific, dual-labeled TaqMan probe. This reaction will not amplify DNA derived from other seeds present in baked goods, such as pumpkin, poppy, and sunflower seeds. Additionally, this assay will not cross-react with DNA from several tree nut species, such as almond, Brazil nut, cashew, hazelnut, and walnut, as well as four varieties of peanut. This assay is sensitive enough to detect 5 pg of purified sesame seed DNA, as well as sesame seed DNA in a spiked wheat cracker sample.

The clustering of primordial black holes

NASA Astrophysics Data System (ADS)

Chisholm, James R.

2005-12-01

We investigate the spatial clustering properties of primordial black holes (PBHs). With minimal assumptions, we show that PBHs are created highly clustered. They constitute an isocurvature perturbation that is non-linear upon horizon entry. Using the peak-background split model of bias, we compute the PBH two-point correlation function and power spectrum. A consequence of this is that PBHs cannot serve as the majority of dark matter in the universe. We show that this clustering leads to PBH mergers which spoil the mass-creation time relation. We examine the prospect of PBHs being the seeds of Supermassive Black Holes as well.

Iron bioavailability and weight gains to iron-deficient rats fed a commonly consumed Tunisian meal 'bean seeds ragout' with or without beef and with green or black tea decoction.

PubMed

Hamdaoui, Mohamed Hédi; Chabchoub, Soufia; Hédhili, Abderrazek

2003-01-01

The Fe bioavailability and the weight gains were evaluated in rats fed a commonly consumed Tunisian meal 'bean seeds ragout' (BSR), with or without beef and with black or green tea decoction. The Fe bioavailability was evaluated in Fe-deficient rats by the hemoglobin repletion method and the Fe stored in the liver. The addition of beef to the BSR significantly increased the Fe bioavailability from this meal by 147% and the reserve of Fe stored in the liver by 77% (P < 0.001). In contrast, both black and green tea decoctions caused a significant decrease of the Fe bioavailability from BSR meal (-19.6 +/- 4.9% and -14.9 +/- 4.1%, respectively). The reserve of Fe stored in the liver was significantly lower in the BSR, the black and the green tea groups than in the positive control group (FeSO4). The weight gains were significantly lower in the black and the green tea groups (3.9 +/- 5.7 g, 13 +/- 1.9 g, respectively) than in the BSR group (24.9 +/- 6 g). The addition of beef to BSR meal counteracted the inhibitory effect of the kidney bean and considerably improved the Fe bioavailability and the Fe stored in the liver of rats. The green tea decoction, which constitutes an important source of antioxidant factors, had the same inhibitory effect as the black tea decoction on the Fe bioavailability from BSR meal. In addition, both black and green teas significantly reduced the weight gains, where the black tea decoction has the most effect.

Percussion as an alternative scarification for New Mexico locust and black locust seeds

Treesearch

Nabil Khadduri; John T. Harrington; Lee S. Rosner; David R. Dreesen

2002-01-01

Hot water and sulfuric acid soaks are traditional treatments for seeds of many temperate woody legumes, including locusts. However, these scarification techniques often produce inconsistent germination. Percussion scarification, where seeds are repeatedly propelled against a hard surface, was compared with hot water scarification to evaluate treatment efficacy for New...

Mutations in cauliflower and sprout broccoli grown from seeds flown in space

NASA Astrophysics Data System (ADS)

Wu, Hong; Huang, Congli; Zhang, Keping; Sun, Yeqing

2010-11-01

Cauliflower and sprout broccoli are widely planted vegetables particularly in Fujian Province, China. To study the mutation in these two types of vegetables induced from spaceflight, we flew the seeds on the 20th Chinese recoverable satellite which orbited the Earth for 18 days. After returning to the Earth, the cauliflower seeds were planted for two generations and the sprout broccoli seeds for one generation at the Xiamen Agriculture Research Institute. Of the 12 cauliflowers planted for the first generation, two showed significant phenotypical changes in both the size of the plant and the weight of the flower head. In addition, most of the space flown plants were found to be resistant to the black rot attack in the field. Cauliflowers planted for the second generation from the seeds in one of the two plants that displayed phenotypical changes in the first generation showed similar mutations. For the first generation of sprout broccoli, the rate of emergence from the flown seeds was lower than that of the control by 30%. No significant changes in the phenotype between the sprout broccolis planted from the flown seeds and the control were observed except one of the mutated sprout broccolis showed a change in the appearance in the lesser bud of the chief flower head. Results of the study demonstrated that DNA damages in some of the genes may have occurred in the seeds flown in space, and some of the changes in the genes may have inherited from the first to the second generation. The improved resistance to the black rot attack and increased size of the flower head are apparently beneficial.

Combined mass spectrometry-based metabolite profiling of different pigmented rice (Oryza sativa L.) seeds and correlation with antioxidant activities.

PubMed

Kim, Ga Ryun; Jung, Eun Sung; Lee, Sarah; Lim, Sun-Hyung; Ha, Sun-Hwa; Lee, Choong Hwan

2014-09-29

Nine varieties of pigmented rice (Oryza sativa L.) seeds that were black, red, or white were used to perform metabolite profiling by using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and gas chromatography (GC) TOF-MS, to measure antioxidant activities. Clear grouping patterns determined by the color of the rice seeds were identified in principle component analysis (PCA) derived from UPLC-Q-TOF-MS. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimer, proanthocyanidin trimer, apigenin-6-C-glugosyl-8-C-arabiboside, tricin-O-rhamnoside-O-hexoside, and lipids were identified as significantly different secondary metabolites. In PCA score plots derived from GC-TOF-MS, Jakwangdo (JKD) and Ilpoom (IP) species were discriminated from the other rice seeds by PC1 and PC2. Valine, phenylalanine, adenosine, pyruvate, nicotinic acid, succinic acid, maleic acid, malonic acid, gluconic acid, xylose, fructose, glucose, maltose, and myo-inositol were significantly different primary metabolites in JKD species, while GABA, asparagine, xylitol, and sucrose were significantly distributed in IP species. Analysis of antioxidant activities revealed that black and red rice seeds had higher activity than white rice seeds. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimers, proanthocyanidin trimers, and catechin were highly correlated with antioxidant activities, and were more plentiful in black and red rice seeds. These results are expected to provide valuable information that could help improve and develop rice-breeding techniques.

Multipole moments of bumpy black holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vigeland, Sarah J.

General relativity predicts the existence of black holes, compact objects whose spacetimes depend only on their mass, spin, and charge in vacuum (the 'no-hair' theorem). As various observations probe deeper into the strong fields of black hole candidates, it is becoming possible to test this prediction. Previous work suggested that such tests can be performed by measuring whether the multipolar structure of black hole candidates has the form that general relativity demands, and introduced a family of 'bumpy black hole' spacetimes to be used for making these measurements. These spacetimes have generalized multipoles, where the deviation from the Kerr metricmore » depends on the spacetime's 'bumpiness'. In this paper, we show how to compute the Geroch-Hansen moments of a bumpy black hole, demonstrating that there is a clean mapping between the deviations used in the bumpy black hole formalism and the Geroch-Hansen moments. We also extend our previous results to define bumpy black holes whose current moments, analogous to magnetic moments of electrodynamics, deviate from the canonical Kerr value.« less

In vitro antifungal effect of black cumin seed quinones against dairy spoilage yeasts at different acidity levels.

PubMed

Halamova, Katerina; Kokoska, Ladislav; Flesar, Jaroslav; Sklenickova, Olga; Svobodova, Blanka; Marsik, Petr

2010-12-01

The antiyeast activity of the black cumin seed (Nigella sativa) quinones dithymoquinone, thymohydroquinone (THQ), and thymoquinone (TQ) were evaluated in vitro with a broth microdilution method against six dairy spoilage yeast species. Antifungal effects of the quinones were compared with those of preservatives commonly used in milk products (calcium propionate, natamycin, and potassium sorbate) at two pH levels (4.0 and 5.5). THQ and TQ possessed significant antiyeast activity and affected the growth of all strains tested at both pH levels, with MICs ranging from 8 to 128 μg/ml. With the exception of the antibiotic natamycin, the inhibitory effects of all food preservatives against the yeast strains tested in this study were strongly affected by differences in pH, with MICs of ≥16 and ≥512 μg/ml at pH 4.0 and 5.5, respectively. These findings suggest that HQ and TQ are effective antiyeast agents that could be used in the dairy industry as chemical preservatives of natural origin.

First identification of direct collapse black hole candidates in the early Universe in CANDELS/GOODS-S

NASA Astrophysics Data System (ADS)

Pacucci, Fabio; Ferrara, Andrea; Grazian, Andrea; Fiore, Fabrizio; Giallongo, Emanuele; Puccetti, Simonetta

2016-06-01

The first black hole seeds, formed when the Universe was younger than ˜500 Myr, are recognized to play an important role for the growth of early (z ˜ 7) supermassive black holes. While progresses have been made in understanding their formation and growth, their observational signatures remain largely unexplored. As a result, no detection of such sources has been confirmed so far. Supported by numerical simulations, we present a novel photometric method to identify black hole seed candidates in deep multiwavelength surveys. We predict that these highly obscured sources are characterized by a steep spectrum in the infrared (1.6-4.5 μm), I.e. by very red colours. The method selects the only two objects with a robust X-ray detection found in the CANDELS/GOODS-S survey with a photometric redshift z ≳ 6. Fitting their infrared spectra only with a stellar component would require unrealistic star formation rates (≳2000 M⊙ yr-1). To date, the selected objects represent the most promising black hole seed candidates, possibly formed via the direct collapse black hole scenario, with predicted mass >105 M⊙. While this result is based on the best photometric observations of high-z sources available to date, additional progress is expected from spectroscopic and deeper X-ray data. Upcoming observatories, like the JWST, will greatly expand the scope of this work.

Full-Tree Skidding Favors Black Spruce Reproduction Under Certain Peatland Conditions

Treesearch

William F. Johnston

1980-01-01

Two trials on different sites indicate that clearcut black spruce reproduces well after full-tree skidding only on nonbrushy sites that have fairly abundant sphagnum seedbeds and adequate natural seeding.

How well can ultracompact bodies imitate black hole ringdowns?

NASA Astrophysics Data System (ADS)

Glampedakis, Kostas; Pappas, George

2018-02-01

The ongoing observations of merging black holes by the instruments of the fledging gravitational wave astronomy has opened the way for testing the general-relativistic Kerr black hole metric and, at the same time, for probing the existence of more speculative horizonless ultracompact objects. In this paper we quantify the difference that these two classes of objects may exhibit in the post-merger ringdown signal. By considering rotating systems in general relativity and assuming an eikonal limit and a third-order Hartle-Thorne slow-rotation approximation, we provide the first calculation of the early ringdown frequency and damping time as a function of the body's multipolar structure. Using the example of a gravastar, we show that the main ringdown signal may differ by as much as a few percent with respect to that of a Kerr black hole, a deviation that could be probed by near-future Advanced LIGO/Virgo searches.

The impact of black seed oil on tramadol-induced hepatotoxicity: Immunohistochemical and ultrastructural study.

PubMed

Omar, Nesreen Moustafa; Mohammed, Mohammed Amin

2017-06-01

The natural herb, black seed (Nigella Sativa; NS) is one of the most important elements of folk medicine. The aim was to evaluate the impact of Nigella Sativa Oil (NSO) on the changes induced by tramadol in rat liver. Twenty four albino rats were used. given intraperitoneal and oral saline for 30days. TR-group: given intraperitoneal tramadol (20, 40, 80mg/kg/day) in the first, middle and last 10days of the experiment, respectively. TR+NS group: administered intraperitoneal tramadol in similar doses to TR-group plus oral NSO (4ml/kg/day) for 30days. Immunohistochemical, electron microscopic, biochemical and statistical studies were performed. TR-group displayed disarranged hepatic architecture, hepatic congestion, hemorrhage and necrosis. Apoptotic hepatocytes, mononuclear cellular infiltration and a significant increase in the number of anti-CD68 positive cells were observed. Ultrastructurally, hepatocytes showed shrunken nuclei, swollen mitochondria, many lysosomes and autophagic vacuoles. Activated Ito and Von Kupffer cells were also demonstrated. Elevated serum levels of AST, ALT, ALP and bilirubin were noticed. NSO administration resulted in preservation of hepatic histoarchitecture and ultrastructure and significant reductions in the number of anti-CD68 positive cells and serum levels of liver seromarkers. In conclusion, NSO administration could mitigate the alterations induced by tramadol in rat liver. Copyright © 2017 Elsevier GmbH. All rights reserved.

Black holes and the multiverse

NASA Astrophysics Data System (ADS)

Garriga, Jaume; Vilenkin, Alexander; Zhang, Jun

2016-02-01

Vacuum bubbles may nucleate and expand during the inflationary epoch in the early universe. After inflation ends, the bubbles quickly dissipate their kinetic energy; they come to rest with respect to the Hubble flow and eventually form black holes. The fate of the bubble itself depends on the resulting black hole mass. If the mass is smaller than a certain critical value, the bubble collapses to a singularity. Otherwise, the bubble interior inflates, forming a baby universe, which is connected to the exterior FRW region by a wormhole. A similar black hole formation mechanism operates for spherical domain walls nucleating during inflation. As an illustrative example, we studied the black hole mass spectrum in the domain wall scenario, assuming that domain walls interact with matter only gravitationally. Our results indicate that, depending on the model parameters, black holes produced in this scenario can have significant astrophysical effects and can even serve as dark matter or as seeds for supermassive black holes. The mechanism of black hole formation described in this paper is very generic and has important implications for the global structure of the universe. Baby universes inside super-critical black holes inflate eternally and nucleate bubbles of all vacua allowed by the underlying particle physics. The resulting multiverse has a very non-trivial spacetime structure, with a multitude of eternally inflating regions connected by wormholes. If a black hole population with the predicted mass spectrum is discovered, it could be regarded as evidence for inflation and for the existence of a multiverse.

Black holes and the multiverse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garriga, Jaume; Vilenkin, Alexander; Zhang, Jun, E-mail: jaume.garriga@ub.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: jun.zhang@tufts.edu

Vacuum bubbles may nucleate and expand during the inflationary epoch in the early universe. After inflation ends, the bubbles quickly dissipate their kinetic energy; they come to rest with respect to the Hubble flow and eventually form black holes. The fate of the bubble itself depends on the resulting black hole mass. If the mass is smaller than a certain critical value, the bubble collapses to a singularity. Otherwise, the bubble interior inflates, forming a baby universe, which is connected to the exterior FRW region by a wormhole. A similar black hole formation mechanism operates for spherical domain walls nucleatingmore » during inflation. As an illustrative example, we studied the black hole mass spectrum in the domain wall scenario, assuming that domain walls interact with matter only gravitationally. Our results indicate that, depending on the model parameters, black holes produced in this scenario can have significant astrophysical effects and can even serve as dark matter or as seeds for supermassive black holes. The mechanism of black hole formation described in this paper is very generic and has important implications for the global structure of the universe. Baby universes inside super-critical black holes inflate eternally and nucleate bubbles of all vacua allowed by the underlying particle physics. The resulting multiverse has a very non-trivial spacetime structure, with a multitude of eternally inflating regions connected by wormholes. If a black hole population with the predicted mass spectrum is discovered, it could be regarded as evidence for inflation and for the existence of a multiverse.« less

The astrophysical science case for a decihertz gravitational-wave detector

NASA Astrophysics Data System (ADS)

Mandel, Ilya; Sesana, Alberto; Vecchio, Alberto

2018-03-01

We discuss the astrophysical science case for a decihertz gravitational-wave mission. We focus on unique opportunities for scientific discovery in this frequency range, including probes of type IA supernova progenitors, mergers in the presence of third bodies, intermediate mass black holes, seeds of massive black holes, improved sky localization, and tracking the population of merging compact binaries.

Observational Corollaries of Proto-AGN: Understanding Formation of Supermassive Black Hole Seeds

NASA Astrophysics Data System (ADS)

Shlosman, Isaac

2016-10-01

Formation of supermassive black holes (SMBHs) is still an enigma. Recent detections of high-z quasars which harbor massive SMBHs provide a challenge to models of structure buildup in the universe. Main alternatives for the formation of SMBH seeds are (1) remnants of Population III stars, and (2) a direct baryonic collapse within dark matter (DM) halos of 10^8 Mo -- first halos whose virial temperature exceeds 10^4 K, and which can lead to the formation of proto-AGN -- luminous pre-SMBH objects. Potentially, this can involve both high-z objects as well as low-z dwarf galaxies in voids. We focus on the direct collapse in 10^8 Mo halos which circumvents the pitfalls of Pop III remnants. The collapse can proceed via a radiation pressure-supported quasistar -- with a modified blackbody continuum. Such a configuration requires a very efficient angular momentum transfer. Or, it can form a thick, differentially rotating, self-gravitating disk, which is associated with an X-ray-infrared continuum and Seyfert-level luminosity, anisotropic emission, massive bi-conical outflows, and will be a powerful source of the Ly-alpha emission. We propose to perform radiative transfer in the continuum and hydrogen lines (e.g., Lyman and Balmer), using our models of proto-AGN, and do it on-the-fly -- concurrently with the collapse. We shall test the path to quasistellar and disky proto-AGN, produce first synthetic spectra of proto-AGN, and address the issue of feasibility of their detection by the JWST. Finally, we shall develop the strategy of searching for these objects at high- and low-z, based on the specific features in the spectra and associated variability.

Machine vision system for inspecting characteristics of hybrid rice seed

NASA Astrophysics Data System (ADS)

Cheng, Fang; Ying, Yibin

2004-03-01

Obtaining clear images advantaged of improving the classification accuracy involves many factors, light source, lens extender and background were discussed in this paper. The analysis of rice seed reflectance curves showed that the wavelength of light source for discrimination of the diseased seeds from normal rice seeds in the monochromic image recognition mode was about 815nm for jinyou402 and shanyou10. To determine optimizing conditions for acquiring digital images of rice seed using a computer vision system, an adjustable color machine vision system was developed. The machine vision system with 20mm to 25mm lens extender produce close-up images which made it easy to object recognition of characteristics in hybrid rice seeds. White background was proved to be better than black background for inspecting rice seeds infected by disease and using the algorithms based on shape. Experimental results indicated good classification for most of the characteristics with the machine vision system. The same algorithm yielded better results in optimizing condition for quality inspection of rice seed. Specifically, the image processing can correct for details such as fine fissure with the machine vision system.

Skyrmion black hole hair: Conservation of baryon number by black holes and observable manifestations

NASA Astrophysics Data System (ADS)

Dvali, Gia; Gußmann, Alexander

2016-12-01

We show that the existence of black holes with classical skyrmion hair invalidates standard proofs that global charges, such as the baryon number, cannot be conserved by a black hole. By carefully analyzing the standard arguments based on a Gedankenexperiment in which a black hole is seemingly-unable to return the baryon number that it swallowed, we identify inconsistencies in this reasoning, which does not take into the account neither the existence of skyrmion black holes nor the baryon/skyrmion correspondence. We then perform a refined Gedankenexperiment by incorporating the new knowledge and show that no contradiction with conservation of baryon number takes place at any stage of black hole evolution. Our analysis also indicates no conflict between semi-classical black holes and the existence of baryonic gauge interaction arbitrarily-weaker than gravity. Next, we study classical cross sections of a minimally-coupled massless probe scalar field scattered by a skyrmion black hole. We investigate how the skyrmion hair manifests itself by comparing this cross section with the analogous cross section caused by a Schwarzschild black hole which has the same ADM mass as the skyrmion black hole. Here we find an order-one difference in the positions of the characteristic peaks in the cross sections. The peaks are shifted to smaller scattering angles when the skyrmion hair is present. This comes from the fact that the skyrmion hair changes the near horizon geometry of the black hole when compared to a Schwarzschild black hole with same ADM mass. We keep the study of this second aspect general so that the qualitative results which we obtain can also be applied to black holes with classical hair of different kind.

Differential accumulation of polyphenolics in black bean genotypes grown in four environments.

PubMed

Marles, M A Susan; Balasubramanian, Parthiba; Bett, Kirstin E

2010-06-09

Environmental effects on polyphenolic composition of pigmented seed coat tissue were examined in four black bean genotypes, grown in four locations in Canada. Genotype was the most significant determinant in the phenotypic expression of flavonoid traits across four locations (p < 0.0001). The genotype x environment interaction was not significantly different for anthocyanin or extractable condensed tannin (syn. proanthocyanidin) but was significant for the bound anthocyanidin concentration (p < 0.05). One trace metabolite, (-)-epicatechin, was identified, but no flavonols were detected in the seed coats. Sequestration of anthocyanin in the seed coat was genotype-dependent and predominantly consisted of delphinidin with lesser amounts of petunidin and malvidin. Pigment sequestration in the two integument layers of the seed coat appeared to be mutually exclusive across all genotypes in terms of the pigment chemical character. Tissue-specific accumulation of extractable and bound anthocyanin in the outer integument was observed. The inner integument was devoid of anthocyanin, and the pigment consisted solely of condensed tannin inclusions. The occurrence of condensed tannin together with anthocyanin pigments, whether extractable or bound either by oxidation or by cross-linking, influenced the visual uniformity of seeds of bean cultivars. The co-occurrence of these compounds could have an effect on postharvest appearance during storage, on canning quality, and on the dietary effects of the putative functional food profile in the black bean market class.

Natural occurrence of ochratoxin A contamination in commercial black and white pepper products.

PubMed

Jalili, M; Jinap, S; Radu, S

2010-10-01

The concentration of ochratoxin A (OTA) in 120 commercial pepper (84 pre-packed and 36 bulk samples), which consist of local and imported white and black pepper in powder and seed form in Malaysia were determined. The objective of the study was to investigate and compare OTA concentration in black pepper and white pepper being commercialized in Malaysia. Determination method was based on HPLC with fluorescence detection coupled with immunoaffinity column clean-up step. Mobile phase consisted of acetonitrile-water-acetic acid (49.5:49.5:1.0, v/v/v), and flow rate was 1 ml/min. The LOD was 0.02 ng/g, and the average recovery values of OTA ranged from 79.5 to 92.0% in black pepper and 81.2-90.3% in white pepper. A total of 57 samples (47.5%) were contaminated with OTA ranging from 0.15 to 13.58 ng/g. The results showed that there was a significant difference between type of pepper and brands. OTA concentration in black pepper was significantly higher than white pepper (p < 0.05). The highest concentration of ochratoxin, 13.58 ng/g, was detected in a sample of black pepper seed followed by 12.64 ng/g in a sample of black pepper powder, both were bulk samples purchased from open market.

Intraoperative 3D Navigation for Single or Multiple 125I-Seed Localization in Breast-Preserving Cancer Surgery.

PubMed

Pouw, Bas; de Wit-van der Veen, Linda J; van Duijnhoven, Frederieke; Rutgers, Emiel J Th; Stokkel, Marcel P M; Valdés Olmos, Renato A; Vrancken Peeters, Marie-Jeanne T F D

2016-05-01

Mammographic screening has led to the identification of more women with nonpalpable breast cancer, many of them to be treated with breast-preserving surgery. To accomplish radical tumor excision, adequate localization techniques such as radioactive seed localization (RSL) are required. For RSL, a radioactive I-seed is implanted central in the tumor to enable intraoperative localization using a γ-probe. In case of extensive tumor or multifocal carcinoma, multiple I-seeds can be used to delineate the involved area. Preoperative imaging is performed different from surgical positioning; therefore, exact I-seed depth remains unknown during surgery. Twenty patients (mean age, 56.8 years) with 25 implanted I-seeds scheduled for RSL were included. Sixteen patients had 1 I-seed implanted in the primary lesion, 3 patients had 2 I-seeds, and 1 patient had 3 I-seeds. Freehand SPECT localized I-seeds by measuring γ-counts from different directions, all registered by an optical tracking system. A reconstruction and visualization algorithm enabled 3-dimensional (3D) navigation toward the I-seeds. Freehand SPECT visualized all I-seeds in primary tumors and provided preincision depth information. The deviation, mean (SD), between the freehand SPECT depth and the surgical depth estimation was 1.9 (2.1) mm (range, 0-7 mm). Three-dimensional freehand SPECT was especially useful identifying multiple implanted I-seeds because the conventional γ-probe has more difficulty discriminating I-seeds transcutaneous. Freehand SPECT with 3D navigation is a valuable tool in RSL for both single and multiple implanted I-seeds in breast-preserving cancer surgery. Freehand SPECT provides continuous updating 3D imaging with information about depth and location of the I-seeds contributing to adequate excision of nonpalpable breast cancer.

Formation of massive black holes in galactic nuclei: runaway tidal encounters

NASA Astrophysics Data System (ADS)

Stone, Nicholas C.; Küpper, Andreas H. W.; Ostriker, Jeremiah P.

2017-06-01

Nuclear star clusters (NSCs) and supermassive black holes (SMBHs) both inhabit galactic nuclei, coexisting in a range of bulge masses, but excluding each other in the largest or smallest galaxies. We propose that the transformation of NSCs into SMBHs occurs via runaway tidal captures, once NSCs exceed a certain critical central density and velocity dispersion. The bottleneck in this process is growing the first e-fold in black hole mass. The growth of a stellar mass black hole past this bottleneck occurs as tidally captured stars are consumed in repeated episodes of mass transfer at pericentre. Tidal captures may deactivate as a growth channel once the black hole mass ≳102-3 M⊙, but tidal disruption events will continue and can grow the seed SMBH to larger sizes. The runaway slows (becomes subexponential) once the seed SMBH consumes the core of its host NSC. While most of the cosmic mass density in SMBHs is ultimately produced by episodic gaseous accretion in very massive galaxies, the smallest SMBHs have probably grown from strong tidal encounters with NSC stars. SMBH seeds that grow for a time t entirely through this channel will follow simple power-law relations with the velocity dispersion, σ, of their host galaxy. In the simplest regime, it is M_\\bullet ˜ σ ^{3/2}√{M_\\star t / G} ˜ 106 M_{⊙} (σ / 50 {km s}^{-1})^{3/2}(t/10^{10} yr)^{1/2}, but the exponents and pre-factor can differ slightly depending on the details of loss cone refilling. Current tidal disruption event rates predicted from this mechanism are consistent with observations.

Integrated transrectal probe for translational ultrasound-photoacoustic imaging

NASA Astrophysics Data System (ADS)

Bell, Kevan L.; Harrison, Tyler; Usmani, Nawaid; Zemp, Roger J.

2016-03-01

A compact photoacoustic transrectal probe is constructed for improved imaging in brachytherapy treatment. A 192 element 5 MHz linear transducer array is mounted inside a small 3D printed casing along with an array of optical fibers. The device is fed by a pump laser and tunable NIR-optical parametric oscillator with data collected by a Verasonics ultrasound platform. This assembly demonstrates improved imaging of brachytherapy seeds in phantoms with depths up to 5 cm. The tuneable excitation in combination with standard US integration provides adjustable contrast between the brachytherapy seeds, blood filled tubes and background tissue.

Characterisation of phenolics, betanins and antioxidant activities in seeds of three Chenopodium quinoa Willd. genotypes.

PubMed

Tang, Yao; Li, Xihong; Zhang, Bing; Chen, Peter X; Liu, Ronghua; Tsao, Rong

2015-01-01

Quinoa (Chenopodium quinoa Willd.) is known for its exceptional nutritional value and potential health benefits. The present study identified the composition of different forms of extractable phenolics and betacyanins of quinoa cultivars in white, red and black, and how they contribute to antioxidant activities. Results showed that at least 23 phenolic compounds were found in either free or conjugated forms (liberated by alkaline and/or acid hydrolysis); the majority of which were phenolic acids, mainly vanillic acid, ferulic acid and their derivatives as well as main flavonoids quercetin, kaempferol and their glycosides. Betacyanins, mainly betanin and isobetanin, were confirmed for the first time to be the pigments of the red and black quinoa seeds, instead of anthocyanins. Darker quinoa seeds had higher phenolic concentration and antioxidant activity. Findings of these phenolics, along with betacyanins in this study add new knowledge to the functional components of quinoa seeds of different cultivar background. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Effect of Carbon Black on Elastomer Blends

NASA Astrophysics Data System (ADS)

Si, Mayu; Koga, Tadanori; Ji, Yuan; Seo, Young-Soo; Rafailovich, Miriam; Sokolov, Jonathan; Gerspacher, M.; Dias, A. J.; Karp, Kriss R.; Satija, Sushil; Lin, Min Y.

2003-03-01

The effects of untreated and heat-treated carbon black N299 on the interfacial properties of PB (Polybutadiene) and terpolymer BIMS [brominated Poly(isobutylene-co-methyl styrene)] were investigated by neutron reflectivity (NR) and lateral force microscopy (LFM). The NR results show that the addition of carbon black significantly slows down the interfacial broadening while heat-treated carbon black has less effect on slowing down the diffusion compared with untreated carbon black. These results were confirmed by the LFM data, which shows the magnitude of lateral force loop of heat-treated carbon black is bigger than that of untreated one. Ultra small and small angle neutron scattering (USANS and SANS) were used to probe the morphology and surface lateral force. Increasing volume concentration of carbon black to 5glass transition temperature of BIMS is also decreased, which was measured by Differential scanning Calorimeter (DSC). XRD analysis indicates that the heat treatment crystallizes the carbon black and strong graphitic peaks are observed. The large degree of crystallization decreases the interaction with the polymer matrix and hence minimizes the effect on the internal dynamics

Magnitude Differences in Bioactive Compounds, Chemical Functional Groups, Fatty Acid Profiles, Nutrient Degradation and Digestion, Molecular Structure, and Metabolic Characteristics of Protein in Newly Developed Yellow-Seeded and Black-Seeded Canola Lines.

PubMed

Theodoridou, Katerina; Zhang, Xuewei; Vail, Sally; Yu, Peiqiang

2015-06-10

Recently, new lines of yellow-seeded (CS-Y) and black-seeded canola (CS-B) have been developed with chemical and structural alteration through modern breeding technology. However, no systematic study was found on the bioactive compounds, chemical functional groups, fatty acid profiles, inherent structure, nutrient degradation and absorption, or metabolic characteristics between the newly developed yellow- and black-seeded canola lines. This study aimed to systematically characterize chemical, structural, and nutritional features in these canola lines. The parameters accessed include bioactive compounds and antinutrition factors, chemical functional groups, detailed chemical and nutrient profiles, energy value, nutrient fractions, protein structure, degradation kinetics, intestinal digestion, true intestinal protein supply, and feed milk value. The results showed that the CS-Y line was lower (P ≤ 0.05) in neutral detergent fiber (122 vs 154 g/kg DM), acid detergent fiber (61 vs 99 g/kg DM), lignin (58 vs 77 g/kg DM), nonprotein nitrogen (56 vs 68 g/kg DM), and acid detergent insoluble protein (11 vs 35 g/kg DM) than the CS-B line. There was no difference in fatty acid profiles except C20:1 eicosenoic acid content (omega-9) which was in lower in the CS-Y line (P < 0.05) compared to the CS-B line. The glucosinolate compounds differed (P < 0.05) in terms of 4-pentenyl, phenylethyl, 3-CH3-indolyl, and 3-butenyl glucosinolates (2.9 vs 1.0 μmol/g) between the CS-Y and CS-B lines. For bioactive compounds, total polyphenols tended to be different (6.3 vs 7.2 g/kg DM), but there were no differences in erucic acid and condensed tannins with averages of 0.3 and 3.1 g/kg DM, respectively. When protein was portioned into five subfractions, significant differences were found in PA, PB1 (65 vs 79 g/kg CP), PB2, and PC fractions (10 vs 33 g/kg CP), indicating protein degradation and supply to small intestine differed between two new lines. In terms of protein structure spectral

Accomplishments of the Oak Ridge National Laboratory Seed Money program

DOE R&D Accomplishments Database

1986-09-01

In 1974, a modest program for funding new, innovative research was initiated at ORNL. It was called the "Seed Money" program and has become part of a larger program, called Exploratory R and D, which is being carried out at all DOE national laboratories. This report highlights 12 accomplishments of the Seed Money Program: nickel aluminide, ion implantation, laser annealing, burn meter, Legionnaires' disease, whole-body radiation counter, the ANFLOW system, genetics and molecular biology, high-voltage equipment, microcalorimeter, positron probe, and atom science. (DLC)

Thermal Changes of Maize Seed by Laser Irradiation

NASA Astrophysics Data System (ADS)

Hernandez-Aguilar, C.; Dominguez-Pacheco, A.; Cruz-Orea, A.

2015-09-01

In this research, the thermal evolution in maize seeds ( Zea mays L.) was studied when low-intensity laser irradiation was applied during 60 s. The seeds were irradiated in three different conditions: suspended in air, placed on an aluminum surface, and finally placed on a cardboard; the evolution of the seed temperature was measured by an infrared camera. Photoacoustic spectroscopy and the Rosencwaig and Gersho model were used to determine the optical absorption coefficient (β ) of the seeds. The results indicate that using 650 nm laser light and 27.4 mW, it is possible to produce temperature changes (up to 9.06°C after 1 min) on the seeds. Comparing the mean temperature of the seeds, during and after the incidence of light from a laser, it was found that there were statistically significant differences (P≤ 0.05) from time t1 to time t_{16} (t1 to t_{16}) and t3 to t_{16}, for the laser turned on and off, respectively. The seed condition that had the highest temperature variation, relative to the initial temperature (during the irradiation laser exposure), involved the seeds suspended in air. With regard to the stage of decay of the temperature, it was found that the seed condition that decays more slowly was the seed placed on the cardboard. It was also found that black-dyed maize seeds are optically opaque in the 300 nm to 700 nm range Also, the thermal diffusion length is smaller than the optical penetration length. In the present investigation, it was shown that there is a thermal component associated with the mechanisms of laser biostimulation, which is also a function of the container materials of the seed. In this way, the effects of laser treatment on maize seeds involve at least a temperature effect. It is important to know the temperature changes in the seeds that have been irradiated with a laser beam since they could have substantial practical and theoretical importance.

Black-hole Merger Simulations for LISA Science

NASA Technical Reports Server (NTRS)

Kelly, Bernard J.; Baker, John G.; vanMeter, James R.; Boggs, William D.; Centrella, Joan M.; McWilliams, Sean T.

2009-01-01

The strongest expected sources of gravitational waves in the LISA band are the mergers of massive black holes. LISA may observe these systems to high redshift, z>10, to uncover details of the origin of massive black holes, and of the relationship between black holes and their host structures, and structure formation itself. These signals arise from the final stage in the development of a massive black-hole binary emitting strong gravitational radiation that accelerates the system's inspiral toward merger. The strongest part of the signal, at the point of merger, carries much information about the system and provides a probe of extreme gravitational physics. Theoretical predictions for these merger signals rely on supercomputer simulations to solve Einstein's equations. We discuss recent numerical results and their impact on LISA science expectations.

Divergence in Life History Traits between Two Populations of a Seed-Dimorphic Halophyte in Response to Soil Salinity

PubMed Central

Yang, Fan; Baskin, Jerry M.; Baskin, Carol C.; Yang, Xuejun; Cao, Dechang; Huang, Zhenying

2017-01-01

Production of heteromorphic seeds is common in halophytes growing in arid environments with strong spatial and temporal heterogeneity. However, evidence for geographic variation (reflecting local adaptation) is almost nonexistent. Our primary aims were to compare the life history traits of two desert populations of this halophytic summer annual Suaeda corniculata subsp. mongolica and to investigate the phenotypic response of its plant and heteromorphic seeds to different levels of salt stress. Dimorphic seeds (F1) of the halophyte S. corniculata collected from two distant populations (F0) that differ in soil salinity were grown in a common environment under different levels of salinity to minimize the carryover effects from the field environment and tested for variation in plant (F1) and seed (F2) traits. Compared to F1 plants grown in low soil salinity, those grown in high salinity (>0.2 mol⋅L-1) were smaller and produced fewer seeds but had a higher reproductive allocation and a higher non-dormant brown seed: dormant black seed ratio. High salinity during plant growth decreased germination percentage of F2 black seeds but had no effect on F2 brown seeds. Between population differences in life history traits in the common environment corresponded with those in the natural populations. Phenotypic differences between the two populations were retained in F1 plants and in F2 seeds in the common environment, which suggests that the traits are genetically based. Our results indicate that soil salinity plays an ecologically important role in population regeneration of S. corniculata by influencing heteromorphic seed production in the natural habitat. PMID:28670319

Ice-Borehole Probe

NASA Technical Reports Server (NTRS)

Behar, Alberto; Carsey, Frank; Lane, Arthur; Engelhardt, Herman

2006-01-01

An instrumentation system has been developed for studying interactions between a glacier or ice sheet and the underlying rock and/or soil. Prior borehole imaging systems have been used in well-drilling and mineral-exploration applications and for studying relatively thin valley glaciers, but have not been used for studying thick ice sheets like those of Antarctica. The system includes a cylindrical imaging probe that is lowered into a hole that has been bored through the ice to the ice/bedrock interface by use of an established hot-water-jet technique. The images acquired by the cameras yield information on the movement of the ice relative to the bedrock and on visible features of the lower structure of the ice sheet, including ice layers formed at different times, bubbles, and mineralogical inclusions. At the time of reporting the information for this article, the system was just deployed in two boreholes on the Amery ice shelf in East Antarctica and after successful 2000 2001 deployments in 4 boreholes at Ice Stream C, West Antarctica, and in 2002 at Black Rapids Glacier, Alaska. The probe is designed to operate at temperatures from 40 to +40 C and to withstand the cold, wet, high-pressure [130-atm (13.20-MPa)] environment at the bottom of a water-filled borehole in ice as deep as 1.6 km. A current version is being outfitted to service 2.4-km-deep boreholes at the Rutford Ice Stream in West Antarctica. The probe (see figure) contains a sidelooking charge-coupled-device (CCD) camera that generates both a real-time analog video signal and a sequence of still-image data, and contains a digital videotape recorder. The probe also contains a downward-looking CCD analog video camera, plus halogen lamps to illuminate the fields of view of both cameras. The analog video outputs of the cameras are converted to optical signals that are transmitted to a surface station via optical fibers in a cable. Electric power is supplied to the probe through wires in the cable at a

Event Horizon Telescope observations as probes for quantum structure of astrophysical black holes

NASA Astrophysics Data System (ADS)

Giddings, Steven B.; Psaltis, Dimitrios

2018-04-01

The need for a consistent quantum evolution for black holes has led to proposals that their semiclassical description is modified not just near the singularity, but at horizon or larger scales. If such modifications extend beyond the horizon, they influence regions accessible to distant observation. Natural candidates for these modifications behave like metric fluctuations, with characteristic length scales and timescales set by the horizon radius. We investigate the possibility of using the Event Horizon Telescope to observe these effects, if they have a strength sufficient to make quantum evolution consistent with unitarity, without introducing new scales. We find that such quantum fluctuations can introduce a strong time dependence for the shape and size of the shadow that a black hole casts on its surrounding emission. For the black hole in the center of the Milky Way, detecting the rapid time variability of its shadow will require nonimaging timing techniques. However, for the much larger black hole in the center of the M87 galaxy, a variable black-hole shadow, if present with these parameters, would be readily observable in the individual snapshots that will be obtained by the Event Horizon Telescope.

Scattering of massless scalar waves by magnetically charged black holes in Einstein-Yang-Mills-Higgs theory

NASA Astrophysics Data System (ADS)

Gußmann, Alexander

2017-03-01

The existence of the classical black hole solutions of the Einstein-Yang-Mills-Higgs equations with non-Abelian Yang-Mills-Higgs hair implies that not all classical stationary magnetically charged black holes can be uniquely described by their asymptotic characteristics. In fact, in a certain domain of parameters, there exist different spherically-symmetric, non-rotating and asymptotically-flat classical black hole solutions of the Einstein-Yang-Mills-Higgs equations which have the same ADM mass and the same magnetic charge but significantly different geometries in the near-horizon regions. (These are black hole solutions which are described by a Reissner-Nordström metric on the one hand and the black hole solutions with non-Abelian Yang-Mills-Higgs hair which are described by a metric which is not of Reissner-Nordström form on the other hand). One can experimentally distinguish such black holes with the same asymptotic characteristics but different near-horizon geometries classically by probing the near-horizon regions of the black holes. We argue that one way to probe the near-horizon region of a black hole which allows one to distinguish magnetically charged black holes with the same asymptotic characteristics but different near-horizon geometries is by classical scattering of waves. Using the example of a minimally-coupled massless probe scalar field scattered by magnetically charged black holes which can be obtained as solutions of the Einstein-Yang-Mills-Higgs equations with a Higgs triplet and gauge group SU(2) in the limit of an infinite Higgs self-coupling constant we show how, in this case, the scattering cross sections differ for the magnetically charged black holes with different near-horizon geometries but the same asymptotic characteristics. We find in particular that the characteristic glory peaks in the cross sections are located at different scattering angles.

The direct collapse of a massive black hole seed under the influence of an anisotropic Lyman-Werner source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Regan, John A.; Johansson, Peter H.; Wise, John H., E-mail: john.regan@helsinki.fi

2014-11-10

The direct collapse model of supermassive black hole seed formation requires that the gas cools predominantly via atomic hydrogen. To this end we simulate the effect of an anisotropic radiation source on the collapse of a halo at high redshift. The radiation source is placed at a distance of 3 kpc (physical) from the collapsing object and is set to emit monochromatically in the center of the Lyman-Werner (LW) band. The LW radiation emitted from the high redshift source is followed self-consistently using ray tracing techniques. Due to self-shielding, a small amount of H{sub 2} is able to form atmore » the very center of the collapsing halo even under very strong LW radiation. Furthermore, we find that a radiation source, emitting >10{sup 54} (∼ 10{sup 3} J{sub 21}) photons s{sup –1}, is required to cause the collapse of a clump of M ∼ 10{sup 5} M {sub ☉}. The resulting accretion rate onto the collapsing object is ∼0.25 M {sub ☉} yr{sup –1}. Our results display significant differences, compared to the isotropic radiation field case, in terms of the H{sub 2} fraction at an equivalent radius. These differences will significantly affect the dynamics of the collapse. With the inclusion of a strong anisotropic radiation source, the final mass of the collapsing object is found to be M ∼ 10{sup 5} M {sub ☉}. This is consistent with predictions for the formation of a supermassive star or quasi-star leading to a supermassive black hole.« less

Union Troubles on Campus; Seed Money for Black Colleges

ERIC Educational Resources Information Center

Langway, Lynn; And Others

1978-01-01

Most major universities have resisted the pull of union fever. Some have not and others are giving way. Here is a short review of the development of faculty unions in higher education. Also describes the efforts of the United Negro College Fund in developing a loan program designed to help black colleges survive the rising cost of education. (R K)

Precipitation formation from orographic cloud seeding.

PubMed

French, Jeffrey R; Friedrich, Katja; Tessendorf, Sarah A; Rauber, Robert M; Geerts, Bart; Rasmussen, Roy M; Xue, Lulin; Kunkel, Melvin L; Blestrud, Derek R

2018-02-06

Throughout the western United States and other semiarid mountainous regions across the globe, water supplies are fed primarily through the melting of snowpack. Growing populations place higher demands on water, while warmer winters and earlier springs reduce its supply. Water managers are tantalized by the prospect of cloud seeding as a way to increase winter snowfall, thereby shifting the balance between water supply and demand. Little direct scientific evidence exists that confirms even the basic physical hypothesis upon which cloud seeding relies. The intent of glaciogenic seeding of orographic clouds is to introduce aerosol into a cloud to alter the natural development of cloud particles and enhance wintertime precipitation in a targeted region. The hypothesized chain of events begins with the introduction of silver iodide aerosol into cloud regions containing supercooled liquid water, leading to the nucleation of ice crystals, followed by ice particle growth to sizes sufficiently large such that snow falls to the ground. Despite numerous experiments spanning several decades, no direct observations of this process exist. Here, measurements from radars and aircraft-mounted cloud physics probes are presented that together show the initiation, growth, and fallout to the mountain surface of ice crystals resulting from glaciogenic seeding. These data, by themselves, do not address the question of cloud seeding efficacy, but rather form a critical set of observations necessary for such investigations. These observations are unambiguous and provide details of the physical chain of events following the introduction of glaciogenic cloud seeding aerosol into supercooled liquid orographic clouds.

Modelling Gravitational Radiation from Binary Black Holes

NASA Technical Reports Server (NTRS)

Centrella, Joan

2006-01-01

The final merger and coalescence of binary black holes is a key source of strong gravitational waves for the LISA mission. Observing these systems will allow us to probe the formation of cosmic structure to high redshifts and test general relativity directly in the strong-field, dynamical regime. Recently, major breakthroughs have been made in modeling black hole mergers using numerical relativity. This talk will survey these exciting developments, focusing on the gravitational waveforms and the recoil kicks produced from non-equal mass mergers.

Post-Kerr black hole spectroscopy

NASA Astrophysics Data System (ADS)

Glampedakis, Kostas; Pappas, George; Silva, Hector O.; Berti, Emanuele

2017-09-01

One of the central goals of the newborn field of gravitational wave astronomy is to test gravity in the highly nonlinear, strong field regime characterizing the spacetime of black holes. In particular, "black hole spectroscopy" (the observation and identification of black hole quasinormal mode frequencies in the gravitational wave signal) is expected to become one of the main tools for probing the structure and dynamics of Kerr black holes. In this paper we take a significant step toward that goal by constructing a "post-Kerr" quasinormal mode formalism. The formalism incorporates a parametrized but general perturbative deviation from the Kerr metric and exploits the well-established connection between the properties of the spacetime's circular null geodesics and the fundamental quasinormal mode to provide approximate, eikonal limit formulas for the modes' complex frequencies. The resulting algebraic toolkit can be used in waveform templates for ringing black holes with the purpose of measuring deviations from the Kerr metric. As a first illustrative application of our framework, we consider the Johannsen-Psaltis deformed Kerr metric and compute the resulting deviation in the quasinormal mode frequency relative to the known Kerr result.

Intermediate mass black holes in AGN discs - I. Production and growth

NASA Astrophysics Data System (ADS)

McKernan, B.; Ford, K. E. S.; Lyra, W.; Perets, H. B.

2012-09-01

Here we propose a mechanism for efficiently growing intermediate mass black holes (IMBH) in discs around supermassive black holes. Stellar mass objects can efficiently agglomerate when facilitated by the gas disc. Stars, compact objects and binaries can migrate, accrete and merge within discs around supermassive black holes. While dynamical heating by cusp stars excites the velocity dispersion of nuclear cluster objects (NCOs) in the disc, gas in the disc damps NCO orbits. If gas damping dominates, NCOs remain in the disc with circularized orbits and large collision cross-sections. IMBH seeds can grow extremely rapidly by collisions with disc NCOs at low relative velocities, allowing for super-Eddington growth rates. Once an IMBH seed has cleared out its feeding zone of disc NCOs, growth of IMBH seeds can become dominated by gas accretion from the active galactic nucleus (AGN) disc. However, the IMBH can migrate in the disc and expand its feeding zone, permitting a super-Eddington accretion rate to continue. Growth of IMBH seeds via NCO collisions is enhanced by a pile-up of migrators. We highlight the remarkable parallel between the growth of IMBH in AGN discs with models of giant planet growth in protoplanetary discs. If an IMBH becomes massive enough it can open a gap in the AGN disc. IMBH migration in AGN discs may stall, allowing them to survive the end of the AGN phase and remain in galactic nuclei. Our proposed mechanisms should be more efficient at growing IMBH in AGN discs than the standard model of IMBH growth in stellar clusters. Dynamical heating of disc NCOs by cusp stars is transferred to the gas in an AGN disc helping to maintain the outer disc against gravitational instability. Model predictions, observational constraints and implications are discussed in a companion paper (Paper II).

Association mapping of seed and disease resistance traits in Theobroma cacao L.

PubMed

Motilal, Lambert A; Zhang, Dapeng; Mischke, Sue; Meinhardt, Lyndel W; Boccara, Michel; Fouet, Olivier; Lanaud, Claire; Umaharan, Pathmanathan

2016-12-01

Microsatellite and single nucleotide polymorphism markers that could be used in marker assisted breeding of cacao were identified for number of filled seeds, black pod resistance and witches' broom disease resistance. An association mapping approach was employed to identify markers for seed number and resistance to black pod and witches' broom disease (WBD) in cacao (Theobroma cacao L.). Ninety-five microsatellites (SSRs) and 775 single nucleotide polymorphisms (SNPs) were assessed on 483 unique trees in the International Cocoa Genebank Trinidad (ICGT). Linkage disequilibrium (LD) and association mapping studies were conducted to identify markers to tag the phenotypic traits. Decay of LD occurred over an average 9.3 cM for chromosomes 1-9 and 2.5 cM for chromosome 10. Marker/trait associations were generally identified based on general linear models (GLMs) that incorporated principal components from molecular information on relatedness factor. Seven markers (mTcCIR 8, 66, 126, 212; TcSNP368, 697, 1370) on chromosomes 1 and 9 were identified for number of filled seeds (NSEED). A single marker was found for black pod resistance (mTcCIR280) on chromosome 3, whereas six markers on chromosomes 4, 5, 6, 8, and 10 were detected for WBD (mTcCIR91, 183; TcSNP375, 720, 1230 and 1374). It is expected that this association mapping study in cacao would contribute to the knowledge of the genetic determinism of cocoa traits and that the markers identified herein would prove useful in marker assisted breeding of cacao.

The Effects of Different Extraction Methods on Antioxidant Properties, Chemical Composition, and Thermal Behavior of Black Seed (Nigella sativa L.) Oil.

PubMed

Mohammed, Nameer Khairullah; Abd Manap, Mohd Yazid; Tan, Chin Ping; Muhialdin, Belal J; Alhelli, Amaal M; Meor Hussin, Anis Shobirin

2016-01-01

The Nigella sativa L. popularly referred to as black seeds are widely used as a form of traditional nutrition and medicine. N. sativa seeds were used for the extraction of their oil by way of supercritical fluid extraction (SFE) and cold press (CP) to determine the physicochemical properties, antioxidant activity, and thermal behavior. The GC-MS results showed the primary constituents in the Nigella sativa oil (NSO) were Caryophyllene (17.47%) followed by thymoquinone (TQ) (11.80%), 1,4-Cyclohexadiene (7.17%), longifolene (3.5%), and carvacrol (1.82%). The concentration of TQ was found to be 6.63 mg/mL for oil extracted using SFE and 1.56 mg/mL for oil extracted by CP method. The antioxidant activity measured by DPPH and the IC50 was 1.58 mg/mL and 2.30 mg/mL for SFE oil and cold pressed oil, respectively. The ferric reducing/antioxidant power (FRAP) activity for SFE oil and CP oil was 538.67 mmol/100 mL and 329.00 mmol/100 mL, respectively. The total phenolic content (TPC) of SFE oil was 160.51 mg/100 mL and 94.40 mg/100 mL for CP oil presented as gallic acid equivalents (GAE). This research showed that a high level of natural antioxidants could be derived from NSO extracted by SFE.

The Effects of Different Extraction Methods on Antioxidant Properties, Chemical Composition, and Thermal Behavior of Black Seed (Nigella sativa L.) Oil

PubMed Central

Mohammed, Nameer Khairullah; Abd Manap, Mohd Yazid; Muhialdin, Belal J.; Alhelli, Amaal M.

2016-01-01

The Nigella sativa L. popularly referred to as black seeds are widely used as a form of traditional nutrition and medicine. N. sativa seeds were used for the extraction of their oil by way of supercritical fluid extraction (SFE) and cold press (CP) to determine the physicochemical properties, antioxidant activity, and thermal behavior. The GC-MS results showed the primary constituents in the Nigella sativa oil (NSO) were Caryophyllene (17.47%) followed by thymoquinone (TQ) (11.80%), 1,4-Cyclohexadiene (7.17%), longifolene (3.5%), and carvacrol (1.82%). The concentration of TQ was found to be 6.63 mg/mL for oil extracted using SFE and 1.56 mg/mL for oil extracted by CP method. The antioxidant activity measured by DPPH and the IC50 was 1.58 mg/mL and 2.30 mg/mL for SFE oil and cold pressed oil, respectively. The ferric reducing/antioxidant power (FRAP) activity for SFE oil and CP oil was 538.67 mmol/100 mL and 329.00 mmol/100 mL, respectively. The total phenolic content (TPC) of SFE oil was 160.51 mg/100 mL and 94.40 mg/100 mL for CP oil presented as gallic acid equivalents (GAE). This research showed that a high level of natural antioxidants could be derived from NSO extracted by SFE. PMID:27642353

Intermediate-Mass Black Holes in Globular Cluster Systems

NASA Astrophysics Data System (ADS)

Wrobel, J. M.; Miller-Jones, J. C. A.; Nyland, K. E.; Maccarone, T. J.

2018-01-01

Theory suggests that globular clusters (GCs) of stars can host intermediate-mass black holes (IMBHs) with masses of about 100 to 100,000 solar masses. We invoke a semi-empirical model to predict the mass of an IMBH that, if undergoing accretion in the long-lived hard X-ray state, is consistent with the synchrotron radio luminosity of a GC. We apply this model to extant images from the Karl G. Jansky Very Large Array (VLA) and to simulated images from the Next Generation Very Large Array (ngVLA). Guided by our VLA results for M81's system of 206 probable GCs at a distance of 3.6 Mpc, we consider using the ngVLA to study the hundreds of globular cluster systems out to a distance of 25 Mpc. With its sensitivity, spatial resolution, and field of view, we conclude that the ngVLA at 2cm will efficiently probe IMBH masses for tens of thousands of GCs. Finding IMBHs in GCs could validate a formation channel for seed BHs in the early universe, underpin gravitational wave predictions for space missions, and test scaling relations between stellar systems and the central BHs they host. The NRAO is a facility of the NSF, operated under cooperative agreement by AUI, Inc.

Versatile Gaussian probes for squeezing estimation

NASA Astrophysics Data System (ADS)

Rigovacca, Luca; Farace, Alessandro; Souza, Leonardo A. M.; De Pasquale, Antonella; Giovannetti, Vittorio; Adesso, Gerardo

2017-05-01

We consider an instance of "black-box" quantum metrology in the Gaussian framework, where we aim to estimate the amount of squeezing applied on an input probe, without previous knowledge on the phase of the applied squeezing. By taking the quantum Fisher information (QFI) as the figure of merit, we evaluate its average and variance with respect to this phase in order to identify probe states that yield good precision for many different squeezing directions. We first consider the case of single-mode Gaussian probes with the same energy, and find that pure squeezed states maximize the average quantum Fisher information (AvQFI) at the cost of a performance that oscillates strongly as the squeezing direction is changed. Although the variance can be brought to zero by correlating the probing system with a reference mode, the maximum AvQFI cannot be increased in the same way. A different scenario opens if one takes into account the effects of photon losses: coherent states represent the optimal single-mode choice when losses exceed a certain threshold and, moreover, correlated probes can now yield larger AvQFI values than all single-mode states, on top of having zero variance.

Radiation belt seed population and its association with the relativistic electron dynamics: A statistical study: Radiation Belt Seed Population

DOE PAGES

Tang, C. L.; Wang, Y. X.; Ni, B.; ...

2017-05-19

Using the Van Allen Probes data, we study the radiation belt seed population and it associated with the relativistic electron dynamics during 74 geomagnetic storm events. Based on the flux changes of 1 MeV electrons before and after the storm peak, these storm events are divided into two groups of “non-preconditioned” and “preconditioned”. The statistical study shows that the storm intensity is of significant importance for the distribution of the seed population (336 keV electrons) in the outer radiation belt. However, substorm intensity can also be important to the evolution of the seed population for some geomagnetic storm events. Formore » non-preconditioned storm events, the correlation between the peak fluxes and their L-shell locations of the seed population and relativistic electrons (592 keV, 1.0 MeV, 1.8 MeV, and 2.1 MeV) is consistent with the energy-dependent dynamic processes in the outer radiation belt. For preconditioned storm events, the correlation between the features of the seed population and relativistic electrons is not fully consistent with the energy-dependent processes. It is suggested that the good correlation between the radiation belt seed population and ≤1.0 MeV electrons contributes to the prediction of the evolution of ≤1.0 MeV electrons in the Earth’s outer radiation belt during periods of geomagnetic storms.« less

Radiation belt seed population and its association with the relativistic electron dynamics: A statistical study: Radiation Belt Seed Population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, C. L.; Wang, Y. X.; Ni, B.

Using the Van Allen Probes data, we study the radiation belt seed population and it associated with the relativistic electron dynamics during 74 geomagnetic storm events. Based on the flux changes of 1 MeV electrons before and after the storm peak, these storm events are divided into two groups of “non-preconditioned” and “preconditioned”. The statistical study shows that the storm intensity is of significant importance for the distribution of the seed population (336 keV electrons) in the outer radiation belt. However, substorm intensity can also be important to the evolution of the seed population for some geomagnetic storm events. Formore » non-preconditioned storm events, the correlation between the peak fluxes and their L-shell locations of the seed population and relativistic electrons (592 keV, 1.0 MeV, 1.8 MeV, and 2.1 MeV) is consistent with the energy-dependent dynamic processes in the outer radiation belt. For preconditioned storm events, the correlation between the features of the seed population and relativistic electrons is not fully consistent with the energy-dependent processes. It is suggested that the good correlation between the radiation belt seed population and ≤1.0 MeV electrons contributes to the prediction of the evolution of ≤1.0 MeV electrons in the Earth’s outer radiation belt during periods of geomagnetic storms.« less

Entropy in the interior of a higher-dimensional black hole

NASA Astrophysics Data System (ADS)

Yang, Jian-Zhi; Liu, Wen-Biao

2018-07-01

Recently Christodoulou and Rovelli brought out a sensible description for the black hole volume as the largest volume. Later the entropy related to this volume in a 4-dimensional Schwarzschild black hole was investigated, which showed that such entropy is proportional to the surface area of the black hole. We will probe into these issues in the context of higher-dimensional case. It is found that the proportion between this entropy and the Bekenstein-Hawking entropy will go down through dramatic change along with the increase of spacetime dimension.

BrachyView: Combining LDR seed positions with transrectal ultrasound imaging in a prostate gel phantom.

PubMed

Alnaghy, S; Cutajar, D L; Bucci, J A; Enari, K; Safavi-Naeini, M; Favoino, M; Tartaglia, M; Carriero, F; Jakubek, J; Pospisil, S; Lerch, M; Rosenfeld, A B; Petasecca, M

2017-02-01

BrachyView is a novel in-body imaging system which aims to provide LDR brachytherapy seeds position reconstruction within the prostate in real-time. The first prototype is presented in this study: the probe consists of a gamma camera featuring three single cone pinhole collimators embedded in a tungsten tube, above three, high resolution pixelated detectors (Timepix). The prostate was imaged with a TRUS system using a sagittal crystal with a 2.5mm slice thickness. Eleven needles containing a total of thirty 0.508U 125 I seeds were implanted under ultrasound guidance. A CT scan was used to localise the seed positions, as well as provide a reference when performing the image co-registration between the BrachyView coordinate system and the TRUS coordinate system. An in-house visualisation software interface was developed to provide a quantitative 3D reconstructed prostate based on the TRUS images and co-registered with the LDR seeds in situ. A rigid body image registration was performed between the BrachyView and TRUS systems, with the BrachyView and CT-derived source locations compared. The reconstructed seed positions determined by the BrachyView probe showed a maximum discrepancy of 1.78mm, with 75% of the seeds reconstructed within 1mm of their nominal location. An accurate co-registration between the BrachyView and TRUS coordinate system was established. The BrachyView system has shown its ability to reconstruct all implanted LDR seeds within a tissue equivalent prostate gel phantom, providing both anatomical and seed position information in a single interface. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Transient Astrophysics Probe

NASA Astrophysics Data System (ADS)

Camp, Jordan; Transient Astrophysics Probe Team

2018-01-01

The Transient Astrophysics Probe (TAP) is a wide-field multi-wavelength transient mission proposed for flight starting in the late 2020s. The mission instruments include unique “Lobster-eye” imaging soft X-ray optics that allow a ~1600 deg2 FoV; a high sensitivity, 1 deg2 FoV soft X-ray telescope; a 1 deg2 FoV Infrared telescope with bandpass 0.6-3 micron; and a set of 8 NaI gamma-ray detectors. TAP’s most exciting capability will be the observation of tens per year of X-ray and IR counterparts of GWs involving stellar mass black holes and neutron stars detected by LIGO/Virgo/KAGRA/LIGO-India, and possibly several per year X-ray counterparts of GWs from supermassive black holes, detected by LISA and Pulsar Timing Arrays. TAP will also discover hundreds of X-ray transients related to compact objects, including tidal disruption events, supernova shock breakouts, and Gamma-Ray Bursts from the epoch of reionization.

Local Operators in the Eternal Black Hole.

PubMed

Papadodimas, Kyriakos; Raju, Suvrat

2015-11-20

In the AdS/CFT correspondence, states obtained by Hamiltonian evolution of the thermofield doubled state are also dual to an eternal black-hole geometry, which is glued to the boundary with a time shift generated by a large diffeomorphism. We describe gauge-invariant relational observables that probe the black hole interior in these states and constrain their properties using effective field theory. By adapting recent versions of the information paradox we show that these observables are necessarily described by state-dependent bulk-boundary maps, which we construct explicitly.

PhylArray: phylogenetic probe design algorithm for microarray.

PubMed

Militon, Cécile; Rimour, Sébastien; Missaoui, Mohieddine; Biderre, Corinne; Barra, Vincent; Hill, David; Moné, Anne; Gagne, Geneviève; Meier, Harald; Peyretaillade, Eric; Peyret, Pierre

2007-10-01

Microbial diversity is still largely unknown in most environments, such as soils. In order to get access to this microbial 'black-box', the development of powerful tools such as microarrays are necessary. However, the reliability of this approach relies on probe efficiency, in particular sensitivity, specificity and explorative power, in order to obtain an image of the microbial communities that is close to reality. We propose a new probe design algorithm that is able to select microarray probes targeting SSU rRNA at any phylogenetic level. This original approach, implemented in a program called 'PhylArray', designs a combination of degenerate and non-degenerate probes for each target taxon. Comparative experimental evaluations indicate that probes designed with PhylArray yield a higher sensitivity and specificity than those designed by conventional approaches. Applying the combined PhyArray/GoArrays strategy helps to optimize the hybridization performance of short probes. Finally, hybridizations with environmental targets have shown that the use of the PhylArray strategy can draw attention to even previously unknown bacteria.

Massive Binary Black Holes in the Cosmic Landscape

NASA Astrophysics Data System (ADS)

Colpi, Monica; Dotti, Massimo

2011-02-01

Binary black holes occupy a special place in our quest for understanding the evolution of galaxies along cosmic history. If massive black holes grow at the center of (pre-)galactic structures that experience a sequence of merger episodes, then dual black holes form as inescapable outcome of galaxy assembly, and can in principle be detected as powerful dual quasars. But, if the black holes reach coalescence, during their inspiral inside the galaxy remnant, then they become the loudest sources of gravitational waves ever in the universe. The Laser Interferometer Space Antenna is being developed to reveal these waves that carry information on the mass and spin of these binary black holes out to very large look-back times. Nature seems to provide a pathway for the formation of these exotic binaries, and a number of key questions need to be addressed: How do massive black holes pair in a merger? Depending on the properties of the underlying galaxies, do black holes always form a close Keplerian binary? If a binary forms, does hardening proceed down to the domain controlled by gravitational wave back reaction? What is the role played by gas and/or stars in braking the black holes, and on which timescale does coalescence occur? Can the black holes accrete on flight and shine during their pathway to coalescence? After outlining key observational facts on dual/binary black holes, we review the progress made in tracing their dynamics in the habitat of a gas-rich merger down to the smallest scales ever probed with the help of powerful numerical simulations. N-Body/hydrodynamical codes have proven to be vital tools for studying their evolution, and progress in this field is expected to grow rapidly in the effort to describe, in full realism, the physics of stars and gas around the black holes, starting from the cosmological large scale of a merger. If detected in the new window provided by the upcoming gravitational wave experiments, binary black holes will provide a deep view

Probing pH difference between micellar solution and nanoscale water within common black film by fluorescent dye

NASA Astrophysics Data System (ADS)

Fu, Jingni; Zhang, Luning

2018-03-01

The protonation/deprotonation equilibrium of a fluorescent pH probe (carboxy-seminaphthorhodafluor-1, SNARF-1) within the nanoscale water layer confined in common black films (CBFs) has been studied. We find that SNARF-1 molecules feel a more acidic environment in CBFs than when they are in the bulk micellar solution, using the base/acid peak area ratio of the dye to indicate its microenvironment pH. Three surfactants are used to study the dependence of the pH drop versus charge: cationic (cetyltrimethylammonium bromide, CTAB), anionic (sodium dodecylsulphate, SDS) and nonionic (Triton X-100) species. The decrease of CBFs pH versus the pH of the micellar solution is the following: ΔpH ≈ 1.5 for CTAB (pH: 7.0-9.0), ΔpH ≈ 0.8 for SDS, and ΔpH ≈ 0.4 for Triton X-100. With the addition of electrolyte in CBFs, we observe large decrease the amplitude of the pH anomaly, thus suggesting an electrostatic origin of the pH change at nanoscale environment.

Validation of a quantitative NMR method for suspected counterfeit products exemplified on determination of benzethonium chloride in grapefruit seed extracts.

PubMed

Bekiroglu, Somer; Myrberg, Olle; Ostman, Kristina; Ek, Marianne; Arvidsson, Torbjörn; Rundlöf, Torgny; Hakkarainen, Birgit

2008-08-05

A 1H-nuclear magnetic resonance (NMR) spectroscopy method for quantitative determination of benzethonium chloride (BTC) as a constituent of grapefruit seed extract was developed. The method was validated, assessing its specificity, linearity, range, and precision, as well as accuracy, limit of quantification and robustness. The method includes quantification using an internal reference standard, 1,3,5-trimethoxybenzene, and regarded as simple, rapid, and easy to implement. A commercial grapefruit seed extract was studied and the experiments were performed on spectrometers operating at two different fields, 300 and 600 MHz for proton frequencies, the former with a broad band (BB) probe and the latter equipped with both a BB probe and a CryoProbe. The concentration average for the product sample was 78.0, 77.8 and 78.4 mg/ml using the 300 BB probe, the 600MHz BB probe and CryoProbe, respectively. The standard deviation and relative standard deviation (R.S.D., in parenthesis) for the average concentrations was 0.2 (0.3%), 0.3 (0.4%) and 0.3mg/ml (0.4%), respectively.

Gauge/Gravity correspondence and black hole attractors in various dimensions

NASA Astrophysics Data System (ADS)

Li, Wei

This thesis investigates several topics on Gauge/Gravity correspondence and black hole attractors in various dimensions. The first chapter contains a brief review and summary of main results. Chapters 2 and 3 aim at a microscopic description of black objects in five dimensions. Chapter 2 studies higher-derivative corrections for 5D black rings and spinning black holes. It shows that certain R 2 terms found in Calabi-Yau compactifications of M-theory yield macroscopic corrections to the entropies that match the microscopic corrections. Chapter 3 constructs probe brane configurations that preserve half of the enhanced near-horizon supersymmetry of 5D spinning black holes, whose near-horizon geometry is squashed AdS2 x S 3. There are supersymmetric zero-brane probes stabilized by orbital angular momentum on S3 and one-brane probes with momentum and winding around a U(1)L x U(1)R torus in S3. Chapter 4 constructs and analyzes generic single-centered and multi-centered black hole attractor solutions in various four-dimensional models which, after Kaluza-Klein reduction, admit a description in terms of 3D gravity coupled to a sigma model whose target space is symmetric coset space. The solutions correspond to certain nilpotent generators of the coset algebra. The non-BPS black hole attractors are found to be drastically different from their BPS counterparts. Chapter 5 examines three-dimensional topologically massive gravity with negative cosmological constant in asymptotically AdS 3 spacetimes. It proves that the theory is unitary and stable only at a special value of Chern-Simons coupling, where the theory becomes chiral. This suggests the existence of a stable, consistent quantum gravity theory at the chiral point which is dual to a holomorphic boundary CFT 2. Finally, Chapter 6 studies the two-dimensional N = 1 critical string theory with a linear dilaton background. It constructs time-dependent boundary state solutions that correspond to D0-branes falling toward the

Wilson loop's phase transition probed by non-local observable

NASA Astrophysics Data System (ADS)

Li, Hui-Ling; Feng, Zhong-Wen; Yang, Shu-Zheng; Zu, Xiao-Tao

2018-04-01

In order to give further insights into the holographic Van der Waals phase transition, it would be of great interest to investigate the behavior of Wilson loop across the holographic phase transition for a higher dimensional hairy black hole. We offer a possibility to proceed with a numerical calculation in order to discussion on the hairy black hole's phase transition, and show that Wilson loop can serve as a probe to detect a phase structure of the black hole. Furthermore, for a first order phase transition, we calculate numerically the Maxwell's equal area construction; and for a second order phase transition, we also study the critical exponent in order to characterize the Wilson loop's phase transition.

Selfing results in inbreeding depression of growth but not of gas exchange of surviving adult black spruce trees

Treesearch

Kurt Johnsen; John E. Major; Chris A. Maier

2003-01-01

Summary In most tree species, inbreeding greatly reduces seed production, seed viability, survival and growth. In a previous large-scale quantitative analysis of a black spruce (Picea mariana (Mill.) B.S.P.) diallel experiment, selfing had large deleterious effects on growth but no impact on stable carbon isotope discrimination (an...

Probing gravitational parity violation with gravitational waves from stellar-mass black hole binaries

NASA Astrophysics Data System (ADS)

Yagi, Kent; Yang, Huan

2018-05-01

The recent discovery of gravitational-wave events has offered us unique test beds of gravity in the strong and dynamical field regime. One possible modification to General Relativity is the gravitational parity violation that arises naturally from quantum gravity. Such parity violation gives rise to the so-called amplitude birefringence in gravitational waves, in which one of the circularly polarized modes is amplified while the other one is suppressed during their propagation. In this paper, we study how well one can measure gravitational parity violation via the amplitude birefringence effect of gravitational waves sourced by stellar-mass black hole binaries. We choose Chern-Simons gravity as an example and work within an effective field theory formalism to ensure that the approximate theory is well posed. We consider gravitational waves from both individual sources and stochastic gravitational-wave backgrounds. Regarding bounds from individual sources, we estimate such bounds using a Fisher analysis and carry out Monte Carlo simulations by randomly distributing sources over their sky location and binary orientation. We find that the bounds on the scalar field evolution in Chern-Simons gravity from the recently discovered gravitational-wave events are too weak to satisfy the weak Chern-Simons approximation, while aLIGO with its design sensitivity can place meaningful bounds. Regarding bounds from stochastic gravitational-wave backgrounds, we set the threshold signal-to-noise ratio for detection of the parity-violation mode as 5 and estimate projected bounds with future detectors assuming that signals are consistent with no parity violation. In an ideal situation in which all the source parameters and binary black hole merger-rate history are known a priori, we find that a network of two third-generation detectors is able to place bounds that are comparable to or slightly stronger than binary pulsar bounds. In a more realistic situation in which one does not have

Gene Silencing of BnTT10 Family Genes Causes Retarded Pigmentation and Lignin Reduction in the Seed Coat of Brassica napus

PubMed Central

Zhang, Kai; Lu, Kun; Qu, Cunmin; Liang, Ying; Wang, Rui; Chai, Yourong; Li, Jiana

2013-01-01

Yellow-seed (i.e., yellow seed coat) is one of the most important agronomic traits of Brassica plants, which is correlated with seed oil and meal qualities. Previous studies on the Brassicaceae, including Arabidopsis and Brassica species, proposed that the seed-color trait is correlative to flavonoid and lignin biosynthesis, at the molecular level. In Arabidopsis thaliana, the oxidative polymerization of flavonoid and biosynthesis of lignin has been demonstrated to be catalyzed by laccase 15, a functional enzyme encoded by the AtTT10 gene. In this study, eight Brassica TT10 genes (three from B. napus, three from B. rapa and two from B. oleracea) were isolated and their roles in flavonoid oxidation/polymerization and lignin biosynthesis were investigated. Based on our phylogenetic analysis, these genes could be divided into two groups with obvious structural and functional differentiation. Expression studies showed that Brassica TT10 genes are active in developing seeds, but with differential expression patterns in yellow- and black-seeded near-isogenic lines. For functional analyses, three black-seeded B. napus cultivars were chosen for transgenic studies. Transgenic B. napus plants expressing antisense TT10 constructs exhibited retarded pigmentation in the seed coat. Chemical composition analysis revealed increased levels of soluble proanthocyanidins, and decreased extractable lignin in the seed coats of these transgenic plants compared with that of the controls. These findings indicate a role for the Brassica TT10 genes in proanthocyanidin polymerization and lignin biosynthesis, as well as seed coat pigmentation in B. napus. PMID:23613820

Growth problems of stellar black holes in early galaxies

NASA Astrophysics Data System (ADS)

Orofino, M. C.; Ferrara, A.; Gallerani, S.

2018-06-01

The nature of the seeds of the observed high-z super-massive black holes (SMBH) is unknown. Although different options have been proposed, involving e.g. intermediate mass direct collapse black holes, BH remnants of massive stars remain the most natural explanation. To identify the most favorable conditions (if any) for their rapid growth, we study the accretion rate of a M• = 100M⊙ BH formed in a typical z = 10 galaxy under different conditions (e.g. galaxy structure, BH initial position and velocity). We model the galaxy baryonic content and follow the BH orbit and accretion history for 300 Myr (the time span in 10 > z > 7), assuming the radiation-regulated accretion model by Park & Ricotti (2013). We find that, within the limits of our model, BH seeds cannot grow by more than 30%, suggesting that accretion on light-seed models are inadequate to explain high-z SMBH. We also compute the X-ray emission from such accreting stellar BH population in the [0.5 - 8] keV band and find it comparable to the one produced by high-mass X-ray binaries. This study suggests that early BHs, by X-ray pre-heating of the intergalactic medium at cosmic dawn, might leave a specific signature on the HI 21 cm line power spectrum potentially detectable with SKA.

Practical strategies of black walnut genetic improvement—an update

Treesearch

George Rink; J.W. Van Sambeek; Phil O' Connor; Mark Coggeshall

2017-01-01

The ultimate goal of any tree improvement program is the large-scale production and distribution of genetically improved seedlings. In black walnut, projections based on earlier research indicate that genetically improved seedlings could provide growth improvement of between 15 to 25 percent by using seed or seedlings of the proper geographic origin (Bey 1980; Clausen...

Black walnut response to subsoiling, irrigation, and vegetation management on a site with a shallow fragipan

Treesearch

F. D. McBride; J. W. Van Sambeek

1995-01-01

Vegetation management with glyphosate and simazine proved to be more effective than preplant subsoiling or irrigation for achieving acceptable walnut biomass growth on an upland old field site (SI = 70 for white oak). In 1980, we direct seeded germinating black walnut seed on an upland, slightly eroded, old field ridge with a 45 to 60 cm deep fragipan. We tested all...

Association mapping of fruit, seed and disease resistance traits in Theobroma cacao L

USDA-ARS?s Scientific Manuscript database

An association mapping approach was employed to find markers for color, size, girth and mass of fruits; seed number and butterfat content; and resistance to black pod and witches’ broom diseases in cacao (Theobroma cacao L.). Ninety-five microsatellites (SSRs) and 775 single nucleotide polymorphisms...

The Vigna unguiculata Gene Expression Atlas (VuGEA) from de novo assembly and quantification of RNA-seq data provides insights into seed maturation mechanisms.

PubMed

Yao, Shaolun; Jiang, Chuan; Huang, Ziyue; Torres-Jerez, Ivone; Chang, Junil; Zhang, Heng; Udvardi, Michael; Liu, Renyi; Verdier, Jerome

2016-10-01

Legume research and cultivar development are important for sustainable food production, especially of high-protein seed. Thanks to the development of deep-sequencing technologies, crop species have been taken to the front line, even without completion of their genome sequences. Black-eyed pea (Vigna unguiculata) is a legume species widely grown in semi-arid regions, which has high potential to provide stable seed protein production in a broad range of environments, including drought conditions. The black-eyed pea reference genotype has been used to generate a gene expression atlas of the major plant tissues (i.e. leaf, root, stem, flower, pod and seed), with a developmental time series for pods and seeds. From these various organs, 27 cDNA libraries were generated and sequenced, resulting in more than one billion reads. Following filtering, these reads were de novo assembled into 36 529 transcript sequences that were annotated and quantified across the different tissues. A set of 24 866 unique transcript sequences, called Unigenes, was identified. All the information related to transcript identification, annotation and quantification were stored into a gene expression atlas webserver (http://vugea.noble.org), providing a user-friendly interface and necessary tools to analyse transcript expression in black-eyed pea organs and to compare data with other legume species. Using this gene expression atlas, we inferred details of molecular processes that are active during seed development, and identified key putative regulators of seed maturation. Additionally, we found evidence for conservation of regulatory mechanisms involving miRNA in plant tissues subjected to drought and seeds undergoing desiccation. © 2016 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.

Hamiltonian formalism for Perturbed Black Hole Spacetimes

NASA Astrophysics Data System (ADS)

Mihaylov, Deyan; Gair, Jonathan

2017-01-01

Present and future gravitational wave observations provide a new mechanism to probe the predictions of general relativity. Observations of extreme mass ratio inspirals with millihertz gravitational wave detectors such as LISA will provide exquisite constraints on the spacetime structure outside astrophysical black holes, enabling tests of the no-hair property that all general relativistic black holes are described by the Kerr metric. Previous work to understand what constraints LISA observations will be able to place has focussed on specific alternative theories of gravity, or generic deviations that preserve geodesic separability. We describe an alternative approach to this problem--a technique that employs canonical perturbations of the Hamiltonian function describing motion in the Kerr metric. We derive this new approach and demonstrate its application to the cases of a slowly rotating Kerr black hole which is viewed as a perturbation of a Schwarzschild black hole, of coupled perturbations of black holes in the second-order Chern-Simons modified gravity theory, and several more indicative scenarios. Deyan Mihaylov is funded by STFC.

Herbal infusions of black seed and wheat germ oil: Their chemical profiles, in vitro bio-investigations and effective formulations as Phyto-Nanoemulsions.

PubMed

Gumus, Z Pinar; Guler, Emine; Demir, Bilal; Barlas, F Baris; Yavuz, Murat; Colpankan, Dilara; Senisik, A Murat; Teksoz, Serap; Unak, Perihan; Coskunol, Hakan; Timur, Suna

2015-09-01

The reported studies related to black seed oil (BSO) and wheat germ oil (WGO) have illustrated that they have a wide range of biological activities. Therefore, enhancing the amount of bio-active compounds that caused higher cell based anti-oxidative effect as well as cell proliferation, etc. in seed oils, infusion of crude plant material has been gained importance as a traditional technique. Herein, we accomplished the infusion of Calendula flowers that also contains many phyto-constituents into BSO and WGO. After the infusion of oils, the change of phytochemical amount was investigated and evaluated according to the oils by chromatography, radical scavenging activity. Subsequently, for investigating the biological impact upon live cells, cytotoxicity, cell-based antioxidant capacity, wound healing and radioprotective activity were tested with monkey kidney fibroblast like cells (Vero) and HaCaT keratinocytes. In vitro cell based experiments (wound healing and radioprotective activity) confirmed that Calendula infused BSO and WGO have greater bio-activity when compared to those plain forms. The herbal oils prepared with an effective extraction technique were incorporated into nanoemulsion systems which will be then called as 'Phyto-Nanoemulsion'. After herbal oil biomolecules were encapsulated into nanoemulsion based delivery systems, the designed formulations were investigated in terms of biological activities. In conclusion, these preparations could be a good candidate as a part of dermal cosmetic products or food supplements which have the therapeutic efficiency, especially after radio- or chemotherapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Primordial Black Holes as Generators of Cosmic Structures

NASA Astrophysics Data System (ADS)

Carr, Bernard; Silk, Joseph

2018-05-01

Primordial black holes (PBHs) could provide the dark matter in various mass windows below 102M⊙ and those of 30M⊙ might explain the LIGO events. PBHs much larger than this might have important consequences even if they provide only a small fraction of the dark matter. In particular, they could generate cosmological structure either individually through the `seed' effect or collectively through the `Poisson' effect, thereby alleviating some problems associated with the standard CDM scenario. If the PBHs all have a similar mass and make a small contribution to the dark matter, then the seed effect dominates on small scales, in which case PBHs could generate the supermassive black holes in galactic nuclei or even galaxies themselves. If they have a similar mass and provide the dark matter, the Poisson effect dominates on all scales and the first bound clouds would form earlier than in the usual scenario, with interesting observational consequences. If the PBHs have an extended mass spectrum, which is more likely, they could fulfill all three roles - providing the dark matter, binding the first bound clouds and generating galaxies. In this case, the galactic mass function naturally has the observed form, with the galaxy mass being simply related to the black hole mass. The stochastic gravitational wave background from the PBHs in this scenario would extend continuously from the LIGO frequency to the LISA frequency, offering a potential goal for future surveys.

Ergoregions in magnetized black hole spacetimes

NASA Astrophysics Data System (ADS)

Gibbons, G. W.; Mujtaba, A. H.; Pope, C. N.

2013-06-01

The spacetimes obtained by Ernst’s procedure for appending an external magnetic field B to a seed Kerr-Newman black hole are commonly believed to be asymptotic to the static Melvin metric. We show that this is not in general true. Unless the electric charge of the black hole satisfies Q= jB(1+{\\textstyle {\\frac{\\scriptstyle 1}{\\scriptstyle 4} } } j^2 B^4), where j is the angular momentum of the original seed solution, an ergoregion extends all the way from the black hole horizon to infinity. We find that if the condition on the electric charge is satisfied then the metric is asymptotic to the static Melvin metric, and the electromagnetic field carries not only magnetic, but also electric, flux along the axis. We give a self-contained account of the solution-generating procedure, including explicit formulae for the metric and the vector potential. In the case when Q= jB(1+{\\textstyle {\\frac{\\scriptstyle 1}{\\scriptstyle 4} } } j^2 B^4), we show that there is an arbitrariness in the choice of asymptotically timelike Killing field K_\\Omega = {\\partial }/{\\partial }t+ \\Omega \\, {\\partial }/{\\partial }\\phi, because there is no canonical choice of Ω. For one choice, Ω = Ωs, the metric is asymptotically static, and there is an ergoregion confined to the neighbourhood of the horizon. On the other hand, by choosing Ω = ΩH, so that K_{\\Omega _H} is co-rotating with the horizon, then for sufficiently large B numerical studies indicate there is no ergoregion at all. For smaller values, in a range B- < B < B+, there is a toroidal ergoregion outside and disjoint from the horizon. If B ⩽ B- this ergoregion expands all the way to infinity in a cylindrical region near to the rotation axis. For black holes whose size is small compared to the Melvin radius 2/B, and neglecting back-reaction of the electromagnetic field, we recover Wald’s result that it is energetically favourable for the hole to acquire a charge 2jB.

Evaluation of topical black seed oil in the treatment of allergic rhinitis.

PubMed

Alsamarai, Abdulghani Mohamed; Abdulsatar, Mohamed; Ahmed Alobaidi, Amina Hamed

2014-03-01

Allergic rhinitis (AR) is the most common manifestation of atopic reaction to inhaled allergens. It is a chronic inflammatory disease which may first appear at any age, but the onset is usually during childhood or adolescence. Up to date there is no curative treatment for this disorder and most of the drugs that were used for treatment only can induce symptomatic relief and some of them have side effect and can cause withdrawal symptoms. To evaluate the therapeutic efficacy of the Nigella sativa (NS) extract as treatment approach for allergic rhinitis. A total of 68 patients with AR were included in the study, of them 19 patients were with mild symptoms, 28 patients were with moderate symptoms and 21 patients were with severe symptoms. Each group was subdivided into active and control subgroups. To prove that the patient's symptoms were allergic in nature, skin test was performed for all patients. Any individual with negative skin test was excluded. The individuals in the active group received N. sativa oil and the control group individuals received ordinary food oil in the form of nasal drops for 6 weeks. After the 6 weeks treatment course, 100% of the patients in the mild active group became symptoms free; while in moderate active group 68.7% became symptoms free and 25% were improved; while in severe active group 58.3% became symptoms free and 25% were improved. In addition, 92.1% of total patients in the active group demonstrated improvement in their symptoms or were symptoms free, while the corresponding value was 30.1% in the control group (P=0.000). At the end of 6 weeks of treatment with topical use, the improvement in tolerability of allergen exposure in active group became 55.2% which was significant (P=0.006) as compared with control group which was accounted for 20% at the same time. Topical application of black seed oil was effective in the treatment of allergic rhinitis, with minimal side effects.

The physics of black hole x ray novae

NASA Technical Reports Server (NTRS)

Wheeler, J. C.; Kim, S.-W.; Moscoso, M. D.; Mineshige, S.

1994-01-01

X-ray transients that are established or plausible black hole candidates have been discovered at a rate of about one per year in the galaxy for the last five years. There are now well over a dozen black hole candidates, most being in the category of X-ray novae with low-mass companions. There may be hundreds of such transient systems in the galaxy yet to be discovered. Classic black hole candidates like Cygnus X-1 with massive companions are in the minority, and their census in the galaxy and magellanic clouds is likely to be complete. The black hole X-ray novae (BHXN) do not represent only the most common environment in which to discover black holes. Their time dependence gives a major new probe with which to study the physics of accretion into black holes. The BHXN show both a soft X-ray flux from an optically thick disk and a hard power law tail that is reminiscent of AGN spectra. The result may be new insight into the classical systems like Cyg X-1 and LMC X-1 that show similar power law tails, but also to accretion into supermassive black holes and AGN.

Solving puzzles of GW150914 by primordial black holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blinnikov, S.; Dolgov, A.; Porayko, N.K.

The black hole binary properties inferred from the LIGO gravitational wave signal GW150914 posed several serious problems. The high masses and low effective spin of black hole binary can be explained if they are primordial (PBH) rather than the products of the stellar binary evolution. Such PBH properties are postulated ad hoc but not derived from fundamental theory. We show that the necessary features of PBHs naturally follow from the slightly modified Affleck-Dine (AD) mechanism of baryogenesis. The log-normal distribution of PBHs, predicted within the AD paradigm, is adjusted to provide an abundant population of low-spin stellar mass black holes.more » The same distribution gives a sufficient number of quickly growing seeds of supermassive black holes observed at high redshifts and may comprise an appreciable fraction of Dark Matter which does not contradict any existing observational limits. Testable predictions of this scenario are discussed.« less

Black holes in the early Universe.

PubMed

Volonteri, Marta; Bellovary, Jillian

2012-12-01

The existence of massive black holes (MBHs) was postulated in the 1960s, when the first quasars were discovered. In the late 1990s their reality was proven beyond doubt in the Milky way and a handful nearby galaxies. Since then, enormous theoretical and observational efforts have been made to understand the astrophysics of MBHs. We have discovered that some of the most massive black holes known, weighing billions of solar masses, powered luminous quasars within the first billion years of the Universe. The first MBHs must therefore have formed around the time the first stars and galaxies formed. Dynamical evidence also indicates that black holes with masses of millions to billions of solar masses ordinarily dwell in the centers of today's galaxies. MBHs populate galaxy centers today, and shone as quasars in the past; the quiescent black holes that we detect now in nearby bulges are the dormant remnants of this fiery past. In this review we report on basic, but critical, questions regarding the cosmological significance of MBHs. What physical mechanisms led to the formation of the first MBHs? How massive were the initial MBH seeds? When and where did they form? How is the growth of black holes linked to that of their host galaxy? The answers to most of these questions are works in progress, in the spirit of these reports on progress in physics.

Effect of seed position and media on germination of black walnut and northern red oak: implications for nursery production and direct seeding

Treesearch

Anthony S. Davis; Barrett C. Wilson; Douglass F. Jacobs

2004-01-01

Germination of black walnut (Juglans nigra L.) and northern red oak (Quercus rubra L.) prior to sowing into containers or bareroot nursery beds can help maintain desired crop density and reduce nursery costs. Recommended techniques for germination of black walnut are labor intensive and require that walnuts be completely covered...

Mating parameter estimates of black walnut based on natural and artificial populations

Treesearch

George Rink; Guoqiang Zhang; Zuo Jinghua; Fan H. Kung

1995-01-01

Horizontal starch gel electrophoresis was performed on six polymorphic loci in black walnut (Juglans nigra L.) embryos from open-pollinated nut collections made in 1987 in a Missouri half-sib progeny test, and Indiana seed orchard and a natural population in southern Illinois.

Black doctors and discrimination under South Africa's apartheid regime.

PubMed

Digby, Anne

2013-04-01

This article discusses an under-researched group and provides an analytical overview of the comparative experiences of African, Indian and Coloured doctors at South African universities during the apartheid era. It probes diversity of experience in training and practice as well as gendered differentiation amongst black students before going on to discuss the careers and political activism of black doctors as well as the impact of recent transformational change on their position. It briefly assesses how singular this South African experience was.

Seed dispersal ability of the invasive perennial vines Vincetoxicum nigrum and Vincetoxicum rossicum

USDA-ARS?s Scientific Manuscript database

Black swallowwort and pale swallowwort are perennial vines of European origin that invade natural areas and perennial cropping systems in the northeastern United States and southeastern Canada. Both species reproduce via wind-dispersed seeds in the form of achenes with a coma, but little is known a...

Impact of membrane-induced particle immobilization on seeded growth monitored by in situ liquid scanning transmission electron microscopy

DOE PAGES

Weiner, Rebecca G.; Chen, Dennis P.; Unocic, Raymond R.; ...

2016-04-01

In situ liquid cell scanning transmission electron microscopy probes seeded growth in real time. The growth of Pd on Au nanocubes is monitored as a model system to compare growth within a liquid cell and traditional colloidal synthesis. Furthermore, different growth patterns are observed due to seed immobilization and the highly reducing environment within the liquid cell.

Black Holes Masses in Seyfert Galaxies

NASA Technical Reports Server (NTRS)

Macchetto, F. D.

2004-01-01

There is increasing evidence for the existence of supermassive black holes at the centers of all galaxies, and much work is being devoted to understand the process that lead to their formation, the duty cycle for the active phase of these black holes and the relevant fueling mechanisms. Seyfert galaxies determined by HST high spatial resolution observations of the kinematics of the central regions. The study of the gas kinematics provides a unique tool to probe the gravitational potential of the nuclear regions of Seyfert galaxies down to a limit radius of a few parsecs. This is particularly important to detect and measure the mass associated with any central massive black hole. We have obtained high spatial resolution spectra of a number of Seyfert galaxies, with the STIS G430M and G750M gratings, and we have been able to separate the emission line components associated with different velocity systems. We have derived two-dimensional velocity fields and determined the mass of the central black hole with good precision for each of the galaxies.

Unpacking the black box of improvement

PubMed Central

Ramaswamy, Rohit; Reed, Julie; Livesley, Nigel; Boguslavsky, Victor; Garcia-Elorrio, Ezequiel; Sax, Sylvia; Houleymata, Diarra; Kimble, Leighann; Parry, Gareth

2018-01-01

Abstract During the Salzburg Global Seminar Session 565—‘Better Health Care: How do we learn about improvement?’, participants discussed the need to unpack the ‘black box’ of improvement. The ‘black box’ refers to the fact that when quality improvement interventions are described or evaluated, there is a tendency to assume a simple, linear path between the intervention and the outcomes it yields. It is also assumed that it is enough to evaluate the results without understanding the process of by which the improvement took place. However, quality improvement interventions are complex, nonlinear and evolve in response to local settings. To accurately assess the effectiveness of quality improvement and disseminate the learning, there must be a greater understanding of the complexity of quality improvement work. To remain consistent with the language used in Salzburg, we refer to this as ‘unpacking the black box’ of improvement. To illustrate the complexity of improvement, this article introduces four quality improvement case studies. In unpacking the black box, we present and demonstrate how Cynefin framework from complexity theory can be used to categorize and evaluate quality improvement interventions. Many quality improvement projects are implemented in complex contexts, necessitating an approach defined as ‘probe-sense-respond’. In this approach, teams experiment, learn and adapt their changes to their local setting. Quality improvement professionals intuitively use the probe-sense-respond approach in their work but document and evaluate their projects using language for ‘simple’ or ‘complicated’ contexts, rather than the ‘complex’ contexts in which they work. As a result, evaluations tend to ask ‘How can we attribute outcomes to the intervention?’, rather than ‘What were the adaptations that took place?’. By unpacking the black box of improvement, improvers can more accurately document and describe their interventions

Zinc and selenium accumulation and their effect on iron bioavailability in common bean seeds.

PubMed

de Figueiredo, Marislaine A; Boldrin, Paulo F; Hart, Jonathan J; de Andrade, Messias J B; Guilherme, Luiz R G; Glahn, Raymond P; Li, Li

2017-02-01

Common beans (Phaseolus vulgaris) are the most important legume crops. They represent a major source of micronutrients and a target for essential trace mineral enhancement (i.e. biofortification). To investigate mineral accumulation during seed maturation and to examine whether it is possible to biofortify seeds with multi-micronutrients without affecting mineral bioavailability, three common bean cultivars were treated independently with zinc (Zn) and selenium (Se), the two critical micronutrients that can be effectively enhanced via fertilization. The seed mineral concentrations during seed maturation and the seed Fe bioavailability were analyzed. Common bean seeds were found to respond positively to Zn and Se treatments in accumulating these micronutrients. While the seed pods showed a decrease in Zn and Se along with Fe content during pod development, the seeds maintained relatively constant mineral concentrations during seed maturation. Selenium treatment had minimal effect on the seed accumulation of phytic acid and polyphenols, the compounds affecting Fe bioavailability. Zinc treatment reduced phytic acid level, but did not dramatically affect the concentrations of total polyphenols. Iron bioavailability was found not to be greatly affected in seeds biofortified with Se and Zn. In contrast, the inhibitory polyphenol compounds in the black bean profoundly reduced Fe bioavailability. These results provide valuable information for Se and Zn enhancement in common bean seeds and suggest the possibility to biofortify with these essential nutrients without greatly affecting mineral bioavailability to increase the food quality of common bean seeds. Published by Elsevier Masson SAS.

Intermediate-mass Black Holes and Dark Matter at the Galactic Center

NASA Astrophysics Data System (ADS)

Lacroix, Thomas; Silk, Joseph

2018-01-01

Could there be a large population of intermediate-mass black holes (IMBHs) formed in the early universe? Whether primordial or formed in Population III, these are likely to be very subdominant compared to the dark matter density, but could seed early dwarf galaxy/globular cluster and supermassive black hole formation. Via survival of dark matter density spikes, we show here that a centrally concentrated relic population of IMBHs, along with ambient dark matter, could account for the Fermi gamma-ray “excess” in the Galactic center because of dark matter particle annihilations.

A multi-sensor study of the impact of ground-based glaciogenic seeding on clouds and precipitation over mountains in Wyoming. Part II: Seeding impact analysis

NASA Astrophysics Data System (ADS)

Pokharel, Binod; Geerts, Bart; Jing, Xiaoqin; Friedrich, Katja; Ikeda, Kyoko; Rasmussen, Roy

2017-01-01

The AgI Seeding Cloud Impact Investigation (ASCII) campaign, conducted in early 2012 and 2013 over two mountain ranges in southern Wyoming, was designed to examine the impact of ground-based glaciogenic seeding on snow growth in winter orographic clouds. Part I of this study (Pokharel and Geerts, 2016) describes the project design, instrumentation, as well as the ambient atmospheric conditions and macrophysical and microphysical properties of the clouds sampled in ASCII. This paper (Part II) explores how the silver iodide (AgI) seeding affects snow growth in these orographic clouds in up to 27 intensive operation periods (IOPs), depending on the instrument used. In most cases, 2 h without seeding (NOSEED) were followed by 2 h of seeding (SEED). In situ data at flight level (2D-probes) indicate higher concentrations of small snow particles during SEED in convective clouds. The double difference of radar reflectivity Z (SEED - NOSEED in the target region, compared to the same trend in the control region) indicates an increase in Z for the composite of ASCII cases, over either mountain range, and for any of the three radar systems (WCR, MRR, and DOW), each with their own control and target regions, and for an array of snow gauges. But this double difference varies significantly from case to case, which is attributed to uncertainties related to sampling representativeness and to differences in natural trends between control and target regions. We conclude that a sample much larger than ASCII's sample is needed for clear observational evidence regarding the sensitivity of seeding efficacy to atmospheric and cloud conditions.

Invited Article: Coherent imaging using seeded free-electron laser pulses with variable polarization: First results and research opportunities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capotondi, F.; Pedersoli, E.; Mahne, N.

2013-05-15

FERMI-Elettra, the first vacuum ultraviolet and soft X-ray free-electron laser (FEL) using by default a 'seeded' scheme, became operational in 2011 and has been opened to users since December 2012. The parameters of the seeded FERMI FEL pulses and, in particular, the superior control of emitted radiation in terms of spectral purity and stability meet the stringent requirements for single-shot and resonant coherent diffraction imaging (CDI) experiments. The advantages of the intense seeded FERMI pulses with variable polarization have been demonstrated with the first experiments performed using the multipurpose experimental station operated at the diffraction and projection imaging (DiProI) beamline.more » The results reported here were obtained with fixed non-periodic targets during the commissioning period in 2012 using 20-32 nm wavelength range. They demonstrate that the performance of the FERMI FEL source and the experimental station meets the requirements of CDI, holography, and resonant magnetic scattering in both multi- and single-shot modes. Moreover, we present the first magnetic scattering experiments employing the fully circularly polarized FERMI pulses. The ongoing developments aim at pushing the lateral resolution by using shorter wavelengths provided by double-stage cascaded FERMI FEL-2 and probing ultrafast dynamic processes using different pump-probe schemes, including jitter-free seed laser pump or FEL-pump/FEL-probe with two color FEL pulses generated by the same electron bunch.« less

How big can a black hole grow?

NASA Astrophysics Data System (ADS)

King, Andrew

2016-02-01

I show that there is a physical limit to the mass of a black hole, above which it cannot grow through luminous accretion of gas, and so cannot appear as a quasar or active galactic nucleus (AGN). The limit is Mmax ≃ 5 × 1010 M⊙ for typical parameters, but can reach Mmax ≃ 2.7 × 1011 M⊙ in extreme cases (e.g. maximal prograde spin). The largest black hole masses so far found are close to but below the limit. The Eddington luminosity ≃6.5 × 1048 erg s-1 corresponding to Mmax is remarkably close to the largest AGN bolometric luminosity so far observed. The mass and luminosity limits both rely on a reasonable but currently untestable hypothesis about AGN disc formation, so future observations of extreme supermassive black hole masses can therefore probe fundamental disc physics. Black holes can in principle grow their masses above Mmax by non-luminous means such as mergers with other holes, but cannot become luminous accretors again. They might nevertheless be detectable in other ways, for example through gravitational lensing. I show further that black holes with masses ˜Mmax can probably grow above the values specified by the black-hole-host-galaxy scaling relations, in agreement with observation.

On the effect of Lyman α trapping during the initial collapse of massive black hole seeds

NASA Astrophysics Data System (ADS)

Ge, Qi; Wise, John H.

2017-12-01

One viable seeding mechanism for supermassive black holes is the direct gaseous collapse route in pre-galactic dark matter haloes, producing objects on the order of 104-106 M⊙. These events occur when the gas is prevented from cooling below 104 K that requires a metal-free and relatively H2-free medium. The initial collapse cools through atomic hydrogen transitions, but the gas becomes optically thick to the cooling radiation at high densities. We explore the effects of Lyman α trapping in such a collapsing system with a suite of Monte Carlo radiation transport calculations in uniform density and isotropic cases that are based from a cosmological simulation. Our method includes both non-coherent scattering and two-photon line cooling. We find that Lyman α radiation is marginally trapped in the parsec-scale gravitationally unstable central cloud, allowing the temperature to increase to 50 000 K at a number density of 3 × 104 cm-3 and increasing the Jeans mass by a factor of 5. The effective equation of state changes from isothermal at low densities to have an adiabatic index of 4/3 around the temperature maximum and then slowly retreats back to isothermal at higher densities. Our results suggest that Lyman α trapping delays the initial collapse by raising the Jeans mass. Afterward the high-density core cools back to 104 K that is surrounded by a warm envelope whose inward pressure may alter the fragmentation scales at high densities.

A graphic technique for identifying superior seed sources for central hardwoods

Treesearch

Fan H. Kung; George Rink

1993-01-01

To maximize forest production, foresters need to plant the best genotypes provided by forest geneticists. Where should the forest geneticist search for the best seed sources? How far can one go south, or north to find them? The answer may rely on the species and the location of the test plantation. For example, when black walnut trees were tested in Illinois, Indiana,...

Full-Tree SKidding Black Spruce: Another Way to Favor Reproduction

Treesearch

William F. Johnston

1975-01-01

An alternative to burning is needed for clearcut peatlands where only slash disposal is required to rapidly reproduce black spruce. A 2-year trial in north-central Minnesota indicates that reproduction will be rapid after full-tree skidding on nonbrushy sites taht have well-distribted sphagnum seedbeds and ample natural seeding. Broadcast burning is still recommended...

Antioxidants and bioactivities of free, esterified and insoluble-bound phenolics from berry seed meals.

PubMed

Ayoub, Maha; de Camargo, Adriano Costa; Shahidi, Fereidoon

2016-04-15

Phenolic compounds present in the free, soluble ester and insoluble-bound forms of blackberry, black raspberry and blueberry were identified and quantified using high-performance liquid chromatography-diode array detection-electrospray ionisation multistage mass spectrometry. The total phenolics, scavenging activity against hydroxyl and peroxyl radicals, the reducing power and chelating capacity were, in general, in the decreasing order of blackberry>black raspberry>blueberry. Amongst fractions, the order was insoluble-bound>esterified>free. These trends were the same as those found against copper-induced LDL-cholesterol oxidation and supercoiled plasmid DNA strand breakage inhibition induced by both peroxyl and hydroxyl radicals. Extracts were found to contain various levels of phenolic compounds that were specific to each berry seed meal type. Berry seed meals should be considered as a good source of phenolics with potential health benefits. Their full exploitation may be helpful for the food industry and consumers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Horndeski theories confront the Gravity Probe B experiment

NASA Astrophysics Data System (ADS)

Mukherjee, Sajal; Chakraborty, Sumanta

2018-06-01

In this work we have investigated various properties of a spinning gyroscope in the context of Horndeski theories. In particular, we have focused on two specific situations—(a) when the gyroscope follows a geodesic trajectory and (b) when it is endowed with an acceleration. In both these cases, besides developing the basic formalism, we have also applied the same to understand the motion of a spinning gyroscope in various static and spherically symmetric spacetimes pertaining to Horndeski theories. Starting with the Schwarzschild de Sitter spacetime as a warm up exercise, we have presented our results for two charged Galileon black holes as well as for a black hole in scalar coupled Einstein-Gauss-Bonnet gravity. In all these cases we have shown that the spinning gyroscope can be used to distinguish black holes from naked singularities. Moreover, using the numerical estimation of the geodetic precession from the Gravity Probe B experiment, we have constrained the gauge/scalar charge of the black holes in these Horndeski theories. Implications are also discussed.

Gravitational Waves From The Hierarchical Buildup Of Intermediate Mass Black Holes

NASA Astrophysics Data System (ADS)

Micic, Miroslav; Sigurdsson, S.; Holley-Bockelmann, K.; Abel, T.

2006-12-01

Using high-resolution N-body simulations in LambdaCDM universe, we have constructed dark matter structure's merger tree that traces evolution of dark matter halos, their subhalos and massive black holes (MBH) formed from Population III stars. Such early black holes, formed at redshifts z > 10, could be the seed black holes for the many SMBH found in galaxies in the local universe. Mergers of MBH may be a prime signal for long wavelength gravitaional wave detectors. We study trajectories of MBH, formation of MBH binaries and calculate gravitational strain amplitude as a function of redshift. We also explore the implications of kick velocities conjectured by some formation models. The central concentration of early black holes in present day galaxies is reduced if they are born even with moderate kicks of tens km/s. The modest kicks allow the black holes to leave their parent halo, which consequently leads to dynamical friction being less effective on the lower mass black holes as compared to those still embedded in their parent halos. Therefore, merger rates may be reduced by more then an order of magnitude. We quantify the role of kicks on black hole merger rates. Our results also apply to black holes ejected by the gravitational slingshot mechanism.

Biocontrol Potential of Streptomyces hydrogenans Strain DH16 toward Alternaria brassicicola to Control Damping Off and Black Leaf Spot of Raphanus sativus

PubMed Central

Manhas, Rajesh K.; Kaur, Talwinder

2016-01-01

Biocontrol agents and their bioactive metabolites provide one of the best alternatives to decrease the use of chemical pesticides. In light of this, the present investigation reports the biocontrol potential of Streptomyces hydrogenans DH16 and its metabolites towards Alternaria brassicicola, causal agent of black leaf spot and damping off of seedlings of crucifers. In vitro antibiosis of strain against pathogen revealed complete suppression of mycelial growth of pathogen, grown in potato dextrose broth supplemented with culture supernatant (20% v/v) of S. hydrogenans DH16. Microscopic examination of the fungal growth showed severe morphological abnormalities in the mycelium caused by antifungal metabolites. In vivo studies showed the efficacy of streptomycete cells and culture supernatant as seed dressings to control damping off of Raphanus sativus seedlings. Treatment of pathogen infested seeds with culture supernatant (10%) and streptomycete cells significantly improved seed germination (75–80%) and vigor index (1167–1538). Furthermore, potential of cells and culture supernatant as foliar treatment to control black leaf spot was also evaluated. Clearly visible symptoms of disease were observed in the control plants with 66.81% disease incidence and retarded growth of root system. However, disease incidence reduced to 6.78 and 1.47% in plants treated with antagonist and its metabolites, respectively. Additionally, treatment of seeds and plants with streptomycete stimulated various growth traits of plants over uninoculated control plants in the absence of pathogen challenge. These results indicate that S. hydrogenans and its culture metabolites can be developed as biofungicides as seed dressings to control seed borne pathogens, and as sprays to control black leaf spot of crucifers. PMID:28018402

Unveiling the First Black Holes With JWST:Multi-wavelength Spectral Predictions

NASA Astrophysics Data System (ADS)

Natarajan, Priyamvada; Pacucci, Fabio; Ferrara, Andrea; Agarwal, Bhaskar; Ricarte, Angelo; Zackrisson, Erik; Cappelluti, Nico

2017-04-01

Growing supermassive black holes (˜ {10}9 {M}⊙ ) that power luminous z> 6 quasars from light seeds—the remnants of the first stars—within a Gyr of the Big Bang poses a timing challenge. The formation of massive black hole seeds via direct collapse with initial masses ˜ {10}4{--}{10}5 {M}⊙ alleviates this problem. Viable direct-collapse black hole formation sites, the satellite halos of star-forming galaxies, merge and acquire stars to produce a new, transient class of high-redshift objects, obese black hole galaxies (OBGs). The accretion luminosity outshines that of the stars in OBGs. We predict the multi-wavelength energy output of OBGs and growing Pop III remnants at z = 9 for standard and slim disk accretion, as well as high and low metallicities of the associated stellar population. We derive robust selection criteria for OBGs—a pre-selection to eliminate blue sources, followed by color-color cuts ([{F}090W-{F}220W]> 0;-0.3< [{F}200W-{F}444W]< 0.3) and the ratio of X-ray flux to rest-frame optical flux ({F}X/{F}444W\\gg 1). Our cuts sift out OBGs from other bright, high- and low-redshift contaminants in the infrared. OBGs with predicted {M}{AB}< 25 are unambiguously detectable by the Mid-Infrared Instrument (MIRI), on the upcoming James Webb Space Telescope (JWST). For parameters explored here, growing Pop III remnants with predicted {M}{AB}< 30 will likely be undetectable by JWST. We demonstrate that JWST has the power to discriminate between initial seeding mechanisms.

A technical evaluation of the Nucletron FIRST system: conformance of a remote afterloading brachytherapy seed implantation system to manufacturer specifications and AAPM Task Group report recommendations.

PubMed

Rivard, Mark J; Evans, Dee-Ann Radford; Kay, Ian

2005-01-01

The Fully Integrated Real-time Seed Treatment (FIRST) system by Nucletron has been available in Europe since November 2001 and is being used more and more in Canada and the United States. Like the conventional transrectal ultrasound implant procedure, the FIRST system utilizes an ultrasound probe, needles, and brachytherapy seeds. However, this system is unique in that it (1) utilizes a low-dose-rate brachytherapy seed remote afterloader (the seedSelectron), (2) utilizes 3D image reconstruction acquired from electromechanically controlled, nonstepping rotation of the ultrasound probe, (3) integrates the control of a remote afterloader with electromechanical control of the ultrasound probe for integrating the clinical procedure into a single system, and (4) automates the transfer of planning information and seed delivery to improve quality assurance and radiation safety. This automated delivery system is specifically intended to address reproducibility and accuracy of seed positioning during implantation. The FIRST computer system includes two software environments: SPOT PRO and seedSelectron; both are used to facilitate treatment planning and brachytherapy seed implantation from beginning to completion of the entire procedure. In addition to these features, the system is reported to meet certain product specifications for seed delivery positioning accuracy and reproducibility, seed calibration accuracy and reliability, and brachytherapy dosimetry calculations. Consequently, a technical evaluation of the FIRST system was performed to determine adherence to manufacturer specifications and to the American Association of Physicists in Medicine (AAPM) Task Group Reports 43, 53, 56, 59, and 64 and recommendations of the American Brachytherapy Society (ABS). The United States Nuclear Regulatory Commission (NRC) has recently added Licensing Guidance for the seedSelectron system under 10 CFR 35.1000. Adherence to licensing guidance is made by referencing applicable AAPM

Therapeutic Implications of Black Seed and Its Constituent Thymoquinone in the Prevention of Cancer through Inactivation and Activation of Molecular Pathways

PubMed Central

Rahmani, Arshad H.; Alzohairy, Mohammad A.; Khan, Masood A.; Aly, Salah M.

2014-01-01

The cancer is probably the most dreaded disease in both men and women and also major health problem worldwide. Despite its high prevalence, the exact molecular mechanisms of the development and progression are not fully understood. The current chemotherapy/radiotherapy regime used to treat cancer shows adverse side effect and may alter gene functions. Natural products are generally safe, effective, and less expensive substitutes of anticancer chemotherapeutics. Based on previous studies of their potential therapeutic uses, Nigella sativa and its constituents may be proved as good therapeutic options in the prevention of cancer. Black seeds are used as staple food in the Middle Eastern Countries for thousands of years and also in the treatment of diseases. Earlier studies have shown that N. sativa and its constituent thymoquinone (TQ) have important roles in the prevention and treatment of cancer by modulating cell signaling pathways. In this review, we summarize the role of N. sativa and its constituents TQ in the prevention of cancer through the activation or inactivation of molecular cell signaling pathways. PMID:24959190

Star motion around rotating black hole in the Galactic Center in real time

NASA Astrophysics Data System (ADS)

Dokuchaev, Vyacheslav; Nazarova, Natalia

2017-12-01

The Event Horizon Telescope team intends by the 2020 to resolve the shadow of supermassive black hole SgrA* in the Galactic Center. It would be the first attempt for direct identification of the enigmatic black hole. In other words, it would be the first experimental verification of the General Relativity in the strong field limit. There is a chance to find a star moving on the relativistic orbit close to this black hole. We present the animated numerical model of the gravitational lensing of a star (or any other lighting probe), moving around rotating Kerr black hole in the Galactic Center and viewed by the distant observer.

Protective effect of treatment with black cumin oil on spatial cognitive functions of rats that suffered global cerebrovascular hypoperfusion.

PubMed

Azzubaidi, Marwan Saad; Saxena, Anil Kumar; Talib, Norlelawati Abi; Ahmed, Qamar Uddin; Dogarai, Bashar Bello

2012-01-01

The fixed oil of black cumin seeds, Nigella sativa L. (NSO), has shown considerable antioxidant and anti-inflammatory activities. Chronic cerebral hypoperfusion has been linked to neurodegenerative disorders including Alzheimer's disease (AD) and its subsequent cognitive impairment in which oxidative stress and neuroinflammation are the principal culprits. Cerebrovascular hypoperfusion was experimentally achieved by bilateral common carotid arteries occlusion (2VO) in rats. Morris water maze (MWM) test was employed to assess the effects of NSO on spatial cognitive function before and after 2VO intervention. Rats were divided into long-term memory (LTM) and short-term memory (STM) groups, each was further subdivided into 3 subgroups: sham control, untreated 2VO and NSO treated 2VO group. All subgroups were tested with MWM at the tenth postoperative week. Working memory test results for both sham control and NSO treated groups showed significantly lower escape latency time and total distance travelled than untreated 2VO group. Similarly, LTM and STM MWM tests for sham control and NSO treated groups revealed significantly better maze test performance as compared to untreated 2VO group. Sham control and NSO treated 2VO groups demonstrated superior probe memory test performance as compared to untreated 2VO group. The fixed oil of Nigella sativa seeds has demonstrated noticeable spatial cognitive preservation in rats challenged with chronic cerebral hypoperfusion which indicates a promising prospective neuroprotective effect.

Prediction of canned black bean texture (Phaseolus vulgaris L.) from intact dry seeds using visible/near infrared spectroscopy and hyperspectral imaging data.

PubMed

Mendoza, Fernando A; Cichy, Karen A; Sprague, Christy; Goffnett, Amanda; Lu, Renfu; Kelly, James D

2018-01-01

Texture is a major quality parameter for the acceptability of canned whole beans. Prior knowledge of this quality trait before processing would be useful to guide variety development by bean breeders and optimize handling protocols by processors. The objective of this study was to evaluate and compare the predictive power of visible and near infrared reflectance spectroscopy (visible/NIRS, 400-2498 nm) and hyperspectral imaging (HYPERS, 400-1000 nm) techniques for predicting texture of canned black beans from intact dry seeds. Black beans were grown in Michigan (USA) over three field seasons. The samples exhibited phenotypic variability for canned bean texture due to genetic variability and processing practice. Spectral preprocessing methods (i.e. smoothing, first and second derivatives, continuous wavelet transform, and two-band ratios), coupled with a feature selection method, were tested for optimizing the prediction accuracy in both techniques based on partial least squares regression (PLSR) models. Visible/NIRS and HYPERS were effective in predicting texture of canned beans using intact dry seeds, as indicated by their correlation coefficients for prediction (R pred ) and standard errors of prediction (SEP). Visible/NIRS was superior (R pred = 0.546-0.923, SEP = 7.5-1.9 kg 100 g -1 ) to HYPERS (R pred = 0.401-0.883, SEP = 7.6-2.4 kg 100 g -1 ), which is likely due to the wider wavelength range collected in visible/NIRS. However, a significant improvement was reached in both techniques when the two-band ratios preprocessing method was applied to the data, reducing SEP by at least 10.4% and 16.2% for visible/NIRS and HYPERS, respectively. Moreover, results from using the combination of the three-season data sets based on the two-band ratios showed that visible/NIRS (R pred = 0.886, SEP = 4.0 kg 100 g -1 ) and HYPERS (R pred = 0.844, SEP = 4.6 kg 100 g -1 ) models were consistently successful in predicting texture over a wide range of measurements. Visible

Impact of Membrane-Induced Particle Immobilization on Seeded Growth Monitored by In Situ Liquid Scanning Transmission Electron Microscopy.

PubMed

Weiner, Rebecca G; Chen, Dennis P; Unocic, Raymond R; Skrabalak, Sara E

2016-05-01

In situ liquid cell scanning transmission electron microscopy probes seeded growth in real time. The growth of Pd on Au nanocubes is monitored as a model system to compare growth within a liquid cell and traditional colloidal synthesis. Different growth patterns are observed due to seed immobilization and the highly reducing environment within the liquid cell. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Observational constraints on black hole accretion disks

NASA Technical Reports Server (NTRS)

Liang, Edison P.

1994-01-01

We review the empirical constraints on accretion disk models of stellar-mass black holes based on recent multiwavelength observational results. In addition to time-averaged emission spectra, the time evolutions of the intensity and spectrum provide critical information about the structure, stability, and dynamics of the disk. Using the basic thermal Keplerian disk paradigm, we consider in particular generalizations of the standard optically thin disk models needed to accommodate the extremely rich variety of dynamical phenomena exhibited by black hole candidates ranging from flares of electron-positron annihilations and quasiperiodic oscillations in the X-ray intensity to X-ray novae activity. These in turn provide probes of the disk structure and global geometry. The goal is to construct a single unified framework to interpret a large variety of black hole phenomena. This paper will concentrate on the interface between basic theory and observational data modeling.

Body and diet composition of sympatric black and grizzly bears in the Greater Yellowstone Ecosystem

USGS Publications Warehouse

Schwartz, Charles C.; Fortin, Jennifer K.; Teisberg, Justin E.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

2013-01-01

The Greater Yellowstone Ecosystem (GYE) has experienced changes in the distribution and availability of grizzly bear (Ursus arctos) food resources in recent decades. The decline of ungulates, fish, and whitebark pine seeds (Pinus albicaulis) has prompted questions regarding their ability to adapt. We examined body composition and diet of grizzly bears using bioelectrical impedance and stable isotopes to determine if 1) we can detect a change in diet quality associated with the decline in either ungulates or whitebark pine, and 2) the combined decline in ungulates, fish, and pine seeds resulted in a change in grizzly bear carrying capacity in the GYE. We contrasted body fat and mass in grizzly bears with a potential competitor, the American black bear (Ursus americanus), to address these questions. Grizzly bears assimilated more meat into their diet and were in better body condition than black bears throughout the study period, indicating the decline in ungulate resources did not affect grizzly bears more than black bears. We also found no difference in autumn fat levels in grizzly bears in years of good or poor pine seed production, and stable isotope analyses revealed this was primarily a function of switching to meat resources during poor seed-producing years. This dietary plasticity was consistent over the course of our study. We did not detect an overall downward trend in either body mass or the fraction of meat assimilated into the diet by grizzly bears over the past decade, but we did detect a downward trend in percent body fat in adult female grizzly bears after 2006. Whether this decline is an artifact of small sample size or due to the population reaching the ecological carrying capacity of the Yellowstone ecosystem warrants further investigation.

In situ analysis of soybeans and nuts by probe electrospray ionization mass spectrometry.

PubMed

Petroselli, Gabriela; Mandal, Mridul K; Chen, Lee C; Hiraoka, Kenzo; Nonami, Hiroshi; Erra-Balsells, Rosa

2015-04-01

The probe electrospray ionization (PESI) is an ESI-based ionization technique that generates electrospray from the tip of a solid metal needle. In the present work, we describe the PESI mass spectra obtained by in situ measurement of soybeans and several nuts (peanuts, walnuts, cashew nuts, macadamia nuts and almonds) using different solid needles as sampling probes. It was found that PESI-MS is a valuable approach for in situ lipid analysis of these seeds. The phospholipid and triacylglycerol PESI spectra of different nuts and soybean were compared by principal component analysis (PCA). PCA shows significant differences among the data of each family of seeds. Methanolic extracts of nuts and soybean were exposed to air and sunlight for several days. PESI mass spectra were recorded before and after the treatment. Along the aging of the oil (rancidification), the formation of oxidated species with variable number of hydroperoxide groups could be observed in the PESI spectra. The relative intensity of oxidated triacylglycerols signals increased with days of exposition. Monitoring sensitivity of PESI-MS was high. This method provides a fast, simple and sensitive technique for the analysis (detection and characterization) of lipids in seed tissue and degree of oxidation of the oil samples. Copyright © 2015 John Wiley & Sons, Ltd.

Searching for intermediate-mass black holes in extremely-metal poor galaxies

NASA Astrophysics Data System (ADS)

Mezcua, Mar

2016-09-01

Extremely metal-poor dwarf galaxies (XMPs) are star-forming, low-mass galaxies with metallicites highly sub-solar. Their regions of star formation could be triggered by the accretion of pristine gas from the cosmic web and harbour Population III stars. XMPs are thus ideal laboratories for searching for the seed black holes or intermediate-mass black holes (IMBHs) that populated the early Universe. The combination of X-ray, radio and optical observations offer the best tool for detecting such IMBHs in the local Universe. We propose Chandra observations of a sample of XMPs whose optical spectra indicate the possible presence of an active black hole of 1e4 - 1e6 Msun. The Chandra data could confirm this and yield the first detection of an IMBH in these type of galaxies.

Seed-to-seed-to-seed growth and development of Arabidopsis in microgravity.

PubMed

Link, Bruce M; Busse, James S; Stankovic, Bratislav

2014-10-01

Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves.

Black holes with su(N) gauge field hair and superconducting horizons

NASA Astrophysics Data System (ADS)

Shepherd, Ben L.; Winstanley, Elizabeth

2017-01-01

We present new planar dyonic black hole solutions of the su(N) Einstein-Yang-Mills equations in asymptotically anti-de Sitter space-time, focussing on su(2) and su(3) gauge groups. The magnetic part of the gauge field forms a condensate close to the planar event horizon. We compare the free energy of a non-Abelian hairy black hole with that of an embedded Reissner-Nordström-anti-de Sitter (RN-AdS) black hole having the same Hawking temperature and electric charge. We find that the hairy black holes have lower free energy. We present evidence that there is a phase transition at a critical temperature, above which the only solutions are embedded RN-AdS black holes. At the critical temperature, an RN-AdS black hole can decay into a hairy black hole, and it is thermodynamically favourable to do so. Working in the probe limit, we compute the frequency-dependent conductivity, and find that enlarging the gauge group from su(2) to su(3) eliminates a divergence in the conductivity at nonzero frequency.

Physiological traits of endornavirus-infected and endornavirus-free common bean (Phaseolus vulgaris) cv Black Turtle Soup.

PubMed

Khankhum, S; Valverde, R A

2018-04-01

This study evaluated the physiological traits of eight lines of common bean (Phaseolus vulgaris) cv. Black Turtle Soup, four of which were double-infected with Phaseolus vulgaris endornavirus 1 and Phaseolus vulgaris endornavirus 2, and four of which were endornavirus-free. Plants from all eight lines were morphologically similar and did not show statistically significant differences in plant height, wet weight, number of days to flowering and pod formation, pods per plant, pod thickness, seed size, number of seeds per pod, and anthocyanin content. However, the endornavirus-infected lines had faster seed germination, longer radicle, lower chlorophyll content, higher carotene content, longer pods, and higher weight of 100 seeds, all of which were statistically significant. The endornaviruses were not associated with visible pathogenic effects.

Reproductive potential of balsam fir (Abies balsamea), white spruce (Picea glauca), and black spruce (P. mariana) at the ecotone between mixedwood and coniferous forests in the boreal zone of western Quebec.

PubMed

Messaoud, Yassine; Bergeron, Yves; Asselin, Hugo

2007-05-01

The reproductive potentials of balsam fir and white spruce (co-dominants in mixedwood forests) and black spruce (dominant in coniferous forests) were studied to explain the location of the ecotone between the two forest types in the boreal zone of Quebec. Four sites were selected along a latitudinal gradient crossing the ecotone. Cone crop, number of seeds per cone, percentage filled seeds, and percentage germination were measured for each species. Balsam fir and white spruce cone crops were significantly lower in the coniferous than in the mixedwood forest, while black spruce had greater crop constancy and regularity between both forest types. Mast years were more frequent for black spruce than for balsam fir in both forest types (mast year data not available for white spruce). The number of seeds per cone was more related to cone size than to forest type for all species. Black spruce produced more filled seeds in the coniferous forest than balsam fir or white spruce. The sum of growing degree-days and the maximum temperature of the warmest month (both for the year prior to cone production) significantly affected balsam fir cone production. The climate-related northward decrease in reproductive potential of balsam fir and white spruce could partly explain the position of the northern limit of the mixedwood forest. This could change drastically, however, as the ongoing climate warming might cancel this competitive advantage of black spruce.

Seed-to-Seed-to-Seed Growth and Development of Arabidopsis in Microgravity

PubMed Central

Link, Bruce M.; Busse, James S.

2014-01-01

Abstract Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves. Key Words: Arabidopsis—Branch—Inflorescence—Microgravity—Morphology—Seed—Space. Astrobiology 14, 866–875. PMID:25317938

Faith in a seed: on the origins of equatorial plasma bubbles

NASA Astrophysics Data System (ADS)

Retterer, J. M.; Roddy, P.

2014-05-01

Our faith in the seeds of equatorial plasma irregularities holds that there will generally always be density perturbations sufficient to provide the seeds for irregularity development whenever the Rayleigh-Taylor instability is active. When the duration of the time of the Rayleigh-Taylor instability is short, however, the magnitude of the seed perturbations can make a difference in whether the irregularities have a chance to grow to a strength at which the nonlinear development of plumes occurs. In addition, the character of the resulting irregularities reflects the characteristics of the initial seed density perturbation, e.g., their strength, spacing, and, to some extent, their spatial scales, and it is important to know the seeds to help determine the structure of the developed irregularities. To this end, we describe the climatology of daytime and early-evening density irregularities that can serve as seeds for later development of plumes, as determined from the Planar Langmuir Probe (PLP) plasma density measurements on the C/NOFS (Communication and Navigation Outage Forecast System) satellite mission, presenting their magnitude as a function of altitude, latitude, longitude, local time, season, and phase in the solar cycle (within the C/NOFS observation era). To examine some of the consequences of these density perturbations, they are used as initial conditions for the PBMOD PBMOD (Retterer, 2010a) 3-D irregularity model to follow their potential development into larger-amplitude irregularities, plumes, and radio scintillation. "Though I do not believe that a pla[sma bubble] will spring up where no seed has been, I have great faith in a seed. Convince me that you have a seed there, and I am prepared to expect wonders." - Henry David Thoreau

Mountain-climbing bears protect cherry species from global warming through vertical seed dispersal.

PubMed

Naoe, Shoji; Tayasu, Ichiro; Sakai, Yoichiro; Masaki, Takashi; Kobayashi, Kazuki; Nakajima, Akiko; Sato, Yoshikazu; Yamazaki, Koji; Kiyokawa, Hiroki; Koike, Shinsuke

2016-04-25

In a warming climate, temperature-sensitive plants must move toward colder areas, that is, higher latitude or altitude, by seed dispersal [1]. Considering that the temperature drop with increasing altitude (-0.65°C per 100 m altitude) is one hundred to a thousand times larger than that of the equivalent latitudinal distance [2], vertical seed dispersal is probably a key process for plant escape from warming temperatures. In fact, plant geographical distributions are tracking global warming altitudinally rather than latitudinally, and the extent of tracking is considered to be large in plants with better-dispersed traits (e.g., lighter seeds in wind-dispersed plants) [1]. However, no study has evaluated vertical seed dispersal itself due to technical difficulty or high cost. Here, we show using a stable oxygen isotope that black bears disperse seeds of wild cherry over several hundred meters vertically, and that the dispersal direction is heavily biased towards the mountain tops. Mountain climbing by bears following spring-to-summer plant phenology is likely the cause of this biased seed dispersal. These results suggest that spring- and summer-fruiting plants dispersed by animals may have high potential to escape global warming. Our results also indicate that the direction of vertical seed dispersal can be unexpectedly biased, and highlight the importance of considering seed dispersal direction to understand plant responses to past and future climate change. Copyright © 2016 Elsevier Ltd. All rights reserved.

Supersonic gas streams enhance the formation of massive black holes in the early universe.

PubMed

Hirano, Shingo; Hosokawa, Takashi; Yoshida, Naoki; Kuiper, Rolf

2017-09-29

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. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Black and brown pigment gallstones differ in microstructure and microcomposition.

PubMed

Malet, P F; Takabayashi, A; Trotman, B W; Soloway, R D; Weston, N E

1984-01-01

The two subtypes of pigment gallstones, black and brown stones, differ in chemical composition and pathogenesis. We examined a black bilirubinate stone and a black phosphate stone (which represented opposite ends of the compositional spectrum of black noncarbonate stones), a black carbonate stone, and a brown pigment stone using scanning electron microscopy and microchemical techniques to determine if stone microstructure and microcomposition reflected different patterns of formation. The cross-sectional surfaces of the black bilirubinate and black phosphate stones were smooth and homogenous. Electron probe microanalysis demonstrated high concentrations of sulfur and copper in the center of the black bilirubinate stone; sulfur was in a low valence state consistent with disulfide linkages in proteins. The brown stone was rough-surfaced with lamellated bands on cross-section. The lighter-colored bands in this stone contained virtually all of the detected calcium palmitate, while the darker sections contained much more calcium bilirubinate. Plasma oxygen etching demonstrated a network of protein interdigitating with calcium bilirubinate salts in the black bilirubinate and black phosphate stones but not in the black carbonate or brown stones. Argon ion etching demonstrated that calcium bilirubinate was in a closely packed rod-shaped arrangement in all three black stones but not in the brown stone. We conclude that the marked differences in structure and composition between the black noncarbonate and brown pigment gallstones support the hypothesis that the two major pigment gallstone types form by different mechanisms. In addition, the layered structures of the black carbonate and brown stones suggest that stone growth is affected by cyclic changes in biliary composition.

Differential seed handling by two African primates affects seed fate and establishment of large-seeded trees

NASA Astrophysics Data System (ADS)

Gross-Camp, Nicole D.; Kaplin, Beth A.

2011-11-01

We examined the influence of seed handling by two semi-terrestrial African forest primates, chimpanzees ( Pan troglodytes) and l'Hoest's monkeys ( Cercopithecus lhoesti), on the fate of large-seeded tree species in an afromontane forest. Chimpanzees and l'Hoest's monkeys dispersed eleven seed species over one year, with quantity and quality of dispersal varying through time. Primates differed in their seed handling behaviors with chimpanzees defecating large seeds (>0.5 cm) significantly more than l'Hoest's. Furthermore, they exhibited different oral-processing techniques with chimpanzees discarding wadges containing many seeds and l'Hoest's monkeys spitting single seeds. A PCA examined the relationship between microhabitat characteristics and the site where primates deposited seeds. The first two components explained almost half of the observed variation. Microhabitat characteristics associated with sites where seeds were defecated had little overlap with those characteristics describing where spit seeds arrived, suggesting that seed handling in part determines the location where seeds are deposited. We monitored a total of 552 seed depositions through time, recording seed persistence, germination, and establishment. Defecations were deposited significantly farther from an adult conspecific than orally-discarded seeds where they experienced the greatest persistence but poorest establishment. In contrast, spit seeds were deposited closest to an adult conspecific but experienced the highest seed establishment rates. We used experimental plots to examine the relationship between seed handling, deposition site, and seed fate. We found a significant difference in seed handling and fate, with undispersed seeds in whole fruits experiencing the lowest establishment rates. Seed germination differed by habitat type with open forest experiencing the highest rates of germination. Our results highlight the relationship between primate seed handling and deposition site and seed

BLACK HOLE MASS ESTIMATES AND RAPID GROWTH OF SUPERMASSIVE BLACK HOLES IN LUMINOUS z ∼ 3.5 QUASARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zuo, Wenwen; Wu, Xue-Bing; Fan, Xiaohui

2015-02-01

We present new near-infrared (IR) observations of the Hβ λ4861 and Mg II λ2798 lines for 32 luminous quasars with 3.2 < z < 3.9 using the Palomar Hale 200 inch telescope and the Large Binocular Telescope. We find that the Mg II FWHM is well correlated with the Hβ FWHM, confirming itself as a good substitute for the Hβ FWHM in the black hole mass estimates. The continuum luminosity at 5100 Å well correlates with the continuum luminosity at 3000 Å and the broad emission line luminosities (Hβ and Mg II). With simultaneous near-IR spectroscopy of the Hβ andmore » Mg II lines to exclude the influences of flux variability, we are able to evaluate the reliability of estimating black hole masses based on the Mg II line for high redshift quasars. With the reliable Hβ line based black hole mass and Eddington ratio estimates, we find that the z ∼ 3.5 quasars in our sample have black hole masses 1.90 × 10{sup 9} M {sub ☉} ≲ M {sub BH} ≲ 1.37 × 10{sup 10} M {sub ☉}, with a median of ∼5.14 × 10{sup 9} M {sub ☉} and are accreting at Eddington ratios between 0.30 and 3.05, with a median of ∼1.12. Assuming a duty cycle of 1 and a seed black hole mass of 10{sup 4} M {sub ☉}, we show that the z ∼ 3.5 quasars in this sample can grow to their estimated black hole masses within the age of the universe at their redshifts.« less

Theory-Agnostic Constraints on Black-Hole Dipole Radiation with Multiband Gravitational-Wave Astrophysics.

PubMed

Barausse, Enrico; Yunes, Nicolás; Chamberlain, Katie

2016-06-17

The aLIGO detection of the black-hole binary GW150914 opens a new era for probing extreme gravity. Many gravity theories predict the emission of dipole gravitational radiation by binaries. This is excluded to high accuracy in binary pulsars, but entire classes of theories predict this effect predominantly (or only) in binaries involving black holes. Joint observations of GW150914-like systems by aLIGO and eLISA will improve bounds on dipole emission from black-hole binaries by 6 orders of magnitude relative to current constraints, provided that eLISA is not dramatically descoped.

Journey to the MBH-σ relation: the fate of low-mass black holes in the Universe

NASA Astrophysics Data System (ADS)

Volonteri, Marta; Natarajan, Priyamvada

2009-12-01

In this paper, we explore the establishment and evolution of the empirical correlation between black hole mass (MBH) and velocity dispersion (σ) with redshift. We trace the growth and accretion history of massive black holes (MBHs) starting from high-redshift seeds that are planted via physically motivated prescriptions. Two seeding models are explored in this work: `light seeds', derived from Population III remnants, and `heavy seeds', derived from direct gas collapse. Even though the seeds themselves do not satisfy the MBH-σ relation initially, we find that the relation can be established and maintained at all times if self-regulating accretion episodes are associated with major mergers. The massive end of the MBH-σ relation is established early, and lower mass MBHs migrate on to it as hierarchical merging proceeds. How MBHs migrate towards the relation depends critically on the seeding prescription. Light seeds initially lie well below the MBH-σ relation, and MBHs can grow via steady accretion episodes unhindered by self-regulation. In contrast, for the heavy seeding model, MBHs are initially over-massive compared to the empirical correlation, and the host haloes assemble prior to kick-starting the growth of the MBH. We find that the existence of the MBH-σ correlation is purely a reflection of the merging hierarchy of massive dark matter haloes. The slope and scatter of the relation however appear to be a consequence of the seeding mechanism and the self-regulation prescription. We expect flux limited active galactic nucleus surveys to select MBHs that have already migrated on to the MBH-σ relation. Similarly, the Laser Interferometer Space Antenna (LISA) is also likely to be biased towards detecting merging MBHs that preferentially inhabit the MBH-σ. These results are a consequence of major mergers being more common at high redshift for the most massive, biased, galaxies that host MBHs which have already migrated on to the MBH-σ relation. We also

Observing the contour profile of a Kerr-Sen black hole

NASA Astrophysics Data System (ADS)

Lan, X. G.; Pu, J.

2018-06-01

In this paper, the shadow and the corresponding naked singularity cast by a Kerr-Sen black hole are studied. It is found that the shadow of a rotating black hole would be a dark zone surrounded by a deformed circle, and the shadow is distorted more away from a circle when the black hole approaches the extremal case. Besides, it is shown that the mean radius of the shadow decreases and distortion parameter increases with the increasing of charge, respectively. However, the mean radius and the distortion parameter vary complicatedly with the change of spin parameter. In the beginning, both observables decrease rapidly with the increasing of specific angular momentum, nevertheless, they increase slightly in the latter part. These results show that there would be a significant effect of the spin on the shadows, which would be of great importance for probing the nature of the black hole.

Seed dispersal and movement patterns in two species of Ceratogymna hornbills in a West African tropical lowland forest.

PubMed

Holbrook, Kimberly M; Smith, Thomas B

2000-10-01

We studied two species of Ceratogymna hornbills, the black-casqued hornbill, C. atrata, and the white-thighed hornbill, C. cylindricus, in the tropical forests of Cameroon, to understand their movement patterns and evaluate their effectiveness as seed dispersers. To estimate hornbill contribution to a particular tree species' seed shadow we combined data from movements, determined by radio-tracking, with data from seed passage trials. For 13 individuals tracked over 12 months, home range varied between 925 and 4,472 ha, a much larger area than reported for other African avian frugivores. Seed passage times ranged from 51 to 765 min, with C. atrata showing longer passage times than C. cylindricus, and larger seeds having longer gut retention times than smaller seeds. Combining these data, we estimated that seed shadows were extensive for the eight tree species examined, with approximately 80% of seeds moved more than 500 m from the parent plant. Maximum estimated dispersal distances for larger seeds were 6,919 and 3,558 m for C. atrata and C. cylindricus, respectively. The extent of hornbill seed shadows suggests that their influence in determining forest structure will likely increase as other larger mammalian dispersers are exterminated.

New aspect of critical nonlinearly charged black hole

NASA Astrophysics Data System (ADS)

Hendi, S. H.; Taghadomi, Z. S.; Corda, C.

2018-04-01

The motion of a point charged particle moving in the background of the critical power Maxwell charged AdS black holes in a probe approximation is studied. The extended phase space, where the cosmological constant appears as a pressure, is regarded and the effective potential is investigated. At last, the mass-to-charge ratio and the large q limit are studied.

AGN Variability: Probing Black Hole Accretion

NASA Astrophysics Data System (ADS)

Moreno, Jackeline; O'Brien, Jack; Vogeley, Michael S.; Richards, Gordon T.; Kasliwal, Vishal P.

2017-01-01

We combine the long temporal baseline of Sloan Digital Sky Survey (SDSS) for quasars in Stripe 82 with the high precision photometry of the Kepler/K2 Satellite to study the physics of optical variability in the accretion disk and supermassive black hole engine. We model the lightcurves directly as Continuous-time Auto Regressive Moving Average processes (C-ARMA) with the Kali analysis package (Kasliwal et al. 2016). These models are extremely robust to irregular sampling and can capture aperiodic variability structure on various timescales. We also estimate the power spectral density and structure function of both the model family and the data. A Green's function kernel may also be estimated for the resulting C-ARMA parameter fit, which may be interpreted as the response to driving impulses such as hotspots in the accretion disk. We also examine available spectra for our AGN sample to relate observed and modelled behavior to spectral properties. The objective of this work is twofold: to explore the proper physical interpretation of different families of C-ARMA models applied to AGN optical flux variability and to relate empirical characteristic timescales of our AGN sample to physical theory or to properties estimated from spectra or simulations like the disk viscosity and temperature. We find that AGN with strong variability features on timescales resolved by K2 are well modelled by a low order C-ARMA family while K2 lightcurves with weak amplitude variability are dominated by outliers and measurement errors which force higher order model fits. This work explores a novel approach to combining SDSS and K2 data sets and presents recovered characteristic timescales of AGN variability.

Using Phase Space Density Profiles to Investigate the Radiation Belt Seed Population

NASA Astrophysics Data System (ADS)

Boyd, A. J.; Spence, H.; Reeves, G. D.; Blake, J. B.; Fennell, J. F.; Claudepierre, S. G.; Turner, D. L.

2013-12-01

It is believed that particles with energies of 100s of keV play a critical role in the acceleration of electrons within the radiation belt. Through wave particle interactions, these so called 'seed electrons' can be accelerated up to energies greater than 1 MeV. Using data from the MagEIS (Magnetic Electron Ion Spectrometer) Instrument onboard the Van Allen Probes we calculate phase space density within the radiation belts over a wide range of mu and K values. These phase space density profiles are combined with those from THEMIS, in order to see how the phase space density evolves over a large range of L*. In this presentation we examine how the seed electron population evolves in both time and L* during acceleration events. Comparing this to the evolution of the higher mu electron population allows us to determine what role the seed electrons played in the acceleration process. Finally, we compare several of these storms to examine the importance of the seed population to the acceleration process.

SOME ENGINEERING PROPERTIES OF SHELLED AND KERNEL TEA (Camellia sinensis) SEEDS.

PubMed

Altuntas, Ebubekir; Yildiz, Merve

2017-01-01

Camellia sinensis is the source of tea leaves and it is an economic crop now grown around the World. Tea seed oil has been used for cooking in China and other Asian countries for more than a thousand years. Tea is the most widely consumed beverages after water in the world. It is mainly produced in Asia, central Africa, and exported throughout the World. Some engineering properties (size dimensions, sphericity, volume, bulk and true densities, friction coefficient, colour characteristics and mechanical behaviour as rupture force of shelled and kernel tea ( Camellia sinensis ) seeds were determined in this study. This research was carried out for shelled and kernel tea seeds. The shelled tea seeds used in this study were obtained from East-Black Sea Tea Cooperative Institution in Rize city of Turkey. Shelled and kernel tea seeds were characterized as large and small sizes. The average geometric mean diameter and seed mass of the shelled tea seeds were 15.8 mm, 10.7 mm (large size); 1.47 g, 0.49 g (small size); while the average geometric mean diameter and seed mass of the kernel tea seeds were 11.8 mm, 8 mm for large size; 0.97 g, 0.31 g for small size, respectively. The sphericity, surface area and volume values were found to be higher in a larger size than small size for the shelled and kernel tea samples. The shelled tea seed's colour intensity (Chroma) were found between 59.31 and 64.22 for large size, while the kernel tea seed's chroma values were found between 56.04 68.34 for large size, respectively. The rupture force values of kernel tea seeds were higher than shelled tea seeds for the large size along X axis; whereas, the rupture force values of along X axis were higher than Y axis for large size of shelled tea seeds. The static coefficients of friction of shelled and kernel tea seeds for the large and small sizes higher values for rubber than the other friction surfaces. Some engineering properties, such as geometric mean diameter, sphericity, volume, bulk

Probing general relativistic precession around stellar-mass black holes with tomography and polarimetry

NASA Astrophysics Data System (ADS)

Ingram, A.

2017-10-01

Accreting stellar-mass black holes often show a quasi-periodic oscillation (QPO) in their X-ray flux, and an iron emission line in their X-ray spectrum. The iron line is generated through disc reflection, and its shape is distorted by rapid orbital motion and gravitational redshift. The physical origin of the QPO has long been debated, but is often attributed to Lense-Thirring precession, a General Relativistic effect causing the inner flow to precess as the spinning black hole twists up the surrounding space-time. This predicts a characteristic rocking of the iron line between red- and blueshift as the receding and approaching sides of the disc are respectively illuminated. I will first talk about our XMM-Newton and NuSTAR observations of the black hole binary H 1743-322 in which the line energy varies systematically over the ˜ 4 s QPO cycle, as predicted. This result has enabled us to map the inner accretion disc using tomographic techniques for the first time. I will then talk about the quasi-periodic swings in X-ray polarisation angle predicted by the precession model, and show how we can go about measuring such swings with the recently selected NASA Small explorer mission IXPE and proposed missions such as XIPE and eXTP.

Survival and growth of black walnut families after 7 years in West Virginia

Treesearch

G. W. Wendel; Donald E. Dorn; Donald E. Dorn

1985-01-01

Average survival, 7-year stem diameter, and stem diameter growth differed significantly among 34 black walnut families planted in West Virginia. Average total height, height growth, and diameter at breast height were not significantly different among families. Families were from seed collected in West Virginia, Pennsylvania, North Carolina, and Tennessee. The 7-year...

Stable isotopes identify dietary changes associated with beak deformities in Black-Capped Chickadees (Poecile atricapillus)

USGS Publications Warehouse

Van Hemert, Caroline; Handel, Colleen M.; O'Brien, Diane M.

2012-01-01

A large number of beak deformities of unknown etiology have recently been reported in Black-capped Chickadees (Poecile atricapillus) and other resident avian species in Alaska. We investigated the potential association between diet and beak deformities. We analyzed carbon (δ13C) and nitrogen (δ15N) isotopes in whole blood of Black-capped Chickadees captured at three semiurban sites in south-central Alaska. For dietary analysis, we included natural foods (arthropods, seeds, and berries) and anthropogenic items commonly provided in bird feeders (sunflower seeds, peanut butter, and suet). Blood samples from individuals with beak deformities exhibited lower δ15N values and more variable δ13C values than birds with normal beaks. Isotopic values of blood also differed by location for both carbon and nitrogen, but we did not detect a difference in natural dietary items across the three sites. Contributions of individual diet items differed between birds with and without beak deformities, a pattern that likely reflected reduced function of the beak. Affected birds generally consumed fewer arthropods and sunflower seeds and more peanut butter and natural seeds and berries. Although some individuals with beak deformities relied heavily on feeder foods, we did not find evidence of an anthropogenic food source shared by all affected birds. In addition, dietary differences were most pronounced for moderately to severely affected birds, which suggests that these differences are more likely to be a consequence than a cause of deformities.

Black holes and gravitational waves in models of minicharged dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cardoso, Vitor; Perimeter Institute for Theoretical Physics,31 Caroline Street North Waterloo, Ontario N2L 2Y5; Macedo, Caio F.B.

In viable models of minicharged dark matter, astrophysical black holes might be charged under a hidden U(1) symmetry and are formally described by the same Kerr-Newman solution of Einstein-Maxwell theory. These objects are unique probes of minicharged dark matter and dark photons. We show that the recent gravitational-wave detection of a binary black-hole coalescence by aLIGO provides various observational bounds on the black hole’s charge, regardless of its nature. The pre-merger inspiral phase can be used to constrain the dipolar emission of (ordinary and dark) photons, whereas the detection of the quasinormal modes set an upper limit on the finalmore » black hole’s charge. By using a toy model of a point charge plunging into a Reissner-Nordstrom black hole, we also show that in dynamical processes the (hidden) electromagnetic quasinormal modes of the final object are excited to considerable amplitude in the gravitational-wave spectrum only when the black hole is nearly extremal. The coalescence produces a burst of low-frequency dark photons which might provide a possible electromagnetic counterpart to black-hole mergers in these scenarios.« less

Black holes, hidden symmetries, and complete integrability

NASA Astrophysics Data System (ADS)

Frolov, Valeri P.; Krtouš, Pavel; Kubizňák, David

2017-11-01

The study of higher-dimensional black holes is a subject which has recently attracted vast interest. Perhaps one of the most surprising discoveries is a realization that the properties of higher-dimensional black holes with the spherical horizon topology and described by the Kerr-NUT-(A)dS metrics are very similar to the properties of the well known four-dimensional Kerr metric. This remarkable result stems from the existence of a single object called the principal tensor. In our review we discuss explicit and hidden symmetries of higher-dimensional Kerr-NUT-(A)dS black hole spacetimes. We start with discussion of the Killing and Killing-Yano objects representing explicit and hidden symmetries. We demonstrate that the principal tensor can be used as a "seed object" which generates all these symmetries. It determines the form of the geometry, as well as guarantees its remarkable properties, such as special algebraic type of the spacetime, complete integrability of geodesic motion, and separability of the Hamilton-Jacobi, Klein-Gordon, and Dirac equations. The review also contains a discussion of different applications of the developed formalism and its possible generalizations.

Black holes, hidden symmetries, and complete integrability.

PubMed

Frolov, Valeri P; Krtouš, Pavel; Kubizňák, David

2017-01-01

The study of higher-dimensional black holes is a subject which has recently attracted vast interest. Perhaps one of the most surprising discoveries is a realization that the properties of higher-dimensional black holes with the spherical horizon topology and described by the Kerr-NUT-(A)dS metrics are very similar to the properties of the well known four-dimensional Kerr metric. This remarkable result stems from the existence of a single object called the principal tensor. In our review we discuss explicit and hidden symmetries of higher-dimensional Kerr-NUT-(A)dS black hole spacetimes. We start with discussion of the Killing and Killing-Yano objects representing explicit and hidden symmetries. We demonstrate that the principal tensor can be used as a "seed object" which generates all these symmetries. It determines the form of the geometry, as well as guarantees its remarkable properties, such as special algebraic type of the spacetime, complete integrability of geodesic motion, and separability of the Hamilton-Jacobi, Klein-Gordon, and Dirac equations. The review also contains a discussion of different applications of the developed formalism and its possible generalizations.

Black holes in multi-fractional and Lorentz-violating models

NASA Astrophysics Data System (ADS)

Calcagni, Gianluca; Rodríguez Fernández, David; Ronco, Michele

2017-05-01

We study static and radially symmetric black holes in the multi-fractional theories of gravity with q-derivatives and with weighted derivatives, frameworks where the spacetime dimension varies with the probed scale and geometry is characterized by at least one fundamental length ℓ _*. In the q-derivatives scenario, one finds a tiny shift of the event horizon. Schwarzschild black holes can present an additional ring singularity, not present in general relativity, whose radius is proportional to ℓ _*. In the multi-fractional theory with weighted derivatives, there is no such deformation, but non-trivial geometric features generate a cosmological-constant term, leading to a de Sitter-Schwarzschild black hole. For both scenarios, we compute the Hawking temperature and comment on the resulting black-hole thermodynamics. In the case with q-derivatives, black holes can be hotter than usual and possess an additional ring singularity, while in the case with weighted derivatives they have a de Sitter hair of purely geometric origin, which may lead to a solution of the cosmological constant problem similar to that in unimodular gravity. Finally, we compare our findings with other Lorentz-violating models.

Black holes in multi-fractional and Lorentz-violating models.

PubMed

Calcagni, Gianluca; Rodríguez Fernández, David; Ronco, Michele

2017-01-01

We study static and radially symmetric black holes in the multi-fractional theories of gravity with q -derivatives and with weighted derivatives, frameworks where the spacetime dimension varies with the probed scale and geometry is characterized by at least one fundamental length [Formula: see text]. In the q -derivatives scenario, one finds a tiny shift of the event horizon. Schwarzschild black holes can present an additional ring singularity, not present in general relativity, whose radius is proportional to [Formula: see text]. In the multi-fractional theory with weighted derivatives, there is no such deformation, but non-trivial geometric features generate a cosmological-constant term, leading to a de Sitter-Schwarzschild black hole. For both scenarios, we compute the Hawking temperature and comment on the resulting black-hole thermodynamics. In the case with q -derivatives, black holes can be hotter than usual and possess an additional ring singularity, while in the case with weighted derivatives they have a de Sitter hair of purely geometric origin, which may lead to a solution of the cosmological constant problem similar to that in unimodular gravity. Finally, we compare our findings with other Lorentz-violating models.

Seed harvesting is influenced by associational effects in mixed seed neighbourhoods, not just by seed density

USGS Publications Warehouse

Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan; Klinger, Robert C.

2013-01-01

Rodents frequently forage in a density-dependent manner, increasing harvesting in patches with greater seed densities. Although seldom considered, seed harvesting may also depend on the species identities of other individuals in the seed neighbourhood. When the seed harvest of a focal species increases in association with another seed species, the focal species suffers from Associational Susceptibility. In contrast, if seeds of the focal species are harvested less when in association with a second species, the focal species benefits from Associational Resistance.To evaluate density dependence and associational effects among seeds in mixtures, we conducted seed removal experiments using a completely additive design patterned after a two-species competition experiment using seeds of either Achnatherum hymenoides(Indian ricegrass), Leymus cinereus (basin wildrye) or Pseudoroegneria spicata (bluebunch wheatgrass), all native perennial grasses, combined with seeds of Bromus tectorum(cheatgrass), a non-native annual grass. The experiment involved placing five fixed quantities of the native seeds mixed with five fixed quantities of B. tectorum seeds in a factorial design, resulting in 35 seed mixture combinations. The seed-eating rodent community at our study sites, in order of abundance, is composed of Peromyscus maniculatus (North American deer mouse), Dipodomys ordii (Ord's kangaroo rat) and Perognathus parvus (Great Basin pocket mouse).Native seed harvesting was density dependent, with a greater proportion of seeds being harvested as density increased. In the mixed density model, the presence of B. tectorumdid not affect harvest of any of the native species' seeds when analysed individually. However, when all three native species were analysed together, increasing quantities of B. tectorum resulted in reduced harvest of native seeds, demonstrating weak but significant Associational Resistance. In contrast, harvest of B. tectorum seeds increased

Penile erection responses of Nigella sativa seed extract on isolated rat corpus cavernosum

NASA Astrophysics Data System (ADS)

Aminyoto, M.; Ismail, S.

2018-04-01

Nigella sativa L. (NS) from Ranunculaceae family is known as black cumin in Indonesia. The seed has been used as an aphrodisiac in ethnobotanical studies and reported to have pharmacological activities such as antihypertensive through the relaxant effect of vascular smooth muscles but the direct effect to the blood vessels of the corpus cavernosum is still unknown. The purpose of this study was to examine the response of NS seed extract on penile erection in vitro. NS seeds were macerated in ethanol solvent for three days in room temperature and repeated for two times. Penile erection responses was assessed using isolated rat corpus cavernosum in Krebs-Henseleit solution, temperature 37°C, pH 7.4, aerated with carbogen gas. After acclimation, corpus cavernosum was contracted with a phenylephrine solution. Ethanolic extract of NS seeds or control solution were given after reaching the plateu phase of the highest contraction. This study showed that the contraction response of the corpus cavernosum decreased after addition of NS extract and this action was increased with the addition of the extract concentration. This study concluded that NS seed ethanol extract affects the penile erection response directly through the relaxation of blood vessels in the corpus cavernosum.

Chandra Sees Remarkable Eclipse of Black Hole

NASA Astrophysics Data System (ADS)

2007-04-01

Chandra X-ray Image of NGC 1365 "Thanks to this eclipse, we were able to probe much closer to the edge of this black hole than anyone has been able to before," said co-author Martin Elvis from CfA. "Material this close in will likely cross the event horizon and disappear from the universe in about a hundred years, a blink of an eye in cosmic terms." In addition to measuring the size of this disk of material, Risaliti and his colleagues were also able to estimate the location of the dense gas cloud that eclipsed the X-ray source and central black hole. The Chandra data show that this cloud is one hundredth of a light year from the black hole's event horizon, or 300 times closer than generally thought. "AGN include the brightest objects in the Universe and are powerful probes of the early universe. So, it's vital to understand their basic structure," said Risaliti. "It turns out that we still have work to do to understand these monsters." A series of six Chandra observations of NGC 1365 were made every two days over a period of two weeks in April 2006. During five of the observations, high energy X-rays from the central X-ray source were visible, but in the second one - corresponding to the eclipse - they were not. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Shining in the dark: the spectral evolution of the first black holes

NASA Astrophysics Data System (ADS)

Pacucci, Fabio; Ferrara, Andrea; Volonteri, Marta; Dubus, Guillaume

2015-12-01

Massive black hole (MBH) seeds at redshift z ≳ 10 are now thought to be key ingredients to explain the presence of the supermassive (109-10 M⊙) black holes in place <1 Gyr after the big bang. Once formed, massive seeds grow and emit copious amounts of radiation by accreting the left-over halo gas; their spectrum can then provide crucial information on their evolution. By combining radiation-hydrodynamic and spectral synthesis codes, we simulate the time-evolving spectrum emerging from the host halo of a MBH seed with initial mass 105 M⊙, assuming both standard Eddington-limited accretion, or slim accretion discs, appropriate for super-Eddington flows. The emission occurs predominantly in the observed infrared-submm (1-1000 μm) and X-ray (0.1-100 keV) bands. Such signal should be easily detectable by JWSTaround ˜ 1 μm up to z ˜ 25, and by ATHENA (between 0.1 and 10 keV, up to z ˜ 15). Ultra-deep X-ray surveys like the Chandra Deep Field South could have already detected these systems up to z ˜ 15. Based on this, we provide an upper limit for the z ≳ 6 MBH mass density of ρ• ≲ 2.5 × 102 M⊙ Mpc-3 assuming standard Eddington-limited accretion. If accretion occurs in the slim disc mode the limits are much weaker, ρ• ≲ 7.6 × 103 M⊙ Mpc-3 in the most constraining case.

Efficiency of seed production in southern pine seed orchards

Treesearch

David L. Bramlett

1977-01-01

Seed production in southern pine seed orchards can be evaluated by estimating the efficiency of four separate stages of cone, seed, and seedling development. Calculated values are: cone efficiency (CE), the ratio of mature cones to the initial flower crop; seed efficiency (SE), the ratio of filled seeds per cone to the seed potential; extraction efficiency (EE), the...

Probing disk wind and other properties of 4U 1630-47

NASA Astrophysics Data System (ADS)

Bhattacharyya, Sudip

2015-09-01

The accreting Galactic black hole transient 4U 1630-47, which is currently in outburst, is an ideal source to probe two types of accreted matter ejection: (1) via disk wind and (2) via jet, both using the observed narrow spectral lines (Diaz Trigo et al., 2013, Nature, 504, 206; Neilsen et al. 2014; Diaz Trigo et al. 2014). Chandra gratings are ideal to study such lines. The source also showed indications of high-frequency (HF) quasi-periodic oscillations (QPOs) in a rather high (150-450 Hz) frequency range, which can be extremely useful to probe the strong gravity regime. The AstroSat satellite, because of its large area and high timing resolution in a broad energy band, can potentially detect and measure HF QPOs and probe the source broadband spectrum and state. Hence, our proposed 30 ks Chandra exposure, nearly contemporaneous with complementary AstroSat observations, will provide an excellent way to probe the accretion and ejection mechanism in the strong gravity regime.

First detections of gravitational waves emitted from binary black hole mergers

NASA Astrophysics Data System (ADS)

Reitze, D. H.

2017-11-01

The LIGO Scientific Collaboration and the Virgo Collaboration carried out the inaugural ‘O1’ observing run from September 12, 2015 through January 19, 2016 using the newly commissioned Advanced LIGO interferometers located in Hanford,WAand Livingston, LA. During theO1 run and the O2 run currently underway, three definitive detections of gravitational waves have occurred, each produced during the mergers of binary stellar mass black holes. A fourth candidate gravitational-wave event was identified, also likely produced from a binary black hole merger. The detected gravitational waveforms allow for the inference of the intrinsic astrophysical parameters of the merging binary systems, as well as the resulting black hole produced by the mergers. The first detect detections of gravitational waves confirm the existence of binary black hole systems and have profound implications for astrophysics using gravitational waves as a new and powerful probe of the universe.

Impacts of fire on non-native plant recruitment in black spruce forests of interior Alaska.

PubMed

Walker, Xanthe J; Frey, Matthew D; Conway, Alexandra J; Jean, Mélanie; Johnstone, Jill F

2017-01-01

Climate change is expected to increase the extent and severity of wildfires throughout the boreal forest. Historically, black spruce (Picea mariana (Mill.) B.S.P.) forests in interior Alaska have been relatively free of non-native species, but the compounding effects of climate change and an altered fire regime could facilitate the expansion of non-native plants. We tested the effects of wildfire on non-native plant colonization by conducting a seeding experiment of non-native plants on different substrate types in a burned black spruce forest, and surveying for non-native plants in recently burned and mature black spruce forests. We found few non-native plants in burned or mature forests, despite their high roadside presence, although invasion of some burned sites by dandelion (Taraxacum officinale) indicated the potential for non-native plants to move into burned forest. Experimental germination rates were significantly higher on mineral soil compared to organic soil, indicating that severe fires that combust much of the organic layer could increase the potential for non-native plant colonization. We conclude that fire disturbances that remove the organic layer could facilitate the invasion of non-native plants providing there is a viable seed source and dispersal vector.

The antioxidant and radical scavenging activities of black pepper (Piper nigrum) seeds.

PubMed

Gülçin, Ilhami

2005-11-01

Water and ethanol crude extracts from black pepper (Piper nigrum) were investigated for their antioxidant and radical scavenging activities in six different assay, namely, total antioxidant activity, reducing power, 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. Both water extract (WEBP) and ethanol extract (EEBP) of black pepper exhibited strong total antioxidant activity. The 75 microg/ml concentration of WEBP and EEBP showed 95.5% and 93.3% inhibition on peroxidation of linoleic acid emulsion, respectively. On the other hand, at the same concentration, standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and alpha-tocopherol exhibited 92.1%, 95.0%, and 70.4% inhibition on peroxidation of linoleic acid emulsion, respectively. Also, total phenolic content in both WEBP and EEBP were determined as gallic acid equivalents. The total phenolics content of water and ethanol extracts were determined by the Folin-Ciocalteu procedure and 54.3 and 42.8 microg gallic acid equivalent of phenols was detected in 1 mg WEBP and EEBP.

The First Black Holes in the Cosmic Dark Ages

NASA Astrophysics Data System (ADS)

Pacucci, Fabio

2016-08-01

The main objective of the original work presented in this Thesis is to develop a theoretical framework to understand the growth, cosmological evolution and observational features of the first black holes, formed when the Universe was younger than ∼1 Gyr. In the first part a growth model is assembled, based on the developed radiation hydrodynamic code GEMS (Growth of Early Massive Seeds). We find that the accretion onto a Direct Collapse Black Hole (DCBH) of initial mass M_0=10^5 solar masses occurs at an average, super-Eddington, rate 0.1 solar masses per year (about 1.35 times the Eddington rate), is intermittent (duty-cycle ≤50%) and lasts ∼100 Myr, during which the black hole can accrete only up to ∼20% of the available mass. Our model identifies a "feeding-dominated" accretion regime for massive DCBHs (≥10^{5-6} solar masses) and a "feedback-limited" one for light ones (≤10^{3-4} solar masses), the latter being characterized by intermittent (duty cycles ≤0.5) and inefficient growth, with recurring outflow episodes. We have also explored slim disk models, appropriate for super-Eddington accretion, in which outflows play a negligible role and a black hole can accrete 80%-100% of the gas mass of the host halo in ∼10 Myr. We find that the differential growth of light and massive DCBH seeds leads to a bimodal cosmological evolution in mass. In the second part we investigate the observational properties of these sources. The time-evolving spectrum emerging from the host halo of a DCBH is analyzed: the emission occurs predominantly in the observed infrared-submm (1-1000 μm) and X-ray (0.1-100 keV) bands. Such signal should be easily detectable by the JWST at ∼1 μm, and by ATHENA (between 0.1 and 10 keV). Deep X-ray surveys like the CDF-S could have already detected these systems. Based on this, we provide upper limits for the z≥6z≥6 black hole mass density for both accretion models. A photometric method to identify DCBH candidates in deep multi

A role for seed storage proteins in Arabidopsis seed longevity

PubMed Central

Nguyen, Thu-Phuong; Cueff, Gwendal; Hegedus, Dwayne D; Rajjou, Loïc; Bentsink, Leónie

2015-01-01

Proteomics approaches have been a useful tool for determining the biological roles and functions of individual proteins and identifying the molecular mechanisms that govern seed germination, vigour and viability in response to ageing. In this work the dry seed proteome of four Arabidopsis thaliana genotypes, that carry introgression fragments at the position of seed longevity quantitative trait loci and as a result display different levels of seed longevity, was investigated. Seeds at two physiological states, after-ripened seeds that had the full germination ability and aged (stored) seeds of which the germination ability was severely reduced, were compared. Aged dry seed proteomes were markedly different from the after-ripened and reflected the seed longevity level of the four genotypes, despite the fact that dry seeds are metabolically quiescent. Results confirmed the role of antioxidant systems, notably vitamin E, and indicated that protection and maintenance of the translation machinery and energy pathways are essential for seed longevity. Moreover, a new role for seed storage proteins (SSPs) was identified in dry seeds during ageing. Cruciferins (CRUs) are the most abundant SSPs in Arabidopsis and seeds of a triple mutant for three CRU isoforms (crua crub cruc) were more sensitive to artificial ageing and their seed proteins were highly oxidized compared with wild-type seeds. These results confirm that oxidation is involved in seed deterioration and that SSPs buffer the seed from oxidative stress, thus protecting important proteins required for seed germination and seedling formation. PMID:26184996

Simple control of surface topography of gold nanoshells by a surfactant-less seeded-growth method.

PubMed

Topete, Antonio; Alatorre-Meda, Manuel; Villar-Álvarez, Eva M; Cambón, Adriana; Barbosa, Silvia; Taboada, Pablo; Mosquera, Víctor

2014-07-23

We report the synthesis of branched gold nanoshells (BGNS) through a seeded-growth surfactant-less method. This was achieved by decorating chitosan-Pluronic F127 stabilized poly(lactic-co-gycolic) acid nanoparticles (NPs) with Au seeds (NP-seed), using chitosan as an electrostatic self-assembling agent. Branched shells with different degrees of anisotropy and optical response were obtained by modulating the ratios of HAuCl4/K2CO3 growth solution, ascorbic acid (AA) and NP-seed precursor. Chitosan and AA were crucial in determining the BGNS size and structure, acting both as coreductants and structure directing growth agents. Preliminary cytotoxicity experiments point to the biocompatibility of the obtained BGNS, allowing their potential use in biomedical applications. In particular, these nanostructures with "hybrid" compositions, which combine the features of gold nanoshells and nanostars showed a better performance as surface enhanced Raman spectroscopy probes in detecting intracellular cell components than classical smoother nanoshells.

Use of pine nuts by grizzly and black bears in the Yellowstone area

USGS Publications Warehouse

Kendall, Katherine C.

1983-01-01

The large seeds (pine nuts) of whitebark pine are commonly eaten in the spring (March-May) and fall (September-November) by grizzly and black bears in Yellowstone National Park and adjacent areas (Craighead and Craighead 1972, Blanchard 1978, Mealey 1980) and western Montana (Tisch 1961; J. Sumner and J. J. Craighead, unpubl. rep., Montant Coop. Wildl. Res. Unit, Univ. Montana, Missoula, 1973). Similar nuts from limber pine are eaten by grizzly bears on the east Rocky Mountain Front of northwestern Montana (Schallenberger and Jonkel, annual rep., Border Grizzly Project, Univ. Montana, Missoula, 1980). The nuts of the European stone pine (P. cembra) are an important food for brown bears (U. arctos) throughout the taiga zone in the Soviet Union (Pavlov and Zhdanov 1972, Ustinov 1972, Yazan 1972). Both the production of whitebark pine cones (Forcella 1977, Blanchard 1978, Mealey 1980) and the quantity of nuts consumed by bears vary annually (Mealey 1975, Blancard 1978). Pine nuts are also an important food for red squirrels in whitebark forests. In fall, squirrels remove cones from trees and cache them in middens. Bears as well as other mammalian and avian seed predators compete with squirrels for whitebark nuts (Forcella 1977, Tomback 1977). Confusion about the ripening process of whitebark pine cones has resulted in errors in the literature on the availability of pine nuts as a bear food. Whitebark cones are indehiscent and do not disintegrate (Tomback 1981). Vertebrate foraging probably leaves few, if any, seed-bearing cones on trees by late fall; the cones remaining abscise sometime thereafter (Tomback 1981). Because cones do not abscise or release their seed in fall, bears may obtain pine nuts in 2 ways. Black bears may climb whitebark pine trees and break off cone-bearing brnahces to feed on cones (Tisch 1961, Mealey 1975, Forcella 1977); or both black bears and grizzly bears may raid squirrel caches to feed on pine nuts (Tisch 1961, Craighead and Craighead 1972

Enhanced nutraceutical potential of gamma irradiated black soybean extracts.

PubMed

Krishnan, Veda; Gothwal, Santosh; Dahuja, Anil; Vinutha, T; Singh, Bhupinder; Jolly, Monica; Praveen, Shelly; Sachdev, Archana

2018-04-15

Radiation processing of soybean, varying in seed coat colour, was carried out at dose levels of 0.25, 0.5 and 1 kGy to evaluate their potential anti-proliferative and cytoprotective effects in an in vitro cell culture system. Irradiated and control black (Kalitur) and yellow (DS9712) soybean extracts were characterized in terms of total phenolics, flavonoids and anthocyanins, especially cyanidin-3-glucoside (C3G). Using an epithelial cell line, BEAS-2B the potential cytoprotective effects of soybean extracts were evaluated in terms of intracellular ROS levels and cell viability. The most relevant scavenging effect was found in Kalitur, with 78% decrease in ROS, which well correlated with a 33% increase in C3G after a 1 kGy dose. Results evidenced a correspondence between in vitro antioxidant activity and a potential health property of black soybean extracts, exemplifying the nutraceutical role of C3G. To our knowledge this study is the first report validating the cytoprotective effects of irradiated black soybean extracts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Seed Polyphenolic Profile, Antioxidative Activity, and Fatty Acids Composition of Wild and Cultivated Carthamus Species.

PubMed

Karami, Soraya; Sabzalian, Mohammad R; Rahimmalek, Mehdi

2018-06-01

Total flavonoid content (TFC) and cyanidin-3-glucoside (Cyd-3-glu) of seed and seed coat extract of 16 genotypes from five species of Carthamus were studied, and their major polyphenolic compounds and antioxidant activity of the seed coat extracts were determined using HPLC analysis and DPPH assay, respectively. Additionally, fatty acids composition of the seed oil was analyzed by GC. In general, TFC and Cyd-3-glu content of seed coat extracts were higher than those of seed extracts. A novel breeding line with black seed coat (named A82) depicted lower TFC (3.79 mg QUE/g DW) but higher Cyd-3-glu (24.64 mg/g DW) compared to the white and other seed-pigmented genotypes. DPPH radical scavenging activity showed a strong association with Cyd-3-glu content (r = 0.84), but no correlation with TFC (r = -0.32). HPLC analysis of seed coat extracts revealed that four compounds were dominant constituents including rutin (7.23 - 117.95 mg/100 g DW), apigenin (4.37 - 64.88 mg/100 g DW), quercetin (3.09 - 14.10 mg/100 g DW), and ferulic acid (4.49 - 30.41 mg/100 g DW). Interestingly, the genotype A82 with an appropriate polyunsaturated/saturated fatty acids index (5.46%) and a moderate linoleic fatty acid content (64.70%) had higher nutritional and pharmaceutical value than all the other genotypes. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Density measurement in air with saturable absorbing seed gas

NASA Technical Reports Server (NTRS)

Baganoff, D.

1982-01-01

Approaches which have the potential to make density measurements in a compressible flow, where one or more laser beams are used as probes, were investigated. Saturation in sulfur hexafluoride iodine and a crossed beam technique where one beam acts as a saturating beam and the other is at low intensity and acts as a probe beam are considered. It is shown that a balance between an increase in fluorescence intensity with increasing pressure from line broadening and the normal decrease in intensity with increasing pressure from quenching can be used to develop a linear relation between fluorescence intensity and number density and lead to a new density measurement scheme. The method is used to obtain a density image of the cross section of an iodine seeded underexpanded supersonic jet of nitrogen, by illuminating the cross section by a sheet of laser light.

Resonance Raman Probes for Organelle-Specific Labeling in Live Cells

NASA Astrophysics Data System (ADS)

Kuzmin, Andrey N.; Pliss, Artem; Lim, Chang-Keun; Heo, Jeongyun; Kim, Sehoon; Rzhevskii, Alexander; Gu, Bobo; Yong, Ken-Tye; Wen, Shangchun; Prasad, Paras N.

2016-06-01

Raman microspectroscopy provides for high-resolution non-invasive molecular analysis of biological samples and has a breakthrough potential for dissection of cellular molecular composition at a single organelle level. However, the potential of Raman microspectroscopy can be fully realized only when novel types of molecular probes distinguishable in the Raman spectroscopy modality are developed for labeling of specific cellular domains to guide spectrochemical spatial imaging. Here we report on the design of a next generation Raman probe, based on BlackBerry Quencher 650 compound, which provides unprecedentedly high signal intensity through the Resonance Raman (RR) enhancement mechanism. Remarkably, RR enhancement occurs with low-toxic red light, which is close to maximum transparency in the biological optical window. The utility of proposed RR probes was validated for targeting lysosomes in live cultured cells, which enabled identification and subsequent monitoring of dynamic changes in this organelle by Raman imaging.

Probing the universality of synchronised hair around rotating black holes with Q-clouds

NASA Astrophysics Data System (ADS)

Herdeiro, Carlos; Kunz, Jutta; Radu, Eugen; Subagyo, Bintoro

2018-04-01

Recently, various families of black holes (BHs) with synchronised hair have been constructed. These are rotating BHs surrounded, as fully non-linear solutions of the appropriate Einstein-matter model, by a non-trivial bosonic field in synchronised rotation with the BH horizon. Some families bifurcate globally from a bald BH (e.g. the Kerr BH), whereas others bifurcate only locally from a bald BH (e.g. the D = 5 Myers-Perry BH). It would be desirable to understand how generically synchronisation allows hairy BHs to bifurcate from bald ones. However, the construction and scanning of the domain of existence of the former families of BHs can be a difficult and time consuming (numerical) task. Here, we first provide a simple perturbative argument to understand the generality of the synchronisation condition. Then, we observe that the study of Q-clouds is a generic tool to establish the existence of BHs with synchronised hair bifurcating (globally or locally) from a given bald BH without having to solve the fully non-linear coupled system of Einstein-matter equations. As examples, we apply this tool to establish the existence of synchronised hair around D = 6 Myers-Perry BHs, D = 5 black rings and D = 4 Kerr-AdS BHs, where D is the spacetime dimension. The black rings case provides an example of BHs with synchronised hair beyond spherical horizon topology, further establishing the generality of the mechanism.

Effects of photooxidation on membrane integrity in Salix nigra seeds

PubMed Central

Roqueiro, Gonzalo; Facorro, Graciela B.; Huarte, Mónica G.; Rubín de Celis, Emilio; García, Fernando; Maldonado, Sara; Maroder, Horacio

2010-01-01

Background and Aims Salix nigra seeds are desiccation-tolerant, as are orthodox seeds, although in contrast to other orthodox seeds they lose viability in a few weeks at room temperature. They also differ in that the chloroplasts of the embryo tissues conserve their chlorophyll and endomembranes. The aim of this paper was to investigate the role of chlorophyll in seed deterioration. Methods Seeds were aged at different light intensities and atmospheric conditions. Mean germination time and normal and total germination were evaluated. The formation of free radicals was assessed using electronic spin resonance spectroscopy, and changes in the fatty acid composition from phospholipids, galactolipids and triglycerides using gas–liquid chromatography. Membrane integrity was studied with electronic spin resonance spin probe techniques, electrolyte leakage and transmission electron microscopy. Key Results Light and oxygen played an important role in free-radical generation, causing a decrease in normal germination and an increase in mean germination time. Both indices were associated with a decrease in polyunsaturated fatty acids derived from membrane lipids as phospholipids and galactolipids. The detection of damage in thylakoid membranes and an increase in plasmalemma permeability were consistent with the decrease in both types of lipids. Triglycerides remained unchanged. Light-induced damage began in outermost tissues and spread inwards, decreasing normal germination. Conclusions Salix nigra seeds were very susceptible to photooxidation. The thylakoid membranes appeared to be the first target of the photooxidative process since there were large decreases in galactolipids and both these lipids and the activated chlorophyll are contiguous in the structure of that membrane. Changes in normal germination and mean germination time could be explained by the deteriorative effects of oxidation. PMID:20338949

Observing the shadow of Einstein-Maxwell-Dilaton-Axion black hole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Shao-Wen; Liu, Yu-Xiao, E-mail: weishw@lzu.edu.cn, E-mail: liuyx@lzu.edu.cn

In this paper, the shadows cast by Einstein-Maxwell-Dilaton-Axion black hole and naked singularity are studied. The shadow of a rotating black hole is found to be a dark zone covered by a deformed circle. For a fixed value of the spin a, the size of the shadow decreases with the dilaton parameter b. The distortion of the shadow monotonically increases with b and takes its maximal when the black hole approaches to the extremal case. Due to the optical properties, the area of the black hole shadow is supposed to equal to the high-energy absorption cross section. Based on thismore » assumption, the energy emission rate is investigated. For a naked singularity, the shadow has a dark arc and a dark spot or straight, and the corresponding observables are obtained. These results show that there is a significant effect of the spin a and dilaton parameter b on these shadows. Moreover, we examine the observables of the shadow cast by the supermassive black hole at the center of the Milky Way, which is very useful for us to probe the nature of the black hole through the astronomical observations in the near future.« less

The role of dung beetles as a secondary seed disperser after dispersal by frugivore mammals in a temperate deciduous forest

NASA Astrophysics Data System (ADS)

Koike, Shinsuke; Morimoto, Hideto; Kozakai, Chinatsu; Arimoto, Isao; Soga, Masashi; Yamazaki, Koji; Koganezawa, Masaaki

2012-05-01

We studied the effects of dung beetles on the fates of endozoochorous seeds of five species (Prunus jamasakura, Prunus verecunda, Prunus grayana, Swida controversa, and Vitis coignetiae) in a temperate deciduous forest in Japan during 2004-2006. In field experiments using dung of the Asiatic black bear (Ursus thibetanus), we investigated the depths that dung beetles (Onthophagus atripennis, Onthophagus lenzii, and Phelotrupes auratus) buried seeds (4.8-6.8 mm diameter) and plastic markers (2 or 5 mm diameter), the levels of predation on buried and unburied seeds, and germination rates of seeds buried to different depths. All three species buried the 2-mm markers, but only P. auratus buried the seeds and 5-mm markers. There were seasonal differences in mean seed burial rates (range, 27-51%) and depths (range, 1-27 mm). Significantly more seeds were buried in June, July, and September than in August or October, and the mean burial depth was significantly deeper in June and July. Most seeds and markers were buried to a 3-6 cm depth. Germination of seeds that were positioned at depths of 1-4 cm was significantly greater than that of seeds left on the surface or buried at greater depths. Buried seeds were less likely to disappear than seeds at the surface, which may reflect differential predation. These results suggested that dung beetles, especially P. auratus, acted as a secondary seed disperser that affected the survival and distribution of seeds dispersed by a frugivore.

Effect of seed sludge on characteristics and microbial community of aerobic granular sludge.

PubMed

Song, Zhiwei; Pan, Yuejun; Zhang, Kun; Ren, Nanqi; Wang, Aijie

2010-01-01

Aerobic granular sludge was cultivated by using different kinds of seed sludge in sequencing batch airlift reactor. The influence of seed sludge on physical and chemical properties of granular sludge was studied; the microbial community structure was probed by using scanning electron microscope and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that seed sludge played an important role on the formation of aerobic granules. Seed sludge taken from beer wastewater treatment plant (inoculum A) was more suitable for cultivating aerobic granules than that of sludge from municipal wastewater treatment plant (inoculum B). Cultivated with inoculum A, large amount of mature granules formed after 35 days operation, its SVI reached 32.75 mL/g, and SOUR of granular sludge was beyond 1.10 mg/(g x min). By contrast, it needed 56 days obtaining mature granules using inoculum B. DGGE profiles indicated that the dominant microbial species in mature granules were 18 and 11 OTU when inoculum A and B were respectively employed as seed sludge. The sequencing results suggested that dominant species in mature granules cultivated by inoculum A were Paracoccus sp., Devosia hwasunensi, Pseudoxanthomonas sp., while the dominant species were Lactococcus raffinolactis and Pseudomonas sp. in granules developed from inoculum B.

Pre-dispersal predation effect on seed packaging strategies and seed viability.

PubMed

DeSoto, Lucía; Tutor, David; Torices, Rubén; Rodríguez-Echeverría, Susana; Nabais, Cristina

2016-01-01

An increased understanding of intraspecific seed packaging (i.e. seed size/number strategy) variation across different environments may improve current knowledge of the ecological forces that drive seed evolution in plants. In particular, pre-dispersal seed predation may influence seed packaging strategies, triggering a reduction of the resources allocated to undamaged seeds within the preyed fruits. Assessing plant reactions to pre-dispersal seed predation is crucial to a better understanding of predation effects, but the response of plants to arthropod attacks remains unexplored. We have assessed the effect of cone predation on the size and viability of undamaged seeds in populations of Juniperus thurifera with contrasting seed packaging strategies, namely, North African populations with single-large-seeded cones and South European populations with multi-small-seeded cones. Our results show that the incidence of predation was lower on the single-large-seeded African cones than on the multi-small-seeded European ones. Seeds from non-preyed cones were also larger and had a higher germination success than uneaten seeds from preyed cones, but only in populations with multi-seeded cones and in cones attacked by Trisetacus sp., suggesting a differential plastic response to predation. It is possible that pre-dispersal seed predation has been a strong selective pressure in European populations with high cone predation rates, being a process which maintains multi-small-seeded cones and empty seeds as a strategy to save some seeds from predation. Conversely, pre-dispersal predation might not have a strong effect in the African populations with single-large-seeded cones characterized by seed germination and filling rates higher than those in the European populations. Our results indicate that differences in pre-dispersal seed predators and predation levels may affect both selection on and intraspecific variation in seed packaging.

A polysaccharide fraction of adlay seed (Coixlachryma-jobi L.) induces apoptosis in human non-small cell lung cancer A549 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Xiangyi; Liu, Wei; Wu, Junhua

Highlights: Black-Right-Pointing-Pointer A polysaccharide from adlay seed, its molecular mass, optical rotation and sugars was determined. Black-Right-Pointing-Pointer We demonstrated that a polysaccharide from adlay can induce apoptosis in cancer cells. Black-Right-Pointing-Pointer The polysaccharide inhibited the metabolism and proliferation of NSCLC A549 cells. Black-Right-Pointing-Pointer The polysaccharide may trigger apoptosis via the mitochondria-dependent pathway. -- Abstract: Different seed extracts from Coix lachryma-jobi (adlay seed) have been used for the treatment of various cancers in China, and clinical data support the use of these extracts for cancer therapy; however, their underlying molecular mechanisms have not been well defined. A polysaccharide fraction, designated asmore » CP-1, was extracted from the C.lachryma-jobi L. var. using the ethanol subsiding method. CP-1 induced apoptosis in A549 cells in a dose-dependent manner, as determined by MTT assay. Apoptotic bodies were observed in the cells by scanning electronic microscopy. Apoptosis and DNA accumulation during S-phase of the cell cycle were determined by annexin V-FITC and PI staining, respectively, and measured by flow cytometry. CP-1 also extended the comet tail length on single cell gel electrophoresis, and disrupted the mitochondrial membrane potential. Further analysis by western blotting showed that the expression of caspase-3 and caspase-9 proteins was increased. Taken together, our results demonstrate that CP-1 is capable of inhibiting A549 cell proliferation and inducing apoptosis via a mechanism primarily involving the activation of the intrinsic mitochondrial pathway. The assay data suggest that in addition to its nutritional properties, CP-1 is a very promising candidate polysaccharide for the development of anti-cancer medicines.« less

Development of the Seeding System Used for Laser Velocimeter Surveys of the NASA Low-Speed Centrifugal Compressor Flow Field

NASA Technical Reports Server (NTRS)

Wasserbauer, C. A.; Hathaway, M. D.

1994-01-01

Consideration is given to an atomizer-based system for distributing high-volume rates of polystyrene latex (PSL) seed material developed to support laser velocimeter investigations of the NASA Low-Speed Compressor flow field. Complete evaporation of the liquid carrier before the flow entering the compressor was of primary concern for the seeder system design. It is argued that the seed nozzle should incorporate a needle valve that can mechanically dislodge accumulated PSL seed material when the nozzle is turned off. Water is less expensive as the liquid carrier and should be used whenever adequate residence times are available to ensure complete evaporation. PSL agglomerates over time and needs to be mixed or blended before use. Arrangement of the spray nozzles needs to be adjustable to provide maximum seeding at the laser probe volume.

Limitations of the commonly used simplified laterally uniform optical fiber probe-tissue interface in Monte Carlo simulations of diffuse reflectance

PubMed Central

Naglič, Peter; Pernuš, Franjo; Likar, Boštjan; Bürmen, Miran

2015-01-01

Light propagation models often simplify the interface between the optical fiber probe tip and tissue to a laterally uniform boundary with mismatched refractive indices. Such simplification neglects the precise optical properties of the commonly used probe tip materials, e.g. stainless steel or black epoxy. In this paper, we investigate the limitations of the laterally uniform probe-tissue interface in Monte Carlo simulations of diffuse reflectance. In comparison to a realistic probe-tissue interface that accounts for the layout and properties of the probe tip materials, the simplified laterally uniform interface is shown to introduce significant errors into the simulated diffuse reflectance. PMID:26504647

The polyphenol-rich extracts from black chokeberry and grape seeds impair changes in the platelet adhesion and aggregation induced by a model of hyperhomocysteinemia.

PubMed

Malinowska, Joanna; Oleszek, Wieslaw; Stochmal, Anna; Olas, Beata

2013-04-01

The mechanism action of the polyphenol-rich extracts from berries of Aronia melanocarpa (black chokeberry) and from grape seeds in the defence against homocysteine (Hcy) and its derivatives action in blood platelets is still unknown. In this study, the influence of the aronia extract and grape seeds extract (GSE) on the platelet adhesion to collagen and fibrinogen and the platelet aggregation during a model of hyperhomocysteinemia was investigated. The aim of our study in vitro was also to investigate superoxide anion radicals (O₂⁻•) production after incubation of platelets with Hcy, HTL and the aronia extract and GSE during a model of hyperhomocysteinemia (induced by reduced form of homocysteine at final dose of 100 μM) and the most reactive form of Hcy--its cyclic thioester, homocysteine thiolactone (HTL, 1 μM). Moreover, the additional aim of our study was also to establish and compare the influence of the aronia extract, GSE and resveratrol (3,4',5-trihydroxystilben), a phenolic compound, which has been supposed to be beneficial for the prevention of cardiovascular events, on selected steps of platelet activation. The effects of tested extracts on adhesion of blood platelets to collagen and fibrinogen were determined according to Tuszynski and Murphy. The platelet aggregation was determined by turbidimetry method using a Chrono-log Lumi-aggregometer. We have observed that HTL, like its precursor-Hcy stimulated the generation of O₂⁻• (measured by the superoxide dismutase-inhibitable reduction of cytochrome c) in platelets and caused an augmentation of the platelet adhesion and aggregation induced by the strong physiological agonist-thrombin. Our present results in vitro also demonstrated that the aronia extract and grape seeds extract reduced the toxicity action of Hcy and HTL on blood platelet adhesion to collagen and fibrinogen, the platelet aggregation and superoxide anion radicals production in platelets, suggesting its potential protective

Dehydration-Induced Redistribution of Amphiphilic Molecules between Cytoplasm and Lipids Is Associated with Desiccation Tolerance in Seeds1

PubMed Central

Buitink, Julia; Leprince, Olivier; Hoekstra, Folkert A.

2000-01-01

This study establishes a relationship between desiccation tolerance and the transfer of amphiphilic molecules from the cytoplasm into lipids during drying, using electron paramagnetic resonance spectroscopy of amphiphilic spin probes introduced into imbibed radicles of pea (Pisum sativum) and cucumber (Cucumis sativa) seeds. Survival following drying and a membrane integrity assay indicated that desiccation tolerance was present during early imbibition and lost in germinated radicles. In germinated cucumber radicles, desiccation tolerance could be re-induced by an incubation in polyethylene glycol (PEG) before drying. In desiccation-intolerant radicles, partitioning of spin probes into lipids during dehydration occurred at higher water contents compared with tolerant and PEG-induced tolerant radicles. The difference in partitioning behavior between desiccation-tolerant and -intolerant tissues could not be explained by the loss of water. Consequently, using a two-phase model system composed of sunflower or cucumber oil and water, physical properties of the aqueous solvent that may affect the partitioning of amphiphilic spin probes were investigated. A significant relationship was found between the partitioning of spin probes and the viscosity of the aqueous solvent. Moreover, in desiccation-sensitive radicles, the rise in cellular microviscosity during drying commenced at higher water contents compared with tolerant or PEG-induced tolerant radicles, suggesting that the microviscosity of the cytoplasm may control the partitioning behavior in dehydrating seeds. PMID:11080316

Feeding ecology of Merriam's turkeys (Meleagris gallopavo merriami) in the Black Hills, South Dakota

Treesearch

Mark A. Rumble; Stanley H. Anderson

1996-01-01

W e studied the feeding ecology of Merriam’s turkey (Meleagris gallopavo merriami) in the Black Hills, South Dakota, between 1986 and 1989. Adult birds consumed 78 kinds of food, of which four food categories constituted >79% of winter diets and six food categories constituted >75% of summer diets. Ponderosa pine (Pinus ponderosa) seeds were...

An actively accreting massive black hole in the dwarf starburst galaxy Henize 2-10.

PubMed

Reines, Amy E; Sivakoff, Gregory R; Johnson, Kelsey E; Brogan, Crystal L

2011-02-03

Supermassive black holes are now thought to lie at the heart of every giant galaxy with a spheroidal component, including our own Milky Way. The birth and growth of the first 'seed' black holes in the earlier Universe, however, is observationally unconstrained and we are only beginning to piece together a scenario for their subsequent evolution. Here we report that the nearby dwarf starburst galaxy Henize 2-10 (refs 5 and 6) contains a compact radio source at the dynamical centre of the galaxy that is spatially coincident with a hard X-ray source. From these observations, we conclude that Henize 2-10 harbours an actively accreting central black hole with a mass of approximately one million solar masses. This nearby dwarf galaxy, simultaneously hosting a massive black hole and an extreme burst of star formation, is analogous in many ways to galaxies in the infant Universe during the early stages of black-hole growth and galaxy mass assembly. Our results confirm that nearby star-forming dwarf galaxies can indeed form massive black holes, and that by implication so can their primordial counterparts. Moreover, the lack of a substantial spheroidal component in Henize 2-10 indicates that supermassive black-hole growth may precede the build-up of galaxy spheroids.

Direct formation of supermassive black holes via multi-scale gas inflows in galaxy mergers.

PubMed

Mayer, L; Kazantzidis, S; Escala, A; Callegari, S

2010-08-26

Observations of distant quasars indicate that supermassive black holes of billions of solar masses already existed less than a billion years after the Big Bang. Models in which the 'seeds' of such black holes form by the collapse of primordial metal-free stars cannot explain the rapid appearance of these supermassive black holes because gas accretion is not sufficiently efficient. Alternatively, these black holes may form by direct collapse of gas within isolated protogalaxies, but current models require idealized conditions, such as metal-free gas, to prevent cooling and star formation from consuming the gas reservoir. Here we report simulations showing that mergers between massive protogalaxies naturally produce the conditions for direct collapse into a supermassive black hole with no need to suppress cooling and star formation. Merger-driven gas inflows give rise to an unstable, massive nuclear gas disk of a few billion solar masses, which funnels more than 10(8) solar masses of gas to a sub-parsec-scale gas cloud in only 100,000 years. The cloud undergoes gravitational collapse, which eventually leads to the formation of a massive black hole. The black hole can subsequently grow to a billion solar masses on timescales of about 10(8) years by accreting gas from the surrounding disk.

Preliminary studies on allelopatic effect of some woody plants on seed germination of rye-grass and tall fescue.

PubMed

Arouiee, H; Nazdar, T; Mousavi, A

2010-11-01

In order to investigation of allelopathic effects of some ornamental trees on seed germination of rye-grass (Lolium prenne) and tall fescue (Festuca arundinaceae), this experiment was conducted in a randomized complete block design with 3 replicates at the laboratory of Horticultural Sciences Department of Ferdowsi University of Mashhad, during 2008. In this research, we studied the effect of aqueous and hydro-alcoholic extracts of Afghanistan pine (Pinus eldarica), arizona cypress (Cupressus arizonica), black locust (Robinia psedue acacia) and box elder (Acer negundo) leaves that prepared in 1:5 ratio on seed germination percent and rate for two grasses. The results showed that all extracts decreased statistically seed germination in compared to control treatment. The highest germination percentage and germination rate of tested grass detected in control treatment. Hydro-alcoholic extracts of all woody plants (15, 30%) were completely inhibited seed germination of rye-grass and tall fescue. Also aqueous extract of arizona cypress was completely inhibited seed germination of tall fescue and had more inhibitory activity than other aqueous extracts on rye-grass. Between aqueous extracts, the highest and lowest seed germination of rye-grass was found in Afghanistan pine and arizona cypress, respectively.

Seed dispersal and seed fate in Joshua tree (Yucca brevifolia)

USGS Publications Warehouse

Waitman, B.A.; Vander Wall, S.B.; Esque, Todd

2012-01-01

Joshua tree (Yucca brevifolia) is a charismatic symbol of the Mojave Desert. Despite its familiarity, we know little about the reproduction of this species, including mechanisms of seed dispersal. Here we examine mechanisms of seed dispersal and resulting seed fate. We experimentally tracked fruit and seed removal and followed the fates of Joshua tree seeds using radioactive tracers. The majority of Joshua tree fruits monitored were taken directly from the tree canopy by white-tailed antelope squirrels, and seeds and fruits on the soil surface were quickly removed by animals. Rodents given seeds labeled with scandium-46 cached them between 0.1 cm and 4.1 cm deep. Seedling emergence was most common for seeds planted 1 cm deep, whereas seeds placed on the soil surface seldom germinated. Wind dispersal is unlikely because fruits and seeds lack adaptations for wind dispersal; wind speeds required to move Joshua tree seeds and fruits across the soil surface were higher than those typically found in the Mojave Desert. Further, rodents removed most seeds before abiotic burial was possible. We conclude that most Joshua tree seeds are dispersed by scatter hoarding by rodents, and that caches made by rodents are suitable sites for seedling emergence.

Gamma Ray Bursts as Cosmological Probes with EXIST

NASA Astrophysics Data System (ADS)

Hartmann, Dieter; EXIST Team

2006-12-01

The EXIST mission, studied as a Black Hole Finder Probe within NASA's Beyond Einstein Program, would, in its current design, trigger on 1000 Gamma Ray Bursts (GRBs) per year (Grindlay et al, this meeting). The redshift distribution of these GRBs, using results from Swift as a guide, would probe the z > 7 epoch at an event rate of > 50 per year. These bursts trace early cosmic star formation history, point to a first generation of stellar objects that reionize the universe, and provide bright beacons for absorption line studies with groundand space-based observatories. We discuss how EXIST, in conjunction with other space missions and future large survey programs such as LSST, can be utilized to advance our understanding of cosmic chemical evolution, the structure and evolution of the baryonic cosmic web, and the formation of stars in low metallicity environments.

Thioredoxin-Linked Proteins Are Reduced during Germination of Medicago truncatula Seeds1[W][OA

PubMed Central

Alkhalfioui, Fatima; Renard, Michelle; Vensel, William H.; Wong, Joshua; Tanaka, Charlene K.; Hurkman, William J.; Buchanan, Bob B.; Montrichard, Françoise

2007-01-01

Germination of cereals is accompanied by extensive change in the redox state of seed proteins. Proteins present in oxidized form in dry seeds are converted to the reduced state following imbibition. Thioredoxin (Trx) appears to play a role in this transition in cereals. It is not known, however, whether Trx-linked redox changes are restricted to cereals or whether they take place more broadly in germinating seeds. To gain information on this point, we have investigated a model legume, Medicago truncatula. Two complementary gel-based proteomic approaches were followed to identify Trx targets in seeds: Proteins were (1) labeled with a thiol-specific probe, monobromobimane (mBBr), following in vitro reduction by an NADP/Trx system, or (2) isolated on a mutant Trx affinity column. Altogether, 111 Trx-linked proteins were identified with few differences between axes and cotyledons. Fifty nine were new, 34 found previously in cereal or peanut seeds, and 18 in other plants or photosynthetic organisms. In parallel, the redox state of proteins assessed in germinating seeds using mBBr revealed that a substantial number of proteins that are oxidized or partly reduced in dry seeds became more reduced upon germination. The patterns were similar for proteins reduced in vivo during germination or in vitro by Trx. In contrast, glutathione and glutaredoxin were less effective as reductants in vitro. Overall, more than half of the potential targets identified with the mBBr labeling procedure were reduced during germination. The results provide evidence that Trx functions in the germination of seeds of dicotyledons as well as monocotyledons. PMID:17513483

An Accretion Model for the Growth of Black Hole in Quasars

NASA Technical Reports Server (NTRS)

Lu, Ye; Cheng, K. S.; Zhang, S. N.

2003-01-01

A possible accretion model associated with the ionization instability of quasar disks is proposed to address the growth of the central black hole harbored in the host galaxy. The evolution of quasars in cosmic time is assumed to change from a highly active state to a quiescent state triggered by the S-shaped ionization instability of the quasar accretion disk. For a given external mass transfer rate ionization instability can modify accretion rate in the disk and separates the accretion flows of the disk into three different phases like a S-shape. We suggest that the bright quasars observed today are those quasars with disks in the upper branch of S-shaped instability and the dormant quasars are the system in the lower branch. The disk is assumed to evolve as ADIOS configuration in the lower branch. The mass ratio between black hole and its host galactic bulge is a nature consequence of ADIOS. Our model also demonstrates that a seed black hole 2 x 10(exp 6) solar masses similar to those found in spiral galaxies today is needed to produce a black hole with a final mass 2 x 10(exp 8) solar masses.

Seed-feeding insects impacting globemallow seed production

Treesearch

Robert Hammon; Melissa Franklin

2012-01-01

Weevils (Anthonomus sphaeralciae Fall [Coleoptera: Curculionidae]), which attack flowers and developing seeds, can significantly impact globemallow Sphaeralcea spp. A. St.-Hil. (Malvaceae) seed production without a grower even noticing there was insect damage. This weevil damaged almost one-quarter of the flowers in a seed production field in Delta County, Colorado,...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

Collapse of primordial gas clouds and the formation of quasar black holes

NASA Technical Reports Server (NTRS)

Loeb, Abraham; Rasio, Frederic A.

1994-01-01

The formation of quasar black holes during the hydrodynamic collapse of protogalactic gas clouds is discussed. The dissipational collapse and long-term dynamical evolution of these systems is analyzed using three-dimensional numerical simulations. The calculations focus on the final collapse stages of the inner baryonic component and therefore ignore the presence of dark matter. Two types of initial conditions are considered: uniformly rotating spherical clouds, and iirotational ellipsoidal clouds. In both cases the clouds are initially cold, homogeneous, and not far from rotational support (T/(absolute value of W) approximately equals 0.1). Although the details of the dynamical evolution depend sensitively on the initial conditions, the qualitative features of the final configurations do not. Most of the gas is found to fragment into small dense clumps, that eventually make up a spheroidal component resembling a galactic bulge. About 5% of the initial mass remains in the form of a smooth disk of gas supported by rotation in the gravitational potential potential well of the outer spheroid. If a central seed black hole of mass approximately greater than 10(exp 6) solar mass forms, it can grow by steady accretion from the disk and reach a typical quasar black hole mass approximately 10(exp 8) solar mass in less than 5 x 10(exp 8) yr. In the absence of a sufficiently massive seed, dynamical instabilities in a strongly self-gravitating inner region of the disk will inhibit steady accretion of gas and may prevent the immediate formation of quasar.

Magnetized Mini-Disk Simulations about Binary Black Holes

NASA Astrophysics Data System (ADS)

Noble, Scott; Bowen, Dennis B.; d'Ascoli, Stephane; Mewes, Vassilios; Campanelli, Manuela; Krolik, Julian

2018-01-01

Accretion disks around supermassive binary black holes offer a rare opportunity to probe the strong-field limit of dynamical gravity by using the ambient matter as a lighthouse. Accurate simulations of these systems using a variety of configurations will be critical to interpreting future observations of them. We have performed the first 3-d general relativistic magnetohydrodynamic simulations of mini-disks about a pair of equal mass black holes in the inspiral regime of their orbit. In this talk, we will present our latest results of 3-d general relativistic magnetohydrodynamic supercomputer simulations of accreting binary black holes during the post-Newtonian inspiral phase of their evolution. The goal of our work is to explore whether these systems provide a unique means to identify and characterize them with electromagnetic observations. We will provide a brief summary of the known electromagnetic signatures, in particular spectra and images obtained from post-process ray-tracing calculations of our simulation data. We will also provide a context for our results and describe our future avenues of exploration.

Biotechnology Information on Prices of Genetically Modified Seeds in the United States and Argentina

DTIC Science & Technology

2000-01-01

12-$15 Sources: GAO based its estimates on data from Doane Marketing Research , Inc., and Argentine industry sources. 8See app. I for details on...Doane Marketing Research , Inc., and Argentine industry sources. Issues Related to Our Price Comparisons For added perspective in interpreting the...on data from Doane Marketing Research , Inc., and other industry sources. The black market for hybrid corn seed is negligible. Hybrid corn is

Shining Light on Quantum Gravity with Pulsar-Black hole Binaries

NASA Astrophysics Data System (ADS)

Estes, John; Kavic, Michael; Lippert, Matthew; Simonetti, John H.

2017-03-01

Pulsars are some of the most accurate clocks found in nature, while black holes offer a unique arena for the study of quantum gravity. As such, pulsar-black hole (PSR-BH) binaries provide ideal astrophysical systems for detecting the effects of quantum gravity. With the success of aLIGO and the advent of instruments like SKA and eLISA, the prospects for the discovery of such PSR-BH binaries are very promising. We argue that PSR-BH binaries can serve as ready-made testing grounds for proposed resolutions to the black hole information paradox. We propose using timing signals from a pulsar beam passing through the region near a black hole event horizon as a probe of quantum gravitational effects. In particular, we demonstrate that fluctuations of the geometry outside a black hole lead to an increase in the measured root mean square deviation of the arrival times of pulsar pulses traveling near the horizon. This allows for a clear observational test of the nonviolent nonlocality proposal for black hole information escape. For a series of pulses traversing the near-horizon region, this model predicts an rms in pulse arrival times of ˜ 30 μ {{s}} for a 3{M}⊙ black hole, ˜ 0.3 {ms} for a 30{M}⊙ black hole, and ˜ 40 {{s}} for Sgr A*. The current precision of pulse time-of-arrival measurements is sufficient to discern these rms fluctuations. This work is intended to motivate observational searches for PSR-BH systems as a means of testing models of quantum gravity.

Black English and Black Attitudes

ERIC Educational Resources Information Center

Shores, David L.

1974-01-01

Examines attitudes in the Black community towards the topic of Black English and specifically the controversy about the relationship of the speech of Blacks to that of Whites, the distinctive features in the speaking and writing of Black college students, and the attitudes of Black educators. Available from South Atlantic Modern Language…

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds.

PubMed

Gorim, Linda; Asch, Folkard

2017-05-24

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition.

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds

PubMed Central

Gorim, Linda; Asch, Folkard

2017-01-01

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition. PMID:28538658

‘Spotted Nanoflowers’: Gold-seeded Zinc Oxide Nanohybrid for Selective Bio-capture

NASA Astrophysics Data System (ADS)

Perumal, Veeradasan; Hashim, U.; Gopinath, Subash C. B.; Haarindraprasad, R.; Foo, K. L.; Balakrishnan, S. R.; Poopalan, P.

2015-07-01

Hybrid gold nanostructures seeded into nanotextured zinc oxide (ZnO) nanoflowers (NFs) were created for novel biosensing applications. The selected ‘spotted NFs’ had a 30-nm-thick gold nanoparticle (AuNP) layer, chosen from a range of AuNP thicknesses, sputtered onto the surface. The generated nanohybrids, characterized by morphological, physical and structural analyses, were uniformly AuNP-seeded onto the ZnO NFs with an average length of 2-3 μm. Selective capture of molecular probes onto the seeded AuNPs was evidence for the specific interaction with DNA from pathogenic Leptospirosis-causing strains via hybridization and mis-match analyses. The attained detection limit was 100 fM as determined via impedance spectroscopy. High levels of stability, reproducibility and regeneration of the sensor were obtained. Selective DNA immobilization and hybridization were confirmed by nitrogen and phosphorus peaks in an X-ray photoelectron spectroscopy analysis. The created nanostructure hybrids illuminate the mechanism of generating multiple-target, high-performance detection on a single NF platform, which opens a new avenue for array-based medical diagnostics.

'Black universe' epoch in string cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchel, Alex; Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2J 2W9; Kofman, Lev

2008-10-15

String theory compactification involves manifolds with multiple warp factors. For cosmological applications, we often introduce a short, high-energy inflationary throat, and a long, low-energy standard model (SM) throat. It is assumed that at the end of inflation, the excited Kaluza-Klein modes from the inflationary throat tunnel to the SM throat and reheat standard model degrees of freedom, which are attached to probe brane(s). However, the huge hierarchy of energy scales can result in a highly dynamic transition of the throat geometry. We point out that in such a cosmological scenario the standard model throat (together with SM brane) will bemore » cloaked by a Schwarzschild horizon, produced by the Kaluza-Klein modes tunneling from the short throat. The black brane formation is dual to the first order chiral phase transition of the cascading gauge theory. We calculate the critical energy density corresponding the formation of the black hole (BH) horizon in the long throat. We discuss the duality between 'black universe' cosmology and an expanding universe driven by the hot gauge theory radiation. We address the new problem of the hierarchical multiple-throat scenarios: SM brane disappearance after the decay of the BH horizon.« less

[Dynamics of seed rain of Tripterygium hypoglaucum and soil seed bank].

PubMed

Zhang, Zhi-Wei; Wei, Yong-Sheng; Liu, Xiang; Su, Shu; Qu, Xian-You; Wang, Chang-Hua

2017-11-01

Tripterygium hypoglaucum is an endangered species in arid areas of Xiannvshan Chongqing, China. The dynamic characteristics of seed rain and soil seed bank of T. hypoglaucum were studied in this paper．Results showed that T. hypoglaucum years of mature seeds distribution number up to October; the seed rain occurred from the last ten-day of September to in the first ten-day of November and the peak of scattered seed rain concentrated in the October．The numbers of soil seed bank at 2-5 cm soil layer,mainly concentrated in the 1.5-3.5 m range. T. hypoglaucum seeds to the wind as a force for transmission, the transmission ability is strong, but in the process of natural reproduction, full mature seed rate is low, the soil seed bank seeds seed short-lived factors these were unfavorable for the natural reproduction of T. hypoglaucum population. Copyright© by the Chinese Pharmaceutical Association.

[Procedure of seed quality testing and seed grading standard of Prunus humilis].

PubMed

Wen, Hao; Ren, Guang-Xi; Gao, Ya; Luo, Jun; Liu, Chun-Sheng; Li, Wei-Dong

2014-11-01

So far there exists no corresponding quality test procedures and grading standards for the seed of Prunus humilis, which is one of the important source of base of semen pruni. Therefor we set up test procedures that are adapt to characteristics of the P. humilis seed through the study of the test of sampling, seed purity, thousand-grain weight, seed moisture, seed viability and germination percentage. 50 cases of seed specimens of P. humilis tested. The related data were analyzed by cluster analysis. Through this research, the seed quality test procedure was developed, and the seed quality grading standard was formulated. The seed quality of each grade should meet the following requirements: for first grade seeds, germination percentage ≥ 68%, thousand-grain weight 383 g, purity ≥ 93%, seed moisture ≤ 5%; for second grade seeds, germination percentage ≥ 26%, thousand-grain weight ≥ 266 g, purity ≥ 73%, seed moisture ≤9%; for third grade seeds, germination percentage ≥ 10%, purity ≥ 50%, thousand-grain weight ≥ 08 g, seed moisture ≤ 13%.

Effect of Seed Density on Splash Cup Seed Dispersal

NASA Astrophysics Data System (ADS)

Wigger, Patrick; Pepper, Rachel

2017-11-01

Splash cup plants are plants that utilize a small, mm-sized cup filled with seeds as a method of seed dispersal. The cup uses kinetic energy of an incident raindrop in order to project the seeds away from the plant up to 1 meter. The dispersal distance is important to ensure the offspring are not clustered too tightly to the parent plant. It has previously been found that a cup angle of 40 degrees to the horizontal is optimal for maximum dispersal of water from cups with no seeds. In this study we examine if the 40 degree cup is optimal for cups containing seeds with varying densities. We released uniform water drops above 5.0 mm 3D printed models of splash cups, using 1.0 mm plastic and glass microspheres of varying densities to simulate seeds. We observed the dispersal characteristics of each bead type by measuring the final seed locations after each splash, and by recording high speed video to determine the angle and velocity of the seeds as they exited the cup.

New Worlds / New Horizons Science with an X-ray Astrophysics Probe

NASA Technical Reports Server (NTRS)

Smith, Randall K.; Bookbinder, Jay A.; Hornschemeier, Ann E.; Bandler, Simon; Brandt, W. N.; Hughes, John P.; McCammon, Dan; Matsumoto, Hironori; Mushotzky, Richard; Osten, Rachel A.;

Gaussian interferometric power and Black box estimation of Unruh temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jieci, E-mail: jcwang@hunnu.edu.cn; Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190; Cao, Haixin

2016-10-15

We present a black box estimation paradigm of Unruh temperature in a relativistic bosonic continuous-variable setting. It is shown that the guaranteed precision for the estimation of Unruh temperature can be evaluated by the Gaussian interferometric power for a given probe state. We demonstrate that the amount of interferometric power is always beyond the entanglement type quantum correlations in a relativistic setting. It is found that due to the fact that Unruh radiation acts as a thermal bath on the probe system, it destroys available resources of the probe system and reduces the guaranteed precision of the estimation of Unruhmore » temperature. We also find that the thermal noise induced by Unruh effect will generate interferometric power between accelerated Bob and his auxiliary partner anti-Bob, while it does not generate any correlation between inertial Alice and anti-Bob.« less

Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents

USGS Publications Warehouse

Vander Wall, S.B.; Esque, T.; Haines, D.; Garnett, M.; Waitman, B.A.

2006-01-01

Joshua tree (Yucca brevifolia) is a distinctive and charismatic plant of the Mojave Desert. Although floral biology and seed production of Joshua tree and other yuccas are well understood, the fate of Joshua tree seeds has never been studied. We tested the hypothesis that Joshua tree seeds are dispersed by seed-caching rodents. We radioactively labelled Joshua tree seeds and followed their fates at five source plants in Potosi Wash, Clark County, Nevada, USA. Rodents made a mean of 30.6 caches, usually within 30 m of the base of source plants. Caches contained a mean of 5.2 seeds buried 3-30 nun deep. A variety of rodent species appears to have prepared the caches. Three of the 836 Joshua tree seeds (0.4%) cached germinated the following spring. Seed germination using rodent exclosures was nearly 15%. More than 82% of seeds in open plots were removed by granivores, and neither microsite nor supplemental water significantly affected germination. Joshua tree produces seeds in indehiscent pods or capsules, which rodents dismantle to harvest seeds. Because there is no other known means of seed dispersal, it is possible that the Joshua tree-rodent seed dispersal interaction is an obligate mutualism for the plant.

On the gravitational wave background from black hole binaries after the first LIGO detections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cholis, Ilias, E-mail: icholis1@jhu.edu

The detection of gravitational waves from the merger of binary black holes by the LIGO Collaboration has opened a new window to astrophysics. With the sensitivities of ground based detectors in the coming years, we will principally detect local binary black hole mergers. The integrated merger rate can instead be probed by the gravitational-wave background, the incoherent superposition of the released energy in gravitational waves during binary-black-hole coalescence. Through that, the properties of the binary black holes can be studied. In this work we show that by measuring the energy density Ω{sub GW} (in units of the cosmic critical density)more » of the gravitational-wave background, we can search for the rare ∼ 100 M {sub ⊙} massive black holes formed in the Universe. In addition, we can answer how often the least massive BHs of mass ≳ 3 M {sub ⊙} form. Finally, if there are multiple channels for the formation of binary black holes and if any of them predicts a narrow mass range for the black holes, then the total Ω{sub GW} spectrum may have features that with the future Einstein Telescope can be detected.« less

Direct seeding

Treesearch

Richard M. Godman; G. A. Mattson

1992-01-01

At present, direct seeding of hardwoods in the Lake States is more of a supplemental than a primary means of artificial regeneration. Direct seeding may be used to augment a poor seed crop or increase the proportion of a preferred species. In the future, it will no doubt play a bigger role-in anticipation of this we need to collect and store the amounts of seed needed...

Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

USGS Publications Warehouse

Du, X.; Guo, Q.; Gao, X.; Ma, K.

2007-01-01

Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms. We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan, southwestern China. The results showed that: (1) there were marked differences in (mature) seed production between mast (733,700 seeds in 2001) and regular (51,200 and 195,600 seeds in 2002 and 2003, respectively) years for C. fargesii. (2) Most seeds were dispersed in leaf litter, humus and 0-2 cm depth soil in seed bank. (3) Frequency distributions of both DBH and height indicated that C. fargesii had a relatively stable population. (4) Seed rain, seed ground density, seed loss, and leaf fall were highly dynamic and certain quantity of seeds were preserved on the ground for a prolonged time due to predator satiation in both the mast and regular years so that the continuous presence of seed bank and seedling recruitments in situ became possible. Both longer time observations and manipulative experiments should be carried out to better understand the roles of seed dispersal and regeneration process in the ecosystem performance. ?? 2006 Elsevier B.V. All rights reserved.

CACTA-superfamily transposable element is inserted in MYB transcription factor gene of soybean line producing variegated seeds.

PubMed

Yan, Fan; Di, Shaokang; Takahashi, Ryoji

2015-08-01

The R gene of soybean, presumably encoding a MYB transcription factor, controls seed coat color. The gene consists of multiple alleles, R (black), r-m (black spots and (or) concentric streaks on brown seed), and r (brown seed). This study was conducted to determine the structure of the MYB transcription factor gene in a near-isogenic line (NIL) having r-m allele. PCR amplification of a fragment of the candidate gene Glyma.09G235100 generated a fragment of about 1 kb in the soybean cultivar Clark, whereas a fragment of about 14 kb in addition to fragments of 1 and 1.4 kb were produced in L72-2040, a Clark 63 NIL with the r-m allele. Clark 63 is a NIL of Clark with the rxp and Rps1 alleles. A DNA fragment of 13 060 bp was inserted in the intron of Glyma.09G235100 in L72-2040. The fragment had the CACTA motif at both ends, imperfect terminal inverted repeats (TIR), inverse repetition of short sequence motifs close to the 5' and 3' ends, and a duplication of three nucleotides at the site of integration, indicating that it belongs to a CACTA-superfamily transposable element. We designated the element as Tgm11. Overall nucleotide sequence, motifs of TIR, and subterminal repeats were similar to those of Tgm1 and Tgs1, suggesting that these elements comprise a family.

Colorimetric detection of Cucumber green mottle mosaic virus using unmodified gold nanoparticles as colorimetric probes.

PubMed

Wang, Lin; Liu, Zhanmin; Xia, Xueying; Yang, Cuiyun; Huang, Junyi; Wan, Sibao

2017-05-01

Cucumber green mottle mosaic virus (CGMMV)causes a severe mosaic symptom of watermelon and cucumber, and can be transmitted via infected cucumber seeds, leaves and soil. It remains a challenge to detect this virus to prevent its introduction and infection and spread in fields. For this purpose, a simple and sensitive label-free colorimetric detection method for CGMMV has been developed with unmodified gold nanoparticles (AuNPs) as colorimetric probes. The method is based on the finding that the presence of RT-PCR target products of CGMMV and species-specific probes results in color change of AuNPs from red to blue after NaCl induction. Normally, species-specific probes attach to the surface of AuNPs and thereby increasing their resistance to NaCl-induced aggregation. The concentration of sodium, probes in the reaction system and evaluation of specificity and sensitivity of a novel assay, visual detection of Cucumber green mottle mosaic virus using unmodified AuNPs has been carried out with simple preparation of samples in our study. Through this assay, as low as 30pg/μL of CGMMV RNA was thus detected visually, by the naked eye, without the need for any sophisticated, expensive instrumentation and biochemical reagents. The specificity was 100% and exhibited good reproducibility in our assays. The results note that this assay is highly species-specific, simple, low-cost, and visual for easy detection of CGMMV in plant tissues. Therefore, visual assay is a potentially useful tool for middle or small-scales corporations and entry-exit inspection and quarantine bureau to detect CGMMV in cucumber seeds or plant tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

Black holes in many dimensions at the CERN Large Hadron Collider: testing critical string theory.

PubMed

Hewett, JoAnne L; Lillie, Ben; Rizzo, Thomas G

2005-12-31

We consider black hole production at the CERN Large Hadron Collider (LHC) in a generic scenario with many extra dimensions where the standard model fields are confined to a brane. With approximately 20 dimensions the hierarchy problem is shown to be naturally solved without the need for large compactification radii. We find that in such a scenario the properties of black holes can be used to determine the number of extra dimensions, . In particular, we demonstrate that measurements of the decay distributions of such black holes at the LHC can determine if is significantly larger than 6 or 7 with high confidence and thus can probe one of the critical properties of string theory compactifications.

Greenhouse (III): Gas-Exchange and Seed-to-Seed Experiments on the Russian Space Station MIR and Earth-grown, Ethylene-Treated Wheat Plants

NASA Technical Reports Server (NTRS)

Campbell, William F.; Bingham, Gail; Carman, John; Bubenheim, David; Levinskikh, Margarita; Sytchev, Vladimir N.; Podolsky, Igor B.; Chernova, Lola; Nefodova, Yelena

2001-01-01

The Mir Space Station provided an outstanding opportunity to study long-term plant responses when exposed to a microgravity environment. Furthermore, if plants can be grown to maturity in a microgravity environment, they might be used in future bioregenerative life-support systems (BLSS). The primary objective of the Greenhouse experiment onboard Mir was to grow Super Dwarf and Apogee wheat through complete life cycles in microgravity; i.e., from seed-to-seed-to-seed. Additional objectives were to study chemical, biochemical, and structural changes in plant tissues as well as photosynthesis, respiration, and transpiration (evaporation of water from plants). Another major objective was to evaluate the suitability clothe facilities on Mir for advanced research with plants. The Greenhouse experiment was conducted in the Russian/Bulgarian plant growth chamber, the Svet, to which the United States added instrumentation systems to monitor changes in CO2 and water vapor caused by the plants (with four infrared gas analyzers monitoring air entering and leaving two small plastic chambers). In addition, the US instrumentation also monitored O2; air, leaf (IR), cabin pressure; photon flux; and substrate temperature and substrate moisture (16 probes in the root module). Facility modifications were first performed during the summer of 1995 during Mir 19, which began after STS-72 left Mir. Plant development was monitored by daily observations and some photographs.

Seed predators exert selection on the subindividual variation of seed size.

PubMed

Sobral, M; Guitián, J; Guitián, P; Larrinaga, A R

2014-07-01

Subindividual variation among repeated organs in plants constitutes an overlooked level of variation in phenotypic selection studies, despite being a major component of phenotypic variation. Animals that interact with plants could be selective agents on subindividual variation. This study examines selective pressures exerted during post-dispersal seed predation and germination on the subindividual variation of seed size in hawthorn (Crataegus monogyna). With a seed offering experiment and a germination test, we estimated phenotypic selection differentials for average and subindividual variation of seed size due to seed predation and germination. Seed size affects germination, growth rate and the probability of an individual seed of escaping predation. Longer seeds showed higher germination rates, but this did not result in significant selection on phenotypes of the maternal trees. On the other hand, seed predators avoided wider seeds, and by doing so exerted phenotypic selection on adult average and subindividual variation of seed size. The detected selection on subindividual variation suggests that the levels of phenotypic variation within individual plants may be, at least partly, the adaptive consequence of animal-mediated selection. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Producing the target seed: Seed collection, treatment, and storage

Treesearch

Robert P. Karrfalt

2011-01-01

The role of high quality seeds in producing target seedlings is reviewed. Basic seed handling and upgrading techniques are summarized. Current advances in seed science and technology as well as those on the horizon are discussed.

Converting standard seeding rates for grasses to actual seeding rates per acre.

Treesearch

Joseph F. Pechanec

1950-01-01

Standard rates specifying the amount of grass seed to sow per acre are stated in most of the more recent publications as pounds of live pure seed (lps) to be used. For a seeding project these rates must be converted to the actual amount of seed to sow because seed as purchased from the dealer or grower is never all live pure seed. Even the best lots of seed contain...

The Future of Black Hole Astrophysics in the LIGO-VIRGO-LPF Era

NASA Astrophysics Data System (ADS)

Blandford, Roger; Anantua, Richard

2017-05-01

There is a resurgence of interest in black holes sparked by the LIGO-VIRGO detection of stellar black hole mergers and recent astronomical investigations of jets and accretion disks which probe the spacetime geometry of black holes with masses ranging from a few times the mass of the sun to tens of billions of solar masses. Many of these black holes appear to be spinning rapidly. Some new approaches are described to studying how accreting black holes function as cosmic machines paying special attention to observations of AGN jets, especially with VLBI and γ-ray telescopes. It is assumed that these jets are powered by the electromagnetic extraction of the spin energy of their associated black holes, which are described by the Kerr metric, and that they become simpler and more electromagnetically dominated as the event horizon is approached. The major uncertainty in these models is in describing acceleration and transport of relativistic electrons and positrons and simple phenomenological prescriptions are proposed. The application of these ideas to M87 and 3C279 is outlined and the prospects for learning more, especially from the Event Horizon Telescope and the Cerenkov Telescope Array, are discussed. The main benefit of a better understanding of black hole astrophysics to the LISA mission should be a firmer understanding of the source demographics.

Dark information of black hole radiation raised by dark energy

NASA Astrophysics Data System (ADS)

Ma, Yu-Han; Chen, Jin-Fu; Sun, Chang-Pu

2018-06-01

The "lost" information of black hole through the Hawking radiation was discovered being stored in the correlation among the non-thermally radiated particles (Parikh and Wilczek, 2000 [31], Zhang et al., 2009 [16]). This correlation information, which has not yet been proved locally observable in principle, is named by dark information. In this paper, we systematically study the influences of dark energy on black hole radiation, especially on the dark information. Calculating the radiation spectrum in the existence of dark energy by the approach of canonical typicality, which is reconfirmed by the quantum tunneling method, we find that the dark energy will effectively lower the Hawking temperature, and thus makes the black hole has longer life time. It is also discovered that the non-thermal effect of the black hole radiation is enhanced by dark energy so that the dark information of the radiation is increased. Our observation shows that, besides the mechanical effect (e.g., gravitational lensing effect), the dark energy rises the stored dark information, which could be probed by a non-local coincidence measurement similar to the coincidence counting of the Hanbury-Brown-Twiss experiment in quantum optics.

Plant growth-promoting bacteria elevate the nutritional and functional properties of black cumin and flaxseed fixed oil.

PubMed

Dimitrijević, Snežana; Pavlović, Marija; Maksimović, Svetolik; Ristić, Mihajlo; Filipović, Vladimir; Antonović, Dušan; Dimitrijević-Branković, Suzana

2018-03-01

In order to study the influence of plant growth-promoting bacteria (PGPB) belonging to Streptomyces sp., Paenibacillus sp., and Hymenobacter sp. on fixed oil content of flaxseed and black cumin, 2-year field experiments were conducted. PGPB was applied during seedtime of plants. The extraction of oil from seeds was performed using supercritical CO 2 . The addition of PGPB significantly increases the content of C18:1 (from 16.06 ± 0.03% to 16.97 ± 0.03%) and C18:3 (from 42.97 ± 0.2% to 45.42 ± 0.5%) in flaxseed oil and C18:2 (from 52.68 ± 0.50% to 57.11 ± 0.40%) and C20:2 (from 4.34 ± 0.02% to 4.54 ± 0.03%) in black cumin seed oil. The contents of total polyphenols, flavonoids, and carotenoids, as well as antioxidant activity measured by ferric-reducing ability of plasma assay, were found to be greater in the oil from the seeds of plants treated with the PGPB, compared with the respective non-treated samples. The use of PGPB enhances plant nutritive properties; these represent a great source for obtaining valuable functional food ingredients. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

A Global Spectral Study of Stellar-Mass Black Holes with Unprecedented Sensitivity

NASA Astrophysics Data System (ADS)

Garci, Javier

There are two well established populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, many millions of which are present in each galaxy in the universe, and (ii) supermassive black holes with masses in the range millions to billions of solar masses, which reside in the nucleus of most galaxies. Supermassive black holes play a leading role in shaping galaxies and are central to cosmology. However, they are hard to study because they are dim and they scarcely vary on a human timescale. Luckily, their variability and full range of behavior can be very effectively studied by observing their stellar-mass cousins, which display in miniature the full repertoire of a black hole over the course of a single year. The archive of data collected by NASA's Rossi X-ray Timing Explorer (RXTE) during its 16 year mission is of first importance for the study of stellar-mass black holes. While our ultimate goal is a complete spectral analysis of all the stellar-mass black hole data in the RXTE archive, the goal of this proposal is the global study of six of these black holes. The two key methodologies we bring to the study are: (1) Our recently developed calibration tool that increases the sensitivity of RXTE's detector by up to an order of magnitude; and (2) the leading X-ray spectral "reflection" models that are arguably the most effective means currently available for probing the effects of strong gravity near the event horizon of a black hole. For each of the six black holes, we will fit our models to all the archived spectral data and determine several key parameters describing the black hole and the 10-million-degree gas that surrounds it. Of special interest will be our measurement of the spin (or rate of rotation) of each black hole, which can be as high as tens of thousands of RPM. Profoundly, all the properties of an astronomical black hole are completely defined by specifying its spin and its mass. The main goal of this

Vacuum solutions of five dimensional Einstein equations generated by inverse scattering method. II. Production of the black ring solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomizawa, Shinya; Nozawa, Masato

2006-06-15

We study vacuum solutions of five-dimensional Einstein equations generated by the inverse scattering method. We reproduce the black ring solution which was found by Emparan and Reall by taking the Euclidean Levi-Civita metric plus one-dimensional flat space as a seed. This transformation consists of two successive processes; the first step is to perform the three-solitonic transformation of the Euclidean Levi-Civita metric with one-dimensional flat space as a seed. The resulting metric is the Euclidean C-metric with extra one-dimensional flat space. The second is to perform the two-solitonic transformation by taking it as a new seed. Our result may serve asmore » a stepping stone to find new exact solutions in higher dimensions.« less

Beyond Einstein: From the Big Bang to Black Holes

NASA Astrophysics Data System (ADS)

White, N.

Beyond Einstein is a science-driven program of missions, education and outreach, and technology, to address three questions: What powered the Big Bang? What happens to space, time, and matter at the edge of a Black Hole? What is the mysterious Dark Energy pulling the universe apart? To address the science objectives, Beyond Einstein contains several interlinked elements. The strategic missions Constellation-X and LISA primarily investigate the nature of black holes. Constellation-X is a spectroscopic observatory that uses X-ray emitting atoms as clocks to follow the fate of matter falling into black holes. LISA will be the first space-based gravitational wave observatory uses gravitational waves to measure the dynamic structure of space and time around black holes. Moderate sized probes that are fully competed, peer-reviewed missions (300M-450M) launched every 3-5 years to address the focussed science goals: 1) Determine the nature of the Dark Energy that dominates the universe, 2) Search for the signature of the beginning of the Big Bang in the microwave background and 3) Take a census of Black Holes of all sizes and ages in the universe. The final element is a Technology Program to enable ultimate Vision Missions (after 2015) to directly detect gravitational waves echoing from the beginning of the Big Bang, and to directly image matter near the event horizon of a Black Hole. An associated Education and Public Outreach Program will inspire the next generation of scientists, and support national science standards and benchmarks.

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 1 2014-04-01 2014-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 1 2013-04-01 2013-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 1 2012-04-01 2012-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

Consistent individual differences in seed disperser quality in a seed-eating fish.

PubMed

Pollux, Bart J A

2017-01-01

Animal-mediated seed dispersal (zoochory) is considered to be an important mechanism regulating biological processes at larger spatial scales. To date, intra-specific variation in seed disperser quality within seed-dispersing animals has not been studied. Here, I employed seed feeding trials to quantify individual differences in disperser quality within the common carp (Cyprinus carpio) using seeds of two aquatic plants: unbranched bur-reed (Sparganium emersum, Sparganiaceae) and arrowhead (Sagittaria sagittifolia, Alismataceae). I found substantial variation among carp individuals in their propensity to ingest seeds and their ability to digest them, resulting in up to 31-fold differences in the probability of seed dispersal. In addition, there were significant differences in the time that seeds are retained in their digestive systems, generating a twofold difference in the maximum distance over which they can potentially disperse seeds. I propose that seed-eating animal species consist of individuals that display continuous variation in disperser quality, with at one end of the continuum individuals that are likely to eat seeds, pass them unharmed through their digestive tract and transport them over large distances to new locations (i.e. high-quality seed dispersers) and at the other end individuals that rarely eat seeds, destroy most of the ones they ingest and transport the few surviving seeds over relatively short distances (low-quality seed dispersers). Although individual differences in seed dispersal quality could be the result of a variety of factors, these results underline the ecological and evolutionary potential of such variation for both plants and animals.

Q ‑ Φ criticality and microstructure of charged AdS black holes in f(R) gravity

NASA Astrophysics Data System (ADS)

Deng, Gao-Ming; Huang, Yong-Chang

2017-12-01

The phase transition and critical behaviors of charged AdS black holes in f(R) gravity with a conformally invariant Maxwell (CIM) source and constant curvature are further investigated. As a highlight, this research is carried out by employing new state parameters (T,Q, Φ) and contributes to deeper understanding of the thermodynamics and phase structure of black holes. Our analyses manifest that the charged f(R)-CIM AdS black hole undergoes a first-order small-large black hole phase transition, and the critical behaviors qualitatively behave like a Van der Waals liquid-vapor system. However, differing from the case in Einstein’s gravity, phase structures of the black holes in f(R) theory exhibit an interesting dependence on gravity modification parameters. Moreover, we adopt the thermodynamic geometry to probe the black hole microscopic properties. The results show that, on the one hand, both the Ruppeiner curvature and heat capacity diverge exactly at the critical point, on the other hand, the f(R)-CIM AdS black hole possesses the property as ideal Fermi gases. Of special interest, we discover a microscopic similarity between the black holes and a Van der Waals liquid-vapor system.

A Search for Black Holes and Neutron Stars in the Kepler Field

NASA Astrophysics Data System (ADS)

Orosz, Jerome; Short, Donald; Welsh, William; Windmiller, Gur; Dabney, David

2018-01-01

Black holes and neutron stars represent the final evolutionary stages of the most massive stars. In addition to their use as probes into the evolution of massive stars, black holes and neutron stars are ideal laboratories to test General Relativity in the strong field limit. The number of neutron stars and black holes in the Milky Way is not precisely known, but there are an estimated one billion neutron stars in the galaxy based on the observed numbers of radio pulsars. The number of black holes is about 100 million, based on the behavior of the Initial Mass Function at high stellar masses.All of the known steller-mass black holes (and a fair number of neutron stars) are in ``X-ray binaries'' that were discovered because of their luminous X-ray emission. The requirement to be in an X-ray-emitting binary places a strong observational bias on the discovery of stellar-mass black holes. Thus the 21 known black hole binaries represent only the very uppermost tip of the population iceberg.We have conducted an optical survey using Kepler data designed to uncover black holes and neutron stars in both ``quiescent'' X-ray binaries and ``pre-contact'' X-ray binaries. We discuss how the search was conducted, including how potentially interesting light curves were classified and the how variability types were identified. Although we did not find any convincing candidate neutron star or black hole systems, we did find a few noteworthy binary systems, including two binaries that contain low-mass stars with unusually low albedos.

Black hole growth in the early Universe is self-regulated and largely hidden from view.

PubMed

Treister, Ezequiel; Schawinski, Kevin; Volonteri, Marta; Natarajan, Priyamvada; Gawiser, Eric

2011-06-15

The formation of the first massive objects in the infant Universe remains impossible to observe directly and yet it sets the stage for the subsequent evolution of galaxies. Although some black holes with masses more than 10(9) times that of the Sun have been detected in luminous quasars less than one billion years after the Big Bang, these individual extreme objects have limited utility in constraining the channels of formation of the earliest black holes; this is because the initial conditions of black hole seed properties are quickly erased during the growth process. Here we report a measurement of the amount of black hole growth in galaxies at redshift z = 6-8 (0.95-0.7 billion years after the Big Bang), based on optimally stacked, archival X-ray observations. Our results imply that black holes grow in tandem with their host galaxies throughout cosmic history, starting from the earliest times. We find that most copiously accreting black holes at these epochs are buried in significant amounts of gas and dust that absorb most radiation except for the highest-energy X-rays. This suggests that black holes grew significantly more during these early bursts than was previously thought, but because of the obscuration of their ultraviolet emission they did not contribute to the re-ionization of the Universe.

Effects of rodent species, seed species, and predator cues on seed fate

NASA Astrophysics Data System (ADS)

Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

2011-07-01

Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat ( Dipodomys ordii) and the Great Basin pocket mouse ( Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote ( Canis latrans) vocalization, (3) coyote scent, (4) red fox ( Vulpes vulpes) scent, or (5) short-eared owl ( Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass ( Achnatherum hymenoides) and bluebunch wheatgrass ( Pseudoroegneria spicata), and the non-native cereal rye ( Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

Effects of rodent species, seed species, and predator cues on seed fate

USGS Publications Warehouse

Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

2011-01-01

Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat (Dipodomys ordii) and the Great Basin pocket mouse (Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote (Canis latrans) vocalization, (3) coyote scent, (4) red fox (Vulpes vulpes) scent, or (5) short-eared owl (Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass (Achnatherum hymenoides) and bluebunch wheatgrass (Pseudoroegneria spicata), and the non-native cereal rye (Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

The Crisis in Black and Black.

ERIC Educational Resources Information Center

Hutchinson, Earl Ofari

These essays explore why the historic conflict between blacks and whites in the United States has become a crisis that divides many African Americans. The changing racial dynamic is not marked by conflicts. between the black middle class and the poor, black men and women, the black intellectual elite and rappers, black politicians and the urban…

Timing of seed dispersal generates a bimodal seed bank depth distribution

USGS Publications Warehouse

Espinar, J.L.; Thompson, K.; Garcia, L.V.

2005-01-01

The density of soil seed banks is normally highest at the soil surface and declines monotonically with depth. Sometimes, for a variety of reasons, peak density occurs below the surface but, except in severely disturbed soils, it is generally true that deeper seeds are older. In seasonally dry habitats that develop deep soil cracks during the dry season, it is possible that some seeds fall down cracks and rapidly become deeply buried. We investigated this possibility for three dominant clonal perennials (Scirpus maritimus, S. litoralis, and Juncus subulatus) in the Don??ana salt marsh, a nontidal marsh with a Mediterranean climate located in southwest Spain. Two species, which shed most of their seed during the dry season and have seeds with low buoyancy, had bimodal viable seed depth distributions, with peak densities at the surface and at 16-20 cm. A third species, which shed most seeds after soil cracks had closed and had seeds with high buoyancy, had viable seeds only in surface soil. Bimodal seed bank depth distributions may be relatively common in seasonally dry habitats with fine-textured soils, but their ecological significance has not been investigated.

Black holes from large N singlet models

NASA Astrophysics Data System (ADS)

Amado, Irene; Sundborg, Bo; Thorlacius, Larus; Wintergerst, Nico

2018-03-01

The emergent nature of spacetime geometry and black holes can be directly probed in simple holographic duals of higher spin gravity and tensionless string theory. To this end, we study time dependent thermal correlation functions of gauge invariant observables in suitably chosen free large N gauge theories. At low temperature and on short time scales the correlation functions encode propagation through an approximate AdS spacetime while interesting departures emerge at high temperature and on longer time scales. This includes the existence of evanescent modes and the exponential decay of time dependent boundary correlations, both of which are well known indicators of bulk black holes in AdS/CFT. In addition, a new time scale emerges after which the correlation functions return to a bulk thermal AdS form up to an overall temperature dependent normalization. A corresponding length scale was seen in equal time correlation functions in the same models in our earlier work.

An intermediate-mass black hole in the centre of the globular cluster 47 Tucanae.

PubMed

Kızıltan, Bülent; Baumgardt, Holger; Loeb, Abraham

2017-02-08

Intermediate-mass black holes should help us to understand the evolutionary connection between stellar-mass and super-massive black holes. However, the existence of intermediate-mass black holes is still uncertain, and their formation process is therefore unknown. It has long been suspected that black holes with masses 100 to 10,000 times that of the Sun should form and reside in dense stellar systems. Therefore, dedicated observational campaigns have targeted globular clusters for many decades, searching for signatures of these elusive objects. All candidate signatures appear radio-dim and do not have the X-ray to radio flux ratios required for accreting black holes. Based on the lack of an electromagnetic counterpart, upper limits of 2,060 and 470 solar masses have been placed on the mass of a putative black hole in 47 Tucanae (NGC 104) from radio and X-ray observations, respectively. Here we show there is evidence for a central black hole in 47 Tucanae with a mass of solar masses when the dynamical state of the globular cluster is probed with pulsars. The existence of an intermediate-mass black hole in the centre of one of the densest clusters with no detectable electromagnetic counterpart suggests that the black hole is not accreting at a sufficient rate to make it electromagnetically bright and therefore, contrary to expectations, is gas-starved. This intermediate-mass black hole might be a member of an electromagnetically invisible population of black holes that grow into supermassive black holes in galaxies.