Tissue Distribution and Elimination of Ciguatoxins in Tridacna maxima (Tridacnidae, Bivalvia) Fed Gambierdiscus polynesiensis.

PubMed

Roué, Mélanie; Darius, Hélène Taiana; Ung, André; Viallon, Jérôme; Sibat, Manoella; Hess, Philipp; Amzil, Zouher; Chinain, Mireille

2018-05-10

Ciguatera is a foodborne disease caused by the consumption of seafood contaminated with ciguatoxins (CTXs). Ciguatera-like poisoning events involving giant clams ( Tridacna maxima ) are reported occasionally from Pacific islands communities. The present study aimed at providing insights into CTXs tissue distribution and detoxification rate in giant clams exposed to toxic cells of Gambierdiscus polynesiensis , in the framework of seafood safety assessment. In a first experiment, three groups of tissue (viscera, flesh and mantle) were dissected from exposed individuals, and analyzed for their toxicity using the neuroblastoma cell-based assay (CBA-N2a) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses. The viscera, flesh, and mantle were shown to retain 65%, 25%, and 10% of the total toxin burden, respectively. All tissues reached levels above the safety limit recommended for human consumption, suggesting that evisceration alone, a practice widely used among local populations, is not enough to ensure seafood safety. In a second experiment, the toxin content in contaminated giant clams was followed at different time points (0, 2, 4, and 6 days post-exposure). Observations suggest that no toxin elimination is visible in T. maxima throughout 6 days of detoxification.

Mississippi State University Sustainable Energy Research Center

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

Steele, W. Glenn

The Sustainable Energy Research Center (SERC) project at Mississippi State University included all phases of biofuel production from feedstock development, to conversion to liquid transportation fuels, to engine testing of the fuels. The feedstocks work focused on non-food based crops and yielded an increased understanding of many significant Southeastern feedstocks. an emphasis was placed on energy grasses that could supplement the primary feedstock, wood. Two energy grasses, giant miscanthus and switchgrass, were developed that had increased yields per acre. Each of these grasses was patented and licensed to companies for commercialization. The fuels work focused on three different technologies thatmore » each led to a gasoline, diesel, or jet fuel product. The three technologies were microbial oil, pyrolysis oil, and syngas-to liquid-hydrocarbons« less

Science and Technology Review September 1999

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

Eimerl, D

1999-09-01

This review consists of the following titles; The Laboratory in the News; Life Performance of Complex Systems; A Better Picture of Aging Materials; Researchers Determine Chernobyl Liquidators' Exposure; and Target Chamber's Dedication Marks a Giant Milestone.

Lignocellulosic crop supply chains (eg, Miscanthus, switchgrass, reed canary grass, rye, giant reed, etc.) Chapter 12 of "Biomass Supply Chains for Bioenergy and Biorefining"

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

Roni, Mohammad S.; Cafferty, Kara G.; Hess, J. Richard

This chapter provides an overview of lignocellulosic crop supply chains such as Miscanthus, switch grass, reed canary grass, rye, and giant reed by outlining typical logistic operations in support of a liquid biofuel market. We present two strategies for managing feedstocks within the biomass supply system: (1) the conventional bale feedstock supply system and (2) the advanced supply system concept. Finally, we discuss feedstock blending and integrated landscape management as innovative improvements to the lignocellulosic crop supply chain.

The lead isotopic age of the Earth can be explained by core formation alone.

PubMed

Wood, Bernard J; Halliday, Alex N

2010-06-10

The meaning of the age of the Earth defined by lead isotopes has long been unclear. Recently it has been proposed that the age of the Earth deduced from lead isotopes reflects volatile loss to space at the time of the Moon-forming giant impact rather than partitioning into metallic liquids during protracted core formation. Here we show that lead partitioning into liquid iron depends strongly on carbon content and that, given a content of approximately 0.2% carbon, experimental and isotopic data both provide evidence of strong partitioning of lead into the core throughout the Earth's accretion. Earlier conclusions that lead is weakly partitioned into iron arose from the use of carbon-saturated (about 5% C) iron alloys. The lead isotopic age of the Earth is therefore consistent with partitioning into the core and with no significant late losses of moderately volatile elements to space during the giant impact.

Moving, Moving, Moving- A Giant Rocket Fuel Tank

NASA Image and Video Library

2016-10-07

Technicians moved a giant fuel tank from the Vertical Assembly Center where the tank recently completed friction stir welding to an adjacent work area at NASA's Michoud Assembly Facility in New Orleans. More than 1.7 miles of welds have been completed for core stage hardware at Michoud. This liquid hydrogen fuel tank is the largest piece of the core stage that will provide the fuel for the first flight of NASA's new rocket, the Space Launch System, with the Orion spacecraft in 2018. The tank is more than 130 feet long, and together with the liquid oxygen tank holds 733,000 gallons of propellant to feed the vehicle's four RS-25 engines to produce a total of 2 million pounds of thrust. SLS will have the power and capacity to carry humans to Mars. For more information on the core stage: http://www.nasa.gov/exploration/syste... Video Credit: NASA/MAF/Eric Bordelon

Exobiology of icy satellites

NASA Astrophysics Data System (ADS)

Simakov, M. B.

At the beginning of 2004 the total number of discovered planets near other stars was 119 All of them are massive giants and met practically in all orbits In a habitable zone from 0 8 up to 1 1 AU at less 11 planets has been found starting with HD 134987 and up to HD 4203 It would be naive to suppose existence of life in unique known to us amino-nucleic acid form on the gas-liquid giant planets Nevertheless conditions for onset and evolutions of life can be realized on hypothetical satellites extrasolar planets All giant planets of the Solar system have a big number of satellites 61 of Jupiter 52 of Saturn known in 2003 A small part of them consist very large bodies quite comparable to planets of terrestrial type but including very significant share of water ice Some from them have an atmosphere E g the mass of a column of the Titan s atmosphere exceeds 15 times the mass of the Earth atmosphere column Formation or capture of satellites is a natural phenomenon and satellite systems definitely should exist at extrasolar planets A hypothetical satellite of the planet HD 28185 with a dense enough atmosphere and hydrosphere could have biosphere of terrestrial type within the limits of our notion about an origin of terrestrial biosphere As an example we can see on Titan the largest satellite of Saturn which has a dense nitrogen atmosphere and a large quantity of liquid water under ice cover and so has a great exobiological significance The most recent models of the Titan s interior lead to the conclusion that a substantial liquid layer

Evolution and development of model membranes for physicochemical and functional studies of the membrane lateral heterogeneity.

PubMed

Morigaki, Kenichi; Tanimoto, Yasushi

2018-03-14

One of the main questions in the membrane biology is the functional roles of membrane heterogeneity and molecular localization. Although segregation and local enrichment of protein/lipid components (rafts) have been extensively studied, the presence and functions of such membrane domains still remain elusive. Along with biochemical, cell observation, and simulation studies, model membranes are emerging as an important tool for understanding the biological membrane, providing quantitative information on the physicochemical properties of membrane proteins and lipids. Segregation of fluid lipid bilayer into liquid-ordered (Lo) and liquid-disordered (Ld) phases has been studied as a simplified model of raft in model membranes, including giant unilamellar vesicles (GUVs), giant plasma membrane vesicles (GPMVs), and supported lipid bilayers (SLB). Partition coefficients of membrane proteins between Lo and Ld phases were measured to gauze their affinities to lipid rafts (raftophilicity). One important development in model membrane is patterned SLB based on the microfabrication technology. Patterned Lo/Ld phases have been applied to study the partition and function of membrane-bound molecules. Quantitative information of individual molecular species attained by model membranes is critical for elucidating the molecular functions in the complex web of molecular interactions. The present review gives a short account of the model membranes developed for studying the lateral heterogeneity, especially focusing on patterned model membranes on solid substrates. Copyright © 2018 Elsevier B.V. All rights reserved.

The Primordial Destruction of Moons around Giant Exoplanets through Disk-Driven Planetary Migration

NASA Astrophysics Data System (ADS)

Spalding, Christopher; Batygin, Konstantin; Adams, Fred C.

2015-11-01

The extensive array of satellites around Jupiter and Saturn makes it reasonable to suspect that similar systems of moons might exist around giant extrasolar planets. Observational surveys have revealed a significant population of such giant planets residing at distances of about 1 AU, leading to speculation that some of these 'exomoons' might be capable of maintaining liquid water on their surfaces. Accordingly, many recent efforts have specifically hunted for moons around giant exoplanets. Owing to the lack of detections thus far, it is worth asking whether certain processes intrinsic to planet formation might lead to the loss of moons. Here, we highlight that giant planets are thought to undergo inward migration within their natal disks and show that the very process of migration naturally captures moons into a so-called "evection resonance". Within this resonance, the lunar orbit's eccentricity grows until the moon is lost, either by collision with the planet or through tidal disruption. Whether moons survive or not is critically dependent upon where the planet began its inward trek. In this way, the presence or absence of exomoons can inform us on the extent of inward migration, for which no reliable observational proxy currently exists.

Phosphatidylserine lipids and membrane order precisely regulate the activity of Polybia-MP1 peptide.

PubMed

Alvares, Dayane S; Ruggiero Neto, João; Ambroggio, Ernesto E

2017-06-01

Polybia-MP1 (IDWKKLLDAAKQIL-NH 2 ) is a lytic peptide from the Brazilian wasp venom with known anti-cancer properties. Previous evidence indicates that phosphatidylserine (PS) lipids are relevant for the lytic activity of MP1. In agreement with this requirement, phosphatidylserine lipids are translocated to the outer leaflet of cells, and are available for MP1 binding, depending on the presence of liquid-ordered domains. Here, we investigated the effect of PS on MP1 activity when this lipid is reconstituted in membranes of giant or large liposomes with different lipid-phase states. By monitoring the membrane and soluble luminal content of giant unilamellar vesicles (GUVs), using fluorescence confocal microscopy, we were able to determine that MP1 has a pore-forming activity at the membrane level. Liquid-ordered domains, which were phase-separated within the membrane of GUVs, influenced the pore-forming activity of MP1. Experiments evaluating the membrane-binding and lytic activity of MP1 on large unilamellar vesicles (LUVs), with the same lipid composition as GUVs, demonstrated that there was synergy between liquid-ordered domains and PS, which enhanced both activities. Based on our findings, we propose that the physicochemical properties of cancer cell membranes, which possess a much higher concentration of PS than normal cells, renders them susceptible to MP1 binding and lytic pore formation. These results can be correlated with MP1's potent and selective anti-cancer activity and pave the way for future research to develop cancer therapies that harness and exploit the properties of MP1. Copyright © 2017 Elsevier B.V. All rights reserved.

Coherent Vortices in Strongly Coupled Liquids

NASA Astrophysics Data System (ADS)

Ashwin, J.; Ganesh, R.

2011-04-01

Strongly coupled liquids are ubiquitous in both nature and laboratory plasma experiments. They are unique in the sense that their average potential energy per particle dominates over the average kinetic energy. Using “first principles” molecular dynamics (MD) simulations, we report for the first time the emergence of isolated coherent tripolar vortices from the evolution of axisymmetric flows in a prototype two-dimensional (2D) strongly coupled liquid, namely, the Yukawa liquid. Linear growth rates directly obtained from MD simulations are compared with a generalized hydrodynamic model. Our MD simulations reveal that the tripolar vortices persist over several turn over times and hence may be observed in strongly coupled liquids such as complex plasma, liquid metals and astrophysical systems such as white dwarfs and giant planetary interiors, thereby making the phenomenon universal.

A two-photon view of an enzyme at work: Crotalus atrox venom PLA2 interaction with single-lipid and mixed-lipid giant unilamellar vesicles.

PubMed Central

Sanchez, Susana A; Bagatolli, Luis A; Gratton, Enrico; Hazlett, Theodore L

2002-01-01

We describe the interaction of Crotalus atrox-secreted phospholipase A2 (sPLA2) with giant unilamellar vesicles (GUVs) composed of single and binary phospholipid mixtures visualized through two-photon excitation fluorescent microscopy. The GUV lipid compositions that we examined included 1-palmitoyl-2-oleoyl-phosphatidylcholine, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) (above their gel-liquid crystal transition temperatures) and two well characterized lipid mixtures, 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE):DMPC (7:3) and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC)/1,2-diarachidoyl-sn-glycero-3-phosphocholine (DAPC) (1:1) equilibrated at their phase-coexistence temperature regime. The membrane fluorescence probes, 6-lauroyl-2-(dimethylamino) napthalene, 6-propionyl-2-(dimethylamino) naphthalene, and rhodamine-phosphatidylethanolamine, were used to assess the state of the membrane and specifically mark the phospholipid domains. Independent of their lipid composition, all GUVs were reduced in size as sPLA2-dependent lipid hydrolysis proceeded. The binding of sPLA2 was monitored using a fluorescein-sPLA2 conjugate. The sPLA2 was observed to associate with the entire surface of the liquid phase in the single phospholipid GUVs. In the mixed-lipid GUV's, at temperatures promoting domain coexistence, a preferential binding of the enzyme to the liquid regions was also found. The lipid phase of the GUV protein binding region was verified by the introduction of 6-propionyl-2-(dimethylamino) naphthalene, which partitions quickly into the lipid fluid phase. Preferential hydrolysis of the liquid domains supported the conclusions based on the binding studies. sPLA2 hydrolyzes the liquid domains in the binary lipid mixtures DLPC:DAPC and DMPC:DMPE, indicating that the solid-phase packing of DAPC and DMPE interferes with sPLA2 binding, irrespective of the phospholipid headgroup. These studies emphasize the importance of lateral packing of the lipids in C. atrox sPLA2 enzymatic hydrolysis of a membrane surface. PMID:11916878

Large three-dimensional photonic crystals based on monocrystalline liquid crystal blue phases.

PubMed

Chen, Chun-Wei; Hou, Chien-Tsung; Li, Cheng-Chang; Jau, Hung-Chang; Wang, Chun-Ta; Hong, Ching-Lang; Guo, Duan-Yi; Wang, Cheng-Yu; Chiang, Sheng-Ping; Bunning, Timothy J; Khoo, Iam-Choon; Lin, Tsung-Hsien

2017-09-28

Although there have been intense efforts to fabricate large three-dimensional photonic crystals in order to realize their full potential, the technologies developed so far are still beset with various material processing and cost issues. Conventional top-down fabrications are costly and time-consuming, whereas natural self-assembly and bottom-up fabrications often result in high defect density and limited dimensions. Here we report the fabrication of extraordinarily large monocrystalline photonic crystals by controlling the self-assembly processes which occur in unique phases of liquid crystals that exhibit three-dimensional photonic-crystalline properties called liquid-crystal blue phases. In particular, we have developed a gradient-temperature technique that enables three-dimensional photonic crystals to grow to lateral dimensions of ~1 cm (~30,000 of unit cells) and thickness of ~100 μm (~ 300 unit cells). These giant single crystals exhibit extraordinarily sharp photonic bandgaps with high reflectivity, long-range periodicity in all dimensions and well-defined lattice orientation.Conventional fabrication approaches for large-size three-dimensional photonic crystals are problematic. By properly controlling the self-assembly processes, the authors report the fabrication of monocrystalline blue phase liquid crystals that exhibit three-dimensional photonic-crystalline properties.

A dielectric elastomer actuator coupled with water: snap-through instability and giant deformation

NASA Astrophysics Data System (ADS)

Godaba, Hareesh; Foo, Choon Chiang; Zhang, Zhi Qian; Khoo, Boo Cheong; Zhu, Jian

2015-04-01

A dielectric elastomer actuator is one class of soft actuators which can deform in response to voltage. Dielectric elastomer actuators coupled with liquid have recently been developed as soft pumps, soft lenses, Braille displays, etc. In this paper, we conduct experiments to investigate the performance of a dielectric elastomer actuator which is coupled with water. The membrane is subject to a constant water pressure, which is found to significantly affect the electromechanical behaviour of the membrane. When the pressure is small, the membrane suffers electrical breakdown before snap-through instability, and achieves a small voltage-induced deformation. When the pressure is higher to make the membrane near the verge of the instability, the membrane can achieve a giant voltage-induced deformation, with an area strain of 1165%. When the pressure is large, the membrane suffers pressure-induced snap-through instability and may collapse due to a large amount of liquid enclosed by the membrane. Theoretical analyses are conducted to interpret these experimental observations.

In-flow detection of ultra-small magnetic particles by an integrated giant magnetic impedance sensor

NASA Astrophysics Data System (ADS)

Fodil, K.; Denoual, M.; Dolabdjian, C.; Treizebre, A.; Senez, V.

2016-04-01

We have designed and fabricated a microfluidic system made of glass and polydimethylsiloxane. A micro-magnetometer has been integrated to the system. This sensor is made of a giant magneto-impedance wire known to have very high magnetic sensitivity at room temperature. A liquid-liquid segmented multiphase flow was generated in the channel using a Y-shaped inlet junction. The dispersed phase plugs contained superparamagnetic iron oxide (20 nm) nanoparticles at a molar concentration of 230 mmol/l. We have shown both theoretically and experimentally that in-flow detection of these nanoparticles is performed by the microsystem for concentration as small as 5.47 × 10-9 mol. These performances show that it is conceivable to use this system for ex-vivo analysis of blood samples where superparamagnetic iron oxide nanoparticles, initially used as magnetic contrast agents, could be functionalized for biomarkers fishing. It opens new perspectives in the context of personalized medicine.

Outcome of bone recycling using liquid nitrogen as bone reconstruction procedure in malignant and recurrent benign aggressive bone tumour of distal tibia: A report of four cases.

PubMed

Gede, Eka Wiratnaya I; Ida Ayu, Arrisna Artha; Setiawan I Gn, Yudhi; Aryana Ign, Wien; I Ketut, Suyasa; I Ketut, Siki Kawiyana; Putu, Astawa

2017-01-01

Amputation still considered as primary choice of malignancy treatment in distal tibia. Bone recycling with liquid nitrogen for reconstruction following resection of malignant bone tumours offers many advantages. We presented four patients with osteosarcoma, Ewing sarcoma, adamantinoma and recurrent giant cell tumour over distal tibia. All of the patients underwent wide excision and bone recycling using liquid nitrogen as bone reconstruction. The mean functional Musculoskeletal Tumor Society (MSTS) score was 75% with no infection and local recurrent. The reconstruction provides good local control and functional outcome.

Giant aerosol observations with cloud radar: methodology and effects

NASA Astrophysics Data System (ADS)

Guma Claramunt, Pilar; Madonna, Fabio; Amodeo, Aldo; Bauer-Pfundstein, Matthias; Papagiannopoulos, Nikolaos; Pappalardo, Gelsomina

2017-04-01

Giant aerosol particles can act as Giant Cloud Condensation Nuclei (GCCN), and determine the droplet concentration at the cloud formation, the clouds albedo and lifetime, and the precipitation formation. In addition, depending on their composition, they can also act as IN. It is not yet clear if they can also expedite rain processes. The main techniques used nowadays in measuring aerosols, which are lidar and sun photometer, cannot retrieve aerosol microphysical properties for particles bigger than a few microns, which means that they do not account for giant aerosols. Therefore, the distribution and impact in the atmosphere and climate of these particles is not well known and the aerosol transport models largely underestimate them. Recent studies have demonstrated that cloud radars are able to detect ultragiant volcanic aerosols also at a large distance from the source. In this study, an innovative methodology for the observation of giant aerosols using the millimeter wavelength radar has been developed and applied to 6 years of measurements carried out at CNR-IMAA Atmospheric Observatory (CIAO), in Potenza, South Italy, finding more than 40 giant aerosol events per year and a good agreement with the aerosol climatologic data. Besides, the effects of giant aerosols in the local and regional meteorology have been studied by correlating several atmospheric variables in the time period following the observation of giant particles. The meteorological situation has been assessed through the data classification into cases characterized by different pressure vertical velocities at the upper atmosphere (400 hPa), Giant aerosols are correlated to lower values of the Cloud Optical Depth (COD) in presence of stable or unstable atmospheric conditions while higher values are found for an intermediate stability. The giant aerosols effects on the Liquid Water Path (LWP) are closely linked to those in the Aerosol Optical Thickness (AOD). The highest increases in the LWP occurs together with the increases of AOD. Finally, the effects of giant aerosols on precipitation at a regional scale have been studied. The observation of giant aerosols can be correlated to an enhancement of the accumulated precipitation, which is quite relevant in the first 12 hours after their observation, as well as of the maximum rain rate in presence of the unstable atmospheric conditions. The increase in the maximum rain rate is instead more remarkable in correlation with stable atmospheric conditions and mainly during the first 6 hours after their observations.

Designing lipids for selective partitioning into liquid ordered membrane domains.

PubMed

Momin, Noor; Lee, Stacey; Gadok, Avinash K; Busch, David J; Bachand, George D; Hayden, Carl C; Stachowiak, Jeanne C; Sasaki, Darryl Y

2015-04-28

Self-organization of lipid molecules into specific membrane phases is key to the development of hierarchical molecular assemblies that mimic cellular structures. While the packing interaction of the lipid tails should provide the major driving force to direct lipid partitioning to ordered or disordered membrane domains, numerous examples show that the headgroup and spacer play important but undefined roles. We report here the development of several new biotinylated lipids that examine the role of spacer chemistry and structure on membrane phase partitioning. The new lipids were prepared with varying lengths of low molecular weight polyethylene glycol (EGn) spacers to examine how spacer hydrophilicity and length influence their partitioning behavior following binding with FITC-labeled streptavidin in liquid ordered (Lo) and liquid disordered (Ld) phase coexisting membranes. Partitioning coefficients (Kp Lo/Ld) of the biotinylated lipids were determined using fluorescence measurements in studies with giant unilamellar vesicles (GUVs). Compared against DPPE-biotin, DPPE-cap-biotin, and DSPE-PEG2000-biotin lipids, the new dipalmityl-EGn-biotin lipids exhibited markedly enhanced partitioning into liquid ordered domains, achieving Kp of up to 7.3 with a decaethylene glycol spacer (DP-EG10-biotin). We further demonstrated biological relevance of the lipids with selective partitioning to lipid raft-like domains observed in giant plasma membrane vesicles (GPMVs) derived from mammalian cells. Our results found that the spacer group not only plays a pivotal role for designing lipids with phase selectivity but may also influence the structural order of the domain assemblies.

Isotopic Abundances as Tracers of the Processes of Lunar Formation

NASA Astrophysics Data System (ADS)

Pahlevan, K.

2011-12-01

Ever since Apollo, isotopic abundances have been used as tracers to study lunar formation, in particular, to study the sources of the lunar material. In the last decade, however, a number of isotopic similarities have been observed between the lunar samples and the Earth's mantle such that these two reservoirs are now known to be indistinguishable from one another to high precision for a variety of isotopic tracers. This occurs against the backdrop of a Solar System that exhibits widespread heterogeneity with respect to these tracers, a situation that strongly argues that the source of the lunar material is the silicate Earth. To reconcile this observation with the fact that the Moon is thought to result from the collision of two isotopically distinct planetary bodies, a scenario has emerged in which the material from the Moon-forming impactor and the proto-Earth are homogenized in the aftermath of the giant impact. This takes place via turbulent mixing in the time after the giant impact but before lunar accretion while the Earth-Moon system exists in the form of a continuous, high-temperature fluid. Importantly, this high-temperature phase of the evolution occurs in the presence of at least two phases (liquid + vapor) making possible chemical and isotopic fractionation. While equilibrium isotopic fractionation tends to zero at high temperatures, and the post giant impact environment experiences some of the highest temperatures encountered in the Earth sciences, there are several factors that nevertheless make equilibrium isotope effects important probes of this early evolution. (1) Because the vaporization of silicates involves decomposition reactions, the bonding environment for elements in the liquid is often very different from that in the vapor. This difference makes the magnitude of isotopic fractionation intrinsically large, even at the relevant temperatures. (2) Since the isotopic composition of a silicate liquid and co-existing vapor are distinctly different, if the Moon preferentially forms from the liquid or vapor relative to the Earth, mass-dependent isotopic differences at the planetary scale may arise. The large density contrast between liquid and vapor makes phase separation possible. (3) The precision with which planetary isotopic compositions can be determined has increased such that measurements are sensitive to even small degrees of high-temperature phase separation. Using thermodynamic models of silicate liquids to determine the partial vaporization behavior of the major elements, we will present calculations of isotopic fractionation due to liquid-vapor separation for the elements iron, magnesium, silicon, and oxygen. Improvements in analytical precision have largely settled the question of the source of the lunar material - the Earth's mantle - and isotopic measurements are now beginning to yield insight into the high-temperatures processes operating during lunar formation.

A high resolution liquid xenon imaging telescope for 0.3-10 MeV gamma-ray astrophysics: Construction and initial balloon flights

NASA Technical Reports Server (NTRS)

Aprile, Elena

1994-01-01

An instrument is described which will provide a direct image of gamma-ray line or continuum sources in the energy range 300 keV to 10 MeV. The use of this instrument to study the celestial distribution of the (exp 26)Al isotope by observing the 1.809 MeV deexcitation gamma-ray line is illustrated. The source location accuracy is 2' or better. The imaging telescope is a liquid xenon time projection chamber coupled with a coded aperture mask (LXe-CAT). This instrument will confirm and extend the COMPTEL observations from the Compton Gamma-Ray Observatory (CGRO) with an improved capability for identifying the actual Galactic source or sources of (exp 26)Al, which are currently not known with certainty. sources currently under consideration include red giants on the asymptotic giant branch (AGB), novae, Type 1b or Type 2 supernovae, Wolf-Rayet stars and cosmic-rays interacting in molecular clouds. The instrument could also identify a local source of the celestial 1.809 MeV gamma-ray line, such as a recent nearby supernova.

Greater taxol yield of fungus Pestalotiopsis hainanensis from dermatitic scurf of the giant panda (Ailuropoda melanoleuca).

PubMed

Gu, Yu; Wang, Yanlin; Ma, Xiaoping; Wang, Chengdong; Yue, Guizhou; Zhang, Yuetian; Zhang, Yunyan; Li, Shanshan; Ling, Shanshan; Liu, Xiaomin; Wen, Xintian; Cao, Sanjie; Huang, Xiaobo; Deng, Junliang; Zuo, Zhicai; Yu, Shumin; Shen, Liuhong; Wu, Rui

2015-01-01

While taxol yields of fungi from non-animal sources are still low, whether Pestalotiopsis hainanensis isolated from the scurf of a dermatitic giant panda, Ailuropoda melanoleuca, provides a greater taxol yield remains unknown. The objective of the study was to determine the corresponding taxol yield. The structure of the taxol produced by the fungus was evaluated by thin layer chromatography (TLC), ultraviolet (UV) spectroscopy, high-performance liquid chromatography (HPLC), (1)H and (13)C nuclear magnetic resonance spectroscopy ((1)H-NMR and (13)C-NMR), and time-of-flight mass spectrometry (TOF-MS), with standard taxol as a control. The results demonstrated that the P. hainanensis fungus produced taxol, which had the same structure as the standard taxol and yield of 1,466.87 μg/L. This fungal taxol yield from the dermatitic giant panda was significantly greater than those of fungus from non-animal sources. The taxol-producing fungus may be a potential candidate for the production of taxol on an industrial scale.

[Giant cystic lymphangioma breast. Report of a case with 20-year follow-up and review of the literature].

PubMed

Vargas-Hernández, Víctor Manuel; Tovar-Rodríguez, José María; Moreno-Eutimio, Mario Adán; Acosta-Altamirano, Gustavo

2014-01-01

Lymphangiomas are congenital malformations or acquired (secondary to trauma, infection or neoplasia) in the mammary gland, are extremely rare. These lesions tend to infiltrate surrounding tissues and malignant degeneration is extremely rare. Clinically manifests as benign masses, slow growing; diagnosed clinically and by imaging studies. Suegery with removal of the mass is performed for aesthetic reasons and to make differential diagnosis with other common injuries. Women 45 years of age with progressive increase in size of the left breast, breast trauma concerns and has no other symptoms.The histologic diagnosis was cystic lymphangioma giant left mammary gland. Lymphangiomas are uncommon lesions and extremely rare in the mammary gland, locally aggresive behavior and are benign, where abnormal lymphatic tissue has some ability to proliferate and accumulate large amounts of liquid, representing cystic appearance, as presented in our case. Local surgical excision is the treatment. In this first case of giant breast cystic lymphangioma reported in Mexico, which corroborates the benignity of the lesion.

Melting curve of SiO2 at multimegabar pressures: implications for gas giants and super-Earths.

PubMed

González-Cataldo, Felipe; Davis, Sergio; Gutiérrez, Gonzalo

2016-05-23

Ultrahigh-pressure phase boundary between solid and liquid SiO2 is still quite unclear. Here we present predictions of silica melting curve for the multimegabar pressure regime, as obtained from first principles molecular dynamics simulations. We calculate the melting temperatures from three high pressure phases of silica (pyrite-, cotunnite-, and Fe2P-type SiO2) at different pressures using the Z method. The computed melting curve is found to rise abruptly around 330 GPa, an increase not previously reported by any melting simulations. This is in close agreement with recent experiments reporting the α-PbO2-pyrite transition around this pressure. The predicted phase diagram indicates that silica could be one of the dominant components of the rocky cores of gas giants, as it remains solid at the core of our Solar System's gas giants. These results are also relevant to model the interior structure and evolution of massive super-Earths.

Melting curve of SiO2 at multimegabar pressures: implications for gas giants and super-Earths

PubMed Central

González-Cataldo, Felipe; Davis, Sergio; Gutiérrez, Gonzalo

2016-01-01

Ultrahigh-pressure phase boundary between solid and liquid SiO2 is still quite unclear. Here we present predictions of silica melting curve for the multimegabar pressure regime, as obtained from first principles molecular dynamics simulations. We calculate the melting temperatures from three high pressure phases of silica (pyrite-, cotunnite-, and Fe2P-type SiO2) at different pressures using the Z method. The computed melting curve is found to rise abruptly around 330 GPa, an increase not previously reported by any melting simulations. This is in close agreement with recent experiments reporting the α-PbO2–pyrite transition around this pressure. The predicted phase diagram indicates that silica could be one of the dominant components of the rocky cores of gas giants, as it remains solid at the core of our Solar System’s gas giants. These results are also relevant to model the interior structure and evolution of massive super-Earths. PMID:27210813

Self-determined shapes and velocities of giant near-zero drag gas cavities

PubMed Central

Vakarelski, Ivan U.; Klaseboer, Evert; Jetly, Aditya; Mansoor, Mohammad M.; Aguirre-Pablo, Andres A.; Chan, Derek Y. C.; Thoroddsen, Sigurdur T.

2017-01-01

Minimizing the retarding force on a solid moving in liquid is the canonical problem in the quest for energy saving by friction and drag reduction. For an ideal object that cannot sustain any shear stress on its surface, theory predicts that drag force will fall to zero as its speed becomes large. However, experimental verification of this prediction has been challenging. We report the construction of a class of self-determined streamlined structures with this free-slip surface, made up of a teardrop-shaped giant gas cavity that completely encloses a metal sphere. This stable gas cavity is formed around the sphere as it plunges at a sufficiently high speed into the liquid in a deep tank, provided that the sphere is either heated initially to above the Leidenfrost temperature of the liquid or rendered superhydrophobic in water at room temperature. These sphere-in-cavity structures have residual drag coefficients that are typically less than 110 those of solid objects of the same dimensions, which indicates that they experienced very small drag forces. The self-determined shapes of the gas cavities are shown to be consistent with the Bernoulli equation of potential flow applied on the cavity surface. The cavity fall velocity is not arbitrary but is uniquely predicted by the sphere density and cavity volume, so larger cavities have higher characteristic velocities. PMID:28913434

Review of exchange processes on Ganymede in view of its planetary protection categorization.

PubMed

Grasset, O; Bunce, E J; Coustenis, A; Dougherty, M K; Erd, C; Hussmann, H; Jaumann, R; Prieto-Ballesteros, O

2013-10-01

In this paper, we provide a detailed review of Ganymede's characteristics that are germane to any consideration of its planetary protection requirements. Ganymede is the largest moon in our solar system and is the subject of one of the main science objectives of the JUICE mission to the jovian system. We explore the probability of the occurrence of potentially habitable zones within Ganymede at present, including those both within the deep liquid ocean and those in shallow liquid reservoirs. We consider the possible exchange processes between the surface and any putative habitats to set some constraints on the planetary protection approach for this moon. As a conclusion, the "remote" versus "significant" chance of contamination will be discussed, according to our current understanding of this giant icy moon. Based on the different estimates we investigate here, it appears extremely unlikely that material would be exchanged downward through the upper icy layer of Ganymede and, thus, bring material into the ocean over timescales consistent with the survival of microorganisms.

Optical stretching as a tool to investigate the mechanical properties of lipid bilayers.

PubMed

Solmaz, Mehmet E; Sankhagowit, Shalene; Biswas, Roshni; Mejia, Camilo A; Povinelli, Michelle L; Malmstadt, Noah

2013-10-07

Measurements of lipid bilayer bending modulus by various techniques produce widely divergent results. We attempt to resolve some of this ambiguity by measuring bending modulus in a system that can rapidly process large numbers of samples, yielding population statistics. This system is based on optical stretching of giant unilamellar vesicles (GUVs) in a microfluidic dual-beam optical trap (DBOT). The microfluidic DBOT system is used here to measure three populations of GUVs with distinct lipid compositions. We find that gel-phase membranes are significantly stiffer than liquid-phase membranes, consistent with previous reports. We also find that the addition of cholesterol does not alter the bending modulus of membranes composed of a monounsaturated phospholipid.

PREFACE: Workshop Photograph and Program

NASA Astrophysics Data System (ADS)

2011-07-01

Workshop photograph Workshop Program Sunday 28 March 201019:00-21:00 Reception at Okura Frontier Hotel Tsukuba(Buffet style dinner with drink) Monday 29 March 2010Introduction (Chair: André Rubbia (ETH Zurich))09:00 Welcome address (05') Atsuto Suzuki (KEK)09:05 Message from CERN on neutrino physics (10') Sergio Bertolucci (CERN)09:15 Message from FNAL on neutrino physics (10') Young Kee Kim (FNAL)09:25 Message from KEK on neutrino physics (10') Koichiro Nishikawa (KEK)09:35 Introductory remark on GLA2010 (10') Takuya Hasegawa (KEK) Special session (Chair: Koichiro Nishikawa (KEK))09:45 The ICARUS Liquid Argon TPC (45') Carlo Rubbia (CERN)10:30-11:00 Coffee break Main goals of Giant Liquid Argon Charge Imaging Experiments I (Chair: Takashi Kobayashi (KEK))11:00 Results from massive underground detectors (non accelerator) (30') Takaaki Kajita (ICRR, U. of Tokyo)11:30 Present long baseline neutrino experiments (30') Chang Kee Jung (SUNY Stony Brook)12:00-12:10 Workshop picture12:10-14:00 Lunch break Main goals of Giant Liquid Argon Charge Imaging Experiments II (Chair: Takashi Kobayashi (KEK))14:00 Physics goals of the next generation massive underground experiments (30') David Wark (Imperial College London)14:30 Near detectors for long baseline neutrino experiments (20') Tsuyoshi Nakaya (Kyoto U.) Lessons on Liquid Argon Charge Imaging technology from ongoing developments (Chair: Chang Kee Jung (SUNY Stony Brook))14:50 WARP (30') Claudio Montanari (U. of Pavia)15:20 ArDM (30') Alberto Marchionni (ETH Zurich)15:50 From ArgoNeuT to MicroBooNE (30') Bonnie Fleming (Yale U.)16:20 250L (30') Takasumi Maruyama (KEK)16:50 The DEAP/CLEAN project (20') Mark Boulay (Queen's U.)17:10-17:40 Coffee break Lessons from Xe based Liquids Imaging detectors (Chair: Flavio Cavanna (U. of L'Aquilla))17:30 MEG (20') Satoshi Mihara (KEK)17:50 The XENON project (20') Elena Aprile (Columbia U.)18:10 XMASS (20') Hiroyuki Sekiya (ICRR, U. of Tokyo) Studies on physics performance (Chair: Bonnie Fleming (Yale U.))18:30 Supernovae neutrino detection (20') Ines Gil-Botella (CIEMAT)18:50 Neutrino cross-section in Liquid Argon in the GeV range (15') Flavio Cavanna (U. of L'Aquila)19:05 Analysis of the ArgoNeuT neutrino data (15') Carl Bromberg (Michigan State U.)19:20 Neutrino event reconstruction (15') Gary Barker (U. of Warwick) Tuesday 30 March 2010Ways to improve the Liquid Argon Charge Imaging technology I (Chair: Christos Touramanis (U. of Liverpool))09:00 Liquid Argon LEM TPC (30') Filippo Resnati (ETH Zurich)09:30 Micromegas for charge readout of double phase liquid Argon large TPCs (20') Alain Delbart (Saclay)09:50 Development of Thick-GEMs for GEM-TPC Tracker (20') Fuminori Sakuma (RIKEN)10:10 Optical readout of the ionization (20') Neil Spooner (U. of Sheffield)10:30 Scintillation light readout (20') Kostas Mavrokoridis (U. of Liverpool)10:50-11:10 Coffee break Ways to improve the Liquid Argon Charge Imaging technology II (Chair: Alberto Marchionni (ETH Zurich))11:10 Development of cold electronics (30') Veljko Radeka (BNL)11:40 Development of a frontend ASIC and DAQ system Dario Autiero (IPN Lyon)12:00 CAEN digitizers (20') Carlo Tintori (CAEN)12:20 Recent results from Liquid Argon R&D activity (20') Masashi Tanaka (KEK)12:40 Results from the materials test stand and status of LAPD (20') Brian Rebel (FNAL)13:00 Purging and purification: 6 m3 @CERN (20') Alessandro Curioni (ETH Zurich)13:20-14:30 Lunch break14:30-20:00 Trip to J-PARC to visit T2K Beam Facility and Near Detector20:00-22:00 Workshop dinner at Okura Frontier Hotel Tsukuba Wednesday 31 March 2010Ways to improve the Liquid Argon Charge Imaging technology III (Chair: Takasumi Maruyama (KEK))09:00 ArgonTube and UV laser ionization (25') Biagio Rossi (U. of Bern)09:25 Detector magnetization (15') Andreas Badertscher (ETH Zurich)09:40 HV system (25') Sosuke Horikawa (ETH Zurich) Localization studies (Chair: Takuya Hasegawa (KEK))10:05 Okinoshima site study (20') Masakazu Yoshioka (KEK)10:25 LAGUNA sites study (30') Guido Nuijten (Rockplan)10:55 FNAL/DUSEL project (20') Regina Rameika (FNAL)11:15-11:35 Coffee break Future steps towards the realization of Giant Liquid Argon Charge Imaging detectors (Chair: Takuya Hasegawa (KEK))11:35 LBNE Liquid Argon option (30') Bruce Baller (FNAL)12:05 Towards a 100 kton Liquid Argon experiment (30') André Rubbia (ETH Zurich)12:35 Discussion (30')13:05 Final remark (05') Takuya Hasegawa (KEK)

HIGH-PRESSURE PHYSICS. Direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium.

PubMed

Knudson, M D; Desjarlais, M P; Becker, A; Lemke, R W; Cochrane, K R; Savage, M E; Bliss, D E; Mattsson, T R; Redmer, R

2015-06-26

Eighty years ago, it was proposed that solid hydrogen would become metallic at sufficiently high density. Despite numerous investigations, this transition has not yet been experimentally observed. More recently, there has been much interest in the analog of this predicted metallic transition in the dense liquid, due to its relevance to planetary science. Here, we show direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium. Experimental determination of the location of this transition provides a much-needed benchmark for theory and may constrain the region of hydrogen-helium immiscibility and the boundary-layer pressure in standard models of the internal structure of gas-giant planets. Copyright © 2015, American Association for the Advancement of Science.

Atmospheres of the Giant Planets

NASA Technical Reports Server (NTRS)

Ingersoll, Andrew P.

2002-01-01

The giant planets, Jupiter, Saturn, Uranus, and Neptune, are fluid objects. They have no solid surfaces because the light elements constituting them do not condense at solar-system temperatures. Instead, their deep atmospheres grade downward until the distinction between gas and liquid becomes meaningless. The preceding chapter delved into the hot, dark interiors of the Jovian planets. This one focuses on their atmospheres, especially the observable layers from the base of the clouds to the edge of space. These veneers arc only a few hundred kilometers thick, less than one percent of each planet's radius, but they exhibit an incredible variety of dynamic phenomena. The mixtures of elements in these outer layers resemble a cooled-down piece of the Sun. Clouds precipitate out of this gaseous soup in a variety of colors. The cloud patterns are organized by winds, which are powered by heat derived from sunlight (as on Earth) and by internal heat left over from planetary formation. Thus the atmospheres of the Jovian planets are distinctly different both compositionally and dynamically from those of the terrestrial planets. Such differences make them fascinating objects for study, providing clues about the origin and evolution of the planets and the formation of the solar system.

Satellites of giant planets — possible sites for origin and existence of biospheres

NASA Astrophysics Data System (ADS)

Simakov, Michael B.

All giant planets of the Solar system have a big number of satellites (61 of Jupiter, 52 of Saturn, known in 2003). A small part of them consist very large bodies, quite comparable to planets of terrestrial type, but including very significant share of water ice. Some from them have an atmosphere. E.g., the mass of a column of the Titan’s atmosphere exceeds 15 times the mass of the Earth atmosphere column. Formation (or capture) of satellites is a natural phenomenon, and satellite systems definitely should exist at extrasolar planets. As an example, we can see on Titan, the largest satellite of Saturn, which has a dense nitrogen atmosphere and a large quantity of liquid water under ice cover and so has a great exobiological significance. The most recent models of the Titan’s interior lead to the conclusion that a substantial liquid layer exists today under relatively thin ice cover inside Titan. The putative internal water ocean along with complex atmospheric photochemistry provide some exobiological niches on this body: (1) an upper layer of the internal water ocean; (2) pores, veins, channels and pockets filled with brines inside of the lowest part of the icy layer; (3) the places of cryogenic volcanism; (4) set of caves in icy layer connecting with cryovolcanic processes; (5) the brine-filled cracks in icy crust caused by tidal forces; (6) liquid water pools on the surface originated from meteoritic strikes; (7) the sites of hydrothermal activity on the bottom of the ocean. We can see all conditions needed for origin and evolution of biosphere — liquid water, complex organic chemistry and energy sources for support of biological processes — are on the Saturnian moon. Galileo spacecraft has given indications, primarily from magnetometer and gravity data, of the possibility that three of Jupiter’s four large moons, Europa, Ganymede and Callisto have such oceans also. The existing of liquid water ocean within icy world can be consequences of the physical properties of water ice, and they neither require the addition of antifreeze substances nor any other special conditions. On Earth life exists in all niches where water exists in liquid form for at least a portion of the year. Possible metabolic processes, such as nitrate/nitrite reduction, sulfate reduction and methanogenesis could be suggested for internal oceans of Titan and Jovanian satellites. Excreted products of the primary chemoautotrophic organisms could serve as a source for other types of microorganisms (heterotrophes). Subglacial life may be widespread among such planetary bodies as satellites of extrasolar giant planets, detected in our Galaxy.

Lesson to be remembered from a skull base tumor.

PubMed

Briet, C; Bernard, F; Rodien, P

2017-09-01

The natural history of giant prolactinomas is not known. While it is commonly accepted that the enlargement of microadenoma is rare and more limited than macroadenoma, it is so far uncommon that macroadenoma progress to giant adenoma. Thus, spontaneous enlargement of adenomas is poorly documented. We report the unusual history of undiagnosed microprolactinoma, revealed 12years later at the stage of a giant adenoma presenting as a skull base tumor. This unique observation provides information on the natural history of giant adenomas and arguments for particular attention to microadenomas with signs of invasion. Moreover, this clinical case highlights the need for a prolactin dosage for all midline skull base tumors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Deep melting reveals liquid structural memory and anomalous ferromagnetism in bismuth.

PubMed

Shu, Yu; Yu, Dongli; Hu, Wentao; Wang, Yanbin; Shen, Guoyin; Kono, Yoshio; Xu, Bo; He, Julong; Liu, Zhongyuan; Tian, Yongjun

2017-03-28

As an archetypal semimetal with complex and anisotropic Fermi surface and unusual electric properties (e.g., high electrical resistance, large magnetoresistance, and giant Hall effect), bismuth (Bi) has played a critical role in metal physics. In general, Bi displays diamagnetism with a high volumetric susceptibility ([Formula: see text]10 -4 ). Here, we report unusual ferromagnetism in bulk Bi samples recovered from a molten state at pressures of 1.4-2.5 GPa and temperatures above [Formula: see text]1,250 K. The ferromagnetism is associated with a surprising structural memory effect in the molten state. On heating, low-temperature Bi liquid (L) transforms to a more randomly disordered high-temperature liquid (L') around 1,250 K. By cooling from above 1,250 K, certain structural characteristics of liquid L' are preserved in L. Bi clusters with characteristics of the liquid L' motifs are further preserved through solidification into the Bi-II phase across the pressure-independent melting curve, which may be responsible for the observed ferromagnetism.

Deep melting reveals liquid structural memory and anomalous ferromagnetism in bismuth

PubMed Central

Shu, Yu; Yu, Dongli; Hu, Wentao; Wang, Yanbin; Shen, Guoyin; Kono, Yoshio; Xu, Bo; He, Julong; Liu, Zhongyuan; Tian, Yongjun

2017-01-01

As an archetypal semimetal with complex and anisotropic Fermi surface and unusual electric properties (e.g., high electrical resistance, large magnetoresistance, and giant Hall effect), bismuth (Bi) has played a critical role in metal physics. In general, Bi displays diamagnetism with a high volumetric susceptibility (∼10−4). Here, we report unusual ferromagnetism in bulk Bi samples recovered from a molten state at pressures of 1.4–2.5 GPa and temperatures above ∼1,250 K. The ferromagnetism is associated with a surprising structural memory effect in the molten state. On heating, low-temperature Bi liquid (L) transforms to a more randomly disordered high-temperature liquid (L′) around 1,250 K. By cooling from above 1,250 K, certain structural characteristics of liquid L′ are preserved in L. Bi clusters with characteristics of the liquid L′ motifs are further preserved through solidification into the Bi-II phase across the pressure-independent melting curve, which may be responsible for the observed ferromagnetism. PMID:28289195

Turbulent convection in liquid metal with and without rotation

PubMed Central

King, Eric M.; Aurnou, Jonathan M.

2013-01-01

The magnetic fields of Earth and other planets are generated by turbulent, rotating convection in liquid metal. Liquid metals are peculiar in that they diffuse heat more readily than momentum, quantified by their small Prandtl numbers, . Most analog models of planetary dynamos, however, use moderate fluids, and the systematic influence of reducing is not well understood. We perform rotating Rayleigh–Bénard convection experiments in the liquid metal gallium over a range of nondimensional buoyancy forcing and rotation periods (E). Our primary diagnostic is the efficiency of convective heat transfer . In general, we find that the convective behavior of liquid metal differs substantially from that of moderate fluids, such as water. In particular, a transition between rotationally constrained and weakly rotating turbulent states is identified, and this transition differs substantially from that observed in moderate fluids. This difference, we hypothesize, may explain the different classes of magnetic fields observed on the Gas and Ice Giant planets, whose dynamo regions consist of and fluids, respectively. PMID:23569262

Giant lateral electrostriction in ferroelectric liquid-crystalline elastomers

NASA Astrophysics Data System (ADS)

Lehmann, W.; Skupin, H.; Tolksdorf, C.; Gebhard, E.; Zentel, R.; Krüger, P.; Lösche, M.; Kremer, F.

2001-03-01

Mechanisms for converting electrical energy into mechanical energy are essential for the design of nanoscale transducers, sensors, actuators, motors, pumps, artificial muscles, and medical microrobots. Nanometre-scale actuation has to date been mainly achieved by using the (linear) piezoelectric effect in certain classes of crystals (for example, quartz), and `smart' ceramics such as lead zirconate titanate. But the strains achievable in these materials are small-less than 0.1 per cent-so several alternative materials and approaches have been considered. These include grafted polyglutamates (which have a performance comparable to quartz), silicone elastomers (passive material-the constriction results from the Coulomb attraction of the capacitor electrodes between which the material is sandwiched) and carbon nanotubes (which are slow). High and fast strains of up to 4 per cent within an electric field of 150MVm-1 have been achieved by electrostriction (this means that the strain is proportional to the square of the applied electric field) in an electron-irradiated poly(vinylidene fluoride-trifluoroethylene) copolymer. Here we report a material that shows a further increase in electrostriction by two orders of magnitude: ultrathin (less than 100nanometres) ferroelectric liquid-crystalline elastomer films that exhibit 4 per cent strain at only 1.5 MVm-1. This giant electrostriction was obtained by combining the properties of ferroelectric liquid crystals with those of a polymer network. We expect that these results, which can be completely understood on a molecular level, will open new perspectives for applications.

[Giant idiopathic hydronephrosis: toward a two-step therapeutic approach].

PubMed

Boudhaye, Taher Ismail; Sidimalek, Mohamed; Jdoud, Cheikhani

2017-01-01

Giant hydronephrosis is rare. It is usually caused by ureteropelvic junction syndrome. We here report the unusual case of a patient hospitalized with giant hydronephrosis associated with impaired general condition. Diagnosis was based on CT scan. The patient underwent deferred nephrectomy after percutaneous drainage.

Liquid in vitro culture for the propagation of Arundo donax.

PubMed

Herrera-Alamillo, Miguel Angel; Robert, Manuel L

2012-01-01

We describe a simple and inexpensive plant micropropagation system for giant reed (Arundo donax L.) that uses axillary buds from the lateral stems of elite plants selected from field- or nursery-grown plants. The buds, attached to the stems are cultured in stationary liquid MS culture medium, supplemented with indole 3-acetic acid and kinetin. This formulation is the only one required for all the stages. Contrary to what happens in semisolid medium where roots are not formed, the plants cultured in liquid medium are whole plants with shoots and roots that develop at the same time. The survival rate of these plants when transferred to soil is close to 100% during acclimatization. A clonal line of 900 plants from a single mother plant can be produced in 4 months.

Free amino acid profiling in the giant puffball mushroom (Calvatia gigantea) using UPLC-MS/MS.

PubMed

Kıvrak, İbrahim; Kıvrak, Şeyda; Harmandar, Mansur

2014-09-01

Wild edible and medicinal mushroom, Calvatia gigantea, was quantitatively analyzed for the determination of its free amino acids using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The concentrations of total free amino acids, essential and non-essential amino acids were 199.65 mg/100 g, 113.69 mg/100 g, and 85.96 mg/100 g in C. gigantea, respectively. This study showed that C. gigantea, so called a giant puffball mushroom, has free amino acids content. The essential amino acids: tryptophan, isoleucine, valine, phenylalanine, leucine, threonine, lysine, histidine, methionine, and the non-essential amino acids: tyrosine, 4-hyrdroxy proline, arginine, proline, glycine, serine, alanine, glutamine, glutamic acid, aspargine, aspartic acid were detected. Copyright © 2014 Elsevier Ltd. All rights reserved.

Water in Solar system

NASA Astrophysics Data System (ADS)

Vidmachenko, A. P.

2018-05-01

Water consists of two most common chemical elements in the universe: hydrogen and oxygen. At the study of the solar and other planetary systems, water was found on planets, their satellites, in cometary nuclei, in asteroids, dwarf planets such as Ceres and Pluto. Water also occurs in the giant molecular clouds at interstellar space, in the materials of protoplanetary disks, in the atmospheres of exoplanets. In addition, in liquid form, water can also be under the surface. Most of the satellites of the giant planets also contain a huge amount of water ice. Some satellites of Saturn and Jupiter even give evidence of the presence of oceans under their surface. These include, for example, Enceladus, Titan and Dione in Saturn; Europe, Ganymede and Callisto near Jupiter; Here we will also include the satellite of Neptune - Triton.

Optical stretching as a tool to investigate the mechanical properties of lipid bilayers†

PubMed Central

Solmaz, Mehmet E.; Sankhagowit, Shalene; Biswas, Roshni; Mejia, Camilo A.; Povinelli, Michelle L.; Malmstadt, Noah

2013-01-01

Measurements of lipid bilayer bending modulus by various techniques produce widely divergent results. We attempt to resolve some of this ambiguity by measuring bending modulus in a system that can rapidly process large numbers of samples, yielding population statistics. This system is based on optical stretching of giant unilamellar vesicles (GUVs) in a microfluidic dual-beam optical trap (DBOT). The microfluidic DBOT system is used here to measure three populations of GUVs with distinct lipid compositions. We find that gel-phase membranes are significantly stiffer than liquid-phase membranes, consistent with previous reports. We also find that the addition of cholesterol does not alter the bending modulus of membranes composed of a monounsaturated phospholipid. PMID:24244843

Understanding Li enhancement in K giants and role of accurate parallaxes

NASA Astrophysics Data System (ADS)

Singh, Raghubar; Reddy, B. E.

2018-04-01

Our recent studies based on a large sample of K giants with Hipparcos parallaxes and spectroscopic analysis resulted more than a dozen new Li-rich K giants including few super Li-rich ones. Most of the Li-rich K giants including the new ones appear to occur at the luminosity bump in the HR diagram. However, one can't rule out the possibility of overlap with the clump region where core He-burning K giants reside post He-flash at the tip of RGB. It is important to distinguish field K giants of clump from the bump region in the HR diagram to understand clues for Li production in K giants. In this poster, we explore whether GAIA parallaxes improve to disentangle clump from bump region, more precisely.

Electrical resistivity of the liquid phase of vesicular suspensions prepared by different methods

NASA Astrophysics Data System (ADS)

Vitkova, V.; Antonova, K.; Popkirov, G.; Mitov, M. D.; Ermakov, Yu A.; Bivas, I.

2010-11-01

Giant lipid vesicles are obtained mainly by two methods of formation: (i) electroformation and (ii) gentle hydration (spontaneous swelling). Very often the electoformation is carried out in experimental cells consisting of indium-tin oxide (ITO) coated plates as electrodes and various polymer spacers. In the present work, the influence of the ITO coatings and the polymer spacers on the electrical resistivity of the liquid medium of electroformed vesicle suspensions is examined by means of electrochemical impedance spectroscopy (EIS). Our study is intended to point out possible implications of the electroformation method, especially in cases when phenomena, related to electric properties of the vesicle membranes, are investigated.

P - ρ - T data for H2O up to 260 GPa under laser-driven shock loading

NASA Astrophysics Data System (ADS)

Kimura, T.; Ozaki, N.; Sano, T.; Okuchi, T.; Shimizu, K.; Miyanishi, K.; Terai, T.; Kakeshita, T.; Sakawa, Y.; Kodama, R.

2014-12-01

H2O is believed to be one of the most abundant compounds in ice giants including Neptune and Uranus1. Therefore, equation of state (EOS) for H2O is critical for understanding the formation and evolution of these planets. Various EOS models have been suggested for modeling the interior structure of the ice giants2-4. The recent shock experiments reported that their P - ρ data of H2O are in agreement with those of the QMD based EOS model5, indicating that this model is most suitable for modeling H2O in the ice giants. Whether H2O is in the solid or liquid state in the planetary interior has a great importance to understand their internal structures6. While the QMD model predicted that the solid H2O is present in deep interior of their planets above ~100 GPa4, the recent measurements revealed that H2O remains in the liquid state even at the deep interior conditions7. This discrepancy between experimental and theoretical studies suggests that the QMD based EOS model is disputable for modeling the planetary interior. Indeed, the comparison between data obtained from the shock experiments and the QMD based EOS did not cover the temperature5. We have obtained P - ρ - T data for H2O up to 260 GPa by using laser-driven shock compression technique. The diamond cell applied for the laser shock experiments was used as the sample container in order to achieve temperature conditions lower than the principal Hugoniot states. This shock technique combined with the cell can be used for an assessment the EOS models because it is possible to compare the states under the conditions that the contrast between the models clearly appears. Our data covering P - ρ - T on both the principal and the off Hugoniot curves agree with those of the QMD model, indicating this model to be adopted as the standard for modeling the interior structures of Neptune, Uranus, and exoplanets. References 1W. B. Hubbard et al., The interior of Neptune: Neptune and Triton(Univ. Arizona Press, Tucson, 1995) p.109-138. 2S. P. Lyon and J. D. Johnson, Los Alamos Technical Report No. LA-UR-92-3407, 1992. 3F. H. Ree, Lawrence Livemore Laboratory Technical Report No. UCRL-52190, 1976. 4M. French et al., Phys. Rev. B 79, 054107 (2009). 5M. D. Knudson et al., Phys. Rev. Lett. 108, 091102 (2012). 6 R. Redmer et al., Icarus 211, 798 (2011). 7T. Kimura et al., J. Chem. Phys. 140, 074501 (2014).

Future global crude oil supply

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

Ivanhoe, L.F.

Inexpensive crude oil fuels the world's economies and armies. In 1986, for the first time, the global production of crude oil and natural liquids exceeded new reserves added. Proved oil reserves at the end of 1985 stood 707.6 billion bbl (BBO), but declined to 703.1 BBO by the end of 1986. The 1986 reserve decrease, 4.5 BBO, was 20.4% of total global production of 22.0 BBO. This handwriting on the wall is very bad news. The world's recoverable crude oil and natural gas liquids discovered through 1985 totaled 1258 BBO, including cumulative production of 551 BBO and 707 BBO ofmore » reserves. At current production rates, half of all discovered oil will have been burned up by 1989. Timing of the end of our oil age can be extrapolated from a modified Hubbert curve, with future production resembling a mirror image of past production. The watershed beginning of the inevitable decline in global crude oil supplies can be expected in the late 1990s, although the date may be over 30 years later in some super-oily Organization of Petroleum Exporting Countries (OPEC). Clearly the day of reckoning will be postponed by any new oil discoveries. These will probably be distributed much as are the present global reserves (e.g., 68% OPEC; 11% USSR and China; 21% rest of world). Of this 56% will be in the Persian Gulf area. Giant fields (more than 0.5 BBO reserves) contain 75% of the world's reserves. Discoveries of oil in the globe's 320 known giant fields peaked at 125 BBO during the period 1961-1965, after which giant field discoveries plunged to only 10 BBO during 1981-1985. Henceforth, they should expect to find few giant whales (but many minnows) in the non-OPEC world's fished-out basins. Every new field will help as global crude oil supplies dwindle. Therefore, it is essential that all large prospects outside the Persian Gulf be tested promptly, so the oil-importing nations will known what size of non-OPEC reserves are available.« less

Influence of liquid phase on nanoparticle-based giant electrorheological fluid.

PubMed

Gong, Xiuqing; Wu, Jinbo; Huang, Xianxiang; Wen, Weijia; Sheng, Ping

2008-04-23

We show that the chemical structures of silicone oils can have an important role in the giant electrorheological (GER) effect. The interaction between silicone oils and solid nanoparticles is found to significantly influence the ER effect. By increasing the kinematic viscosity of silicone oils, which is a function of siloxane chain length, sol-like, gel-like and clay-like appearances of the constituted ER fluids were observed. Different functional-group-terminated silicone oils were also employed as the dispersing media. Significant differences of yield stress were found. We systematically study the effect of siloxane chain lengths on the permeability of oils traveling through the porous spaces between the particles (using the Washburn method), oils adsorbed on the particles' surface (using FT-IR spectra), as well as their particle size distribution (using dynamic light scattering). Our results indicate the hydrogen bonds are instrumental in linking the silicone oil to GER solid particles, and long chain lengths can enhance the agglomeration of the GER nanoparticles to form large clusters. An optimal oil structure, with hydroxyl-terminated silicone oil and a suitable viscosity, was chosen which can create the highest yield stress of ∼300 kPa under a 5 kV mm(-1) DC electric field.

Crop advisor perceptions of giant ragweed distribution, herbicide-resistance, and management in the Corn Belt

USDA-ARS?s Scientific Manuscript database

Giant ragweed has been increasing as a major weed of row crops in North America. We conducted a web-based survey of Certified Crop Advisors in the Corn Belt to determine the current distribution of giant ragweed, the distribution of herbicide resistant populations, and management and ecological fact...

Topologically Diverse Human Membrane Proteins Partition to Liquid-Disordered Domains in Phase-Separated Lipid Vesicles.

PubMed

Schlebach, Jonathan P; Barrett, Paul J; Day, Charles A; Kim, Ji Hun; Kenworthy, Anne K; Sanders, Charles R

2016-02-23

The integration of membrane proteins into "lipid raft" membrane domains influences many biochemical processes. The intrinsic structural properties of membrane proteins are thought to mediate their partitioning between membrane domains. However, whether membrane topology influences the targeting of proteins to rafts remains unclear. To address this question, we examined the domain preference of three putative raft-associated membrane proteins with widely different topologies: human caveolin-3, C99 (the 99 residue C-terminal domain of the amyloid precursor protein), and peripheral myelin protein 22. We find that each of these proteins are excluded from the ordered domains of giant unilamellar vesicles containing coexisting liquid-ordered and liquid-disordered phases. Thus, the intrinsic structural properties of these three topologically distinct disease-linked proteins are insufficient to confer affinity for synthetic raft-like domains.

A DEFINITION FOR GIANT PLANETS BASED ON THE MASS–DENSITY RELATIONSHIP

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

Hatzes, Artie P.; Rauer, Heike, E-mail: artie@tls-tautenburg.de, E-mail: Heike.Rauer@dlr.de

We present the mass–density relationship (log M − log ρ) for objects with masses ranging from planets (M ≈ 0.01 M{sub Jup}) to stars (M > 0.08 M{sub ⊙}). This relationship shows three distinct regions separated by a change in slope in the log M − log ρ plane. In particular, objects with masses in the range 0.3 M{sub Jup}–60 M{sub Jup} follow a tight linear relationship with no distinguishing feature to separate the low-mass end (giant planets) from the high-mass end (brown dwarfs). We propose a new definition of giant planets simply based on changes in the slope ofmore » the log M versus log ρ relationship. By this criterion, objects with masses less than ≈0.3 M{sub Jup} are low-mass planets, either icy or rocky. Giant planets cover the mass range 0.3 M{sub Jup}–60 M{sub Jup}. Analogous to the stellar main sequence, objects on the upper end of the giant planet sequence (brown dwarfs) can simply be referred to as “high-mass giant planets,” while planets with masses near that of Jupiter can be called “low-mass giant planets.”.« less

Analysis of the cytochrome c oxidase subunit 1 (COX1) gene reveals the unique evolution of the giant panda.

PubMed

Hu, Yao-Dong; Pang, Hui-Zhong; Li, De-Sheng; Ling, Shan-Shan; Lan, Dan; Wang, Ye; Zhu, Yun; Li, Di-Yan; Wei, Rong-Ping; Zhang, He-Min; Wang, Cheng-Dong

2016-11-05

As the rate-limiting enzyme of the mitochondrial respiratory chain, cytochrome c oxidase (COX) plays a crucial role in biological metabolism. "Living fossil" giant panda (Ailuropoda melanoleuca) is well-known for its special bamboo diet. In an effort to explore functional variation of COX1 in the energy metabolism behind giant panda's low-energy bamboo diet, we looked at genetic variation of COX1 gene in giant panda, and tested for its selection effect. In 1545 base pairs of the gene from 15 samples, 9 positions were variable and 1 mutation leaded to an amino acid sequence change. COX1 gene produces six haplotypes, nucleotide (pi), haplotype diversity (Hd). In addition, the average number of nucleotide differences (k) is 0.001629±0.001036, 0.8083±0.0694 and 2.517, respectively. Also, dN/dS ratio is significantly below 1. These results indicated that giant panda had a low population genetic diversity, and an obvious purifying selection of the COX1 gene which reduces synthesis of ATP determines giant panda's low-energy bamboo diet. Phylogenetic trees based on the COX1 gene were constructed to demonstrate that giant panda is the sister group of other Ursidae. Copyright © 2016 Elsevier B.V. All rights reserved.

Spectral Flattening at Low Frequencies in Crab Giant Pulses

NASA Astrophysics Data System (ADS)

Meyers, B. W.; Tremblay, S. E.; Bhat, N. D. R.; Shannon, R. M.; Kirsten, F.; Sokolowski, M.; Tingay, S. J.; Oronsaye, S. I.; Ord, S. M.

2017-12-01

We report on simultaneous wideband observations of Crab giant pulses with the Parkes radio telescope and the Murchison Widefield Array (MWA). The observations were conducted simultaneously at 732 and 3100 MHz with Parkes and at 120.96, 165.76, and 210.56 MHz with the MWA. Flux density calibration of the MWA data was accomplished using a novel technique based on tied-array beam simulations. We detected between 90 and 648 giant pulses in the 120.96-210.56 MHz MWA subbands above a 5.5σ threshold, while in the Parkes subbands we detected 6344 and 231 giant pulses above a threshold of 6σ at 732 and 3100 MHz, respectively. We show, for the first time over a wide frequency range, that the average spectrum of Crab giant pulses exhibits a significant flattening at low frequencies. The spectral index, α, for giant pulses evolves from a steep, narrow distribution with a mean α =-2.6 and width {σ }α =0.5 between 732 and 3100 MHz to a wide, flat distribution of spectral indices with a mean α =-0.7 and width {σ }α =1.4 between 120.96 and 165.76 MHz. We also comment on the plausibility of giant pulse models for fast radio bursts based on this spectral information.

Genome-wide survey and analysis of microsatellites in giant panda (Ailuropoda melanoleuca), with a focus on the applications of a novel microsatellite marker system.

PubMed

Huang, Jie; Li, Yu-Zhi; Du, Lian-Ming; Yang, Bo; Shen, Fu-Jun; Zhang, He-Min; Zhang, Zhi-He; Zhang, Xiu-Yue; Yue, Bi-Song

2015-02-07

The giant panda (Ailuropoda melanoleuca) is a critically endangered species endemic to China. Microsatellites have been preferred as the most popular molecular markers and proven effective in estimating population size, paternity test, genetic diversity for the critically endangered species. The availability of the giant panda complete genome sequences provided the opportunity to carry out genome-wide scans for all types of microsatellites markers, which now opens the way for the analysis and development of microsatellites in giant panda. By screening the whole genome sequence of giant panda in silico mining, we identified microsatellites in the genome of giant panda and analyzed their frequency and distribution in different genomic regions. Based on our search criteria, a repertoire of 855,058 SSRs was detected, with mono-nucleotides being the most abundant. SSRs were found in all genomic regions and were more abundant in non-coding regions than coding regions. A total of 160 primer pairs were designed to screen for polymorphic microsatellites using the selected tetranucleotide microsatellite sequences. The 51 novel polymorphic tetranucleotide microsatellite loci were discovered based on genotyping blood DNA from 22 captive giant pandas in this study. Finally, a total of 15 markers, which showed good polymorphism, stability, and repetition in faecal samples, were used to establish the novel microsatellite marker system for giant panda. Meanwhile, a genotyping database for Chengdu captive giant pandas (n = 57) were set up using this standardized system. What's more, a universal individual identification method was established and the genetic diversity were analysed in this study as the applications of this marker system. The microsatellite abundance and diversity were characterized in giant panda genomes. A total of 154,677 tetranucleotide microsatellites were identified and 15 of them were discovered as the polymorphic and stable loci. The individual identification method and the genetic diversity analysis method in this study provided adequate material for the future study of giant panda.

Reactor vibration reduction based on giant magnetostrictive materials

NASA Astrophysics Data System (ADS)

Rongge, Yan; Weiying, Liu; Yuechao, Wu; Menghua, Duan; Xiaohong, Zhang; Lihua, Zhu; Ling, Weng; Ying, Sun

2017-05-01

The vibration of reactors not only produces noise pollution, but also affects the safe operation of reactors. Giant magnetostrictive materials can generate huge expansion and shrinkage deformation in a magnetic field. With the principle of mutual offset between the giant magnetostrictive force produced by the giant magnetostrictive material and the original vibration force of the reactor, the vibration of the reactor can be reduced. In this paper, magnetization and magnetostriction characteristics in silicon steel and the giant magnetostrictive material are measured, respectively. According to the presented magneto-mechanical coupling model including the electromagnetic force and the magnetostrictive force, reactor vibration is calculated. By comparing the vibration of the reactor with different inserted materials in the air gaps between the reactor cores, the vibration reduction effectiveness of the giant magnetostrictive material is validated.

Turbulent convection in liquid metal with and without rotation.

PubMed

King, Eric M; Aurnou, Jonathan M

2013-04-23

The magnetic fields of Earth and other planets are generated by turbulent, rotating convection in liquid metal. Liquid metals are peculiar in that they diffuse heat more readily than momentum, quantified by their small Prandtl numbers, Pr < 1. Most analog models of planetary dynamos, however, use moderate Pr fluids, and the systematic influence of reducing Pr is not well understood. We perform rotating Rayleigh-Bénard convection experiments in the liquid metal gallium (Pr = 0.025) over a range of nondimensional buoyancy forcing (Ra) and rotation periods (E). Our primary diagnostic is the efficiency of convective heat transfer (Nu). In general, we find that the convective behavior of liquid metal differs substantially from that of moderate Pr fluids, such as water. In particular, a transition between rotationally constrained and weakly rotating turbulent states is identified, and this transition differs substantially from that observed in moderate Pr fluids. This difference, we hypothesize, may explain the different classes of magnetic fields observed on the Gas and Ice Giant planets, whose dynamo regions consist of Pr < 1 and Pr > 1 fluids, respectively.

Water in the world

USGS Publications Warehouse

Leopold, Luna Bergere

1964-01-01

The earth, Including Its oceans and atmosphere, ls a giant distillation system whose operation brings about the distribution of fresh water throughout the world, from the frozen wastes of polar regions to the burning equatorial deserts. Stated in the simplest terms, distillation, condensation and liquid flow are the elemental processes which, on a grand scale, distribute and circulate throughout the world the water which ls essential for all life.Water in liquid form absorbs heat energy, chiefly from the sun, and the absorbed energy changes the water from liquid to gaseous form. Transported in the atmosphere, the vapour later meets cooler conditions and condenses as precipitation, some of which replenishes the water in land areas.Because water is continually being transformed from liquid to vapour and back to liquid again, the whole sequence of events ends where It began. That ls, the condensed moisture in the form of precipitation runs Into or off the surface of the earth, and a part of It collects in rivers which flow to the ocean. The events together form what is called the hydrological cycle.

WIYN Open Cluster Study. LXXVI. Li Evolution Among Stars of Low/Intermediate Mass: The Metal-deficient Open Cluster NGC 2506

NASA Astrophysics Data System (ADS)

Anthony-Twarog, Barbara J.; Lee-Brown, Donald B.; Deliyannis, Constantine P.; Twarog, Bruce A.

2018-03-01

HYDRA spectra of 287 stars in the field of NGC 2506 from the turnoff through the giant branch are analyzed. With previous data, 22 are identified as probable binaries; 90 more are classified as potential non-members. Spectroscopic analyses of ∼60 red giants and slowly rotating turnoff stars using line equivalent widths and a neural network approach lead to [Fe/H] = ‑0.27 ± 0.07 (s.d.) and [Fe/H] = ‑0.27 ± 0.06 (s.d.), respectively. Li abundances are derived for 145 probable single-star members, 44 being upper limits. Among turnoff stars outside the Li-dip, A(Li) = 3.04 ± 0.16 (s.d.), with no trend with color, luminosity, or rotation speed. Evolving from the turnoff across the subgiant branch, there is a well-delineated decline to A(Li) ∼1.25 at the giant branch base, coupled with the rotational spindown from between ∼20 and 70 km s‑1 to less than 20 km s‑1 for stars entering the subgiant branch and beyond. A(Li) remains effectively constant from the giant branch base to the red giant clump level. A new member above the clump redefines the path of the first-ascent red giant branch; its Li is 0.6 dex below the first-ascent red giants. With one exception, all post-He-flash stars have upper limits to A(Li), at or below the level of the brightest first-ascent red giant. The patterns are in excellent qualitative agreement with the model predictions for low/intermediate-mass stars which undergo rotation-induced mixing at the turnoff and subgiant branch, first dredge-up, and thermohaline mixing beyond the red giant bump.

Freezing Nitrogen Ethanol Composite May be a Viable Approach for Cryotherapy of Human Giant Cell Tumor of Bone.

PubMed

Wu, Po-Kuei; Chen, Cheng-Fong; Wang, Jir-You; Chen, Paul Chih-Hsueh; Chang, Ming-Chau; Hung, Shih-Chieh; Chen, Wei-Ming

2017-06-01

Liquid nitrogen has been used as adjuvant cryotherapy for treating giant cell tumor (GCT) of bone. However, the liquid phase and ultrafreezing (-196° C) properties increase the risk of damage to the adjacent tissues and may lead to perioperative complications. A novel semisolid cryogen, freezing nitrogen ethanol composite, might mitigate these shortcomings because of less-extreme freezing. We therefore wished to evaluate freezing nitrogen ethanol composite as a coolant to determine its properties in tumor cryoablation. (1) Is freezing nitrogen ethanol composite-mediated freezing effective for tumor cryoablation in an ex vivo model, and if yes, is apoptosis involved in the tumor-killing mechanism? (2) Does freezing nitrogen ethanol composite treatment block neovascularization and neoplastic progression of the grafted GCTs and is it comparable to that of liquid nitrogen in an in vivo chicken model? (3) Can use of freezing nitrogen ethanol composite as an adjuvant to curettage result in successful short-term treatment, defined as absence of GCT recurrence at a minimum of 1 year in a small proof-of-concept clinical series? The cryogenic effect on bone tissue mediated by freezing nitrogen ethanol composite and liquid nitrogen was verified by thermal measurement in a time-course manner. Cryoablation on human GCT tissue was examined ex vivo for effect on morphologic features (cell shrinkage) and DNA fragmentation (apoptosis). The presumed mechanism was investigated by molecular analysis of apoptosis regulatory proteins including caspases 3, 8, and 9 and Bax/Bcl-2. Chicken chorioallantoic membrane was used as an in vivo model to evaluate the effects of freezing nitrogen ethanol composite and liquid nitrogen treatment on GCT-derived neovascularization and tumor neoplasm. A small group of patients with GCT of bone was treated by curettage and adjuvant freezing nitrogen ethanol composite cryotherapy in a proof-of-concept study. Tumor recurrence and perioperative complications were evaluated at a minimum of 19 months followup (mean, 24 months; range, 19-30 months). Freshly prepared freezing nitrogen ethanol composite froze to -136° C and achieved -122° C isotherm across a piece of 10 ± 0.50-mm-thick bone with a freezing rate of -34° C per minute, a temperature expected to meet clinical tumor-killing requirements. Human GCT tissues revealed histologic changes including shrinkage in morphologic features of multinucleated giant cells in the liquid nitrogen (202 ± 45 μm; p = 0.006) and freezing nitrogen ethanol composite groups (169 ± 27.4 μm; p < 0.001), and a decreased nucleated area of neoplastic stromal cells for the 30-second treatment. Enhanced counts of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells verified the involvement of DNA fragmentation in cryoablated GCT tissues. Western blotting analysis on the expression of apoptosis regulatory proteins showed enhancement of proteocleavage-activated caspases 3, 8, and 9 and higher ratios of Bax/Bcl2 in the liquid nitrogen- and freezing nitrogen ethanol composite-treated samples. Numbers of blood vessels and human origin tumor cells also were decreased by freezing nitrogen ethanol composite and liquid nitrogen treatment in the GCT-grafted chicken chorioallantoic membrane model. Seven patients with GCT treated by curettage and adjuvant cryotherapy by use of freezing nitrogen ethanol composite preparation had no intra- or postoperative complications related to the freezing, and no recurrences during the study surveillance period. These preliminary in vitro and clinical findings suggest that freezing nitrogen ethanol composite may be an effective cryogen showing ex vivo and in vivo tumor cryoablation comparable to liquid nitrogen. The semisolid phase and proper thermal conduction might avoid some of the disadvantages of liquid nitrogen in cryotherapy, but a larger clinical study is needed to confirm these findings. Level IV, therapeutic study.

The minimum area requirements (MAR) for giant panda: an empirical study

PubMed Central

Qing, Jing; Yang, Zhisong; He, Ke; Zhang, Zejun; Gu, Xiaodong; Yang, Xuyu; Zhang, Wen; Yang, Biao; Qi, Dunwu; Dai, Qiang

2016-01-01

Habitat fragmentation can reduce population viability, especially for area-sensitive species. The Minimum Area Requirements (MAR) of a population is the area required for the population’s long-term persistence. In this study, the response of occupancy probability of giant pandas against habitat patch size was studied in five of the six mountain ranges inhabited by giant panda, which cover over 78% of the global distribution of giant panda habitat. The probability of giant panda occurrence was positively associated with habitat patch area, and the observed increase in occupancy probability with patch size was higher than that due to passive sampling alone. These results suggest that the giant panda is an area-sensitive species. The MAR for giant panda was estimated to be 114.7 km2 based on analysis of its occupancy probability. Giant panda habitats appear more fragmented in the three southern mountain ranges, while they are large and more continuous in the other two. Establishing corridors among habitat patches can mitigate habitat fragmentation, but expanding habitat patch sizes is necessary in mountain ranges where fragmentation is most intensive. PMID:27929520

The minimum area requirements (MAR) for giant panda: an empirical study.

PubMed

Qing, Jing; Yang, Zhisong; He, Ke; Zhang, Zejun; Gu, Xiaodong; Yang, Xuyu; Zhang, Wen; Yang, Biao; Qi, Dunwu; Dai, Qiang

2016-12-08

Habitat fragmentation can reduce population viability, especially for area-sensitive species. The Minimum Area Requirements (MAR) of a population is the area required for the population's long-term persistence. In this study, the response of occupancy probability of giant pandas against habitat patch size was studied in five of the six mountain ranges inhabited by giant panda, which cover over 78% of the global distribution of giant panda habitat. The probability of giant panda occurrence was positively associated with habitat patch area, and the observed increase in occupancy probability with patch size was higher than that due to passive sampling alone. These results suggest that the giant panda is an area-sensitive species. The MAR for giant panda was estimated to be 114.7 km 2 based on analysis of its occupancy probability. Giant panda habitats appear more fragmented in the three southern mountain ranges, while they are large and more continuous in the other two. Establishing corridors among habitat patches can mitigate habitat fragmentation, but expanding habitat patch sizes is necessary in mountain ranges where fragmentation is most intensive.

Role of nature reserves in giant panda protection.

PubMed

Kang, Dongwei; Li, Junqing

2018-02-01

Giant panda (Ailuropoda melanoleuca) is a flagship species in nature conservation of the world; to protect this species, 67 nature reserves have been established in China. To evaluate the protection effect of giant panda nature reserves, we analyzed the variation of giant panda number and habitat area of 23 giant panda nature reserves of Sichuan province based on the national survey data released by State Forestry Administration and Sichuan Forestry Department. Results showed that from the third national survey to the fourth, giant panda number and habitat area of 23 giant panda nature reserves of Sichuan province failed to realize the significant increase. Furthermore, we found that the total population growth rate of 23 nature reserves in the last 12 years was lower than those of the province total of Sichuan and the national total of China, and the total habitat area of the 23 nature reserves was decreasing in the last 12 years, but the province total and national total were all increasing. We propose that giant panda protection should pay more attention to how to improve the protective effects of nature reserves.

Design, Synthesis, and Self-Assembly of Well-Defined Hybrid Materials Including Polymer Amphiphiles and Giant Tetrahedra Molecules Based on Poss Nanoparticles

NASA Astrophysics Data System (ADS)

Huang, Mingjun

"Bottom-up" techniques-based self-assembly are always attracting people's interests since this technology provides relatively low economic cost and fast route to construct organized structures at different scales. Considering unprecedented benefits from polymer materials, self-assemblies utilizing polymer building blocks have been extensively studied to achieve diverse hierarchical structures and various attractive properties. However, precise controls of chemical primary structures and compositions and exact constructions of hierarchal ordered structures in synthetic polymers are far from being fully appreciated. In this dissertation, a novel approach has been utilized to construct diverse well-defined nano-building blocks, giant molecules, via conjugating different, and functionalized molecular nanoparticles (MNPs) which are shape- and volume-persistent nano-objects with precise molecular structure and specific symmetry. The representative examples of the three basic categories of giant molecules, "giant polyhedra", "giant surfactants", and "giant shape amphiphiles" were discussed in details. First, a class of precisely defined, nanosized giant tetrahedra was constructed by placing different polyhedral oligomeric silsesquioxane (POSS) molecular nanoparticles at the vertices of a rigid tetrahedral framework. Designed symmetry breaking of these giant tetrahedra introduces accurate positional interactions and results in diverse selectively assembled, highly ordered supramolecular lattices including a Frank-Kasper (FK) A15 phase. The FK and quasicrystal phases are originally identified in metal alloys and only sporadically observed in soft matters. It remains unclear how to correlate their stability with the chemical composition and molecular topology in the self-assembling systems. We then for this purpose designed and studied the self-assembly phase transition sequences of four series of hybrid giant surfactants based on hydrophilic POSS cages tethered with one to four polystyrene (PS) tails. With increasing the number of tails, molecular topological variations not only affect phase boundaries in terms of the PS volume fraction, but also open a window to stabilize supramolecular FK and quasicrystal phases in the spherical phase region, demonstrating the critical role of molecular topology in dictating the formation of unconventional supramolecular lattices of "soft" spherical motifs. The FK A15 phase was even surprisingly observed in the giant shape amphiphile molecule, triphenylene-6BPOSS, which has a disk-like flat triphenylene core connected with six hydrophobic POSS cages by sides. Without conical molecular shape, triphenylene-6BPOSS self-assembled and stabilized into supramolecular sphere via pi-pi interactions through a completely different mechanism with precious two cases. These studies indicate that "bottom-up" self-assemble based on well-defined giant molecules approach can be rather powerful to fabricate usually complicated hierarchical structures and open up a wide field of supramolecular self-assembly with unexpected structure and properties.

Analysis of the breast milk of giant pandas (Ailuropoda melanoleuca) and the preparation of substitutes

PubMed Central

ZHANG, Zhihe; HOU, Rong; LAN, Jingchao; WANG, Hairui; KUROKAWA, Hiroyuki; TAKATSU, Zenta; KOBAYASHI, Toyokazu; KOIE, Hiroshi; KAMATA, Hiroshi; KANAYAMA, Kiichi; WATANABE, Toshi

2016-01-01

The first milk substitute for giant panda cubs was developed in 1988 based on limited data about giant panda breast milk and that of certain types of bear. Mixtures of other formulas have also been fed to cubs at some facilities. However, they are not of sufficient nutritional quality for promoting growth in panda cubs. Here, we report analysis of giant panda breast milk and propose new milk substitutes for cubs, which were developed based on the results of our analysis. The Chengdu Research Base of Giant Panda Breeding obtained breast milk samples from three giant pandas. Up to 30 ml of breast milk were collected from each mother by hand. Then, the milk samples were frozen and sent to Nihon University. The levels of protein, fat, carbohydrates, ash, moisture, vitamins, minerals, total amino acids, fatty acids, lactose and other carbohydrates in the milk were analyzed. The breast milk samples exhibited the following nutritional values: protein: 6.6–8.5%, fat: 6.9–16.4%, carbohydrates: 2.5–9.1%, ash: 0.9–1.0% and moisture: 67–83%. We designed two kinds of milk substitutes based on the data obtained and the nutritional requirements of dogs, cats and rodents. The nutritional composition of the milk substitutes for the first and second stages was as follows: protein: 38 and 26%, fat: 40 and 40%, carbohydrates: 13 and 25%, ash: 6 and 6% and moisture: 3 and 3%, respectively. In addition, the substitutes contained vitamins, minerals, taurine, docosahexaenoic acid, lactoferrin, nucleotides and other nutrients. PMID:26781707

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

Snezhko, Alex and Aronson, Igor

Nickel particles float peacefully in a liquid medium until a giant snake seems to swim by and snatch several particles up, adding to its own mass. The self-assembled "snakes" act like biological systems, but they are not alive and are driven by a magnetic field. The research may someday offer some insight into the organization of life itself. Read more at Wired: http://www.wired.com/wiredscience/2009/03/snakes/. Research and video by Alex Snezhko and Igor Aronson, Argonne National Laboratory.

Dislocation Structure and Mobility in hcp He 4

DOE PAGES

Landinez Borda, Edgar Josue; Cai, Wei; de Koning, Maurice

2016-07-20

We assess the core structure and mobility of the screw and edge basal-plane dislocations in hcp 4He using path-integral Monte Carlo simulations. Our findings provide key insights into recent interpretations of giant plasticity and mass flow junction experiments. First, both dislocations are dissociated into nonsuperfluid Shockley partial dislocations separated by ribbons of stacking fault, suggesting that they are unlikely to act as one-dimensional channels that may display Lüttinger-liquid-like behavior. Second, the centroid positions of the partial cores are found to fluctuate substantially, even in the absence of applied shear stresses. This implies that the lattice resistance to motion of themore » partial dislocations is negligible, consistent with the recent experimental observations of giant plasticity. Our results indicate that both the structure of the partial cores and the zero-point fluctuations play a role in this extreme mobility.« less

Titan under a red giant sun: a new kind of "habitable" moon.

PubMed

Lorenz, R D; Lunine, J I; McKay, C P

1997-11-15

We explore the response of Titan's surface and massive atmosphere to the change in solar spectrum and intensity as the sun evolves into a red giant. Titan's surface temperature is insensitive to insolation increases as the haze-laden atmosphere "puffs up" and blocks more sunlight. However, we find a window of several hundred Myr exists, roughly 6 Gyr from now, when liquid water-ammonia can form oceans on the surface and react with the abundant organic compounds there. The window opens due to a drop in haze production as the ultraviolet flux from the reddening sun plummets. The duration of such a window exceeds the time necessary for life to have begun on Earth. Similar environments, with approximately 200K water-ammonia oceans warmed by methane greenhouses under red stars, are an alternative to the approximately 30OK water-CO2 environments considered the classic "habitable" planet.

TRAP-Positive Multinucleated Giant Cells Are Foreign Body Giant Cells Rather Than Osteoclasts: Results From a Split-Mouth Study in Humans.

PubMed

Lorenz, Jonas; Kubesch, Alica; Korzinskas, Tadas; Barbeck, Mike; Landes, Constantin; Sader, Robert A; Kirkpatrick, Charles J; Ghanaati, Shahram

2015-12-01

This study compared the material-specific tissue response to the synthetic, hydroxyapatite-based bone substitute material NanoBone (NB) with that of the xenogeneic, bovine-based bone substitute material Bio-Oss (BO). The sinus cavities of 14 human patients were augmented with NB and BO in a split-mouth design. Six months after augmentation, bone biopsies were extracted for histological and histomorphometric investigation prior to dental implant insertion. The following were evaluated: the cellular inflammatory pattern, the induction of multinucleated giant cells, vascularization, the relative amounts of newly formed bone, connective tissue, and the remaining bone substitute material. NB granules were well integrated in the peri-implant tissue and were surrounded by newly formed bone tissue. Multinucleated giant cells were visible on the surfaces of the remaining granules. BO granules were integrated into the newly formed bone tissue, which originated from active osteoblasts on their surface. Histomorphometric analysis showed a significantly higher number of multinucleated giant cells and blood vessels in the NB group compared to the BO group. No statistical differences were observed in regard to connective tissue, remaining bone substitute, and newly formed bone. The results of this study highlight the different cellular reactions to synthetic and xenogeneic bone substitute materials. The significantly higher number of multinucleated giant cells within the NB implantation bed seems to have no effect on its biodegradation. Accordingly, the multinucleated giant cells observed within the NB implantation bed have characteristics more similar to those of foreign body giant cells than to those of osteoclasts.

Low Mach number fluctuating hydrodynamics of multispecies liquid mixtures

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

Donev, Aleksandar, E-mail: donev@courant.nyu.edu; Bhattacharjee, Amit Kumar; Nonaka, Andy

We develop a low Mach number formulation of the hydrodynamic equations describing transport of mass and momentum in a multispecies mixture of incompressible miscible liquids at specified temperature and pressure, which generalizes our prior work on ideal mixtures of ideal gases [Balakrishnan et al., “Fluctuating hydrodynamics of multispecies nonreactive mixtures,” Phys. Rev. E 89 013017 (2014)] and binary liquid mixtures [Donev et al., “Low mach number fluctuating hydrodynamics of diffusively mixing fluids,” Commun. Appl. Math. Comput. Sci. 9(1), 47-105 (2014)]. In this formulation, we combine and extend a number of existing descriptions of multispecies transport available in the literature. Themore » formulation applies to non-ideal mixtures of arbitrary number of species, without the need to single out a “solvent” species, and includes contributions to the diffusive mass flux due to gradients of composition, temperature, and pressure. Momentum transport and advective mass transport are handled using a low Mach number approach that eliminates fast sound waves (pressure fluctuations) from the full compressible system of equations and leads to a quasi-incompressible formulation. Thermal fluctuations are included in our fluctuating hydrodynamics description following the principles of nonequilibrium thermodynamics. We extend the semi-implicit staggered-grid finite-volume numerical method developed in our prior work on binary liquid mixtures [Nonaka et al., “Low mach number fluctuating hydrodynamics of binary liquid mixtures,” http://arxiv.org/abs/1410.2300 (2015)] and use it to study the development of giant nonequilibrium concentration fluctuations in a ternary mixture subjected to a steady concentration gradient. We also numerically study the development of diffusion-driven gravitational instabilities in a ternary mixture and compare our numerical results to recent experimental measurements [Carballido-Landeira et al., “Mixed-mode instability of a miscible interface due to coupling between Rayleigh–Taylor and double-diffusive convective modes,” Phys. Fluids 25, 024107 (2013)] in a Hele-Shaw cell. We find that giant nonequilibrium fluctuations can trigger the instability but are eventually dominated by the deterministic growth of the unstable mode, in both quasi-two-dimensional (Hele-Shaw) and fully three-dimensional geometries used in typical shadowgraph experiments.« less

Should the Endangered Status of the Giant Panda Really Be Reduced? The Case of Giant Panda Conservation in Sichuan, China.

PubMed

Ma, Ben; Lei, Shuo; Qing, Qin; Wen, Yali

2018-05-03

The International Union for Conservation of Nature (IUCN) reduced the threat status of the giant panda from “endangered” to “vulnerable” in September 2016. In this study, we analyzed current practices for giant panda conservation at regional and local environmental scales, based on recent reports of giant panda protection efforts in Sichuan Province, China, combined with the survey results from 927 households within and adjacent to the giant panda reserves in this area. The results showed that household attitudes were very positive regarding giant panda protection efforts. Over the last 10 years, farmers’ dependence on the natural resources provided by giant panda reserves significantly decreased. However, socio-economic development increased resource consumption, and led to climate change, habitat fragmentation, environmental pollution, and other issues that placed increased pressure on giant panda populations. This difference between local and regional scales must be considered when evaluating the IUCN status of giant pandas. While the status of this species has improved in the short-term due to positive local attitudes, large-scale socio-economic development pressure could have long-term negative impacts. Consequently, the IUCN assessment leading to the classification of giant panda as “vulnerable” instead of “endangered”, should not affect its conservation intensity and effort, as such actions could negatively impact population recovery efforts, leading to the extinction of this charismatic species.

Extremely metal-deficient red giants. IV - Equivalent widths for 36 halo giants

NASA Technical Reports Server (NTRS)

Luck, R. E.; Bond, H. E.

1985-01-01

Further work on a study of 36 metal-poor field red giants is reported. Chemical abundances previously determined were based on model stellar atmosphere analyses of equivalent widths from photographic image-tube echelle spectrograms obtained with with 4-m reflectors at Kitt Peak and Cerro Tololo. A tabulation of the equivalent-width data (a total of 18, 275 equivalent widths) is presented.

Scientific opportunities at SARAF with a liquid lithium jet target neutron source

NASA Astrophysics Data System (ADS)

Silverman, Ido; Arenshtam, Alex; Berkovits, Dan; Eliyahu, Ilan; Gavish, Inbal; Grin, Asher; Halfon, Shlomi; Hass, Michael; Hirsh, T. Y.; Kaizer, Boaz; Kijel, Daniel; Kreisel, Arik; Mardor, Israel; Mishnayot, Yonatan; Palchan, Tala; Perry, Amichay; Paul, Michael; Ron, Guy; Shimel, Guy; Shor, Asher; Tamim, Noam; Tessler, Moshe; Vaintraub, Sergey; Weissman, Leo

2018-05-01

SARAF (Soreq Applied Research Accelerator Facility) is based on a 5 mA, 40 MeV, proton/deuteron accelerator. Phase-I, operational since 2010, provides proton and deuteron beams up to 4 and 5 MeV, respectively, for basic and applied research activities. The high power Liquid-Lithium jet Target (LiLiT), with 1.912 MeV proton beam, provides high flux quasi-Maxwellian neutrons at kT 30 keV (about 2 × 1010 n/s/cm2/mA on the irradiated sample, about 1 cm from the target), enabling studies of s-process reactions relevant to nucleo-synthesis of the heavy elements in giant AGB stars. With higher energy proton beams and with deuterons, LiLiT can provide higher fluxes of high energy neutrons up to 20 MeV. The experimental program with SARAF phase-I will be enhanced shortly with a new target room complex which is under construction. Finally, SARAF phase-II, planned to start operation at 2023, will enable full capabilities with proton/ deuteron beams at 5 mA and 40 MeV. Liquid lithium targets will then be used to produce neutron sources with intensities of 1015 n/s, which after thermalization will provide thermal neutron (25 meV) fluxes of about 1012 n/s/cm2 at the entrance to neutron beam lines to diffraction and radiography stations.

Giant pandas can discriminate the emotions of human facial pictures.

PubMed

Li, Youxu; Dai, Qiang; Hou, Rong; Zhang, Zhihe; Chen, Peng; Xue, Rui; Feng, Feifei; Chen, Chao; Liu, Jiabin; Gu, Xiaodong; Zhang, Zejun; Qi, Dunwu

2017-08-16

Previous studies have shown that giant pandas (Ailuropoda melanoleuca) can discriminate face-like shapes, but little is known about their cognitive ability with respect to the emotional expressions of humans. We tested whether adult giant pandas can discriminate expressions from pictures of half of a face and found that pandas can learn to discriminate between angry and happy expressions based on global information from the whole face. Young adult pandas (5-7 years old) learned to discriminate expressions more quickly than older individuals (8-16 years old), but no significant differences were found between females and males. These results suggest that young adult giant pandas are better at discriminating emotional expressions of humans. We showed for the first time that the giant panda, can discriminate the facial expressions of humans. Our results can also be valuable for the daily care and management of captive giant pandas.

Mechanical model of giant photoexpansion in a chalcogenide glass and the role of photofluidity

NASA Astrophysics Data System (ADS)

Buisson, Manuel; Gueguen, Yann; Laniel, Romain; Cantoni, Christopher; Houizot, Patrick; Bureau, Bruno; Sangleboeuf, Jean-Christophe; Lucas, Pierre

2017-07-01

An analytical model is developed to describe the phenomenon of giant photoexpansion in chalcogenide glasses. The proposed micro-mechanical model is based on the description of photoexpansion as a new type of eigenstrain, i.e. a deformation analogous to thermal expansion induced without external forces. In this framework, it is the viscoelastic flow induced by photofluidity which enable the conversion of the self-equilibrated stress into giant photoexpansion. This simple approach yields good fits to experimental data and demonstrates, for the first time, that the photoinduced viscous flow actually enhances the giant photoexpansion or the giant photocontraction as it has been suggested in the literature. Moreover, it highlights that the shear relaxation time due to photofluidity controls the expansion kinetic. This model is the first step towards describing giant photoexpansion from the point of view of mechanics and it provides the framework for investigating this phenomenon via numerical simulations.

Oxygen abundances in halo giants. I - Giants in the very metal-poor globular clusters M92 and M15 and the metal-poor halo field

NASA Astrophysics Data System (ADS)

Sneden, Christopher; Kraft, Robert P.; Prosser, Charles F.; Langer, G. E.

1991-12-01

Oxygen, iron, vanadium, and scandium abundances are derived for very metal-poor giants in the globular clusters M92 and M15, and giants of comparable metallicity in the local halo field. The forbidden O I line dublet (6300, 6363) and nearby metallic lines in spectra are analyzed using line analysis and spectral synthesis codes. The Fe/H abundance for M92 is estimated at -2.25 +/-0.02 based on nine giants with a range of 500 K in effective temperature. No evidence for star-to-star variations in the Fe/H abundance was found. O-rich and O-poor stars appear intermixed in the H-R diagram. O - N nuclear synthesis and mixing to the surface are proposed as the best explanation for the low-oxygen giants. The nitrogen abundances obtained earlier for nine of the ten halo field giants in this sample are incompatible with the very large nitrogen abundances expected of the O/Fe abundance of about + 1.2 in halo field subdwarfs, as found by Abia and Rebolo (1989), and not more than 0.6 in halo giants, as found in this and other studies.

Molten silicate mantle during a giant impact. Speciation from vapor to supercritical state

NASA Astrophysics Data System (ADS)

Caracas, R.; Stewart, S. T.

2017-12-01

We employ large-scale first-principles molecular dynamics simulations to understand the physical and chemical behavior of the molten protolunar disk, at the atomic level. We consider the average composition of the Earth's mantle as proposed by Sun and McDonough (1995). We cover the 0.75 - 7.5 g/cm3 density range and 2000 - 10000 K temperature range. This allows us to investigate the entire disk, from the interior of the molten core to the outer regions of the vaporized disk. At high density, the liquid is highly polymerized and viscous, consistent with previous studies. At low density and low temperatures, in the 2000 to 4000 K range, we capture the nucleation of bubbles. The bubbles contain a low-density gas phase rich in individual alkaline and calc-alkaline cations and SiOx groups. When volatiles are present in the system, such molecular species are the first ones to evaporate and be present in these bubbles. We propose numerical tools to detect the liquid-vapor equilibrium. The critical curves are reached consistently regardless of the thermodynamic path we chose to obtain the low densities. We analyze the equilibrium between the gas of the bubbles and the liquid. At high temperature, we identify the supercritical region characterized by one homogeneous fluid, rich in ionic species. We show that the chemical speciation is very different from the one obtained at ambient pressure conditions. Critical curves are necessary to understand the separation and degassing of volatiles during the recovery from a giant impact. Acknowledgements: This research was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement n°681818 - IMPACT). The ab initio simulations were performed on the GENCI supercomputers, under eDARI/CINES grants x106368.

Property measurements and solidification studies by electrostatic levitation.

PubMed

Paradis, Paul-François; Yu, Jianding; Ishikawa, Takehiko; Yoda, Shinichi

2004-11-01

The National Space Development Agency of Japan has recently developed several electrostatic levitation furnaces and implemented new techniques and procedures for property measurement, solidification studies, and atomic structure research. In addition to the contamination-free environment for undercooled and liquid metals and semiconductors, the newly developed facilities possess the unique capabilities of handling ceramics and high vapor pressure materials, reducing processing time, and imaging high luminosity samples. These are exemplified in this paper with the successful processing of BaTiO(3). This allowed measurement of the density of high temperature solid, liquid, and undercooled phases. Furthermore, the material resulting from containerless solidification consisted of micrometer-size particles and a glass-like phase exhibiting a giant dielectric constant exceeding 100,000.

Giant aneurysms: A gender-specific complication of Kawasaki disease?

PubMed

Dietz, Sanne M; Kuipers, Irene M; Tacke, Carline E A; Koole, Jeffrey C D; Hutten, Barbara A; Kuijpers, Taco W

2017-10-01

Kawasaki disease (KD) is a pediatric vasculitis of unknown origin. Its main complication is the development of coronary artery aneurysms (CAA) with giant CAA at the end of the spectrum. In this cohort study, we evaluated the association between patient characteristics and the development of giant CAA based on z-scores. Multivariable, multinomial logistic regression analysis was used to identify variables associated with giant CAA. A total of 301 KD patients, comprising 216 patients without enlargement, 45 with small-sized, 19 with medium-sized, and 21 with giant CAA with all echocardiographies at our center were retrospectively included. Remarkably, 95% of patients with giant CAA were boys. In addition to 'no/late intravenous immunoglobulin (IVIG) treatment', 'male gender' (OR 16.23, 95% CI 1.88-140.13), 'age<1 year' (OR 7.49, 95% CI 2.29-24.46), and 'IVIG re-treatment (9.79, 95% CI 2.79-34.37)' were significantly associated with an increased risk of giant CAA, with patients without enlargement as reference. Compared to patients with medium-sized CAA, 'IVIG re-treatment' was significantly associated with giant CAA. The majority of giant CAA continued to increase in size during the first 40 days. We identified risk factors associated with an increased risk of giant CAA. The difference in variables between the giant CAA group and the other CAA subgroups suggests a separation between patients with the treatment-resistant giant CAA and the other IVIG-responsive patients, in which gender may be factored as a most relevant genetic trait. The increase in size during the first 2 months indicates the need for repeated echocardiography. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Late-type giants with infrared excess. I. Lithium abundances

NASA Astrophysics Data System (ADS)

Jasniewicz, G.; Parthasarathy, M.; de Laverny, P.; Thévenin, F.

1999-02-01

de la Reza et al. (1997) suggested that all K giants become Li-rich for a short time. During this period the giants are associated with an expanding thin circumstellar shell supposedly triggered by an abrupt internal mixing mechanism resulting in the surface Li enrichment. In order to test this hypothesis twenty nine late-type giants with far-infrared excess from the list of Zuckerman et al. (1995) were observed in the Li-region to study the connection between the circumstellar shells and Li abundance. Eight giants have been found to have log epsilon (Li) > 1.0. In the remaining giants the Li abundance is found to be much lower. HD 219025 is found to be a rapidly rotating (projected rotational velocity of 23 +/-3 km s(-1) ), dusty and Li-rich (log epsilon (Li) = 3.0+/-0.2) K giant. Absolute magnitude derived from the Hipparcos parallax reveals that it is a giant and not a pre-main-sequence star. The evolutionary status of HD 219025 seems to be similar to that of HDE 233517 which is also a rapidly rotating, dusty and Li-rich K giant. The Hipparcos parallaxes of all the well studied Li-rich K giants show that most of them are brighter than the ``clump" giants. Their position in the H-R diagram indicates that they have gone through mixing and the initial abundance of Li is not preserved. There seems to be no correlations between Li abundances, rotational velocities and carbon isotope ratios. The only satisfactory explanation for the overabundance of lithium in these giants is the creation of Li by the extra deep mixing and the associated ``cool bottom processing". Based on observations obtained at the European Southern Observatory, La Silla, Chile, and at the Observatoire de Haute Provence, France.

Identifying Li-rich giants from low-resolution spectroscopic survey

NASA Astrophysics Data System (ADS)

Kumar, Yerra Bharat; Reddy, Bacham Eswar; Zhao, Gang

2018-04-01

In this paper we discuss our choice of a large unbiased sample used for the survey of red giant branch stars for finding Li-rich K giants, and the method used for identifying Li-rich candidates using low-resolution spectra. The sample has 2000 giants within a mass range of 0.8 to 3.0it{M}_{⊙}. Sample stars were selected from the Hipparcos catalogue with colour (B-V) and luminosity (it{L}/it{L}_{⊙}) in such way that the sample covers RGB evolution from its base towards RGB tip passing through first dredge-up and luminosity bump. Low-resolution (R ≈ 2000, 3500, 5000) spectra were obtained for all sample stars. Using core strength ratios of lines at Li I 6707 Å and its adjacent line Ca I 6717 Å we successfully identified 15 K giants with A(Li) > 1.5 dex, which are defined as Li-rich K giants. The results demonstrate the usefulness of low-resolution spectra to measure Li abundance and identify Li-rich giants from a large sample of stars in relatively shorter time periods.

The Longevity of Water Ice on Ganymedes and Europas around Migrated Giant Planets

NASA Astrophysics Data System (ADS)

Lehmer, Owen R.; Catling, David C.; Zahnle, Kevin J.

2017-04-01

The gas giant planets in the Solar System have a retinue of icy moons, and we expect giant exoplanets to have similar satellite systems. If a Jupiter-like planet were to migrate toward its parent star the icy moons orbiting it would evaporate, creating atmospheres and possible habitable surface oceans. Here, we examine how long the surface ice and possible oceans would last before being hydrodynamically lost to space. The hydrodynamic loss rate from the moons is determined, in large part, by the stellar flux available for absorption, which increases as the giant planet and icy moons migrate closer to the star. At some planet-star distance the stellar flux incident on the icy moons becomes so great that they enter a runaway greenhouse state. This runaway greenhouse state rapidly transfers all available surface water to the atmosphere as vapor, where it is easily lost from the small moons. However, for icy moons of Ganymede’s size around a Sun-like star we found that surface water (either ice or liquid) can persist indefinitely outside the runaway greenhouse orbital distance. In contrast, the surface water on smaller moons of Europa’s size will only persist on timescales greater than 1 Gyr at distances ranging 1.49-0.74 au around a Sun-like star for Bond albedos of 0.2 and 0.8, where the lower albedo becomes relevant if ice melts. Consequently, small moons can lose their icy shells, which would create a torus of H atoms around their host planet that might be detectable in future observations.

The Longevity of Water Ice on Ganymedes and Europas around Migrated Giant Planets

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

Lehmer, Owen R.; Catling, David C.; Zahnle, Kevin J., E-mail: olehmer@gmail.com

The gas giant planets in the Solar System have a retinue of icy moons, and we expect giant exoplanets to have similar satellite systems. If a Jupiter-like planet were to migrate toward its parent star the icy moons orbiting it would evaporate, creating atmospheres and possible habitable surface oceans. Here, we examine how long the surface ice and possible oceans would last before being hydrodynamically lost to space. The hydrodynamic loss rate from the moons is determined, in large part, by the stellar flux available for absorption, which increases as the giant planet and icy moons migrate closer to themore » star. At some planet–star distance the stellar flux incident on the icy moons becomes so great that they enter a runaway greenhouse state. This runaway greenhouse state rapidly transfers all available surface water to the atmosphere as vapor, where it is easily lost from the small moons. However, for icy moons of Ganymede’s size around a Sun-like star we found that surface water (either ice or liquid) can persist indefinitely outside the runaway greenhouse orbital distance. In contrast, the surface water on smaller moons of Europa’s size will only persist on timescales greater than 1 Gyr at distances ranging 1.49–0.74 au around a Sun-like star for Bond albedos of 0.2 and 0.8, where the lower albedo becomes relevant if ice melts. Consequently, small moons can lose their icy shells, which would create a torus of H atoms around their host planet that might be detectable in future observations.« less

Milliscale Self-Integration of Megamolecule Biopolymers on a Drying Gas-Aqueous Liquid Crystalline Interface.

PubMed

Okeyoshi, Kosuke; Okajima, Maiko K; Kaneko, Tatsuo

2016-06-13

A drying environment is always a proposition faced by dynamic living organisms using water, which are driven by biopolymer-based micro- and macrostructures. Here, we introduce a drying process for aqueous liquid crystalline (LC) solutions composed of biopolymer with extremely high molecular weight components such as polysaccharides, cytoskeletal proteins, and DNA. On controlling the mobility of the LC microdomain, the solutions showed milliscale self-integration starting from the unstable gas-LC interface during drying. In particular, we first identified giant rod-like microdomains (∼1 μm diameter and more than 20 μm length) of the mega-molecular polysaccharide, sacran, which is remarkably larger than other polysaccharides. These microdomains led to the formation of a single milliscale macrodomain on the interface. In addition, the dried polymer films on a solid substrate also revealed that such integration depends on the size of the microdomain. We envision that this simple drying method will be useful not only for understanding the biopolymer hierarchization at the macroscale level but also for preparation of surfaces with direction controllability, as seen in living organisms, for use in various fields such as diffusion, mechanics, and photonics.

A preliminary investigation of the variables affecting the distribution of giant gartersnakes (Thamnophis gigas) in the Sacramento Valley, California

USGS Publications Warehouse

Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

2015-09-30

Giant gartersnakes (Thamnophis gigas) comprise a species of rare, semi-aquatic snake precinctive to the Central Valley of California. Because of the loss of more than 90% of their natural habitat, giant gartersnakes are listed as Threatened by the United States and California endangered species acts. Little is known, however, about the distribution of giant gartersnakes in the Sacramento Valley, which is where most extant populations occur. We conducted detection-nondetection surveys for giant gartersnakes throughout the rice-growing regions of the Sacramento Valley, and used occupancy models to examine evidence for the effects of landscape-scale GIS-derived variables, local habitat and vegetation composition, and prey communities on patterns of giant gartersnake occurrence. Although our results are based on a relatively small sample of sites, we found that distance to historic marsh, relative fish count, and an interaction of distance to historic marsh with proportion of habitat composed of submerged vegetation were important variables for explaining occupancy of giant gartersnakes. In particular, giant gartersnakes were more likely to occur closer to historic marsh and where relatively fewer fish were captured in traps. At locations in or near historic marsh, giant gartersnakes were more likely to occur in areas with less submerged vegetation, but this relationship was reversed (and more uncertain) at sites distant from historic marsh. Additional research with a larger sample of sites would further elucidate the distribution of giant gartersnakes in the Sacramento Valley.

Synergistic Growth of Giant Wormlike Micelles in Ternary Mixed Surfactant Solutions: Effect of Octanoic Acid.

PubMed

Georgieva, Gergana S; Anachkov, Svetoslav E; Lieberwirth, Ingo; Koynov, Kaloian; Kralchevsky, Peter A

2016-12-06

The synergistic growth of giant wormlike micelles in ternary mixed solutions composed of an anionic surfactant (sodium laurylethersulfate, SLES), a zwitterionic surfactant (cocamidopropyl betaine, CAPB), and octanoic acid (HC8) is studied. Rheological data and their analysis in terms of Cole-Cole plots and micellar characteristic times are presented, and the micellar structures behind the observed rheological behavior are revealed by cryo-TEM micrographs. The surfactant composition is fixed near the maximal micelle size of the binary SLES + CAPB system, whereas the concentration of HC8 is varied. At a given HC8 concentration, the viscosity of the ternary micellar solutions exhibits a very high and sharp peak. Polarized-light optical microscopy indicates that all investigated solutions are isotropic rather than liquid-crystalline. The cryo-TEM imaging shows complex phase behavior: wormlike micelles to the left of the peak, giant entangled wormlike micelles at the peak, and long wormlike micelles coexisting with multiconnected micellar aggregates to the right of the peak. The formation of multiconnected micelles leads to a drop in viscosity at the higher concentrations. The results contribute to a better understanding of the structure-rheology relations in micellar surfactant solutions and could be useful for controlling the properties of formulations in personal-care and house-hold detergency.

Surface alloy engineering in 2D trigonal lattice: giant Rashba spin splitting and two large topological gaps

NASA Astrophysics Data System (ADS)

Liu, Zhao; Jin, Yingdi; Yang, Yuchen; Wang, Z. F.; Yang, Jinlong

2018-02-01

We demonstrate that sp 2 based trigonal lattice can exhibit giant Rashba splitting and two large topological gaps simultaneously. First, an effective tight binding model is developed to describe the Rashba spin-orbit coupling (SOC) on a real surface and give a topological phase diagram based on two independent SOC parameters. Second, based on density functional theory calculations, it is proposed that Au/Si(111)-\\sqrt{3}× \\sqrt{3} surface with 1/3 monolayer Bi coverage is a good material candidate to realize both giant Rashba splitting and two large topological gaps. These results would inspire great research interests for searching two-dimensional topological insulator and manipulating Rashba spin splitting through surface alloy engineering.

Water and Volatiles in the Outer Solar System

NASA Astrophysics Data System (ADS)

Grasset, O.; Castillo-Rogez, J.; Guillot, T.; Fletcher, L. N.; Tosi, F.

2017-10-01

Space exploration and ground-based observations have provided outstanding evidence of the diversity and the complexity of the outer solar system. This work presents our current understanding of the nature and distribution of water and water-rich materials from the water snow line to the Kuiper Belt. This synthesis is timely, since a thorough exploration of at least one object in each region of the outer solar system has now been achieved. Next steps, starting with the Juno mission now in orbit around Jupiter, will be more focused on understanding the processes at work than on describing the general characteristics of each giant planet systems. This review is organized in three parts. First, the nature and the distribution of water and volatiles in giant and intermediary planets are described from their inner core to their outer envelopes. A special focus is given to Jupiter and Saturn, which are much better understood than the two ice giants (Uranus and Neptune) thanks to the Galileo and Cassini missions. Second, the icy moons will be discussed. Space missions and ground-based observations have revealed the variety of icy surfaces in the outer system. While Europa, Enceladus, and maybe Titan present past or even active tectonic and volcanic activities, many other moons have been dead worlds for more than 3 billion years. Ice compositions found at these bodies are also complex and it is now commonly admitted that icy surfaces are never composed of pure ices. A detailed review of the distribution of non-ice materials on the surfaces and in the tenuous atmospheres of the moons is proposed, followed by a more focused discussion on the nature and the characteristics of the liquid layers trapped below the cold icy crusts that have been suggested in the icy Galilean moons, and in Enceladus, Dione, and Titan at Saturn. Finally, the recent observations collected by Dawn at Ceres and New Horizons at Pluto, as well as the state of knowledge of other transneptunian objects, are summarized, and complete this overview of the nature and distribution of ice-rich material in the outer solar system.

Interferon-gamma of the giant panda (Ailuropoda melanoleuca): complementary DNA cloning, expression, and phylogenetic analysis.

PubMed

Tao, Yaqiong; Zeng, Bo; Xu, Liu; Yue, Bisong; Yang, Dong; Zou, Fangdong

2010-01-01

Interferon-gamma (IFN-gamma) is the only member of type II IFN and is vital in the regulation of immune and inflammatory responses. Herein we report the cloning, expression, and sequence analysis of IFN-gamma from the giant panda (Ailuropoda melanoleuca). The open reading frame of this gene is 501 base pair in length and encodes a polypeptide consisting of 166 amino acids. All conserved N-linked glycosylation sites and cysteine residues among carnivores were found in the predicted amino acid sequence of the giant panda. Recombinant giant panda IFN-gamma with a V5 epitope and polyhistidine tag was expressed in HEK293 host cells and confirmed by Western blotting. Phylogenetic analysis of mammalian IFN-gamma-coding sequences indicated that the giant panda IFN-gamma was closest to that of carnivores, then to ungulates and dolphin, and shared a distant relationship with mouse and human. These results represent a first step into the study of IFN-gamma in giant panda.

Comparing the plant diversity between artificial forest and nature growth forest in a giant panda habitat.

PubMed

Kang, Dongwei; Wang, Xiaorong; Li, Shuang; Li, Junqing

2017-06-15

Artificial restoration is an important way to restore forests, but little is known about its effect on the habitat restoration of the giant panda. In the present study, we investigated the characteristics of artificial forest in the Wanglang Nature Reserve to determine whether through succession it has formed a suitable habitat for the giant panda. We compared artificial forest characteristics with those of natural habitat used by the giant panda. We found that the dominant tree species in artificial forest differed from those in the natural habitat. The artificial forest had lower plant species richness and diversity in the tree and shrub layers than did the latter, and its community structure was characterized by smaller tree and bamboo sizes, and fewer and lower bamboo clumps, but more trees and larger shrub sizes. The typical community collocation of artificial forest was a "Picea asperata + no-bamboo" model, which differs starkly from the giant panda's natural habitat. After several years of restoration, the artificial forest has failed to become a suitable habitat for the giant panda. Therefore, a simple way of planting individual trees cannot restore giant panda habitat; instead, habitat restoration should be based on the habitat requirements of the giant panda.

Giant Cornu Cutaneum Superimposed on Basal Cell Carcinoma.

PubMed

Agirgol, S; Mansur, A T; Bozkurt, K; Azakli, H N; Babacan, A; Dikmen, A

2015-09-01

Cornu cutaneum (CC) is a clinical term that describes the horn-like keratotic lesions extending vertically from the skin. Benign, premalignant or malignant lesions may be present at the base of CC. Seborrhoeic keratosis and squamous cell carcinoma (SCC) are the most commonly reported benign and malignant forms, respectively. Basal cell carcinoma (BCC) at the base is rare. Here, we report on an 85-year old female patient having multiple CC lesions, one being giant on her face and two of the lesions diagnosed with BCC at the base. This case is of significance due to the presence of giant and multiple CC and detection of BCC at the base of more than one lesion. This present case indicates the need for the treatment of possible malignant lesions underlying CC in the elderly by total surgical excision.

Microplate-Based Evaluation of the Sugar Yield from Giant Reed, Giant Miscanthus and Switchgrass after Mild Chemical Pre-Treatments and Hydrolysis with Tailored Trichoderma Enzymatic Blends.

PubMed

Cianchetta, Stefano; Bregoli, Luca; Galletti, Stefania

2017-11-01

Giant reed, miscanthus, and switchgrass are considered prominent lignocellulosic feedstocks to obtain fermentable sugars for biofuel production. The bioconversion into sugars requires a delignifying pre-treatment step followed by hydrolysis with cellulase and other accessory enzymes like xylanase, especially in the case of alkali pre-treatments, which retain the hemicellulose fraction. Blends richer in accessory enzymes than commercial mix can be obtained growing fungi on feedstock-based substrates, thus ten selected Trichoderma isolates, including the hypercellulolytic strain Trichoderma reesei Rut-C30, were grown on giant reed, miscanthus, or switchgrass-based substrates. The produced enzymes were used to saccharify the corresponding feedstocks, compared to a commercial enzymatic mix (6 FPU/g). Feedstocks were acid (H 2 SO 4 0.2-2%, w/v) or alkali (NaOH 0.02-0.2%, w/v) pre-treated. A microplate-based approach was chosen for most of the experimental steps due to the large number of samples. The highest bioconversion was generally obtained with Trichoderma harzianum Or4/99 enzymes (78, 89, and 94% final sugar yields at 48 h for giant reed, miscanthus, and switchgrass, respectively), with significant increases compared to the commercial mix, especially with alkaline pre-treatments. The differences in bioconversion yields were only partially caused by xylanases (maximum R 2  = 0.5), indicating a role for other accessory enzymes.

Crystal engineering of giant molecules based on perylene diimide conjugated polyhedral oligomeric silsesquioxane nano-atom

NASA Astrophysics Data System (ADS)

Ren, He

Molecular architectures and topologies are found contributing to the formation of supramolecular structures of giant molecules. Dr. Cheng's research group developed a diverse of giant molecules via precisely controlled chemistry synthetic routes. These giant molecules can be categorized into several different families, namely giant surfactants, giant shape amphiphiles and giant polyhedron. By analyzing the hierarchical structures of these carefully designed and precisely synthesized giant molecules, the structural factors which affect, or even dominates, in some cases, the formation of supramolecular structures are revealed in these intensive researches. The results will further contribute to the understanding of dependence of supramolecular structures on molecular designs as well as molecular topology, and providing a practical solution to the scaling up of microscopic molecular functionalities to macroscopic material properties. Molecular Nano Particles (MNPs), including fullerene (C60), POSS, Polyoxometalate (POM) and proteins etc., is defined and applied as a specific type of building blocks in the design and synthesis of giant molecules. The persistence in shape and symmetry is considered as one of the major properties of MNPs. This persistence will support the construction of giant molecules for further supramolecular structures' study by introducing specific shapes, or precisely located side groups which will facilitate self-assembling behaviors with pre-programmed secondary interactions. Dictating material physical properties by its chemical composition is an attractive yet currently failed approach in the study of materials. However, the pursuit of determining material properties by microscopic molecular level properties is never seized, and found its solution when the idea of crystal engineering is raised: should each atom in the material is located exactly where it is designed to be and is properly bonded, the property of the material is hence determined. In such "bottom-up" approach, the precise fabrication of 2 nm 100 nm nanostructures, is of great research interest. In this thesis, crystal engineering of giant molecules based on PDI conjugated POSS Nano-Atom (PDI-BPOSS) nano-atoms via self-assembly is performed and studied. Herein, three different giant molecules were synthesized: shape amphiphile, m-phenyl-(PDI-BPOSS)2 (S1) and tetrahedron, R-(PDI-BPOSS)4 (S2) and S-(PDI-BPOSS)4 (S3). Single crystals were grown for S1 and S2, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and transmission electron microscopy (TEM) were performed, and crystal structures of these samples were determined, while hexagonal superlattice without crystal order can be observed for S3 to exhibit crystal-like morphology.

On Lithium-rich Red Giants. I. Engulfment of Substellar Companions

NASA Astrophysics Data System (ADS)

Aguilera-Gómez, Claudia; Chanamé, Julio; Pinsonneault, Marc H.; Carlberg, Joleen K.

2016-10-01

A small fraction of red giants are known to be lithium (Li) rich, in contradiction with expectations from stellar evolutionary theory. A possible explanation for these atypical giants is the engulfment of an Li-rich planet or brown dwarf by the star. In this work, we model the evolution of Li abundance in canonical red giants including the accretion of a substellar mass companion. We consider a wide range of stellar and companion masses, Li abundances, stellar metallicities, and planetary orbital periods. Based on our calculations, companions with masses lower than 15 {M}J dissolve in the convective envelope and can induce Li enrichment in regimes where extra mixing does not operate. Our models indicate that the accretion of a substellar companion can explain abundances up to A(Li) ≈ 2.2, setting an upper limit for Li-rich giants formed by this mechanism. Giants with higher abundances need another mechanism to be explained. For reasonable planetary distributions, we predict the Li abundance distribution of low-mass giants undergoing planet engulfment, finding that between 1% and 3% of them should have {{A}}({Li})≥slant 1.5. We show that depending on the stellar mass range, this traditional definition of Li-rich giants is misleading, as isolated massive stars would be considered anomalous while giants engulfing a companion would be set aside, flagged as normal. We explore the detectability of companion engulfment, finding that planets with masses higher than ∼ 7 {M}J produce a distinct signature, and that descendants of stars originating in the Li dip and low-luminosity red giants are ideal tests of this channel.

Giant electroresistance of super-tetragonal BiFeO3-based ferroelectric tunnel junctions.

PubMed

Yamada, Hiroyuki; Garcia, Vincent; Fusil, Stéphane; Boyn, Sören; Marinova, Maya; Gloter, Alexandre; Xavier, Stéphane; Grollier, Julie; Jacquet, Eric; Carrétéro, Cécile; Deranlot, Cyrile; Bibes, Manuel; Barthélémy, Agnès

2013-06-25

Ferroelectric tunnel junctions enable a nondestructive readout of the ferroelectric state via a change of resistance induced by switching the ferroelectric polarization. We fabricated submicrometer solid-state ferroelectric tunnel junctions based on a recently discovered polymorph of BiFeO3 with giant axial ratio ("T-phase"). Applying voltage pulses to the junctions leads to the highest resistance changes (OFF/ON ratio >10,000) ever reported with ferroelectric tunnel junctions. Along with the good retention properties, this giant effect reinforces the interest in nonvolatile memories based on ferroelectric tunnel junctions. We also show that the changes in resistance scale with the nucleation and growth of ferroelectric domains in the ultrathin BiFeO3 (imaged by piezoresponse force microscopy), thereby suggesting potential as multilevel memory cells and memristors.

Serosurvey of ex situ giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens) in China with implications for species conservation.

PubMed

Loeffler, I Kati; Howard, JoGayle; Montali, Richard J; Hayek, Lee-Ann; Dubovi, Edward; Zhang, Zhihe; Yan, Qigui; Guo, Wanzhu; Wildt, David E

2007-12-01

Conservation strategies for the giant panda (Ailuropoda melanoleuca) include the development of a self-sustaining ex situ population. This study examined the potential significance of infectious pathogens in giant pandas ex situ. Serologic antibody titers against canine distemper virus (CDV), canine parvovirus (CPV), canine adenovirus (CAV), canine coronavirus (CCV), canine herpesvirus, canine parainfluenza virus (CPIV), Toxoplasma gondii, Neospora caninum, and Leptospira interrogans were measured in 44 samples taken from 19 giant pandas between 1998 and 2003 at the Chengdu Research Base of Giant Panda Breeding in Sichuan, China. Seroassays also included samples obtained in 2003 from eight red pandas (Ailurus fulgens) housed at the same institution. All individuals had been vaccinated with a Chinese canine vaccine that included modified live CDV, CPV, CAV, CCV, and CPIV. Positive antibody titers were found only against CDV, CPV, and T. gondii. Sera were negative for antibodies against the other six pathogens. Results indicate that the quality of the vaccine may not be reliable and that it should not be considered protective or safe in giant pandas and red pandas. Positive antibody titers against T. gondii were found in seven of the 19 giant pandas. The clinical, subclinical, or epidemiologic significance of infection with these pathogens via natural exposure or from modified live vaccines in giant pandas is unknown. Research in this area is imperative to sustaining a viable population of giant pandas and other endangered species.

On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness

PubMed Central

Witton, Mark P.; Habib, Michael B.

2010-01-01

The size and flight mechanics of giant pterosaurs have received considerable research interest for the last century but are confused by conflicting interpretations of pterosaur biology and flight capabilities. Avian biomechanical parameters have often been applied to pterosaurs in such research but, due to considerable differences in avian and pterosaur anatomy, have lead to systematic errors interpreting pterosaur flight mechanics. Such assumptions have lead to assertions that giant pterosaurs were extremely lightweight to facilitate flight or, if more realistic masses are assumed, were flightless. Reappraisal of the proportions, scaling and morphology of giant pterosaur fossils suggests that bird and pterosaur wing structure, gross anatomy and launch kinematics are too different to be considered mechanically interchangeable. Conclusions assuming such interchangeability—including those indicating that giant pterosaurs were flightless—are found to be based on inaccurate and poorly supported assumptions of structural scaling and launch kinematics. Pterosaur bone strength and flap-gliding performance demonstrate that giant pterosaur anatomy was capable of generating sufficient lift and thrust for powered flight as well as resisting flight loading stresses. The retention of flight characteristics across giant pterosaur skeletons and their considerable robustness compared to similarly-massed terrestrial animals suggest that giant pterosaurs were not flightless. Moreover, the term ‘giant pterosaur’ includes at least two radically different forms with very distinct palaeoecological signatures and, accordingly, all but the most basic sweeping conclusions about giant pterosaur flight should be treated with caution. Reappraisal of giant pterosaur material also reveals that the size of the largest pterosaurs, previously suggested to have wingspans up to 13 m and masses up to 544 kg, have been overestimated. Scaling of fragmentary giant pterosaur remains have been misled by distorted fossils or used inappropriate scaling techniques, indicating that 10–11 m wingspans and masses of 200–250 kg are the most reliable upper estimates of known pterosaur size. PMID:21085624

Syncytial giant-cell hepatitis due to autoimmune hepatitis type II (LKM1+) presenting as subfulminant hepatitis.

PubMed

Ben-Ari, Z; Broida, E; Monselise, Y; Kazatsker, A; Baruch, J; Pappo, O; Skappa, E; Tur-Kaspa, R

2000-03-01

Giant cell hepatitis (GCH) in adults is a rare event. The diagnosis of GCH is based on findings of syncytial giant hepatocytes. It is commonly associated with either viral infection or autoimmune hepatitis type I. A patient with GCH due to autoimmune hepatitis type II (LKM1+) is described, a combination that has not been previously reported. Corticosteroid therapy was effective in decreasing serum liver enzymes; however, the patient deteriorated rapidly and developed subfulminant hepatic failure. Although an emergency orthotopic liver transplantation was performed, the patient died because of reperfusion injury. Interestingly, only a few giant hepatocytes were noted in the explanted liver. This case stresses the association of GCH with autoimmune disorders, the possible immune mechanism involved in the formation of giant cell hepatocytes, and illustrates the rapidly progressive course and unfavorable prognosis that these patients can develop.

Theories of Giant Planet Formation

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

1998-01-01

An overview of current theories of planetary formation, with emphasis on giant planets, is presented. The most detailed models are based upon observations of our own Solar System and of young stars and their environments. While these models predict that rocky planets should form around most single stars, the frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Most models for extrasolar giant planets suggest that they formed as did Jupiter and Saturn (in nearly circular orbits, far enough from the star that ice could), and subsequently migrated to their current positions, although some models suggest in situ formation.

Oscillating red giants in eclipsing binary systems: empirical reference value for asteroseismic scaling relation

NASA Astrophysics Data System (ADS)

Themeßl, N.; Hekker, S.; Southworth, J.; Beck, P. G.; Pavlovski, K.; Tkachenko, A.; Angelou, G. C.; Ball, W. H.; Barban, C.; Corsaro, E.; Elsworth, Y.; Handberg, R.; Kallinger, T.

2018-05-01

The internal structures and properties of oscillating red-giant stars can be accurately inferred through their global oscillation modes (asteroseismology). Based on 1460 days of Kepler observations we perform a thorough asteroseismic study to probe the stellar parameters and evolutionary stages of three red giants in eclipsing binary systems. We present the first detailed analysis of individual oscillation modes of the red-giant components of KIC 8410637, KIC 5640750 and KIC 9540226. We obtain estimates of their asteroseismic masses, radii, mean densities and logarithmic surface gravities by using the asteroseismic scaling relations as well as grid-based modelling. As these red giants are in double-lined eclipsing binaries, it is possible to derive their independent dynamical masses and radii from the orbital solution and compare it with the seismically inferred values. For KIC 5640750 we compute the first spectroscopic orbit based on both components of this system. We use high-resolution spectroscopic data and light curves of the three systems to determine up-to-date values of the dynamical stellar parameters. With our comprehensive set of stellar parameters we explore consistencies between binary analysis and asteroseismic methods, and test the reliability of the well-known scaling relations. For the three red giants under study, we find agreement between dynamical and asteroseismic stellar parameters in cases where the asteroseismic methods account for metallicity, temperature and mass dependence as well as surface effects. We are able to attain agreement from the scaling laws in all three systems if we use Δνref, emp = 130.8 ± 0.9 μHz instead of the usual solar reference value.

Territoriality of Giant Otter Groups in an Area with Seasonal Flooding

PubMed Central

Leuchtenberger, Caroline; Magnusson, William E.; Mourão, Guilherme

2015-01-01

Territoriality carries costs and benefits, which are commonly affected by the spatial and temporal abundance and predictability of food, and by intruder pressure. Giant otters (Pteronura brasiliensis) live in groups that defend territories along river channels during the dry season using chemical signals, loud vocalizations and agonistic encounters. However, little is known about the territoriality of giant otters during the rainy season, when groups leave their dry season territories and follow fish dispersing into flooded areas. The objective of this study was to analyze long-term territoriality of giant otter groups in a seasonal environment. The linear extensions of the territories of 10 giant otter groups were determined based on locations of active dens, latrines and scent marks in each season. Some groups overlapped the limits of neighboring territories. The total territory extent of giant otters was correlated with group size in both seasons. The extent of exclusive territories of giant otter groups was negatively related to the number of adults present in adjacent groups. Territory fidelity ranged from 0 to 100% between seasons. Some groups maintained their territory for long periods, which demanded constant effort in marking and re-establishing their territories during the wet season. These results indicate that the defense capacity of groups had an important role in the maintenance of giant otter territories across seasons, which may also affect the reproductive success of alpha pairs. PMID:25955248

Pseudogenization of the umami taste receptor gene Tas1r1 in the giant panda coincided with its dietary switch to bamboo.

PubMed

Zhao, Huabin; Yang, Jian-Rong; Xu, Huailiang; Zhang, Jianzhi

2010-12-01

Although it belongs to the order Carnivora, the giant panda is a vegetarian with 99% of its diet being bamboo. The draft genome sequence of the giant panda shows that its umami taste receptor gene Tas1r1 is a pseudogene, prompting the proposal that the loss of the umami perception explains why the giant panda is herbivorous. To test this hypothesis, we sequenced all six exons of Tas1r1 in another individual of the giant panda and five other carnivores. We found that the open reading frame (ORF) of Tas1r1 is intact in all these carnivores except the giant panda. The rate ratio (ω) of nonsynonymous to synonymous substitutions in Tas1r1 is significantly higher for the giant panda lineage than for other carnivore lineages. Based on the ω change and the observed number of ORF-disrupting substitutions, we estimated that the functional constraint on the giant panda Tas1r1 was relaxed ∼ 4.2 Ma, with its 95% confidence interval between 1.3 and 10 Ma. Our estimate matches the approximate date of the giant panda's dietary switch inferred from fossil records. It is probable that the giant panda's decreased reliance on meat resulted in the dispensability of the umami taste, leading to Tas1r1 pseudogenization, which in turn reinforced its herbivorous life style because of the diminished attraction of returning to meat eating in the absence of Tas1r1. Nonetheless, additional factors are likely involved because herbivores such as cow and horse still retain an intact Tas1r1.

Pseudogenization of the Umami Taste Receptor Gene Tas1r1 in the Giant Panda Coincided with its Dietary Switch to Bamboo

PubMed Central

Zhao, Huabin; Yang, Jian-Rong; Xu, Huailiang; Zhang, Jianzhi

2010-01-01

Although it belongs to the order Carnivora, the giant panda is a vegetarian with 99% of its diet being bamboo. The draft genome sequence of the giant panda shows that its umami taste receptor gene Tas1r1 is a pseudogene, prompting the proposal that the loss of the umami perception explains why the giant panda is herbivorous. To test this hypothesis, we sequenced all six exons of Tas1r1 in another individual of the giant panda and five other carnivores. We found that the open reading frame (ORF) of Tas1r1 is intact in all these carnivores except the giant panda. The rate ratio (ω) of nonsynonymous to synonymous substitutions in Tas1r1 is significantly higher for the giant panda lineage than for other carnivore lineages. Based on the ω change and the observed number of ORF-disrupting substitutions, we estimated that the functional constraint on the giant panda Tas1r1 was relaxed ∼4.2 Ma, with its 95% confidence interval between 1.3 and 10 Ma. Our estimate matches the approximate date of the giant panda's dietary switch inferred from fossil records. It is probable that the giant panda's decreased reliance on meat resulted in the dispensability of the umami taste, leading to Tas1r1 pseudogenization, which in turn reinforced its herbivorous life style because of the diminished attraction of returning to meat eating in the absence of Tas1r1. Nonetheless, additional factors are likely involved because herbivores such as cow and horse still retain an intact Tas1r1. PMID:20573776

Quantifying landscape linkages among giant panda subpopulations in regional scale conservation.

PubMed

Qi, Dunwu; Hu, Yibo; Gu, Xiaodong; Yang, Xuyi; Yang, Guang; Wei, Fuwen

2012-06-01

Understanding habitat requirements and identifying landscape linkages are essential for the survival of isolated populations of endangered species. Currently, some of the giant panda populations are isolated, which threatens their long-term survival, particularly in the Xiaoxiangling mountains. In the present study, we quantified niche requirements and then identified potential linkages of giant panda subpopulations in the most isolated region, using ecological niche factor analysis and a least-cost path model. Giant pandas preferred habitat with conifer forest and gentle slopes (>20 to ≤30°). Based on spatial distribution of suitable habitat, linkages were identified for the Yele subpopulation to 4 other subpopulations (Liziping, Matou, Xinmin and Wanba). Their lengths ranged from 15 to 54 km. The accumulated cost ranged from 693 to 3166 and conifer forest covered over 31%. However, a variety of features (e.g. major roads, human settlements and large unforested areas) might act as barriers along the linkages for giant panda dispersal. Our analysis quantified giant panda subpopulation connectivity to ensure long-term survival. © 2012 ISZS, Blackwell Publishing and IOZ/CAS.

High quality, giant crystalline-Ge stripes on insulating substrate by rapid-thermal-annealing of Sn-doped amorphous-Ge in solid-liquid coexisting region

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

Matsumura, Ryo; JSPS Research Fellow, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083; Kai, Yuki

Formation of large-grain (≥30 μm) Ge crystals on insulating substrates is strongly desired to achieve high-speed thin-film transistors. For this purpose, we propose the methods of Sn-doping into amorphous-Ge combined with rapid-thermal-annealing (RTA) in the solid-liquid coexisting temperature region for the Ge-Sn alloy system. The densities of micro-crystal-nuclei formed in this temperature region become low by tuning the RTA temperature close to the liquidus curve, which enhances the lateral growth of GeSn. Thanks to the very small segregation coefficient of Sn, almost all Sn atoms segregate toward edges of the stripes during growth. Agglomeration of GeSn degrades the surface morphologies;more » however, it is significantly improved by lowering the initial Sn concentration. As a result, pure Ge with large crystal grains (∼40 μm) with smooth surface are obtained by optimizing the initial Sn concentration as low as 3 ∼ 5%. Lateral growth lengths are further increased through decreasing the number of nuclei in stripes by narrowing stripe width. In this way, high-crystallinity giant Ge crystals (∼200 μm) are obtained for the stripe width of 3 μm. This “Si-seed free” technique for formation of large-grain pure Ge crystals is very useful to realize high-performance thin-film devices on insulator.« less

Spectral calibration in the mid-infrared: Challenges and solutions

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

Sloan, G. C.; Herter, T. L.; Houck, J. R.

2015-01-01

We present spectra obtained with the Infrared Spectrograph on the Spitzer Space Telescope of 33 K giants and 20 A dwarfs to assess their suitability as spectrophotometric standard stars. The K giants confirm previous findings that the strength of the SiO absorption band at 8 μm increases for both later optical spectral classes and redder (B–V){sub 0} colors, but with considerable scatter. For K giants, the synthetic spectra underpredict the strengths of the molecular bands from SiO and OH. For these reasons, the assumed true spectra for K giants should be based on the assumption that molecular band strengths inmore » the infrared can be predicted accurately from neither optical spectral class or color nor synthetric spectra. The OH bands in K giants grow stronger with cooler stellar temperatures, and they are stronger than predicted by synthetic spectra. As a group, A dwarfs are better behaved and more predictable than the K giants, but they are more likely to show red excesses from debris disks. No suitable A dwarfs were located in parts of the sky continuously observable from Spitzer, and with previous means of estimating the true spectra of K giants ruled out, it was necessary to use models of A dwarfs to calibrate spectra of K giants from observed spectral ratios of the two groups and then use the calibrated K giants as standards for the full database of infrared spectra from Spitzer. We also describe a lingering artifact that affects the spectra of faint blue sources at 24 μm.« less

A hybrid scenario for gas giant planet formation in rings

NASA Astrophysics Data System (ADS)

Durisen, Richard H.; Cai, Kai; Mejía, Annie C.; Pickett, Megan K.

2005-02-01

The core-accretion mechanism for gas giant formation may be too slow to create all observed gas giant planets during reasonable gas disk lifetimes, but it has yet to be firmly established that the disk instability model can produce permanent bound gaseous protoplanets under realistic conditions. Based on our recent simulations of gravitational instabilities in disks around young stars, we suggest that, even if instabilities due to disk self-gravity do not produce gaseous protoplanets directly, they may create persistent dense rings that are conducive to accelerated growth of gas giants through core accretion. The rings occur at and near the boundary between stable and unstable regions of the disk and appear to be produced by resonances with discrete spiral modes on the unstable side.

Near infrared reflectance spectroscopy studies of Chinese giant salamanders in aquaculture production

USDA-ARS?s Scientific Manuscript database

NIR spectra were collected at three surface locations for Chinese giant salamanders to ascertain whether spectral signatures could be separated by anatomical, presumably physiologically-based, locations. The first location was the smooth area immediately above the cloaca on the animal’s abdomen, whi...

Spectral discrimination of giant reed (Arundo donax L.): A seasonal study in riparian areas

NASA Astrophysics Data System (ADS)

Fernandes, Maria Rosário; Aguiar, Francisca C.; Silva, João M. N.; Ferreira, Maria Teresa; Pereira, José M. C.

2013-06-01

The giant reed (Arundo donax L.) is amongst the one hundred worst invasive alien species of the world, and it is responsible for biodiversity loss and failure of ecosystem functions in riparian habitats. In this work, field spectroradiometry was used to assess the spectral separability of the giant reed from the adjacent vegetation and from the common reed, a native similar species. The study was conducted at different phenological periods and also for the giant reed stands regenerated after mechanical cutting (giant reed_RAC). A hierarchical procedure using Kruskal-Wallis test followed by Classification and Regression Trees (CART) was used to select the minimum number of optimal bands that discriminate the giant reed from the adjacent vegetation. A new approach was used to identify sets of wavelengths - wavezones - that maximize the spectral separability beyond the minimum number of optimal bands. Jeffries Matusita and Bhattacharya distance were used to evaluate the spectral separability using the minimum optimal bands and in three simulated satellite images, namely Landsat, IKONOS and SPOT. Giant reed was spectrally separable from the adjacent vegetation, both at the vegetative and the senescent period, exception made to the common reed at the vegetative period. The red edge region was repeatedly selected, although the visible region was also important to separate the giant reed from the herbaceous vegetation and the mid infrared region to the discrimination from the woody vegetation. The highest separability was obtained for the giant reed_RAC stands, due to its highly homogeneous, dense and dark-green stands. Results are discussed by relating the phenological, morphological and structural features of the giant reed stands and the adjacent vegetation with their optical traits. Weaknesses and strengths of the giant reed spectral discrimination are highlighted and implications of imagery selection for mapping purposes are argued based on present results.

Timescales of quartz crystallization and the longevity of the Bishop giant magma body.

PubMed

Gualda, Guilherme A R; Pamukcu, Ayla S; Ghiorso, Mark S; Anderson, Alfred T; Sutton, Stephen R; Rivers, Mark L

2012-01-01

Supereruptions violently transfer huge amounts (100 s-1000 s km(3)) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted ~760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain the timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500-3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies.

Timescales of Quartz Crystallization and the Longevity of the Bishop Giant Magma Body

PubMed Central

Gualda, Guilherme A. R.; Pamukcu, Ayla S.; Ghiorso, Mark S.; Anderson, Alfred T.; Sutton, Stephen R.; Rivers, Mark L.

2012-01-01

Supereruptions violently transfer huge amounts (100 s–1000 s km3) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted ∼760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain the timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500–3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies. PMID:22666359

Tunable Affinity and Molecular Architecture Lead to Diverse Self-Assembled Supramolecular Structures in Thin Films

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

Hsu, Chih-Hao; Dong, Xue-Hui; Lin, Zhiwei

2015-12-03

The self-assembly behaviors of specifically designed giant surfactants are systematically studied in thin films using grazing incident X-ray and transmission electron microscopy (TEM), focusing on the effects of head surface functionalities and molecular architectures on nanostructure formation. Two molecular nanoparticles (MNPs) with different affinities, i.e., hydrophilic carboxylic acid functionalized [60]fullerene (AC60) and omniphobic fluorinated polyhedral oligomeric silsesquioxane (FPOSS), are utilized as heads of the giant surfactants. By covalently tethering these functional MNPs onto the chain end or the junction point of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer, linear and star-like giant surfactants possess distinct molecular architectures are constructed. With fixed lengthmore » of the PEO block, the molecular weight change of the PS block originates the phase formation and transition. Due to the distinct affinity, the AC60-based giant surfactants form two-component morphologies, while three-component morphologies are found in the FPOSS-based ones. A PS block stretching parameter is introduced to characterize the PS chain conformation in different morphologies. The highly diverse self-assembly behaviors and the tunable dimensions in thin films suggest the giant surfactants could be a promising and robust platform for nanolithography applications.« less

Isoscalar giant resonances in Ca48

NASA Astrophysics Data System (ADS)

Lui, Y.-W.; Youngblood, D. H.; Shlomo, S.; Chen, X.; Tokimoto, Y.; Krishichayan; Anders, M.; Button, J.

2011-04-01

The giant resonance region from 9.5 MeV < Ex < 40 MeV in Ca48 has been studied with inelastic scattering of 240-MeV α particles at small angles, including 0°. 95-15+11% of E0 energy-weighted sum rule (EWSR), 83-16+10% of E2 EWSR, and 137 ± 20% of E1 EWSR were located below Ex=40 MeV. A comparison of the experimental data with calculated results for the isoscalar giant monopole resonance, obtained within the mean-field-based random-phase approximation, is also given.

Habitat assessment for giant pandas in the Qinling Mountain region of China

USGS Publications Warehouse

Feng, Tian-Tian; Van Manen, Frank T.; Zhao, Na-Xun; Li, Ming; Wei, Fu-Wen

2009-01-01

Because habitat loss and fragmentation threaten giant pandas (Ailuropoda melanoleuca), habitat protection and restoration are important conservation measures for this endangered species. However, distribution and value of potential habitat to giant pandas on a regional scale are not fully known. Therefore, we identified and ranked giant panda habitat in Foping Nature Reserve, Guanyinshan Nature Reserve, and adjacent areas in the Qinling Mountains of China. We used Mahalanobis distance and 11 digital habitat layers to develop a multivariate habitat signature associated with 247 surveyed giant panda locations, which we then applied to the study region. We identified approximately 128 km2 of giant panda habitat in Foping Nature Reserve (43.6% of the reserve) and 49 km2 in Guanyinshan Nature Reserve (33.6% of the reserve). We defined core habitat areas by incorporating a minimum patch-size criterion (5.5 km2) based on home-range size. Percentage of core habitat area was higher in Foping Nature Reserve (41.8% of the reserve) than Guanyinshan Nature Reserve (26.3% of the reserve). Within the larger analysis region, Foping Nature Reserve contained 32.7% of all core habitat areas we identified, indicating regional importance of the reserve. We observed a negative relationship between distribution of core areas and presence of roads and small villages. Protection of giant panda habitat at lower elevations and improvement of habitat linkages among core habitat areas are important in a regional approach to giant panda conservation.

Lunar and Planetary Science XXXV: Terrestrial Planets: Building Blocks and Differentiation

NASA Technical Reports Server (NTRS)

2004-01-01

The session "Terrestrial Planets: Building Blocks and Differentiation: included the following topics:Magnesium Isotopes in the Earth, Moon, Mars, and Pallasite Parent Body: High-Precision Analysis of Olivine by Laser-Ablation Multi-Collector ICPMS; Meteoritic Constraints on Collision Rates in the Primordial Asteroid Belt and Its Origin; New Constraints on the Origin of the Highly Siderophile Elements in the Earth's Upper Mantle; Further Lu-Hf and Sm-Nd Isotopic Data on Planetary Materials and Consequences for Planetary Differentiation; A Deep Lunar Magma Ocean Based on Neodymium, Strontium and Hafnium Isotope Mass Balance Partial Resetting on Hf-W System by Giant Impacts; On the Problem of Metal-Silicate Equilibration During Planet Formation: Significance for Hf-W Chronometry ; Solid Metal-Liquid Metal Partitioning of Pt, Re, and Os: The Effect of Carbon; Siderophile Element Abundances in Fe-S-Ni-O Melts Segregated from Partially Molten Ordinary Chondrite Under Dynamic Conditions; Activity Coefficients of Silicon in Iron-Nickel Alloys: Experimental Determination and Relevance for Planetary Differentiation; Reinvestigation of the Ni and Co Metal-Silicate Partitioning; Metal/Silicate Paritioning of P, Ga, and W at High Pressures and Temperatures: Dependence on Silicate Melt Composition; and Closure of the Fe-S-Si Liquid Miscibility Gap at High Pressure and Its Implications for Planetary Core Formation.

Isoscalar and isovector giant resonances in a self-consistent phonon coupling approach

NASA Astrophysics Data System (ADS)

Lyutorovich, N.; Tselyaev, V.; Speth, J.; Krewald, S.; Grümmer, F.; Reinhard, P.-G.

2015-10-01

We present fully self-consistent calculations of isoscalar giant monopole and quadrupole as well as isovector giant dipole resonances in heavy and light nuclei. The description is based on Skyrme energy-density functionals determining the static Hartree-Fock ground state and the excitation spectra within random-phase approximation (RPA) and RPA extended by including the quasiparticle-phonon coupling at the level of the time-blocking approximation (TBA). All matrix elements were derived consistently from the given energy-density functional and calculated without any approximation. As a new feature in these calculations, the single-particle continuum was included thus avoiding the artificial discretization usually implied in RPA and TBA. The step to include phonon coupling in TBA leads to small, but systematic, down shifts of the centroid energies of the giant resonances. These shifts are similar in size for all Skyrme parametrizations investigated here. After all, we demonstrate that one can find Skyrme parametrizations which deliver a good simultaneous reproduction of all three giant resonances within TBA.

Giant optical activity of sugar in thin soap films.

PubMed

Emile, Janine; Emile, Olivier; Ghoufi, Aziz; Moréac, Alain; Casanova, Federico; Ding, Minxia; Houizot, Patrick

2013-10-15

We report on enhanced experimental optical activity measurements of thin soap films in the presence of sugar. This unusual optical activity is linked to the intramolecular chiral conformation of the glucose molecules at the air/liquid interface. Choosing sodium dodecylsulfate (SDS) as a model surfactant and glucose as model sugar, favorable interactions between the anionic group -OSO3(-)- and the glucose molecules are highlighted. This induces an interfacial anchoring of glucose molecules leading to a perturbing influence of the asymmetric chiral environment. Copyright © 2013 Elsevier Inc. All rights reserved.

Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

PubMed

Harada, Kazuki; Maeda, Toshimichi; Hasegawa, Yoshiro; Tokunaga, Takushi; Ogawa, Shinya; Fukuda, Kyoko; Nagatsuka, Norie; Nagao, Keiko; Ueno, Shunshiro

2011-01-01

The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

A new spectroscopic calibration to determine Teff and [Fe/H] of FGK dwarfs and giants

NASA Astrophysics Data System (ADS)

Teixeira, G. D. C.; Sousa, S. G.; Tsantaki, M.; Monteiro, M. J. P. F. G.; Santos, N. C.; Israelian, G.

2017-10-01

We present a new spectroscopic calibration for a fast estimate of Teff and [Fe/H] for FGK dwarfs and GK giant stars. We used spectra from a joint sample of 708 stars, composed by 451 FGK dwarfs and 257 GK-giant stars with homogeneously determined spectroscopic stellar parameters. We have derived 322 EW line-ratios and 100 FeI lines that can be used to compute Teff and [Fe/H], respectively. We show that these calibrations are effective for FGK dwarfs and GK-giant stars in the following ranges: 4500 K < Teff < 6500 K, 2.5 < log g < 4.9 dex, and -0.8 < [Fe/H] < 0:5 dex. The new calibration has a standard deviation of 74 K for Teff and 0.07 dex for [Fe/H]. We use four independent samples of stars to test and verify the new calibration, a sample of giant stars, a sample composed of Gaia FGK benchmark stars, a sample of GK-giant stars from the DR1 of the Gaia-ESO survey, and a sample of FGK-dwarf stars. We present a new computer code, GeTCal, for automatically producing new calibration files based on any new sample of stars.

Investigating Vaporization of Silica through Laser Driven Shock Wave Experiments

NASA Astrophysics Data System (ADS)

Kraus, R. G.; Swift, D. C.; Stewart, S. T.; Smith, R.; Bolme, C. A.; Spaulding, D. K.; Hicks, D.; Eggert, J.; Collins, G.

2010-12-01

Giant impacts melt and vaporize a significant amount of the bolide and target body. However, our ability to determine how much melt or vapor a given impact creates depends strongly on our understanding of the liquid-vapor phase boundary of geologic materials. Our current knowledge of the liquid-vapor equilibrium for one of the most important minerals, SiO2, is rather limited due to the difficulty of performing experiments in this area of phase space. In this study, we investigate the liquid-vapor coexistence region by shocking quartz into a supercritical fluid state and allowing it to adiabatically expand to a state on the liquid-vapor phase boundary. Although shock compression and release has been used to study the liquid-vapor equilibrium of metals [1], few attempts have been made at studying geologic materials by this method [2]. Shock waves were produced by direct ablation of the quartz sample using the Jupiter Laser Facility of Lawrence Livermore National Laboratory. Steady shock pressures of 120-360 GPa were produced in the quartz samples: high enough to force the quartz into a supercritical fluid state. As the shock wave propagates through the sample, we measure the shock velocity using a line imaging velocity interferometer system for any reflector (VISAR) and shock temperature using a streaked optical pyrometer (SOP). When the shock wave reaches the free surface of the sample, the material adiabatically expands. Upon breakout of the shock at the free surface, the SOP records a distinct drop in radiance due to the lower temperature of the expanded material. For a subset of experiments, a LiF window is positioned downrange of the expanding silica. When the expanding silica impacts the LiF window, the velocity at the interface between the expanding silica and LiF window is measured using the VISAR. From the shock velocity measurements, we accurately determine the shocked state in the quartz. The post-shock radiance measurements are used to constrain the temperature on the liquid-vapor phase boundary (e.g., [3]) at much higher pressures than previously possible using a 2 stage gas gun [4, 5]. The density on the liquid-vapor phase boundary is constrained by comparing the velocity at the silica-LiF interface to numerical simulations that use equations of state with systematically varied liquid-vapor phase boundaries. We present the results within the context of understanding vaporization during giant impact events. [1] Brannon, R.M. and L.C. Chhabildas (1995) Int. J. Impact Engng. 17, 109-120. [2] Kurosawa, K. and S. Sugita (2010) J. Geophys. Res. in press. [3] Stewart, S.T., A. Seifter, and A.W. Obst (2008) Geophys. Res. Lett., 35, (23). [4] Lyzenga, G.A., T.J. Ahrens, and A.C. Mitchell (1983) J. Geophys. Res. , 88, (NB3), 2431-2444. [5] Boslough, M.B. (1988) J. Geophys. Res., 93, (B6), 6477-6484.

Liquid-vapor phase relations in the Si-O system: A calorically constrained van der Waals-type model

NASA Astrophysics Data System (ADS)

Connolly, James A. D.

2016-09-01

This work explores the use of several van der Waals (vW)-type equations of state (EoS) for predicting vaporous phase relations and speciation in the Si-O system, with emphasis on the azeotropic boiling curve of SiO2-rich liquid. Comparison with the observed Rb and Hg boiling curves demonstrates that prediction accuracy is improved if the a-parameter of the EoS, which characterizes vW forces, is constrained by ambient pressure heat capacities. All EoS considered accurately reproduce metal boiling curve trajectories, but absent knowledge of the true critical compressibility factor, critical temperatures remain uncertain by ~500 K. The EoS plausibly represent the termination of the azeotropic boiling curve of silica-rich liquid by a critical point across which the dominant Si oxidation state changes abruptly from the tetravalent state characteristic of the liquid to the divalent state characteristic of the vapor. The azeotropic composition diverges from silica toward metal-rich compositions with increasing temperature. Consequently, silica boiling is divariant and atmospheric loss after a giant impact would enrich residual silicate liquids in reduced silicon. Two major sources of uncertainty in the boiling curve prediction are the heat capacity of silica liquid, which may decay during depolymerization from the near-Dulong-Petit limit heat capacity of the ionic liquid to value characteristic of the molecular liquid, and the unknown liquid affinity of silicon monoxide. Extremal scenarios for these uncertainties yield critical temperatures and compositions of 5200-6200 K and Si1.1O2-Si1.4O2. The lowest critical temperatures are marginally consistent with shock experiments and are therefore considered more probable.

DISCOVERY OF RELATIVELY HYDROGEN-POOR GIANTS IN THE GALACTIC GLOBULAR CLUSTER ω CENTAURI

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

Hema, B. P.; Pandey, Gajendra, E-mail: hema@iiap.res.in, E-mail: pandey@iiap.res.in

2014-09-10

In this Letter, the results of our low-resolution spectroscopic survey for identifying hydrogen-deficient stars in the red giant sample of the globular cluster ω Cen are reported. Spectral analyses were carried out on the basis of the strengths of the (0, 0) MgH band and the Mg b triplet. In our sample, four giants were identified with weak/absent MgH bands in their observed spectra, which was unexpected for their well determined stellar parameters. The Mg abundances for the program stars were determined from the subordinate lines of the MgH band to the blue of the Mg b triplet, using the spectral synthesis technique. Themore » derived Mg abundances for the program stars were as expected for the red giants of ω Cen, except for the four identified candidates. The determined Mg abundances of these four candidates are much lower than that expected for the red giants of ω Cen, and are unacceptable based on the strengths of the Mg b triplet in their observed spectra. Hence, a plausible explanation for the weak/absent MgH bands in the observed spectra of these stars is a relatively lower abundance of hydrogen in their atmospheres. These giants may belong to the group of helium-enriched red giants of ω Cen.« less

Why does the giant panda eat bamboo? A comparative analysis of appetite-reward-related genes among mammals.

PubMed

Jin, Ke; Xue, Chenyi; Wu, Xiaoli; Qian, Jinyi; Zhu, Yong; Yang, Zhen; Yonezawa, Takahiro; Crabbe, M James C; Cao, Ying; Hasegawa, Masami; Zhong, Yang; Zheng, Yufang

2011-01-01

The giant panda has an interesting bamboo diet unlike the other species in the order of Carnivora. The umami taste receptor gene T1R1 has been identified as a pseudogene during its genome sequencing project and confirmed using a different giant panda sample. The estimated mutation time for this gene is about 4.2 Myr. Such mutation coincided with the giant panda's dietary change and also reinforced its herbivorous life style. However, as this gene is preserved in herbivores such as cow and horse, we need to look for other reasons behind the giant panda's diet switch. Since taste is part of the reward properties of food related to its energy and nutrition contents, we did a systematic analysis on those genes involved in the appetite-reward system for the giant panda. We extracted the giant panda sequence information for those genes and compared with the human sequence first and then with seven other species including chimpanzee, mouse, rat, dog, cat, horse, and cow. Orthologs in panda were further analyzed based on the coding region, Kozak consensus sequence, and potential microRNA binding of those genes. Our results revealed an interesting dopamine metabolic involvement in the panda's food choice. This finding suggests a new direction for molecular evolution studies behind the panda's dietary switch.

Why Does the Giant Panda Eat Bamboo? A Comparative Analysis of Appetite-Reward-Related Genes among Mammals

PubMed Central

Jin, Ke; Xue, Chenyi; Wu, Xiaoli; Qian, Jinyi; Zhu, Yong; Yang, Zhen; Yonezawa, Takahiro; Crabbe, M. James C.; Cao, Ying; Hasegawa, Masami; Zhong, Yang; Zheng, Yufang

2011-01-01

Background The giant panda has an interesting bamboo diet unlike the other species in the order of Carnivora. The umami taste receptor gene T1R1 has been identified as a pseudogene during its genome sequencing project and confirmed using a different giant panda sample. The estimated mutation time for this gene is about 4.2 Myr. Such mutation coincided with the giant panda's dietary change and also reinforced its herbivorous life style. However, as this gene is preserved in herbivores such as cow and horse, we need to look for other reasons behind the giant panda's diet switch. Methodology/Principal Findings Since taste is part of the reward properties of food related to its energy and nutrition contents, we did a systematic analysis on those genes involved in the appetite-reward system for the giant panda. We extracted the giant panda sequence information for those genes and compared with the human sequence first and then with seven other species including chimpanzee, mouse, rat, dog, cat, horse, and cow. Orthologs in panda were further analyzed based on the coding region, Kozak consensus sequence, and potential microRNA binding of those genes. Conclusions/Significance Our results revealed an interesting dopamine metabolic involvement in the panda's food choice. This finding suggests a new direction for molecular evolution studies behind the panda's dietary switch. PMID:21818345

Effects of two citrus-based commercial herbicides on giant reed, Arundo donax L. (Poaceae)

USDA-ARS?s Scientific Manuscript database

The giant reed, Arundo donax L. (Poaceae), is an invasive weed pest in the United States and other parts of the world, particularly in riparian habitats where it can hinder the flow of water and choke out indigenous vegetation. Conventional approaches to controlling A. donax have not been particular...

CARBON ABUNDANCES FOR RED GIANTS IN THE DRACO DWARF SPHEROIDAL GALAXY

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

Shetrone, Matthew D.; Stanford, Laura M.; Smith, Graeme H.

2013-05-15

Measurements of [C/Fe], [Ca/H], and [Fe/H] have been derived from Keck I LRISb spectra of 35 giants in the Draco dwarf spheroidal galaxy. The iron abundances are derived by a spectrum synthesis modeling of the wavelength region from 4850 to 5375 A, while calcium and carbon abundances are obtained by fitting the Ca II H and K lines and the CH G band, respectively. A range in metallicity of -2.9 {<=} [Fe/H] {<=} -1.6 is found within the giants sampled, with a good correlation between [Fe/H] and [Ca/H]. The great majority of stars in the sample would be classified asmore » having weak absorption in the {lambda}3883 CN band, with only a small scatter in band strengths at a given luminosity on the red giant branch. In this sense the behavior of CN among the Draco giants is consistent with the predominantly weak CN bands found among red giants in globular clusters of metallicity [Fe/H] < -1.8. Over half of the giants in the Draco sample have [Fe/H] > -2.25, and among these there is a trend for the [C/Fe] abundance to decrease with increasing luminosity on the red giant branch. This is a phenomenon that is also seen among both field and globular cluster giants of the Galactic halo, where it has been interpreted as a consequence of deep mixing of material between the base of the convective envelope and the outer limits of the hydrogen-burning shell. However, among the six Draco giants observed that turn out to have metallicities -2.65 < [Fe/H] < -2.25 there is no such trend seen in the carbon abundance. This may be due to small sample statistics or primordial inhomogeneities in carbon abundance among the most metal-poor Draco stars. We identify a potential carbon-rich extremely metal-poor star in our sample. This candidate will require follow-up observations for confirmation.« less

Giant magnetoimpedance-based microchannel system for quick and parallel genotyping of human papilloma virus type 16/18

NASA Astrophysics Data System (ADS)

Yang, Hao; Chen, Lei; Lei, Chong; Zhang, Ju; Li, Ding; Zhou, Zhi-Min; Bao, Chen-Chen; Hu, Heng-Yao; Chen, Xiang; Cui, Feng; Zhang, Shuang-Xi; Zhou, Yong; Cui, Da-Xiang

2010-07-01

Quick and parallel genotyping of human papilloma virus (HPV) type 16/18 is carried out by a specially designed giant magnetoimpedance (GMI) based microchannel system. Micropatterned soft magnetic ribbon exhibiting large GMI ratio serves as the biosensor element. HPV genotyping can be determined by the changes in GMI ratio in corresponding detection region after hybridization. The result shows that this system has great potential in future clinical diagnostics and can be easily extended to other biomedical applications based on molecular recognition.

Timescales of Quartz Crystallization and the Longevity of the Bishop Giant Magma Body

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

Gualda, Guilherme A.R.; Pamukcu, Ayla S.; Ghiorso, Mark S.

Supereruptions violently transfer huge amounts (100 s-1000 s km{sup 3}) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted {approx}760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain themore » timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500-3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies.« less

Patterns of genetic differentiation at MHC class I genes and microsatellites identify conservation units in the giant panda.

PubMed

Zhu, Ying; Wan, Qiu-Hong; Yu, Bin; Ge, Yun-Fa; Fang, Sheng-Guo

2013-10-22

Evaluating patterns of genetic variation is important to identify conservation units (i.e., evolutionarily significant units [ESUs], management units [MUs], and adaptive units [AUs]) in endangered species. While neutral markers could be used to infer population history, their application in the estimation of adaptive variation is limited. The capacity to adapt to various environments is vital for the long-term survival of endangered species. Hence, analysis of adaptive loci, such as the major histocompatibility complex (MHC) genes, is critical for conservation genetics studies. Here, we investigated 4 classical MHC class I genes (Aime-C, Aime-F, Aime-I, and Aime-L) and 8 microsatellites to infer patterns of genetic variation in the giant panda (Ailuropoda melanoleuca) and to further define conservation units. Overall, we identified 24 haplotypes (9 for Aime-C, 1 for Aime-F, 7 for Aime-I, and 7 for Aime-L) from 218 individuals obtained from 6 populations of giant panda. We found that the Xiaoxiangling population had the highest genetic variation at microsatellites among the 6 giant panda populations and higher genetic variation at Aime-MHC class I genes than other larger populations (Qinling, Qionglai, and Minshan populations). Differentiation index (FST)-based phylogenetic and Bayesian clustering analyses for Aime-MHC-I and microsatellite loci both supported that most populations were highly differentiated. The Qinling population was the most genetically differentiated. The giant panda showed a relatively higher level of genetic diversity at MHC class I genes compared with endangered felids. Using all of the loci, we found that the 6 giant panda populations fell into 2 ESUs: Qinling and non-Qinling populations. We defined 3 MUs based on microsatellites: Qinling, Minshan-Qionglai, and Daxiangling-Xiaoxiangling-Liangshan. We also recommended 3 possible AUs based on MHC loci: Qinling, Minshan-Qionglai, and Daxiangling-Xiaoxiangling-Liangshan. Furthermore, we recommend that a captive breeding program be considered for the Qinling panda population.

Vaporization of SiO2 and MgSiO3

NASA Astrophysics Data System (ADS)

Stixrude, L. P.; Xiao, B.

2016-12-01

Vaporization of SiO2 and MgSiO3B Xiaoa and L Stixrude*a, a Department of Earth Sciences, University College London, WC1E 6BT London, UK *presenting author, email: l.stixrude@ucl.ac.uk Vaporization is an important process in Earth's earliest evolution during which giant impacts are thought to have produced a transient silicate atmosphere. As experimental data are very limited, little is known of the near-critical vaporization of Earth's major oxide components: MgO and SiO2. We have performed novel ab initio molecular dynamics simulations of vapor-liquid coexistence in the SiO2 and MgSiO3 systems. The simulations, based on density functional theory using the VASP code, begin with a suitably prepared liquid slab embedded in a vacuum. During the dynamical trajectory in the canonical ensemble, we see spontaneous vaporization, leading eventually to a steady-state chemical equilibrium between the two coexisting phases. We locate the liquid-vapor critical point at 6600 K and 0.40 g/cm3 for MgSiO3 and 5300 K and 0.43 g/cm3 for SiO2. By carefully examining the trajectories, we determine the composition and speciation of the vapor. For MgSiO3, We find that the vapor is significantly richer in Mg, O, and atomic (non-molecular) species than extrapolation of low-temperature experimental data has suggested. These results will have important implications for our understanding of the initial chemistry of the Earth and Moon and the initial thermal state of Earth.

Electron-hole liquid in semiconductors and low-dimensional structures

NASA Astrophysics Data System (ADS)

Sibeldin, N. N.

2017-11-01

The condensation of excitons into an electron-hole liquid (EHL) and the main EHL properties in bulk semiconductors and low-dimensional structures are considered. The EHL properties in bulk materials are discussed primarily in qualitative terms based on the experimental results obtained for germanium and silicon. Some of the experiments in which the main EHL thermodynamic parameters (density and binding energy) have been obtained are described and the basic factors that determine these parameters are considered. Topics covered include the effect of external perturbations (uniaxial strain and magnetic field) on EHL stability; phase diagrams for a nonequilibrium exciton-gas-EHL system; information on the size and concentration of electron-hole drops (EHDs) under various experimental conditions; the kinetics of exciton condensation and of recombination in the exciton-gas-EHD system; dynamic EHD properties and the motion of EHDs under the action of external forces; the properties of giant EHDs that form in potential wells produced by applying an inhomogeneous strain to the crystal; and effects associated with the drag of EHDs by nonequilibrium phonons (phonon wind), including the dynamics and formation of an anisotropic spatial structure of the EHD cloud. In discussing EHLs in low-dimensional structures, a number of studies are reviewed on the observation and experimental investigation of phenomena such as spatially indirect (dipolar) electron-hole and exciton (dielectric) liquids in GaAs/AlGaAs structures with double quantum wells (QWs), EHDs containing only a few electron-hole pairs (dropletons), EHLs in type-I silicon QWs, and spatially direct and dipolar EHLs in type-II silicon-germanium heterostructures.

Giant panda (Ailuropoda melanoleuca) population dynamics and bamboo (subfamily Bambusoideae) life history: a structured population approach to examining carrying capacity when the prey are semelparous

USGS Publications Warehouse

Carter, J.; Ackleh, A.S.; Leonard, B.P.; Wang, Hongfang

1999-01-01

The giant panda, Ailuropoda melanoleuca, is a highly specialized Ursid whose diet consists almost entirely of various species of bamboo. Bamboo (Bambusoideae) is a grass subfamily whose species often exhibit a synchronous semelparity. Synchronous semelparity can create local drops in carrying capacity for the panda. We modeled the interaction of pandas and their bamboo food resources with an age structured panda population model linked to a natural history model of bamboo biomass dynamics based on literature values of bamboo biomass, and giant panda life history dynamics. This paper reports the results of our examination of the interaction between pandas and their bamboo food resource and its implications for panda conservation. In the model all panda populations were well below the carrying capacity of the habitat. The giant panda populations growth was most sensitive to changes in birth rates and removal of reproductive aged individuals. Periodic starvation that has been documented in conjunction with bamboo die-offs is probably related to the inability to move to other areas within the region where bamboo is still available. Based on the results of this model, giant panda conservation should concentrate on keeping breeding individuals in the wild, keep corridors to different bamboo species open to pandas, and to concentrate research on bamboo life history.

The role of membrane fluidization in the gel-assisted formation of giant polymersomes

DOE PAGES

Greene, Adrienne C.; Henderson, Ian M.; Gomez, Andrew; ...

2016-07-13

Polymersomes are being widely explored as synthetic analogs of lipid vesicles based on their enhanced stability and potential uses in a wide variety of applications in (e.g., drug delivery, cell analogs, etc.). Controlled formation of giant polymersomes for use in membrane studies and cell mimetic systems, however, is currently limited by low-yield production methodologies. Here, we describe for the first time, how the size distribution of giant poly(ethylene glycol)-poly(butadiene) (PEO-PBD) polymersomes formed by gel-assisted rehydration may be controlled based on membrane fluidization. We first show that the average diameter and size distribution of PEO-PBD polymersomes may be readily increased bymore » increasing the temperature of the rehydration solution. Further, we describe a correlative relationship between polymersome size and membrane fluidization through the addition of sucrose during rehydration, enabling the formation of PEO-PBD polymersomes with a range of diameters, including giant-sized vesicles (>100 μm). This correlative relationship suggests that sucrose may function as a small molecule fluidizer during rehydration, enhancing polymer diffusivity during formation and increasing polymersome size. Altogether the ability to easily regulate the size of PEO-PBD polymersomes based on membrane fluidity, either through temperature or fluidizers, has broadly applicability in areas including targeted therapeutic delivery and synthetic biology.« less

Membrane Bending Moduli of Coexisting Liquid Phases Containing Transmembrane Peptide.

PubMed

Usery, Rebecca D; Enoki, Thais A; Wickramasinghe, Sanjula P; Nguyen, V P; Ackerman, David G; Greathouse, Denise V; Koeppe, Roger E; Barrera, Francisco N; Feigenson, Gerald W

2018-05-08

A number of highly curved membranes in vivo, such as epithelial cell microvilli, have the relatively high sphingolipid content associated with "raft-like" composition. Given the much lower bending energy measured for bilayers with "nonraft" low sphingomyelin and low cholesterol content, observing high curvature for presumably more rigid compositions seems counterintuitive. To understand this behavior, we measured membrane rigidity by fluctuation analysis of giant unilamellar vesicles. We found that including a transmembrane helical GWALP peptide increases the membrane bending modulus of the liquid-disordered (Ld) phase. We observed this increase at both low-cholesterol fraction and higher, more physiological cholesterol fraction. We find that simplified, commonly used Ld and liquid-ordered (Lo) phases are not representative of those that coexist. When Ld and Lo phases coexist, GWALP peptide favors the Ld phase with a partition coefficient of 3-10 depending on mixture composition. In model membranes at high cholesterol fractions, Ld phases with GWALP have greater bending moduli than the Lo phase that would coexist. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Updating strategies for isolating and discovering giant viruses.

PubMed

Khalil, Jacques Yaacoub Bou; Andreani, Julien; La Scola, Bernard

2016-06-01

Almost fifteen years ago, the discovery of Acanthamoeba polyphaga mimivirus, the first giant virus, changed how we define a virus. It was discovered incidentally in a process of isolating Legionella sp. from environmental samples in the context of pneumonia epidemics using a co-culture system with Acanthamoeba. Since then, much effort and improvement has been put into the original technique. In addition to the known families of Mimiviridae and Marseilleviridae, four new proposed families of giant viruses have been isolated: Pandoravirus, Pithovirus, Faustovirus and Mollivirus. Major improvements were based on enrichment systems, targeted use of antibiotics and high-throughput methods. The most recent development, using flow cytometry for isolation and presumptive identification systems, opens a path to large environmental surveys that may discover new giant virus families in new protozoa supports used for culture support. Copyright © 2016 Elsevier Ltd. All rights reserved.

Should the Endangered Status of the Giant Panda Really Be Reduced? The Case of Giant Panda Conservation in Sichuan, China

PubMed Central

Ma, Ben; Lei, Shuo; Qing, Qin; Wen, Yali

2018-01-01

Simple Summary This study evaluates the effect of local, regional, and global factors on the recovery of giant panda populations and their habitat, questioning the recent downgrading in the conservation status of this iconic species. We highlight the actions taken over the last decade, which were primarily local scale changes and efforts for protecting pandas. Broader regional development and global climate change are expected to negatively affect current population trends in the long-term; this phenomenon has been documented in other wildlife populations also showing a recent recovery. Thus, we call for a revision of the assessments stipulated by the International Union for Conservation of Nature to incorporate broader potential impacts in predicting the future survival of threatened populations, thereby, ensuring that appropriate and objective protection measures are implemented well in advance. Abstract The International Union for Conservation of Nature (IUCN) reduced the threat status of the giant panda from “endangered” to “vulnerable” in September 2016. In this study, we analyzed current practices for giant panda conservation at regional and local environmental scales, based on recent reports of giant panda protection efforts in Sichuan Province, China, combined with the survey results from 927 households within and adjacent to the giant panda reserves in this area. The results showed that household attitudes were very positive regarding giant panda protection efforts. Over the last 10 years, farmers’ dependence on the natural resources provided by giant panda reserves significantly decreased. However, socio-economic development increased resource consumption, and led to climate change, habitat fragmentation, environmental pollution, and other issues that placed increased pressure on giant panda populations. This difference between local and regional scales must be considered when evaluating the IUCN status of giant pandas. While the status of this species has improved in the short-term due to positive local attitudes, large-scale socio-economic development pressure could have long-term negative impacts. Consequently, the IUCN assessment leading to the classification of giant panda as “vulnerable” instead of “endangered”, should not affect its conservation intensity and effort, as such actions could negatively impact population recovery efforts, leading to the extinction of this charismatic species. PMID:29751488

Structural link between giant molybdenum oxide based ions and derived Keggin structure: modular assemblies based on the [BW11O39]9- ion and pentagonal {M'M5} units (M' = W; M = Mo,W).

PubMed

Leclerc-Laronze, Nathalie; Marrot, Jérôme; Thouvenot, René; Cadot, Emmanuel

2009-01-01

Linked to the Pentagon: The addition of molybdate to [HBW(11)O(39)](8-) ions leads to the formation of mixed pentagonal units {W(Mo(5))} and {W(WMo(4))} trapped as linkers in the resulting modular assemblies, thus establishing the first link between the conventional Keggin ion derivatives and the giant molybdenum oxide and keplerate ions.

Methyl-β-cyclodextrins preferentially remove cholesterol from the liquid disordered phase in giant unilamellar vesicles.

PubMed

Sanchez, Susana A; Gunther, German; Tricerri, Maria A; Gratton, Enrico

2011-05-01

Methyl-β-cyclodextrins (MβCDs) are molecules that are extensively used to remove and to load cholesterol (Chol) from artificial and natural membranes; however, the mechanism of Chol extraction by MβCD from pure lipids or from complex mixtures is not fully understood. One of the outstanding questions in this field is the capability of MβCD to remove Chol from lipid domains having different packing. Here, we investigated the specificity of MβCD to remove Chol from coexisting macrodomains with different lipid packing. We used giant unilamellar vesicles (GUVs) made of 1,2-dioleoylphosphatidylcholine:1,2-dipalmitoylphatidylcholine:free cholesterol, 1:1:1 molar ratio at 27°C. Under these conditions, individual GUVs present Chol distributed into lo and ld phases. The two phases can be distinguished and visualized using Laurdan generalized polarization and two-photon excitation fluorescence microscopy. Our data indicate that MβCD removes Chol preferentially from the more disordered phase. The process of selective Chol removal is dependent on the MβCD concentration. At high concentrations, MβCD also removes phospholipids.

Three-dimensionally bonded spongy graphene material with super compressive elasticity and near-zero Poisson’s ratio

NASA Astrophysics Data System (ADS)

Wu, Yingpeng; Yi, Ningbo; Huang, Lu; Zhang, Tengfei; Fang, Shaoli; Chang, Huicong; Li, Na; Oh, Jiyoung; Lee, Jae Ah; Kozlov, Mikhail; Chipara, Alin C.; Terrones, Humberto; Xiao, Peishuang; Long, Guankui; Huang, Yi; Zhang, Fan; Zhang, Long; Lepró, Xavier; Haines, Carter; Lima, Márcio Dias; Lopez, Nestor Perea; Rajukumar, Lakshmy P.; Elias, Ana L.; Feng, Simin; Kim, Seon Jeong; Narayanan, N. T.; Ajayan, Pulickel M.; Terrones, Mauricio; Aliev, Ali; Chu, Pengfei; Zhang, Zhong; Baughman, Ray H.; Chen, Yongsheng

2015-01-01

It is a challenge to fabricate graphene bulk materials with properties arising from the nature of individual graphene sheets, and which assemble into monolithic three-dimensional structures. Here we report the scalable self-assembly of randomly oriented graphene sheets into additive-free, essentially homogenous graphene sponge materials that provide a combination of both cork-like and rubber-like properties. These graphene sponges, with densities similar to air, display Poisson’s ratios in all directions that are near-zero and largely strain-independent during reversible compression to giant strains. And at the same time, they function as enthalpic rubbers, which can recover up to 98% compression in air and 90% in liquids, and operate between -196 and 900 °C. Furthermore, these sponges provide reversible liquid absorption for hundreds of cycles and then discharge it within seconds, while still providing an effective near-zero Poisson’s ratio.

Three-dimensionally bonded spongy graphene material with super compressive elasticity and near-zero Poisson's ratio.

PubMed

Wu, Yingpeng; Yi, Ningbo; Huang, Lu; Zhang, Tengfei; Fang, Shaoli; Chang, Huicong; Li, Na; Oh, Jiyoung; Lee, Jae Ah; Kozlov, Mikhail; Chipara, Alin C; Terrones, Humberto; Xiao, Peishuang; Long, Guankui; Huang, Yi; Zhang, Fan; Zhang, Long; Lepró, Xavier; Haines, Carter; Lima, Márcio Dias; Lopez, Nestor Perea; Rajukumar, Lakshmy P; Elias, Ana L; Feng, Simin; Kim, Seon Jeong; Narayanan, N T; Ajayan, Pulickel M; Terrones, Mauricio; Aliev, Ali; Chu, Pengfei; Zhang, Zhong; Baughman, Ray H; Chen, Yongsheng

2015-01-20

It is a challenge to fabricate graphene bulk materials with properties arising from the nature of individual graphene sheets, and which assemble into monolithic three-dimensional structures. Here we report the scalable self-assembly of randomly oriented graphene sheets into additive-free, essentially homogenous graphene sponge materials that provide a combination of both cork-like and rubber-like properties. These graphene sponges, with densities similar to air, display Poisson's ratios in all directions that are near-zero and largely strain-independent during reversible compression to giant strains. And at the same time, they function as enthalpic rubbers, which can recover up to 98% compression in air and 90% in liquids, and operate between -196 and 900 °C. Furthermore, these sponges provide reversible liquid absorption for hundreds of cycles and then discharge it within seconds, while still providing an effective near-zero Poisson's ratio.

From Core to Solar Wind: Studying the Space Environment of Planets

NASA Astrophysics Data System (ADS)

Bagenal, F.

2004-05-01

Space physics permeates studies of the planets - from the magnetic field generated in a planetary core, through the charged particle bombardment of surfaces, the heating, excitation and ionization of an atmosphere or corona, to the acceleration of ions and electrons trapped in a planet's magnetosphere. This presentation provides an introductory overview of the space environment of planetary objects - from giant planets to tiny comets. The talk highlights three cases that illustrate the range of issues and applications of planetary space physics. (1) How has the solar wind interaction with Mars' strong, patchy remnant magnetization affected the loss of water? (2) How does the activity of volcanoes on Io trigger dynamics of the vast magnetosphere of Jupiter? (3) How could measurements of particles and fields by the Galileo spacecraft as it flew past Ganymede and Europa tell us that former has a liquid iron core and the latter a layer of liquid water?

Science and technology of stressed liquid crystals: display and non-display applications

NASA Astrophysics Data System (ADS)

Melnyk, Olha; Garbovskiy, Yuriy; Glushchenko, Anatoliy

2017-08-01

Stressed liquid crystals (SLCs) have emerged as promising tunable electro-optical materials more than a decade ago. They are optically transparent and are characterized by a giant phase modulation of the incident light (Nπ, N >> 1), fast (millisecond and shorter) electro-optical response, and a relatively low driving voltage (∼1 V/μm). Surprisingly, despite their advanced electro-optical performance, these new materials did not receive due attention in the research community. One possible reason of such an inadequate interest in SLCs is the lack of the well-documented procedure describing how to actually produce these materials. This paper is aimed at the development of such a step-by-step practical guide suitable for experimentalist and engineers. The proposed technology is applied to produce and characterize SLCs. In addition, some applications of the materials are briefly discussed and a broader overview of their possible use is outlined.

Design solutions for dome and main structure (mount) of giant telescopes

NASA Astrophysics Data System (ADS)

Murga, Gaizka; Bilbao, Armando; de Bilbao, Lander; Lorentz, Thomas E.

2016-07-01

During the last recent years, designs for several giant telescopes ranging from 20 to 40m in diameter are being developed: European Extremely Large Telescope Telescope (TMT). (E-ELT), Giant Magellan Telescope (GMT) and Thirty Meter It is evident that simple direct up-scaling of solutions that were more or less successful in the 8 to 10m class telescopes can not lead to viable designs for the future giant telescopes. New solutions are required to provide adequate load sharing, to cope with the large-scale derived deflections and to provide the required compliance, or to respond to structure-mechanism control interaction issues, among others. From IDOM experience in the development of the Dome and Main Structure of the European Extremely Large Telescope and our participation in some other giant telescopes, this paper reviews several design approaches for the main mechanisms and key structural parts of enclosures and mounts/main structures for giant telescopes, analyzing pros and cons of the different alternatives and outlining the preferred design schemes. The assessment is carried out mainly from a technical and performance-based angle but it also considers specific logistical issues for the assembly of these large telescopes in remote and space-limited areas, together with cost and schedule related issues.

The Lushan earthquake and the giant panda: impacts and conservation.

PubMed

Zhang, Zejun; Yuan, Shibin; Qi, Dunwu; Zhang, Mingchun

2014-06-01

Earthquakes not only result in a great loss of human life and property, but also have profound effects on the Earth's biodiversity. The Lushan earthquake occurred on 20 Apr 2013, with a magnitude of 7.0 and an intensity of 9.0 degrees. A distance of 17.0 km from its epicenter to the nearest distribution site of giant pandas recorded in the Third National Survey was determined. Making use of research on the Wenchuan earthquake (with a magnitude of 8.0), which occurred approximately 5 years ago, we briefly analyze the impacts of the Lushan earthquake on giant pandas and their habitat. An earthquake may interrupt ongoing behaviors of giant pandas and may also cause injury or death. In addition, an earthquake can damage conservation facilities for pandas, and result in further habitat fragmentation and degradation. However, from a historical point of view, the impacts of human activities on giant pandas and their habitat may, in fact, far outweigh those of natural disasters such as earthquakes. Measures taken to promote habitat restoration and conservation network reconstruction in earthquake-affected areas should be based on requirements of giant pandas, not those of humans. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Two New Super Li-rich Core He-burning Giants: A New Twist to the Long Tale of Li Enhancement in K Giants

NASA Astrophysics Data System (ADS)

Bharat Kumar, Yerra; Singh, Raghubar; Eswar Reddy, B.; Zhao, Gang

2018-05-01

In this Letter we report two new super Li-rich K giants, KIC2305930 and KIC12645107, with Li abundances exceeding that of the interstellar medium (ISM; A(Li) ≥ 3.2 dex). Importantly, both of the giants have been classified as core He-burning red clump (RC) stars based on asteroseismic data from Kepler mission. Also, both of the stars are found to be low mass (M ≈ 1.0 M ⊙), which, together with an evidence of their evolutionary status of being RC stars, implies that the stars have gone through both the luminosity bump and He-flash during their red giant branch (RGB) evolution. The stars’ large Li abundance and evolutionary phase suggest that Li enrichment occurred very recently, probably at the tip of the RGB either during He-flash, an immediate preceding event on the RGB, or by some kind of external event such as merger of an RGB star with white dwarf. The findings will provide critical constraints to theoretical models for understanding of Li enhancement origin in RGB stars.

Planetary Formation: From the Earth and Moon to Extrasolar Giant Planets

NASA Technical Reports Server (NTRS)

Lissauer, Jack; DeVincenzi, Donald (Technical Monitor)

1999-01-01

An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Specific issues to be discussed include: (1) how large a solid core is needed to initiate rapid accumulation of gas? (2) can giant planets form very close to stars? (3) could a giant impact leading to lunar formation have occurred approximately 100 million years after the condensation of the oldest meteorites?

Planetary Formation: From the Earth and Moon to Extrasolar Giant Planets

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

1999-01-01

An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases-such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Specific issues to be discussed include: (1) how large a solid core is needed to initiate rapid accumulation of gas? (2) can giant planets form very close to stars? (3) could a giant impact leading to lunar formation have occurred approx. 100 million years after the condensation of the oldest meteorites?

Scientific rationale for Uranus and Neptune in situ explorations

NASA Astrophysics Data System (ADS)

Mousis, O.; Atkinson, D. H.; Cavalié, T.; Fletcher, L. N.; Amato, M. J.; Aslam, S.; Ferri, F.; Renard, J.-B.; Spilker, T.; Venkatapathy, E.; Wurz, P.; Aplin, K.; Coustenis, A.; Deleuil, M.; Dobrijevic, M.; Fouchet, T.; Guillot, T.; Hartogh, P.; Hewagama, T.; Hofstadter, M. D.; Hue, V.; Hueso, R.; Lebreton, J.-P.; Lellouch, E.; Moses, J.; Orton, G. S.; Pearl, J. C.; Sánchez-Lavega, A.; Simon, A.; Venot, O.; Waite, J. H.; Achterberg, R. K.; Atreya, S.; Billebaud, F.; Blanc, M.; Borget, F.; Brugger, B.; Charnoz, S.; Chiavassa, T.; Cottini, V.; d'Hendecourt, L.; Danger, G.; Encrenaz, T.; Gorius, N. J. P.; Jorda, L.; Marty, B.; Moreno, R.; Morse, A.; Nixon, C.; Reh, K.; Ronnet, T.; Schmider, F.-X.; Sheridan, S.; Sotin, C.; Vernazza, P.; Villanueva, G. L.

2018-06-01

The ice giants Uranus and Neptune are the least understood class of planets in our solar system but the most frequently observed type of exoplanets. Presumed to have a small rocky core, a deep interior comprising ∼70% heavy elements surrounded by a more dilute outer envelope of H2 and He, Uranus and Neptune are fundamentally different from the better-explored gas giants Jupiter and Saturn. Because of the lack of dedicated exploration missions, our knowledge of the composition and atmospheric processes of these distant worlds is primarily derived from remote sensing from Earth-based observatories and space telescopes. As a result, Uranus's and Neptune's physical and atmospheric properties remain poorly constrained and their roles in the evolution of the Solar System not well understood. Exploration of an ice giant system is therefore a high-priority science objective as these systems (including the magnetosphere, satellites, rings, atmosphere, and interior) challenge our understanding of planetary formation and evolution. Here we describe the main scientific goals to be addressed by a future in situ exploration of an ice giant. An atmospheric entry probe targeting the 10-bar level, about 5 scale heights beneath the tropopause, would yield insight into two broad themes: i) the formation history of the ice giants and, in a broader extent, that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. In addition, possible mission concepts and partnerships are presented, and a strawman ice-giant probe payload is described. An ice-giant atmospheric probe could represent a significant ESA contribution to a future NASA ice-giant flagship mission.

Intra-specific competition (crowding) of giant sequoias (Sequoiadendron giganteum)

USGS Publications Warehouse

Stohlgren, Thomas J.

1993-01-01

Information on the size and location of 1916 giant sequoias (Sequoiadendron giganteum (Lindl.) Buchholz) in Muir Grove, Sequoia National Park, in the southern Sierra Nevada of California was used to assess intra-specific crowding. Study objectives were to: (1) determine which parameters associated with intra-specific competition (i.e. size and distance to nearest neighbor, crowding/root system area overlap, or number of neighbors) might be important in spatial pattern development, growth, and survivorship of established giant sequoias; (2) quantify the level of intra-specific crowding of different sized live sequoias based on a model of estimated overlapping root system areas (i.e. an index of relative crowding); (3) compare the level of intra-specific crowding of similarly sized live and dead giant sequoias (less than 30 cm diameter at breast height (dbh) at the time of inventory (1969). Mean distances to the nearest live giant sequoia neighbor were not significantly different (at α = 0.05) for live and dead sequoias in similar size classes. A zone of influence competition model (i.e. index of crowding) based on horizontal overlap of estimated root system areas was developed for 1753 live sequoias. The model, based only on the spatial arrangement of live sequoias, was then tested on dead sequoias of less than 30 cm dbh (n = 163 trees; also recorded in 1969). The dead sequoias had a significantly higher crowding index than 561 live trees of similar diameter. Results showed that dead sequoias of less than 16.6 cm dbh had a significantly greater mean number of live neighbors and mean crowding index than live sequoias of similar size. Intra-specific crowding may be an important mechanism in determining the spatial distribution of sequoias in old-growth forests.

[Giant aneurysm of posterior comunicating artery (PCoA) in cerebral panarteriography and CT angiography (CTA)].

PubMed

Jaźwiec, Przemysław; Chwiszczuk, Luiza; Sasiadek, Marek; Całka, Karol; Kuniej, Tomasz; Plucińska, Irena

2008-01-01

We present a case of 32-year-old woman, who was admitted to the Department of Neurology in the emergency mode, due to: instantaneous pupillary dilation (mydriasis), ptosis of the left eyeball and double vision. We performed plain CT, panarteriography of cerebral vessels, CT angiography with RT3D (volume-rendered three-dimensional) reconstruction images. On the base of imaging studies the diagnosis of giant saccular aneurysm of the left posterior communicating artery was established. The patient was operated on and the giant aneurysm of left posterior communicating artery was clipped, confirming radiological diagnosis. During operation and postoperative period no complications were noted.

Coordinated observations of interacting peculiar red giant binaries, 2

NASA Technical Reports Server (NTRS)

Ake, T.

1995-01-01

IUE and H alpha observations continued on a two-year program to monitor the UV variability of three interacting peculiar red giant (PRG) binaries, HD 59643 (C6,s), HD 35155 (S3/2), and HR 1105 (S3.5/2.5). All of these systems were suspected to involve accretion of material from the PRG to a white-dwarf secondary, based mainly on previous IUE investigations. They were primary candidates from earlier surveys of PRG's to test the hypothesis that the Tc-poor PRG's are formed as a result of mass transfer from a secondary component rather than from internal thermal pulsing while on the asymptotic red giant branch.

Coordinated observations of interacting peculiar red giant binaries, 1

NASA Technical Reports Server (NTRS)

Ake, T.

1995-01-01

IUE Observations were begun for a two-year program to monitor the UV variability of three interacting peculiar red giant (PRG) binaries, HD 59643 (C6,s) HD 35155 (S3/2), and HR 1105 (S3.5/2.5). All of these systems were suspected to involve accretion of material from the PRG to a white-dwarf secondary, based mainly on previous IUE investigations. From our earlier surveys of PRG's, they were primary candidates to test the hypothesis that Tc-poor PRG's are formed as a result of mass transfer from a secondary component rather than from internal thermal pulsing while on the asymptotic red giant branch.

Analyzing the spatial positioning of nuclei in polynuclear giant cells

NASA Astrophysics Data System (ADS)

Stange, Maike; Hintsche, Marius; Sachse, Kirsten; Gerhardt, Matthias; Valleriani, Angelo; Beta, Carsten

2017-11-01

How cells establish and maintain a well-defined size is a fundamental question of cell biology. Here we investigated to what extent the microtubule cytoskeleton can set a predefined cell size, independent of an enclosing cell membrane. We used electropulse-induced cell fusion to form giant multinuclear cells of the social amoeba Dictyostelium discoideum. Based on dual-color confocal imaging of cells that expressed fluorescent markers for the cell nucleus and the microtubules, we determined the subcellular distributions of nuclei and centrosomes in the giant cells. Our two- and three-dimensional imaging results showed that the positions of nuclei in giant cells do not fall onto a regular lattice. However, a comparison with model predictions for random positioning showed that the subcellular arrangement of nuclei maintains a low but still detectable degree of ordering. This can be explained by the steric requirements of the microtubule cytoskeleton, as confirmed by the effect of a microtubule degrading drug.

The tip of the Red Giant Branch as a Distance Indicator for Resolved Galaxies: II. Computer Simulations

NASA Technical Reports Server (NTRS)

Madore, B. F.; Freedman, W. L.

1994-01-01

Based on both empirical data for nearby galaxies, and on computer simulations, we show that measuring the position of the tip of the first-ascent red-giant branch (TRGB) provides a means of obtaining the distances to nearby galaxies with a precision and accuracy comparable to using Cepheids and/or RR Lyrae variables.

Development of pedigree classification using microsatellite and mitochondrial markers for Giant grouper broodstock (Epinephelus lanceolatus) management in Taiwan.

PubMed

Kuo, Hsiao-Che; Hsu, Hao-Hsuan; Chua, Chee Shin; Wang, Ting-Yu; Chen, Young-Mao; Chen, Tzong-Yueh

2014-04-30

Most giant groupers in the market are derived from inbred stock. Inbreeding can cause trait depression, compromising the animals' fitness and disease resistance, obligating farmers to apply increased amounts of drugs. In order to solve this problem, a pedigree classification method is needed. Here, microsatellite and mitochondrial DNA were used as genetic markers to analyze the genetic relationships among giant grouper broodstocks. The 776-bp fragment of high polymorphic mitochondrial D-loop sequence was selected for measuring sibling relatedness. In a sample of 118 giant groupers, 42 haplotypes were categorized, with nucleotide diversity (π) of 0.00773 and haplotype diversity (HD) of 0.983. Furthermore, microsatellites were used for investigation of parentage. Six out of 33 microsatellite loci were selected as markers based on having a high number of alleles and compliance with Hardy-Weinberg equilibrium. Microsatellite profiles based on these loci provide high variability with low combined non-exclusion probability, permitting practical use in aquaculture. The method described here could be used to improve grouper broodstock management and lower the chances of inbreeding. This approach is expected to lead to production of higher quality groupers with higher disease resistance, thereby reducing the need for drug application.

A Vision for Ice Giant Exploration

NASA Technical Reports Server (NTRS)

Hofstadter, M.; Simon, A.; Atreya, S.; Banfield, D.; Fortney, J.; Hayes, A.; Hedman, M.; Hospodarsky, G.; Mandt, K.; Masters, A.;

[Assessment of ecosystem in giant panda distribution area based on entropy method and coefficient of variation].

PubMed

Yan, Zhi Gang; Li, Jun Qing

2017-12-01

The areas of the habitat and bamboo forest, and the size of the giant panda wild population have greatly increased, while habitat fragmentation and local population isolation have also intensified in recent years. Accurate evaluation of ecosystem status of the panda in the giant panda distribution area is important for giant panda conservation. The ecosystems of the distribution area and six mountain ranges were subdivided into habitat and population subsystems based on the hie-rarchical system theory. Using the panda distribution area as the study area and the three national surveys as the time node, the evolution laws of ecosystems were studied using the entropy method, coefficient of variation, and correlation analysis. We found that with continuous improvement, some differences existed in the evolution and present situation of the ecosystems of six mountain ranges could be divided into three groups. Ecosystems classified into the same group showed many commonalities, and difference between the groups was considerable. Problems of habitat fragmentation and local population isolation became more serious, resulting in ecosystem degradation. Individuali-zed ecological protection measures should be formulated and implemented in accordance with the conditions in each mountain system to achieve the best results.

High surface magnetic field in red giants as a new signature of planet engulfment?

NASA Astrophysics Data System (ADS)

Privitera, Giovanni; Meynet, Georges; Eggenberger, Patrick; Georgy, Cyril; Ekström, Sylvia; Vidotto, Aline A.; Bianda, Michele; Villaver, Eva; ud-Doula, Asif

2016-09-01

Context. Red giant stars may engulf planets. This may increase the rotation rate of their convective envelope, which could lead to strong dynamo-triggered magnetic fields. Aims: We explore the possibility of generating magnetic fields in red giants that have gone through the process of a planet engulfment. We compare them with similar models that evolve without any planets. We discuss the impact of magnetic braking through stellar wind on the evolution of the surface velocity of the parent star. Methods: By studying rotating stellar models with and without planets and an empirical relation between the Rossby number and the surface magnetic field, we deduced the evolution of the surface magnetic field along the red giant branch. The effects of stellar wind magnetic braking were explored using a relation deduced from magnetohydrodynamics simulations. Results: The stellar evolution model of a red giant with 1.7 M⊙ without planet engulfment and with a time-averaged rotation velocity during the main sequence equal to 100 km s-1 shows a surface magnetic field triggered by convection that is stronger than 10 G only at the base of the red giant branch, that is, for gravities log g> 3. When a planet engulfment occurs, this magnetic field can also appear at much lower gravities, that is, at much higher luminosities along the red giant branch. The engulfment of a 15 MJ planet typically produces a dynamo-triggered magnetic field stronger than 10 G for gravities between 2.5 and 1.9. We show that for reasonable magnetic braking laws for the wind, the high surface velocity reached after a planet engulfment may be maintained sufficiently long to be observable. Conclusions: High surface magnetic fields for red giants in the upper part of the red giant branch are a strong indication of a planet engulfment or of an interaction with a companion. Our theory can be tested by observing fast-rotating red giants such as HD 31994, Tyc 0347-00762-1, Tyc 5904-00513-1, and Tyc 6054-01204-1 and by determining whether they show magnetic fields.

Resolving the Discrepancy of Distance to M60, a Giant Elliptical Galaxy in Virgo

NASA Astrophysics Data System (ADS)

Lee, Myung Gyoon; Jang, In Sung

2017-05-01

There is a well-known discrepancy in the distance estimation of M60, a giant elliptical galaxy in Virgo; the planetary nebula luminosity function (PNLF) distance moduli for this galaxy are, on average, 0.4 mag smaller than the values based on the surface brightness fluctuation (SBF) in the literature. We present photometry of the resolved stars in an outer field of M60 based on deep F775W and F850LP images in the Hubble Space Telescope obtained as part of the Pure Parallel Program in the archive. Detected stars are mostly old red giants in the halo of M60. With this photometry, we determine a distance to M60 using the tip of the red giant branch (TRGB). A TRGB is detected at F850LP{}{TRGB}=26.70+/- 0.06 mag, in the luminosity function of the red giants. This value corresponds to F814W{}0,{TRGB}=27.13+/- 0.06 mag and {{QT}}{TRGB}=27.04+/- 0.07 mag, where QT is a color-corrected F814W magnitude. From this we derive a distance modulus, {(m-M)}0=31.05+/- 0.07({ran}) +/- 0.06({sys}) (d=16.23+/- 0.50({ran})+/- 0.42({sys}) Mpc). This value is 0.3 mag larger than the PNLF distances and 0.1 mag smaller than the SBF distances in the previous studies, which indicates that the PNLF distances to M60 reported in the literature have larger uncertainties than the suggested values.

Kretzoiarctos gen. nov., the Oldest Member of the Giant Panda Clade

PubMed Central

Abella, Juan; Alba, David M.; Robles, Josep M.; Valenciano, Alberto; Rotgers, Cheyenn; Carmona, Raül; Montoya, Plinio; Morales, Jorge

2012-01-01

The phylogenetic position of the giant panda, Ailuropoda melanoleuca (Carnivora: Ursidae: Ailuropodinae), has been one of the most hotly debated topics by mammalian biologists and paleontologists during the last century. Based on molecular data, it is currently recognized as a true ursid, sister-taxon of the remaining extant bears, from which it would have diverged by the Early Miocene. However, from a paleobiogeographic and chronological perspective, the origin of the giant panda lineage has remained elusive due to the scarcity of the available Miocene fossil record. Until recently, the genus Ailurarctos from the Late Miocene of China (ca. 8–7 mya) was recognized as the oldest undoubted member of the Ailuropodinae, suggesting that the panda lineage might have originated from an Ursavus ancestor. The role of the purported ailuropodine Agriarctos, from the Miocene of Europe, in the origins of this clade has been generally dismissed due to the paucity of the available material. Here, we describe a new ailuropodine genus, Kretzoiarctos gen. nov., based on remains from two Middle Miocene (ca. 12–11 Ma) Spanish localities. A cladistic analysis of fossil and extant members of the Ursoidea confirms the inclusion of the new genus into the Ailuropodinae. Moreover, Kretzoiarctos precedes in time the previously-known, Late Miocene members of the giant panda clade from Eurasia (Agriarctos and Ailurarctos). The former can be therefore considered the oldest recorded member of the giant panda lineage, which has significant implications for understanding the origins of this clade from a paleobiogeographic viewpoint. PMID:23155439

Kretzoiarctos gen. nov., the oldest member of the giant panda clade.

PubMed

Abella, Juan; Alba, David M; Robles, Josep M; Valenciano, Alberto; Rotgers, Cheyenn; Carmona, Raül; Montoya, Plinio; Morales, Jorge

2012-01-01

The phylogenetic position of the giant panda, Ailuropoda melanoleuca (Carnivora: Ursidae: Ailuropodinae), has been one of the most hotly debated topics by mammalian biologists and paleontologists during the last century. Based on molecular data, it is currently recognized as a true ursid, sister-taxon of the remaining extant bears, from which it would have diverged by the Early Miocene. However, from a paleobiogeographic and chronological perspective, the origin of the giant panda lineage has remained elusive due to the scarcity of the available Miocene fossil record. Until recently, the genus Ailurarctos from the Late Miocene of China (ca. 8-7 mya) was recognized as the oldest undoubted member of the Ailuropodinae, suggesting that the panda lineage might have originated from an Ursavus ancestor. The role of the purported ailuropodine Agriarctos, from the Miocene of Europe, in the origins of this clade has been generally dismissed due to the paucity of the available material. Here, we describe a new ailuropodine genus, Kretzoiarctos gen. nov., based on remains from two Middle Miocene (ca. 12-11 Ma) Spanish localities. A cladistic analysis of fossil and extant members of the Ursoidea confirms the inclusion of the new genus into the Ailuropodinae. Moreover, Kretzoiarctos precedes in time the previously-known, Late Miocene members of the giant panda clade from Eurasia (Agriarctos and Ailurarctos). The former can be therefore considered the oldest recorded member of the giant panda lineage, which has significant implications for understanding the origins of this clade from a paleobiogeographic viewpoint.

Increased acidification in the rhizosphere of cactus seedlings induced by Azospirillum brasilense

NASA Astrophysics Data System (ADS)

Carrillo, Angel; Li, Ching; Bashan, Yoav

2002-08-01

Acidification of the rhizosphere of cactus seedlings (giant cardon, Pachycereus pringlei) after inoculation with the plant growth-promoting bacterium Azospirillum brasilense Cd, in the presence or absence of ammonium and nitrate, was studied to understand how to increase growth of cardon seedlings in poor desert soils. While ammonium enhanced rhizosphere and liquid culture acidification, inoculation with the bacteria enhanced it further. On the other hand, nitrate increased pH of the rhizosphere, but combined with the bacterial inoculation, increase in pH was significantly smaller. Bacterial inoculation with ammonium enhanced plant growth.

Growth of Walled Cells: From Shells to Vesicles

NASA Astrophysics Data System (ADS)

Boudaoud, Arezki

2003-07-01

The growth of isolated walled cells is investigated. Examples of such cells range from bacteria to giant algae, and include cochlear hair, plant root hair, fungi, and yeast cells. They are modeled as elastic shells containing a liquid. Cell growth is driven by fluid pressure and is is similar to a plastic deformation of the wall. The requirement of mechanical equilibrium leads to two new scaling laws for cell size that are in quantitative agreement with the compiled biological data. Given these results, possible shapes for growing cells are computed by analogy with those of vesicle membranes.

On the growth of walled cells: From shells to vesicles.

NASA Astrophysics Data System (ADS)

Boudaoud, Arezki

2003-03-01

The growth of isolated walled cells is investigated. Examples of such cells range from bacteria to giant algae, and include cochlear hair, plant root hair, fungi and yeast cells. They are modeled as elastic shells inflated by a liquid. Cell growth is driven by fluid pressure and is similar to a plastic deformation of the wall. The requirement of mechanical equilibrium leads to two new scaling laws for cell size that are in quantitative agreement with the compiled biological data. Given these results, possible shapes for growing cells are computed by analogy with those of vesicle membranes.

Statistical mechanics of light elements at high pressure. VI - Liquid-state calculations with Thomas-Fermi-Dirac theory

NASA Technical Reports Server (NTRS)

Macfarlane, J. J.

1984-01-01

A model free energy is developed for hydrogen-helium mixtures based on solid-state Thomas-Fermi-Dirac calculations at pressures relevant to the interiors of giant planets. Using a model potential similar to that for a two-component plasma, effective charges for the nuclei (which are in general smaller than the actual charges because of screening effects) are parameterized, being constrained by calculations at a number of densities, compositions, and lattice structures. These model potentials are then used to compute the equilibrium properties of H-He fluids using a charged hard-sphere model. The results find critical temperatures of about 0 K, 500 K, and 1500 K, for pressures of 10, 100, and 1000 Mbar, respectively. These phase separation temperatures are considerably lower (approximately 6,000-10,000 K) than those found from calculations using free electron perturbation theory, and suggest that H-He solutions should be stable against phase separation in the metallic zones of Jupiter and Saturn.

Giant amplification in degenerate band edge slow-wave structures interacting with an electron beam

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

Othman, Mohamed A. K.; Veysi, Mehdi; Capolino, Filippo

2016-03-15

We propose a new amplification regime based on a synchronous operation of four degenerate electromagnetic (EM) modes in a slow-wave structure and the electron beam, referred to as super synchronization. These four EM modes arise in a Fabry-Pérot cavity when degenerate band edge (DBE) condition is satisfied. The modes interact constructively with the electron beam resulting in superior amplification. In particular, much larger gains are achieved for smaller beam currents compared to conventional structures based on synchronization with only a single EM mode. We demonstrate giant gain scaling with respect to the length of the slow-wave structure compared to conventionalmore » Pierce type single mode traveling wave tube amplifiers. We construct a coupled transmission line model for a loaded waveguide slow-wave structure exhibiting a DBE, and investigate the phenomenon of giant gain via super synchronization using the Pierce model generalized to multimode interaction.« less

Hierarchical self-assembly, coassembly, and self-organization of novel liquid crystalline lattices and superlattices from a twin-tapered dendritic benzamide and its four-cylinder-bundle supramolecular polymer.

PubMed

Percec, Virgil; Bera, Tushar K; Glodde, Martin; Fu, Qiongying; Balagurusamy, Venkatachalapathy S K; Heiney, Paul A

2003-02-17

The synthesis and structural analysis of the twin-dendritic benzamide 10, based on the first-generation, self-assembling, tapered dendrons 3,4,5-tris(4'-dodecyloxybenzyloxy)benzoic acid and 3,4,5-tris(4'-dodecyloxybenzyloxy)-1-aminobenzene, and the polymethacrylate, 20, which contains 10 as side groups, are presented. Benzamide 10 self-assembles into a supramolecular cylindrical dendrimer that self-organizes into a columnar hexagonal (Phi(h)) liquid crystalline (LC) phase. Polymer 20 self-assembles into an imperfect four-cylinder-bundle supramolecular dendrimer, and creates a giant vesicular supercylinder that self-organizes into a columnar nematic (N(c)) LC phase which displays short-range hexagonal order. In mixtures of 20 and 10, 10 acts as a guest and 20 as a host to create a perfect four-cylinder-bundle host-guest supramolecular dendrimer that coorganizes with 10. A diversity of Phi(h), simple rectangular columnar (Phi(r-s)) and centered rectangular columnar (Phi(r-c)), superlattices are produced at different ratios between 20 and 10. This diversity of LC lattices and superlattices is facilitated by the architecture of the twin-dendritic building block, polymethacrylate, the host-guest supramolecular assembly, and by hydrogen bonding along the center of the supramolecular cylinders generated from 10 and 20.

Observationally Constraining Gas Giant Composition via Their Host Star Abundances

NASA Astrophysics Data System (ADS)

Teske, Johanna; Thorngren, Daniel; Fortney, Jonathan

2018-01-01

While the photospheric abundances of the Sun match many rock-forming elemental abundances in the Earth to within 10 mol%, as well as in Mars, the Moon, and meteorites, the Solar System giant planets are of distinctly non-stellar composition — Jupiter's bulk metallicity (inferred from its bulk density, measured from spacecraft data) is ∼ x5-10 solar, and Saturn is ∼ x10-20 solar. This knowledge has led to dramatic advances in understanding models of core accretion, which now match the heavy element enrichment of each of the Solar System's giant planets. However, we have thus far lacked similar data for exoplanets to use as a check for formation and composition models over a much larger parameter space. Here we present a study of the host stars of a sample of cool transiting gas giants with measured bulk metal fractions (as in Thorngren et al. 2016) to better constrain the relation Zplanet/Zstar — giant exoplanet metal enrichment relative to the host star. We add a new dimension of chemical variation, measuring C, O, Mg, Si, Ni, and well as Fe (on which previous Zplanet/Zstar calculations were based). Our analysis provides the best constraints to date on giant exoplanet interior composition and how this relates to formation environment, and make testable predictions for JWST observations of exoplanet atmospheres.

Detection of the Tip of Red Giant Branc in NGC 5128

NASA Technical Reports Server (NTRS)

Soria, Roberto; Mould, Jeremy R.; Watson, Alan M.; Gallagher, John S., III; Ballester, Gilda E.; Burrows, Christopher J.; Casertano, Stefano; Clarke, John T.; Crisp, David; Griffiths, Richard E.;

Optimal attributes for the object based detection of giant reed in riparian habitats: A comparative study between Airborne High Spatial Resolution and WorldView-2 imagery

NASA Astrophysics Data System (ADS)

Fernandes, Maria Rosário; Aguiar, Francisca C.; Silva, João M. N.; Ferreira, Maria Teresa; Pereira, José M. C.

2014-10-01

Giant reed is an aggressive invasive plant of riparian ecosystems in many sub-tropical and warm-temperate regions, including Mediterranean Europe. In this study we tested a set of geometric, spectral and textural attributes in an object based image analysis (OBIA) approach to map giant reed invasions in riparian habitats. Bagging Classification and Regression Tree were used to select the optimal attributes and to build the classification rules sets. Mapping accuracy was performed using landscape metrics and the Kappa coefficient to compare the topographical and geometric similarity between the giant reed patches obtained with the OBIA map and with a validation map derived from on-screen digitizing. The methodology was applied in two high spatial resolution images: an airborne multispectral imagery and the newly WorldView-2 imagery. A temporal coverage of the airborne multispectral images was radiometrically calibrated with the IR-Mad transformation and used to assess the influence of the phenological variability of the invader. We found that optimal attributes for giant reed OBIA detection are a combination of spectral, geometric and textural information, with different scoring selection depending on the spectral and spatial characteristics of the imagery. WorldView-2 showed higher mapping accuracy (Kappa coefficient of 77%) and spectral attributes, including the newly yellow band, were preferentially selected, although a tendency to overestimate the total invaded area, due to the low spatial resolution (2 m of pixel size vs. 50 cm) was observed. When airborne images were used, geometric attributes were primarily selected and a higher spatial detail of the invasive patches was obtained, due to the higher spatial resolution. However, in highly heterogeneous landscapes, the low spectral resolution of the airborne images (4 bands instead of the 8 of WorldView-2) reduces the capability to detect giant reed patches. Giant reed displays peculiar spectral and geometric traits, at leaf, canopy and stand level, which makes the OBIA approach a very suitable technique for management purposes.

On possible colonization of Ceres

NASA Astrophysics Data System (ADS)

Steklov, A. F.; Vidmachenko, A. P.

2018-05-01

Ceres is located between the planets of the terrestrial group, which are potentially amenable to terraforming, and the giant planets with their large satellites; to the latter we attribute Galilean satellites, Titan, Triton. These objects can be considered as permanent or transshipment bases for mastering the corresponding giant planets. Therefore Ceres can be considered as an intermediate base for interplanetary flights. Staying in the asteroid belt, Ceres can also become a base for the development of other asteroids and mining of mineral raw materials and ore minerals on them. It is believed that before settling of Ceres, it will be necessary to colonize the Moon and/or Mars.

Mars Habitability, Biosignature Preservation, and Mission Support

NASA Technical Reports Server (NTRS)

Oehler, Dorothy Z.; Allen, Carlton C.

2014-01-01

Our work has elucidated a new analog for the formation of giant polygons on Mars, involving fluid expulsion in a subaqueous environment. That work is based on three-dimensional (3D) seismic data on Earth that illustrate the mud volcanoes and giant polygons that result from sediment compaction in offshore settings. The description of this process has been published in the journal Icarus, where it will be part of a special volume on Martian analogs. These ideas have been carried further to suggest that giant polygons in the Martian lowlands may be the signature of an ancient ocean and, as such, could mark a region of enhanced habitability. A paper describing this hypothesis has been published in the journal Astrobiology.

Chronic Traumatic Giant Macular Hole Repair with Autologous Platelets.

PubMed

Coca, Mircea; Makkouk, Fuad; Picciani, Renata; Godley, Bernard; Elkeeb, Ahmed

2017-01-05

We report on the closure of a chronic posttraumatic giant macular hole. The patient presented with decreased vision in the left eye following blunt trauma 20 years prior. His dilated fundus examination revealed a 3000 um base-diameter full thickness macular hole. Surgical repair was performed with pars plana vitrectomy (PPV), internal limiting membrane peeling and autologous platelet concentrate (APC) injected over the macular hole. At one month follow-up, the macular hole had closed on exam and optical coherence tomography (OCT), and the patient reported subjective visual improvement. To our knowledge, this report presents the first case of a chronic giant macular hole successfully closed after undergoing surgery with adjuvant platelets therapy.

Planet Formation

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

1997-01-01

Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that most single stars should have rocky planets in orbit about them; the frequency of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Models for the formation of the giant planets found in recent radial velocity searches are discussed.

Chronic Traumatic Giant Macular Hole Repair with Autologous Platelets

PubMed Central

Makkouk, Fuad; Picciani, Renata; Godley, Bernard; Elkeeb, Ahmed

2017-01-01

We report on the closure of a chronic posttraumatic giant macular hole. The patient presented with decreased vision in the left eye following blunt trauma 20 years prior. His dilated fundus examination revealed a 3000 um base-diameter full thickness macular hole. Surgical repair was performed with pars plana vitrectomy (PPV), internal limiting membrane peeling and autologous platelet concentrate (APC) injected over the macular hole. At one month follow-up, the macular hole had closed on exam and optical coherence tomography (OCT), and the patient reported subjective visual improvement. To our knowledge, this report presents the first case of a chronic giant macular hole successfully closed after undergoing surgery with adjuvant platelets therapy. PMID:28168133

Analysis of the cytochrome c oxidase subunit II (COX2) gene in giant panda, Ailuropoda melanoleuca.

PubMed

Ling, S S; Zhu, Y; Lan, D; Li, D S; Pang, H Z; Wang, Y; Li, D Y; Wei, R P; Zhang, H M; Wang, C D; Hu, Y D

2017-01-23

The giant panda, Ailuropoda melanoleuca (Ursidae), has a unique bamboo-based diet; however, this low-energy intake has been sufficient to maintain the metabolic processes of this species since the fourth ice age. As mitochondria are the main sites for energy metabolism in animals, the protein-coding genes involved in mitochondrial respiratory chains, particularly cytochrome c oxidase subunit II (COX2), which is the rate-limiting enzyme in electron transfer, could play an important role in giant panda metabolism. Therefore, the present study aimed to isolate, sequence, and analyze the COX2 DNA from individuals kept at the Giant Panda Protection and Research Center, China, and compare these sequences with those of the other Ursidae family members. Multiple sequence alignment showed that the COX2 gene had three point mutations that defined three haplotypes, with 60% of the sequences corresponding to haplotype I. The neutrality tests revealed that the COX2 gene was conserved throughout evolution, and the maximum likelihood phylogenetic analysis, using homologous sequences from other Ursidae species, showed clustering of the COX2 sequences of giant pandas, suggesting that this gene evolved differently in them.

Formation of Outer Planets: Overview

NASA Technical Reports Server (NTRS)

Lissauer, Jack

2003-01-01

An overview of current theories of planetary formation, with emphasis on giant planets is presented. The most detailed models are based upon observation of our own Solar System and of young stars and their environments. Terrestrial planets are believe to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. According to the prevailing core instability model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk disspates. The primary questions regarding the core instability model is whether planets with small cores can accrete gaseous enveloples within the lifetimes of gaseous protoplanetary disks. The main alternative giant planet formation model is the disk instability model, in which gaseous planets form directly via gravitational instabilities within protoplanetary disks. Formation of giant planets via gas instability has never been demonstrated for realistic disk conditions. Moreover, this model has difficulty explaining the supersolar abundances of heavy elements in Jupiter and Saturn, and it does not explain the orgin of planets like Uranus and Neptune.

The magnetic fields at the surface of active single G-K giants

NASA Astrophysics Data System (ADS)

Aurière, M.; Konstantinova-Antova, R.; Charbonnel, C.; Wade, G. A.; Tsvetkova, S.; Petit, P.; Dintrans, B.; Drake, N. A.; Decressin, T.; Lagarde, N.; Donati, J.-F.; Roudier, T.; Lignières, F.; Schröder, K.-P.; Landstreet, J. D.; Lèbre, A.; Weiss, W. W.; Zahn, J.-P.

2015-02-01

Aims: We investigate the magnetic field at the surface of 48 red giants selected as promising for detection of Stokes V Zeeman signatures in their spectral lines. In our sample, 24 stars are identified from the literature as presenting moderate to strong signs of magnetic activity. An additional 7 stars are identified as those in which thermohaline mixing appears not to have occured, which could be due to hosting a strong magnetic field. Finally, we observed 17 additional very bright stars which enable a sensitive search to be performed with the spectropolarimetric technique. Methods: We use the spectropolarimeters Narval and ESPaDOnS to detect circular polarization within the photospheric absorption lines of our targets. We treat the spectropolarimetric data using the least-squares deconvolution method to create high signal-to-noise ratio mean Stokes V profiles. We also measure the classical S-index activity indicator for the Ca ii H&K lines, and the stellar radial velocity. To infer the evolutionary status of our giants and to interpret our results, we use state-of-the-art stellar evolutionary models with predictions of convective turnover times. Results: We unambiguously detect magnetic fields via Zeeman signatures in 29 of the 48 red giants in our sample. Zeeman signatures are found in all but one of the 24 red giants exhibiting signs of activity, as well as 6 out of 17 bright giant stars. However no detections were obtained in the 7 thermohaline deviant giants. The majority of the magnetically detected giants are either in the first dredge up phase or at the beginning of core He burning, i.e. phases when the convective turnover time is at a maximum: this corresponds to a "magnetic strip" for red giants in the Hertzsprung-Russell diagram. A close study of the 16 giants with known rotational periods shows that the measured magnetic field strength is tightly correlated with the rotational properties, namely to the rotational period and to the Rossby number Ro. Our results show that the magnetic fields of these giants are produced by a dynamo, possibly of α-ω origin since Ro is in general smaller than unity. Four stars for which the magnetic field is measured to be outstandingly strong with respect to that expected from the rotational period/magnetic field relation or their evolutionary status are interpreted as being probable descendants of magnetic Ap stars. In addition to the weak-field giant Pollux, 4 bright giants (Aldebaran, Alphard, Arcturus, η Psc) are detected with magnetic field strength at the sub-Gauss level. Besides Arcturus, these stars were not considered to be active giants before this study and are very similar in other respects to ordinary giants, with S-index indicating consistency with basal chromospheric flux. Tables 6-8 are available in electronic form at http://www.aanda.orgBased on observations obtained at the Télescope Bernard Lyot (TBL) at Observatoire du Pic du Midi, CNRS/INSU and Université de Toulouse, France, and at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, CNRS/INSU and the University of Hawaii.

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

Quintana, Elisa V.; Lissauer, Jack J., E-mail: elisa.quintana@nasa.gov

Models of planet formation have shown that giant planets have a large impact on the number, masses, and orbits of terrestrial planets that form. In addition, they play an important role in delivering volatiles from material that formed exterior to the snow line (the region in the disk beyond which water ice can condense) to the inner region of the disk where terrestrial planets can maintain liquid water on their surfaces. We present simulations of the late stages of terrestrial planet formation from a disk of protoplanets around a solar-type star and we include a massive planet (from 1 Mmore » {sub ⊕} to 1 M {sub J}) in Jupiter's orbit at ∼5.2 AU in all but one set of simulations. Two initial disk models are examined with the same mass distribution and total initial water content, but with different distributions of water content. We compare the accretion rates and final water mass fraction of the planets that form. Remarkably, all of the planets that formed in our simulations without giant planets were water-rich, showing that giant planet companions are not required to deliver volatiles to terrestrial planets in the habitable zone. In contrast, an outer planet at least several times the mass of Earth may be needed to clear distant regions of debris truncating the epoch of frequent large impacts. Observations of exoplanets from radial velocity surveys suggest that outer Jupiter-like planets may be scarce, therefore, the results presented here suggest that there may be more habitable planets residing in our galaxy than previously thought.« less

Experiments on the stability of metal diapirs

NASA Astrophysics Data System (ADS)

Wacheul, J. S.; Le Bars, M.; Aurnou, J. M.; Monteux, J.

2013-12-01

In the late stages of their accretions, telluric planets had most likely had a magma ocean because of numerous heat sources such as the important decay of radioactive elements and giant impacts. These giant impacts involved asteroid nearly as big as the moon, which were certainly differentiated. The core of these planetary embryos ultimately merged with the planets, but the amount of heat and chemicals they exchanged with the mantle during its passing through remains a widely open question. The question of the stability of an immiscible iron diapir falling through a magma ocean is essential for our understanding of these events. Thus, we have conducted the first experiments on an analogue system that involves liquid metal; we used liquid gallium as the melted iron and glycerol as the magma ocean. This set up allowed us to reach Reynolds numbers closer to the geophysical problem than other previous studies and accurate viscosity ratios. Using video analysis, we reconstruct the spectra of droplet sizes and velocities, from which we calculate a typical length of equilibration as a function of the diapir's radius. Our preliminary results are in agreement with the scenario of the iron rain concerning the droplet sizes, with a significant influence of the viscosity ratio on the maximal size of the droplets. However, the speed of these droplets seems to be controlled by the inertia of the whole flow in a sense that the relevant concept for the mixing between metal and silicate is turbulent mixing between miscible fluids. The influence of coalescence between droplets on this mixing, involving a significant part of the flow according to our experiment, is still to be quantified.

Self-Propelled Oil Droplets and Their Morphological Change to Giant Vesicles Induced by a Surfactant Solution at Low pH.

PubMed

Banno, Taisuke; Tanaka, Yuki; Asakura, Kouichi; Toyota, Taro

2016-09-20

Unique dynamics using inanimate molecular assemblies based on soft matter have drawn much attention for demonstrating far-from-equilibrium chemical systems. However, there are no soft matter systems that exhibit a possible pathway linking the self-propelled oil droplets to formation of giant vesicles stimulated by low pH. In this study, we conceived an experimental oil-in-water emulsion system in which flocculated particles composed of a imine-containing oil transformed to spherical oil droplets that self-propelled and, after coming to rest, formed membranous figures. Finally, these figures became giant vesicles. From NMR, pH curves, and surface tension measurements, we determined that this far-from-equilibrium phenomenon was due to the acidic hydrolysis of the oil, which produced a benzaldehyde derivative as an oil component and a primary amine as a surfactant precursor, and the dynamic behavior of the hydrolytic products in the emulsion system. These findings afforded us a potential linkage between mobile droplet-based protocells and vesicle-based protocells stimulated by low pH.

Development of Pedigree Classification Using Microsatellite and Mitochondrial Markers for Giant Grouper Broodstock (Epinephelus lanceolatus) Management in Taiwan

PubMed Central

Kuo, Hsiao-Che; Hsu, Hao-Hsuan; Chua, Chee Shin; Wang, Ting-Yu; Chen, Young-Mao; Chen, Tzong-Yueh

2014-01-01

Most giant groupers in the market are derived from inbred stock. Inbreeding can cause trait depression, compromising the animals’ fitness and disease resistance, obligating farmers to apply increased amounts of drugs. In order to solve this problem, a pedigree classification method is needed. Here, microsatellite and mitochondrial DNA were used as genetic markers to analyze the genetic relationships among giant grouper broodstocks. The 776-bp fragment of high polymorphic mitochondrial D-loop sequence was selected for measuring sibling relatedness. In a sample of 118 giant groupers, 42 haplotypes were categorized, with nucleotide diversity (π) of 0.00773 and haplotype diversity (HD) of 0.983. Furthermore, microsatellites were used for investigation of parentage. Six out of 33 microsatellite loci were selected as markers based on having a high number of alleles and compliance with Hardy-Weinberg equilibrium. Microsatellite profiles based on these loci provide high variability with low combined non-exclusion probability, permitting practical use in aquaculture. The method described here could be used to improve grouper broodstock management and lower the chances of inbreeding. This approach is expected to lead to production of higher quality groupers with higher disease resistance, thereby reducing the need for drug application. PMID:24796300

New potassium-sodium niobate lead-free piezoceramic: Giant-d33 vs. sintering temperature

NASA Astrophysics Data System (ADS)

Wu, Jiagang; Wang, Xiaopeng; Cheng, Xiaojing; Zheng, Ting; Zhang, Binyu; Xiao, Dingquan; Zhu, Jianguo; Lou, Xiaojie

2014-03-01

The objective of this work is to achieve a giant piezoelectric constant in (K,Na)NbO3-based lead-free ceramics, and then 0.96K0.46Na0.54Nb0.95Sb0.05O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 lead-free piezoceramics were designed and prepared by optimizing the sintering temperature (TS). The rhombohedral-tetragonal phase boundary is found in the ceramics sintered at 1070 ˜ 1105 °C and is suppressed when sintered at low TS of 1060 ˜ 1065 °C. The threshold for TS is 1070 °C in terms of their ferroelectric and piezoelectric properties owing to the difference in the phase boundary and the microstructure, and a large d33 of 388 ˜ 465 pC/N could be attained in a wide TS range of 1070 ˜ 1105 °C, benefiting their practical applications because of broad TS. More interestingly, the ceramic sintered at 1075 °C has a giant d33 of ˜465 pC/N. We think that such a giant d33 of this material system can benefit the development of (K,Na)NbO3-based piezoceramics.

CHEMICAL ABUNDANCES OF MEMBER STARS IN THE OPEN CLUSTER NGC 2632 (PRAESEPE)

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

Yang, X. L.; Chen, Y. Q.; Zhao, G.

2015-11-15

Based on high-resolution, high signal-to-noise ratio spectra, we present abundances of 17 elements (Fe, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Co, Ni, Y, Zr, Ba, La) for six stars (one Am star, one F dwarf star, and four GK giant stars) and radial velocities for 18 proper-motion selected member stars in the open cluster NGC 2632. In the Am star, s-process elements Y and Ba are clearly overabundant, which may be considered as an indicator of a peculiar Am star. The average [Fe/H] is 0.16 ± 0.06 from four GK giant member stars, which is similarmore » to that of solar-type stars in the literature. As compared with dwarf stars, significant overabundances are found for Na, Mg, and Ba elements in our giant stars, which can be explained by the evolutionary effect. We also detect a star-to-star scatter of [Na/Fe] ratios among four giants which locate approximately at the same position in the CMD. Finally, we perform an analysis on the possible connection between the abundance and spatial structure of NGC 2632, but we find no inhomogeneous abundance among different clumps of stars in this cluster based on our limited sample.« less

Analysis of the genetic diversity of the nematode parasite Baylisascaris schroederi from wild giant pandas in different mountain ranges in China.

PubMed

Zhou, Xuan; Xie, Yue; Zhang, Zhi-he; Wang, Cheng-dong; Sun, Yun; Gu, Xiao-bin; Wang, Shu-xian; Peng, Xue-rong; Yang, Guang-you

2013-08-08

Baylisascaris schroederi is one of the most common nematodes of the giant panda, and can cause severe baylisascarosis in both wild and captive giant pandas. Previous studies of the giant pandas indicated that this population is genetically distinct, implying the presence of a new subspecies. Based on the co-evolution between the parasite and the host, the aim of this study was to investigate the genetic differentiation in the B. schroederi population collected from giant pandas inhabiting different mountain ranges, and further to identify whether the evolution of this parasite correlates with the evolution of giant pandas. In this study, 48 B. schroederi were collected from 28 wild giant pandas inhabiting the Qinling, Minshan and Qionglai mountain ranges in China. The complete sequence of the mitochondrial cytochrome b (mtCytb) gene was amplified by PCR, and the corresponding population genetic diversity of the three mountain populations was determined. In addition, we discussed the evolutionary relationship between B. schroederi and its host giant panda. For the DNA dataset, insignificant Fst values and a significant, high level of gene flow were detected among the three mountain populations of B. schroederi, and high genetic variation within populations and a low genetic distance were observed. Both phylogenetic analyses and network mapping of the 16 haplotypes revealed a dispersed pattern and an absence of branches strictly corresponding to the three mountain range sampling sites. Neutrality tests and mismatch analysis indicated that B. schroederi experienced a population expansion in the past. Taken together, the dispersed haplotype map, extremely high gene flow among the three populations of B. schroederi, low genetic structure and rapid evolutionary rate suggest that the B. schroederi populations did not follow a pattern of isolation by distance, indicating the existence of physical connections before these populations became geographically separated.

Hertzsprung-Russell diagram and mass distribution of barium stars

NASA Astrophysics Data System (ADS)

Escorza, A.; Boffin, H. M. J.; Jorissen, A.; Van Eck, S.; Siess, L.; Van Winckel, H.; Karinkuzhi, D.; Shetye, S.; Pourbaix, D.

2017-12-01

With the availability of parallaxes provided by the Tycho-Gaia Astrometric Solution, it is possible to construct the Hertzsprung-Russell diagram (HRD) of barium and related stars with unprecedented accuracy. A direct result from the derived HRD is that subgiant CH stars occupy the same region as barium dwarfs, contrary to what their designations imply. By comparing the position of barium stars in the HRD with STAREVOL evolutionary tracks, it is possible to evaluate their masses, provided the metallicity is known. We used an average metallicity [Fe/H] = -0.25 and derived the mass distribution of barium giants. The distribution peaks around 2.5 M⊙ with a tail at higher masses up to 4.5 M⊙. This peak is also seen in the mass distribution of a sample of normal K and M giants used for comparison and is associated with stars located in the red clump. When we compare these mass distributions, we see a deficit of low-mass (1 - 2 M⊙) barium giants. This is probably because low-mass stars reach large radii at the tip of the red giant branch, which may have resulted in an early binary interaction. Among barium giants, the high-mass tail is however dominated by stars with barium indices of less than unity, based on a visual inspection of the barium spectral line; that is, these stars have a very moderate barium line strength. We believe that these stars are not genuine barium giants, but rather bright giants, or supergiants, where the barium lines are strengthened because of a positive luminosity effect. Moreover, contrary to previous claims, we do not see differences between the mass distributions of mild and strong barium giants. Full Table A.1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A100

GIANT IMPACT: AN EFFICIENT MECHANISM FOR THE DEVOLATILIZATION OF SUPER-EARTHS

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

Liu, Shang-Fei; Hori, Yasunori; Lin, D. N. C.

Mini-Neptunes and volatile-poor super-Earths coexist on adjacent orbits in proximity to host stars such as Kepler-36 and Kepler-11. Several post-formation processes have been proposed for explaining the origin of the compositional diversity between neighboring planets: mass loss via stellar XUV irradiation, degassing of accreted material, and in situ accumulation of the disk gas. Close-in planets are also likely to experience giant impacts during the advanced stage of planet formation. This study examines the possibility of transforming volatile-rich super-Earths/mini-Neptunes into volatile-depleted super-Earths through giant impacts. We present the results of three-dimensional hydrodynamic simulations of giant impacts in the accretionary and disruptivemore » regimes. Target planets are modeled with a three-layered structure composed of an iron core, silicate mantle, and hydrogen/helium envelope. In the disruptive case, the giant impact can remove most of the H/He atmosphere immediately and homogenize the refractory material in the planetary interior. In the accretionary case, the planet is able to retain more than half of the original gaseous envelope, while a compositional gradient suppresses efficient heat transfer as the planetary interior undergoes double-diffusive convection. After the giant impact, a hot and inflated planet cools and contracts slowly. The extended atmosphere enhances the mass loss via both a Parker wind induced by thermal pressure and hydrodynamic escape driven by the stellar XUV irradiation. As a result, the entire gaseous envelope is expected to be lost due to the combination of those processes in both cases. Based on our results, we propose that Kepler-36b may have been significantly devolatilized by giant impacts, while a substantial fraction of Kepler-36c’s atmosphere may remain intact. Furthermore, the stochastic nature of giant impacts may account for the observed large dispersion in the mass–radius relationship of close-in super-Earths and mini-Neptunes (at least to some extent)« less

[Giant splenic cyst in a teenager girl: Case report].

PubMed

Martínez Torres, Beatriz; Medina García, Manuel; Zafra Anta, Miguel Ángel; García Muñoz-Najar, Alejandro José; Tardío Dovao, Juan C

2017-06-01

Giant nonparasitic splenic epidermoid cysts are relatively uncommon. These lesions can lead abdominal pain, but most of then are asymptomatic, and they are discovered incidentally. We report a 13-y old female with a giant splenic epidermoid cystic, given the special interest of diagnostic and therapeutic decision-making of this rare entity. A 13-y old female with clinical history of abdominal pain since the last two months. On physical examination a firm, tender mass was palpable in left hypochondrium. Diagnosis of a large cystic splenic mass was made based on ultrasound and abdominal computed tomography scan. Splenectomy was performed, and histopathological-immunohistochemistry studies revealed findings suggestive of primary epithelial cyst. The post-operative clinical course was satisfactory and uneventful. Treatment of giant nonparasitic splenic cysts is surgical. Preserve splenic parenchyma must be the aim in an individualized decision-making. The different types of surgical modalities will be according to the diagnosis and clinical situation (cyst size, age, comorbidities).

Identification and properties of the M giant/X-ray system HD 154791 = 2A 1704+241

NASA Technical Reports Server (NTRS)

Garcia, M.; Baliunas, S. L.; Elvis, M.; Fabbiano, G.; Patterson, J.; Schwartz, D.; Doxsey, R.; Koenigsberger, G.; Swank, J.; Watson, M. G.

1983-01-01

The Aerial V X-ray source 2A 1704+241 (= 4U 1700+24 = 3A 1703+241) is identified with the M3 II star HD 154791. The identification is based on a precise X-ray position determined by the HEAO 1 scanning modulation collimator and the Einstein Observatory imaging proportional counter, together with a spectrum measured by the International Ultraviolet Explorer. The ultraviolet spectrum shows strong emission of C IV 1550 A, N v 1238 A, and Mg II 2800 A, which is very unusual among M giants. This is the first X-ray detection of an M giant which has a completely normal optical spectrum. The X-ray luminosity reaches three orders of magnitude above the mean upper limit for the coronal X-ray flux from M giants. Although there is no direct evidence for a binary system, since radial velocity variations have not been observed, it is shown that a plausible neutron star binary model can be constructed.

Ion association at discretely-charged dielectric interfaces: Giant charge inversion [Dielectric response controlled ion association at physically heterogeneous surfaces: Giant charge reversal

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

Wang, Zhi -Yong; Wu, Jianzhong

2017-07-11

Giant charge reversal has been identified for the first time by Monte Carlo simulation for a discretely charged surface in contact with a trivalent electrolyte solution. It takes place regardless of the surface charge density under study and the monovalent salt. In stark contrast to earlier predictions based on the 2-dimensional Wigner crystal model to describe strong correlation of counterions at the macroion surface, we find that giant charge reversal reflects an intricate interplay of ionic volume effects, electrostatic correlations, surface charge heterogeneity, and the dielectric response of the confined fluids. While the novel phenomenon is yet to be confirmedmore » with experiment, the simulation results appear in excellent agreement with a wide range of existing observations in the subregime of charge inversion. Lastly, our findings may have far-reaching implications to understanding complex electrochemical phenomena entailing ionic fluids under dielectric confinements.« less

Winds from Luminous Late-Type Stars: II. Broadband Frequency Distribution of Alfven Waves

NASA Technical Reports Server (NTRS)

Airapetian, V.; Carpenter, K. G.; Ofman, L.

2010-01-01

We present the numerical simulations of winds from evolved giant stars using a fully non-linear, time dependent 2.5-dimensional magnetohydrodynamic (MHD) code. This study extends our previous fully non-linear MHD wind simulations to include a broadband frequency spectrum of Alfven waves that drive winds from red giant stars. We calculated four Alfven wind models that cover the whole range of Alfven wave frequency spectrum to characterize the role of freely propagated and reflected Alfven waves in the gravitationally stratified atmosphere of a late-type giant star. Our simulations demonstrate that, unlike linear Alfven wave-driven wind models, a stellar wind model based on plasma acceleration due to broadband non-linear Alfven waves, can consistently reproduce the wide range of observed radial velocity profiles of the winds, their terminal velocities and the observed mass loss rates. Comparison of the calculated mass loss rates with the empirically determined mass loss rate for alpha Tau suggests an anisotropic and time-dependent nature of stellar winds from evolved giants.

KEPLER RAPIDLY ROTATING GIANT STARS

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

Costa, A. D.; Martins, B. L. Canto; Bravo, J. P.

2015-07-10

Rapidly rotating giant stars are relatively rare and may represent important stages of stellar evolution, resulting from stellar coalescence of close binary systems or accretion of substellar companions by their hosting stars. In the present Letter, we report 17 giant stars observed in the scope of the Kepler space mission exhibiting rapid rotation behavior. For the first time, the abnormal rotational behavior for this puzzling family of stars is revealed by direct measurements of rotation, namely from photometric rotation period, exhibiting a very short rotation period with values ranging from 13 to 55 days. This finding points to remarkable surfacemore » rotation rates, up to 18 times the rotation of the Sun. These giants are combined with six others recently listed in the literature for mid-infrared (IR) diagnostics based on Wide-field Infrared Survey Explorer information, from which a trend for an IR excess is revealed for at least one-half of the stars, but at a level far lower than the dust excess emission shown by planet-bearing main-sequence stars.« less

Polymorphism of follicle stimulating hormone beta (FSHβ) subunit gene and its association with litter traits in giant panda.

PubMed

Huang, Xiaoyu; Li, Desheng; Wang, Jiwen; Huang, Yan; Han, Chunchun; Zhang, Guiquan; Huang, Zhi; Wu, Honglin; Wei, Ming; Wang, Guosong; Hu, Haiping; Deng, Tao; He, Tao; Zhou, Yingming; Song, Shixian; Luo, Bo; Zhang, Heming

2013-11-01

The different SSCP patterns of the follicle stimulating hormone beta (FSHβ) gene amplified by three pairs of primers were sequenced. Comparisons among the three nucleotide sequences of three genotypes indicated that three base substitutions (A213T, A91G, and A89C) were detected in FSHβ gene, which A213T substitution led to one amino acids mutation (Lys > Met), and the other two substitutions were synonymous mutations. The AA, AB and BB genotypes patterns obtained by FSHβ primer1 had evident relation with the litter traits, but the SSCP genotypes patterns obtained by FSHβ primer2 and primer3 had no evident relation with the litter traits in giant panda. The giant panda with AA and AB genotype had the largest litter size and multiparity rate compared with the BB genotypes (P < 0.05). We speculated that the giant pandas with the A allele have better litter traits than those with the B allele.

Management of giant cell arteritis and polymyalgia rheumatica.

PubMed

Meskimen, S; Cook, T D; Blake, R L

2000-04-01

Giant cell arteritis and polymyalgia rheumatica are closely related disorders that affect persons more than 50 years of age and cause substantial morbidity. Patients with giant cell arteritis typically have a localized headache, nonspecific systemic symptoms, temporal artery tenderness and a high erythrocyte sedimentation rate (ESR). The diagnosis is confirmed by characteristic pathologic findings on temporal artery biopsy. Patients with polymyalgia rheumatica usually have similar nonspecific systemic symptoms, proximal muscle pain and stiffness, and an elevated ESR. The diagnosis is based on the clinical findings. Both disorders are treated with corticosteroids: high dosages for giant cell arteritis (prednisone in a dosage of 40 to 60 mg per day) and lower dosages for polymyalgia rheumatica (prednisone in a dosage of 10 to 20 mg per day). Symptom relief in response to treatment is rapid and reinforces the diagnosis. After normalization of the ESR, the corticosteroid is tapered, with the patient monitored closely for symptom recurrence. Most patients require corticosteroid therapy for two to three years and experience one or more treatment complications.

[Staged transcranial and transsphenoidal surgery for giant pituitary adenomas: a retrospective study of 21 cases].

PubMed

Liao, D Y; Liu, Z Y; Zhang, J; Ren, Q Q; Liu, X Y; Xu, J G

2018-05-08

Objective: To investigate the effect of the second-stage transcranial and transsphenoidal approach for giant pituitary tumors. Methods: A retrospective review of 21 patients, who had undergone the transcranial surgery and then transsphenoidal surgery for giant pituitary adenomas from 2012 to 2015 in the neurosurgery department of West China Hospital, was performed. Visual findings, endocrine presentation, complications, and tumor types were collected. All data were based on clinical feature, MRI, and follow-up. Results: Among the 21 cases, gross total resection of tumor was achieved in 7 of all patients, subtotal in 11, and partial in 3. No intracranial hemorrhage or death occurred postoperatively. Postoperative infectionoccurred in one patient and cerebrospinal fluid leakage occurred in 3 patients. Four patients recovered after treatment. Conclusion: According to the clinical feature and MRI, it is safe and effective to choose the transcranial surgery and then transsphenoidal surgery for specific giant pituitary adenomas, which can improve treatment effects and reduce postoperative complications.

An Empirical Calibration of the Mixing-Length Parameter α

NASA Astrophysics Data System (ADS)

Ferraro, Francesco R.; Valenti, Elena; Straniero, Oscar; Origlia, Livia

2006-05-01

We present an empirical calibration of the mixing-length free parameter α based on a homogeneous infrared database of 28 Galactic globular clusters spanning a wide metallicity range (-2.15<[Fe/H]<-0.2). Empirical estimates of the red giant effective temperatures have been obtained from infrared colors. Suitable relations linking these temperatures to the cluster metallicity have been obtained and compared to theoretical predictions. An appropriate set of models for the Sun and Population II giants has been computed by using both the standard solar metallicity (Z/X)solar=0.0275 and the most recently proposed value (Z/X)solar=0.0177. We find that when the standard solar metallicity is adopted, a unique value of α=2.17 can be used to reproduce both the solar radius and the Population II red giant temperature. Conversely, when the new solar metallicity is adopted, two different values of α are required: α=1.86 to fit the solar radius and α~2.0 to fit the red giant temperatures. However, it must be noted that regardless the adopted solar reference, the α-parameter does not show any significant dependence on metallicity. Based on observations collected at the European Southern Observatory (ESO), La Silla, Chile. Also based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundacion Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

The remarkable 2011 outburst of the magnetar Swift J1822.3-1606

NASA Astrophysics Data System (ADS)

Chakraborty, Manoneeta; Gogus, Ersin

2016-07-01

Energetic bursts in the X-ray/soft gamma ray band are often observed from magnetars (magnetic field in the range 10^{14} - 10^{15} G). The most energetic of these bursts,- the giant flares, have been observed only from a few sources and exhibit distinct observational characteristics. The 2011 outburst of the relatively low magnetic field magnetar Swift J1822.3-1606 was quite extraordinary due to the interesting timing features observed during this outburst. Periodic modulations at the pulsar spin period were clearly visible, which is a characteristic typical feature seen during the decaying tail of magnetar giant flares. We investigated the temporal variations of the X-ray emission during the early phases of this outburst. The hardness ratio (HR) was found to be strongly anti-correlated X-ray pulse profile intensity much alike that is observed in the case of giant flares. The evolution of the pulse profile morphology also showed a similar behaviour like that for the giant flares but on much longer time scales. The energy released during the entire outburst is comparable to the energy emitted in minutes during the decaying tail of the giant flares. Based on these similarities, we suggest that the same underlying mechanism is probably triggering both the outburst and the giant flares. We propose that the trapped fireball that develops in the magnetosphere at the onset of such energetic events, can radiate away efficiently in minutes in the case of the giant flares, whereas for Swift J1822.3-1606, the efficiency of radiation of the fireball is not as high and, therefore, lasts much longer displaying an outburst. Such a scenario is well supported by the existing theoretical models of magnetars.

The Bamboo-Eating Giant Panda Harbors a Carnivore-Like Gut Microbiota, with Excessive Seasonal Variations

PubMed Central

Xue, Zhengsheng; Zhang, Wenping; Wang, Linghua; Hou, Rong; Zhang, Menghui; Fei, Lisong; Zhang, Xiaojun; Huang, He; Bridgewater, Laura C.; Jiang, Yi; Jiang, Chenglin; Zhao, Liping

2015-01-01

ABSTRACT The giant panda evolved from omnivorous bears. It lives on a bamboo-dominated diet at present, but it still retains a typical carnivorous digestive system and is genetically deficient in cellulose-digesting enzymes. To find out whether this endangered mammalian species, like other herbivores, has successfully developed a gut microbiota adapted to its fiber-rich diet, we conducted a 16S rRNA gene-based large-scale structural profiling of the giant panda fecal microbiota. Forty-five captive individuals were sampled in spring, summer, and late autumn within 1 year. Significant intraindividual variations in the diversity and structure of gut microbiota across seasons were observed in this population, which were even greater than the variations between individuals. Compared with published data sets involving 124 gut microbiota profiles from 54 mammalian species, these giant pandas, together with 9 captive and 7 wild individuals investigated previously, showed extremely low gut microbiota diversity and an overall structure that diverged from those of nonpanda herbivores but converged with those of carnivorous and omnivorous bears. The giant panda did not harbor putative cellulose-degrading phylotypes such as Ruminococcaceae and Bacteroides bacteria that are typically enriched in other herbivores, but instead, its microbiota was dominated by Escherichia/Shigella and Streptococcus bacteria. Members of the class Clostridia were common and abundant in the giant panda gut microbiota, but most of the members present were absent in other herbivores and were not phylogenetically related with known cellulolytic lineages. Therefore, the giant panda appears not to have evolved a gut microbiota compatible with its newly adopted diet, which may adversely influence the coevolutionary fitness of this herbivore. PMID:25991678

Magnetic fields in single late-type giants in the Solar vicinity: How common is magnetic activity on the giant branches?

NASA Astrophysics Data System (ADS)

Konstantinova-Antova, Renada; Aurière, Michel; Charbonnel, Corinne; Drake, Natalia; Wade, Gregg; Tsvetkova, Svetla; Petit, Pascal; Schröder, Klaus-Peter; Lèbre, Agnes

2014-08-01

We present our first results on a new sample containing all single G, K and M giants down to V = 4 mag in the Solar vicinity, suitable for spectropolarimetric (Stokes V) observations with Narval at TBL, France. For detection and measurement of the magnetic field (MF), the Least Squares Deconvolution (LSD) method was applied (Donati et al. 1997) that in the present case enables detection of large-scale MFs even weaker than the solar one (the typical precision of our longitudinal MF measurements is 0.1-0.2 G). The evolutionary status of the stars is determined on the basis of the evolutionary models with rotation (Lagarde et al. 2012; Charbonnel et al., in prep.) and fundamental parameters given by Massarotti et al. (1998). The stars appear to be in the mass range 1-4 M ⊙, situated at different evolutionary stages after the Main Sequence (MS), up to the Asymptotic Giant Branch (AGB). The sample contains 45 stars. Up to now, 29 stars are observed (that is about 64% of the sample), each observed at least twice. For 2 stars in the Hertzsprung gap, one is definitely Zeeman detected. Only 5 G and K giants, situated mainly at the base of the Red Giant Branch (RGB) and in the He-burning phase are detected. Surprisingly, a lot of stars ascending towards the RGB tip and in early AGB phase are detected (8 of 13 observed stars). For all Zeeman detected stars v sin i is redetermined and appears in the interval 2-3 km/s, but few giants with MF possess larger v sin i.

Ghost of habitat past: historic habitat affects the contemporary distribution of giant garter snakes in a modified landscape.

USGS Publications Warehouse

Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

2014-01-01

Historic habitat conditions can affect contemporary communities and populations, but most studies of historic habitat are based on the reduction in habitat extent or connectivity. Little is known about the effects of historic habitat on contemporary species distributions when historic habitat has been nearly completely removed, but species persist in a highly altered landscape. More than 93% of the historic wetlands in the Central Valley of California, USA, have been drained and converted to agricultural and other uses, but agricultural wetlands, such as rice and its supporting infrastructure of canals, allow some species to persist. Little is known about the distribution of giant garter snakes Thamnophis gigas, a rare aquatic snake species inhabiting this predominantly agricultural landscape, or the variables that affect where this species occurs. We used occupancy modeling to examine the distribution of giant garter snakes at the landscape scale in the Sacramento Valley (northern portion of the Central Valley) of California, with an emphasis on the relative strength of historic and contemporary variables (landscape-scale habitat, local microhabitat, vegetation composition and relative prey counts) for predicting giant garter snake occurrence. Proximity to historic marsh best explained variation in the probability of occurrence of giant garter snakes at the landscape scale, with greater probability of occurrence near historic marsh. We suspect that the importance of distance to historic marsh represents dispersal limitations of giant garter snakes. These results suggest that preserving and restoring areas near historic marsh, and minimizing activities that reduce the extent of marsh or marsh-like (e.g. rice agriculture, canal) habitats near historic marsh may be advantageous to giant garter snakes.

Expression of CD34 and CD68 in peripheral giant cell granuloma and central giant cell granuloma: An immunohistochemical analysis.

PubMed

Vk, Varsha; Hallikeri, Kaveri; Girish, H C; Murgod, Sanjay

2014-01-01

Central and Peripheral giant cell granulomas of jaws are uncommon, benign, reactive disorders that are characterized by the presence of numerous multinucleated giant cells and mononuclear cells within a stroma. The origin of the multinucleated giant cells is controversial; probably originating from fusion of histiocytes, endothelial cells and fibroblasts. To assess the expression of CD34 and CD68 in central and peripheral giant cell granulomas to understand the origin of these multinucleated giant cells. Twenty cases of Central and Peripheral giant cell granulomas were evaluated immunohistochemically for CD34 and CD68 proteins expression. Immunopositivity for CD34 was seen only in cytoplasm of endothelial cells of blood vessels; whereas, consistent cytoplasmic immunopositivity for CD68 was seen in few stromal cells. Statistical significance was seen in mean number of multinucleated giant cells, mean number of nuclei in multinucleated giant cells, CD68 expression and ratio of macrophages to multinucleated giant cells among two lesions. Although the central giant cell granulomas share some clinical and histopathological similarities with peripheral giant cell granulomas, differences in mean number of nuclei in multinucleated giant cells and CD68 immunoreactivity may underlie the distinct clinical behavior.

Analysis of Antibacterial Activity and Bioactive Compounds of the Giant Mushroom, Macrocybe gigantea (Agaricomycetes), from India.

PubMed

Gaur, Tanvi; Rao, P B

2017-01-01

The antibacterial activity, phenolic profile, and bioactive compounds of fruiting bodies from 2 strains (MA1 and MA2) of the giant mushroom Macrocybe gigantea were evaluated to access their nutraceutical efficacy. The antibacterial activity was higher in MA2 against all selected pathogenic bacteria. Selected phenolics were analyzed by high-performance liquid chromatography coupled with ultraviolet-visible detection. Gallic acid, ferulic acid, quercetin, p-hydroxy benzoic acid, cinnamic acid, and rutin contents (micrograms per gram dry weight) were quantified. Quercetin and rutin were absent in both strains of M. gigantea. M. gigantea MA2 showed relatively higher phenolic content (915.8 μg/g dry weight) than M. gigantea MA1 (854.4 μg/g dry weight). Among the phenolics, gallic acid is found in the largest amount; in M. gigantea MA2, it was 847.9 ± 2.67 μg/g dry weight. Gas chromatography-mass spectrometry analysis showed the presence of bioactive compounds in both strains; most compounds were antibacterial. Thus, the selected strains of M. gigantea can combat oxidative damage and can be used in foods, pharmaceuticals, and cosmetics because of their antioxidant potential.

A proposed integrated approach for the preclinical evaluation of phage therapy in Pseudomonas infections

NASA Astrophysics Data System (ADS)

Danis-Wlodarczyk, Katarzyna; Vandenheuvel, Dieter; Jang, Ho Bin; Briers, Yves; Olszak, Tomasz; Arabski, Michal; Wasik, Slawomir; Drabik, Marcin; Higgins, Gerard; Tyrrell, Jean; Harvey, Brian J.; Noben, Jean-Paul; Lavigne, Rob; Drulis-Kawa, Zuzanna

2016-06-01

Bacteriophage therapy is currently resurging as a potential complement/alternative to antibiotic treatment. However, preclinical evaluation lacks streamlined approaches. We here focus on preclinical approaches which have been implemented to assess bacteriophage efficacy against Pseudomonas biofilms and infections. Laser interferometry and profilometry were applied to measure biofilm matrix permeability and surface geometry changes, respectively. These biophysical approaches were combined with an advanced Airway Surface Liquid infection model, which mimics in vitro the normal and CF lung environments, and an in vivo Galleria larvae model. These assays have been implemented to analyze KTN4 (279,593 bp dsDNA genome), a type-IV pili dependent, giant phage resembling phiKZ. Upon contact, KTN4 immediately disrupts the P. aeruginosa PAO1 biofilm and reduces pyocyanin and siderophore production. The gentamicin exclusion assay on NuLi-1 and CuFi-1 cell lines revealed the decrease of extracellular bacterial load between 4 and 7 logs and successfully prevents wild-type Pseudomonas internalization into CF epithelial cells. These properties and the significant rescue of Galleria larvae indicate that giant KTN4 phage is a suitable candidate for in vivo phage therapy evaluation for lung infection applications.

Ten-Year Experience of Managing Giant Duodenal Ulcer Perforations with Triple Tube Ostomy at Tertiary Hospital of North India.

PubMed

Ali, Wasif Mohammad; Ansari, M M; Rizvi, Syed Amjad Ali; Rabb, A Z; Mansoor, Tariq; Harris, Syed Hassan; Akhtar, Mohd Sadiq

2018-02-01

Duodenal ulcer perforations have been known since 1600 AD. It is a common surgical emergency and every surgeon will encounter it. The perforation size of >2 cm has been used as the criteria for defining Giant duodenal ulcers. The management of giant duodenal perforations in hemodynamically unstable patient with comorbid condition is taxing because of high incidence of the postoperative leak and mortality. We have used the simple technique of Triple Tube Ostomy after the primary closure of the defect with encouraging results. It is a retrospective study done at the J. N medical college AMU Aligarh from May 2005 to May 2015. Hemodynamically unstable patients who have presented to the emergency with preoperative diagnoses of giant duodenal ulcer perforation and had undergone triple tube ostomy with primary repair of the perforation were included in the study. There were 34 patients of giant duodenal perforation who presented in shock. All of them underwent triple-tube-ostomy after primary repair of the duodenum. Thirty-two patients recovered with two mortalities (5.8 %). Several definite surgical techniques have been described for the management of giant duodenal ulcer perforation but they are complex, have very high morbidity and mortality rate and require an expert surgeon. A close retrospective scrutiny of the patients suggests that simple triple-tube-ostomy technique which is based on the principle of damage control surgery has good postoperative results Therefore, we recommend it as the procedure of choice in these patients.

Tharsis Formation by Chemical Plume Due to Giant Impact Event

NASA Astrophysics Data System (ADS)

Fleck, J.; Weeraratne, D. S.; Olson, P.

2014-12-01

Tharsis formed early in the history of Mars, likely during the Noachian but later than the hemispheric crustal dichotomy that it partially overprints (Johnson and Phillips, 2005; Solomon et al., 2005; Wenzel et al., 2004). It has been suggested that the crustal dichotomy may have been formed by a giant impact (Andrews-Hanna et al., 2008; Marinova et al., 2008; Nimmo et al., 2008). Several models have been proposed to explain a localized orogeny, but predict multiple, evenly-spaced plumes or have instability growth and rise times which are longer than Tharsis formation. We use fluid dynamic experiments to model the differentiation process during Mars accretion using low viscosity glucose syrup solutions and an emulsion of liquid gallium for the metal-rich magma ocean and a high viscosity glucose syrup for the mantle. Our experiments demonstrate the formation of metal-silicate diapirs from metal emulsion drops that form a pond at the base of the magma ocean. The diapirs descend through the underlying mantle with trailing conduit of low viscosity silicate material. The silicate material is buoyant and eventually ascends back through the conduit. Remaining emulsion drops that do not adhere with the diapir fall through the conduit, forcing the buoyant molten silicate material to exit the conduit laterally and ascend along a new trajectory. The time elapsed between diapir formation and ascent of the chemical plume in experiments scales with the time between the formation of the crustal dichotomy on Mars and the formation of Tharsis. Our model offers an explanation for the rapid formation of Tharsis on the edge of the crustal dichotomy via a single large upwelling event followed by smaller upwellings producing and the late stages of effusive volcanism observed in the Tharsis region.

Viscosity and Structure of a Late Lunar Magma Ocean Liquid: Implications for the Purity of Ferroan Anorthosites and the Dynamics of a Crystallizing Magma Ocean

NASA Astrophysics Data System (ADS)

Dygert, N. J.; Lin, J. F.; Marshall, E. W., IV; Kono, Y.; Gardner, J. E.

2016-12-01

The current paradigm argues the Moon formed after a giant impact that produced a deep lunar magma ocean (LMO). After a period of turbulent convection, the LMO experienced fractional crystallization, causing the initially peridotitic liquid to evolve to a plagioclase-saturated ferrobasalt. The lunar crust, much of which comprises 93-98% pure anorthosite [1,2], formed by flotation of positively buoyant plagioclase on the residual liquid. A flotation crust would contain some trapped melt; compaction of the melt out of the crust before solidification may be necessary to generate a very pure anorthitic crust. The efficiency of this process depends on the previously unmeasured viscosity of the residual liquid [3]. To characterize the viscosity and thermal equation of state of a late LMO liquid, we conducted experiments at the Advanced Photon Source, Beamline 16-BM-B, Argonne National Laboratory on a nominally anhydrous Ti-rich ferrobasalt [4]. X-ray radiography and diffuse scattering experiments were conducted in a Paris-Edinburgh apparatus in graphite-lined BN capsules, allowing in-situ observation of viscosity and derivation of thermal EoS at P-T conditions relevant to the Moon (1300-1600°C, 0.1-4.4GPa). We calculated viscosities of 0.23-1.45 Pa·s for the melt; based on 11 observations, we find that viscosity is pressure insensitive under the conditions explored. Viscosity can be modeled by an Arrhenius relation with an activation enthalpy of 66 kJ/mol. Composition-dependent predictive models [5] overestimate our observations by roughly a factor of 2. Preliminary analysis suggests no pressure-dependent structural transition over the conditions explored. Late LMO liquids brought to the lunar core-mantle boundary by cumulate mantle overturn may be positively buoyant, implying the seismically attenuating layer around the lunar core contains a denser, higher-Ti melt. Our results suggest that efficient phase segregation in the lunar magma ocean and compaction in the anorthositic flotation crust can produce a high-purity crust under physically reasonable conditions. [1] Warren (1990), AmMin 75, 46-58. [2] Ohtake et al. (2009), Nature 461, 236-240. [3] Piskorz, & Stevenson (2014), Icarus 239, 238-243. [4] Longhi (2003), JGR 108, doi:10.1029/2002JE001941. [5] Giordano et al. (2008), EPSL 271, 123-134.

The Pan-Pacific Planet Search. IV. Two Super-Jupiters in a 3:5 Resonance Orbiting the Giant Star HD 33844

NASA Astrophysics Data System (ADS)

Wittenmyer, Robert A.; Johnson, John Asher; Butler, R. P.; Horner, Jonathan; Wang, Liang; Robertson, Paul; Jones, M. I.; Jenkins, J. S.; Brahm, R.; Tinney, C. G.; Mengel, M. W.; Clark, J.

2016-02-01

We report the discovery of two giant planets orbiting the K giant HD 33844 based on radial velocity data from three independent campaigns. The planets move on nearly circular orbits with semimajor axes {a}b\\=1.60+/- 0.02 AU and {a}c=2.24+/- 0.05 AU, and have minimum masses (m sin I) of {M}b=1.96+/- 0.12 {M}{{Jup}} and {M}c=1.76+/- 0.18 {M}{{Jup}}. Detailed N-body dynamical simulations show that the two planets have remained on stable orbits for more than 106 years for low eccentricities and are most likely trapped in a mutual 3:5 mean motion resonance.

DISCOVERY OF A RED GIANT WITH SOLAR-LIKE OSCILLATIONS IN AN ECLIPSING BINARY SYSTEM FROM KEPLER SPACE-BASED PHOTOMETRY

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

Hekker, S.; Debosscher, J.; De Ridder, J.

2010-04-20

Oscillating stars in binary systems are among the most interesting stellar laboratories, as these can provide information on the stellar parameters and stellar internal structures. Here we present a red giant with solar-like oscillations in an eclipsing binary observed with the NASA Kepler satellite. We compute stellar parameters of the red giant from spectra and the asteroseismic mass and radius from the oscillations. Although only one eclipse has been observed so far, we can already determine that the secondary is a main-sequence F star in an eccentric orbit with a semi-major axis larger than 0.5 AU and orbital period longermore » than 75 days.« less

Organic matter in meteorites and comets - Possible origins

NASA Technical Reports Server (NTRS)

Anders, Edward

1991-01-01

At least six extraterrestrial environments may have contributed organic compounds to meteorites and comets: solar nebula, giant-planet subnebulae, asteroid interiors containing liquid water, carbon star atmospheres, and diffuse or dark interstellar clouds. The record in meteorites is partly obscured by pervasive reheating that transformed much of the organic matter to kerogen; nonetheless, it seems that all six formation sites contributed. For comets, the large abundance of HCHO, HCN, and unsaturated hydrocarbons suggests an interstellar component of 50 percent or more, but the contributions of various interstellar processes, and of a solar-nebula component, are hard to quantify. A research program is outlined that may help reduce these uncertainties.

Moist, Double-diffusive convection

NASA Astrophysics Data System (ADS)

Oishi, Jeffrey; Burns, Keaton; Brown, Ben; Lecoanet, Daniel; Vasil, Geoffrey

2017-11-01

Double-diffusive convection occurs when the competition between stabilizing and a destabilizing buoyancy source is mediated by a difference in the diffusivity of each source. Such convection is important in a wide variety of astrophysical and geophysical flows. However, in giant planets, double-diffusive convection occurs in regions where condensation of important components of the atmosphere occurs. Here, we present preliminary calculations of moist, double-diffusive convection using the Dedalus pseudospectral framework. Using a simple model for phase change, we verify growth rates for moist double diffusive convection from linear calculations and report on preliminary relationships between the ability to form liquid phase and the resulting Nusselt number in nonlinear simulations.

Enhancement of the giant magnetoresistance in spin valves via oxides formed from magnetic layers

NASA Astrophysics Data System (ADS)

Gillies, M. F.; Kuiper, A. E. T.

2000-11-01

An enhancement of the giant magnetoresistance effect is investigated in spin valves where oxide layers, which are formed from magnetic layers, are incorporated in the structure. Information about Co-Fe based nanooxide layer (NOL) is obtained via x-ray photoelectron spectroscopy and Rutherford backscattering spectrometry. Cross-section transmission electron microscopy is also used to explore the effect of an NOL on the polycrystalline structure of the spin valve.

Occurrence and use of an estuarine habitat by giant manta ray Manta birostris.

PubMed

Medeiros, A M; Luiz, O J; Domit, C

2015-06-01

Based on the knowledge of local artisanal fishermen and on direct observations, this study presents evidence that the giant manta ray Manta birostris uses the Paranaguá estuarine complex in south Brazil, south-western Atlantic Ocean, in a predictable seasonal pattern. Behavioural observations suggest that the estuary can act as a nursery ground for M. birostris during the summer. © 2015 The Fisheries Society of the British Isles.

Expression of CD34 and CD68 in peripheral giant cell granuloma and central giant cell granuloma: An immunohistochemical analysis

PubMed Central

VK, Varsha; Hallikeri, Kaveri; Girish, HC; Murgod, Sanjay

2014-01-01

Background: Central and Peripheral giant cell granulomas of jaws are uncommon, benign, reactive disorders that are characterized by the presence of numerous multinucleated giant cells and mononuclear cells within a stroma. The origin of the multinucleated giant cells is controversial; probably originating from fusion of histiocytes, endothelial cells and fibroblasts. Objective: To assess the expression of CD34 and CD68 in central and peripheral giant cell granulomas to understand the origin of these multinucleated giant cells. Materials and Methods: Twenty cases of Central and Peripheral giant cell granulomas were evaluated immunohistochemically for CD34 and CD68 proteins expression. Results: Immunopositivity for CD34 was seen only in cytoplasm of endothelial cells of blood vessels; whereas, consistent cytoplasmic immunopositivity for CD68 was seen in few stromal cells. Statistical significance was seen in mean number of multinucleated giant cells, mean number of nuclei in multinucleated giant cells, CD68 expression and ratio of macrophages to multinucleated giant cells among two lesions. Conclusion: Although the central giant cell granulomas share some clinical and histopathological similarities with peripheral giant cell granulomas, differences in mean number of nuclei in multinucleated giant cells and CD68 immunoreactivity may underlie the distinct clinical behavior. PMID:25948986

Habitable moons around extrasolar giant planets

NASA Technical Reports Server (NTRS)

Williams, D. M.; Kasting, J. F.; Wade, R. A.

1997-01-01

Possible planetary objects have now been discovered orbiting nine different main-sequence stars. These companion objects (some of which might actually be brown dwarfs) all have a mass at least half that of Jupiter, and are therefore unlikely to be hospitable to Earth-like life: jovian planets and brown dwarfs support neither a solid nor a liquid surface near which organisms might dwell. Here we argue that rocky moons orbiting these companions could be habitable if the planet-moon system orbits the parent star within the so-called 'habitable zone', where life-supporting liquid water could be present. The companions to the stars 16 Cygni B and 47 Ursae Majoris might satisfy this criterion. Such a moon would, however, need to be large enough (>0.12 Earth masses) to retain a substantial and long-lived atmosphere, and would also need to possess a strong magnetic field in order to prevent its atmosphere from being sputtered away by the constant bombardment of energetic ions from the planet's magnetosphere.

Habitable moons around extrasolar giant planets.

PubMed

Williams, D M; Kasting, J F; Wade, R A

1997-01-16

Possible planetary objects have now been discovered orbiting nine different main-sequence stars. These companion objects (some of which might actually be brown dwarfs) all have a mass at least half that of Jupiter, and are therefore unlikely to be hospitable to Earth-like life: jovian planets and brown dwarfs support neither a solid nor a liquid surface near which organisms might dwell. Here we argue that rocky moons orbiting these companions could be habitable if the planet-moon system orbits the parent star within the so-called 'habitable zone', where life-supporting liquid water could be present. The companions to the stars 16 Cygni B and 47 Ursae Majoris might satisfy this criterion. Such a moon would, however, need to be large enough (>0.12 Earth masses) to retain a substantial and long-lived atmosphere, and would also need to possess a strong magnetic field in order to prevent its atmosphere from being sputtered away by the constant bombardment of energetic ions from the planet's magnetosphere.

Giant and switchable surface activity of liquid metal via surface oxidation

PubMed Central

Khan, Mohammad Rashed; Eaker, Collin B.; Bowden, Edmond F.; Dickey, Michael D.

2014-01-01

We present a method to control the interfacial tension of a liquid alloy of gallium via electrochemical deposition (or removal) of the oxide layer on its surface. In sharp contrast with conventional surfactants, this method provides unprecedented lowering of surface tension (∼500 mJ/m2 to near zero) using very low voltage, and the change is completely reversible. This dramatic change in the interfacial tension enables a variety of electrohydrodynamic phenomena. The ability to manipulate the interfacial properties of the metal promises rich opportunities in shape-reconfigurable metallic components in electronic, electromagnetic, and microfluidic devices without the use of toxic mercury. This work suggests that the wetting properties of surface oxides—which are ubiquitous on most metals and semiconductors—are intrinsic “surfactants.” The inherent asymmetric nature of the surface coupled with the ability to actively manipulate its energetics is expected to have important applications in electrohydrodynamics, composites, and melt processing of oxide-forming materials. PMID:25228767

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. VI. HD 238914 and TYC 3318-01333-1: two more Li-rich giants with planets

NASA Astrophysics Data System (ADS)

Adamów, M.; Niedzielski, A.; Kowalik, K.; Villaver, E.; Wolszczan, A.; Maciejewski, G.; Gromadzki, M.

2018-05-01

Context. We present the latest results of our search for planets with HARPS-N at the 3.6 m Telescopio Nazionale Galileo under the Tracking Advanced Planetary Systems project: an in-depth study of the 15 most Li abundant giants from the PennState - Toruń Planet Search sample. Aims: Our goals are first, to obtain radial velocities of the most Li-rich giants we identified in our sample to search for possible low-mass substellar companions, and second, to perform an extended spectral analysis to define the evolutionary status of these stars. Methods: This work is based on high-resolution spectra obtained with the Hobby-Eberly Telescope and its High Resolution Spectrograph, and with the HARPS-N spectrograph at the Telescopio Nazionale Galileo. Two stars, HD 181368 and HD 188214, were also observed with UVES at the VLT to determine beryllium abundances. Results: We report i) the discovery of two new planetary systems around the Li-rich giant stars: HD 238914 and TYC 3318-01333-1 (a binary system); ii) reveal a binary Li-rich giant, HD 181368; iii) although our current phase coverage is not complete, we suggest the presence of planetary mass companions around TYC 3663-01966-1 and TYC 3105-00152-1; iv) we confirm the previous result for BD+48 740 and present updated orbital parameters, and v) we find a lack of a relation between the Li enhancement and the Be abundance for the stars HD 181368 and HD 188214, for which we acquired blue spectra. Conclusions: We found seven stars with stellar or potential planetary companions among the 15 Li-rich giant stars. The binary star frequency of the Li-rich giants in our sample appears to be normal, but the planet frequency is twice that of the general sample, which suggests a possible connection between hosting a companion and enhanced Li abundance in giant stars. We also found most of the companions orbits to be highly eccentric. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de CanariasRV data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/613/A47

Convective-core Overshoot and Suppression of Oscillations: Constraints from Red Giants in NGC 6811

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

Arentoft, T.; Brogaard, K.; Jessen-Hansen, J.

Using data from the NASA spacecraft Kepler , we study solar-like oscillations in red giant stars in the open cluster NGC 6811. We determine oscillation frequencies, frequency separations, period spacings of mixed modes, and mode visibilities for eight cluster giants. The oscillation parameters show that these stars are helium-core-burning red giants. The eight stars form two groups with very different oscillation power spectra; the four stars with the lowest Δ ν values display rich sets of mixed l = 1 modes, while this is not the case for the four stars with higher Δ ν . For the four starsmore » with lowest Δ ν , we determine the asymptotic period spacing of the mixed modes, Δ P , which together with the masses we derive for all eight stars suggest that they belong to the so-called secondary clump. Based on the global oscillation parameters, we present initial theoretical stellar modeling that indicates that we can constrain convective-core overshoot on the main sequence and in the helium-burning phase for these ∼2 M {sub ⊙} stars. Finally, our results indicate less mode suppression than predicted by recent theories for magnetic suppression of certain oscillation modes in red giants.« less

New and updated stellar parameters for 71 evolved planet hosts. On the metallicity-giant planet connection

NASA Astrophysics Data System (ADS)

Mortier, A.; Santos, N. C.; Sousa, S. G.; Adibekyan, V. Zh.; Delgado Mena, E.; Tsantaki, M.; Israelian, G.; Mayor, M.

2013-09-01

Context. It is still being debated whether the well-known metallicity-giant planet correlation for dwarf stars is also valid for giant stars. For this reason, having precise metallicities is very important. Precise stellar parameters are also crucial to planetary research for several other reasons. Different methods can provide different results that lead to discrepancies in the analysis of planet hosts. Aims: To study the impact of different analyses on the metallicity scale for evolved stars, we compare different iron line lists to use in the atmospheric parameter derivation of evolved stars. Therefore, we use a sample of 71 evolved stars with planets. With these new homogeneous parameters, we revisit the metallicity-giant planet connection for evolved stars. Methods: A spectroscopic analysis based on Kurucz models in local thermodynamic equilibrium (LTE) was performed through the MOOG code to derive the atmospheric parameters. Two different iron line list sets were used, one built for cool FGK stars in general, and the other for giant FGK stars. Masses were calculated through isochrone fitting, using the Padova models. Kolmogorov-Smirnov tests (K-S tests) were then performed on the metallicity distributions of various different samples of evolved stars and red giants. Results: All parameters compare well using a line list set, designed specifically for cool and solar-like stars to provide more accurate temperatures. All parameters derived with this line list set are preferred and are thus adopted for future analysis. We find that evolved planet hosts are more metal-poor than dwarf stars with giant planets. However, a bias in giant stellar samples that are searched for planets is present. Because of a colour cut-off, metal-rich low-gravity stars are left out of the samples, making it hard to compare dwarf stars with giant stars. Furthermore, no metallicity enhancement is found for red giants with planets (log g < 3.0 dex) with respect to red giants without planets. The data presented here are based on observations collected at the La Silla Paranal Observatory, ESO (Chile) with the FEROS spectrograph at the 2.2 m telescope (ESO runs ID 70.C-0084, 088.C-0892, 089.C-0444, and 090.C-0146) and the HARPS spectrograph at the 3.6 m telescope (ESO run ID 72.C-0488); at the Paranal Observatory, ESO (Chile) with the UVES spectrograph at the VLT Kueyen telescope (ESO runs ID 074.C-0134, 079.C-0131, 380.C-0083, and 083.C-0174); at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with the FIES spectrograph at the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden (program ID 44-210); and at the Observatoire de Haute-Provence (OHP, CNRS/OAMP), France with the SOPHIE spectrographs at the 1.93 m telescope (program ID 11B.DISC.SOUS).Tables 1, 5, 6 and Appendix A are available in electronic form at http://www.aanda.orgTables 5, 6, and A.1 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/557/A70

Characterizing Cold Giant Planets in Reflected Light: Lessons from 50 Years of Outer Solar System Exploration and Observation

NASA Technical Reports Server (NTRS)

Marley, Mark Scott; Hammel, Heidi

2014-01-01

A space based coronagraph, whether as part of the WFIRST/AFTA mission or on a dedicated space telescope such as Exo-C or -S, will be able to obtain photometry and spectra of multiple gas giant planets around nearby stars, including many known from radial velocity detections. Such observations will constrain the masses, atmospheric compositions, clouds, and photochemistry of these worlds. Giant planet albedo models, such as those of Cahoy et al. (2010) and Lewis et al. (this meeting), will be crucial for mission planning and interpreting the data. However it is equally important that insights gleaned from decades of solar system imaging and spectroscopy of giant planets be leveraged to optimize both instrument design and data interpretation. To illustrate these points we will draw on examples from solar system observations, by both HST and ground based telescopes, as well as by Voyager, Galileo, and Cassini, to demonstrate the importance clouds, photochemical hazes, and various molecular absorbers play in sculpting the light scattered by solar system giant planets. We will demonstrate how measurements of the relative depths of multiple methane absorption bands of varying strengths have been key to disentangling the competing effects of gas column abundances, variations in cloud height and opacity, and scattering by high altitude photochemical hazes. We will highlight both the successes, such as the accurate remote determination of the atmospheric methane abundance of Jupiter, and a few failures from these types of observations. These lessons provide insights into technical issues facing spacecraft designers, from the selection of the most valuable camera filters to carry to the required capabilities of the flight spectrometer, as well as mission design questions such as choosing the most favorable phase angles for atmospheric characterization.

MIGRATION AND GROWTH OF PROTOPLANETARY EMBRYOS. II. EMERGENCE OF PROTO-GAS-GIANT CORES VERSUS SUPER EARTH PROGENITORS

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

Liu, Beibei; Zhang, Xiaojia; Lin, Douglas N. C.

2015-01-01

Nearly 15%-20% of solar type stars contain one or more gas giant planets. According to the core-accretion scenario, the acquisition of their gaseous envelope must be preceded by the formation of super-critical cores with masses 10 times or larger than that of the Earth. It is natural to link the formation probability of gas giant planets with the supply of gases and solids in their natal disks. However, a much richer population of super Earths suggests that (1) there is no shortage of planetary building block material, (2) a gas giant's growth barrier is probably associated with whether it can mergemore » into super-critical cores, and (3) super Earths are probably failed cores that did not attain sufficient mass to initiate efficient accretion of gas before it is severely depleted. Here we construct a model based on the hypothesis that protoplanetary embryos migrated extensively before they were assembled into bona fide planets. We construct a Hermite-Embryo code based on a unified viscous-irradiation disk model and a prescription for the embryo-disk tidal interaction. This code is used to simulate the convergent migration of embryos, and their close encounters and coagulation. Around the progenitors of solar-type stars, the progenitor super-critical-mass cores of gas giant planets primarily form in protostellar disks with relatively high (≳ 10{sup –7} M {sub ☉} yr{sup –1}) mass accretion rates, whereas systems of super Earths (failed cores) are more likely to emerge out of natal disks with modest mass accretion rates, due to the mean motion resonance barrier and retention efficiency.« less

Underground neutrino detectors for particle and astroparticle Science: The Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER)

NASA Astrophysics Data System (ADS)

Rubbia, André

2009-06-01

The current focus of the CERN program is the Large Hadron Collider (LHC), however, CERN is engaged in long baseline neutrino physics with the CNGS project and supports T2K as recognized CERN RE13, and for good reasons: a number of observed phenomena in high-energy physics and cosmology lack their resolution within the Standard Model of particle physics; these puzzles include the origin of neutrino masses, CP-violation in the leptonic sector, and baryon asymmetry of the Universe. They will only partially be addressed at LHC. A positive measurement of sin2 2θ13 > 0.01 would certainly give a tremendous boost to neutrino physics by opening the possibility to study CP violation in the lepton sector and the determination of the neutrino mass hierarchy with upgraded conventional super-beams. These experiments (so called 'Phase II') require, in addition to an upgraded beam power, next generation very massive neutrino detectors with excellent energy resolution and high detection efficiency in a wide neutrino energy range, to cover 1st and 2nd oscillation maxima, and excellent particle identification and p0 background suppression. Two generations of large water Cherenkov detectors at Kamioka (Kamiokande and Super-Kamiokande) have been extremely successful. And there are good reasons to consider a third generation water Cherenkov detector with an order of magnitude larger mass than Super-Kamiokande for both non-accelerator (proton decay, supernovae,...) and accelerator-based physics. On the other hand, a very massive underground liquid Argon detector of about 100 kton could represent a credible alternative for the precision measurements of 'Phase II' and aim at significantly new results in neutrino astroparticle and non-accelerator-based particle physics (e.g. proton decay).

The Leo I color-magnitude diagram

NASA Astrophysics Data System (ADS)

Reid, Neill; Mould, Jeremy

1991-04-01

The R-and I-band photometry of the Leo I dwarf galaxy is presented. A relatively narrow giant branch is found, Implying an abundance range of no more than Fe/H/= - 0.7 to - 1.3. This is in contrast to the results is found by Fox and Pritchet (1987) from BV CCD photometry. The distance modulus is estimated as (m - M) = 21.85 + or - 0.15, based on the luminosity of the tip of the red giant branch.

Laboratory study of dense planetary interiors and giant impacts using laser-driven shock waves

NASA Astrophysics Data System (ADS)

Hicks, Damien

2005-10-01

The behavior of matter at Megabar pressures, a few times solid density, and eV temperatures presents a fundamental challenge, one that is critical to our understanding of dense planetary interiors, planetary evolution models, and giant impacts. Under these conditions bulk matter is strongly coupled, with temperatures approaching the Fermi energy and electron wavelengths comparable to the interatomic spacing - a quantum-classical ``transition'' regime not amenable to many of the traditional theoretical approaches used in condensed matter or plasma physics. The laser-driven shock wave has matured into a powerful tool for accessing and probing these conditions with several new techniques having been developed recently. Measurements of the equation-of-state and transport properties of important planetary materials including silica ( SiO2 ) and hydrogen have been performed. In particular, silica - the major constituent of terrestrial planets - has been shown to undergo an insulator-to-conductor transition above melting at conditions similar to those in giant impacts (such as the one believed to have created the Moon) and at the earth's core-mantle boundary. This continuous transformation, occurring at pressures between 1 to ˜4 Mbar, is accompanied by an anomalously high specific heat that returns to the Dulong-Petit value at completion of the transformation. This is suggestive of a ``bond-breaking'' process in the condensed system - analogous to dissociation in a gas - as the fluid transforms from liquid to dense plasma. Work performed in collaboration with T. R. Boehly, P. M. Celliers, J. H. Eggert, J. E. Miller, D. D. Meyerhofer, and G. W. Collins under the auspices of the US DOE by LLNL under Contract No. W-7405-ENG-48 and by the U. Rochester under Cooperative Agreement No. DE-FC03-92SF19460.

The bamboo-eating giant panda harbors a carnivore-like gut microbiota, with excessive seasonal variations.

PubMed

Xue, Zhengsheng; Zhang, Wenping; Wang, Linghua; Hou, Rong; Zhang, Menghui; Fei, Lisong; Zhang, Xiaojun; Huang, He; Bridgewater, Laura C; Jiang, Yi; Jiang, Chenglin; Zhao, Liping; Pang, Xiaoyan; Zhang, Zhihe

2015-05-19

The giant panda evolved from omnivorous bears. It lives on a bamboo-dominated diet at present, but it still retains a typical carnivorous digestive system and is genetically deficient in cellulose-digesting enzymes. To find out whether this endangered mammalian species, like other herbivores, has successfully developed a gut microbiota adapted to its fiber-rich diet, we conducted a 16S rRNA gene-based large-scale structural profiling of the giant panda fecal microbiota. Forty-five captive individuals were sampled in spring, summer, and late autumn within 1 year. Significant intraindividual variations in the diversity and structure of gut microbiota across seasons were observed in this population, which were even greater than the variations between individuals. Compared with published data sets involving 124 gut microbiota profiles from 54 mammalian species, these giant pandas, together with 9 captive and 7 wild individuals investigated previously, showed extremely low gut microbiota diversity and an overall structure that diverged from those of nonpanda herbivores but converged with those of carnivorous and omnivorous bears. The giant panda did not harbor putative cellulose-degrading phylotypes such as Ruminococcaceae and Bacteroides bacteria that are typically enriched in other herbivores, but instead, its microbiota was dominated by Escherichia/Shigella and Streptococcus bacteria. Members of the class Clostridia were common and abundant in the giant panda gut microbiota, but most of the members present were absent in other herbivores and were not phylogenetically related with known cellulolytic lineages. Therefore, the giant panda appears not to have evolved a gut microbiota compatible with its newly adopted diet, which may adversely influence the coevolutionary fitness of this herbivore. The giant panda, an endangered mammalian species endemic to western China, is well known for its unique bamboo diet. Unlike other herbivores that have successfully evolved anatomically specialized digestive systems to efficiently deconstruct fibrous plant matter, the giant panda still retains a gastrointestinal tract typical of carnivores. We characterized the fecal bacterial communities from a giant panda population to determine whether this animal relies on its symbiotic gut microbiota to cope with the complex carbohydrates that dominate its diet, as is common in other herbivores. We found that the giant panda gut microbiota is low in diversity and highly variable across seasons. It also shows an overall composition typical of bears and entirely differentiated from other herbivores, with low levels of putative cellulose-digesting bacteria. The gut microbiota of this herbivore, therefore, may not have well adapted to its highly fibrous diet, suggesting a potential link with its poor digestive efficiency. Copyright © 2015 Xue et al.

Hubble 2020: Outer Planet Atmospheres Legacy (OPAL) Program

NASA Astrophysics Data System (ADS)

Simon, Amy

2017-08-01

Long time base observations of the outer planets are critical in understanding the atmospheric dynamics and evolution of the gas giants. We propose yearly monitoring of each giant planet for the remainder of Hubble's lifetime to provide a lasting legacy of increasingly valuable data for time-domain studies. The Hubble Space Telescope is a unique asset to planetary science, allowing high spatial resolution data with absolute photometric knowledge. For the outer planets, gas/ice giant planets Jupiter, Saturn, Uranus and Neptune, many phenomena happen on timescales of years to decades, and the data we propose are beyond the scope of a typical GO program. Hubble is the only platform that can provide high spatial resolution global studies of cloud coloration, activity, and motion on a consistent time basis to help constrain the underlying mechanics.

The "double panda" sign in Leigh disease.

PubMed

Sonam, Kothari; Bindu, P S; Gayathri, Narayanappa; Khan, Nahid Akhtar; Govindaraju, C; Arvinda, Hanumanthapura R; Nagappa, Madhu; Sinha, Sanjib; Thangaraj, K; Taly, Arun B

2014-07-01

Although the "face of the giant panda" sign on magnetic resonance imaging (MRI) is traditionally considered to be characteristic of Wilson disease, it has also been reported in other metabolic disorders. This study describes the characteristic "giant panda" sign on MRI in a child with Leigh disease. The diagnosis was based on the history of neurological regression; examination findings of oculomotor abnormalities, hypotonia, and dystonia; raised serum lactate levels; and characteristic brain stem and basal ganglia signal changes on MRI. The midbrain and pontine tegmental signal changes were consistent with the "face of the giant panda and her cub" sign. In addition to Wilson disease, metabolic disorders such as Leigh disease should also be considered in the differential diagnosis of this rare imaging finding. © The Author(s) 2013.

A Review of the Low-Frequency Waves in the Giant Magnetospheres

NASA Astrophysics Data System (ADS)

Delamere, P. A.

2016-02-01

The giant magnetospheres harbor a plethora of low-frequency waves with both internal (i.e., moons) and external (i.e., solar wind) source mechanisms. This chapter summarizes the observation of low-frequency waves at Jupiter and Saturn and postulates the underlying physics based on our understanding of magnetodisc generation mechanisms. The source mechanisms of ULF pulsations at the giant magnetospheres are numerous. The satellite-magnetosphere interactions and mass loading of corotational flows generate many low-frequency waves. Observations of low-frequency bursts of radio emissions serve as an excellent diagnostic for understanding satellite-magnetosphere interactions. The outward radial transport of plasma through the magnetodisc and related magnetic flux circulation is a significant source of ULF pulsations; however, it is uncertain how the radial transport mechanism compares with solar wind induced perturbations.

Origin and Diversity of Planetary Systems

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

1997-01-01

Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form around most single stars, although it is possible that most such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Models for the formation of the giant planets found in recent radial velocity searches are discussed.

The International Outer Planets Watch atmospheres node database of giant-planet images

NASA Astrophysics Data System (ADS)

Hueso, R.; Legarreta, J.; Sánchez-Lavega, A.; Rojas, J. F.; Gómez-Forrellad, J. M.

2011-10-01

The Atmospheres Node of the International Outer Planets Watch (IOPW) is aimed to encourage the observations and study of the atmospheres of the Giant Planets. One of its main activities is to provide an interaction between the professional and amateur astronomical communities maintaining an online and fully searchable database of images of the giant planets obtained from amateur astronomers and available to both professional and amateurs [1]. The IOPW database contains about 13,000 image observations of Jupiter and Saturn obtained in the visible range with a few contributions of Uranus and Neptune. We describe the organization and structure of the database as posted in the Internet and in particular the PVOL software (Planetary Virtual Observatory & Laboratory) designed to manage the site and based in concepts from Virtual Observatory projects.

An Extraordinary Outburst of the Magnetar Swift J1822.3-1606

NASA Astrophysics Data System (ADS)

Chakraborty, Manoneeta; Göğüş, Ersin

2015-08-01

The 2011 outburst of Swift J1822.3-1606 was extraordinary; periodic modulations at the spin period of the underlying neutron star were clearly visible, remarkably similar to what is observed during the decaying tail of magnetar giant flares. We investigated the temporal characteristics of X-ray emission during the early phases of the outburst. We performed a periodicity search with the spectral hardness ratio (HR) and found a coherent signal near the spin period of the neutron star, but with a lag of about 3 radians. Therefore, the HR is strongly anti-correlated with the X-ray intensity, which is also seen in the giant flares. We studied the time evolution of the pulse profile and found that it evolves from a complex morphology to a much simpler shape within about a month. Pulse profile simplification also takes place during the giant flares, but on a much shorter timescale of about a few minutes. We found that the amount of energy emitted during the first 25 days of the outburst is comparable to what was detected in minutes during the decaying tail of giant flares. Based on these similarities, we suggest that the triggering mechanisms of the giant flares and the magnetar outbursts are likely the same. We propose that the trapped fireball that develops in the magnetosphere at the onset of the outburst radiates away efficiently in minutes in magnetars exhibiting giant flares, while in other magnetars, such as Swift J1822.3-1606, the efficiency of radiation of the fireball is not as high and, therefore, lasts much longer.

An optical study of X-ray sources in the old open clusters NGC 752 and NGC 6940

NASA Astrophysics Data System (ADS)

van den Berg, M.; Verbunt, F.

2001-08-01

We observed the optical counterparts of X-ray sources in the old open clusters NGC 752 and NGC 6940 to search for the origin of the X-rays. The photometric variability reported earlier for the blue straggler H 209 is not confirmed by our light curves, nor is an indication for variability seen in the spectra; thus its X-rays remain unexplained. The X-rays of VR 111 and VR 114 are likely not a result of magnetic activity as these stars lack strong Ca II H&K emission, while in VR 108 the level of activity could be enhanced. The short-period binary H 313 is a photometric variable; this supports the interpretation that it is a magnetically active binary. From the detection of the Li I 6707.8 Å line, we classify the giant in VR 84 as a first-ascent giant; this leaves its circular orbit unexplained. As a side-result we report the detection of Li I 6707.8 Å in the spectrum of the giant H 3 and the absence of this line in the spectrum of the giant H 11; this classifies H 3 as a first-ascent giant and H 11 as a core-helium-burning clump star, and confirms the faint extension of the red-giant clump in NGC 752. Based on observations made with the Jacobus Kapteyn Telescope and the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

Giant Dirac point shift of graphene phototransistors by doped silicon substrate current

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

Shimatani, Masaaki; Ogawa, Shinpei, E-mail: Ogawa.Shimpei@eb.MitsubishiElectric.co.jp; Fujisawa, Daisuke

2016-03-15

Graphene is a promising new material for photodetectors due to its excellent optical properties and high-speed response. However, graphene-based phototransistors have low responsivity due to the weak light absorption of graphene. We have observed a giant Dirac point shift upon white light illumination in graphene-based phototransistors with n-doped Si substrates, but not those with p-doped substrates. The source-drain current and substrate current were investigated with and without illumination for both p-type and n-type Si substrates. The decay time of the drain-source current indicates that the Si substrate, SiO{sub 2} layer, and metal electrode comprise a metal-oxide-semiconductor (MOS) capacitor due tomore » the presence of defects at the interface between the Si substrate and SiO{sub 2} layer. The difference in the diffusion time of the intrinsic major carriers (electrons) and the photogenerated electron-hole pairs to the depletion layer delays the application of the gate voltage to the graphene channel. Therefore, the giant Dirac point shift is attributed to the n-type Si substrate current. This phenomenon can be exploited to realize high-performance graphene-based phototransistors.« less

The Composition and Chemistry of the Deep Tropospheres of Saturn and Uranus from Ground-Based Radio Observations

NASA Astrophysics Data System (ADS)

Hofstadter, M. D.; Adumitroaie, V.; Atreya, S. K.; Butler, B.

2017-12-01

Ground-based radio observations of the giant planets at wavelengths from 1 millimeter to 1 meter have long been the primary means to study the deep tropospheres of both gas- and ice-giant planets (e.g. de Pater and Massie 1985, Icarus 62; Hofstadter and Butler 2003, Icarus 165). Most recently, radiometers aboard the Cassini and Juno spacecraft at Saturn and Jupiter, respectively, have demonstrated the ability of spaceborne systems to study composition and weather beneath the visible cloud tops with high spatial resolution (Janssen et al. 2013, Icarus 226; Bolton et al. 2016, this meeting). Ground-based observations remain, however, an excellent way to study the tropospheres of the ice giants, particularly the temporal and spatial distribution of condensible species, and to study the deep troposphere of Saturn in the region of the water cloud. This presentation focuses on two ground-based data sets, one for Uranus and one for Saturn. The Uranus data were all collected near the 2007 equinox, and span wavelengths from 0.1 to 20 cm. These data provide a snapshot of atmospheric composition at a single season. The Saturn observations were recently made with the EVLA observatory at wavelengths from 3 to 90 cm, augmented by published observations at shorter and longer wavelengths. It is expected that these data will allow us to constrain conditions in the water cloud region on Saturn. At the time of this writing, both data sets are being analyzed using an optimal estimation retrieval algorithm fed with the latest published information on the chemical and electrical properties of relevant atmospheric species (primarily H2O, NH3, H2S, PH3, and free electrons). At Uranus, we find that—consistent with previously published work—ammonia in the 1 to 50-bar range is strongly depleted from solar values. The relative volume mixing ratios of the above species satisfy PH3 < NH3 < H2S < H2O, which is interesting because based on cosmic abundances one would expect H2S < NH3. At the time of the conference, we hope to have refined estimates of the absolute mixing ratio of each species, and preliminary results on Saturn. We will discuss the implications of our results for the chemistry and composition of the giant planets, and the differences between gas- and ice-giants.

An artificial muscle model unit based on inorganic nanosheet sliding by photochemical reaction.

PubMed

Nabetani, Yu; Takamura, Hazuki; Hayasaka, Yuika; Sasamoto, Shin; Tanamura, Yoshihiko; Shimada, Tetsuya; Masui, Dai; Takagi, Shinsuke; Tachibana, Hiroshi; Tong, Zhiwei; Inoue, Haruo

2013-04-21

From the viewpoint of developing photoresponsive supramolecular systems in microenvironments to exhibit more sophisticated photo-functions even at the macroscopic level, inorganic/organic hybrid compounds based on clay or niobate nanosheets as the microenvironments were prepared, characterized, and examined for their photoreactions. We show here a novel type of artificial muscle model unit having much similarity with that in natural muscle fibrils. Upon photoirradiation, the organic/inorganic hybrid nanosheets reversibly slide horizontally on a giant scale, and the interlayer spaces in the layered hybrid structure shrink and expand vertically. In particular, our layered hybrid molecular system exhibits a macroscopic morphological change on a giant scale (~1500 nm) compared with the molecular size of ~1 nm, based on a reversible sliding mechanism.

Giant trochanteric pressure sore: Use of a pedicled chimeric perforator flap for cover

PubMed Central

Mehrotra, Sandeep

2009-01-01

Pressure sores are increasing in frequency commensurate with an ageing population with multi-system disorders and trauma. Numerous classic options are described for providing stable wound cover. With the burgeoning knowledge on perforator anatomy, recent approaches focus on the use of perforator-based flaps in bedsore surgery. A giant neglected trochanteric pressure sore in a paraplegic is presented. Since conventional options of reconstruction appeared remote, the massive ulcer was successfully managed by a chimeric perforator-based flap. The combined muscle and fasciocutaneous flaps were raised as separate paddles based on the anterolateral thigh perforator branches and provided stable cover without complications. Perforators allow versatility in managing complex wounds without compromising on established principles. PMID:19881035

Virtual cranial endocast of the oldest giant panda (Ailuropoda microta) reveals great similarity to that of its extant relative.

PubMed

Dong, Wei

2008-11-01

Recent development of computed tomography and three-dimensional visualization techniques has enabled the non-destructive inspection of the endocast morphology of fossil neurocranium, the basic material for paleoneurological study. A virtual cranial endocast was reconstructed based on the first skull of the oldest giant panda, Ailuropoda microta, discovered recently and dated at more than 2 Myr (million years) ago. It was compared with that of the extant giant panda (A. melanoleuca) and that of the polar bear (Ursus maritimus), as well as CT slices of the late Pleistocene A. baconi. The overall endocast morphology of A. microta is more similar to that of A. baconi and A. melanoleuca than to that of U. maritimus. The absolute endocast size is the smallest in A. microta, largest in A. baconi, and intermediate in A. melanoleuca. However, the proportion of cerebral volume to total endocast size is very close to each other between the oldest and extant giant panda, as well as the sulcal length per unit area of cerebral endocast surface.

New red giant star in the Kepler open cluster NGC 6819

NASA Astrophysics Data System (ADS)

Komucyeya, E.; Abedigamba, O. P.; Jurua, E.; Anguma, S. K.

2018-05-01

A recent study indicated that 39 red giant stars showing solar-like oscillations were discovered in the field of Kepleropen cluster NGC 6819. The study was based on photometric distance estimates of 27 stars out of the 39. Using photometric method alone may not be adequate to confirm the membership of these stars. The stars were not previously known in literature to belong to the open cluster NGC 6819. In this study, Kepler data was used to study the membership of the 27 stars. A plot of apparent magnitude as a function of the large frequency separation, supplemented with the proper motion and radial velocity values from literature revealed KIC 5112840 to lie on the same plane with the well known members of the cluster. Echelle diagram was constructed, and the median gravity-mode period spacings (ΔP) calculated for KIC 5112840. A value of ΔP = 66.3 s was obtained, thus placing the red giant star KIC 5112840 on the Red Giant Branch stage of evolution. Our evolutionary status result using the approach in this paper is in agreement with what is in the available literature.

Fecal Near Infrared Spectroscopy to Discriminate Physiological Status in Giant Pandas

PubMed Central

Wiedower, Erin E.; Kouba, Andrew J.; Vance, Carrie K.; Hansen, Rachel L.; Tolleson, Douglas R.

2012-01-01

Giant panda (Ailuropoda melanoleuca) monitoring and research often require accurate estimates of population size and density. However, obtaining these estimates has been challenging. Innovative technologies, such as fecal near infrared reflectance spectroscopy (FNIRS), may be used to differentiate between sex, age class, and reproductive status as has been shown for several other species. The objective of this study was to determine if FNIRS could be similarly used for giant panda physiological discriminations. Based on samples from captive animals in four U.S. zoos, FNIRS calibrations correctly identified 78% of samples from adult males, 81% from adult females, 85% from adults, 89% from juveniles, 75% from pregnant and 70% from non-pregnant females. However, diet had an impact on the success of the calibrations. When diet was controlled for plant part such that “leaf only” feces were evaluated, FNIRS calibrations correctly identified 93% of samples from adult males and 95% from adult females. These data show that FNIRS has the potential to differentiate between the sex, age class, and reproductive status in the giant panda and may be applicable for surveying wild populations. PMID:22719982

Inbreeding and inbreeding avoidance in wild giant pandas.

PubMed

Hu, Yibo; Nie, Yonggang; Wei, Wei; Ma, Tianxiao; Van Horn, Russell; Zheng, Xiaoguang; Swaisgood, Ronald R; Zhou, Zhixin; Zhou, Wenliang; Yan, Li; Zhang, Zejun; Wei, Fuwen

2017-10-01

Inbreeding can have negative consequences on population and individual fitness, which could be counteracted by inbreeding avoidance mechanisms. However, the inbreeding risk and inbreeding avoidance mechanisms in endangered species are less studied. The giant panda, a solitary and threatened species, lives in many small populations and suffers from habitat fragmentation, which may aggravate the risk of inbreeding. Here, we performed long-term observations of reproductive behaviour, sampling of mother-cub pairs and large-scale genetic analyses on wild giant pandas. Moderate levels of inbreeding were found in 21.1% of mating pairs, 9.1% of parent pairs and 7.7% of panda cubs, but no high-level inbreeding occurred. More significant levels of inbreeding may be avoided passively by female-biased natal dispersal rather than by breeding dispersal or active relatedness-based mate choice mechanisms. The level of inbreeding in giant pandas is greater than expected for a solitary mammal and thus warrants concern for potential inbreeding depression, particularly in small populations isolated by continuing habitat fragmentation, which will reduce female dispersal and increase the risk of inbreeding. © 2017 John Wiley & Sons Ltd.

Virtual cranial endocast of the oldest giant panda ( Ailuropoda microta) reveals great similarity to that of its extant relative

NASA Astrophysics Data System (ADS)

Dong, Wei

2008-11-01

Recent development of computed tomography and three-dimensional visualization techniques has enabled the non-destructive inspection of the endocast morphology of fossil neurocranium, the basic material for paleoneurological study. A virtual cranial endocast was reconstructed based on the first skull of the oldest giant panda, Ailuropoda microta, discovered recently and dated at more than 2 Myr (million years) ago. It was compared with that of the extant giant panda ( A. melanoleuca) and that of the polar bear ( Ursus maritimus), as well as CT slices of the late Pleistocene A. baconi. The overall endocast morphology of A. microta is more similar to that of A. baconi and A. melanoleuca than to that of U. maritimus. The absolute endocast size is the smallest in A. microta, largest in A. baconi, and intermediate in A. melanoleuca. However, the proportion of cerebral volume to total endocast size is very close to each other between the oldest and extant giant panda, as well as the sulcal length per unit area of cerebral endocast surface.

Seismology of Giant Planets: General Overview and Results from the Kepler K2 Observations of Neptune

NASA Astrophysics Data System (ADS)

Gaulme, Patrick

2017-10-01

For this invited contribution, I was asked to give an overview about the application of helio and aster-oseismic techniques to study the interior of giant planets, and to specifically present the recent observations of Neptune by Kepler K2. Seismology applied to giant planets could drastically change our understanding of their deep interiors, as it has happened with the Earth, the Sun, and many main-sequence and evolved stars. The study of giant planets' composition is important for understanding both the mechanisms enabling their formation and the origins of planetary systems, in particular our own. Unfortunately, its determination is complicated by the fact that their interior is thought not to be homogeneous, so that spectroscopic determinations of atmospheric abundances are probably not representative of the planet as a whole. Instead, the determination of their composition and structure must rely on indirect measurements and interior models. Giant planets are mostly fluid and convective, which makes their seismology much closer to that of solar-like stars than that of terrestrial planets. Hence, helioseismology techniques naturally transfer to giant planets. In addition, two alternative methods can be used: photometry of the solar light reflected by planetary atmospheres, and ring seismology in the specific case of Saturn. The current decade has been promising thanks to the detection of Jupiter's acoustic oscillations with the ground-based imaging-spectrometer SYMPA and indirect detection of Saturn's f-modes in its rings by the NASA Cassini orbiter. This has motivated new projects of ground-based and space-borne instruments that are under development. The K2 observations represented the first opportunity to search for planetary oscillations with visible photometry. Despite the excellent quality of K2 data, the noise level of the power spectrum of the light curve was not low enough to detect Neptune's oscillations. The main results from the K2 observations are the clear detection of the well-known differential rotation of Neptune, measured for the first time through the rotational modulation of its photometry, and the detection of the Sun's oscillations, for the first time in an indirect way in intensity measurements.

Melorheostosis and central giant cell granuloma of the mandible in a 15-year-old girl.

PubMed

Anderson, K M; Shintaku, W H; Rosebush, M S; Rawal, Y B; Woodard, E S

2013-11-01

Melorheostosis is a nonhereditary bone dysplasia primarily affecting the appendicular skeleton. Because clinical and histologic features are often nonspecific, the diagnosis is often based on the radiographic presentation. Involvement of the craniofacial skeleton is rare. We describe a case of a 15-year-old girl with appendicular and craniofacial melorheostosis with adjacent central giant cell granuloma. We discuss the possible significance of this previously unreported finding. Copyright © 2013 Elsevier Inc. All rights reserved.

Particle transport and stochastic acceleration in the giant lobes of Centaurus A

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

O'Sullivan, Stephen

2011-09-22

The conditions within the giant lobes of Centaurus A are reviewed in light of recent radio and {gamma}-ray observations. Data from WMAP and ground-based telescopes in conjunction with measurements from Fermi-LAT constrain the characteristic field strength and the maximum electron energy. The implications for the transport of energetic particles are discussed in terms of residence times and cooling times within the lobes. Acceleration of electrons and UHECR via the second order Fermi mechanism is discussed.

Remote measurement of canopy water content in giant sequoias (Sequoiadendron giganteum) during drought

USGS Publications Warehouse

Martin, Roberta E.; Asner, Gregory P.; Francis, Emily; Ambrose, Anthony; Baxter, Wendy; Das, Adrian J.; Vaughn, Nicolas R.; Paz-Kagan, Tarin; Dawson, Todd E.; Nydick, Koren R.; Stephenson, Nathan L.

2018-01-01

California experienced severe drought from 2012 to 2016, and there were visible changes in the forest canopy throughout the State. In 2014, unprecedented foliage dieback was recorded in giant sequoia (Sequoiadendron giganteum) trees in Sequoia National Park, in the southern California Sierra Nevada mountains. Although visible changes in sequoia canopies can be recorded, biochemical and physiological responses to drought stress in giant sequoia canopies are not well understood. Ground-based measurements provide insight into the mechanisms of drought responses in trees, but are often limited to few individuals, especially in trees of tall stature such as giant sequoia. Recent studies demonstrate that remotely measured forest canopy water content (CWC) is a general indicator of canopy response to drought, but the underpinning leaf- to canopy-level causes of observed variation in CWC remain poorly understood. We combined field and airborne remote sensing measurements taken in 2015 and 2016 to assess the biophysical responses of giant sequoias to drought. In 49 study trees, CWC was related to leaf water potential, but not to the other foliar traits, suggesting that changes in CWC were made at whole-canopy rather than leaf scales. We found a non-random, spatially varying pattern in mapped CWC, with lower CWC values at lower elevation and along the outer edges of the groves. This pattern was also observed in empirical measurements of foliage dieback from the ground, and in mapped CWC across multiple sequoia groves in this region, supporting the hypothesis that drought stress is expressed in canopy-level changes in giant sequoias. The fact that we can clearly detect a relationship between CWC and foliage dieback, even without taking into account prior variability or new leaf growth, strongly suggests that remotely sensed CWC, and changes in CWC, are a useful measure of water stress in giant sequoia, and valuable for assessing and managing these iconic forests in drought.

Analytical Solutions for Radiative Transfer: Implications for Giant Planet Formation by Disk Instability

NASA Astrophysics Data System (ADS)

Boss, Alan P.

2009-03-01

The disk instability mechanism for giant planet formation is based on the formation of clumps in a marginally gravitationally unstable protoplanetary disk, which must lose thermal energy through a combination of convection and radiative cooling if they are to survive and contract to become giant protoplanets. While there is good observational support for forming at least some giant planets by disk instability, the mechanism has become theoretically contentious, with different three-dimensional radiative hydrodynamics codes often yielding different results. Rigorous code testing is required to make further progress. Here we present two new analytical solutions for radiative transfer in spherical coordinates, suitable for testing the code employed in all of the Boss disk instability calculations. The testing shows that the Boss code radiative transfer routines do an excellent job of relaxing to and maintaining the analytical results for the radial temperature and radiative flux profiles for a spherical cloud with high or moderate optical depths, including the transition from optically thick to optically thin regions. These radial test results are independent of whether the Eddington approximation, diffusion approximation, or flux-limited diffusion approximation routines are employed. The Boss code does an equally excellent job of relaxing to and maintaining the analytical results for the vertical (θ) temperature and radiative flux profiles for a disk with a height proportional to the radial distance. These tests strongly support the disk instability mechanism for forming giant planets.

Improvement of genome assembly completeness and identification of novel full-length protein-coding genes by RNA-seq in the giant panda genome.

PubMed

Chen, Meili; Hu, Yibo; Liu, Jingxing; Wu, Qi; Zhang, Chenglin; Yu, Jun; Xiao, Jingfa; Wei, Fuwen; Wu, Jiayan

2015-12-11

High-quality and complete gene models are the basis of whole genome analyses. The giant panda (Ailuropoda melanoleuca) genome was the first genome sequenced on the basis of solely short reads, but the genome annotation had lacked the support of transcriptomic evidence. In this study, we applied RNA-seq to globally improve the genome assembly completeness and to detect novel expressed transcripts in 12 tissues from giant pandas, by using a transcriptome reconstruction strategy that combined reference-based and de novo methods. Several aspects of genome assembly completeness in the transcribed regions were effectively improved by the de novo assembled transcripts, including genome scaffolding, the detection of small-size assembly errors, the extension of scaffold/contig boundaries, and gap closure. Through expression and homology validation, we detected three groups of novel full-length protein-coding genes. A total of 12.62% of the novel protein-coding genes were validated by proteomic data. GO annotation analysis showed that some of the novel protein-coding genes were involved in pigmentation, anatomical structure formation and reproduction, which might be related to the development and evolution of the black-white pelage, pseudo-thumb and delayed embryonic implantation of giant pandas. The updated genome annotation will help further giant panda studies from both structural and functional perspectives.

Einstein Observatory magnitude-limited X-ray survey of late-type giant and supergiant stars

NASA Technical Reports Server (NTRS)

Maggio, A.; Vaiana, G. S.; Haisch, B. M.; Stern, R. A.; Bookbinder, J.

1990-01-01

Results are presented of an extensive X-ray survey of 380 giant and supergiant stars of spectral types from F to M, carried out with the Einstein Observatory. It was found that the observed F giants or subgiants (slightly evolved stars with a mass M less than about 2 solar masses) are X-ray emitters at the same level of main-sequence stars of similar spectral type. The G giants show a range of emissions more than 3 orders of magnitude wide; some single G giants exist with X-ray luminosities comparable to RS CVn systems, while some nearby large G giants have upper limits on the X-ray emission below typical solar values. The K giants have an observed X-ray emission level significantly lower than F and F giants. None of the 29 M giants were detected, except for one spectroscopic binary.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Several Praxair trucks begin to depart Launch Pad 39B at NASA's Kennedy Space Center in Florida, after offloading their loads of liquid oxygen, or LO2, one at a time into the giant storage sphere located at the northwest corner of the pad. The sphere was gradually chilled down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Several Praxair trucks carrying their loads of liquid oxygen, or LO2, arrive at Launch Pad 39B at NASA's Kennedy Space Center in Florida. The trucks will offload LO2 slowly into a giant storage sphere located at the northwest corner of the pad to gradually chill it down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Mist or vapor is visible as a Praxair truck slowly transfers its load of liquid oxygen, or LO2, into a giant storage sphere at the northwest corner of Launch Pad 39B at NASA's Kennedy Space Center in Florida. The sphere will gradually be chilled down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

The primary structure of the hemoglobin of spectacled bear (Tremarctos ornatus, Carnivora).

PubMed

Hofmann, O; Braunitzer, G

1987-08-01

The complete primary structure of the alpha- and beta-chains of the hemoglobin of Spectacled Bear (Tremarctos ornatus) is presented. Following cleavage of the heme-protein link and chain separation by RP-HPLC, their amino-acid sequences were determined by Edman degradation in liquid- and gas-phase sequenators. The hemoglobin of Spectacled Bear displays only five amino-acid exchanges to that of Polar Bear (Ursus maritimus, Ursinae) and Asiatic Black Bear (Ursus tibetanus, Ursinae) whereas 8 and 12 replacements, respectively, to Giant Panda (Ailuropoda melanoleuca) and Lesser Panda (Ailurus fulgens) can be found. This clearly demonstrates that the Spectacled Bear, the most aberrant bear of the Ursidae, is somewhat intermediate between Pandas and Ursinae.

Ion association at discretely-charged dielectric interfaces: Giant charge inversion

NASA Astrophysics Data System (ADS)

Wang, Zhi-Yong; Wu, Jianzhong

2017-07-01

Giant charge reversal has been identified for the first time by Monte Carlo simulation for a discretely charged surface in contact with a trivalent electrolyte solution. It takes place regardless of the surface charge density under study and the monovalent salt. In stark contrast to earlier predictions based on the 2-dimensional Wigner crystal model to describe strong correlation of counterions at the macroion surface, we find that giant charge reversal reflects an intricate interplay of ionic volume effects, electrostatic correlations, surface charge heterogeneity, and the dielectric response of the confined fluids. While the novel phenomenon is yet to be confirmed with experiment, the simulation results appear in excellent agreement with a wide range of existing observations in the subregime of charge inversion. Our findings may have far-reaching implications to understanding complex electrochemical phenomena entailing ionic fluids under dielectric confinements.

Lithium in giant stars in NGC 752 and M67

NASA Astrophysics Data System (ADS)

Pilachowski, Catherine; Saha, A.; Hobbs, L. M.

1988-04-01

Spectra of giant stars in the intermediate-age galactic cluster NGC 752 and in the old cluster M67 have been examined for the presence of Li I λ6707. The lithium feature is not present in any of the M67 giants observed, leading to upper-limit abundances of log ɛ(Li) ≤ -1.0 to 0.3. While lithium is not present in most NGC 752 giants, the feature is strong in two giants, Heinemann 77 and 208, log ɛ(Li) = +1.1 and +1.4, respectively. In the remaining giants in NGC 752, log ɛ(Li) < 0.5. The absence of lithium in M67 giants may be because these giants evolve from progenitors in the region of the main-sequence lithium dip.

PROBING THE DEEP END OF THE MILKY WAY WITH KEPLER : ASTEROSEISMIC ANALYSIS OF 854 FAINT RED GIANTS MISCLASSIFIED AS COOL DWARFS

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

Mathur, S.; García, R. A.; Beck, P. G.

Asteroseismology has proven to be an excellent tool to determine not only global stellar properties with good precision, but also to infer the stellar structure, dynamics, and evolution for a large sample of Kepler stars. Prior to the launch of the mission, the properties of Kepler targets were inferred from broadband photometry, leading to the Kepler Input Catalog (KIC). The KIC was later revised in the Kepler Star Properties Catalog, based on literature values and an asteroseismic analysis of stars that were unclassified in the KIC. Here, we present an asteroseismic analysis of 45,400 stars that were classified as dwarfsmore » in the Kepler Star Properties Catalog. We found that around 2% of the sample shows acoustic modes in the typical frequency range that put them in the red-giant category rather than the cool dwarf category. We analyze the asteroseismic properties of these stars, derive their surface gravities, masses, and radii, and present updated effective temperatures and distances. We show that the sample is significantly fainter than the previously known oscillating giants in the Kepler field, with the faintest stars reaching down to a Kepler magnitude of Kp ∼ 16. We demonstrate that 404 stars are at distances beyond 5 kpc and that the stars are significantly less massive than for the original Kepler red-giant sample, consistent with a population of distant halo giants. A comparison with a galactic population model shows that up to 40 stars might be genuine halo giants, which would increase the number of known asteroseismic halo stars by a factor of 4. The detections presented here will provide a valuable sample for galactic archeology studies.« less

Osteology of Icadyptes salasi, a giant penguin from the Eocene of Peru

PubMed Central

Ksepka, Daniel T; Clarke, Julia A; DeVries, Thomas J; Urbina, Mario

2008-01-01

We present the first detailed description of the giant Eocene penguin Icadyptes salasi. The species is characterized by a narrow skull with a hyper-elongate spear-like beak, a robust cervical column and a powerful flipper. The bony beak tip of Icadyptes is formed by fusion of several elements and is unique among penguins, differing markedly from previously described giant penguin beaks. Vascular canal patterning similar to that of boobies, frigatebirds and albatrosses suggests I. salasi may have had a thin, sheet-like rhamphotheca unlike the thick rugose rhamphotheca of modern penguins. Together, these features suggest a novel ecology for I. salasi, most likely involving the capture of larger prey items via spearing. As the first described giant penguin specimen to preserve a complete wing skeleton, the I. salasi holotype yields significant insight into the shape, proportions and orientation of the wing in giant penguins. In articulation, the forelimb of I. salasi is straighter, permitting less manus and antibrachium flexion, than previous depictions of giant penguin wings. Cross-sections of the humerus and ulna reveal a level of osteosclerosis equalling or surpassing that of extant penguins. Based on ontogenetic data from extant penguins and the morphology of the carpometacarpus of I. salasi, we infer the retention of a free alular phalanx in basal penguins. Previously, the status of this element in penguins was disputed. Differences in the proportions of the manual phalanges contribute to a more abruptly tapering wingtip in I. salasi compared with crown penguins. Fossils from Peru, including the I. salasi holotype specimen, document that penguins expanded to nearly the whole of their extant latitudinal range early in their evolutionary history and during one of the warmest intervals in the Cenozoic. PMID:18564073

STRUCTURAL GLITCHES NEAR THE CORES OF RED GIANTS REVEALED BY OSCILLATIONS IN G-MODE PERIOD SPACINGS FROM STELLAR MODELS

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

Cunha, M. S.; Avelino, P. P.; Stello, D.

2015-06-01

With recent advances in asteroseismology it is now possible to peer into the cores of red giants, potentially providing a way to study processes such as nuclear burning and mixing through their imprint as sharp structural variations—glitches—in the stellar cores. Here we show how such core glitches can affect the oscillations we observe in red giants. We derive an analytical expression describing the expected frequency pattern in the presence of a glitch. This formulation also accounts for the coupling between acoustic and gravity waves. From an extensive set of canonical stellar models we find glitch-induced variation in the period spacingmore » and inertia of non-radial modes during several phases of red giant evolution. Significant changes are seen in the appearance of mode amplitude and frequency patterns in asteroseismic diagrams such as the power spectrum and the échelle diagram. Interestingly, along the red giant branch glitch-induced variation occurs only at the luminosity bump, potentially providing a direct seismic indicator of stars in that particular evolution stage. Similarly, we find the variation at only certain post-helium-ignition evolution stages, namely, in the early phases of helium core burning and at the beginning of helium shell burning, signifying the asymptotic giant branch bump. Based on our results, we note that assuming stars to be glitch-free, while they are not, can result in an incorrect estimate of the period spacing. We further note that including diffusion and mixing beyond classical Schwarzschild could affect the characteristics of the glitches, potentially providing a way to study these physical processes.« less

Factors affecting genotyping success in giant panda fecal samples.

PubMed

Zhu, Ying; Liu, Hong-Yi; Yang, Hai-Qiong; Li, Yu-Dong; Zhang, He-Min

2017-01-01

Fecal samples play an important role in giant panda conservation studies. Optimal preservation conditions and choice of microsatellites for giant panda fecal samples have not been established. In this study, we evaluated the effect of four factors (namely, storage type (ethanol (EtOH), EtOH -20 °C, 2-step storage medium, DMSO/EDTA/Tris/salt buffer (DETs) and frozen at -20 °C), storage time (one, three and six months), fragment length, and repeat motif of microsatellite loci) on the success rate of microsatellite amplification, allelic dropout (ADO) and false allele (FA) rates from giant panda fecal samples. Amplification success and ADO rates differed between the storage types. Freezing was inferior to the other four storage methods based on the lowest average amplification success and the highest ADO rates ( P < 0.05). The highest microsatellite amplification success was obtained from either EtOH or the 2-step storage medium at three storage time points. Storage time had a negative effect on the average amplification of microsatellites and samples stored in EtOH and the 2-step storage medium were more stable than the other three storage types. We only detected the effect of repeat motif on ADO and FA rates. The lower ADO and FA rates were obtained from tri- and tetra-nucleotide loci. We suggest that freezing should not be used for giant panda fecal preservation in microsatellite studies, and EtOH and the 2-step storage medium should be chosen on priority for long-term storage. We recommend candidate microsatellite loci with longer repeat motif to ensure greater genotyping success for giant panda fecal studies.

Evaluating Landscape Options for Corridor Restoration between Giant Panda Reserves

PubMed Central

Wang, Fang; McShea, William J.; Wang, Dajun; Li, Sheng; Zhao, Qing; Wang, Hao; Lu, Zhi

2014-01-01

The establishment of corridors can offset the negative effects of habitat fragmentation by connecting isolated habitat patches. However, the practical value of corridor planning is minimal if corridor identification is not based on reliable quantitative information about species-environment relationships. An example of this need for quantitative information is planning for giant panda conservation. Although the species has been the focus of intense conservation efforts for decades, most corridor projects remain hypothetical due to the lack of reliable quantitative researches at an appropriate spatial scale. In this paper, we evaluated a framework for giant panda forest corridor planning. We linked our field survey data with satellite imagery, and conducted species occupancy modelling to examine the habitat use of giant panda within the potential corridor area. We then conducted least-cost and circuit models to identify potential paths of dispersal across the landscape, and compared the predicted cost under current conditions and alternative conservation management options considered during corridor planning. We found that due to giant panda's association with areas of low elevation and flat terrain, human infrastructures in the same area have resulted in corridor fragmentation. We then identified areas with high potential to function as movement corridors, and our analysis of alternative conservation scenarios showed that both forest/bamboo restoration and automobile tunnel construction would significantly improve the effectiveness of corridor, while residence relocation would not significantly improve corridor effectiveness in comparison with the current condition. The framework has general value in any conservation activities that anticipate improving habitat connectivity in human modified landscapes. Specifically, our study suggested that, in this landscape, automobile tunnels are the best means to remove current barriers to giant panda movements caused by anthropogenic interferences. PMID:25133757

Factors affecting genotyping success in giant panda fecal samples

PubMed Central

Zhu, Ying; Liu, Hong-Yi; Yang, Hai-Qiong; Li, Yu-Dong

2017-01-01

Fecal samples play an important role in giant panda conservation studies. Optimal preservation conditions and choice of microsatellites for giant panda fecal samples have not been established. In this study, we evaluated the effect of four factors (namely, storage type (ethanol (EtOH), EtOH −20 °C, 2-step storage medium, DMSO/EDTA/Tris/salt buffer (DETs) and frozen at −20 °C), storage time (one, three and six months), fragment length, and repeat motif of microsatellite loci) on the success rate of microsatellite amplification, allelic dropout (ADO) and false allele (FA) rates from giant panda fecal samples. Amplification success and ADO rates differed between the storage types. Freezing was inferior to the other four storage methods based on the lowest average amplification success and the highest ADO rates (P < 0.05). The highest microsatellite amplification success was obtained from either EtOH or the 2-step storage medium at three storage time points. Storage time had a negative effect on the average amplification of microsatellites and samples stored in EtOH and the 2-step storage medium were more stable than the other three storage types. We only detected the effect of repeat motif on ADO and FA rates. The lower ADO and FA rates were obtained from tri- and tetra-nucleotide loci. We suggest that freezing should not be used for giant panda fecal preservation in microsatellite studies, and EtOH and the 2-step storage medium should be chosen on priority for long-term storage. We recommend candidate microsatellite loci with longer repeat motif to ensure greater genotyping success for giant panda fecal studies. PMID:28560107

OCEANUS: A high science return Uranus orbiter with a low-cost instrument suite

NASA Astrophysics Data System (ADS)

Elder, C. M.; Bramson, A. M.; Blum, L. W.; Chilton, H. T.; Chopra, A.; Chu, C.; Das, A.; Davis, A. B.; Delgado, A.; Fulton, J.; Jozwiak, L. M.; Khayat, A.; Landis, M. E.; Molaro, J. L.; Slipski, M.; Valencia, S.; Watkins, J.; Young, C. L.; Budney, C. J.; Mitchell, K. L.

2018-07-01

Ice-giant-sized planets are the most common type of observed exoplanet, yet the two ice giants in our own solar system (Uranus and Neptune) are the least explored class of planet, having only been observed through ground-based observations and a single flyby each by Voyager 2 approximately 30 years ago. These single flybys were unable to characterize the spatial and temporal variability in ice giant magnetospheres, some of the most odd and intriguing magnetospheres in the solar system. They also offered only limited constraints on the internal structure of ice giants; understanding the internal structure of a planet is important for understanding its formation and evolution. The most recent planetary science Decadal Survey by the U.S. National Academy of Sciences, "Vision and Voyages for Planetary Science in the Decade 2013-2022," identified the ice giant Uranus as the third highest priority for a Flagship mission in the decade 2013-2022. However, in the event that NASA or another space agency is unable to fly a Flagship-class mission to an ice giant in the next decade, this paper presents a mission concept for a focused, lower cost Uranus orbiter called OCEANUS (Origins and Composition of the Exoplanet Analog Uranus System). OCEANUS would increase our understanding of the interior structure of Uranus, its magnetosphere, and how its magnetic field is generated. These goals could be achieved with just a magnetometer and the spacecraft's radio system. This study shows that several of the objectives outlined by the Decadal Survey, including one of the two identified as highest priority, are within reach for a New-Frontiers-class mission.

Evaluating landscape options for corridor restoration between giant panda reserves.

PubMed

Wang, Fang; McShea, William J; Wang, Dajun; Li, Sheng; Zhao, Qing; Wang, Hao; Lu, Zhi

2014-01-01

The establishment of corridors can offset the negative effects of habitat fragmentation by connecting isolated habitat patches. However, the practical value of corridor planning is minimal if corridor identification is not based on reliable quantitative information about species-environment relationships. An example of this need for quantitative information is planning for giant panda conservation. Although the species has been the focus of intense conservation efforts for decades, most corridor projects remain hypothetical due to the lack of reliable quantitative researches at an appropriate spatial scale. In this paper, we evaluated a framework for giant panda forest corridor planning. We linked our field survey data with satellite imagery, and conducted species occupancy modelling to examine the habitat use of giant panda within the potential corridor area. We then conducted least-cost and circuit models to identify potential paths of dispersal across the landscape, and compared the predicted cost under current conditions and alternative conservation management options considered during corridor planning. We found that due to giant panda's association with areas of low elevation and flat terrain, human infrastructures in the same area have resulted in corridor fragmentation. We then identified areas with high potential to function as movement corridors, and our analysis of alternative conservation scenarios showed that both forest/bamboo restoration and automobile tunnel construction would significantly improve the effectiveness of corridor, while residence relocation would not significantly improve corridor effectiveness in comparison with the current condition. The framework has general value in any conservation activities that anticipate improving habitat connectivity in human modified landscapes. Specifically, our study suggested that, in this landscape, automobile tunnels are the best means to remove current barriers to giant panda movements caused by anthropogenic interferences.

A Differential Chemical Element Analysis of the Metal-poor Globular Cluster NGC 6397

NASA Astrophysics Data System (ADS)

Koch, Andreas; McWilliam, Andrew

2011-08-01

We present chemical abundances in three red giants and two turnoff (TO) stars in the metal-poor Galactic globular cluster (GC) NGC 6397 based on spectroscopy obtained with the Magellan Inamori Kyocera Echelle high-resolution spectrograph on the Magellan 6.5 m Clay telescope. Our results are based on a line-by-line differential abundance analysis relative to the well-studied red giant Arcturus and the Galactic halo field star Hip 66815. At a mean of -2.10 ± 0.02 (stat.) ±0.07 (sys.), the differential iron abundance is in good agreement with other studies in the literature based on gf-values. As in previous differential works we find a distinct departure from ionization equilibrium in that the abundances of Fe I and Fe II differ by ~0.1 dex, with opposite signs for the red giant branch (RGB) and TO stars. The α-element ratios are enhanced to 0.4 (RGB) and 0.3 dex (TO), respectively, and we also confirm strong variations in the O, Na, and Al/Fe abundance ratios. Accordingly, the light-element abundance patterns in one of the red giants can be attributed to pollution by an early generation of massive Type II supernovae. TO and RGB abundances are not significantly different, with the possible exception of Mg and Ti, which are, however, amplified by the patterns in one TO star additionally belonging to this early generation of GC stars. We discuss interrelations of these light elements as a function of the GC metallicity. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Fluid Characteristics in the Giant Quartz Reef System of the Bundelkhand Craton, India: Constraints from Fluid Inclusion Study

NASA Astrophysics Data System (ADS)

Rout, D.; Panigrahi, M. K.; Pati, J. K.

2017-12-01

Giant quartz reefs are anomalous features indicating extensive mobilization of silica in the crust. Such reefs in the Abitibi belt, Canada and elsewhere are believed to be the result of activity of fluid of diverse sources on terrain boundaries. The Bundelkhand granitoid complex constituting a major part of the Bundelkhnad Craton in north-Central India is traversed by numerous such quartz reefs all across for a length of about 500 km. There are about 20 major reefs having dimensions of 35 to 40 km in length, 50 to 60 m in width standing out as prominent ridges in the region. Almost all are aligned parallel to each other in a sub-vertical to vertical manner following the NE-SW to NNE-SSW trend. Fluid inclusion petrography in quartz from these reefs reveal four types of inclusions viz. aqueous biphase (type-I), pure carbonic (type-II), aqueous carbonic (type-III) and polyphase (type-IV) inclusions. The type-I aqueous biphase inclusions are the dominant type in all the samples studied so far. Salinities calculated from temperature of melting of last ice (Tm) values are low to moderate, ranging from 0.18 to 18.19 wt% NaCl equivalents. Temperature of liquid-vapor homogenization (Th) values of these inclusions show a wide range from 101 ºC to 386 ºC (cluster around 150-250 ºC) essentially into liquid phase ruling out boiling during its course of evolution. Besides, aqueous Biphase inclusions, some data on pure CO2 inclusions furnish a near constant value of TmCO2 at -56.6 ºC in the Bundelkhand Craton indicating absence of CH4. Bivariate plot between Th and salinity suggest three possible water types which are controlling the overall activity of fluid in quartz reefs of Bundelkhand Craton viz. low-T low saline, high-T low saline and moderate-T and moderate saline. A low saline and CO2-bearing and higher temperature nature resembles a metamorphic fluid that may be a source for these giant quartz reefs. The low temperature low-salinity component could be a meteoric fluid that possibly mixed with a moderate salinity fluid. Such a moderate salinity fluid could represent a magmatic fluid that evolved to such low temperatures through prolonged fluid rock interaction. Although these quartz reefs do not bear any economic grade mineralization, the fluid characteristics compare well with mineralized reefs in the Dharwar and Bastar cratons.

Design and numerical simulation of novel giant magnetostrictive ultrasonic transducer

NASA Astrophysics Data System (ADS)

Li, Pengyang; Liu, Qiang; Li, Shujuan; Wang, Quandai; Zhang, Dongya; Li, Yan

This paper provides a design method of a novel giant magnetostrictive ultrasonic transducer utilized in incremental sheet metal forming. The frequency equations of the ultrasonic vibrator were deduced and the corresponding correctness verified by the modal and harmonic response characteristic through the finite element method (FEM) and ANSYS software. In addition, the magnetic field of the vibrator system was designed and verified by the ANSYS. Finally, the frequency tests based on the impedance response analysis and the amplitude measurements based on the laser displacement sensor were performed on the prototype. The results confirmed the appropriate design of this transducer, setting the foundation for a low mechanical quality factor and satisfying amplitude.

Air pollution from future giant jetports

NASA Technical Reports Server (NTRS)

Fay, J. A.

1970-01-01

Because aircraft arrive and depart in a generally upwind direction, the pollutants are deposited in a narrow corridor extending downwind of the airport. Vertical mixing in the turbulent atmosphere will not dilute such a trail, since the pollutants are distributed vertically during the landing and take-off operations. As a consequence, airport pollution may persist twenty to forty miles downwind without much attenuation. Based on this simple meteorological model, calculations of the ambient levels of nitric oxide and particulates to be expected downwind of a giant jetport show them to be about equal to those in present urban environments. These calculations are based on measured emission rates from jet engines and estimates of aircraft performance and traffic for future jetports.

Giant Plasma Membrane Vesicles: An Experimental Tool for Probing the Effects of Drugs and Other Conditions on Membrane Domain Stability.

PubMed

Gerstle, Zoe; Desai, Rohan; Veatch, Sarah L

2018-01-01

Giant plasma membrane vesicles (GPMVs) are isolated directly from living cells and provide an alternative to vesicles constructed of synthetic or purified lipids as an experimental model system for use in a wide range of assays. GPMVs capture much of the compositional protein and lipid complexity of intact cell plasma membranes, are filled with cytoplasm, and are free from contamination with membranes from internal organelles. GPMVs often exhibit a miscibility transition below the growth temperature of their parent cells. GPMVs labeled with a fluorescent protein or lipid analog appear uniform on the micron-scale when imaged above the miscibility transition temperature, and separate into coexisting liquid domains with differing membrane compositions and physical properties below this temperature. The presence of this miscibility transition in isolated GPMVs suggests that a similar phase-like heterogeneity occurs in intact plasma membranes under growth conditions, albeit on smaller length scales. In this context, GPMVs provide a simple and controlled experimental system to explore how drugs and other environmental conditions alter the composition and stability of phase-like domains in intact cell membranes. This chapter describes methods to generate and isolate GPMVs from adherent mammalian cells and to interrogate their miscibility transition temperatures using fluorescence microscopy. © 2018 Elsevier Inc. All rights reserved.

Magnetocardiography with sensors based on giant magnetoresistance

NASA Astrophysics Data System (ADS)

Pannetier-Lecoeur, M.; Parkkonen, L.; Sergeeva-Chollet, N.; Polovy, H.; Fermon, C.; Fowley, C.

2011-04-01

Biomagnetic signals, mostly due to the electrical activity in the body, are very weak and they can only be detected by the most sensitive magnetometers, such as Superconducting Quantum Interference Devices (SQUIDs). We report here biomagnetic recordings with hybrid sensors based on Giant MagnetoResistance (GMR). We recorded magnetic signatures of the electric activity of the human heart (magnetocardiography) in healthy volunteers. The P-wave and QRS complex, known from the corresponding electric recordings, are clearly visible in the recordings after an averaging time of about 1 min. Multiple recordings at different locations over the chest yielded a dipolar magnetic field map and allowed localizing the underlying current sources. The sensitivity of the GMR-based sensors is now approaching that of SQUIDs and paves way for spin electronics devices for functional imaging of the body.

Dramatic impact of the giant local magnetic fields on spin-dependent recombination processes in gadolinium based garnets

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

Romanov, N. G., E-mail: nikolai.romanov@mail.ioffe.ru; Tolmachev, D. O.; Gurin, A. S.

2015-06-29

A giant magnetic field effect on spin-dependent recombination of the radiation-induced defects has been found in cerium doped gadolinium based garnet crystals and ceramics, promising materials for scintillator applications. A sharp and strong increase in the afterglow intensity stimulated by external magnetic field and an evidence of the magnetic field memory have been discovered. The effect was ascribed to huge Gd-induced internal magnetic fields, which suppress the recombination, and cross-relaxation with Gd{sup 3+} ions leading to reorientation of the spins of the electron and hole centers. Thus, the spin system of radiation-induced defects in gadolinium garnet based scintillator materials wasmore » shown to accumulate significant energy which can be released in external magnetic fields.« less

New Asteroseismic Scaling Relations Based on the Hayashi Track Relation Applied to Red Giant Branch Stars in NGC 6791 and NGC 6819

NASA Astrophysics Data System (ADS)

Wu, T.; Li, Y.; Hekker, S.

2014-01-01

Stellar mass M, radius R, and gravity g are important basic parameters in stellar physics. Accurate values for these parameters can be obtained from the gravitational interaction between stars in multiple systems or from asteroseismology. Stars in a cluster are thought to be formed coevally from the same interstellar cloud of gas and dust. The cluster members are therefore expected to have some properties in common. These common properties strengthen our ability to constrain stellar models and asteroseismically derived M, R, and g when tested against an ensemble of cluster stars. Here we derive new scaling relations based on a relation for stars on the Hayashi track (\\sqrt{T_eff} \\sim g^pR^q) to determine the masses and metallicities of red giant branch stars in open clusters NGC 6791 and NGC 6819 from the global oscillation parameters Δν (the large frequency separation) and νmax (frequency of maximum oscillation power). The Δν and νmax values are derived from Kepler observations. From the analysis of these new relations we derive: (1) direct observational evidence that the masses of red giant branch stars in a cluster are the same within their uncertainties, (2) new methods to derive M and z of the cluster in a self-consistent way from Δν and νmax, with lower intrinsic uncertainties, and (3) the mass dependence in the Δν - νmax relation for red giant branch stars.

78 FR 50346 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

... large medium or giant BFT to three large medium or giant BFT for the September, October through November... retention limit of one large medium or giant BFT (measuring 73 inches (185 cm) curved fork length (CFL) or... one large medium or giant BFT as follows: Two large medium or giant BFT for January (76 FR 76900...

A young Moon-forming giant impact at 70-110 million years accompanied by late-stage mixing, core formation and degassing of the Earth.

PubMed

Halliday, Alex N

2008-11-28

New W isotope data for lunar metals demonstrate that the Moon formed late in isotopic equilibrium with the bulk silicate Earth (BSE). On this basis, lunar Sr isotope data are used to define the former composition of the Earth and hence the Rb-Sr age of the Moon, which is 4.48+/-0.02Ga, or 70-110Ma (million years) after the start of the Solar System. This age is significantly later than had been deduced from W isotopes based on model assumptions or isotopic effects now known to be cosmogenic. The Sr age is in excellent agreement with earlier estimates based on the time of lunar Pb loss and the age of the early lunar crust (4.46+/-0.04Ga). Similar ages for the BSE are recorded by xenon and lead-lead, providing evidence of catastrophic terrestrial degassing, atmospheric blow-off and significant late core formation accompanying the ca 100Ma giant impact. Agreement between the age of the Moon based on the Earth's Rb/Sr and the lead-lead age of the Moon is consistent with no major losses of moderately volatile elements from the Earth during the giant impact. The W isotopic composition of the BSE can be explained by end member models of (i) gradual accretion with a mean life of roughly 35Ma or (ii) rapid growth with a mean life of roughly 10Ma, followed by a significant hiatus prior to the giant impact. The former assumes that approximately 60 per cent of the incoming metal from impactors is added directly to the core during accretion. The latter includes complete mixing of all the impactor material into the BSE during accretion. The identical W isotopic composition of the Moon and the BSE limits the amount of material that can be added as a late veneer to the Earth after the giant impact to less than 0.3+/-0.3 per cent of ordinary chondrite or less than 0.5+/-0.6 per cent CI carbonaceous chondrite based on their known W isotopic compositions. Neither of these on their own is sufficient to explain the inventories of both refractory siderophiles such as platinum group elements and rhenium, and volatiles such as sulphur, carbon and water.

Influence of plasmon coupling on the photoluminescence of ZnS/Ag nanoparticles obtained by laser irradiation in liquid

NASA Astrophysics Data System (ADS)

Moos, Rafaela; Graff, Ismael L.; de Oliveira, Vinicius S.; Schreiner, Wido H.; Bezerra, Arandi G.

2017-10-01

We investigate the photoluminescence, optical absorption and structural properties of ZnS submitted to laser irradiation in water and isopropyl alcohol. Nanoparticles were produced by irradiating micro-sized ZnS particles dispersed in both liquids, with and without the addition of Ag nanoparticles, taking advantage of the laser-assisted fragmentation effect. When ZnS microparticles are irradiated either in pure water or isopropyl alcohol a considerable size reduction is achieved (from micra to few nanometers). The photoluminescence of these nanoparticles mainly occurs in the UV, centered at 350 nm, and with smaller intensity in the visible, centered at 600 nm. Irradiation of ZnS microparticles dispersed in colloidal silver triggers a reaction between both materials, modifying its optical absorption and photoluminescent properties. After irradiation of ZnS in alcohol containing Ag nanoparticles, a giant increase of the UV photoluminescence is observed. Interestingly, when the irradiation is performed in aqueous Ag nanoparticles colloids, the photoluminescence suffers a red-shift towards the violet-blue. The data show that core-shell (Ag-ZnO) nanostructures are formed after irradiation and the visible emission likely originates from the ZnO shell grown around silver nanoparticles. The presence of Ag nanoparticles in the liquid medium promotes a stronger absorption of the laser beam during irradiation due to the coupling with the surface plasmon resonance, fostering intense reactions among ZnS, Ag nanoparticles, and the liquid medium. Our study shows that with a simple change of the liquid medium wherein the irradiation is conducted the photoluminescence can be tuned from UV to visible and core-shell nanostructures can be obtained.

Argon purification studies and a novel liquid argon re-circulation system

NASA Astrophysics Data System (ADS)

Mavrokoridis, K.; Calland, R. G.; Coleman, J.; Lightfoot, P. K.; McCauley, N.; McCormick, K. J.; Touramanis, C.

2011-08-01

Future giant liquid argon (LAr) time projection chambers (TPCs) require a purity of better than 0.1 parts per billion (ppb) to allow the ionised electrons to drift without significant capture by any electronegative impurities. We present a comprehensive study of the effects of electronegative impurity on gaseous and liquid argon scintillation light, an analysis of the efficiency of various purification chemicals, as well as the Liverpool LAr setup, which utilises a novel re-circulation purification system. Of the impurities tested - Air, O2, H2O, N2 and CO2 in the range of between 0.01 ppm to 1000 ppm - H2O was found to have the most profound effect on gaseous argon scintillation light, and N2 was found to have the least. Additionally, a correlation between the slow component decay time and the total energy deposited with 0.01 ppm - 100 ppm O2 contamination levels in liquid argon has been established. The superiority of molecular sieves over anhydrous complexes at absorbing Ar gas, N2 gas and H2O vapour has been quantified using BET isotherm analysis. The efficiency of Cu and P2O5 at removing O2 and H2O impurities from 1 bar N6 argon gas at both room temperature and -130 °C was investigated and found to be high. A novel, highly scalable LAr re-circulation system has been developed. The complete system, consisting of a motorised bellows pump operating in liquid and a purification cartridge, were designed and built in-house. The system was operated successfully over many days and achieved a re-circulation rate of 27 litres/hour and high purity.

Giant electromechanical coupling of relaxor ferroelectrics controlled by polar nanoregion vibrations

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

Manley, Michael E.; Abernathy, Douglas L.; Sahul, Raffi

Relaxor-based ferroelectrics are prized for their giant electromechanical coupling and have revolutionized sensor and ultrasound applications. A long-standing challenge for piezoelectric materials has been to understand how these ultrahigh electromechanical responses occur when the polar atomic displacements underlying the response are partially broken into polar nanoregions (PNRs) in relaxor-based ferroelectrics. Given the complex inhomogeneous nanostructure of these materials, it has generally been assumed that this enhanced response must involve complicated interactions. By using neutron scattering measurements of lattice dynamics and local structure, we show that the vibrational modes of the PNRs enable giant coupling by softening the underlying macrodomain polarizationmore » rotations in relaxor-based ferroelectric PMN-xPT {(1 x)[Pb(Mg 1/3Nb 2/3)O 3] xPbTiO 3} (x = 30%). The mechanism involves the collective motion of the PNRs with transverse acoustic phonons and results in two hybrid modes, one softer and one stiffer than the bare acoustic phonon. The softer mode is the origin of macroscopic shear softening. Furthermore, a PNR mode and a component of the local structure align in an electric field; this further enhances shear softening, revealing a way to tune the ultrahigh piezoelectric response by engineering elastic shear softening.« less

Giant electromechanical coupling of relaxor ferroelectrics controlled by polar nanoregion vibrations

PubMed Central

Manley, Michael E.; Abernathy, Douglas L.; Sahul, Raffi; Parshall, Daniel E.; Lynn, Jeffrey W.; Christianson, Andrew D.; Stonaha, Paul J.; Specht, Eliot D.; Budai, John D.

2016-01-01

Relaxor-based ferroelectrics are prized for their giant electromechanical coupling and have revolutionized sensor and ultrasound applications. A long-standing challenge for piezoelectric materials has been to understand how these ultrahigh electromechanical responses occur when the polar atomic displacements underlying the response are partially broken into polar nanoregions (PNRs) in relaxor-based ferroelectrics. Given the complex inhomogeneous nanostructure of these materials, it has generally been assumed that this enhanced response must involve complicated interactions. By using neutron scattering measurements of lattice dynamics and local structure, we show that the vibrational modes of the PNRs enable giant coupling by softening the underlying macrodomain polarization rotations in relaxor-based ferroelectric PMN-xPT {(1 − x)[Pb(Mg1/3Nb2/3)O3] – xPbTiO3} (x = 30%). The mechanism involves the collective motion of the PNRs with transverse acoustic phonons and results in two hybrid modes, one softer and one stiffer than the bare acoustic phonon. The softer mode is the origin of macroscopic shear softening. Furthermore, a PNR mode and a component of the local structure align in an electric field; this further enhances shear softening, revealing a way to tune the ultrahigh piezoelectric response by engineering elastic shear softening. PMID:27652338

Mass and age of red giant branch stars observed with LAMOST and Kepler

NASA Astrophysics Data System (ADS)

Wu, Yaqian; Xiang, Maosheng; Bi, Shaolan; Liu, Xiaowei; Yu, Jie; Hon, Marc; Sharma, Sanjib; Li, Tanda; Huang, Yang; Liu, Kang; Zhang, Xianfei; Li, Yaguang; Ge, Zhishuai; Tian, Zhijia; Zhang, Jinghua; Zhang, Jianwei

2018-04-01

Obtaining accurate and precise masses and ages for large numbers of giant stars is of great importance for unraveling the assemblage history of the Galaxy. In this paper, we estimate masses and ages of 6940 red giant branch (RGB) stars with asteroseismic parameters deduced from Kepler photometry and stellar atmospheric parameters derived from LAMOST spectra. The typical uncertainties of mass is a few per cent, and that of age is ˜20 per cent. The sample stars reveal two separate sequences in the age-[α/Fe] relation - a high-α sequence with stars older than ˜8 Gyr and a low-α sequence composed of stars with ages ranging from younger than 1 Gyr to older than 11 Gyr. We further investigate the feasibility of deducing ages and masses directly from LAMOST spectra with a machine learning method based on kernel based principal component analysis, taking a sub-sample of these RGB stars as a training data set. We demonstrate that ages thus derived achieve an accuracy of ˜24 per cent. We also explored the feasibility of estimating ages and masses based on the spectroscopically measured carbon and nitrogen abundances. The results are quite satisfactory and significantly improved compared to the previous studies.

Giant electromechanical coupling of relaxor ferroelectrics controlled by polar nanoregion vibrations

DOE PAGES

Manley, Michael E.; Abernathy, Douglas L.; Sahul, Raffi; ...

2016-09-01

Relaxor-based ferroelectrics are prized for their giant electromechanical coupling and have revolutionized sensor and ultrasound applications. A long-standing challenge for piezoelectric materials has been to understand how these ultrahigh electromechanical responses occur when the polar atomic displacements underlying the response are partially broken into polar nanoregions (PNRs) in relaxor-based ferroelectrics. Given the complex inhomogeneous nanostructure of these materials, it has generally been assumed that this enhanced response must involve complicated interactions. By using neutron scattering measurements of lattice dynamics and local structure, we show that the vibrational modes of the PNRs enable giant coupling by softening the underlying macrodomain polarizationmore » rotations in relaxor-based ferroelectric PMN-xPT {(1 x)[Pb(Mg 1/3Nb 2/3)O 3] xPbTiO 3} (x = 30%). The mechanism involves the collective motion of the PNRs with transverse acoustic phonons and results in two hybrid modes, one softer and one stiffer than the bare acoustic phonon. The softer mode is the origin of macroscopic shear softening. Furthermore, a PNR mode and a component of the local structure align in an electric field; this further enhances shear softening, revealing a way to tune the ultrahigh piezoelectric response by engineering elastic shear softening.« less

The Optical Gravitational Lensing Experiment. Small Amplitude Variable Red Giants in the Magellanic Clouds

NASA Astrophysics Data System (ADS)

Soszynski, I.; Udalski, A.; Kubiak, M.; Szymanski, M.; Pietrzynski, G.; Zebrun, K.; Szewczyk, O.; Wyrzykowski, L.

2004-06-01

We present analysis of the large sample of variable red giants from the Large and Small Magellanic Clouds detected during the second phase of the Optical Gravitational Lensing Experiment (OGLE-II) and supplemented with OGLE-III photometry. Comparing pulsation properties of detected objects we find that they constitute two groups with clearly distinct features. In this paper we analyze in detail small amplitude variable red giants (about 15400 and 3000 objects in the LMC and SMC, respectively). The vast majority of these objects are multi-periodic. At least 30% of them exhibit two modes closely spaced in the power spectrum, what likely indicates non-radial oscillations. About 50% exhibit additional so called Long Secondary Period. To distinguish between AGB and RGB red giants we compare PL diagrams of multi-periodic red giants located above and below the tip of the Red Giant Branch (TRGB). The giants above the TRGB form four parallel ridges in the PL diagram. Among much more numerous sample of giants below the TRGB we find objects located on the low luminosity extensions of these ridges, but most of the stars are located on the ridges slightly shifted in log P. We interpret the former as the second ascent AGB red giants and the latter as the first ascent RGB objects. Thus, we empirically show that the pulsating red giants fainter than the TRGB are a mixture of RGB and AGB giants. Finally, we compare the Petersen diagrams of the LMC, SMC and Galactic bulge variable red giants and find that they are basically identical indicating that the variable red giants in all these different stellar environments share similar pulsation properties.

Serendipitous discovery of an irregular and a semi-regular type variable in the field of BY Draconis

NASA Astrophysics Data System (ADS)

Messina, S.; Marino, G.; Rodonò, M.; Cutispoto, G.

2000-12-01

We present new evidence of the optical variability of two red giant stars: HD 172468 and HK Dra, based on photometric and spectroscopic observations. These stars had been included as check stars in our photometric monitoring program of BY Dra and turned out to be variable. HD 172468, whereas almost constant for most of the time, suddenly started to drop in brightness to such a low level to become undetectable. We suspect that such an abrupt event may be an ``obscurational'' minimum, that is typical of eruptive RCB stars, or may be due to the variable extinction by circumstellar dust in a young Orion type object. HK Dra, already known as an irregular variable, is characterised by periodic flux modulation with season-to-season changes of the photometric period, as inferred from a periodogram analysis. It also shows changes of the light curve peak-to-peak amplitude and shape. Such a behaviour in giant stars is commonly found among semi-regular giants (SR) at the Asymptotic Giant Branch (AGB). Our radial velocity measurements rule out that HK Dra may be a close binary system.

A New Giant Stellar Structure in the Outer Halo of M31

NASA Astrophysics Data System (ADS)

Zucker, Daniel B.; Kniazev, Alexei Y.; Bell, Eric F.; Martínez-Delgado, David; Grebel, Eva K.; Rix, Hans-Walter; Rockosi, Constance M.; Holtzman, Jon A.; Walterbos, Rene A. M.; Ivezić, Željko; Brinkmann, J.; Brewington, Howard; Harvanek, Michael; Kleinman, S. J.; Krzesinski, Jurek; Lamb, Don Q.; Long, Dan; Newman, Peter R.; Nitta, Atsuko; Snedden, Stephanie A.

2004-09-01

The Sloan Digital Sky Survey has revealed an overdensity of luminous red giant stars ~3° (40 projected kpc) to the northeast of M31, which we have called Andromeda NE. The line-of-sight distance to Andromeda NE is within ~50 kpc of M31; Andromeda NE is not a physically unrelated projection. Andromeda NE has a g-band absolute magnitude of ~-11.6 and a central surface brightness of ~29 mag arcsec-2, making it nearly 2 orders of magnitude more diffuse than any known Local Group dwarf galaxy at that luminosity. Based on its distance and morphology, Andromeda NE is likely undergoing tidal disruption. Andromeda NE's red giant branch color is unlike that of M31's present-day outer disk or the stellar stream reported by Ibata et al., arguing against a direct link between Andromeda NE and these structures. However, Andromeda NE has a red giant branch color similar to that of the G1 clump; it is possible that these structures are both material torn off of M31's disk in the distant past or that these are both part of one ancient stellar stream.

Symbiotic stars

NASA Technical Reports Server (NTRS)

Kafatos, M.; Michalitsianos, A. G.

1984-01-01

The physical characteristics of symbiotic star systems are discussed, based on a review of recent observational data. A model of a symbiotic star system is presented which illustrates how a cool red-giant star is embedded in a nebula whose atoms are ionized by the energetic radiation from its hot compact companion. UV outbursts from symbiotic systems are explained by two principal models: an accretion-disk-outburst model which describes how material expelled from the tenuous envelope of the red giant forms an inwardly-spiralling disk around the hot companion, and a thermonuclear-outburst model in which the companion is specifically a white dwarf which superheats the material expelled from the red giant to the point where thermonuclear reactions occur and radiation is emitted. It is suspected that the evolutionary course of binary systems is predetermined by the initial mass and angular momentum of the gas cloud within which binary stars are born. Since red giants and Mira variables are thought to be stars with a mass of one or two solar mass, it is believed that the original cloud from which a symbiotic system is formed can consist of no more than a few solar masses of gas.

MAGNETAR GIANT FLARES AND THEIR PRECURSORS-FLUX ROPE ERUPTIONS WITH CURRENT SHEETS

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

Yu Cong; Huang Lei, E-mail: cyu@ynao.ac.cn, E-mail: muduri@shao.ac.cn

2013-07-10

We propose a catastrophic magnetospheric model for magnetar precursors and their successive giant flares. Axisymmetric models of the magnetosphere, which contain both a helically twisted flux rope and a current sheet, are established based on force-free field configurations. In this model, the helically twisted flux rope would lose its equilibrium and erupt abruptly in response to the slow and quasi-static variations at the ultra-strongly magnetized neutron star's surface. In a previous model without current sheets, only one critical point exists in the flux rope equilibrium curve. New features show up in the equilibrium curves for the flux rope when currentmore » sheets appear in the magnetosphere. The causal connection between the precursor and the giant flare, as well as the temporary re-entry of the quiescent state between the precursor and the giant flare, can be naturally explained. Magnetic energy would be released during the catastrophic state transitions. The detailed energetics of the model are also discussed. The current sheet created by the catastrophic loss of equilibrium of the flux rope provides an ideal place for magnetic reconnection. We point out the importance of magnetic reconnection for further enhancement of the energy release during eruptions.« less

Forsterite Shock Temperatures and Entropy: New Scaling Laws for Impact Melting and Vaporization

NASA Astrophysics Data System (ADS)

Davies, E.; Root, S.; Kraus, R. G.; Townsend, J. P.; Spaulding, D.; Stewart, S. T.; Jacobsen, S. B.; Fratanduono, D.; Millot, M. A.; Mattsson, T. R.; Hanshaw, H. L.

2017-12-01

The observed masses, radii and temperatures of thousands of extra-solar planets have challenged our theoretical understanding of planet formation and planetary structures. Planetary materials are subject to extreme pressures and temperatures during formation and within the present-day interiors of large bodies. Here, we focus on improving understanding of the physical properties of rocky planets for calculations of internal structure and the outcomes of giant impacts. We performed flyer plate impact experiments on forsterite [Mg2SiO4] on the Z-Machine at Sandia National Laboratory and decaying shock temperature measurements at the Omega EP laser at U. Rochester. At Z, planar, supported shock waves are generated in single crystal samples, permitting observation of both compressed and released states. Using available static and dynamic thermodynamic data, we calculate absolute entropy and heat capacity along the forsterite shock Hugoniot. Entropy and heat capacity on the Hugoniot are larger than previous estimates. Our data constrain the thermodynamic properties of forsterite liquid at high pressures and temperatures and the amount of melt and vapor produced during impact events. For an ambient pressure of 1 bar, shock-vaporization begins upon reaching the liquid region on the forsterite Hugoniot (about 200 GPa). Using hydrocode simulations of giant impacts between rocky planets with forsterite mantles and iron cores and the new experimentally-constrained forsterite shock entropy, we present a new scaling law for the fraction of mantle that is melted or vaporized by the initial shock wave. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525. Prepared by LLNL under Contract DE-AC52-07NA27344. Prepared by the Center for Frontiers in High Energy Density Science

Multifocal tenosynovial giant cell tumors in a child with Noonan syndrome.

PubMed

Meyers, Arthur B; Awomolo, Agboola O; Szabo, Sara

2017-03-01

Noonan syndrome is a genetic disorder with variable expression of distinctive facial features, webbed neck, chest deformity, short stature, cryptorchidism and congenital heart disease. The association of Noonan syndrome and giant cell granulomas of the mandible is widely reported. However, Noonan syndrome may also be associated with single or multifocal tenosynovial giant cell tumors, also referred to as pigmented villonodular synovitis. We report a child with Noonan syndrome, giant cell granulomas of the mandible and synovial and tenosynovial giant cell tumors involving multiple joints and tendon sheaths who was initially misdiagnosed with juvenile idiopathic arthritis. It is important for radiologists to be aware of the association of Noonan syndrome and multifocal giant cell lesions, which can range from the more commonly described giant cell granulomas of the mandible to isolated or multifocal intra- or extra-articular tenosynovial giant cell tumors or a combination of all of these lesions.

Giant polygons and mounds in the lowlands of Mars: signatures of an ancient ocean?

PubMed

Oehler, Dorothy Z; Allen, Carlton C

2012-06-01

This paper presents the hypothesis that the well-known giant polygons and bright mounds of the martian lowlands may be related to a common process-a process of fluid expulsion that results from burial of fine-grained sediments beneath a body of water. Specifically, we hypothesize that giant polygons and mounds in Chryse and Acidalia Planitiae are analogous to kilometer-scale polygons and mud volcanoes in terrestrial, marine basins and that the co-occurrence of masses of these features in Chryse and Acidalia may be the signature of sedimentary processes in an ancient martian ocean. We base this hypothesis on recent data from both Earth and Mars. On Earth, 3-D seismic data illustrate kilometer-scale polygons that may be analogous to the giant polygons on Mars. The terrestrial polygons form in fine-grained sediments that have been deposited and buried in passive-margin, marine settings. These polygons are thought to result from compaction/dewatering, and they are commonly associated with fluid expulsion features, such as mud volcanoes. On Mars, in Chryse and Acidalia Planitiae, orbital data demonstrate that giant polygons and mounds have overlapping spatial distributions. There, each set of features occurs within a geological setting that is seemingly analogous to that of the terrestrial, kilometer-scale polygons (broad basin of deposition, predicted fine-grained sediments, and lack of significant horizontal stress). Regionally, the martian polygons and mounds both show a correlation to elevation, as if their formation were related to past water levels. Although these observations are based on older data with incomplete coverage, a similar correlation to elevation has been established in one local area studied in detail with newer higher-resolution data. Further mapping with the latest data sets should more clearly elucidate the relationship(s) of the polygons and mounds to elevation over the entire Chryse-Acidalia region and thereby provide more insight into this hypothesis.

Chemical abundances and kinematics of 257 G-, K-type field giants. Setting a base for further analysis of giant-planet properties orbiting evolved stars

NASA Astrophysics Data System (ADS)

Adibekyan, V. Zh.; Benamati, L.; Santos, N. C.; Alves, S.; Lovis, C.; Udry, S.; Israelian, G.; Sousa, S. G.; Tsantaki, M.; Mortier, A.; Sozzetti, A.; De Medeiros, J. R.

2015-06-01

We performed a uniform and detailed abundance analysis of 12 refractory elements (Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Co, Sc, Mn, and V) for a sample of 257 G- and K-type evolved stars from the CORALIE planet search programme. To date, only one of these stars is known to harbour a planetary companion. We aimed to characterize this large sample of evolved stars in terms of chemical abundances and kinematics, thus setting a solid base for further analysis of planetary properties around giant stars. This sample, being homogeneously analysed, can be used as a comparison sample for other planet-related studies, as well as for different type of studies related to stellar and Galaxy astrophysics. The abundances of the chemical elements were determined using an local thermodynamic equilibrium (LTE) abundance analysis relative to the Sun, with the spectral synthesis code MOOG and a grid of Kurucz ATLAS9 atmospheres. To separate the Galactic stellar populations, both a purely kinematical approach and a chemical method were applied. We confirm the overabundance of Na in giant stars compared to the field FGK dwarfs. This enhancement might have a stellar evolutionary character, but departures from LTE may also produce a similar enhancement. Our chemical separation of stellar populations also suggests a `gap' in metallicity between the thick-disc and high-α metal-rich stars, as previously observed in dwarfs sample from HARPS. The present sample, as most of the giant star samples, also suffers from the B - V colour cut-off, which excludes low-log g stars with high metallicities, and high-log g star with low [Fe/H]. For future studies of planet occurrence dependence on stellar metallicity around these evolved stars, we suggest to use a subsample of stars in a `cut-rectangle' in the log g-[Fe/H] diagram to overcome the aforementioned issue.

Docetaxel-Loaded Nanoparticles Assembled from β-Cyclodextrin/Calixarene Giant Surfactants: Physicochemical Properties and Cytotoxic Effect in Prostate Cancer and Glioblastoma Cells.

PubMed

Gallego-Yerga, Laura; Posadas, Inmaculada; de la Torre, Cristina; Ruiz-Almansa, Jesús; Sansone, Francesco; Ortiz Mellet, Carmen; Casnati, Alessandro; García Fernández, José M; Ceña, Valentín

2017-01-01

Giant amphiphiles encompassing a hydrophilic β-cyclodextrin (βCD) component and a hydrophobic calix[4]arene (CA 4 ) module undergo self-assembly in aqueous media to afford core-shell nanospheres or nanocapsules, depending on the nanoprecipitation protocol, with high docetaxel (DTX) loading capacity. The blank and loaded nanoparticles have been fully characterized by dynamic light scattering (DLS), ζ-potential measurements and cryo-transmission electron microscopy (cryo-TEM). The data are compatible with the distribution of the drug between the nanoparticle core and the shell, where it is probably anchored by inclusion of the DTX aromatic moieties in βCD cavities. Indeed, the release kinetics profiles evidenced an initial fast release of the drug, which likely accounts for the fraction hosted on the surface, followed by a slow and sustained release rate, corresponding to diffusion of DTX in the core, which can be finely tuned by modification of the giant amphiphile chemical structure. The ability of the docetaxel-loaded nanoparticles to induce cellular death in different prostate (human LnCap and PC3) and glioblastoma (human U87 and rat C6) cells was also explored. Giant amphiphile-based DTX formulations surpassing or matching the antitumoral activity of the free DTX formulation were identified in all cases with no need to employ any organic co-solvent, thus overcoming the DTX water solubility problems. Moreover, the presence of the βCD shell at the surface of the assemblies is intended to impart stealth properties against serum proteins while permitting nanoparticle surface decoration by supramolecular approaches, paving the way for a new generation of molecularly well-defined antitumoral drug delivery systems with improved specificity and efficiency. Altogether, the results provide a proof of concept of the suitability of the approach based on βCD-CA 4 giant amphiphiles to access DTX carriers with tunable properties.

Influence of Stellar Multiplicity On Planet Formation. III. Adaptive Optics Imaging of Kepler Stars With Gas Giant Planets

NASA Astrophysics Data System (ADS)

Wang, Ji; Fischer, Debra A.; Horch, Elliott P.; Xie, Ji-Wei

2015-06-01

As hundreds of gas giant planets have been discovered, we study how these planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant planet formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color information and galactic stellar population statistics. We find evidence of suppressive planet formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate (MR) for planet host stars is {0}-0+5% within 20 AU. In comparison, the stellar MR is 18% ± 2% for the control sample, i.e., field stars in the solar neighborhood. The stellar MR for planet host stars is 34% ± 8% for separations between 20 and 200 AU, which is higher than the control sample at 12% ± 2%. Beyond 200 AU, stellar MRs are comparable between planet host stars and the control sample. We discuss the implications of the results on gas giant planet formation and evolution.

Modeling activity patterns of wildlife using time-series analysis.

PubMed

Zhang, Jindong; Hull, Vanessa; Ouyang, Zhiyun; He, Liang; Connor, Thomas; Yang, Hongbo; Huang, Jinyan; Zhou, Shiqiang; Zhang, Zejun; Zhou, Caiquan; Zhang, Hemin; Liu, Jianguo

2017-04-01

The study of wildlife activity patterns is an effective approach to understanding fundamental ecological and evolutionary processes. However, traditional statistical approaches used to conduct quantitative analysis have thus far had limited success in revealing underlying mechanisms driving activity patterns. Here, we combine wavelet analysis, a type of frequency-based time-series analysis, with high-resolution activity data from accelerometers embedded in GPS collars to explore the effects of internal states (e.g., pregnancy) and external factors (e.g., seasonal dynamics of resources and weather) on activity patterns of the endangered giant panda ( Ailuropoda melanoleuca ). Giant pandas exhibited higher frequency cycles during the winter when resources (e.g., water and forage) were relatively poor, as well as during spring, which includes the giant panda's mating season. During the summer and autumn when resources were abundant, pandas exhibited a regular activity pattern with activity peaks every 24 hr. A pregnant individual showed distinct differences in her activity pattern from other giant pandas for several months following parturition. These results indicate that animals adjust activity cycles to adapt to seasonal variation of the resources and unique physiological periods. Wavelet coherency analysis also verified the synchronization of giant panda activity level with air temperature and solar radiation at the 24-hr band. Our study also shows that wavelet analysis is an effective tool for analyzing high-resolution activity pattern data and its relationship to internal and external states, an approach that has the potential to inform wildlife conservation and management across species.

No Metallicity Correlation Associated with the Kepler Dichotomy

NASA Astrophysics Data System (ADS)

Munoz Romero, Carlos Eduardo; Kempton, Eliza

2018-01-01

NASA’s Kepler mission has discovered thousands of planetary systems, ∼ 20% of which are found to host multiple transiting planets. This relative paucity (compared to the high fraction of single transiting systems) is postulated to result from a distinction in the architecture between multi-transiting systems and those hosting a single transiting planet: a phenomenon usually referred to as the Kepler dichotomy. We investigate the hypothesis that external giant planets are the main cause behind the over-abundance of single- relative to multi-transiting systems, which would be signaled by higher metallicities in the former sample. To this end, we perform a statistical analysis on the stellar metallicity distribution with respect to planet multiplicity in the Kepler data. We perform our analysis on a variety of samples taken from a population of 1062 Kepler main sequence planetary hosts, using precisely determined metallicities from the California-Kepler survey. Contrary to some predictions, we do not find a significant difference between the stellar metallicities of the single- and multiple-transiting planet systems. However, we do find a 43% upper bound for systems with a single non-giant planet that could also host a hidden giant planet, based on metallicity considerations. While the presence of external giant planets might be one factor behind the Kepler dichotomy, our results also favor alternative explanations. We suggest that additional radial velocity and direct imaging measurements are necessary to constrain the presence of gas giants in systems with a single transiting planet.

Comprehensive analysis of the origin of giant jellyfish near Qinhuangdao in summer

NASA Astrophysics Data System (ADS)

Wu, Lingjuan; Wu, Xiaofen; Bai, Tao

2017-09-01

A massive bloom of the giant jellyfish Nemopilema nomurai occurred in waters offQinhuangdao, a port city in Hebei Province, in July 2013. However, jellyfish larvae were not found in this location during the previous winter and spring. To determine the possible origin of the giant jellyfish medusa in the Bohai Sea, we developed a backward particle-tracking model and a series of numerical simulations were conducted by using the hydrodynamic, three-dimensional Regional Ocean Modeling System (ROMS) results. The simulated results showed that passive particles, representing jellyfish medusae, released in surface waters at different dates during the summer had consistent trajectories. Particles released at the sea surface on August 1 and 15 could be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and the new Huanghe (Yellow) River estuary. Particles released on July 1 and 15 could also be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and only to Zhuangxi tide station. However, none of the particles released in the middle and bottom water layers could be traced back to those areas. Based on the results of the numerical simulations, the distribution characteristics of seafloor sediments, and observational data for giant jellyfish in the region, we suggest that waters between Feiyan Shoal and the new Huanghe River estuary are the likely origin of giant jellyfish observed near Qinhuangdao in summer.

Behavioral response of giant gartersnakes (Thamnophis gigas) to the relative availability of aquatic habitat on the landscape

USGS Publications Warehouse

Reyes, Gabriel A.; Halstead, Brian J.; Rose, Jonathan P.; Ersan, Julia S. M.; Jordan, Anna C.; Essert, Allison M.; Fouts, Kristen J.; Fulton, Alexandria M.; Gustafson, K. Benjamin; Wack, Raymond F.; Wylie, Glenn D.; Casazza, Michael L.

2017-11-16

Most extant giant gartersnake (Thamnophis gigas) populations persist in an agro-ecosystem dominated by rice, which serves as a surrogate to the expansive marshes lost to flood control projects and development of the Great Central Valley of California. Knowledge of how giant gartersnakes use the rice agricultural landscape, including how they respond to fallowing, idling, or crop rotations, would greatly benefit conservation of giant gartersnakes by informing more snake-friendly land and water management practices. We studied adult giant gartersnakes at 11 sites in the rice-growing regions of the Sacramento Valley during an extended drought in California to evaluate their response to differences in water availability at the site and individual levels. Although our study indicated that giant gartersnakes make little use of rice fields themselves, and avoid cultivated rice relative to its availability on the landscape, rice is a crucial component of the modern landscape for giant gartersnakes. Giant gartersnakes are strongly associated with the canals that supply water to and drain water from rice fields; these canals provide much more stable habitat than rice fields because they maintain water longer and support marsh-like conditions for most of the giant gartersnake active season. Nonetheless, our results suggest that maintaining canals without neighboring rice fields would be detrimental to giant gartersnake populations, with decreases in giant gartersnake survival rates associated with less rice production in the surrounding landscape. Increased productivity of prey populations, dispersion of potential predators across a larger landscape, and a more secure water supply are just some of the mechanisms by which rice fields might benefit giant gartersnakes in adjacent canals. Results indicate that identifying how rice benefits giant gartersnakes in canals and the extent to which the rice agro-ecosystem could provide these benefits when rice is fallowed would inform the use of water for other purposes without harm to giant gartersnakes. Our study also suggests that without such understanding, maintaining rice and associated canals in the Sacramento Valley is critical for the sustainability of giant gartersnake populations.

Giant Steps in Cefalù

NASA Astrophysics Data System (ADS)

Jeffery, David J.; Mazzali, Paolo A.

2007-08-01

Giant steps is a technique to accelerate Monte Carlo radiative transfer in optically-thick cells (which are isotropic and homogeneous in matter properties and into which astrophysical atmospheres are divided) by greatly reducing the number of Monte Carlo steps needed to propagate photon packets through such cells. In an optically-thick cell, packets starting from any point (which can be regarded a point source) well away from the cell wall act essentially as packets diffusing from the point source in an infinite, isotropic, homogeneous atmosphere. One can replace many ordinary Monte Carlo steps that a packet diffusing from the point source takes by a randomly directed giant step whose length is slightly less than the distance to the nearest cell wall point from the point source. The giant step is assigned a time duration equal to the time for the RMS radius for a burst of packets diffusing from the point source to have reached the giant step length. We call assigning giant-step time durations this way RMS-radius (RMSR) synchronization. Propagating packets by series of giant steps in giant-steps random walks in the interiors of optically-thick cells constitutes the technique of giant steps. Giant steps effectively replaces the exact diffusion treatment of ordinary Monte Carlo radiative transfer in optically-thick cells by an approximate diffusion treatment. In this paper, we describe the basic idea of giant steps and report demonstration giant-steps flux calculations for the grey atmosphere. Speed-up factors of order 100 are obtained relative to ordinary Monte Carlo radiative transfer. In practical applications, speed-up factors of order ten and perhaps more are possible. The speed-up factor is likely to be significantly application-dependent and there is a trade-off between speed-up and accuracy. This paper and past work suggest that giant-steps error can probably be kept to a few percent by using sufficiently large boundary-layer optical depths while still maintaining large speed-up factors. Thus, giant steps can be characterized as a moderate accuracy radiative transfer technique. For many applications, the loss of some accuracy may be a tolerable price to pay for the speed-ups gained by using giant steps.

Unraveling the origins of electromechanical response in mixed-phase Bismuth Ferrite

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

Vasudevan, Rama K; Okatan, M. B.; Liu, Y. Y.

The origin of giant electromechanical response in a mixed-phase rhombohedral-tetragonal BiFeO3 thin film is probed using sub-coercive scanning probe microscopy based multiple-harmonic measurements. Significant contributions to the strain arise from a second-order harmonic response localized at the phase boundaries. Strain and dissipation data, backed by thermodynamic calculations suggest that the source of the enhanced electromechanical response is the motion of phase boundaries. These findings elucidate the key role of labile phase boundaries, both natural and artificial, in achieving thin films with giant electromechanical properties.

Temperature dependence of giant magneto-resistance in PtMn- and Fe 2O 3-based specular spin valves

NASA Astrophysics Data System (ADS)

Kato, T.; Miyashita, K.; Iwata, S.; Tsunashima, S.; Sakakima, H.; Sugita, Y.; Kawawake, Y.

2002-02-01

Temperature dependence of the giant magneto-resistance (MR) was measured for spin valves with and without nano-oxide layer (NOL). In spin valves with NOL, the MR ratio increased more remarkably on lowering the temperature than in those without NOL. The temperature dependence of MR ratio and that of the resistivity were explained by using two-current model. The MR ratio enhanced with NOL is attributed to the increase of the mean free path of up-spin electrons.

Giant Rashba spin splitting in Bi bilayer induced by a 2D ferroelectric substrate

NASA Astrophysics Data System (ADS)

Zhu, Jianbao; Xiao, Di; Zhu, Wenguang

Based on density functional theory calculations, we discover that a Bi layer when placed on the top of a recently predicted 2D ferroelectric material with spontaneous out-of-plane electric polarization can exhibit giant Rashba-type spin splitting of over 200 meV, while the whole system still remains semiconducting. In addition, the magnitude of the Rashba spin splitting can be tuned by switching the diploe orientation of the 2D ferroelectric substrate. This finding provides a promising 2D material system for spintronics.

X-Ray Properties of Lensing-Selected Clusters

NASA Astrophysics Data System (ADS)

Paterno-Mahler, Rachel; Sharon, Keren; Bayliss, Matthew; McDonald, Michael; Gladders, Michael; Johnson, Traci; Dahle, Hakon; Rigby, Jane R.; Whitaker, Katherine E.; Florian, Michael; Wuyts, Eva

2017-08-01

I will present preliminary results from the Michigan Swift X-ray observations of clusters from the Sloan Giant Arcs Survey (SGAS). These clusters were lensing selected based on the presence of a giant arc visible from SDSS. I will characterize the morphology of the intracluster medium (ICM) of the clusters in the sample, and discuss the offset between the X-ray centroid, the mass centroid as determined by strong lensing analysis, and the BCG position. I will also present early-stage work on the scaling relation between the lensing mass and the X-ray luminosity.

To drink or grasp? How bullet ants ( Paraponera clavata) differentiate between sugars and proteins in liquids

NASA Astrophysics Data System (ADS)

Jandt, Jennifer; Larson, Hannah K.; Tellez, Peter; McGlynn, Terrence P.

2013-12-01

Flexibility in behavior can increase the likelihood that a forager may respond optimally in a fluctuating environment. Nevertheless, physiological or neuronal constraints may result in suboptimal responses to stimuli. We observed foraging workers of the giant tropical ant (also referred to as the "bullet ant"), Paraponera clavata, as they reacted to liquid solutions with varying concentrations of sugar and protein. We show that when protein/sucrose concentration is high, many bullet ants will often try to grasp at the droplet, rather than gather it by drinking. Because P. clavata actively hunt for prey, fixed action patterns and rapid responses to protein may be adaptively important, regardless of the medium in which it is presented. We conclude that, in P. clavata, food-handling decisions are made in response to the nutrient content of the food rather than the texture of the food. Further, we suggest that colonies that maintain a mixture of individuals with consistent fixed or flexible behavioral responses to food-handling decisions may be better adapted to fluctuating environmental conditions, and we propose future studies that could address this.

Advances in vitreoretinal surgery: macular hole repair and perfluorocarbon liquids.

PubMed

Monshizadeh, R; Haimovici, R

1995-01-01

1. Idiopathic macular hole was once thought to be an untreatable disorder. During the past several years, surgical techniques have evolved that allow for closure of the macular hole, with restoration of vision in many cases. 2. Perfluorocarbon liquids are an important class of compounds that are under investigation for use in vitreoretinal surgery. The use of these compounds facilitates the performance of intraocular surgical maneuvers in certain difficult-to-manage vitreoretinal disorders. These substances have a high specific gravity and are able to displace water within the eye, facilitating reattachment of the retina in certain types of retinal detachments such as those associated with proliferative vitreoretinopathy and giant retinal tears. PFCLs also aid in the removal of intravitreal lens fragments or foreign bodies and in the repositioning or removal of dislocated intraocular lenses. 3. Ophthalmic nurses and technicians can play an important role in initial screening for these patients. Detection of symptoms may lead to early diagnosis of idiopathic macular hole and subsequent treatment. Patient education emphasizing topics such as the importance of strict postoperative face-down head positioning may be critical for successful surgery.

Interaction of high density lipoprotein particles with membranes containing cholesterol.

PubMed

Sanchez, Susana A; Tricerri, Maria A; Gratton, Enrico

2007-08-01

In this study, free cholesterol (FC) efflux mediated by human HDL was investigated using fluorescence methodologies. The accessibility of FC to HDL may depend on whether it is located in regions rich in unsaturated phospholipids or in domains containing high levels of FC and sphingomyelin, known as "lipid rafts." Laurdan generalized polarization and two-photon microscopy were used to quantify FC removal from different pools in the bilayer of giant unilamellar vesicles (GUVs). GUVs made of POPC and FC were observed after incubation with reconstituted particles containing apolipoprotein A-I and POPC [78A diameter reconstituted high density lipoprotein (rHDL)]. Fluorescence correlation spectroscopy data show an increase in rHDL size during the incubation period. GUVs made of two "raft-like" mixtures [DOPC/DPPC/FC (1:1:1) and POPC/SPM/FC (6:1:1)] were used to model liquid-ordered/liquid-disordered phase coexistence. Through these experiments, we conclude that rHDL preferentially removes cholesterol from the more fluid phases. These data, and their extrapolation to in vivo systems, show the significant role that phase separation plays in the regulation of cholesterol homeostasis.

The Lithium Abundances of a Large Sample of Red Giants

NASA Astrophysics Data System (ADS)

Liu, Y. J.; Tan, K. F.; Wang, L.; Zhao, G.; Sato, Bun'ei; Takeda, Y.; Li, H. N.

2014-04-01

The lithium abundances for 378 G/K giants are derived with non-local thermodynamic equilibrium correction considered. Among these are 23 stars that host planetary systems. The lithium abundance is investigated, as a function of metallicity, effective temperature, and rotational velocity, as well as the impact of a giant planet on G/K giants. The results show that the lithium abundance is a function of metallicity and effective temperature. The lithium abundance has no correlation with rotational velocity at v sin i < 10 km s-1. Giants with planets present lower lithium abundance and slow rotational velocity (v sin i < 4 km s-1). Our sample includes three Li-rich G/K giants, 36 Li-normal stars, and 339 Li-depleted stars. The fraction of Li-rich stars in this sample agrees with the general rate of less than 1% in the literature, and the stars that show normal amounts of Li are supposed to possess the same abundance at the current interstellar medium. For the Li-depleted giants, Li-deficiency may have already taken place at the main sequence stage for many intermediate mass (1.5-5 M ⊙) G/K giants. Finally, we present the lithium abundance and kinematic parameters for an enlarged sample of 565 giants using a compilation of the literature, and confirm that the lithium abundance is a function of metallicity and effective temperature. With the enlarged sample, we investigate the differences between the lithium abundance in thin-/thick-disk giants, which indicate that the lithium abundance in thick-disk giants is more depleted than that in thin-disk giants.

Giant magneto-spin-Seebeck effect and magnon transfer torques in insulating spin valves

NASA Astrophysics Data System (ADS)

Cheng, Yihong; Chen, Kai; Zhang, Shufeng

2018-01-01

We theoretically study magnon transport in an insulating spin valve (ISV) made of an antiferromagnetic insulator sandwiched between two ferromagnetic insulator (FI) layers. In the conventional metal-based spin valve, the electron spins propagate between two metallic ferromagnetic layers, giving rise to giant magnetoresistance and spin transfer torque. Here, the incoherent magnons in the ISV serve as angular momentum carriers and are responsible for the angular momentum transport between two FI layers across the antiferromagnetic spacer. We predict two transport phenomena in the presence of the temperature gradient: a giant magneto-spin-Seebeck effect in which the output voltage signal is controlled by the relative orientation of the two FI layers and magnon transfer torque that can be used for switching the magnetization of the FI layers with a temperature gradient of the order of 0.1 Kelvin per nanometer.

Nanostructured giant magneto-impedance multilayers deposited onto flexible substrates for low pressure sensing

PubMed Central

2012-01-01

Nanostructured FeNi-based multilayers are very suitable for use as magnetic sensors using the giant magneto-impedance effect. New fields of application can be opened with these materials deposited onto flexible substrates. In this work, we compare the performance of samples prepared onto a rigid glass substrate and onto a cyclo olefin copolymer flexible one. Although a significant reduction of the field sensitivity is found due to the increased effect of the stresses generated during preparation, the results are still satisfactory for use as magnetic field sensors in special applications. Moreover, we take advantage of the flexible nature of the substrate to evaluate the pressure dependence of the giant magneto-impedance effect. Sensitivities up to 1 Ω/Pa are found for pressures in the range of 0 to 1 Pa, demostrating the suitability of these nanostructured materials deposited onto flexible substrates to build sensitive pressure sensors. PMID:22525096

John Ellard Gore: "Giant Suns and Miniature Stars"

NASA Astrophysics Data System (ADS)

Holberg, Jay B.

2007-12-01

The Irish amateur astronomer John Ellard Gore (1845-1910) was a founding member of the British Astronomical Association and a prolific author of popular astronomy between 1880 and 1910. He is perhaps best remembered for his books `The Visible Universe’ (1893), an English language translation of Camille Flammarion's `Popular Astronomy’ (1894) and his contributions to Agnes Clerk's `Astronomy’ (1898). I consider a little known investigation that Gore undertook into the question of stellar `sizes’ using binary stars. This led him to the realization of the existence of "Giant Suns” as well as "Miniature Stars” the latter included the sun. Gore also considered the existence of hyper-dense compact objects, now known as white dwarfs. Unfortunately Gore rejected the reality of the latter stellar types. Gore based his conclusions on a formula developed by fellow Irish astronomer W.H.S. Monck, who was reaching similar conclusions about Giant stars through the study of stellar motions.

The energy source of the most energetic giant outbursts in MS 0735 + 7421

NASA Astrophysics Data System (ADS)

Li, Shuang-Liang

2013-02-01

In this work, we investigate the power source of the most energetic giant outbursts in MS 0735 + 7421, which released ~ 1062 erg of energy. Due to the very high mean jet power in the cavities (P jet/L Edd ~ 0.02), we produce several jet formation models based on a relativistic thin disk model, i.e., general BP + BZ mechanisms (model A), Livio's (model B) and Meier's (model C) model, to explain the giant outbursts in AGNs. It is found that the energy provided by both model B and model C are inadequate for an initial black hole spin a 0 ~ 0.1, only model A can explain the most violent outbursts in MS 0735 + 7421. But if the initial black hole spin a 0 ~ 0.95, model B can also blow up the cavity. The final spin of the black hole is found to be very high in spite of the initial spin.

On the possibility of Earth-type habitable planets in the 55 Cancri system.

PubMed

von Bloh, W; Cuntz, M; Franck, S; Bounama, C

2003-01-01

We discuss the possibility of Earth-type planets in the planetary system of 55 Cancri, a nearby G8 V star, which is host to two, possibly three, giant planets. We argue that Earth-type planets around 55 Cancri are in principle possible. Several conditions are necessary. First, Earth-type planets must have formed despite the existence of the close-in giant planet(s). In addition, they must be orbitally stable in the region of habitability considering that the stellar habitable zone is relatively close to the star compared to the Sun because of 55 Cancri's low luminosity and may therefore be affected by the close-in giant planet(s). We estimate the likelihood of Earth-type planets around 55 Cancri based on the integrated system approach previously considered, which provides a way of assessing the long-term possibility of photosynthetic biomass production under geodynamic conditions.

The Expanding Family of Virophages.

PubMed

Bekliz, Meriem; Colson, Philippe; La Scola, Bernard

2016-11-23

Virophages replicate with giant viruses in the same eukaryotic cells. They are a major component of the specific mobilome of mimiviruses. Since their discovery in 2008, five other representatives have been isolated, 18 new genomes have been described, two of which being nearly completely sequenced, and they have been classified in a new viral family, Lavidaviridae . Virophages are small viruses with approximately 35-74 nm large icosahedral capsids and 17-29 kbp large double-stranded DNA genomes with 16-34 genes, among which a very small set is shared with giant viruses. Virophages have been isolated or detected in various locations and in a broad range of habitats worldwide, including the deep ocean and inland. Humans, therefore, could be commonly exposed to virophages, although currently limited evidence exists of their presence in humans based on serology and metagenomics. The distribution of virophages, the consequences of their infection and the interactions with their giant viral hosts within eukaryotic cells deserve further research.

Dual Control of Giant Field-like Spin Torque in Spin Filter Tunnel Junctions

PubMed Central

Tang, Y. -H.; Chu, F. -C.; Kioussis, Nicholas

2015-01-01

We predict a giant field-like spin torque, , in spin-filter (SF) barrier tunnel junctions in sharp contrast to existing junctions based on nonmagnetic passive barriers. We demonstrate that has linear bias behavior, is independent of the SF thickness, and has odd parity with respect to the SF’s exchange splitting. Thus, it can be selectively controlled via external bias or external magnetic field which gives rise to sign reversal of via magnetic field switching. The underlying mechanism is the interlayer exchange coupling between the noncollinear magnetizations of the SF and free ferromagnetic electrode via the nonmagnetic insulating (I) spacer giving rise to giant spin-dependent reflection at the SF/I interface. These findings suggest that the proposed field-like-spin-torque MRAM may provide promising dual functionalities for both ‘reading’ and ‘writing’ processes which require lower critical current densities and faster writing and reading speeds. PMID:26095146

CNO isotopes in red giant stars

NASA Technical Reports Server (NTRS)

Wannier, P. G.

1985-01-01

Observational data on CNO abundance ratios in red giants and the interstellar medium (ISM) are analyzed for the implications for the production and distribution of CNO nuclides. The data included isotope abundance measurements for the atmospheres and recent ejecta of cool giants, e.g., carbon stars, S-type stars, red supergiants and oxygen-rich giants beginning an ascent of the giant branch. The contribution of intermediate-mass stars to galactic nuclear evolution is discussed after comparing red giant abundances with ISM abundances, particularly the isotopes O-16, -17 and -18. The O-12/O-18 ratios of red giants are distinctly different from those in interstellar molecular clouds. The CNO values also vary widely from the values found in the solar system.

CNO isotopes in red giant stars

NASA Technical Reports Server (NTRS)

Wannier, P. G.

1985-01-01

The production and distribution of the CNO nuclides is discussed in light of observed abundance ratios in red giants and in the interstellar medium. Isotope abundances have been measured in the atmospheres and in the recent ejecta of cool giants, including carbon stars, S-type stars and red supergiants as well as in oxygen-rich giants making their first ascent of the giant branch. Several of the observations suggest revision of currently accepted nuclear cross-sections and of the mixing processes operating in giant envelopes. By comparing red giant abundances with high-quality observations of the interstellar medium, conclusions are reached about the contribution of intermediate-mass stars to galactic nuclear evolution. The three oxygen isotopes, O-16, -17 and -18, are particularly valuable for such comparison because they reflect three different stages of stellar nucleosynthesis. One remarkable result comes from observations of O-17/O-18 in several classes of red giant stars. The observed range of values for red giants excludes the entire range of values seen in interstellar molecular clouds. Furthermore, both the observations of stars and interstellar clouds exclude the isotopic ratio found in the solar system.

Vibration analysis and experiment of giant magnetostrictive force sensor

NASA Astrophysics Data System (ADS)

Zhu, Zhiwen; Liu, Fang; Zhu, Xingqiao; Wang, Haibo; Xu, Jia

2017-12-01

In this paper, a kind of giant magnetostrictive force sensor is proposed, ans its magneto-mechanical coupled model is developed. The relationship between output voltage of giant magnetostrictive force sensor and input excitation force is obtained. The phenomena of accuracy aggravation in high frequency and delay of giant magnetostrictive sensor are explained. The experimental results show that the model can describe the actual response of giant magnetostrictive force sensor. The new model of giant magnetostrictive sensor has simple form and is easy to be analyzed in theory, which is helpful to be applied in measuring and control fields.

Clival giant cell tumor - A rare case report and review of literature with respect to current line of management

PubMed Central

Patibandla, Mohana Rao; Thotakura, Amit Kumar; Rao, Marabathina Nageswara; Addagada, Gokul Chowdary; Nukavarapu, Manisha Chowdary; Panigrahi, Manas Kumar; Uppin, Shantiveer; Challa, Sundaram; Dandamudi, Srinivas

2017-01-01

Giant-cell tumor (GCT) involving the skull base is rare. Sphenoid bone is the most commonly involved bone followed by petrous temporal bone. Histopathology and radiological features of these lesions are similar to GCT involving bone elsewhere. Unlike other sites, skull base is not an ideal site for the radical surgery. Hence adjuvant treatment has pivotal role. Radiation therapy with intensity-modulated radiation therapy, stereotactic radiosurgery or chemotherapy with adriamycin are promising as described in some case reports. Bisphosphonates showed good control in local recurrence. In vitro studies with Zolendronate loaded bone cement and phase 2 trials of Denosumab showed hopeful results, may be useful in future. PMID:28413541

Investigation of giant magnetoconductance in organic devices based on hopping mechanism

NASA Astrophysics Data System (ADS)

Yang, F. J.; Qin, W.; Xie, S. J.

2014-04-01

We suggest a spin-dependent hopping mechanism which includes the effect of the external magnetic field as well as hyperfine interaction (HFI) to explain the observed giant magnetoconductance (MC) in non-magnetic organic devices. Based on the extended Marcus theory, we calculate the MC by using the master equation. It is found that a MC value as large as 91% is obtained under a low driving voltage. For suitable parameters, the theoretical results are in good agreement with the experimental data. Influences of the carrier density, HFI, and the carrier localization on the MC value are investigated. Especially, it is found that a low-dimensional structure of the organic materials is favorable to get a large MC value.

Investigation of giant magnetoconductance in organic devices based on hopping mechanism

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

Yang, F. J.; Qin, W.; Xie, S. J., E-mail: xsj@sdu.edu.cn

2014-04-14

We suggest a spin-dependent hopping mechanism which includes the effect of the external magnetic field as well as hyperfine interaction (HFI) to explain the observed giant magnetoconductance (MC) in non-magnetic organic devices. Based on the extended Marcus theory, we calculate the MC by using the master equation. It is found that a MC value as large as 91% is obtained under a low driving voltage. For suitable parameters, the theoretical results are in good agreement with the experimental data. Influences of the carrier density, HFI, and the carrier localization on the MC value are investigated. Especially, it is found thatmore » a low-dimensional structure of the organic materials is favorable to get a large MC value.« less

Kinematics and abundances of K giants in the nuclear bulge of the Galaxy

NASA Astrophysics Data System (ADS)

Rich, R. Michael

1990-10-01

Radial velocities have been determined for 53 K giants in Baade's window, which belong to the nuclear bulge population and have abundances derived from low resolution spectra. Additional radial velocities for an overlapping sample of 71 bulge K giants show the same dependence of velocity dispersion on abundance; in both samples, the lower velocity dispersion of the metal-rich giants is found to be significant at a level above 90 percent. Extant data support the hypothesis that both M giants and IRAS bulge sources follow steep density laws similar to that which has been predicted for the metal-rick K giants. The abundance distribution of 88 K giants in Baade's window is noted to be notably well fitted by the simple, 'closed box' model of chemical evolution.

Construction and analysis of a giant gartersnake (Thamnophis gigas) population projection model

USGS Publications Warehouse

Rose, Jonathan P.; Ersan, Julia S. M.; Wylie, Glenn D.; Casazza, Michael L.; Halstead, Brian J.

2018-03-19

The giant gartersnake (Thamnophis gigas) is a state and federally threatened species precinctive to California. The range of the giant gartersnake has contracted in the last century because its wetland habitat has been drained for agriculture and development. As a result of this habitat alteration, giant gartersnakes now largely persist in and near rice agriculture in the Sacramento Valley, because the system of canals that conveys water for rice growing approximates historical wetland habitat. Many aspects of the demography of giant gartersnakes are unknown, including how individuals grow throughout their life, how size influences reproduction, and how survival varies over time and among populations. We studied giant gartersnakes throughout the Sacramento Valley of California from 1995 to 2016 using capture-mark-recapture to study the growth, reproduction, and survival of this threatened species. We then use these data to construct an Integral Projection Model, and analyze this demographic model to understand which vital rates contribute most to the growth rate of giant gartersnake populations. We find that giant gartersnakes exhibit indeterminate growth; growth slows as individuals’ age. Fecundity, probability of reproduction, and survival all increase with size, although survival may decline for the largest female giant gartersnakes. The population growth rate of giant gartersnakes is most influenced by the survival and growth of large adult females, and the size at which 1 year old recruits enter the population. Our results indicate that management actions benefitting these influential demographic parameters will have the greatest positive effect on giant gartersnake population growth rates, and therefore population persistence. This study informs the conservation and management of giant gartersnakes and their habitat, and illustrates the effectiveness of hierarchical Bayesian models for the study of rare and elusive species.

The lithium abundances of a large sample of red giants

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

Liu, Y. J.; Tan, K. F.; Wang, L.

2014-04-20

The lithium abundances for 378 G/K giants are derived with non-local thermodynamic equilibrium correction considered. Among these are 23 stars that host planetary systems. The lithium abundance is investigated, as a function of metallicity, effective temperature, and rotational velocity, as well as the impact of a giant planet on G/K giants. The results show that the lithium abundance is a function of metallicity and effective temperature. The lithium abundance has no correlation with rotational velocity at v sin i < 10 km s{sup –1}. Giants with planets present lower lithium abundance and slow rotational velocity (v sin i < 4more » km s{sup –1}). Our sample includes three Li-rich G/K giants, 36 Li-normal stars, and 339 Li-depleted stars. The fraction of Li-rich stars in this sample agrees with the general rate of less than 1% in the literature, and the stars that show normal amounts of Li are supposed to possess the same abundance at the current interstellar medium. For the Li-depleted giants, Li-deficiency may have already taken place at the main sequence stage for many intermediate mass (1.5-5 M {sub ☉}) G/K giants. Finally, we present the lithium abundance and kinematic parameters for an enlarged sample of 565 giants using a compilation of the literature, and confirm that the lithium abundance is a function of metallicity and effective temperature. With the enlarged sample, we investigate the differences between the lithium abundance in thin-/thick-disk giants, which indicate that the lithium abundance in thick-disk giants is more depleted than that in thin-disk giants.« less

Metagenomic Study Suggests That the Gut Microbiota of the Giant Panda (Ailuropoda melanoleuca) May Not Be Specialized for Fiber Fermentation

PubMed Central

Guo, Wei; Mishra, Sudhanshu; Zhao, Jiangchao; Tang, Jingsi; Zeng, Bo; Kong, Fanli; Ning, Ruihong; Li, Miao; Zhang, Hengzhi; Zeng, Yutian; Tian, Yuanliangzi; Zhong, Yihang; Luo, Hongdi; Liu, Yunhan; Yang, Jiandong; Yang, Mingyao; Zhang, Mingwang; Li, Yan; Ni, Qingyong; Li, Caiwu; Wang, Chengdong; Li, Desheng; Zhang, Hemin; Zuo, Zhili; Li, Ying

2018-01-01

Bamboo-eating giant panda (Ailuropoda melanoleuca) is an enigmatic species, which possesses a carnivore-like short and simple gastrointestinal tract (GIT). Despite the remarkable studies on giant panda, its diet adaptability status continues to be a matter of debate. To resolve this puzzle, we investigated the functional potential of the giant panda gut microbiome using shotgun metagenomic sequencing of fecal samples. We also compared our data with similar data from other animal species representing herbivores, carnivores, and omnivores from current and earlier studies. We found that the giant panda hosts a bear-like gut microbiota distinct from those of herbivores indicated by the metabolic potential of the microbiome in the gut of giant pandas and other mammals. Furthermore, the relative abundance of genes involved in cellulose- and hemicellulose-digestion, and enrichment of enzymes associated with pathways of amino acid degradation and biosynthetic reactions in giant pandas echoed a carnivore-like microbiome. Most significantly, the enzyme assay of the giant panda's feces indicated the lowest cellulase and xylanase activity among major herbivores, shown by an in-vitro experimental assay of enzyme activity for cellulose and hemicellulose-degradation. All of our results consistently indicate that the giant panda is not specialized to digest cellulose and hemicellulose from its bamboo diet, making the giant panda a good mammalian model to study the unusual link between the gut microbiome and diet. The increased food intake of the giant pandas might be a strategy to compensate for the gut microbiome functions, highlighting a strong need of conservation of the native bamboo forest both in high- and low-altitude ranges to meet the great demand of bamboo diet of giant pandas. PMID:29503636

Metagenomic Study Suggests That the Gut Microbiota of the Giant Panda (Ailuropoda melanoleuca) May Not Be Specialized for Fiber Fermentation.

PubMed

Guo, Wei; Mishra, Sudhanshu; Zhao, Jiangchao; Tang, Jingsi; Zeng, Bo; Kong, Fanli; Ning, Ruihong; Li, Miao; Zhang, Hengzhi; Zeng, Yutian; Tian, Yuanliangzi; Zhong, Yihang; Luo, Hongdi; Liu, Yunhan; Yang, Jiandong; Yang, Mingyao; Zhang, Mingwang; Li, Yan; Ni, Qingyong; Li, Caiwu; Wang, Chengdong; Li, Desheng; Zhang, Hemin; Zuo, Zhili; Li, Ying

2018-01-01

Bamboo-eating giant panda ( Ailuropoda melanoleuca ) is an enigmatic species, which possesses a carnivore-like short and simple gastrointestinal tract (GIT). Despite the remarkable studies on giant panda, its diet adaptability status continues to be a matter of debate. To resolve this puzzle, we investigated the functional potential of the giant panda gut microbiome using shotgun metagenomic sequencing of fecal samples. We also compared our data with similar data from other animal species representing herbivores, carnivores, and omnivores from current and earlier studies. We found that the giant panda hosts a bear-like gut microbiota distinct from those of herbivores indicated by the metabolic potential of the microbiome in the gut of giant pandas and other mammals. Furthermore, the relative abundance of genes involved in cellulose- and hemicellulose-digestion, and enrichment of enzymes associated with pathways of amino acid degradation and biosynthetic reactions in giant pandas echoed a carnivore-like microbiome. Most significantly, the enzyme assay of the giant panda's feces indicated the lowest cellulase and xylanase activity among major herbivores, shown by an in-vitro experimental assay of enzyme activity for cellulose and hemicellulose-degradation. All of our results consistently indicate that the giant panda is not specialized to digest cellulose and hemicellulose from its bamboo diet, making the giant panda a good mammalian model to study the unusual link between the gut microbiome and diet. The increased food intake of the giant pandas might be a strategy to compensate for the gut microbiome functions, highlighting a strong need of conservation of the native bamboo forest both in high- and low-altitude ranges to meet the great demand of bamboo diet of giant pandas.

THE RADIO CONTINUUM STRUCTURE OF CENTAURUS A AT 1.4 GHz

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

Feain, I. J.; Cornwell, T. J.; Ekers, R. D.

2011-10-10

A 45 deg{sup 2} radio continuum imaging campaign of the nearest radio galaxy, Centaurus A, is reported. Using the Australia Telescope Compact Array and the Parkes 64 m radio telescope at 1.4 GHz, the spatial resolution of the resultant image is {approx}600 pc ({approx}50''), resolving the {approx}>500 kpc giant radio lobes with approximately five times better physical resolution compared to any previous image, and making this the most detailed radio continuum image of any radio galaxy to date. In this paper, we present these new data and discuss briefly some of the most interesting morphological features that we have discoveredmore » in the images. The two giant outer lobes are highly structured and considerably distinct. The southern part of the giant northern lobe naturally extends out from the northern middle lobe with uniformly north-streaming emission. The well known northern loop is resolved into a series of semi-regular shells with a spacing of approximately 25 kpc. The northern part of the giant northern lobe also contains identifiable filaments and partial ring structures. As seen in previous single-dish images at lower angular resolution, the giant southern lobe is not physically connected to the core at radio wavelengths. Almost the entirety of the giant southern lobe is resolved into a largely chaotic and mottled structure which appears considerably different (morphologically) to the diffuse regularity of the northern lobe. We report the discovery of a vertex and a vortex near the western boundary of the southern lobe, two striking, high surface brightness features that are named based on their morphology and not their dynamics (which are presently unknown). The vortex and vertex are modeled as reaccelerated lobe emission due to shocks from the active galactic nucleus itself or from the passage of a dwarf elliptical galaxy through the lobe. Preliminary polarimetric and spectral index studies support a plasma reacceleration model and could explain the origin of the Faraday rotation structure detected in the southern lobe. In addition, there are a series of low surface brightness wisps detected around the edges of both the giant lobes.« less

The HK-II Survey: Kinematics of Metal-Poor Stars in the Galaxy

NASA Astrophysics Data System (ADS)

Rhee, J.; Beers, T. C.

2003-12-01

The digitized HK-II survey (Rhee 2000, Ph.D. thesis, MSU) was originated as a follow-on to the HK-I survey of Beers and colleagues (e.g., Beers et al. 1992, AJ, 103, 1987). HK-I was based on visually-selected candidate metal-poor stars from objective-prism plates. Unfortunately, in the absence of color information, this selection technique introduced a rather severe temperature-related bias. As a result, the HK-I candidates do not include large numbers of metal-deficient giants. In HK-II, candidate metal-poor stars are quantitatively selected from digitized objective-prism spectra with JHK color information from the recently completeted 2MASS catalog. This approach eliminates much of the temperature bias. We have begun to survey candidate very metal-poor ([Fe/H] ≤ -2.0) giants from HK-II, over the magnitude range 11.0 ≤ B ≤ 16.0, covering some ˜7000 deg2 of intermediate to high Galactic-latitudes. Ongoing medium-resolution ( ˜ 1-2Å ) spectroscopic follow-up using NOAO observing facilities has allowed us to obtain, to date, some 1000 spectra (400, 450, and 150 spectra for red giants, subgiants near the main-sequence turnoff, and FHB/A stars, respectively) for the HK-II metal-poor star candidates. In particular, the detection rate of bona fide very metal-poor giants is about 45 %, which is quite encouraging. Most of the "mistakes" are slightly more metal-rich giants, with -2.0 < [Fe/H] < -1.0. Metallicities and radial velocities are determined from our spectroscopy, and proper motions for most of the program stars are obtained from the recently released UCAC2 astrometric survey catalog. Here we present an analysis of the full space motions for numerous metal-poor stars from the HK-II survey. A comparision of the chemical and kinematic properties between high- and low-halo populations (that is, giants vs. sub-giants) will aid us in understanding the formation history of the Milky Way. J.R. acknowledges partial support for this work by NASA through the AAS Small Research Grant Program. T.C.B. acknowledges partial support for this work from NSF grants AST 00-98508 and AST 00-98549.

Chromospheres of two red giants in NGC 6752

NASA Technical Reports Server (NTRS)

Dupree, A. K.; Hartmann, L.; Harper, G. M.; Jordan, Carole; Rodgers, A. W.

1990-01-01

Two red giant stars, A31 and A59, in the globular cluster NGC 6752 exhibit Mg II (2800 A) emission with surface fluxes comparable to those observed among metal-deficient halo field giants, and among low-activity Population I giants. Optical echelle spectra of these cluster giants reveal emission in the core of the Ca II K (3933.7 A) line, and in the wing of the H-alpha (6562.8 A) profile. Asymmetries exist both in the emission profiles and the line cores. These observations demonstrate unequivocally the existence of chromospheres among old halo population giants, and the presence of mass outflow in their atmospheres. Maintenance of a relatively constant level of chromospheric activity on the red giant branch contrasts with the decay of magnetic dynamo activity exhibited by dwarf stars and younger giants. A purely hydrodynamic phenomenon may be responsible for heating the outer atmospheres of these stars, enhancing chromospheric emission, thus extending the atmospheres and facilitating mass loss.

Fatal canine distemper virus infection of giant pandas in China

PubMed Central

Feng, Na; Yu, Yicong; Wang, Tiecheng; Wilker, Peter; Wang, Jianzhong; Li, Yuanguo; Sun, Zhe; Gao, Yuwei; Xia, Xianzhu

2016-01-01

We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species. PMID:27310722

Fatal canine distemper virus infection of giant pandas in China.

PubMed

Feng, Na; Yu, Yicong; Wang, Tiecheng; Wilker, Peter; Wang, Jianzhong; Li, Yuanguo; Sun, Zhe; Gao, Yuwei; Xia, Xianzhu

2016-06-16

We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species.

Giant Polarization and High Temperature Monoclinic Phase in a Lead-Free Perovskite of Bi(Zn 0.5Ti 0.5)O 3-BiFeO 3

DOE PAGES

Pan, Zhao; Chen, Jun; Yu, Runze; ...

2016-09-15

Lead-free piezoelectrics have attracted increasing attention due to the awareness of lead toxicity to the environment. Here, a new Bi-based lead-free perovskite of (1-x)Bi(Zn 0.5Ti 0.5)O 3-xBiFeO 3 has been synthesized via high-pressure and high-temperature method. It exhibits interest-ing properties of giant polarization, morphotropic phase boundary (MPB), and monoclinic phase. In particular, large tetragonality ( c/a = 1.228) and giant spontaneous polariza-tion of 110 μC/cm 2 has been obtained in 0.6Bi(Zn 0.5Ti 0.5)O 3-0.4BiFeO 3, which is much higher than most available lead-free materials and conventional Pb(Zr,Ti)O 3. MPB is clearly identified to be constituted by tetragonal and monoclinic phasesmore » at x = 0.5. Notably, a single monoclinic phase has been observed at x = 0.6, which exhibits an intriguing high temperature property. In conclusion, the present results are helpful to explore new lead-free MPB systems in bismuth-based compounds.« less

Characterization of the gut microbiota in the red panda (Ailurus fulgens).

PubMed

Kong, Fanli; Zhao, Jiangchao; Han, Shushu; Zeng, Bo; Yang, Jiandong; Si, Xiaohui; Yang, Benqing; Yang, Mingyao; Xu, Huailiang; Li, Ying

2014-01-01

The red panda is the only living species of the genus Ailurus. Like giant pandas, red pandas are also highly specialized to feed mainly on highly fibrous bamboo. Although several studies have focused on the gut microbiota in the giant panda, little is known about the gut microbiota of the red panda. In this study, we characterized the fecal microbiota from both wild (n = 16) and captive (n = 6) red pandas using a pyrosequecing based approach targeting the V1-V3 hypervariable regions of the 16S rRNA gene. Distinct bacterial communities were observed between the two groups based on both membership and structure. Wild red pandas maintained significantly higher community diversity, richness and evenness than captive red pandas, the communities of which were skewed and dominated by taxa associated with Firmicutes. Phylogenetic analysis of the top 50 OTUs revealed that 10 of them were related to known cellulose degraders. To the best of our knowledge, this is the first study of the gut microbiota of the red panda. Our data suggest that, similar to the giant panda, the gut microbiota in the red panda might also play important roles in the digestion of bamboo.

Development of a Novel Guided Wave Generation System Using a Giant Magnetostrictive Actuator for Nondestructive Evaluation

PubMed Central

Luo, Mingzhang; Li, Weijie; Wang, Junming; Chen, Xuemin; Song, Gangbing

2018-01-01

As a common approach to nondestructive testing and evaluation, guided wave-based methods have attracted much attention because of their wide detection range and high detection efficiency. It is highly desirable to develop a portable guided wave testing system with high actuating energy and variable frequency. In this paper, a novel giant magnetostrictive actuator with high actuation power is designed and implemented, based on the giant magnetostrictive (GMS) effect. The novel GMS actuator design involves a conical energy-focusing head that can focus the amplified mechanical energy generated by the GMS actuator. This design enables the generation of stress waves with high energy, and the focusing of the generated stress waves on the test object. The guided wave generation system enables two kinds of output modes: the coded pulse signal and the sweep signal. The functionality and the advantages of the developed system are validated through laboratory testing in the quality assessment of rock bolt-reinforced structures. In addition, the developed GMS actuator and the supporting system are successfully implemented and applied in field tests. The device can also be used in other nondestructive testing and evaluation applications that require high-power stress wave generation. PMID:29510540

Characterization of the Gut Microbiota in the Red Panda (Ailurus fulgens)

PubMed Central

Han, Shushu; Zeng, Bo; Yang, Jiandong; Si, Xiaohui; Yang, Benqing; Yang, Mingyao; Xu, Huailiang; Li, Ying

2014-01-01

The red panda is the only living species of the genus Ailurus. Like giant pandas, red pandas are also highly specialized to feed mainly on highly fibrous bamboo. Although several studies have focused on the gut microbiota in the giant panda, little is known about the gut microbiota of the red panda. In this study, we characterized the fecal microbiota from both wild (n = 16) and captive (n = 6) red pandas using a pyrosequecing based approach targeting the V1-V3 hypervariable regions of the 16S rRNA gene. Distinct bacterial communities were observed between the two groups based on both membership and structure. Wild red pandas maintained significantly higher community diversity, richness and evenness than captive red pandas, the communities of which were skewed and dominated by taxa associated with Firmicutes. Phylogenetic analysis of the top 50 OTUs revealed that 10 of them were related to known cellulose degraders. To the best of our knowledge, this is the first study of the gut microbiota of the red panda. Our data suggest that, similar to the giant panda, the gut microbiota in the red panda might also play important roles in the digestion of bamboo. PMID:24498390

Development of a Novel Guided Wave Generation System Using a Giant Magnetostrictive Actuator for Nondestructive Evaluation.

PubMed

Luo, Mingzhang; Li, Weijie; Wang, Junming; Wang, Ning; Chen, Xuemin; Song, Gangbing

2018-03-04

As a common approach to nondestructive testing and evaluation, guided wave-based methods have attracted much attention because of their wide detection range and high detection efficiency. It is highly desirable to develop a portable guided wave testing system with high actuating energy and variable frequency. In this paper, a novel giant magnetostrictive actuator with high actuation power is designed and implemented, based on the giant magnetostrictive (GMS) effect. The novel GMS actuator design involves a conical energy-focusing head that can focus the amplified mechanical energy generated by the GMS actuator. This design enables the generation of stress waves with high energy, and the focusing of the generated stress waves on the test object. The guided wave generation system enables two kinds of output modes: the coded pulse signal and the sweep signal. The functionality and the advantages of the developed system are validated through laboratory testing in the quality assessment of rock bolt-reinforced structures. In addition, the developed GMS actuator and the supporting system are successfully implemented and applied in field tests. The device can also be used in other nondestructive testing and evaluation applications that require high-power stress wave generation.

Cretaceous origin of giant rhinoceros beetles (Dynastini; Coleoptera) and correlation of their evolution with the Pangean breakup.

PubMed

Jin, Haofei; Yonezawa, Takahiro; Zhong, Yang; Kishino, Hirohisa; Hasegawa, Masami

2017-03-17

The giant rhinoceros beetles (Dynastini, Scarabaeidae, Coleoptera) are distributed in tropical and temperate regions in Asia, America and Africa. Recent molecular phylogenetic studies have revealed that the giant rhinoceros beetles can be divided into three clades representing Asia, America and Africa. Although a correlation between their evolution and the continental drift during the Pangean breakup was suggested, there is no accurate divergence time estimation among the three clades based on molecular data. Moreover, there is a long chronological gap between the timing of the Pangean breakup (Cretaceous: 110-148 Ma) and the emergence of the oldest fossil record (Oligocene: 33 Ma). In this study, we estimated their divergence times based on molecular data, using several combinations of fossil calibration sets, and obtained robust estimates. The inter-continental divergence events among the clades were estimated to have occurred about 99 Ma (Asian clade and others) and 78 Ma (American clade and African clade), both of which are after the Pangean breakup. These estimates suggest their inter-continental divergences occurred by overseas sweepstakes dispersal, rather than by vicariances of the population caused by the Pangean breakup.

New asteroseismic scaling relations based on the Hayashi track relation applied to red giant branch stars in NGC 6791 and NGC 6819

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

Wu, T.; Li, Y.; Hekker, S., E-mail: wutao@ynao.ac.cn, E-mail: ly@ynao.ac.cn, E-mail: hekker@mps.mpg.de

2014-01-20

Stellar mass M, radius R, and gravity g are important basic parameters in stellar physics. Accurate values for these parameters can be obtained from the gravitational interaction between stars in multiple systems or from asteroseismology. Stars in a cluster are thought to be formed coevally from the same interstellar cloud of gas and dust. The cluster members are therefore expected to have some properties in common. These common properties strengthen our ability to constrain stellar models and asteroseismically derived M, R, and g when tested against an ensemble of cluster stars. Here we derive new scaling relations based on amore » relation for stars on the Hayashi track (√(T{sub eff})∼g{sup p}R{sup q}) to determine the masses and metallicities of red giant branch stars in open clusters NGC 6791 and NGC 6819 from the global oscillation parameters Δν (the large frequency separation) and ν{sub max} (frequency of maximum oscillation power). The Δν and ν{sub max} values are derived from Kepler observations. From the analysis of these new relations we derive: (1) direct observational evidence that the masses of red giant branch stars in a cluster are the same within their uncertainties, (2) new methods to derive M and z of the cluster in a self-consistent way from Δν and ν{sub max}, with lower intrinsic uncertainties, and (3) the mass dependence in the Δν - ν{sub max} relation for red giant branch stars.« less

The Legacy of Arsenic Contamination from Giant Mine, Northern Canada: An Assessment of Impacts Based on Lake Water and Lake Sediment Core Analysis

NASA Astrophysics Data System (ADS)

Blais, J. M.; Korosi, J.

2016-12-01

The Giant Mine, which operated between 1948 and 2004 and located near the City of Yellowknife (Northwest Territories, Canada), has left a legacy of arsenic, antimony, and mercury contamination extending to the present day. Over 20,000 tonnes of arsenic trioxide dust was released from roaster stack emissions during its first 10 years of operations, leading to a significant contamination of the surrounding landscape. Here we present a summary of impacts by the recent contamination from Giant Mine on the surrounding region. A survey we conducted of 25 lakes of the region in 2010 revealed that most lake water within a 15 km radius of the roaster stack had arsenic concentrations in water > 10 mg/L, the standard for drinking water, with concentrations declining exponentially with increasing distance from the roaster stack. Sediment cores from lakes were collected near the Giant Mine roaster stack and radiometrically dated by 137Cs and excess 210Pb. Arsenic concentrations in these sediments increased by 1700% during the 1950s and 60s, consistent with the history of arsenic releases from roaster emissions. Correspondingly, pelagic diatoms and cladocerans were extirpated from one lake during this period, based on microfossil analysis of lake sediment deposits. Sediment core analysis further showed that this lake ecosystem has not recovered, even ten years after closure of the mine. Likely causes for the lack of recent recovery are explored with the use of sediment toxicity bioassays, using a novel paleo-ecotoxicological approach of using toxicity assessments of radiometrically dated lake sediment horizons.

A simulation of small to giant Antarctic iceberg evolution: Differential impact on climatology estimates

NASA Astrophysics Data System (ADS)

Rackow, Thomas; Wesche, Christine; Timmermann, Ralph; Hellmer, Hartmut H.; Juricke, Stephan; Jung, Thomas

2017-04-01

We present a simulation of Antarctic iceberg drift and melting that includes small, medium-sized, and giant tabular icebergs with a realistic size distribution. For the first time, an iceberg model is initialized with a set of nearly 7000 observed iceberg positions and sizes around Antarctica. The study highlights the necessity to account for larger and giant icebergs in order to obtain accurate melt climatologies. We simulate drift and lateral melt using iceberg-draft averaged ocean currents, temperature, and salinity. A new basal melting scheme, originally applied in ice shelf melting studies, uses in situ temperature, salinity, and relative velocities at an iceberg's bottom. Climatology estimates of Antarctic iceberg melting based on simulations of small (≤2.2 km), "small-to-medium-sized" (≤10 km), and small-to-giant icebergs (including icebergs >10 km) exhibit differential characteristics: successive inclusion of larger icebergs leads to a reduced seasonality of the iceberg meltwater flux and a shift of the mass input to the area north of 58°S, while less meltwater is released into the coastal areas. This suggests that estimates of meltwater input solely based on the simulation of small icebergs introduce a systematic meridional bias; they underestimate the northward mass transport and are, thus, closer to the rather crude treatment of iceberg melting as coastal runoff in models without an interactive iceberg model. Future ocean simulations will benefit from the improved meridional distribution of iceberg melt, especially in climate change scenarios where the impact of iceberg melt is likely to increase due to increased calving from the Antarctic ice sheet.

A simulation of small to giant Antarctic iceberg evolution: differential impact on climatology estimates

NASA Astrophysics Data System (ADS)

Rackow, Thomas; Wesche, Christine; Timmermann, Ralph; Hellmer, Hartmut H.; Juricke, Stephan; Jung, Thomas

2017-04-01

We present a simulation of Antarctic iceberg drift and melting that includes small (<2.2 km), medium-sized, and giant tabular icebergs with lengths of more than 10km. The model is initialized with a realistic size distribution obtained from satellite observations. Our study highlights the necessity to account for larger and giant icebergs in order to obtain accurate melt climatologies. Taking iceberg modeling a step further, we simulate drift and melting using iceberg-draft averaged ocean currents, temperature, and salinity. A new basal melting scheme, originally applied in ice shelf melting studies, uses in situ temperature, salinity, and relative velocities at an iceberg's keel. The climatology estimates of Antarctic iceberg melting based on simulations of small, 'small-to-medium'-sized, and small-to-giant icebergs (including icebergs > 10km) exhibit differential characteristics: successive inclusion of larger icebergs leads to a reduced seasonality of the iceberg meltwater flux and a shift of the mass input to the area north of 58°S, while less meltwater is released into the coastal areas. This suggests that estimates of meltwater input solely based on the simulation of small icebergs introduce a systematic meridional bias; they underestimate the northward mass transport and are, thus, closer to the rather crude treatment of iceberg melting as coastal runoff in models without an interactive iceberg model. Future ocean simulations will benefit from the improved meridional distribution of iceberg melt, especially in climate change scenarios where the impact of iceberg melt is likely to increase due to increased calving from the Antarctic ice sheet.

ASTEROSEISMIC-BASED ESTIMATION OF THE SURFACE GRAVITY FOR THE LAMOST GIANT STARS

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

Liu, Chao; Wu, Yue; Deng, Li-Cai

2015-07-01

Asteroseismology is one of the most accurate approaches to estimate the surface gravity of a star. However, most of the data from the current spectroscopic surveys do not have asteroseismic measurements, which is very expensive and time consuming. In order to improve the spectroscopic surface gravity estimates for a large amount of survey data with the help of the small subset of the data with seismic measurements, we set up a support vector regression (SVR) model for the estimation of the surface gravity supervised by 1374 Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) giant stars with Kepler seismic surfacemore » gravity. The new approach can reduce the uncertainty of the estimates down to about 0.1 dex, which is better than the LAMOST pipeline by at least a factor of 2, for the spectra with signal-to-noise ratio higher than 20. Compared with the log g estimated from the LAMOST pipeline, the revised log g values provide a significantly improved match to the expected distribution of red clump and red giant branch stars from stellar isochrones. Moreover, even the red bump stars, which extend to only about 0.1 dex in log g, can be discriminated from the new estimated surface gravity. The method is then applied to about 350,000 LAMOST metal-rich giant stars to provide improved surface gravity estimates. In general, the uncertainty of the distance estimate based on the SVR surface gravity can be reduced to about 12% for the LAMOST data.« less

The VLT-FLAMES Tarantula Survey . XXIV. Stellar properties of the O-type giants and supergiants in 30 Doradus

NASA Astrophysics Data System (ADS)

Ramírez-Agudelo, O. H.; Sana, H.; de Koter, A.; Tramper, F.; Grin, N. J.; Schneider, F. R. N.; Langer, N.; Puls, J.; Markova, N.; Bestenlehner, J. M.; Castro, N.; Crowther, P. A.; Evans, C. J.; García, M.; Gräfener, G.; Herrero, A.; van Kempen, B.; Lennon, D. J.; Maíz Apellániz, J.; Najarro, F.; Sabín-Sanjulián, C.; Simón-Díaz, S.; Taylor, W. D.; Vink, J. S.

2017-04-01

Context. The Tarantula region in the Large Magellanic Cloud (LMC) contains the richest population of spatially resolved massive O-type stars known so far. This unmatched sample offers an opportunity to test models describing their main-sequence evolution and mass-loss properties. Aims: Using ground-based optical spectroscopy obtained in the framework of the VLT-FLAMES Tarantula Survey (VFTS), we aim to determine stellar, photospheric and wind properties of 72 presumably single O-type giants, bright giants and supergiants and to confront them with predictions of stellar evolution and of line-driven mass-loss theories. Methods: We apply an automated method for quantitative spectroscopic analysis of O stars combining the non-LTE stellar atmosphere model fastwind with the genetic fitting algorithm pikaia to determine the following stellar properties: effective temperature, surface gravity, mass-loss rate, helium abundance, and projected rotational velocity. The latter has been constrained without taking into account the contribution from macro-turbulent motions to the line broadening. Results: We present empirical effective temperature versus spectral subtype calibrations at LMC-metallicity for giants and supergiants. The calibration for giants shows a +1kK offset compared to similar Galactic calibrations; a shift of the same magnitude has been reported for dwarfs. The supergiant calibrations, though only based on a handful of stars, do not seem to indicate such an offset. The presence of a strong upturn at spectral type O3 and earlier can also not be confirmed by our data. In the spectroscopic and classical Hertzsprung-Russell diagrams, our sample O stars are found to occupy the region predicted to be the core hydrogen-burning phase by state-of-the-art models. For stars initially more massive than approximately 60 M⊙, the giant phase already appears relatively early on in the evolution; the supergiant phase develops later. Bright giants, however, are not systematically positioned between giants and supergiants at Minit ≳ 25 M⊙. At masses below 60 M⊙, the dwarf phase clearly precedes the giant and supergiant phases; however this behavior seems to break down at Minit ≲ 18 M⊙. Here, stars classified as late O III and II stars occupy the region where O9.5-9.7 V stars are expected, but where few such late O V stars are actually seen. Though we can not exclude that these stars represent a physically distinct group, this behavior may reflect an intricacy in the luminosity classification at late O spectral subtype. Indeed, on the basis of a secondary classification criterion, the relative strength of Si iv to He I absorption lines, these stars would have been assigned a luminosity class IV or V. Except for five stars, the helium abundance of our sample stars is in agreement with the initial LMC composition. This outcome is independent of their projected spin rates. The aforementioned five stars present moderate projected rotational velocities (I.e., νesini < 200kms-1) and hence do not agree with current predictions of rotational mixing in main-sequence stars. They may potentially reveal other physics not included in the models such as binary-interaction effects. Adopting theoretical results for the wind velocity law, we find modified wind momenta for LMC stars that are 0.3 dex higher than earlier results. For stars brighter than 105 L⊙, that is, in the regime of strong stellar winds, the measured (unclumped) mass-loss rates could be considered to be in agreement with line-driven wind predictions if the clump volume filling factors were fV 1/8 to 1/6. Based on observations collected at the European Southern Observatory under program ID 182.D-0222.Tables C.1-C.5 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A81

Mismatch between the eye and the optic lobe in the giant squid.

PubMed

Liu, Yung-Chieh; Liu, Tsung-Han; Yu, Chun-Chieh; Su, Chia-Hao; Chiao, Chuan-Chin

2017-07-01

Giant squids ( Architeuthis ) are a legendary species among the cephalopods. They live in the deep sea and are well known for their enormous body and giant eyes. It has been suggested that their giant eyes are not adapted for the detection of either mates or prey at distance, but rather are best suited for monitoring very large predators, such as sperm whales, at distances exceeding 120 m and at a depth below 600 m (Nilsson et al. 2012 Curr. Biol. 22 , 683-688. (doi:10.1016/j.cub.2012.02.031)). However, it is not clear how the brain of giant squids processes visual information. In this study, the optic lobe of a giant squid ( Architeuthis dux , male, mantle length 89 cm), which was caught by local fishermen off the northeastern coast of Taiwan, was scanned using high-resolution magnetic resonance imaging in order to examine its internal structure. It was evident that the volume ratio of the optic lobe to the eye in the giant squid is much smaller than that in the oval squid ( Sepioteuthis lessoniana ) and the cuttlefish ( Sepia pharaonis ). Furthermore, the cell density in the cortex of the optic lobe is significantly higher in the giant squid than in oval squids and cuttlefish, with the relative thickness of the cortex being much larger in Architeuthis optic lobe than in cuttlefish. This indicates that the relative size of the medulla of the optic lobe in the giant squid is disproportionally smaller compared with these two cephalopod species. This morphological study of the giant squid brain, though limited only to the optic lobe, provides the first evidence to support that the optic lobe cortex, the visual information processing area in cephalopods, is well developed in the giant squid. In comparison, the optic lobe medulla, the visuomotor integration centre in cephalopods, is much less developed in the giant squid than other species. This finding suggests that, despite the giant eye and a full-fledged cortex within the optic lobe, the brain of giant squids has not evolved proportionally in terms of performing complex tasks compared with shallow-water cephalopod species.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Praxair trucks carrying their loads of liquid oxygen, or LO2, are on their way to Launch Pad 39B at NASA's Kennedy Space Center in Florida. The trucks will offload LO2 slowly into a giant storage sphere located at the northwest corner of the pad to gradually chill it down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

NASA Launch Director Charlie Blackwell-Thompson, at left, arrives at Launch Pad 39B at NASA's Kennedy Space Center in Florida, to observe the first major tanking operation of liquid oxygen, or LO2, into the giant storage sphere at the northwest corner of the pad to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. During the operation, several Praxair trucks will slowly offload LO2 to gradually chill down the sphere from normal temperature to about negative 298 degrees Fahrenheit. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

A large plume of mist or vapor is visible as a Praxair truck slowly transfers its load of liquid oxygen, or LO2, into a giant storage sphere at the northwest corner of Launch Pad 39B at NASA's Kennedy Space Center in Florida. The sphere will gradually be chilled down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

One of several Praxair trucks carrying its load of liquid oxygen, or LO2, is in route to Launch Pad 39B at NASA's Kennedy Space Center in Florida. The truck will offload LO2 slowly into a giant storage sphere located at the northwest corner of the pad to gradually chill it down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Several Praxair trucks carrying their loads of liquid oxygen, or LO2, have arrived at Launch Pad 39B at NASA's Kennedy Space Center in Florida. The trucks will offload LO2 slowly into a giant storage sphere located at the northwest corner of the pad to gradually chill it down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Deep learning classification in asteroseismology

NASA Astrophysics Data System (ADS)

Hon, Marc; Stello, Dennis; Yu, Jie

2017-08-01

In the power spectra of oscillating red giants, there are visually distinct features defining stars ascending the red giant branch from those that have commenced helium core burning. We train a 1D convolutional neural network by supervised learning to automatically learn these visual features from images of folded oscillation spectra. By training and testing on Kepler red giants, we achieve an accuracy of up to 99 per cent in separating helium-burning red giants from those ascending the red giant branch. The convolutional neural network additionally shows capability in accurately predicting the evolutionary states of 5379 previously unclassified Kepler red giants, by which we now have greatly increased the number of classified stars.

Sodium in weak G-band giants

NASA Technical Reports Server (NTRS)

Drake, Jeremy J.; Lambert, David L.

1994-01-01

Sodium abundances have been determined for eight weak G-band giants whose atmospheres are greatly enriched with products of the CN-cycling H-burning reactions. Systematic errors are minimized by comparing the weak G-band giants to a sample of similar but normal giants. If, further, Ca is selected as a reference element, model atmosphere-related errors should largely be removed. For the weak-G-band stars (Na/Ca) = 0.16 +/- 0.01, which is just possibly greater than the result (Na/Ca) = 0.10 /- 0.03 from the normal giants. This result demonstrates that the atmospheres of the weak G-band giants are not seriously contaminated with products of ON cycling.

Evolutionary dynamics of giant viruses and their virophages.

PubMed

Wodarz, Dominik

2013-07-01

Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested.

Evolutionary dynamics of giant viruses and their virophages

PubMed Central

Wodarz, Dominik

2013-01-01

Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested. PMID:23919155

ORIGIN OF LITHIUM ENRICHMENT IN K GIANTS

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

Kumar, Yerra Bharat; Reddy, Bacham E.; Lambert, David L.

In this Letter, we report on a low-resolution spectroscopic survey for Li-rich K giants among 2000 low-mass (M {<=} 3 M{sub sun}) giants spanning the luminosity range from below to above the luminosity of the clump. Fifteen new Li-rich giants including four super Li-rich K giants (log {epsilon}(Li) {>=}3.2) were discovered. A significant finding is that there is a concentration of Li-rich K giants at the luminosity of the clump or red horizontal branch. This new finding is partly a consequence of the fact that our low-resolution survey is the first large survey to include giants well below and abovemore » the red giant branch (RGB) bump and clump locations in the H-R diagram. Origin of the lithium enrichment may be plausibly attributed to the conversion of {sup 3}He via {sup 7}Be to {sup 7}Li by the Cameron-Fowler mechanism but the location for the onset of the conversion is uncertain. Two possible opportunities to effect this conversion are discussed: the bump in the first ascent of the RGB and the He-core flash at the tip of the RGB. The finite luminosity spread of the Li-rich giants serves to reject the idea that Li enhancement is, in general, a consequence of a giant swallowing a large planet.« less

Revealing the microstructure of the giant component in random graph ensembles

NASA Astrophysics Data System (ADS)

Tishby, Ido; Biham, Ofer; Katzav, Eytan; Kühn, Reimer

2018-04-01

The microstructure of the giant component of the Erdős-Rényi network and other configuration model networks is analyzed using generating function methods. While configuration model networks are uncorrelated, the giant component exhibits a degree distribution which is different from the overall degree distribution of the network and includes degree-degree correlations of all orders. We present exact analytical results for the degree distributions as well as higher-order degree-degree correlations on the giant components of configuration model networks. We show that the degree-degree correlations are essential for the integrity of the giant component, in the sense that the degree distribution alone cannot guarantee that it will consist of a single connected component. To demonstrate the importance and broad applicability of these results, we apply them to the study of the distribution of shortest path lengths on the giant component, percolation on the giant component, and spectra of sparse matrices defined on the giant component. We show that by using the degree distribution on the giant component one obtains high quality results for these properties, which can be further improved by taking the degree-degree correlations into account. This suggests that many existing methods, currently used for the analysis of the whole network, can be adapted in a straightforward fashion to yield results conditioned on the giant component.

Literature review of giant gartersnake (Thamnophis gigas) biology and conservation

USGS Publications Warehouse

Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

2015-08-03

This report reviews the available literature on giant gartersnakes (Thamnophis gigas) to compile existing information on this species and identify knowledge gaps that, if addressed, would help to inform conservation efforts for giant gartersnakes.  Giant gartersnakes comprise a species of semi-aquatic snake precinctive to wetlands in the Central Valley of California.  The diversion of surface water and conversion of wetlands to agricultural and other land uses resulted in the loss of more than 90 percent of natural giant gartersnake habitats.  Because of this habitat loss, giant gartersnakes are now listed by the United States and California Endangered Species Acts as Threatened.  Most extant populations occur in the rice-growing regions of the Sacramento Valley, which comprises the northern portion of the giant gartersnake’s former range.  The huge demand for water in California for agriculture, industry, recreation, and other human consumption, combined with periodic severe drought, places remaining giant gartersnake habitats at increased risk of degradation and loss.  This literature review summarizes the available information on giant gartersnake distribution, habitat relations, behavior, demography, and other aspects of its biology relevant to conservation.  This information is then compiled into a graphical conceptual model that indicates the importance of different aspects of giant gartersnake biology for maintaining positive population growth, and identifies those areas for which important information relevant for conservation is lacking.  Directing research efforts toward these aspects of giant gartersnake ecology will likely result in improvements to conserving this unique species while meeting the high demands for water in California.

Modeling and simulation of flow field in giant magnetostrictive pump

NASA Astrophysics Data System (ADS)

Zhao, Yapeng; Ren, Shiyong; Lu, Quanguo

2017-09-01

Recent years, there has been significant research in the design and analysis of giant magnetostrictive pump. In this paper, the flow field model of giant magnetostrictive pump was established and the relationship between pressure loss and working frequency of piston was studied by numerical simulation method. Then, the influence of different pump chamber height on pressure loss in giant magnetostrictive pump was studied by means of flow field simulation. Finally, the fluid pressure and velocity vector distribution in giant magnetostrictive pump chamber were simulated.

Sorption of ionic and nonionic organic solutes onto giant Miscanthus-derived biochar from methanol-water mixtures.

PubMed

Kim, Juhee; Hyun, Seunghun

2018-02-15

The sorption of naphthalene (NAP) and 1-naphthoic acid (1-NAPA) onto giant Miscanthus-derived biochar was investigated in methanol volume fractions (f c ) of 0-0.6 as a function of ionic composition (5mM CaCl 2 and 10mM KCl) and liquid pH (2 and 7). The sorption onto biochar was nonlinear with 0.42≤N≤0.95; thus, a concentration-specific sorption constant (K m ) was compared. The K m log linearly decreased with increasing f c , except for 1-NAPA from a CaCl 2 mixture at pH7. Isotherm data was fitted with a cosolvency sorption model through which the slope (ασ) of the inverse log linear K m -f c plot and empirical constant (α) were obtained. NAP sorption was well described by the cosolvency model with the α value being 0.41-0.53, indicating a methanol-biochar interaction favoring more sorption than the cosolvency based prediction. In particular, the slope (ασ) of 1-NAPA was lower than that of NAP, indicating less reduction of 1-NAPA sorption (i.e., lower α value) by methanol. In comparison with other sorbents, the α value was approximately intermediate between a humic substance and kaolinite clay. An analysis of FT-IR spectra suggested the transformation of O-containing functional groups by methanol, which will subsequently boost the π-π interaction between an organic solute and biochar. Moreover, Ca 2+ -induced sorption between anionic 1-NAPA and a negatively charged biochar surface was also fortified in the methanol mixture. The results revealed unexplored cosolvent effects on organic solute sorption onto biochar and identified the hydrophobic and hydrophilic sorption moieties of biochar as affected by the cosolvent. Copyright © 2017 Elsevier B.V. All rights reserved.

Giant magmatic water reservoirs at mid-crustal depth inferred from electrical conductivity and the growth of the continental crust

NASA Astrophysics Data System (ADS)

Laumonier, Mickael; Gaillard, Fabrice; Muir, Duncan; Blundy, Jon; Unsworth, Martyn

2017-01-01

The formation of the continental crust at subduction zones involves the differentiation of hydrous mantle-derived magmas through a combination of crystallization and crustal melting. However, understanding the mechanisms by which differentiation occurs at depth is hampered by the inaccessibility of the deep crust in active continental arcs. Here we report new high-pressure electrical conductivity and petrological experiments on hydrated andesitic melt from Uturuncu volcano on the Bolivian Altiplano. By applying our results to regional magnetotelluric data, we show that giant conductive anomalies at mid-crustal levels in several arcs are characterized by relatively low amounts of intergranular andesitic partial melts with unusually high dissolved water contents (≥8 wt.% H2O). Below Uturuncu, the Altiplano-Puna Magma Body (APMB) displays an electrical conductivity that requires high water content (up to 10 wt.%) dissolved in the melt based on crystal-liquid equilibria and melt H2O solubility experiments. Such a super-hydrous andesitic melt must constitute about 10% of the APMB, the remaining 90% being a combination of magmatic cumulates and older crustal rocks. The crustal ponding level of these andesites at around 6 kbar pressure implies that on ascent through the crust hydrous magmas reach their water saturation pressure in the mid-crust, resulting in decompression-induced crystallization that increases magma viscosity and in turn leads to preferential stalling and differentiation. Similar high conductivity features are observed beneath the Cascades volcanic arc and Taupo Volcanic Zone. This suggests that large amounts of water in super-hydrous andesitic magmas could be a common feature of active continental arcs and may illustrate a key step in the structure and growth of the continental crust. One Sentence Summary: Geophysical, laboratory conductivity and petrological experiments reveal that deep electrical conductivity anomalies beneath the Central Andes, Cascades and Taupo Volcanic Zone image the ponding of super-hydrous andesitic melts which contributes to the growth of continental crust.

Analysis of the influence of living environment and age on vaginal fungal microbiome in giant pandas (Ailuropoda melanoleuca) by high throughput sequencing.

PubMed

Chen, Danyu; Li, Caiwu; Feng, Lan; Zhang, Zhizhong; Zhang, Heming; Cheng, Guangyang; Li, Desheng; Zhang, Guiquan; Wang, Hongning; Chen, Yanxi; Feng, Mingfu; Wang, Chengdong; Wu, Honglin; Deng, Linhua; Ming, He; Yang, Xin

2018-02-01

A recent study has described the normal vaginal bacterial community in giant pandas, but there is a lack of knowledge of the fungal community residing in the vagina of giant pandas. In order to comprehensively understand the vaginal fungal microbial diversity and abundance in giant pandas, high throughput sequencing was used to analyse the ITS1 region, based on thirteen samples taken from the pandas' vaginas, which were grouped by sampling points and age. The results showed that the most abundant phyla were Basidiomycota (73.37%), followed by Ascomycota (20.04%), Zygomycota (5.23%), Glomeromycota (0.014%) and Chytridiomycota (0.006%). At the genus level, Guehomyces (37.92%) was the most abundant, followed by Cladosporium (9.072%), Trichosporon (6.2%) and Mucor (4.97%). Furthermore, Candida only accounted for a low percentage of the vaginal fungal community. With the saturation of rarefaction curves and fungal diversity indices, the samples from Dujiangyan and Chungking Safari Park (DC group) showed a higher fungal species richness and diversity than other living environments. Shannon diversity indices showed significant difference between group WL (Wolong nature reserve) and DC (P < .05). Additionally, a higher diversity was found in ten to fifteen years old (Group 2) than other groups. Group 2 and Group 3 displayed significant differences in the diversities of their vaginal fungal communities (P < .05). These data that has been collected from this research will be helpful for further study to improve the reproductive status of giant pandas. Copyright © 2018 Elsevier Ltd. All rights reserved.

INTERNAL ROTATION OF THE RED-GIANT STAR KIC 4448777 BY MEANS OF ASTEROSEISMIC INVERSION

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

Di Mauro, M. P.; Cardini, D.; Ventura, R.

We study the dynamics of the stellar interior of the early red-giant star KIC 4448777 by asteroseismic inversion of 14 splittings of the dipole mixed modes obtained from Kepler observations. In order to overcome the complexity of the oscillation pattern typical of red-giant stars, we present a procedure to extract the rotational splittings from the power spectrum. We find not only that the core rotates from a minimum of 8 to a maximum of 17 times faster than the surface, confirming previous inversion results generated for other red giants (Deheuvels et al.), but we also estimate the variation of the angularmore » velocity within the helium core with a spatial resolution of 0.001R and verify the hypothesis of a sharp discontinuity in the inner stellar rotation. The results show that the entire core rotates rigidly and provide evidence for an angular velocity gradient around the base of the hydrogen-burning shell; however, we do not succeed in characterizing the rotational slope, due to the intrinsic limits of the applied techniques. The angular velocity, from the edge of the core, appears to decrease with increasing distance from the center, reaching an average value in the convective envelope of 68 ± 22 nHz. We conclude that a set of data that includes only dipolar modes is sufficient to infer quite accurately the rotation of a red giant not only in the dense core but also, with a lower level of confidence, in part of the radiative region and in the convective envelope.« less

Functional annotation from the genome sequence of the giant panda.

PubMed

Huo, Tong; Zhang, Yinjie; Lin, Jianping

2012-08-01

The giant panda is one of the most critically endangered species due to the fragmentation and loss of its habitat. Studying the functions of proteins in this animal, especially specific trait-related proteins, is therefore necessary to protect the species. In this work, the functions of these proteins were investigated using the genome sequence of the giant panda. Data on 21,001 proteins and their functions were stored in the Giant Panda Protein Database, in which the proteins were divided into two groups: 20,179 proteins whose functions can be predicted by GeneScan formed the known-function group, whereas 822 proteins whose functions cannot be predicted by GeneScan comprised the unknown-function group. For the known-function group, we further classified the proteins by molecular function, biological process, cellular component, and tissue specificity. For the unknown-function group, we developed a strategy in which the proteins were filtered by cross-Blast to identify panda-specific proteins under the assumption that proteins related to the panda-specific traits in the unknown-function group exist. After this filtering procedure, we identified 32 proteins (2 of which are membrane proteins) specific to the giant panda genome as compared against the dog and horse genomes. Based on their amino acid sequences, these 32 proteins were further analyzed by functional classification using SVM-Prot, motif prediction using MyHits, and interacting protein prediction using the Database of Interacting Proteins. Nineteen proteins were predicted to be zinc-binding proteins, thus affecting the activities of nucleic acids. The 32 panda-specific proteins will be further investigated by structural and functional analysis.

Surgical Management of the Giant Pannus: Indications, Strategies, and Outcomes.

PubMed

Michaels, Joseph; Coon, Devin; Calotta, Nicholas A; Peter Rubin, J

2018-04-01

The obesity pandemic continues to produce an inexorable increase in the number of patients requiring surgical treatment of obesity and obesity-related complications. Along with this growing number of patients, there is a concomitant increase in the complexity of management. One particular example is the treatment of patients with an exceptionally large and morbid pannus. In this report, we detail the management of seven patients suffering from a giant pannus. Medical and surgical variables were assessed. A quality of life questionnaire was administered pre- and postoperatively. All seven patients suffered some obesity-related medical morbidity and six of seven (86%) had local complications of the giant pannus. Each patient underwent giant panniculectomy [resection weight > 13. 6 kg (30 lb)]. The mean resection weight was 20.0 kg. Four of seven (57%) patients experienced postoperative complications, with two (29%) requiring re-operation and blood transfusion. Six patients were available for long-term follow-up; 100% of participants indicated an increased quality of life while five (83%) reported additional postoperative weight loss, increase in exercise frequency and walking ability, and improved ability to work. Our results indicate that giant panniculectomy is a challenging and risky procedure, but careful patient selection and intraoperative scrutiny can ameliorate these risks and afford patients a dramatically improved quality of life. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Chemical Composition of NGC 5824, a Globular Cluster without Iron Spread but with an Extreme Mg–Al Anticorrelation

NASA Astrophysics Data System (ADS)

Mucciarelli, Alessio; Lapenna, Emilio; Ferraro, Francesco R.; Lanzoni, Barbara

2018-05-01

NGC 5824 is a massive Galactic globular cluster suspected to have an intrinsic spread in its iron content, according to the strength of the calcium triplet lines. We present chemical abundances of 117 cluster giant stars using high-resolution spectra acquired with the multi-object spectrograph FLAMES. The metallicity distribution of 87 red giant branch stars is peaked at [Fe/H] = ‑2.11 ± 0.01 dex, while that derived from 30 asymptotic giant branch stars is peaked at [Fe/H] = ‑2.20 ± 0.01 dex. Both the distributions are compatible with a null spread, indicating that this cluster did not retain the ejecta of supernovae. The small iron abundance offset between the two groups of stars is similar to the abundances already observed among red and asymptotic giant branch stars in other clusters. The lack of intrinsic iron spread rules out the possibility that NGC 5824 is the remnant of a disrupted dwarf galaxy, as previously suggested. We also find evidence of the chemical anomalies usually observed in globular clusters, namely the Na–O and the Mg–Al anticorrelations. In particular, NGC 5824 exhibits a huge range of [Mg/Fe] abundance, observed in only a few metal-poor and/or massive clusters. We conclude that NGC 5824 is a normal globular cluster, without spread in [Fe/H] but with an unusually large spread in [Mg/Fe], possibly due to an efficient self-enrichment driven by massive asymptotic giant branch stars. Based on observations collected at the ESO-VLT under the program 095.D-0290.

Population genetics of Enterocytozoon bieneusi in captive giant pandas of China.

PubMed

Li, Wei; Song, Yuan; Zhong, Zhijun; Huang, Xiangming; Wang, Chengdong; Li, Caiwu; Yang, Haidi; Liu, Haifeng; Ren, Zhihua; Lan, Jingchao; Wu, Kongju; Peng, Guangneng

2017-10-18

Most studies on Enterocytozoon bieneusi are conducted based on the internal transcribed spacer (ITS) region of the rRNA gene, whereas some have examined E. bieneusi population structures. Currently, the population genetics of this pathogen in giant panda remains unknown. The objective of this study was to determine the E. bieneusi population in captive giant pandas in China. We examined 69 E. bieneusi-positive specimens from captive giant pandas in China using five loci (ITS, MS1, MS3, MS4 and MS7) to infer E. bieneusi population genetics. For multilocus genotype (MLG) analysis of E. bieneusi-positive isolates, the MS1, MS3, MS4, and MS7 microsatellite and minisatellite loci were amplified and sequenced in 48, 45, 50 and 47 specimens, respectively, generating ten, eight, nine and five types. We successfully amplified 36 specimens and sequenced all five loci, forming 24 MLGs. Multilocus sequence analysis revealed a strong and significant linkage disequilibrium (LD), indicating a clonal population. This result was further supported by measurements of pairwise intergenic LD and a standardized index of association (I S A ) from allelic profile data. The analysis in STRUCTURE suggested three subpopulations in E. bieneusi, further confirmed using right's fixation index (F ST ). Subpopulations 1 and 2 exhibited an epidemic structure, whereas subpopulation 3 had a clonal structure. Our results describe E. bieneusi population genetics in giant pandas for the first time, improving the current understanding E. bieneusi epidemiology in the studied region. These data also benefit future studies exploring potential transmission risks from pandas to other animals, including humans.

A scaling relationship for impact-induced melt volume

NASA Astrophysics Data System (ADS)

Nakajima, M.; Rubie, D. C.; Melosh, H., IV; Jacobson, S. A.; Golabek, G.; Nimmo, F.; Morbidelli, A.

2016-12-01

During the late stages of planetary accretion, protoplanets experience a number of giant impacts and extensive mantle melting. The impactor's core sinks through the molten part of the target mantle (magma ocean) and experiences metal-silicate partitioning (e.g., Stevenson, 1990). For understanding the chemical evolution of the planetary mantle and core, we need to determine the impact-induced melt volume because the partitioning strongly depends on the ranges of the pressures and temperatures within the magma ocean. Previous studies have investigated the effects of small impacts (i.e. impact cratering) on melt volume, but those for giant impacts are not well understood yet. Here, we perform giant impact simulations to derive a scaling law for melt volume as a function of impact velocity, impact angle, and impactor-to-target mass ratio. We use two different numerical codes, namely smoothed particle hydrodynamics we developed (SPH, a particle method) and the code iSALE (a grid-based method) to compare their outcomes. Our simulations show that these two codes generally agree as long as the same equation of state is used. We also find that some of the previous studies developed for small impacts (e.g., Abramov et al., 2012) overestimate giant impact melt volume by orders of magnitudes partly because these models do not consider self-gravity of the impacting bodies. Therefore, these models may not be extrapolated to large impacts. Our simulations also show that melt volume can be scaled by the total mass of the system. In this presentation, we further discuss geochemical implications for giant impacts on planets, including Earth and Mars.

Radial Distributions of Sub-Populations in the Globular Cluster M15: A More Centrally Concentrated Primordial Population

NASA Astrophysics Data System (ADS)

Larsen, Søren S.; Baumgardt, Holger; Bastian, Nate; Brodie, Jean P.; Grundahl, Frank; Strader, Jay

2015-05-01

We examine the radial distributions of stellar populations in the globular cluster (GC) M15, using Hubble Space Telescope/Wide Field Camera 3 (WFC3) photometry of red giants in the nitrogen-sensitive F343N-F555W color. Surprisingly, we find that giants with “primordial” composition (i.e., N abundances similar to those in field stars) are the most centrally concentrated within the WFC3 field. We then combine our WFC3 data with Sloan Digital Sky Survey u,g photometry and find that the trend reverses for radii ≳ 1\\prime (3 pc) where the ratio of primordial to N-enhanced giants increases outward, as already found by Lardo et al. The ratio of primordial to enriched stars thus has a U-shaped dependency on radius with a minimum near the half-light radius. N-body simulations show that mass segregation might produce a trend resembling the observed one, but only if the N-enhanced giants are ˜ 0.25 {{M}⊙ } less massive than the primordial giants, which requires extreme He enhancement (Y≳ 0.40). However, such a large difference in Y is incompatible with the negligible optical color differences between primordial and enriched giants, which suggest {Δ }Y≲ 0.03 and thus a difference in turn-off mass of {Δ }M≲ 0.04 {{M}⊙ } between the different populations. The radial trends in M15 are thus unlikely to be of dynamical origin and presumably reflect initial conditions, a result that challenges all current GC formation scenarios. We note that population gradients in the central regions of GCs remain poorly investigated and may show a more diverse behavior than hitherto thought. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13295.

Complete genome sequence and comparative genome analysis of Klebsiella oxytoca HKOPL1 isolated from giant panda feces.

PubMed

Jiang, Jingwei; Tun, Hein Min; Mauroo, Nathalie France; Ma, Angel Po Yee; Chan, San Yuen; Leung, Frederick C

2014-11-23

The giant panda (Ailuropoda melanoleuca) is an endangered species well-known for ingesting bamboo as a major part of their diet despite the fact that it belongs to order Carnivora. However, the giant panda's draft genome shows no direct evidence of enzymatic genes responsible for cellulose digestion. To explore this phenomenon, we study the giant panda's gut microbiota using genomic approaches in order to better understand their physiological processes as well as any potential microbial cellulose digestion processes. A complete genome of isolated Klebsiella oxytoca HKOPL1 of 5.9 Mb has been successfully sequenced, closed and comprehensively annotated against various databases. Genome comparisons within the Klebsiella genus and K. oxytoca species have also been performed. A total of 5,772 genes were predicted, and among them, 211 potential virulence genes, 35 pathogenicity island-like regions, 1,615 potential horizontal transferring genes, 23 potential antibiotics resistant genes, a potential prophage integrated region, 8 genes in 2,3-Butanediol production pathway and 3 genes in the cellulose degradation pathway could be identified and discussed based on the comparative genomic studies between the complete genome sequence of K. oxytoca HKOPL1 and other Klebsiella strains. A functional study shows that K. oxytoca HKOPL1 can degrade cellulose within 72 hours. Phylogenomic studies indicate that K. oxytoca HKOPL1 is clustered with K. oxytoca strains 1686 and E718. K. oxytoca HKOPL1 is a gram-negative bacterium able to degrade cellulose. We report here the first complete genome sequence of K. oxytoca isolated from giant panda feces. These studies have provided further insight into the role of gut microbiota in giant panda digestive physiology. In addition, K. oxytoca HKOPL1 has the potential for biofuel application in terms of cellulose degradation and potential for the production of 2,3-Butanediol (an important industrial raw material).

Giant Planets: Good Neighbors for Habitable Worlds?

NASA Astrophysics Data System (ADS)

Georgakarakos, Nikolaos; Eggl, Siegfried; Dobbs-Dixon, Ian

2018-04-01

The presence of giant planets influences potentially habitable worlds in numerous ways. Massive celestial neighbors can facilitate the formation of planetary cores and modify the influx of asteroids and comets toward Earth analogs later on. Furthermore, giant planets can indirectly change the climate of terrestrial worlds by gravitationally altering their orbits. Investigating 147 well-characterized exoplanetary systems known to date that host a main-sequence star and a giant planet, we show that the presence of “giant neighbors” can reduce a terrestrial planet’s chances to remain habitable, even if both planets have stable orbits. In a small fraction of systems, however, giant planets slightly increase the extent of habitable zones provided that the terrestrial world has a high climate inertia. In providing constraints on where giant planets cease to affect the habitable zone size in a detrimental fashion, we identify prime targets in the search for habitable worlds.

POST ASYMPTOTIC GIANT BRANCH BIPOLAR REFLECTION NEBULAE: RESULT OF DYNAMICAL EJECTION OR SELECTIVE ILLUMINATION?

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

Koning, N.; Kwok, Sun; Steffen, W., E-mail: nico.koning@ucalgary.ca, E-mail: sunkwok@hku.hk, E-mail: wsteffen@astrosen.unam.mx

2013-03-10

A model for post asymptotic giant branch bipolar reflection nebulae has been constructed based on a pair of evacuated cavities in a spherical dust envelope. Many of the observed features of bipolar nebulae, including filled bipolar lobes, an equatorial torus, searchlight beams, and a bright central light source, can be reproduced. The effects on orientation and dust densities are studied and comparisons with some observed examples are offered. We suggest that many observed properties of bipolar nebulae are the result of optical effects and any physical modeling of these nebulae has to take these factors into consideration.

Enhanced giant magnetoimpedance in heterogeneous nanobrush

PubMed Central

2012-01-01

A highly sensitive and large working range giant magnetoimpedance (GMI) effect is found in the novel nanostructure: nanobrush. The nanostructure is composed of a soft magnetic nanofilm and a nanowire array, respectively fabricated by RF magnetron sputtering and electrochemical deposition. The optimal GMI ratio of nanobrush is promoted to more than 250%, higher than the pure FeNi film and some sandwich structures at low frequency. The design of this structure is based on the vortex distribution of magnetic moments in thin film, and it can be induced by the exchange coupling effect between the interfaces of nanobrush. PMID:22963551

Water in dense molecular clouds

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

Wannier, P.G.; Kuiper, T.B.H.; Frerking, M.A.

1991-08-01

The G.P. Kuiper Airborne Observatory (KAO) was used to make initial observations of the half-millimeter ground-state transition of water in seven giant molecular clouds and in two late-type stars. No significant detections were made, and the resulting upper limits are significantly below those expected from other, indirect observations and from several theoretical models. The implied interstellar H2O/CO abundance is less than 0.003 in the cores of three giant molecular clouds. This value is less than expected from cloud chemistry models and also than estimates based on HDO and H3O(+) observations. 78 refs.

A decade of improvements in Mimiviridae and Marseilleviridae isolation from amoeba.

PubMed

Pagnier, Isabelle; Reteno, Dorine-Gaelle Ikanga; Saadi, Hanene; Boughalmi, Mondher; Gaia, Morgan; Slimani, Meriem; Ngounga, Tatsiana; Bekliz, Meriem; Colson, Philippe; Raoult, Didier; La Scola, Bernard

2013-01-01

Since the isolation of the first giant virus, the Mimivirus, by T.J. Rowbotham in a cooling tower in Bradford, UK, and after its characterisation by our group in 2003, we have continued to develop novel strategies to isolate additional strains. By first focusing on cooling towers using our original time-consuming procedure, we were able to isolate a new lineage of giant virus called Marseillevirus and a new Mimivirus strain called Mamavirus. In the following years, we have accumulated the world's largest unique collection of giant viruses by improving the use of antibiotic combinations to avoid bacterial contamination of amoeba, developing strategies of preliminary screening of samples by molecular methods, and using a high-throughput isolation method developed by our group. Based on the inoculation of nearly 7,000 samples, our collection currently contains 43 strains of Mimiviridae (14 in lineage A, 6 in lineage B, and 23 in lineage C) and 17 strains of Marseilleviridae isolated from various environments, including 3 of human origin. This study details the procedures used to build this collection and paves the way for the high-throughput isolation of new isolates to improve the record of giant virus distribution in the environment and the determination of their pangenome.

Quantifying the evidence for co-benefits between species conservation and climate change mitigation in giant panda habitats.

PubMed

Li, Renqiang; Xu, Ming; Powers, Ryan; Zhao, Fen; Jetz, Walter; Wen, Hui; Sheng, Qingkai

2017-10-05

Conservationists strive for practical, cost-effective management solutions to forest-based species conservation and climate change mitigation. However, this is compromised by insufficient information about the effectiveness of protected areas in increasing carbon storage, and the co-benefits of species and carbon conservation remain poorly understood. Here, we present the first rigorous quantitative assessment of the roles of giant panda nature reserves (NRs) in carbon sequestration, and explore the co-benefits of habitat conservation and climate change mitigation. Results show that more than 90% of the studied panda NRs are effective in increasing carbon storage, with the mean biomass carbon density of the whole NRs exhibiting a 4.2% higher growth rate compared with lands not declared as NRs over the period 1988-2012, while this effectiveness in carbon storage masks important patterns of spatial heterogeneity across the giant panda habitats. Moreover, the significant associations have been identified between biomass carbon density and panda's habitat suitability in ~85% NRs and at the NR level. These findings suggest that the planning for carbon and species conservation co-benefits would enhance the greatest return on limited conservation investments, which is a critical need for the giant panda after its conservation status has been downgraded from "endangered" to "vulnerable".

Ultrafast Electric Field Pulse Control of Giant Temperature Change in Ferroelectrics

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

Qi, Y.; Liu, S.; Lindenberg, A. M.

There is a surge of interest in developing environmentally friendly solid-state-based cooling technology. Here, we point out that a fast cooling rate (≈ 10 11 K/s) can be achieved by driving solid crystals to a high-temperature phase with a properly designed electric field pulse. Specifically, we predict that an ultrafast electric field pulse can cause a giant temperature decrease up to 32 K in PbTiO 3 occurring on few picosecond time scales. Here, we explain the underlying physics of this giant electric field pulse-induced temperature change with the concept of internal energy redistribution: the electric field does work on amore » ferroelectric crystal and redistributes its internal energy, and the way the kinetic energy is redistributed determines the temperature change and strongly depends on the electric field temporal profile. This concept is supported by our all-atom molecular dynamics simulations of PbTiO 3 and BaTiO 3. Moreover, this internal energy redistribution concept can also be applied to understand electrocaloric effect. We further propose new strategies for inducing giant cooling effect with ultrafast electric field pulse. This Letter offers a general framework to understand electric-field-induced temperature change and highlights the opportunities of electric field engineering for controlled design of fast and efficient cooling technology.« less

Ultrafast Electric Field Pulse Control of Giant Temperature Change in Ferroelectrics

DOE PAGES

Qi, Y.; Liu, S.; Lindenberg, A. M.; ...

2018-01-30

There is a surge of interest in developing environmentally friendly solid-state-based cooling technology. Here, we point out that a fast cooling rate (≈ 10 11 K/s) can be achieved by driving solid crystals to a high-temperature phase with a properly designed electric field pulse. Specifically, we predict that an ultrafast electric field pulse can cause a giant temperature decrease up to 32 K in PbTiO 3 occurring on few picosecond time scales. Here, we explain the underlying physics of this giant electric field pulse-induced temperature change with the concept of internal energy redistribution: the electric field does work on amore » ferroelectric crystal and redistributes its internal energy, and the way the kinetic energy is redistributed determines the temperature change and strongly depends on the electric field temporal profile. This concept is supported by our all-atom molecular dynamics simulations of PbTiO 3 and BaTiO 3. Moreover, this internal energy redistribution concept can also be applied to understand electrocaloric effect. We further propose new strategies for inducing giant cooling effect with ultrafast electric field pulse. This Letter offers a general framework to understand electric-field-induced temperature change and highlights the opportunities of electric field engineering for controlled design of fast and efficient cooling technology.« less

Ultrafast Electric Field Pulse Control of Giant Temperature Change in Ferroelectrics

NASA Astrophysics Data System (ADS)

Qi, Y.; Liu, S.; Lindenberg, A. M.; Rappe, A. M.

2018-01-01

There is a surge of interest in developing environmentally friendly solid-state-based cooling technology. Here, we point out that a fast cooling rate (≈1011 K /s ) can be achieved by driving solid crystals to a high-temperature phase with a properly designed electric field pulse. Specifically, we predict that an ultrafast electric field pulse can cause a giant temperature decrease up to 32 K in PbTiO3 occurring on few picosecond time scales. We explain the underlying physics of this giant electric field pulse-induced temperature change with the concept of internal energy redistribution: the electric field does work on a ferroelectric crystal and redistributes its internal energy, and the way the kinetic energy is redistributed determines the temperature change and strongly depends on the electric field temporal profile. This concept is supported by our all-atom molecular dynamics simulations of PbTiO3 and BaTiO3 . Moreover, this internal energy redistribution concept can also be applied to understand electrocaloric effect. We further propose new strategies for inducing giant cooling effect with ultrafast electric field pulse. This Letter offers a general framework to understand electric-field-induced temperature change and highlights the opportunities of electric field engineering for controlled design of fast and efficient cooling technology.

Giant Olfactory Meningiomas

PubMed Central

d'Avella, Domenico; Salpietro, Francesco M.; Alafaci, Cetty; Tomasello, Francesco

1999-01-01

Olfactory groove meningiomas may attain surprisingly large size. The subfrontal approach is currently the route preferred by most neurosurgeons for their excision. The pterional-transsylvian route represents an alternate exposure for microsurgery of frontobasal tumors. Although this approach has been already described for olfactory meningiomas, tumors of giant size were not specifically addressed in the literature. We report the application of the pterional-transsylvian approach in six patients with giant olfactory meningiomas. This series is unique because it includes only patients with tumors exceeding 6 cm in diameter with bilateral symmetrical development. A radical removal was achieved in all patients and all of them made a full recovery. To investigate the relevance of the pterional-transsylvian approach for minimizing surgical morbidity, a magnetic resonance imaging protocol was designed to characterize even subtle postoperative frontal lobe structural changes. These changes, limited to the frontal lobe ipsilateral to exposure and localized in specific anatomical domains of the prefrontal area, included cystic degenerative alterations, parenchymal gliosis, and associated persistent white matter edema. Results from the present series strengthen the usefulness of the pterional-transsylvian approach as a safe surgical route for lesions affecting the anterior skull base, even with huge bilateral symmetrical expansion, such as giant olfactory meningiomas. ImagesFigure 1Figure 2Figure 3p26-bFigure 4p27-bFigure 5Figure 6Figure 7 PMID:17171078

CHROMOSPHERIC MODELS AND THE OXYGEN ABUNDANCE IN GIANT STARS

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

Dupree, A. K.; Avrett, E. H.; Kurucz, R. L., E-mail: dupree@cfa.harvard.edu

Realistic stellar atmospheric models of two typical metal-poor giant stars in Omega Centauri, which include a chromosphere (CHR), influence the formation of optical lines of O i: the forbidden lines (λ6300, λ6363) and the infrared triplet (λλ7771−7775). One-dimensional semi-empirical non-local thermodynamic equilibrium (LTE) models are constructed based on observed Balmer lines. A full non-LTE formulation is applied for evaluating the line strengths of O i, including photoionization by the Lyman continuum and photoexcitation by Lyα and Lyβ. Chromospheric models (CHR) yield forbidden oxygen transitions that are stronger than those in radiative/convective equilibrium (RCE) models. The triplet oxygen lines from highmore » levels also appear stronger than those produced in an RCE model. The inferred oxygen abundance from realistic CHR models for these two stars is decreased by factors of ∼3 as compared to values derived from RCE models. A lower oxygen abundance suggests that intermediate-mass AGB stars contribute to the observed abundance pattern in globular clusters. A change in the oxygen abundance of metal-poor field giants could affect models of deep mixing episodes on the red giant branch. Changes in the oxygen abundance can impact other abundance determinations that are critical to astrophysics, including chemical tagging techniques and galactic chemical evolution.« less

OXYGEN AND SODIUM ABUNDANCES IN M13 (NGC 6205) GIANTS: LINKING GLOBULAR CLUSTER FORMATION SCENARIOS, DEEP MIXING, AND POST-RGB EVOLUTION

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

Johnson, Christian I.; Pilachowski, Catherine A., E-mail: cijohnson@astro.ucla.edu, E-mail: catyp@astro.indiana.edu

We present O, Na, and Fe abundances, as well as radial velocities, for 113 red giant branch (RGB) and asymptotic giant branch (AGB) stars in the globular cluster M13. The abundances and velocities are based on spectra obtained with the WIYN-Hydra spectrograph, and the observations range in luminosity from the horizontal branch (HB) to RGB tip. The results are examined in the context of recent globular cluster formation scenarios. We find that M13 exhibits many key characteristics that suggest its formation and chemical enrichment are well described by current models. Some of these observations include the central concentration of O-poormore » stars, the notable decrease in [O/Fe] (but small increase in [Na/Fe]) with increasing luminosity that affects primarily the 'extreme' population, the small fraction of stars with halo-like composition, and the paucity of O-poor AGB stars. In agreement with recent work, we conclude that the most O-poor M13 giants are likely He-enriched and that most (all?) O-poor RGB stars evolve to become extreme HB and AGB-manque stars. In contrast, the 'primordial' and 'intermediate' population stars appear to experience standard HB and AGB evolution.« less

Manta birostris, predator of the deep? Insight into the diet of the giant manta ray through stable isotope analysis.

PubMed

Burgess, Katherine B; Couturier, Lydie I E; Marshall, Andrea D; Richardson, Anthony J; Weeks, Scarla J; Bennett, Michael B

2016-11-01

The characterization of diet for the giant manta ray Manta birostris has been problematic given their large-scale movement patterns and the difficulty in obtaining stomach contents from this species. The large majority of existing information is based on observational data limited to feeding events at the sea surface during daylight. Recently discovered aggregation sites for the giant manta ray off mainland Ecuador are some of the most accessible to date and provide a unique opportunity for researchers to gather much needed information on this elusive species. To assess how important surface zooplankton is to giant manta ray diet, we conducted stable isotope analysis ( 15 N and 13 C) on M. birostris muscle and surface zooplankton. Trophic position estimates placed M. birostris overall at a secondary consumer level of approximately 3.4 but there was large variation in δ 15 N and δ 13 C values among individuals. Manta birostris muscle tissue δ 13 C values were also not consistent with this species feeding predominantly on surface zooplankton and suggest that the majority of dietary intake is of mesopelagic origin. Given the conservative life history and fisheries pressure on large planktivores, knowledge of their trophic role and foraging strategies is essential to better understand their ecology and develop effective conservation measures.

The Optical Gravitational Lensing Experiment: Red Clump Stars as a Distance Indicator.

PubMed

Udalski

2000-03-01

We present relation of the mean I-band brightness of red clump stars on metallicity. Red clump stars were proposed to be a very attractive standard candle for distance determination. The calibration is based on 284 nearby red giant stars whose high-quality spectra made it possible to determine accurate individual metal abundances. High-quality parallaxes (sigmapi&solm0;pi<10%) and photometry of these very bright stars come from Hipparcos measurements. Metallicity of the sample covers a large range: -0.6 dex<&sqbl0;Fe&solm0;H&sqbr0;<+0.2 dex. We find a weak dependence of the mean I-band brightness on metallicity ( approximately 0.13 mag dex-1). What is more important, the range of metallicity of the Hipparcos sample partially overlaps with metallicity of field giants in the LMC, thus making it possible to determine the distance to the LMC by almost direct comparison of brightness of the local Hipparcos red clump giants with that of LMC stars. Photometry of field red clump giants in nine low-extinction fields of the LMC halo collected during the OGLE II microlensing survey compared with the Hipparcos red clump stars data yields the distance modulus to the LMC: &parl0;m-M&parr0;LMC=18.24+/-0.08 mag.

Giant midesophageal diverticulum presenting as food impaction: case report and review of the literature.

PubMed

Hadi, Usamah; Rameh, Charbel

2007-01-01

A giant midesophageal diverticulum is a medical rarity that is usually asymptomatic, and discovered incidentally. We report a case of a giant midesophageal diverticulum that revealed itself secondary to food impaction. A literature review on epidemiology, etiology, clinical presentation, investigations, and management of giant midesophageal diverticula will be highlighted.

Biomass yield comparisons of giant miscanthus, giant reed, and miscane grown under irrigated and rainfed conditions

USDA-ARS?s Scientific Manuscript database

The U.S. Department of Energy has initiated efforts to decrease the nation’s dependence on imported oil by developing domestic renewable sources of cellulosic-derived bioenergy. In this study, giant miscanthus (Miscanthus x giganteus), sugarcane (complex hybrid of Saccharum spp.), and giant reed (Ar...

Estimation of the growth curve and heritability of the growth rate for giant panda (Ailuropoda melanoleuca) cubs.

PubMed

Che, T D; Wang, C D; Jin, L; Wei, M; Wu, K; Zhang, Y H; Zhang, H M; Li, D S

2015-03-27

Giant panda cubs have a low survival rate during the newborn and early growth stages. However, the growth and developmental parameters of giant panda cubs during the early lactation stage (from birth to 6 months) are not well known. We examined the growth and development of giant panda cubs by the Chapman growth curve model and estimated the heritability of the maximum growth rate at the early lactation stage. We found that 83 giant panda cubs reached their maximum growth rate at approximately 75-120 days after birth. The body weight of cubs at 75 days was 4285.99 g. Furthermore, we estimated that the heritability of the maximum growth rate was moderate (h(2) = 0.38). Our study describes the growth and development of giant panda cubs at the early lactation stage and provides valuable growth benchmarks. We anticipate that our results will be a starting point for more detailed research on increasing the survival rate of giant panda cubs. Feeding programs for giant panda cubs need further improvement.

MOLECULAR CLONING, SEQUENCING, EXPRESSION AND BIOLOGICAL ACTIVITY OF GIANT PANDA (AILUROPODA MELANOLEUCA) INTERFERON-GAMMA.

PubMed

Zhu, Hui; Wang, Wen-Xiu; Wang, Bao-Qin; Zhu, Xiao-Fu; Wu, Xu-Jin; Ma, Qing-Yi; Chen, De-Kun

2012-06-29

The giant panda (Ailuropoda melanoleuca) is an endangered species and indigenous to China. Interferon-gamma (IFN-γ) is the only member of type □ IFN and is vital for the regulation of host adapted immunity and inflammatory response. Little is known aboutthe FN-γ gene and its roles in giant panda.In this study, IFN-γ gene of Qinling giant panda was amplified from total blood RNA by RT-CPR, cloned, sequenced and analysed. The open reading frame (ORF) of Qinling giant panda IFN-γ encodes 152 amino acidsand is highly similar to Sichuan giant panda with an identity of 99.3% in cDNA sequence. The IFN-γ cDNA sequence was ligated to the pET32a vector and transformed into E. coli BL21 competent cells. Expression of recombinant IFN-γ protein of Qinling giant panda in E. coli was confirmed by SDS-PAGE and Western blot analysis. Biological activity assay indicated that the recombinant IFN-γ protein at the concentration of 4-10 µg/ml activated the giant panda peripheral blood lymphocytes,while at 12 µg/mlinhibited. the activation of the lymphocytes.These findings provide insights into the evolution of giant panda IFN-γ and information regarding amino acid residues essential for their biological activity.

[Prevalence and clinicopathological characteristics of giant cell tumors].

PubMed

Estrada-Villaseñor, E G; Linares-González, L M; Delgado-Cedillo, E A; González-Guzmán, R; Rico-Martínez, G

2015-01-01

The frequency of giant cell tumors reported in the literature is very variable. Considering that our population has its own features, which distinguish it from the Anglo-Saxon and Asian populations, we think that both the frequency and the clinical characteristics of giant cell tumors in our population are different. The major aim of this paper was to determine the frequency and clinicopathological characteristics of giant cell tumors of the bone. A cross-sectional descriptive study was conducted of the cases diagnosed at our service as giant cell tumors of the bone from January to December 2013. The electronic clinical records, radiologic records and histologic slides from each case were reviewed. Giant cell tumors represented 17% of total bone tumors and 28% of benign tumors. Patients included 13 females and 18 males. The most frequent locations of giant cell tumors were: the proximal tibia, 9 cases (29%), and the distal femur, 6 cases (19%). Forty-five percent of giant cell tumors were associated with aneurysmal bone cyst (ABC) (14 cases) and one case (3%) was malignant. The frequency of giant cell tumors in this case series was intermediate, that is, higher than the one reported in Anglo-Saxon countries (usually low), but without reaching the frequency rates reported in Asian countries (high).

Restricted access Giant kelp, Macrocystis pyrifera, increases faunal diversity through physical engineering

USGS Publications Warehouse

Miller, Robert J.; Lafferty, Kevin D.; Lamy, Thomas; Kui, Li; Rassweiler, Andrew; Reed, Daniel C.

2018-01-01

Foundation species define the ecosystems they live in, but ecologists have often characterized dominant plants as foundational without supporting evidence. Giant kelp has long been considered a marine foundation species due to its complex structure and high productivity; however, there is little quantitative evidence to evaluate this. Here, we apply structural equation modelling to a 15-year time series of reef community data to evaluate how giant kelp affects the reef community. Although species richness was positively associated with giant kelp biomass, most direct paths did not involve giant kelp. Instead, the foundational qualities of giant kelp were driven mostly by indirect effects attributed to its dominant physical structure and associated engineering influence on the ecosystem, rather than by its use as food by invertebrates and fishes. Giant kelp structure has indirect effects because it shades out understorey algae that compete with sessile invertebrates. When released from competition, sessile species in turn increase the diversity of mobile predators. Sea urchin grazing effects could have been misinterpreted as kelp effects, because sea urchins can overgraze giant kelp, understorey algae and sessile invertebrates alike. Our results confirm the high diversity and biomass associated with kelp forests, but highlight how species interactions and habitat attributes can be misconstrued as direct consequences of a foundation species like giant kelp.

Dietary resources shape the adaptive changes of cyanide detoxification function in giant panda (Ailuropoda melanoleuca)

PubMed Central

Huang, He; Yie, Shangmian; Liu, Yuliang; Wang, Chengdong; Cai, Zhigang; Zhang, Wenping; Lan, Jingchao; Huang, Xiangming; Luo, Li; Cai, Kailai; Hou, Rong; Zhang, Zhihe

2016-01-01

The functional adaptive changes in cyanide detoxification in giant panda appear to be response to dietary transition from typical carnivore to herbivorous bear. We tested the absorption of cyanide contained in bamboo/bamboo shoots with a feeding trial in 20 adult giant pandas. We determined total cyanide content in bamboo shoots and giant panda’s feces, levels of urinary thiocyanate and tissue rhodanese activity using color reactions with a spectrophotometer. Rhodanese expression in liver and kidney at transcription and translation levels were measured using real-time RT-PCR and immunohistochemistry, respectively. We compared differences of rhodanese activity and gene expressions among giant panda, rabbit (herbivore) and cat (carnivore), and between newborn and adult giant pandas. Bamboo shoots contained 3.2 mg/kg of cyanide and giant pandas absorbed more than 65% of cyanide. However, approximately 80% of absorbed cyanide was metabolized to less toxic thiocyanate that was discharged in urine. Rhodanese expression and activity in liver and kidney of giant panda were significantly higher than in cat, but lower than in rabbit (all P < 0.05). Levels in adult pandas were higher than that in newborn cub. Phylogenetic analysis of both nucleotide and amino acid sequences of the rhodanese gene supported a closer relationship of giant panda with carnivores than with herbivores. PMID:27703267

Dietary resources shape the adaptive changes of cyanide detoxification function in giant panda (Ailuropoda melanoleuca).

PubMed

Huang, He; Yie, Shangmian; Liu, Yuliang; Wang, Chengdong; Cai, Zhigang; Zhang, Wenping; Lan, Jingchao; Huang, Xiangming; Luo, Li; Cai, Kailai; Hou, Rong; Zhang, Zhihe

2016-10-05

The functional adaptive changes in cyanide detoxification in giant panda appear to be response to dietary transition from typical carnivore to herbivorous bear. We tested the absorption of cyanide contained in bamboo/bamboo shoots with a feeding trial in 20 adult giant pandas. We determined total cyanide content in bamboo shoots and giant panda's feces, levels of urinary thiocyanate and tissue rhodanese activity using color reactions with a spectrophotometer. Rhodanese expression in liver and kidney at transcription and translation levels were measured using real-time RT-PCR and immunohistochemistry, respectively. We compared differences of rhodanese activity and gene expressions among giant panda, rabbit (herbivore) and cat (carnivore), and between newborn and adult giant pandas. Bamboo shoots contained 3.2 mg/kg of cyanide and giant pandas absorbed more than 65% of cyanide. However, approximately 80% of absorbed cyanide was metabolized to less toxic thiocyanate that was discharged in urine. Rhodanese expression and activity in liver and kidney of giant panda were significantly higher than in cat, but lower than in rabbit (all P < 0.05). Levels in adult pandas were higher than that in newborn cub. Phylogenetic analysis of both nucleotide and amino acid sequences of the rhodanese gene supported a closer relationship of giant panda with carnivores than with herbivores.

Changes of foraging patch selection and utilization by a giant panda after bamboo flowering.

PubMed

Li, Guochun; Song, Huadong; Altigani, Latifa A A; Zheng, Xueli; Bu, Shuhai

2017-07-01

The bamboo flowering leads to the habitat fragmentation and food quality decline of a giant panda. Few empirical research has been conducted about the giant panda's response to the bamboo flowering. Here, we investigated the characteristics of bamboo stands, giant panda's activity, and selection and utilization of bamboo stands by giant panda in Taibaishan National Nature Reserve, China, over a 3-year period (September 2013-May 2016) during the Fargesia qinlingensis flowering period. Our results indicated that the proportion of whole bamboo stands flowering has gradually expanded from 26.7% in 2013 and 33.9% in 2014 to 52.3% in 2015. Although the flowering bamboo has lower crude protein and higher crude fiber than a non-flowering bamboo, the giant panda still fed on flowering bamboo from the evidence of droppings. The giant panda left its feeding sites and moved to the high elevation along river when the proportion of flowering reached 69.2% at elevation of 2350-2450 m in the third year. With the decline of the quality of bamboo stand of Fargesia qinlingensis, the giant panda abandoned its feeding sites when the threshold value of bamboo flowering reached 56.9-69.2%. Flexibility in foraging strategy and spatial behavior can help the giant panda to better adapt to the environment.

Other Targets in the Search for Life--from Saturn's Titan to Planetary Systems around other Stars

NASA Astrophysics Data System (ADS)

Lunine, J. I.

2001-12-01

In addition to the ``standard" targets in the search for life beyond Earth--namely Mars, Europa, and putative extra-solar terrestrial planets--there are others that are key to informing us as to the origin and persistence of life in the cosmos. Saturn's moon Titan, with its dense nitrogen atmosphere rich in methane, may hold important clues to how abiotic organic chemistry evolves toward biochemistry. In particular, while the stratospheric processing of methane and nitrogen by ultraviolet photons and cosmic rays generates a free radical chemistry that is by itself uninteresting from the point of view of biosynthesis, the products of this chemistry come to rest as liquids and solids on the surface of Titan. There, they are protected from upper atmospheric sources of energy, but localized surface processes, including those associated with impact heating, might drive the chemistry in interesting directions with respect to polymer structures, chirality, and other signatures of advanced organic chemistry. The first step in assessing these possibilities will come in three years with the Cassini-Huygens mission. Beyond our solar system, giant planets in orbit around other stars are not directly targets of the search for life elsewhere (their natural satellites being unpromising targets in terms of detectability), but their presence implies important things about the habitability of Earth-like planets that might orbit the same stars. Giant planets affect the orbital stability and impact history of terrestrial planets, as well as the delivery of water and biogenic compounds to the surfaces of putative ``other Earths". Further, giant planets provide fertile ground for testing detection and characterization techniques. Thus, to maximize the chances of success in answering the fundamental questions of astrobiology, we must broaden both our minds and the targets we choose to explore. Some of the work described herein was supported by the Jet Propulsion Laboratory's DDF, and by the NASA Origins Program.

Mating Plugs in Polyandrous Giants: Which Sex Produces Them, When, How and Why?

PubMed Central

Kuntner, Matjaž; Kralj-Fišer, Simona; Li, Daiqin

2012-01-01

Background Males usually produce mating plugs to reduce sperm competition. However, females can conceivably also produce mating plugs in order to prevent unwanted, superfluous and energetically costly matings. In spiders–appropriate models for testing plugging biology hypotheses–mating plugs may consist of male genital parts and/or of amorphous covers consisting of glandular or sperm secretions. In the giant wood spider Nephila pilipes, a highly sexually dimorphic and polygamous species, males are known to produce ineffective embolic plugs through genital damage, but nothing is known about the origin and function of additional conspicuous amorphous plugs (AP) covering female genitals. Methodology We tested alternative hypotheses of the nature and function of AP in N. pilipes by staging mating trials with varying degrees of polyandry. No APs were ever formed during mating trials, which rules out the possibility of male AP formation. Instead, those females that oviposited produced the AP from a liquid secreted during egg sac formation. Polyandrous females were more likely to lay eggs and to produce the AP, as were those that mated longer and with more total insertions. Our further tests revealed that, in spite of being a side product of egg sac production, AP, when hardened, prevented any subsequent copulation. Conclusions We conclude that in the giant wood spider (Nephila pilipes), the amorphous mating plugs are not produced by the males, that repeated copulations (most likely polyandrous) are necessary for egg fertilization and AP formation, and that the AP represents a female adaptation to sexual conflict through prevention of unwanted, excessive copulations. Considering the largely unknown origin of amorphous plugs in spiders, we predict that a similar pattern might be detected in other clades, which would help elucidate the evolutionary interplay of various selection pressures responsible for the origin and maintenance of mating plugs. PMID:22829900

What made discy galaxies giant?

NASA Astrophysics Data System (ADS)

Saburova, A. S.

2018-01-01

I studied giant discy galaxies with optical radii more than 30 kpc. The comparison of these systems with discy galaxies of moderate sizes revealed that they tend to have higher rotation velocities, B-band luminosities, H I masses and dark-to-luminous mass ratios. The giant discs follow the trend log (M_{H I})(R_{25}) found for normal sized galaxies. It indicates the absence of the peculiarities of evolution of star formation in these galaxies. The H I mass-to-luminosity ratio of giant galaxies appears not to differ from that of normal-sized galaxies, giving evidence in favour of similar star formation efficiency. I also found that the bars and rings occur more frequently among giant discs. I performed mass modelling of the subsample of 18 giant galaxies with available rotation curves and surface photometry data and constructed χ2 maps for the parameters of their dark matter haloes. These estimates indicate that giant discs tend to be formed in larger more massive and rarified dark haloes in comparison to moderate-sized galaxies. However, giant galaxies do not deviate significantly from the relations between the optical sizes and dark halo parameters for moderate-sized galaxies. These findings can rule out the catastrophic scenario of the formation of at least most of giant discs, since they follow the same relations as normal discy galaxies. The giant sizes of the discs can be due to the high radial scale of the dark matter haloes in which they were formed.

Characterization and Analysis of Whole Transcriptome of Giant Panda Spleens: Implying Critical Roles of Long Non-Coding RNAs in Immunity.

PubMed

Peng, Rui; Liu, Yuliang; Cai, Zhigang; Shen, Fujun; Chen, Jiasong; Hou, Rong; Zou, Fangdong

2018-01-01

Giant pandas, an endangered species, are a powerful symbol of species conservation. Giant pandas may suffer from a variety of diseases. Owing to their highly specialized diet of bamboo, giant pandas are thought to have a relatively weak ability to resist diseases. The spleen is the largest organ in the lymphatic system. However, there is little known about giant panda spleen at a molecular level. Thus, clarifying the regulatory mechanisms of spleen could help us further understand the immune system of the giant panda as well as its conservation. The two giant panda spleens were from two male individuals, one newborn and one an adult, in a non-pathological condition. The whole transcriptomes of mRNA, lncRNA, miRNA, and circRNA in the two spleens were sequenced using the Illumina HiSeq platform. EBseq and IDEG6 were used to observe the differentially expressed genes (DEGs) between these two spleens. Gene Ontology and KEGG analyses were used to annotate the function of DEGs. Furthermore, networks between non-coding RNAs and protein-coding genes were constructed to investigate the relationship between non-coding RNAs and immune-associated genes. By comparative analysis of the whole transcriptomes of these two spleens, we found that one of the major roles of lncRNAs could be involved in the regulation of immune responses of giant panda spleens. In addition, our results also revealed that microRNAs and circRNAs may have evolved to regulate a large set of biological processes of giant panda spleens, and circRNAs may function as miRNA sponges. To our knowledge, this is the first report of lncRNAs and circRNAs in giant panda, which could be a useful resource for further giant panda research. Our study reveals the potential functional roles of miRNAs, lncRNAs, and circRNAs in giant panda spleen. © 2018 The Author(s). Published by S. Karger AG, Basel.

Central circuitry in the jellyfish Aglantha. II: The ring giant and carrier systems

PubMed

Mackie; Meech

1995-01-01

1. The ring giant axon in the outer nerve ring of the jellyfish Aglantha digitale is a multinucleate syncytium 85 % of which is occupied by an electron-dense fluid-filled vacuole apparently in a Gibbs­Donnan equilibrium with the surrounding band of cytoplasmic cortex. Micropipette recordings show small (-15 to -25 mV) and large (-62 to -66 mV) resting potentials. Low values, obtained with a high proportion of the micropipette penetrations, are assumed to be from the central vacuole; high values from the cytoplasmic cortex. Background electrical activity includes rhythmic oscillations and synaptic potentials representing hair cell input caused by vibration. 2. After the ring giant axon has been cut, propagating action potentials evoked by stimulation are conducted past the cut and re-enter the axon on the far side. The system responsible (the carrier system) through-conducts at a velocity approximately 25 % of that of the ring giant axon and is probably composed of small neurones running in parallel with it. Numerous small neurones are seen by electron microscopy, some making one-way and some two-way synapses with the ring giant. 3. Despite their different conduction velocities, the two systems normally appear to fire in synchrony and at the velocity of the ring giant axon. We suggest that, once initiated, ring giant spikes propagate rapidly around the margin, firing the carrier neurones through serial synapses and giving them, in effect, the same high conduction velocity. Initiation of ring giant spikes can, however, require input from the carrier system. The spikes are frequently seen to be mounted on slow positive potentials representing summed carrier postsynaptic potentials. 4. The carrier system fires one-for-one with the giant axons of the tentacles and may mediate impulse traffic between the latter and the ring giant axon. We suggest that the carrier system may also provide the pathways from the ring giant to the motor giant axons used in escape swimming. 5. The findings show that the ring giant axon functions in close collaboration with the carrier system, increasing the latter's effective conduction velocity, and that interactions with other neuronal sub-systems are probably mediated exclusively by the carrier system.

Infrared colours and inferred masses of metal-poor giant stars in the Keplerfield

NASA Astrophysics Data System (ADS)

Casey, A. R.; Kennedy, G. M.; Hartle, T. R.; Schlaufman, Kevin C.

2018-05-01

Intrinsically luminous giant stars in the Milky Way are the only potential volume-complete tracers of the distant disk, bulge, and halo. The chemical abundances of metal-poor giants also reflect the compositions of the earliest star-forming regions, providing the initial conditions for the chemical evolution of the Galaxy. However, the intrinsic rarity of metal-poor giants combined with the difficulty of efficiently identifying them with broad-band optical photometry has made it difficult to exploit them for studies of the Milky Way. One long-standing problem is that photometric selections for giant and/or metal-poor stars frequently include a large fraction of metal-rich dwarf contaminants. We re-derive a giant star photometric selection using existing public g-band and narrow-band DDO51photometry obtained in the Keplerfield. Our selection is simple and yields a contamination rate of main-sequence stars of ≲1% and a completeness of about 80 % for giant stars with Teff ≲ 5250 K - subject to the selection function of the spectroscopic surveys used to estimate these rates, and the magnitude range considered (11 ≲ g ≲ 15). While the DDO51filter is known to be sensitive to stellar surface gravity, we further show that the mid-infrared colours of DDO51-selected giants are strongly correlated with spectroscopic metallicity. This extends the infrared metal-poor selection developed by Schlaufman & Casey, demonstrating that the principal contaminants in their selection can be efficiently removed by the photometric separation of dwarfs and giants. This implies that any similarly efficient dwarf/giant discriminant (e.g., Gaiaparallaxes) can be used in conjunction with WISEcolours to select samples of giant stars with high completeness and low contamination. We employ our photometric selection to identify three metal-poor giant candidates in the Keplerfield with global asteroseismic parameters and find that masses inferred for these three stars using standard asteroseismic scaling relations are systematically over-estimated by 20-175%. Taken at face value, this small sample size implies that standard asteroseismic scaling relations over-predict stellar masses for metal-poor giant stars.

The Chemical Composition Contrast between M3 and M13 Revisited: New Abundances for 28 Giant Stars in M3

NASA Astrophysics Data System (ADS)

Sneden, Christopher; Kraft, Robert P.; Guhathakurta, Puragra; Peterson, Ruth C.; Fulbright, Jon P.

2004-04-01

We report new chemical abundances of 23 bright red giant members of the globular cluster M3, based on high-resolution (R~45,000) spectra obtained with the Keck I telescope. The observations, which involve the use of multislits in the HIRES Keck I spectrograph, are described in detail. Combining these data with a previously reported small sample of M3 giants obtained with the Lick 3 m telescope, we compare metallicities and [X/Fe] ratios for 28 M3 giants with a 35-star sample in the similar-metallicity cluster M13, and with Galactic halo field stars having [Fe/H]<-1. For elements having atomic number A>=A(Si), we derive little difference in [X/Fe] ratios in the M3, M13, or halo field samples. All three groups exhibit C depletion with advancing evolutionary state beginning at the level of the red giant branch ``bump,'' but the overall depletion of about 0.7-0.9 dex seen in the clusters is larger than that associated with the field stars. The behaviors of O, Na, Mg, and Al are distinctively different among the three stellar samples. Field halo giants and subdwarfs have a positive correlation of Na with Mg, as predicted from explosive or hydrostatic carbon burning in Type II supernova sites. Both M3 and M13 show evidence of high-temperature proton-capture synthesis from the ON, NeNa, and MgAl cycles, while there is no evidence for such synthesis among halo field stars. But the degree of such extreme proton-capture synthesis in M3 is smaller than it is in M13: the M3 giants exhibit only modest deficiencies of O and corresponding enhancements of Na, less extreme overabundances of Al, fewer stars with low Mg and correspondingly high Na, and no indication that O depletions are a function of advancing evolutionary state, as has been claimed for M13. We have also considered NGC 6752, for which Mg isotopic abundances have been reported by Yong et al. Giants in NGC 6752 and M13 satisfy the same anticorrelation of O abundances with the ratio (25Mg+26Mg)/24Mg, which measures the relative contribution of rare to abundant isotopes of Mg. This points to a scenario in which these abundance ratios arose in the ejected material of 3-6 Msolar cluster stars, material that was then used to form the atmospheres of the presently evolving low-mass cluster stars. It also suggests that the low oxygen abundance seen among the most evolved M13 giants arose in hot bottom O-to-N processing in these same intermediate-mass cluster stars. Thus, mixing is required by the dependence of some abundance ratios on luminosity, but an earlier nucleosynthesis process in a hotter environment than giants or main-sequence stars is required by the variations previously seen in stars near the main sequence. The nature and the site of the earlier process is constrained but not pinpointed by the observed Mg isotopic ratio. Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.

Dynamical hologram generation for high speed optical trapping of smart droplet microtools

PubMed Central

Lanigan, P. M. P.; Munro, I.; Grace, E. J.; Casey, D. R.; Phillips, J.; Klug, D. R.; Ces, O.; Neil, M. A. A.

2012-01-01

This paper demonstrates spatially selective sampling of the plasma membrane by the implementation of time-multiplexed holographic optical tweezers for Smart Droplet Microtools (SDMs). High speed (>1000fps) dynamical hologram generation was computed on the graphics processing unit of a standard display card and controlled by a user friendly LabView interface. Time multiplexed binary holograms were displayed in real time and mirrored to a ferroelectric Spatial Light Modulator. SDMs were manufactured with both liquid cores (as previously described) and solid cores, which confer significant advantages in terms of stability, polydispersity and ease of use. These were coated with a number of detergents, the most successful based upon lipids doped with transfection reagents. In order to validate these, trapped SDMs were maneuvered up to the plasma membrane of giant vesicles containing Nile Red and human biliary epithelial (BE) colon cancer cells with green fluorescent labeled protein (GFP)-labeled CAAX (a motif belonging to the Ras protein). Bright field and fluorescence images showed that successful trapping and manipulation of multiple SDMs in x, y, z was achieved with success rates of 30-50% and that subsequent membrane-SDM interactions led to the uptake of Nile Red or GFP-CAAX into the SDM. PMID:22808432

Re-impacting Debris Facilitated Cooling of the Lunar Magma Ocean

NASA Astrophysics Data System (ADS)

Perera, Viranga; Jackson, Alan; Elkins-Tanton, Linda T.; Asphaug, Erik

2017-10-01

It is widely believed that the Moon formed from the debris of a giant impact between the proto-Earth and a roughly Mars-sized body. Concomitant to this formation scenario, and also inferred from geochemical analyses of Apollo samples, is the past existence of a Lunar Magma Ocean (LMO). After about 80% of the LMO solidified, it is believed that the mineral plagioclase would have become stable and crystallized out of the LMO. Rocks that formed principally of plagioclase would have been buoyant in the residual liquid and thus helped form a floatation crust that acted as a thermally conductive blanket over the LMO. Previous modelling work found that the LMO would have solidified in about 10 Myr. However, studies have shown that, during the giant impact event, a large quantity of debris (totaling over a Lunar mass) would have been released that was not immediately incorporated into the Earth and the Moon. This material would have subsequently re-impacted the Earth and the Moon. Particularly for the Moon, this debris would have punctured holes into the nascent lunar crust, attenuated its thermal blanketing effect, and thus facilitated the cooling of the LMO. We improve upon previous studies of the solidification of the LMO by incorporating this re-impacting debris, and find that the re-impacting debris may have reduced the LMO solidification time.

Magnetic Field Sensors Based on Giant Magnetoresistance (GMR) Technology: Applications in Electrical Current Sensing

PubMed Central

Reig, Candid; Cubells-Beltran, María-Dolores; Muñoz, Diego Ramírez

2009-01-01

The 2007 Nobel Prize in Physics can be understood as a global recognition to the rapid development of the Giant Magnetoresistance (GMR), from both the physics and engineering points of view. Behind the utilization of GMR structures as read heads for massive storage magnetic hard disks, important applications as solid state magnetic sensors have emerged. Low cost, compatibility with standard CMOS technologies and high sensitivity are common advantages of these sensors. This way, they have been successfully applied in a lot different environments. In this work, we are trying to collect the Spanish contributions to the progress of the research related to the GMR based sensors covering, among other subjects, the applications, the sensor design, the modelling and the electronic interfaces, focusing on electrical current sensing applications. PMID:22408486

Four new planets around giant stars and the mass-metallicity correlation of planet-hosting stars

NASA Astrophysics Data System (ADS)

Jones, M. I.; Jenkins, J. S.; Brahm, R.; Wittenmyer, R. A.; Olivares E., F.; Melo, C. H. F.; Rojo, P.; Jordán, A.; Drass, H.; Butler, R. P.; Wang, L.

2016-05-01

Context. Exoplanet searches have revealed interesting correlations between the stellar properties and the occurrence rate of planets. In particular, different independent surveys have demonstrated that giant planets are preferentially found around metal-rich stars and that their fraction increases with the stellar mass. Aims: During the past six years we have conducted a radial velocity follow-up program of 166 giant stars to detect substellar companions and to characterize their orbital properties. Using this information, we aim to study the role of the stellar evolution in the orbital parameters of the companions and to unveil possible correlations between the stellar properties and the occurrence rate of giant planets. Methods: We took multi-epoch spectra using FEROS and CHIRON for all of our targets, from which we computed precision radial velocities and derived atmospheric and physical parameters. Additionally, velocities computed from UCLES spectra are presented here. By studying the periodic radial velocity signals, we detected the presence of several substellar companions. Results: We present four new planetary systems around the giant stars HIP 8541, HIP 74890, HIP 84056, and HIP 95124. Additionally, we study the correlation between the occurrence rate of giant planets with the stellar mass and metallicity of our targets. We find that giant planets are more frequent around metal-rich stars, reaching a peak in the detection of f = 16.7+15.5-5.9% around stars with [Fe/H] ~ 0.35 dex. Similarly, we observe a positive correlation of the planet occurrence rate with the stellar mass, between M⋆ ~ 1.0 and 2.1 M⊙, with a maximum of f = 13.0+10.1-4.2% at M⋆ = 2.1 M⊙. Conclusions: We conclude that giant planets are preferentially formed around metal-rich stars. In addition, we conclude that they are more efficiently formed around more massive stars, in the stellar mass range of ~1.0-2.1 M⊙. These observational results confirm previous findings for solar-type and post-MS hosting stars, and provide further support to the core-accretion formation model. Based on observations collected at La Silla - Paranal Observatory under programs IDs 085.C-0557, 087.C.0476, 089.C-0524, 090.C-0345 and through the Chilean Telescope Time under programs IDs CN 12A-073, CN 12B-047, CN 13A-111, CN 13B-51, CN 14A-52, CN-15A-48, and CN-15B-25.

Microsurgical management of basilar artery apex aneurysms: a single surgeon's experience from Louisiana State University, Shreveport.

PubMed

Nanda, Anil; Sonig, Ashish; Banerjee, Anirban Deep; Javalkar, Vijay Kumar

2014-01-01

Basilar artery apex aneurysms continue to generate technical challenges and management controversy. Endovascular intervention is becoming the mainstay in the management of these formidable aneurysms, but it has limitations, especially with large/giant or wide neck basilar apex aneurysms. There is paucity of data in the available literature pertaining to the successful management of large/giant, wide neck, and calcified/thrombosed basilar apex aneurysms. We present our experience with consecutively operated complex basilar apex aneurysms so as to present the role of microneurosurgery as a viable management option for these aneurysms. Ours is a retrospective analysis of case-records for operated cases of basilar artery aneurysms spanning 18 years. Basilar apex aneurysms >10 cm, calcified or thrombosed, neck ≥4 mm posterior direction, and retro/subsellar were considered as complex anatomy aneurysms. Basilar apex aneurysms with favorable anatomy were included in the study as a reference group for statistical analysis. Patient demographics, complex features of aneurysms, clinical grade, and outcomes were analyzed. A total of 33 (53.2%) patients had complex anatomy: large (>10 mm) in eight (24.2%); giant aneurysms (>25 mm) in seven (21.2%); wide-neck in 22 (66.7%); and calcified/thrombosed morphology in five (15.1%). The mean age was 48.5 years, and 22 (66.67%) were women. All aneurysms were clipped by the use of various skull base approaches. A total of 71.9% of patients harboring complex aneurysm had good outcomes. If only unruptured and good grade complex aneurysms also are considered, then 86.9% (n = 20) patients had good outcomes. Statistically there was no significant difference in the outcomes of complex and noncomplex aneurysm. Although concerning, the management of large/giant, wide neck, and calcified/thrombosed aneurysms with microneurosurgery is still a competitive alternative to endovascular therapy. After careful selection of appropriate skull base approaches based on the complexity of the basilar apex aneurysm, microneurosurgery can achieve acceptable results. Copyright © 2014 Elsevier Inc. All rights reserved.

KELT-12b: A P ˜ 5 day, Highly Inflated Hot Jupiter Transiting a Mildly Evolved Hot Star

NASA Astrophysics Data System (ADS)

Stevens, Daniel J.; Collins, Karen A.; Gaudi, B. Scott; Beatty, Thomas G.; Siverd, Robert J.; Bieryla, Allyson; Fulton, Benjamin J.; Crepp, Justin R.; Gonzales, Erica J.; Coker, Carl T.; Penev, Kaloyan; Stassun, Keivan G.; Jensen, Eric L. N.; Howard, Andrew W.; Latham, David W.; Rodriguez, Joseph E.; Zambelli, Roberto; Bozza, Valerio; Reed, Phillip A.; Gregorio, Joao; Buchhave, Lars A.; Penny, Matthew T.; Pepper, Joshua; Berlind, Perry; Calchi Novati, Sebastiano; Calkins, Michael L.; D'Ago, Giuseppe; Eastman, Jason D.; Bayliss, D.; Colón, Knicole D.; Curtis, Ivan A.; DePoy, D. L.; Esquerdo, Gilbert A.; Gould, Andrew; Joner, Michael D.; Kielkopf, John F.; Labadie-Bartz, Jonathan; Lund, Michael B.; Manner, Mark; Marshall, Jennifer L.; McLeod, Kim K.; Oberst, Thomas E.; Pogge, Richard W.; Scarpetta, Gaetano; Stephens, Denise C.; Stockdale, Christopher; Tan, T. G.; Trueblood, Mark; Trueblood, Patricia

2017-04-01

We announce the discovery of KELT-12b, a highly inflated Jupiter-mass planet transiting the mildly evolved, V = 10.64 host star TYC 2619-1057-1. We followed up the initial transit signal in the KELT-North survey data with precise ground-based photometry, high-resolution spectroscopy, precise radial velocity measurements, and high-resolution adaptive optics imaging. Our preferred best-fit model indicates that the host star has {T}{eff} = 6279 ± 51 K, {log}{g}\\star = 3.89 ± 0.05, [Fe/H] = {0.19}-0.09+0.08, {M}* = {1.59}-0.09+0.07 {M}⊙ , and {R}* = 2.37 ± 0.17 {R}⊙ . The planetary companion has {M}{{P}} = 0.95 ± 0.14 {M}{{J}}, {R}{{P}} = {1.78}-0.16+0.17 {R}{{J}}, {log}{g}{{P}} = {2.87}-0.10+0.09, and density {ρ }{{P}} = {0.21}-0.05+0.07 g cm-3, making it one of the most inflated giant planets known. Furthermore, for future follow-up, we report a high-precision time of inferior conjunction in {{BJD}}{TDB} of 2,457,083.660459 ± 0.000894 and period of P=5.0316216+/- 0.000032 days. Despite the relatively large separation of ˜0.07 au implied by its ˜5.03-day orbital period, KELT-12b receives significant flux of {2.38}-0.29+0.32× {10}9 erg s-1 cm-2 from its host. We compare the radii and insolations of transiting gas giant planets around hot ({T}{eff}≥slant 6250 K) and cool stars, noting that the observed paucity of known transiting giants around hot stars with low insolation is likely due to selection effects. We underscore the significance of long-term ground-based monitoring of hot stars and space-based targeting of hot stars with the Transiting Exoplanet Survey Satellite to search for inflated gas giants in longer-period orbits.

77 FR 28496 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-15

... daily retention limit would be the default retention limit of one large medium or giant BFT (measuring... default level of one large medium or giant BFT as follows: Two large medium or giant BFT for the January subquota period (75 FR 79309, December 20, 2010); three large medium or giant BFT for June through November...

Habitat use by giant panda in relation to man-made forest in Wanglang Nature Reserve of China.

PubMed

Kang, Dongwei; Wang, Xiaorong; Yang, Hongwei; Duan, Lijuan; Li, Junqing

2014-12-01

To evaluate the effectiveness of human restoration in species conservation, in this study, we undertook a field survey of giant panda (Ailuropoda melanoleuca) habitat and man-made forest habitat in Wanglang Nature Reserve of China. Our results revealed that giant panda did not use the man-made forest in this area so far, and that there were significant differences between the giant panda habitat and the man-made forest habitat. Compared with giant panda habitat, the man-made forest habitat was characterized by lower shrub coverage, thinner trees and lower bamboo density. To improve the effectiveness of human restoration, the habitat requirement of giant panda should be fully consider in the whole process of habitat restoration.

Monitoring of a Southern Giant Petrel Macronectes giganteus population on the Frazier Islands, Wilkes Land, Antarctica

USGS Publications Warehouse

Creuwels, J.C.S.; Stark, J.S.; Woehler, Eric J.; Van Franeker, J. A.; Ribic, C.A.

2005-01-01

Since 1956, Southern Giant Petrels on the Frazier Islands, East Antarctica, have been counted with different census techniques, sometimes varying within seasons and among islands, which hindered analysis of the data. Protective measures for the islands from 1986 onwards have increased the need for reliable long-term census data, but reduced the ways to collect these data. Published and unpublished data were re-examined, and population trends were reconstructed based on two relatively standardised techniques: the number of active chicks (AC) and the number of apparently occupied nests (AON) around hatching. AC-values from Nelly Island from 1959 to 1998 indicate substantial periodic fluctuations, but no consistent long-term change. Since the late 1970s, AC-values on the other two islands and AON-values suggest that the breeding population may have grown by 35%. This recent growth, however, is within the extent of periodic fluctuations observed in Southern Giant Petrel population that is stable over the long term. ?? Springer-Verlag 2004.

Mid-infrared metamaterial based on perforated SiC membrane: engineering optical response using surface phonon polaritons

NASA Astrophysics Data System (ADS)

Korobkin, D.; Urzhumov, Y. A.; Neuner, B., III; Zorman, C.; Zhang, Z.; Mayergoyz, I. D.; Shvets, G.

2007-09-01

We theoretically and experimentally study electromagnetic properties of a novel mid-infrared metamaterial: optically thin silicon carbide (SiC) membrane perforated by an array of sub-wavelength holes. Giant absorption and transmission is found using Fourier transformed infrared (FTIR) microscopy and explained by introducing a frequency-dependent effective permittivity ɛeff(ω) of the perforated film. The value of ɛeff(ω) is determined by the excitation of two distinct types of hole resonances: delocalized slow surface polaritons (SSPs) whose frequencies are largely determined by the array period, and a localized surface polariton (LSP) corresponding to the resonance of an isolated hole. Only SSPs are shown to modify ɛeff(ω) strongly enough to cause giant transmission and absorption. Because of the sub-wavelength period of the hole array, anomalous optical properties can be directly traced to surface polaritons, and their interpretation is not obscured by diffractive effects. Giant absorbance of this metamaterial can be utilized in designing highly efficient thermal radiation sources.

VizieR Online Data Catalog: Properties of giant arcs behind CLASH clusters (Xu+, 2016)

NASA Astrophysics Data System (ADS)

Xu, B.; Postman, M.; Meneghetti, M.; Seitz, S.; Zitrin, A.; Merten, J.; Maoz, D.; Frye, B.; Umetsu, K.; Zheng, W.; Bradley, L.; Vega, J.; Koekemoer, A.

2018-01-01

Giant arcs are found in the CLASH images and in simulated images that mimic the CLASH data, using an efficient automated arc-finding algorithm whose selection function has been carefully quantified. CLASH is a 524-orbit multicycle treasury program that targeted 25 massive clusters with 0.18=6.5 in 20 X-ray-selected CLASH clusters. After applying our minimum arc length criterion l>=6", the arc count drops to 81 giant arcs selected from the 20 X-ray-selected CLASH clusters. (2 data files).

Planetary Formation: From The Earth And Moon To Extrasolar Planets

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

1999-01-01

An overview of current theories of planetary growth, emphasizing the formation of habitable planets, is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost - to orbital decay within the protoplanetary disk. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but if they become massive enough before the protoplanetary disk dissipates, then they are able to accumulate substantial amounts of gas. Specific issues to be discussed include: (1) how do giant planets influence the formation and habitability of terrestrial planets? (2) could a giant impact leading to lunar formation have occurred - 100 million years after the condensation of the oldest meteorites?

The Formation of the Earth-Moon System and the Planets

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

1998-01-01

An overview of current theories of star and planet formation, with emphasis on terrestrial planet accretion and the formation of the Earth-Moon system is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant impacts during the final stages of growth can produce large planetary satellites, such as Earth's Moon. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

Giant microwave-induced B -periodic magnetoresistance oscillations in a two-dimensional electron gas with a bridged-gate tunnel point contact

NASA Astrophysics Data System (ADS)

Levin, A. D.; Mikhailov, S. A.; Gusev, G. M.; Kvon, Z. D.; Rodyakina, E. E.; Latyshev, A. V.

2017-02-01

We have studied the magnetoresistance of a quantum point contact fabricated on a high mobility two-dimensional electron gas (2DEG) exposed to microwave irradiation. The resistance reveals giant B -periodic oscillations with a relative amplitude Δ R /R of up to 700 % resulting from the propagation and interference of the edge magnetoplasmons (EMPs) in the sample. This giant photoconductance is attributed to the considerably large local electron density modulation in the vicinity of the point contact. We have also analyzed the oscillation periods Δ B of the resistance oscillations and, comparing the data with the EMP theory, extracted the EMP interference length L . We have found that the length L substantially exceeds the distance between the contact leads, and rather corresponds to the distance between metallic contact pads measured along the edge of the 2DEG. This resolves existing controversy in the literature and should help to properly design highly sensitive microwave and terahertz spectrometers based on the discussed effect.

Transport properties of high-performance all-Heusler Co2CrSi/Cu2CrAl/Co2CrSi giant magnetoresistance device

NASA Astrophysics Data System (ADS)

Bai, Z. Q.; Lu, Y. H.; Shen, L.; Ko, V.; Han, G. C.; Feng, Y. P.

2012-05-01

Transport properties of giant magnetoresistance (MR) junction consisting of trilayer Co2CrSi/Cu2CrAl/Co2CrSi Heusler alloys (L21) are studied using first-principles approach based on density functional theory and the non-equilibrium Green's function method. Highly conductive channels are found in almost the entire k-plane when the magnetizations of the electrodes are parallel, while they are completely blocked in the antiparallel configuration, which leads to a high magnetoresistance ratio (the pessimistic MR ratio is nearly 100%). Furthermore, the calculated I-V curve shows that the device behaves as a good spin valve with a considerable disparity in currents under the parallel and antiparallel magnetic configurations of the electrodes. The Co2CrSi/Cu2CrAl/Co2CrSi junction could be useful for high-performance all-metallic current-perpendicular-to-plane giant magnetoresistance reading head for the next generation high density magnetic storage.

The Expanding Family of Virophages

PubMed Central

Bekliz, Meriem; Colson, Philippe; La Scola, Bernard

2016-01-01

Virophages replicate with giant viruses in the same eukaryotic cells. They are a major component of the specific mobilome of mimiviruses. Since their discovery in 2008, five other representatives have been isolated, 18 new genomes have been described, two of which being nearly completely sequenced, and they have been classified in a new viral family, Lavidaviridae. Virophages are small viruses with approximately 35–74 nm large icosahedral capsids and 17–29 kbp large double-stranded DNA genomes with 16–34 genes, among which a very small set is shared with giant viruses. Virophages have been isolated or detected in various locations and in a broad range of habitats worldwide, including the deep ocean and inland. Humans, therefore, could be commonly exposed to virophages, although currently limited evidence exists of their presence in humans based on serology and metagenomics. The distribution of virophages, the consequences of their infection and the interactions with their giant viral hosts within eukaryotic cells deserve further research. PMID:27886075

Giant nonlinear interaction between two optical beams via a quantum dot embedded in a photonic wire

NASA Astrophysics Data System (ADS)

Nguyen, H. A.; Grange, T.; Reznychenko, B.; Yeo, I.; de Assis, P.-L.; Tumanov, D.; Fratini, F.; Malik, N. S.; Dupuy, E.; Gregersen, N.; Auffèves, A.; Gérard, J.-M.; Claudon, J.; Poizat, J.-Ph.

2018-05-01

Optical nonlinearities usually appear for large intensities, but discrete transitions allow for giant nonlinearities operating at the single-photon level. This has been demonstrated in the last decade for a single optical mode with cold atomic gases, or single two-level systems coupled to light via a tailored photonic environment. Here, we demonstrate a two-mode giant nonlinearity with a single semiconductor quantum dot (QD) embedded in a photonic wire antenna. We exploit two detuned optical transitions associated with the exciton-biexciton QD level scheme. Owing to the broadband waveguide antenna, the two transitions are efficiently interfaced with two free-space laser beams. The reflection of one laser beam is then controlled by the other beam, with a threshold power as low as 10 photons per exciton lifetime (1.6 nW ). Such a two-color nonlinearity opens appealing perspectives for the realization of ultralow-power logical gates and optical quantum gates, and could also be implemented in an integrated photonic circuit based on planar waveguides.

International Registry for Patients With Castleman Disease

ClinicalTrials.gov

2017-07-12

Castleman Disease; Castleman's Disease; Giant Lymph Node Hyperplasia; Angiofollicular Lymph Hyperplasia; Angiofollicular Lymph Node Hyperplasia; Angiofollicular Lymphoid Hyperplasia; GLNH; Hyperplasia, Giant Lymph Node; Lymph Node Hyperplasia, Giant

Transcriptomic Profiling of Differential Responses to Drought in Two Freshwater Mussel Species, the Giant Floater Pyganodon grandis and the Pondhorn Uniomerus tetralasmus

PubMed Central

Landis, Andrew Gascho; Wang, Guiling; Stoeckel, James; Peatman, Eric

2014-01-01

The southeastern US has experienced recurrent drought during recent decades. Increasing demand for water, as precipitation decreases, exacerbates stress on the aquatic biota of the Southeast: a global hotspot for freshwater mussel, crayfish, and fish diversity. Freshwater unionid mussels are ideal candidates to study linkages between ecophysiological and behavioral responses to drought. Previous work on co-occurring mussel species suggests a coupling of physiology and behavior along a gradient ranging from intolerant species such as Pyganodon grandis (giant floater) that track receding waters and rarely burrow in the substrates to tolerant species such as Uniomerus tetralasmus (pondhorn) that rarely track receding waters, but readily burrow into the drying sediments. We utilized a next-generation sequencing-based RNA-Seq approach to examine heat/desiccation-induced transcriptomic profiles of these two species in order to identify linkages between patterns of gene expression, physiology and behavior. Sequencing produced over 425 million 100 bp reads. Using the de novo assembly package Trinity, we assembled the short reads into 321,250 contigs from giant floater (average length 835 bp) and 385,735 contigs from pondhorn (average length 929 bp). BLAST-based annotation and gene expression analysis revealed 2,832 differentially expressed genes in giant floater and 2,758 differentially expressed genes in pondhorn. Trancriptomic responses included changes in molecular chaperones, oxidative stress profiles, cell cycling, energy metabolism, immunity, and cytoskeletal rearrangements. Comparative analyses between species indicated significantly higher induction of molecular chaperones and cytoskeletal elements in the intolerant P. grandis as well as important differences in genes regulating apoptosis and immunity. PMID:24586812

The normal vaginal and uterine bacterial microbiome in giant pandas (Ailuropoda melanoleuca).

PubMed

Yang, Xin; Cheng, Guangyang; Li, Caiwu; Yang, Jiang; Li, Jianan; Chen, Danyu; Zou, Wencheng; Jin, SenYan; Zhang, Hemin; Li, Desheng; He, Yongguo; Wang, Chengdong; Wang, Min; Wang, Hongning

2017-06-01

While the health effects of the colonization of the reproductive tracts of mammals by bacterial communities are widely known, there is a dearth of knowledge specifically in relation to giant panda microbiomes. In order to investigate the vaginal and uterine bacterial diversity of healthy giant pandas, we used high-throughput sequence analysis of portions of the 16S rRNA gene, based on samples taken from the vaginas (GPV group) and uteri (GPU group) of these animals. Results showed that the four most abundant phyla, which contained in excess of 98% of the total sequences, were Proteobacteria (59.2% for GPV and 51.4% for GPU), Firmicutes (34.4% for GPV and 23.3% for GPU), Actinobacteria (5.2% for GPV and 14.0% for GPU) and Bacteroidetes (0.3% for GPV and 10.3% for GPU). At the genus level, Escherichia was most abundant (11.0%) in the GPV, followed by Leuconostoc (8.7%), Pseudomonas (8.0%), Acinetobacter (7.3%), Streptococcus (6.3%) and Lactococcus (6.0%). In relation to the uterine samples, Janthinobacterium had the highest prevalence rate (20.2%), followed by Corynebacterium (13.2%), Streptococcus (19.6%), Psychrobacter (9.3%), Escherichia (7.5%) and Bacteroides (6.2%). Moreover, both Chao1 and abundance-based coverage estimator (ACE) species richness indices, which were operating at the same sequencing depth for each sample, demonstrated that GPV had more species richness than GPU, while Simpson and Shannon indices of diversity indicated that GPV had the higher bacterial diversity. These findings contribute to our understanding of the potential influence abnormal reproductive tract microbial communities have on negative pregnancy outcomes in giant pandas. Copyright © 2017 Elsevier GmbH. All rights reserved.

Extensive Broadband X-Ray Monitoring During the Formation of a Giant Radio Jet Base in Cyg X-3 with AstroSat

NASA Astrophysics Data System (ADS)

Pahari, Mayukh; Yadav, J. S.; Verdhan Chauhan, Jai; Rawat, Divya; Misra, Ranjeev; Agrawal, P. C.; Chandra, Sunil; Bagri, Kalyani; Jain, Pankaj; Manchanda, R. K.; Chitnis, Varsha; Bhattacharyya, Sudip

2018-01-01

We present X-ray spectral and timing behavior of Cyg X-3 as observed by AstroSat during the onset of a giant radio flare on 2017 April 1–2. Within a timescale of a few hours, the source shows a transition from the hypersoft state (HPS) to a more luminous state (we termed as the very high state), which coincides with the time of the steep rise in radio flux density by an order of magnitude. Modeling the Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC) spectra jointly in 0.5–70.0 keV, we found that the first few hours of the observation is dominated by the HPS with no significant counts above 17 keV. Later, an additional flat power-law component suddenly appeared in the spectra that extends to very high energies with the power-law photon index of {1.49}-0.03+0.04. Such a flat power-law component has never been reported from Cyg X-3. Interestingly the fitted power-law model in 25–70 keV, when extrapolated to the radio frequency, predicts the radio flux density to be consistent with the trend measured from the RATAN-600 telescope at 11.2 GHz. This provides direct evidence of the synchrotron origin of flat X-ray power-law component and the most extensive monitoring of the broadband X-ray behavior at the moment of decoupling the giant radio jet base from the compact object in Cyg X-3. Using SXT and LAXPC observations, we determine the giant flare ejection time as MJD 57845.34 ± 0.08 when 11.2 GHz radio flux density increases from ∼100 to ∼478 mJy.

Kepler-432 b: a massive warm Jupiter in a 52-day eccentric orbit transiting a giant star

NASA Astrophysics Data System (ADS)

Ortiz, Mauricio; Gandolfi, Davide; Reffert, Sabine; Quirrenbach, Andreas; Deeg, Hans J.; Karjalainen, Raine; Montañés-Rodríguez, Pilar; Nespral, David; Nowak, Grzegorz; Osorio, Yeisson; Palle, Enric

2015-01-01

We study the Kepler object Kepler-432, an evolved star ascending the red giant branch. By deriving precise radial velocities from multi-epoch high-resolution spectra of Kepler-432 taken with the CAFE spectrograph at the 2.2 m telescope of Calar Alto Observatory and the FIES spectrograph at the Nordic Optical Telescope of Roque de Los Muchachos Observatory, we confirm the planetary nature of the object Kepler-432 b, which has a transit period of 52 days. We find a planetary mass of Mp = 5.84 ± 0.05MJup and a high eccentricity of e = 0.478 ± 0.004. With a semi-major axis of a = 0.303 ± 0.007 AU, Kepler-432 b is the first bona fide warm Jupiter detected to transit a giant star. We also find a radial velocity linear trend of γ˙ = 0.44 ± 0.04 m s-1 d-1, which suggests the presence of a third object in the system. Current models of planetary evolution in the post-main-sequence phase predict that Kepler-432 b will be most likely engulfed by its host star before the latter reaches the tip of the red giant branch. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie (Heidelberg) and the Instituto de Astrofísica de Andalucía (IAA-CSIC, Granada).Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.Table 3 is available in electronic form at http://www.aanda.org

Patterns of Adaptive and Neutral Diversity Identify the Xiaoxiangling Mountains as a Refuge for the Giant Panda

PubMed Central

Wan, Qiu-Hong; Lou, Ji-Kang; Li, Wen-Jing; Ge, Yun-Fa; Fang, Sheng-Guo

2013-01-01

Genetic variation plays a significant role in maintaining the evolutionary potential of a species. Comparing the patterns of adaptive and neutral diversity in extant populations is useful for understanding the local adaptations of a species. In this study, we determined the fine-scale genetic structure of 6 extant populations of the giant panda (Ailuropoda melanoleuca) using mtDNA and DNA fingerprints, and then overlaid adaptive variations in 6 functional Aime-MHC class II genes (DRA, DRB3, DQA1, DQA2, DQB1, and DQB2) on this framework. We found that: (1) analysis of the mtDNA and DNA fingerprint-based networks of the 6 populations identified the independent evolutionary histories of the 2 panda subspecies; (2) the basal (ancestral) branches of the fingerprint-based Sichuan-derived network all originated from the smallest Xiaoxiangling (XXL) population, suggesting the status of a glacial refuge in XXL; (3) the MHC variations among the tested populations showed that the XXL population exhibited extraordinary high levels of MHC diversity in allelic richness, which is consistent with the diversity characteristics of a glacial refuge; (4) the phylogenetic tree showed that the basal clades of giant panda DQB sequences were all occupied by XXL-specific sequences, providing evidence for the ancestor-resembling traits of XXL. Finally, we found that the giant panda had many more DQ alleles than DR alleles (33∶13), contrary to other mammals, and that the XXL refuge showed special characteristics in the DQB loci, with 7 DQB members of 9 XXL-unique alleles. Thus, this study identified XXL as a glacial refuge, specifically harboring the most number of primitive DQB alleles. PMID:23894623

Patterns of adaptive and neutral diversity identify the Xiaoxiangling mountains as a refuge for the giant panda.

PubMed

Chen, Yi-Yan; Zhu, Ying; Wan, Qiu-Hong; Lou, Ji-Kang; Li, Wen-Jing; Ge, Yun-Fa; Fang, Sheng-Guo

2013-01-01

Genetic variation plays a significant role in maintaining the evolutionary potential of a species. Comparing the patterns of adaptive and neutral diversity in extant populations is useful for understanding the local adaptations of a species. In this study, we determined the fine-scale genetic structure of 6 extant populations of the giant panda (Ailuropoda melanoleuca) using mtDNA and DNA fingerprints, and then overlaid adaptive variations in 6 functional Aime-MHC class II genes (DRA, DRB3, DQA1, DQA2, DQB1, and DQB2) on this framework. We found that: (1) analysis of the mtDNA and DNA fingerprint-based networks of the 6 populations identified the independent evolutionary histories of the 2 panda subspecies; (2) the basal (ancestral) branches of the fingerprint-based Sichuan-derived network all originated from the smallest Xiaoxiangling (XXL) population, suggesting the status of a glacial refuge in XXL; (3) the MHC variations among the tested populations showed that the XXL population exhibited extraordinary high levels of MHC diversity in allelic richness, which is consistent with the diversity characteristics of a glacial refuge; (4) the phylogenetic tree showed that the basal clades of giant panda DQB sequences were all occupied by XXL-specific sequences, providing evidence for the ancestor-resembling traits of XXL. Finally, we found that the giant panda had many more DQ alleles than DR alleles (33∶13), contrary to other mammals, and that the XXL refuge showed special characteristics in the DQB loci, with 7 DQB members of 9 XXL-unique alleles. Thus, this study identified XXL as a glacial refuge, specifically harboring the most number of primitive DQB alleles.

Squid Giant Axon Contains Neurofilament Protein mRNA but does not Synthesize Neurofilament Proteins.

PubMed

Gainer, Harold; House, Shirley; Kim, Dong Sun; Chin, Hemin; Pant, Harish C

2017-04-01

When isolated squid giant axons are incubated in radioactive amino acids, abundant newly synthesized proteins are found in the axoplasm. These proteins are translated in the adaxonal Schwann cells and subsequently transferred into the giant axon. The question as to whether any de novo protein synthesis occurs in the giant axon itself is difficult to resolve because the small contribution of the proteins possibly synthesized intra-axonally is not easily distinguished from the large amounts of the proteins being supplied from the Schwann cells. In this paper, we reexamine this issue by studying the synthesis of endogenous neurofilament (NF) proteins in the axon. Our laboratory previously showed that NF mRNA and protein are present in the squid giant axon, but not in the surrounding adaxonal glia. Therefore, if the isolated squid axon could be shown to contain newly synthesized NF protein de novo, it could not arise from the adaxonal glia. The results of experiments in this paper show that abundant 3H-labeled NF protein is synthesized in the squid giant fiber lobe containing the giant axon's neuronal cell bodies, but despite the presence of NF mRNA in the giant axon no labeled NF protein is detected in the giant axon. This lends support to the glia-axon protein transfer hypothesis which posits that the squid giant axon obtains newly synthesized protein by Schwann cell transfer and not through intra-axonal protein synthesis, and further suggests that the NF mRNA in the axon is in a translationally repressed state.

THE REDSHIFT DISTRIBUTION OF GIANT ARCS IN THE SLOAN GIANT ARCS SURVEY

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

Bayliss, Matthew B.; Gladders, Michael D.; Koester, Benjamin P.

2011-01-20

We measure the redshift distribution of a sample of 28 giant arcs discovered as a part of the Sloan Giant Arcs Survey. Gemini/GMOS-North spectroscopy provides precise redshifts for 24 arcs, and 'redshift desert' constrains for the remaining 4 arcs. This is a direct measurement of the redshift distribution of a uniformly selected sample of bright giant arcs, which is an observable that can be used to inform efforts to predict giant arc statistics. Our primary giant arc sample has a median redshift z = 1.821 and nearly two-thirds of the arcs, 64%, are sources at z {approx}> 1.4, indicating thatmore » the population of background sources that are strongly lensed into bright giant arcs resides primarily at high redshift. We also analyze the distribution of redshifts for 19 secondary strongly lensed background sources that are not visually apparent in Sloan Digital Sky Survey imaging, but were identified in deeper follow-up imaging of the lensing cluster fields. Our redshift sample for the secondary sources is not spectroscopically complete, but combining it with our primary giant arc sample suggests that a large fraction of all background galaxies that are strongly lensed by foreground clusters reside at z {approx}> 1.4. Kolmogorov-Smirnov tests indicate that our well-selected, spectroscopically complete primary giant arc redshift sample can be reproduced with a model distribution that is constructed from a combination of results from studies of strong-lensing clusters in numerical simulations and observational constraints on the galaxy luminosity function.« less

EFFECTS OF DYNAMICAL EVOLUTION OF GIANT PLANETS ON SURVIVAL OF TERRESTRIAL PLANETS

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

Matsumura, Soko; Ida, Shigeru; Nagasawa, Makiko

2013-04-20

The orbital distributions of currently observed extrasolar giant planets allow marginally stable orbits for hypothetical, terrestrial planets. In this paper, we propose that many of these systems may not have additional planets on these ''stable'' orbits, since past dynamical instability among giant planets could have removed them. We numerically investigate the effects of early evolution of multiple giant planets on the orbital stability of the inner, sub-Neptune-like planets which are modeled as test particles, and determine their dynamically unstable region. Previous studies have shown that the majority of such test particles are ejected out of the system as a resultmore » of close encounters with giant planets. Here, we show that secular perturbations from giant planets can remove test particles at least down to 10 times smaller than their minimum pericenter distance. Our results indicate that, unless the dynamical instability among giant planets is either absent or quiet like planet-planet collisions, most test particles down to {approx}0.1 AU within the orbits of giant planets at a few AU may be gone. In fact, out of {approx}30% of survived test particles, about three quarters belong to the planet-planet collision cases. We find a good agreement between our numerical results and the secular theory, and present a semi-analytical formula which estimates the dynamically unstable region of the test particles just from the evolution of giant planets. Finally, our numerical results agree well with the observations, and also predict the existence of hot rocky planets in eccentric giant planet systems.« less

Assessing vulnerability of giant pandas to climate change in the Qinling Mountains of China.

PubMed

Li, Jia; Liu, Fang; Xue, Yadong; Zhang, Yu; Li, Diqiang

2017-06-01

Climate change might pose an additional threat to the already vulnerable giant panda ( Ailuropoda melanoleuca ). Effective conservation efforts require projections of vulnerability of the giant panda in facing climate change and proactive strategies to reduce emerging climate-related threats. We used the maximum entropy model to assess the vulnerability of giant panda to climate change in the Qinling Mountains of China. The results of modeling included the following findings: (1) the area of suitable habitat for giant pandas was projected to decrease by 281 km 2 from climate change by the 2050s; (2) the mean elevation of suitable habitat of giant panda was predicted to shift 30 m higher due to climate change over this period; (3) the network of nature reserves protect 61.73% of current suitable habitat for the species, and 59.23% of future suitable habitat; (4) current suitable habitat mainly located in Chenggu, Taibai, and Yangxian counties (with a total area of 987 km 2 ) was predicted to be vulnerable. Assessing the vulnerability of giant panda provided adaptive strategies for conservation programs and national park construction. We proposed adaptation strategies to ameliorate the predicted impacts of climate change on giant panda, including establishing and adjusting reserves, establishing habitat corridors, improving adaptive capacity to climate change, and strengthening monitoring of giant panda.

Allometry indicates giant eyes of giant squid are not exceptional.

PubMed

Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Gamarra, Ashlee R; Lee, Johanna J; Wainwright, Peter C

2013-02-18

The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone.

Multiple Giant Coronary Artery Aneurysms

PubMed Central

Marla, Rammohan; Ebel, Rachel; Crosby, Marcus; Almassi, G. Hossein

2009-01-01

Coronary artery aneurysms are rare, and giant coronary artery aneurysms are even rarer. We describe a patient who had giant coronary aneurysms of the right, left circumflex, and left anterior descending coronary arteries. The aneurysms were successfully treated with surgical intervention. To the best of our knowledge, ours is the 1st report of giant aneurysms involving all 3 major coronary arteries. PMID:19568397

78 FR 77362 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-23

... large medium or giant BFT to two large medium or giant BFT for the January 2014 subquota period ((i.e... starting on January 1 would be the default retention limit of one large medium or giant BFT (measuring 73... adjusted the General category limit from the default level of one large medium or giant BFT to two large...

76 FR 76900 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-09

... retention limit of one large medium or giant BFT (measuring 73 inches (185 cm) CFL) or greater per vessel... level of one large medium or giant BFT as follows: Two large medium or giant BFT for January (75 FR 79309, December 20, 2010); three large medium or giant BFT for June through August (76 FR 32086, June 3...

75 FR 79309 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-20

... limit of one large medium or giant BFT (measuring 73 inches (185 cm) CFL) or greater per vessel per day... adjusted the General category limit from the default level of one large medium or giant BFT as follows: Two large medium or giant BFT for January (74 FR 68709, December 29, 2009), and three large medium or giant...

Non-radial oscillation modes with long lifetimes in giant stars.

PubMed

De Ridder, Joris; Barban, Caroline; Baudin, Frédéric; Carrier, Fabien; Hatzes, Artie P; Hekker, Saskia; Kallinger, Thomas; Weiss, Werner W; Baglin, Annie; Auvergne, Michel; Samadi, Réza; Barge, Pierre; Deleuil, Magali

2009-05-21

Towards the end of their lives, stars like the Sun greatly expand to become red giant stars. Such evolved stars could provide stringent tests of stellar theory, as many uncertainties of the internal stellar structure accumulate with age. Important examples are convective overshooting and rotational mixing during the central hydrogen-burning phase, which determine the mass of the helium core, but which are not well understood. In principle, analysis of radial and non-radial stellar oscillations can be used to constrain the mass of the helium core. Although all giants are expected to oscillate, it has hitherto been unclear whether non-radial modes are observable at all in red giants, or whether the oscillation modes have a short or a long mode lifetime, which determines the observational precision of the frequencies. Here we report the presence of radial and non-radial oscillations in more than 300 giant stars. For at least some of the giants, the mode lifetimes are of the order of a month. We observe giant stars with equally spaced frequency peaks in the Fourier spectrum of the time series, as well as giants for which the spectrum seems to be more complex. No satisfactory theoretical explanation currently exists for our observations.

Establishment and cryopreservation of a giant panda skeletal muscle-derived cell line.

PubMed

Yu, Fang-Jian; Zeng, Chang-Jun; Zhang, Yan; Wang, Cheng-Dong; Xiong, Tie-Yi; Fang, Sheng-Guo; Zhang, He-Min

2015-06-01

The giant panda Ailuropoda melanoleuca is an endangered species and is a symbol for wildlife conservation. Although efforts have been made to protect this rare and endangered species through breeding and conservative biology, the long-term preservation of giant panda genome resources (gametes, tissues, organs, genomic libraries, etc.) is still a practical option. In this study, the giant panda skeletal muscle-derived cell line was successfully established via primary explants culture and cryopreservation techniques. The population doubling time of giant panda skeletal cells was approximately 33.8 h, and this population maintained a high cell viability before and after cryopreservation (95.6% and 90.7%, respectively). The two skeletal muscle-specific genes SMYD1 and MYF6 were expressed and detected by RT-PCR in the giant panda skeletal muscle-derived cell line. Karyotyping analysis revealed that the frequencies of giant panda skeletal muscle cells showing a chromosome number of 2n=42 ranged from 90.6∼94.2%. Thus, the giant panda skeletal muscle-derived cell line provides a vital resource and material platform for further studies and is likely to be useful for the protection of this rare and endangered species.

Testing giant planet formation in the transitional disk of SAO 206462 using deep VLT/SPHERE imaging

NASA Astrophysics Data System (ADS)

Maire, A.-L.; Stolker, T.; Messina, S.; Müller, A.; Biller, B. A.; Currie, T.; Dominik, C.; Grady, C. A.; Boccaletti, A.; Bonnefoy, M.; Chauvin, G.; Galicher, R.; Millward, M.; Pohl, A.; Brandner, W.; Henning, T.; Lagrange, A.-M.; Langlois, M.; Meyer, M. R.; Quanz, S. P.; Vigan, A.; Zurlo, A.; van Boekel, R.; Buenzli, E.; Buey, T.; Desidera, S.; Feldt, M.; Fusco, T.; Ginski, C.; Giro, E.; Gratton, R.; Hubin, N.; Lannier, J.; Le Mignant, D.; Mesa, D.; Peretti, S.; Perrot, C.; Ramos, J. R.; Salter, G.; Samland, M.; Sissa, E.; Stadler, E.; Thalmann, C.; Udry, S.; Weber, L.

2017-05-01

Context. The SAO 206462 (HD 135344B) disk is one of the few known transitional disks showing asymmetric features in scattered light and thermal emission. Near-infrared scattered-light images revealed two bright outer spiral arms and an inner cavity depleted in dust. Giant protoplanets have been proposed to account for the disk morphology. Aims: We aim to search for giant planets responsible for the disk features and, in the case of non-detection, to constrain recent planet predictions using the data detection limits. Methods: We obtained new high-contrast and high-resolution total intensity images of the target spanning the Y to the K bands (0.95-2.3 μm) using the VLT/SPHERE near-infrared camera and integral field spectrometer. Results: The spiral arms and the outer cavity edge are revealed at high resolutions and sensitivities without the need for aggressive image post-processing techniques, which introduce photometric biases. We do not detect any close-in companions. For the derivation of the detection limits on putative giant planets embedded in the disk, we show that the knowledge of the disk aspect ratio and viscosity is critical for the estimation of the attenuation of a planet signal by the protoplanetary dust because of the gaps that these putative planets may open. Given assumptions on these parameters, the mass limits can vary from 2-5 to 4-7 Jupiter masses at separations beyond the disk spiral arms. The SPHERE detection limits are more stringent than those derived from archival NaCo/L' data and provide new constraints on a few recent predictions of massive planets (4-15 MJ) based on the spiral density wave theory. The SPHERE and ALMA data do not favor the hypotheses on massive giant planets in the outer disk (beyond 0.6''). There could still be low-mass planets in the outer disk and/or planets inside the cavity. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 095.C-0298 and 090.C-0443.

The association between giant hydrocele and depression in a rural clinic in Nigeria.

PubMed

Dienye, Paul O; Gbeneol, Precious K; Akani, Alexander B

2011-09-01

One of the dreaded disfiguring disease conditions among the Andoni tribesmen in the Nigerian Niger delta region is hydrocele, especially when its size is large (giant hydrocele) and it cannot be concealed. This case-control study was designed to evaluate the prevalence of depression among patients with giant hydrocele presenting to Bethesda Clinic Ngo, Andoni, Nigeria. A total of 52 patients were recruited into this study: 26 in the giant hydrocele group and 26 in the control group. Their age range was 23 to 78 years, with a mean age of 53.4 ± 15.5 years for the giant hydrocele group and 53.6 ± 14.2 years for the control group. The difference between the prevalence of depression among patients that presented with giant hydrocele (61.54%) and the controls (15.38%) was statistically significant (p = .0015). The authors conclude that depression is common among patients with giant hydrocele when compared with patients with other disease conditions.

Cell-sized asymmetric lipid vesicles facilitate the investigation of asymmetric membranes

NASA Astrophysics Data System (ADS)

Kamiya, Koki; Kawano, Ryuji; Osaki, Toshihisa; Akiyoshi, Kazunari; Takeuchi, Shoji

2016-09-01

Asymmetric lipid giant vesicles have been used to model the biochemical reactions in cell membranes. However, methods for producing asymmetric giant vesicles lead to the inclusion of an organic solvent layer that affects the mechanical and physical characteristics of the membrane. Here we describe the formation of asymmetric giant vesicles that include little organic solvent, and use them to investigate the dynamic responses of lipid molecules in the vesicle membrane. We formed the giant vesicles via the inhomogeneous break-up of a lipid microtube generated by applying a jet flow to an asymmetric planar lipid bilayer. The asymmetric giant vesicles showed a lipid flip-flop behaviour in the membrane, superficially similar to the lipid flip-flop activity observed in apoptotic cells. In vitro synthesis of membrane proteins into the asymmetric giant vesicles revealed that the lipid asymmetry in bilayer membranes improves the reconstitution ratio of membrane proteins. Our asymmetric giant vesicles will be useful in elucidating lipid-lipid and lipid-membrane protein interactions involved in the regulation of cellular functions.

SOCS3: an essential regulator of LIF receptor signaling in trophoblast giant cell differentiation

PubMed Central

Takahashi, Yutaka; Carpino, Nick; Cross, James C.; Torres, Miguel; Parganas, Evan; Ihle, James N.

2003-01-01

Suppressor of cytokine signaling 3 (SOCS3) binds cytokine receptors and thereby suppresses cytokine signaling. Deletion of SOCS3 causes an embryonic lethality that is rescued by a tetraploid rescue approach, demonstrating an essential role in placental development and a non-essential role in embryo development. Rescued SOCS3-deficient mice show a perinatal lethality with cardiac hypertrophy. SOCS3-deficient placentas have reduced spongiotrophoblasts and increased trophoblast secondary giant cells. Enforced expression of SOCS3 in a trophoblast stem cell line (Rcho-1) suppresses giant cell differentiation. Conversely, SOCS3-deficient trophoblast stem cells differentiate more readily to giant cells in culture, demonstrating that SOCS3 negatively regulates trophoblast giant cell differentiation. Leukemia inhibitory factor (LIF) promotes giant cell differentiation in vitro, and LIF receptor (LIFR) deficiency results in loss of giant cell differentiation in vivo. Finally, LIFR deficiency rescues the SOCS3-deficient placental defect and embryonic lethality. The results establish SOCS3 as an essential regulator of LIFR signaling in trophoblast differentiation. PMID:12554639

An evaluation of the efficacy of using environmental DNA (eDNA) to detect giant gartersnakes (Thamnophis gigas)

USGS Publications Warehouse

Halstead, Brian J.; Wood, Dustin A.; Bowen, Lizabeth; Waters, Shannon C.; Vandergast, Amy G.; Ersan, Julia S.; Skalos, Shannon M.; Casazza, Michael L.

2017-09-28

Detecting populations of rare or cryptic species is essential for their conservation. For species like giant gartersnakes (Thamnophis gigas), conventional survey methods can be expensive and inefficient. These sampling difficulties might be overcome by modern techniques that detect deoxyribonucleic acid (DNA) shed by organisms into the environment (eDNA). We evaluated the efficacy of detecting giant gartersnake eDNA in water samples from the laboratory and at locations with known giant gartersnake populations in the Sacramento Valley of California, and failed to detect giant gartersnake DNA in most laboratory and all field samples. Aspects of giant gartersnake biology—such as highly keratinized skin and spending extensive time in the terrestrial environment, as well as hot, sunny, and turbid conditions in wetlands and canals of the Sacramento Valley—likely contributed to low detection probabilities. Although detection of eDNA shows promise under many conditions, further development is needed before sampling for eDNA is a viable option for detecting giant gartersnake populations.

Giant Magellan Telescope

Science.gov Websites

collaborate with the National Optical Astronomy Observatory (NOAO) and the Thirty Meter Telescope (TMT) to articulate a community based science program for presentation to the next Decadal Survey of Astronomy and

An empirical mass-loss law for Population II giants from the Spitzer-IRAC survey of Galactic globular clusters

NASA Astrophysics Data System (ADS)

Origlia, L.; Ferraro, F. R.; Fabbri, S.; Fusi Pecci, F.; Dalessandro, E.; Rich, R. M.; Valenti, E.

2014-04-01

Aims: The main aim of the present work is to derive an empirical mass-loss (ML) law for Population II stars in first and second ascent red giant branches. Methods: We used the Spitzer InfraRed Array Camera (IRAC) photometry obtained in the 3.6-8 μm range of a carefully chosen sample of 15 Galactic globular clusters spanning the entire metallicity range and sampling the vast zoology of horizontal branch (HB) morphologies. We complemented the IRAC photometry with near-infrared data to build suitable color-magnitude and color-color diagrams and identify mass-losing giant stars. Results: We find that while the majority of stars show colors typical of cool giants, some stars show an excess of mid-infrared light that is larger than expected from their photospheric emission and that is plausibly due to dust formation in mass flowing from them. For these stars, we estimate dust and total (gas + dust) ML rates and timescales. We finally calibrate an empirical ML law for Population II red and asymptotic giant branch stars with varying metallicity. We find that at a given red giant branch luminosity only a fraction of the stars are losing mass. From this, we conclude that ML is episodic and is active only a fraction of the time, which we define as the duty cycle. The fraction of mass-losing stars increases by increasing the stellar luminosity and metallicity. The ML rate, as estimated from reasonable assumptions for the gas-to-dust ratio and expansion velocity, depends on metallicity and slowly increases with decreasing metallicity. In contrast, the duty cycle increases with increasing metallicity, with the net result that total ML increases moderately with increasing metallicity, about 0.1 M⊙ every dex in [Fe/H]. For Population II asymptotic giant branch stars, we estimate a total ML of ≤0.1 M⊙, nearly constant with varying metallicity. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.Appendix A is available in electronic form at http://www.aanda.org

An Investigation of Cellulose Digesting Bacteria in the Panda Gut Microbiome

NASA Astrophysics Data System (ADS)

Lu, M.; Leung, F. C.

2014-12-01

The Giant Panda (Ailuropoda melanoleuca) diet consists primarily of bamboo leaves, stems and shoots. However, the Giant Panda lacks genes for the enzymes needed to digest cellulose, the core component of bamboo. Thus, it is hypothesized that the cellulolytic digestion necessary for maintaining the Giant Panda diet is carried out by microbial symbionts in the panda gut microbiota. Fecal microbiota is used as surrogate index for gut microbiota since the Giant Panda is listed by the World Conservation Union as a Threatened Species. Two bacterial isolates with potential cellulolytic activity were isolated from Giant Panda fecal samples and cultured on selective media CMC (carboxymethyl cellulose) agar and CMC-Congo Red agar using various methods of inoculation. After incubation, clearance zones around colonies were observed and used as qualitative assays for cellulose digestion. Polymerase chain reaction amplification of the 16S rRNA gene was completed and species identification was done based on the BLAST result of 16S rRNA sequence obtained using Sanger sequencing. Once the cellulase activity is confirmed, genomic DNA of the bacteria will be extracted and used for whole genome shotgun sequencing. Illumina next generation sequencing platform will be adopted as it yields high-throughput information, providing a better understanding of cellulose digestion and the molecular genetic pathways to renewable sources of biofuels. Researchers have identified multiple cellulose-digesting microbes in the Giant Panda gut, but few have applied such bacteria in converting cellulose into glucose to create biofuel. Cellulosic ethanol, a biofuel, is produced through the fermentation of lignocellulosic biomasses. This anaerobic process is aided by cellulose-digesting enzymes. Certain microbes, such as those present in the Giant Panda gut, can produce enzymes that cleave the glycosidic bonds of cellulose (C6H10O5) into glucose molecules (C6H12O6), which can then be fermented into ethanol in the presence of yeast (C6H12O6 → 2C2H5OH + 2CO2), producing cellulosic biofuel. Our aim is to identify cellulose-digesting microbes and test their ability to produce biofuels efficiently. The Renewable Fuels Association estimates that ethanol fuel can reduce CO2 emissions by up to 44% and reduce CO tailpipe emissions by up to 30%.

Abundances of disk and bulge giants from high-resolution optical spectra. I. O, Mg, Ca, and Ti in the solar neighborhood and Kepler field samples

NASA Astrophysics Data System (ADS)

Jönsson, H.; Ryde, N.; Nordlander, T.; Pehlivan Rhodin, A.; Hartman, H.; Jönsson, P.; Eriksson, K.

2017-02-01

Context. The Galactic bulge is an intriguing and significant part of our Galaxy, but it is hard to observe because it is both distant and covered by dust in the disk. Therefore, there are not many high-resolution optical spectra of bulge stars with large wavelength coverage, whose determined abundances can be compared with nearby, similarly analyzed stellar samples. Aims: We aim to determine the diagnostically important alpha elements of a sample of bulge giants using high-resolution optical spectra with large wavelength coverage. The abundances found are compared to similarly derived abundances from similar spectra of similar stars in the local thin and thick disks. In this first paper we focus on the solar neighborhood reference sample. Methods: We used spectral synthesis to derive the stellar parameters as well as the elemental abundances of both the local and bulge samples of giants. We took special care to benchmark our method of determining stellar parameters against independent measurements of effective temperatures from angular diameter measurements and surface gravities from asteroseismology. Results: In this first paper we present the method used to determine the stellar parameters and elemental abundances, evaluate them, and present the results for our local disk sample of 291 giants. Conclusions: When comparing our determined spectroscopic temperatures to those derived from angular diameter measurements, we reproduce these with a systematic difference of +10 K and a standard deviation of 53 K. The spectroscopic gravities reproduce those determined from asteroseismology with a systematic offset of +0.10 dex and a standard deviation of 0.12 dex. When it comes to the abundance trends, our sample of local disk giants closely follows trends found in other works analyzing solar neighborhood dwarfs, showing that the much brighter giant stars are as good abundance probes as the often used dwarfs. Based on observations made with the Nordic Optical Telescope (programs 51-018 and 53-002), operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias, and on spectral data retrieved from PolarBase at Observatoire Midi Pyrénées.Full Tables A.1 and A.3 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A100

AN EXTRAORDINARY OUTBURST OF THE MAGNETAR SWIFT J1822.3–1606

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

Chakraborty, Manoneeta; Göğüş, Ersin

2015-08-20

The 2011 outburst of Swift J1822.3–1606 was extraordinary; periodic modulations at the spin period of the underlying neutron star were clearly visible, remarkably similar to what is observed during the decaying tail of magnetar giant flares. We investigated the temporal characteristics of X-ray emission during the early phases of the outburst. We performed a periodicity search with the spectral hardness ratio (HR) and found a coherent signal near the spin period of the neutron star, but with a lag of about 3 radians. Therefore, the HR is strongly anti-correlated with the X-ray intensity, which is also seen in the giantmore » flares. We studied the time evolution of the pulse profile and found that it evolves from a complex morphology to a much simpler shape within about a month. Pulse profile simplification also takes place during the giant flares, but on a much shorter timescale of about a few minutes. We found that the amount of energy emitted during the first 25 days of the outburst is comparable to what was detected in minutes during the decaying tail of giant flares. Based on these similarities, we suggest that the triggering mechanisms of the giant flares and the magnetar outbursts are likely the same. We propose that the trapped fireball that develops in the magnetosphere at the onset of the outburst radiates away efficiently in minutes in magnetars exhibiting giant flares, while in other magnetars, such as Swift J1822.3–1606, the efficiency of radiation of the fireball is not as high and, therefore, lasts much longer.« less

X-Ray and Optical Observations of A 0535+26

NASA Technical Reports Server (NTRS)

Camero-Arranz, A.; Finger, M. H.; Wilson-Hodge, C. A.; Jenke, P.; Steele, I.; Coe, M. J.; Gutierrez-Soto, J.; Kretschmar, P.; Caballero, I.; Yan, J.;

Detection of planet candidates around K giants. HD 40956, HD 111591, and HD 113996

NASA Astrophysics Data System (ADS)

Jeong, G.; Lee, B.-C.; Han, I.; Omiya, M.; Izumiura, H.; Sato, B.; Harakawa, H.; Kambe, E.; Mkrtichian, D.

2018-02-01

Aims: The purpose of this paper is to detect and investigate the nature of long-term radial velocity (RV) variations of K-type giants and to confirm planetary companions around the stars. Methods: We have conducted two planet search programs by precise RV measurement using the 1.8 m telescope at Bohyunsan Optical Astronomy Observatory (BOAO) and the 1.88 m telescope at Okayama Astrophysical Observatory (OAO). The BOAO program searches for planets around 55 early K giants. The OAO program is looking for 190 G-K type giants. Results: In this paper, we report the detection of long-period RV variations of three K giant stars, HD 40956, HD 111591, and HD 113996. We investigated the cause of the observed RV variations and conclude the substellar companions are most likely the cause of the RV variations. The orbital analyses yield P = 578.6 ± 3.3 d, m sin i = 2.7 ± 0.6 MJ, a = 1.4 ± 0.1 AU for HD 40956; P = 1056.4 ± 14.3 d, m sin i = 4.4 ± 0.4 MJ, a = 2.5 ± 0.1 AU for HD 111591; P = 610.2 ± 3.8 d, m sin i = 6.3 ± 1.0 MJ, a = 1.6 ± 0.1 AU for HD 113996. Based on observations made with the BOES at BOAO in Korea and HIDES at OAO in Japan.Tables 3-5 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A3

New Teff and [Fe/H] spectroscopic calibration for FGK dwarfs and GK giants

NASA Astrophysics Data System (ADS)

Teixeira, G. D. C.; Sousa, S. G.; Tsantaki, M.; Monteiro, M. J. P. F. G.; Santos, N. C.; Israelian, G.

2016-10-01

Context. The ever-growing number of large spectroscopic survey programs has increased the importance of fast and reliable methods with which to determine precise stellar parameters. Some of these methods are highly dependent on correct spectroscopic calibrations. Aims: The goal of this work is to obtain a new spectroscopic calibration for a fast estimate of Teff and [Fe/H] for a wide range of stellar spectral types. Methods: We used spectra from a joint sample of 708 stars, compiled from 451 FGK dwarfs and 257 GK-giant stars. We used homogeneously determined spectroscopic stellar parameters to derive temperature calibrations using a set of selected EW line-ratios, and [Fe/H] calibrations using a set of selected Fe I lines. Results: We have derived 322 EW line-ratios and 100 Fe I lines that can be used to compute Teff and [Fe/H], respectively. We show that these calibrations are effective for FGK dwarfs and GK-giant stars in the following ranges: 4500 K

First report of Enterocytozoon bieneusi from giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens) in China.

PubMed

Tian, Ge-Ru; Zhao, Guang-Hui; Du, Shuai-Zhi; Hu, Xiong-Feng; Wang, Hui-Bao; Zhang, Long-Xian; Yu, San-Ke

2015-08-01

Enterocytozoon bieneusi is an emerging and opportunistic enteric pathogen triggering diarrhea and enteric disease in humans and animals. Despite extensive research on this pathogen, the prevalence and genotypes of E. bieneusi infection in precious wild animals of giant and red pandas have not been reported. In the present study, 82 faecal specimens were collected from 46 giant pandas (Ailuropoda melanoleuca) and 36 red pandas (Ailurus fulgens) in the northwest of China. By PCR and sequencing of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene of E. bieneusi, an overall infection rate of 10.98% (9/82) was observed in pandas, with 8.70% (4/46) for giant pandas, and 13.89% (5/36) for red pandas. Two ITS genotypes were identified: the novel genotype I-like (n=4) and genotype EbpC (n=5). Multilocus sequence typing (MLST) employing three microsatellites (MS1, MS3 and MS7) and one minisatellite (MS4) showed that nine, six, six and nine positive products were amplified and sequenced successfully at four respective loci. A phylogenetic analysis based on a neighbor-joining tree of the ITS gene sequences of E. bieneusi indicated that the genotype EbpC fell into 1d of group 1 of zoonotic potential, and the novel genotype I-like was clustered into group 2. The present study firstly indicated the presence of E. bieneusi in giant and red pandas, and these results suggested that integrated strategies should be implemented to effectively protect pandas and humans from infecting E. bieneusi in China. Copyright © 2015 Elsevier B.V. All rights reserved.

The tip of the red giant branch as a distance indicator for resolved galaxies. 2: Computer simulations

NASA Technical Reports Server (NTRS)

Madore, Barry F.; Freedman, Wendy L.

1995-01-01

Based on both empirical data for the nearby galaxies, and on computer simulations, we show that measuring the position of the tip of the first-ascent red-giant branch provides a means of obtaining the distances to nearby galaxies with a precision and accuracy comparable to using Cepheids and/or RR Lyrae variables. We present an analysis of synthetic I vs (V-I) color magnitude diagrams of Population 2 systems to investigate the use of the observed discontinuity in the I-band luminosity function as a primary distance indicator. In the simulations we quantify the effects (1) signal to noise, (2) crowding, (3) population size, and (4) non-giant-branch-star contamination, on the method adopted for detecting the discontinuity,, measuring its luminosity, and estimating its uncertainity. We discuss sources of systematic error in the context of observable parameters, such as the signal-to-noise ratio and/or surface brightness. The simulations are then scaled to observed color-magnitude diagrams. It is concluded, that from the ground the tip of the red-giant-branch method can be sucessfully used to determine distances accurate to +/- 10% for galaxies out to 3 Mpc (mu approximately 27.5 mag); and from space a factor of four further in distance (mu approximately 30.6 mag) can be reached using HST. This method can be applied whereever a metal-poor population (-2.0 less than Z less than -0.7) of red-giant stars is detected (whose age is in the range 7-17 Gyr), whether that population resides in the halo of a spiral galaxy, the extended outer disk of a dwarf irregular, or in the outer periphery of an elliptical galaxy.

Visible and Near-IR Imaging of Giant Planets: Outer Manifestations of Deeper Secrets

NASA Astrophysics Data System (ADS)

Hammel, Heidi B.

1996-09-01

Visible and near-infrared imaging of the giant planets -- Jupiter, Saturn, Uranus, and Neptune -- probes the outermost layers of clouds in these gaseous atmospheres. Not only are the images beautiful and striking in their color and diversity of detail, they also provide quantitative clues to the dynamical and chemical processes taking place both at the cloud tops and deeper in the interior: zonal wind profiles can be extracted; wavelength-dependent center-to-limb brightness variations yield valuable data for modeling vertical aerosol structure; the presence of planetary-scale atmospheric waves can sometimes be deduced; variations of cloud color and brightness with latitude provide insight into the underlying mechanisms driving circulation; development and evolution of discrete atmospheric features trace both exogenic and endogenic events. During the 1980's, our understanding of the giant planets was revolutionized by detailed visible-wavelength images taken by the Voyager spacecraft of these planets' atmospheres. However, those images were static: brief snapshots in time of four complex and dynamic atmospheric systems. In short, those images no longer represent the current appearance of these planets. Recently, our knowledge of the atmospheres of the gas giant planets has undergone major new advances, due in part to the excellent imaging capability and longer-term temporal sampling of the Hubble Space Telescope (HST) and the Galileo Mission to Jupiter. In this talk, I provide an update on our current understanding of the gas giants based on recent visible and near-infrared imaging, highlighting results from the collision of Comet Shoemaker-Levy 9 with Jupiter, Saturn's White Spots, intriguing changes in the atmosphere of Uranus, and Neptune's peripatetic clouds.

Two K Giants with Supermeteoritic Lithium Abundances: HDE 233517 and HD 9746

NASA Astrophysics Data System (ADS)

Balachandran, Suchitra C.; Fekel, Francis C.; Henry, Gregory W.; Uitenbroek, Han

2000-10-01

Two unusual Li-rich K giants, HDE 233517 and HD 9746, have been studied. Optical spectroscopy and photometry have been obtained to determine the fundamental parameters of HDE 233517, a single K2 III with an extremely large infrared excess. The spectra yield Teff=4475 K, logg=2.25, [Fe/H]=-0.37, vsini=17.6 km s-1, and a non-LTE logɛ(7Li)=4.22. Photometric observations reveal low-amplitude light variability with a period of 47.9 days. Combined with other parameters, this results in a minimum radius of 16.7 Rsolar and minimum distance of 617 pc. Comparison of spectra obtained in 1994 and 1996 show profile variations in Hα and the Na D lines indicative of changing mass loss. Optical spectra of HD 9746, a chromospherically active giant, were analyzed. The Teff=4400 K and revised Hipparcos-based gravity of logg=2.30 lead to a non-LTE logɛ(7Li)=3.75. The Li abundances in both stars are supermeteoritic. By the inclusion and exclusion of 6Li in the syntheses, we show that consistent 7Li abundances are obtained only when 6Li is absent in the synthetic fit. This provides evidence for fresh 7Li production and excludes both preservation of primordial Li and planetary accretion as viable scenarios for the formation of Li-rich giants. Both stars lie in close proximity to the red giant luminosity bump supporting the hypothesis that 7Li production is caused by the same mixing mechanism that later results in CN processing and lowers the 12C/13C ratio to nonstandard values.

Mitochondrial DNA sequence evolution in the Arctoidea.

PubMed

Zhang, Y P; Ryder, O A

1993-10-15

Some taxa in the superfamily Arctoidea, such as the giant panda and the lesser panda, have presented puzzles to taxonomists. In the present study, approximately 397 bases of the cytochrome b gene, 364 bases of the 12S rRNA gene, and 74 bases of the tRNA(Thr) and tRNA(Pro) genes from the giant panda, lesser panda, kinkajou, raccoon, coatimundi, and all species of the Ursidae were sequenced. The high transition/transversion ratios in cytochrome b and RNA genes prior to saturation suggest that the presumed transition bias may represent a trend for some mammalian lineages rather than strictly a primate phenomenon. Transversions in the 12S rRNA gene accumulate in arctoids at about half the rate reported for artiodactyls. Different arctoid lineages evolve at different rates: the kinkajou, a procyonid, evolves the fastest, 1.7-1.9 times faster than the slowest lineage that comprises the spectacled and polar bears. Generation-time effect can only partially explain the different rates of nucleotide substitution in arctoids. Our results based on parsimony analysis show that the giant panda is more closely related to bears than to the lesser panda; the lesser panda is neither closely related to bears nor to the New World procyonids. The kinkajou, raccoon, and coatimundi diverged from each other very early, even though they group together. The polar bear is closely related to the spectacled bear, and they began to diverge from a common mitochondrial ancestor approximately 2 million years ago. Relationships of the remaining five bear species are derived.

Mitochondrial DNA sequence evolution in the Arctoidea.

PubMed Central

Zhang, Y P; Ryder, O A

1993-01-01

Some taxa in the superfamily Arctoidea, such as the giant panda and the lesser panda, have presented puzzles to taxonomists. In the present study, approximately 397 bases of the cytochrome b gene, 364 bases of the 12S rRNA gene, and 74 bases of the tRNA(Thr) and tRNA(Pro) genes from the giant panda, lesser panda, kinkajou, raccoon, coatimundi, and all species of the Ursidae were sequenced. The high transition/transversion ratios in cytochrome b and RNA genes prior to saturation suggest that the presumed transition bias may represent a trend for some mammalian lineages rather than strictly a primate phenomenon. Transversions in the 12S rRNA gene accumulate in arctoids at about half the rate reported for artiodactyls. Different arctoid lineages evolve at different rates: the kinkajou, a procyonid, evolves the fastest, 1.7-1.9 times faster than the slowest lineage that comprises the spectacled and polar bears. Generation-time effect can only partially explain the different rates of nucleotide substitution in arctoids. Our results based on parsimony analysis show that the giant panda is more closely related to bears than to the lesser panda; the lesser panda is neither closely related to bears nor to the New World procyonids. The kinkajou, raccoon, and coatimundi diverged from each other very early, even though they group together. The polar bear is closely related to the spectacled bear, and they began to diverge from a common mitochondrial ancestor approximately 2 million years ago. Relationships of the remaining five bear species are derived. PMID:8415740

Development and impact of biological control of giant reed, Arundo donax, in the Rio Grande Basin of the U.S. and Mexico

USDA-ARS?s Scientific Manuscript database

Giant reed (Arundo donax L.) also known as giant cane or carrizo cane, is an exotic perennial grass that has infested over 60,000 hectares along riparian corridors in the southwestern U.S. The most severe infestations are in the Lower Rio Grande Basin, where giant reed along the Rio Grande and Mexic...

Giant cell arteritis mimicking a testicular tumour.

PubMed

Sundaram, S; Smith, D H

2001-07-01

Giant cell arteritis involving the testis was identified incidentally upon orchidectomy of a right testicular mass. The mass looked like a malignant process on ultrasound. The patient also had generalised disease and was treated appropriately. Giant cell arteritis involving the bladder, prostate, uterus, and adnexa have been described before. To our knowledge, this is the first described case of giant cell arteritis affecting the testis.

Unusual Giant Prostatic Urethral Calculus

PubMed Central

Bello, A.; Maitama, H. Y.; Mbibu, N. H.; Kalayi, G. D.; Ahmed, A.

2010-01-01

Giant vesico-prostatic urethral calculus is uncommon. Urethral stones rarely form primarily in the urethra, and they are usually associated with urethral strictures, posterior urethral valve or diverticula. We report a case of a 32-year-old man with giant vesico-prostatic (collar-stud) urethral stone presenting with sepsis and bladder outlet obstruction. The clinical presentation, management, and outcome of the giant prostatic urethral calculus are reviewed. PMID:22091328

Dynamical Upheaval in Ice Giant Formation: A Solution to the Fine-tuning Problem in the Formation Story

NASA Astrophysics Data System (ADS)

Frelikh, Renata; Murray-Clay, Ruth

2018-04-01

We report on our recent theoretical work, where we suggest that a protoplanetary disk dynamical instability may have played a crucial role in determining the atmospheric size of the solar system’s ice giants. In contrast to the gas giants, the intermediate-size ice giants never underwent runaway gas accretion in a full gas disk. However, as their substantial core masses are comparable to those of the gas giants, they would have gone runaway, given enough time. In the standard scenario, the ice giants stay at roughly their current size for most of the disk lifetime, undergoing period of slow gas accretion onto ~full-sized cores that formed early-on. The gas disk dissipates before the ice giants accumulate too much gas, but we believe this is fine tuned. A considerable amount of solids is observed in outer disks in mm-to-cm sized particles (pebbles). Assisted by gas drag, these pebbles rapidly accrete onto cores. This would cause the growing ice giants to exceed their current core masses, and quickly turn into gas giants. To resolve this problem, we propose that Uranus and Neptune stayed small for the bulk of the disk lifetime. They only finished their core and atmospheric growth in a short timeframe just as the disk gas dissipated, accreting most of their gas from a disk depleted to ~1% of its original mass. The ice giants have atmospheric mass fractions comparable to the disk gas-to-solid ratio of this depleted disk. This coincides with a disk dynamical upheaval onset by the depletion of gas. We propose that the cores started growing closer-in, where they were kept small by proximity to Jupiter and Saturn. As the gas cleared, the cores were kicked out by the gas giants. Then, they finished their core growth and accreted their atmospheres from the remaining, sparse gas at their current locations. We predict that the gas giants may play a key role in forming intermediate-size atmospheres in the outer disk.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

NASA Launch Director Charlie Blackwell-Thompson, center, talks to engineers at Launch Pad 39B at the agency's Kennedy Space Center in Florida. Blackwell-Thompson will observe the first major tanking operation of liquid oxygen, or LO2, into the giant storage sphere at the northwest corner of the pad to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. During the operation, several Praxair trucks will slowly offload LO2 to gradually chill down the sphere from normal temperature to about negative 298 degrees Fahrenheit. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

NASA Launch Director Charlie Blackwell-Thompson, at right, greets engineers and technicians at Launch Pad 39B at the agency's Kennedy Space Center in Florida. Blackwell-Thompson will observe the first major tanking operation of liquid oxygen, or LO2, into the giant storage sphere at the northwest corner of the pad to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. During the operation, several Praxair trucks will slowly offload LO2 to gradually chill down the sphere from normal temperature to about negative 298 degrees Fahrenheit. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Several Praxair trucks carrying their loads of liquid oxygen, or LO2, have arrived at Launch Pad 39B at NASA's Kennedy Space Center in Florida. A mist is visible as LO2 is offloaded from one of the trucks into the giant storage sphere located at the northwest corner of the pad has begun. The sphere will gradually be chilled down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Several Praxair trucks carrying their loads of liquid oxygen, or LO2, have arrived at Launch Pad 39B at NASA's Kennedy Space Center in Florida. The trucks will begin to offload the LO2 one at a time into the giant storage sphere located at the northwest corner of the pad. The sphere will gradually be chilled down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

Cryo Tank Fill at Pad 39B

NASA Image and Video Library

2017-09-26

Engineers watch as several Praxair trucks carrying their loads of liquid oxygen, or LO2, arrive at Launch Pad 39B at NASA's Kennedy Space Center in Florida. The trucks will offload the LO2 one at a time into the giant storage sphere located at the northwest corner of the pad. The sphere will gradually be chilled down from normal temperature to about negative 298 degrees Fahrenheit, during the first major integrated operation to prepare for the launch of the agency's Orion spacecraft atop the Space Launch System (SLS) rocket. The Ground Systems Development and Operations Program is overseeing upgrades and modifications to pad B to support the launch of the SLS and Orion spacecraft for Exploration Mission-1, deep space missions and NASA’s journey to Mars.

A rare cause of dysphagia: compression of the esophagus by an anterior cervical osteophyte due to ankylosing spondylitis.

PubMed

Albayrak, Ilknur; Bağcacı, Sinan; Sallı, Ali; Kucuksen, Sami; Uğurlu, Hatice

2013-09-01

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatological disease affecting the axial skeleton with various extra-articular complications. Dysphagia due to a giant anterior osteophyte of the cervical spine in AS is extremely rare. We present a 48-year-old male with AS suffering from progressive dysphagia to soft foods and liquids. Esophagography showed an anterior osteophyte at C5-C6 resulting in esophageal compression. The patient refused surgical resection of the osteophyte and received conservative therapy. However, after 6 months there was no improvement in dysphagia. This case illustrates that a large cervical osteophyte may be the cause of dysphagia in patients with AS and should be included in the diagnostic workup in early stages of the disease.

METAL-POOR LITHIUM-RICH GIANTS IN THE RADIAL VELOCITY EXPERIMENT SURVEY

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

Ruchti, Gregory R.; Fulbright, Jon P.; Wyse, Rosemary F. G.

We report the discovery of eight lithium-rich field giants found in a high-resolution spectroscopic sample of over 700 metal-poor stars ([Fe/H] < -0.5) selected from the Radial Velocity Experiment survey. The majority of the Li-rich giants in our sample are very metal-poor ([Fe/H] {approx}< -1.9), and have a Li abundance (in the form of {sup 7}Li), A(Li) = log (n(Li)/n(H)) + 12, between 2.30 and 3.63, well above the typical upper red giant branch (RGB) limit, A(Li) < 0.5, while two stars, with A(Li) {approx} 1.7-1.8, show similar lithium abundances to normal giants at the same gravity. We further includedmore » two metal-poor, Li-rich globular cluster giants in our sample, namely the previously discovered M3-IV101 and newly discovered (in this work) M68-A96. This comprises the largest sample of metal-poor Li-rich giants to date. We performed a detailed abundance analysis of all stars, finding that the majority of our sample stars have elemental abundances similar to that of Li-normal halo giants. Although the evolutionary phase of each Li-rich giant cannot be definitively determined, the Li-rich phase is likely connected to extra mixing at the RGB bump or early asymptotic giant branch that triggers cool bottom processing in which the bottom of the outer convective envelope is connected to the H-burning shell in the star. The surface of a star becomes Li-enhanced as {sup 7}Be (which burns to {sup 7}Li) is transported to the stellar surface via the Cameron-Fowler mechanism. We discuss and discriminate among several models for the extra mixing that can cause Li production, given the detailed abundances of the Li-rich giants in our sample.« less

Impacts of temperature on giant panda habitat in the north Minshan Mountains.

PubMed

Liu, Gang; Guan, Tianpei; Dai, Qiang; Li, Huixin; Gong, Minghao

2016-02-01

Understanding the impacts of meteorological factors on giant pandas is necessary for future conservation measures in response to global climate change. We integrated temperature data with three main habitat parameters (elevation, vegetation type, and bamboo species) to evaluate the influence of climate change on giant panda habitat in the northern Minshan Mountains using a habitat assessment model. Our study shows that temperature (relative importance = 25.1%) was the second most important variable influencing giant panda habitat excepting the elevation. There was a significant negative correlation between temperature and panda presence (ρ = -0.133, P < 0.05), and the temperature range preferred by giant pandas within the study area was 18-21°C, followed by 15-17°C and 22-24°C. The overall suitability of giant panda habitats will increase by 2.7%, however, it showed a opposite variation patterns between the eastern and northwestern region of the study area. Suitable and subsuitable habitats in the northwestern region of the study area, which is characterized by higher elevation and latitude, will increase by 18007.8 hm(2) (9.8% habitat suitability), while the eastern region will suffer a decrease of 9543.5 hm(2) (7.1% habitat suitability). Our results suggest that increasing areas of suitable giant panda habitat will support future giant panda expansion, and food shortage and insufficient living space will not arise as problems in the northwest Minshan Mountains, which means that giant pandas can adapt to climate change, and therefore may be resilient to climate change. Thus, for the safety and survival of giant pandas in the Baishuijiang Reserve, we propose strengthening the giant panda monitoring program in the west and improving the integrity of habitats to promote population dispersal with adjacent populations in the east.

Formation of terrestrial planets in eccentric and inclined giant planet systems

NASA Astrophysics Data System (ADS)

Sotiriadis, Sotiris; Libert, Anne-Sophie; Raymond, Sean N.

2018-06-01

Aims: Evidence of mutually inclined planetary orbits has been reported for giant planets in recent years. Here we aim to study the impact of eccentric and inclined massive giant planets on the terrestrial planet formation process, and investigate whether it can possibly lead to the formation of inclined terrestrial planets. Methods: We performed 126 simulations of the late-stage planetary accretion in eccentric and inclined giant planet systems. The physical and orbital parameters of the giant planet systems result from n-body simulations of three giant planets in the late stage of the gas disc, under the combined action of Type II migration and planet-planet scattering. Fourteen two- and three-planet configurations were selected, with diversified masses, semi-major axes (resonant configurations or not), eccentricities, and inclinations (including coplanar systems) at the dispersal of the gas disc. We then followed the gravitational interactions of these systems with an inner disc of planetesimals and embryos (nine runs per system), studying in detail the final configurations of the formed terrestrial planets. Results: In addition to the well-known secular and resonant interactions between the giant planets and the outer part of the disc, giant planets on inclined orbits also strongly excite the planetesimals and embryos in the inner part of the disc through the combined action of nodal resonance and the Lidov-Kozai mechanism. This has deep consequences on the formation of terrestrial planets. While coplanar giant systems harbour several terrestrial planets, generally as massive as the Earth and mainly on low-eccentric and low-inclined orbits, terrestrial planets formed in systems with mutually inclined giant planets are usually fewer, less massive (<0.5 M⊕), and with higher eccentricities and inclinations. This work shows that terrestrial planets can form on stable inclined orbits through the classical accretion theory, even in coplanar giant planet systems emerging from the disc phase.

Fast Ignition and Sustained Combustion of Ionic Liquids

NASA Technical Reports Server (NTRS)

Joshi, Prakash B. (Inventor); Piper, Lawrence G. (Inventor); Oakes, David B. (Inventor); Sabourin, Justin L. (Inventor); Hicks, Adam J. (Inventor); Green, B. David (Inventor); Tsinberg, Anait (Inventor); Dokhan, Allan (Inventor)

2016-01-01

A catalyst free method of igniting an ionic liquid is provided. The method can include mixing a liquid hypergol with a HAN (Hydroxylammonium nitrate)-based ionic liquid to ignite the HAN-based ionic liquid in the absence of a catalyst. The HAN-based ionic liquid and the liquid hypergol can be injected into a combustion chamber. The HAN-based ionic liquid and the liquid hypergol can impinge upon a stagnation plate positioned at top portion of the combustion chamber.

Giant Cell Arteritis

MedlinePlus

Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

Equations of state for hydrogen and deuterium.

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

Kerley, Gerald Irwin

2003-12-01

This report describes the complete revision of a deuterium equation of state (EOS) model published in 1972. It uses the same general approach as the 1972 EOS, i.e., the so-called 'chemical model,' but incorporates a number of theoretical advances that have taken place during the past thirty years. Three phases are included: a molecular solid, an atomic solid, and a fluid phase consisting of both molecular and atomic species. Ionization and the insulator-metal transition are also included. The most important improvements are in the liquid perturbation theory, the treatment of molecular vibrations and rotations, and the ionization equilibrium and mixturemore » models. In addition, new experimental data and theoretical calculations are used to calibrate certain model parameters, notably the zero-Kelvin isotherms for the molecular and atomic solids, and the quantum corrections to the liquid phase. The report gives a general overview of the model, followed by detailed discussions of the most important theoretical issues and extensive comparisons with the many experimental data that have been obtained during the last thirty years. Questions about the validity of the chemical model are also considered. Implications for modeling the 'giant planets' are also discussed.« less

Space Shuttle Projects

NASA Image and Video Library

1976-01-01

This is a cutaway illustration of the Space Shuttle external tank (ET) with callouts. The giant cylinder, higher than a 15-story building, with a length of 154-feet (47-meters) and a diameter of 27.5-feet (8.4-meters), is the largest single piece of the Space Shuttle. During launch, the ET also acts as a backbone for the orbiter and solid rocket boosters. Separate pressurized tank sections within the external tank hold the liquid hydrogen fuel and liquid oxygen oxidizer for the Shuttle's three main engines. During launch, the ET feeds the fuel under pressure through 17-inch (43.2-centimeter) ducts that branch off into smaller lines that feed directly into the main engines. The main engines consume 64,000 gallons (242,260 liters) of fuel each minute. Machined from aluminum alloys, the Space Shuttle's external tank is currently the only part of the launch vehicle that is not reused. After its 526,000-gallons (1,991,071 liters) of propellants are consumed during the first 8.5-minutes of flight, it is jettisoned from the orbiter and breaks up in the upper atmosphere, its pieces falling into remote ocean waters. The Marshall Space Flight Center was responsible for developing the ET.

Expression of CD 68, CD 45 and human leukocyte antigen-DR in central and peripheral giant cell granuloma, giant cell tumor of long bones, and tuberculous granuloma: An immunohistochemical study.

PubMed

Kumar, Anoop; Sherlin, Herald J; Ramani, Pratibha; Natesan, Anuja; Premkumar, Priya

2015-01-01

Multinucleated giant cells (MNCs) form an integral part of numerous bone and soft tissue tumors, tumor-like lesions and are often associated with granulomas of immunological and nonimmunological origin. The presence of various types of giant cells depends on the lesions in which they are present which are difficult to be diagnosed under routine histological techniques. Immunohistochemistry can be used for a better diagnosis and understanding of the origin of various giant cells using various markers of immune response like human leukocyte antigen-DR (HLA-DR) and those expressed on monocytes and macrophages like CD 68 and leukocyte common antigen (LCA). The study group consisted of 10 cases of giant cell tumor (GCT) of long bones, tuberculous granuloma, and giant cell granuloma to evaluate and analyze the expression pattern of LCA, CD 68, and HLA-DR in various giant cell lesions. Strong expression of CD 68 was observed in 80% of the lesions, strong and moderate expression of CD 45 observed in 70% of the lesions among and within the groups. In contrast, HLA-DR demonstrated negative expression in 80% of cases except for tuberculous granuloma where all the 10 cases showed moderate to strong immunoreactivity. CD 68 and CD 45 expression was found in central giant cell granuloma, peripheral giant cell granuloma and GCT, suggesting the origin from mononuclear phagocyte system and considering their clinical behavior of osteoclast type. High expressivity of HLA-DR in tuberculous granulomas which is an essential factor for presentation of the microbial antigen to CD 4 helper cells thus reassuring the fact that they are up-regulated in response to infection.

Virome comparisons in wild-diseased and healthy captive giant pandas.

PubMed

Zhang, Wen; Yang, Shixing; Shan, Tongling; Hou, Rong; Liu, Zhijian; Li, Wang; Guo, Lianghua; Wang, Yan; Chen, Peng; Wang, Xiaochun; Feng, Feifei; Wang, Hua; Chen, Chao; Shen, Quan; Zhou, Chenglin; Hua, Xiuguo; Cui, Li; Deng, Xutao; Zhang, Zhihe; Qi, Dunwu; Delwart, Eric

2017-08-07

The giant panda (Ailuropoda melanoleuca) is a vulnerable mammal herbivore living wild in central China. Viral infections have become a potential threat to the health of these endangered animals, but limited information related to these infections is available. Using a viral metagenomic approach, we surveyed viruses in the feces, nasopharyngeal secretions, blood, and different tissues from a wild giant panda that died from an unknown disease, a healthy wild giant panda, and 46 healthy captive animals. The previously uncharacterized complete or near complete genomes of four viruses from three genera in Papillomaviridae family, six viruses in a proposed new Picornaviridae genus (Aimelvirus), two unclassified viruses related to posaviruses in Picornavirales order, 19 anelloviruses in four different clades of Anelloviridae family, four putative circoviruses, and 15 viruses belonging to the recently described Genomoviridae family were sequenced. Reflecting the diet of giant pandas, numerous insect virus sequences related to the families Iflaviridae, Dicistroviridae, Iridoviridae, Baculoviridae, Polydnaviridae, and subfamily Densovirinae and plant viruses sequences related to the families Tombusviridae, Partitiviridae, Secoviridae, Geminiviridae, Luteoviridae, Virgaviridae, and Rhabdoviridae; genus Umbravirus, Alphaflexiviridae, and Phycodnaviridae were also detected in fecal samples. A small number of insect virus sequences were also detected in the nasopharyngeal secretions of healthy giant pandas and lung tissues from the dead wild giant panda. Although the viral families present in the sick giant panda were also detected in the healthy ones, a higher proportion of papillomaviruses, picornaviruses, and anelloviruses reads were detected in the diseased panda. This viral survey increases our understanding of eukaryotic viruses in giant pandas and provides a baseline for comparison to viruses detected in future infectious disease outbreaks. The similar viral families detected in sick and healthy giant pandas indicate that these viruses result in commensal infections in most immuno-competent animals.

CHEMICAL ABUNDANCES IN FIELD RED GIANTS FROM HIGH-RESOLUTION H-BAND SPECTRA USING THE APOGEE SPECTRAL LINELIST

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

Smith, Verne V.; Cunha, Katia; Shetrone, Matthew D.

2013-03-01

High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory Fourier transform spectrometer, are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the Sloan Digital Sky Survey III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. The red giant sample studied here was chosen to probe which chemical elements can bemore » derived reliably from the H-band APOGEE spectral region. These red giants consist of two K-giants ({alpha} Boo and {mu} Leo), two M-giants ({beta} And and {delta} Oph), and one thermally pulsing asymptotic giant branch (TP-AGB) star of spectral type MS (HD 199799). Measured chemical abundances include the cosmochemically important isotopes {sup 12}C, {sup 13}C, {sup 14}N, and {sup 16}O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. The K and M giants exhibit the abundance signature of the first dredge-up of CN-cycle material, while the TP-AGB star shows clear evidence of the addition of {sup 12}C synthesized during {sup 4}He-burning thermal pulses and subsequent third dredge-up. A comparison of the abundances derived here with published values for these stars reveals consistent results to {approx}0.1 dex. The APOGEE spectral region and linelist is thus well suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants via high-resolution spectroscopy.« less

Fungal cell gigantism during mammalian infection.

PubMed

Zaragoza, Oscar; García-Rodas, Rocío; Nosanchuk, Joshua D; Cuenca-Estrella, Manuel; Rodríguez-Tudela, Juan Luis; Casadevall, Arturo

2010-06-17

The interaction between fungal pathogens with the host frequently results in morphological changes, such as hyphae formation. The encapsulated pathogenic fungus Cryptococcus neoformans is not considered a dimorphic fungus, and is predominantly found in host tissues as round yeast cells. However, there is a specific morphological change associated with cryptococcal infection that involves an increase in capsule volume. We now report another morphological change whereby gigantic cells are formed in tissue. The paper reports the phenotypic characterization of giant cells isolated from infected mice and the cellular changes associated with giant cell formation. C. neoformans infection in mice resulted in the appearance of giant cells with cell bodies up to 30 microm in diameter and capsules resistant to stripping with gamma-radiation and organic solvents. The proportion of giant cells ranged from 10 to 80% of the total lung fungal burden, depending on infection time, individual mice, and correlated with the type of immune response. When placed on agar, giant cells budded to produce small daughter cells that traversed the capsule of the mother cell at the speed of 20-50 m/h. Giant cells with dimensions that approximated those in vivo were observed in vitro after prolonged culture in minimal media, and were the oldest in the culture, suggesting that giant cell formation is an aging-dependent phenomenon. Giant cells recovered from mice displayed polyploidy, suggesting a mechanism by which gigantism results from cell cycle progression without cell fission. Giant cell formation was dependent on cAMP, but not on Ras1. Real-time imaging showed that giant cells were engaged, but not engulfed by phagocytic cells. We describe a remarkable new strategy for C. neoformans to evade the immune response by enlarging cell size, and suggest that gigantism results from replication without fission, a phenomenon that may also occur with other fungal pathogens.

Glucocorticoids for Management of Polymyalgia Rheumatica and Giant Cell Arteritis.

PubMed

Matteson, Eric L; Buttgereit, Frank; Dejaco, Christian; Dasgupta, Bhaskar

2016-02-01

Diagnosis of polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) is based on typical clinical, histologic, and laboratory features. Ultrasonographic imaging in PMR with assessment especially of subdeltoid bursitis can aid in diagnosis and in following response to treatment. In GCA, diagnosis and disease activity are supported with ultrasonographic, MRI, or [(18)F]fluorodeoxyglucose PET evaluation of large vessels. Glucocorticoids are the primary therapy for PMR and GCA. Methotrexate may be used in patients at high risk for glucocorticoid adverse effects and patients with frequent relapse or needing protracted therapy. Other therapeutic approaches including interleukin 6 antagonists are under evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

Nucleation and growth of the Naica giant gypsum crystals.

PubMed

Otálora, Fermín; García-Ruiz, JuanMa

2014-04-07

The Cave of Giant Crystals in the Naica mine (Mexico) is one of the most amazing displays of mineral beauty ever created in nature. In addition to the colossal crystals of gypsum, which in some cases exceed eleven meters in length and one meter in thickness, the scenery fashioned by the crystalline beams that thrust through the darkness of the cave from floor to ceiling with a luster like moonlight is a unique example of harmony based on crystal symmetry. We review the crystallogenesis of this remarkable and challenging phenomenon of mineralization near equilibrium that can be used to teach the basics of nucleation and crystal growth.

Emergence of macroscopic directed motion in populations of motile colloids

NASA Astrophysics Data System (ADS)

Bricard, Antoine; Caussin, Jean-Baptiste; Desreumaux, Nicolas; Dauchot, Olivier; Bartolo, Denis

2013-11-01

From the formation of animal flocks to the emergence of coordinated motion in bacterial swarms, populations of motile organisms at all scales display coherent collective motion. This consistent behaviour strongly contrasts with the difference in communication abilities between the individuals. On the basis of this universal feature, it has been proposed that alignment rules at the individual level could solely account for the emergence of unidirectional motion at the group level. This hypothesis has been supported by agent-based simulations. However, more complex collective behaviours have been systematically found in experiments, including the formation of vortices, fluctuating swarms, clustering and swirling. All these (living and man-made) model systems (bacteria, biofilaments and molecular motors, shaken grains and reactive colloids) predominantly rely on actual collisions to generate collective motion. As a result, the potential local alignment rules are entangled with more complex, and often unknown, interactions. The large-scale behaviour of the populations therefore strongly depends on these uncontrolled microscopic couplings, which are extremely challenging to measure and describe theoretically. Here we report that dilute populations of millions of colloidal rolling particles self-organize to achieve coherent motion in a unique direction, with very few density and velocity fluctuations. Quantitatively identifying the microscopic interactions between the rollers allows a theoretical description of this polar-liquid state. Comparison of the theory with experiment suggests that hydrodynamic interactions promote the emergence of collective motion either in the form of a single macroscopic `flock', at low densities, or in that of a homogenous polar phase, at higher densities. Furthermore, hydrodynamics protects the polar-liquid state from the giant density fluctuations that were hitherto considered the hallmark of populations of self-propelled particles. Our experiments demonstrate that genuine physical interactions at the individual level are sufficient to set homogeneous active populations into stable directed motion.

Evolution of the protolunar disk: Dynamics, cooling timescale and implantation of volatiles onto the Earth

NASA Astrophysics Data System (ADS)

Charnoz, Sébastien; Michaut, Chloé

2015-11-01

It is thought that the Moon accreted from the protolunar disk that was assembled after the last giant impact on Earth. Due to its high temperature, the protolunar disk may act as a thermochemical reactor in which the material is processed before being incorporated into the Moon. Outstanding issues like devolatilisation and istotopic evolution are tied to the disk evolution, however its lifetime, dynamics and thermodynamics are unknown. Here, we numerically explore the long term viscous evolution of the protolunar disk using a one dimensional model where the different phases (vapor and condensed) are vertically stratified. Viscous heating, radiative cooling, phase transitions and gravitational instability are accounted for whereas Moon's accretion is not considered for the moment. The viscosity of the gas, liquid and solid phases dictates the disk evolution. We find that (1) the vapor condenses into liquid in ∼10 years, (2) a large fraction of the disk mass flows inward forming a hot and compact liquid disk between 1 and 1.7 Earth's radii, a region where the liquid is gravitationally stable and can accumulate, (3) the disk finally solidifies in 103 to 105 years. Viscous heating is never balanced by radiative cooling. If the vapor phase is abnormally viscous, due to magneto-rotational instability for instance, most of the disk volatile components are transported to Earth leaving a disk enriched in refractory elements. This opens a way to form a volatile-depleted Moon and would suggest that the missing Moon's volatiles are buried today into the Earth. The disk cooling timescale may be long enough to allow for planet/disk isotopic equilibration. However large uncertainties on the disk physics remain because of the complexity of its multi-phased structure.

[Pathological and immunohistochemical analysis of giant cells of pancreas].

PubMed

Miyake, T; Suda, K; Yamamura, A; Tada, Y

1997-10-01

Multinucleated giant cells in the pancreas (five giant cell carcinomas, a mucinous cystadenocarcinoma attended with many osteoclast-like giant cells, 42 invasive ductal carcinomas and 29 chronic pancreatitises) were examined. Three types of multinucleated giant cell were identified: epithelial type, coexpressive type, mesenchymal type. Epithelial type expressed epithelial markers, such as keratin and EMA in 23 ductal carcinomas. Coexpressive type expressed both epithelial markers and mesenchymal marker vimentin was in four ductal carcinomas. Mesenchymal type expressed mesenchymal markers, vimentin and CD68 in four osteoclastoid type giant cell carcinomas, the mucinous cystadenocarcinoma, six ductal carcinomas and ten chronic pancreatitises. Epithelial and coexpressive type were considered to be epithelial neoplastic origin, those had bizarre appearance and transitional area from definite adenocarcinoma area. Vimentin expression is associated with sarcomatous proliferation. Mesenchymal type was considered to be nonneoplastic and a certain type of macrophage polykaryons.

Giant Pulse Phenomena in a High Gain Erbium Doped Fiber Amplifier

NASA Technical Reports Server (NTRS)

Li, Stephen X.; Merritt, Scott; Krainak, Michael A.; Yu, Anthony

2018-01-01

High gain Erbium Doped Fiber Amplifiers (EDFAs), while revolutionizing optical communications, remain vulnerable to optical damage when unseeded, e.g. due to nonlinear effects that produce random pulses with high peak power, i.e. giant pulses. Giant pulses can damage the components in a high gain EDFA or external components and systems coupled to the EDFA. We explore the conditions under which a reflective, polarization-maintaining (PM), core-pumped high gain EDFA generates giant pulses, provide details on conditions under which normal pulses evolve into giant pulses, and provide results on the transient effects of giant pulses on amplifier's fused-fiber couplers, an effect which we call Fiber Overload Induced Leakage (FOIL). While FOIL's effect on fused-fiber couplers is temporary, its damage to forward pump lasers in a high gain EDFA can be permanent.

Giant Pulse Phenomena in a High Gain Erbium Doped Fiber Amplifier

NASA Technical Reports Server (NTRS)

Li, Stephen X.; Merritt, Scott; Krainak, Michael A.; Yu, Anthony

2018-01-01

High gain Erbium Doped Fiber Amplifiers (EDFAs) are vulnerable to optical damage when unseeded, e.g. due to nonlinear effects that produce random, spontaneous Q-switched (SQS) pulses with high peak power, i.e. giant pulses. Giant pulses can damage either the components within a high gain EDFA or external components and systems coupled to the EDFA. We explore the conditions under which a reflective, polarization-maintaining (PM), core-pumped high gain EDFA generates giant pulses, provide details on the evolution of normal pulses into giant pulses, and provide results on the transient effects of giant pulses on an amplifier's fused-fiber couplers, an effect which we call Fiber Overload Induced Leakage (FOIL). While FOIL's effect on fused-fiber couplers is temporary, its damage to forward pump lasers in a high gain EDFA can be permanent.

Giant energy density in [001]-textured Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3 piezoelectric ceramics

NASA Astrophysics Data System (ADS)

Yan, Yongke; Cho, Kyung-Hoon; Maurya, Deepam; Kumar, Amit; Kalinin, Sergei; Khachaturyan, Armen; Priya, Shashank

2013-01-01

Pb(Zr,Ti)O3 (PZT) based compositions have been challenging to texture or grow in a single crystal form due to the incongruent melting point of ZrO2. Here we demonstrate the method for achieving 90% textured PZT-based ceramics and further show that it can provide highest known energy density in piezoelectric materials through enhancement of piezoelectric charge and voltage coefficients (d and g). Our method provides more than ˜5× increase in the ratio d(textured)/d(random). A giant magnitude of d.g coefficient with value of 59 000 × 10-15 m2 N-1 (comparable to that of the single crystal counterpart and 359% higher than that of the best commercial compositions) was obtained.

A catalog of rotational and radial velocities for evolved stars. V. Southern stars

NASA Astrophysics Data System (ADS)

De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M.

2014-01-01

Rotational and radial velocities have been measured for 1589 evolved stars of spectral types F, G, and K and luminosity classes IV, III, II, and Ib, based on observations carried out with the CORAVEL spectrometers. The precision in radial velocity is better than 0.30 km s-1 per observation, whereas rotational velocity uncertainties are typically 1.0 km s-1 for subgiants and giants and 2.0 km s-1 for class II giants and Ib supergiants. Based on observations collected at the Haute-Provence Observatory, Saint-Michel, France, and at the European Southern Observatory, La Silla, Chile.Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/561/A126

Supramolecular Synthons: Will Giant Rigid Superspheres Do?

PubMed Central

2016-01-01

For the first time, the concept of supramolecular synthons was applied to giant rigid superspheres based on pentaphosphaferrocene [CpRFe(η5-P5)] (R = Me, Et) and Cu(I) halides, which reach 2.1–3.0 nm in diameter. Two supramolecular synthons, σ–π and π–π, are discovered based on halogen···CpR and Cp*···Cp* specific interactions, respectively. The geometry of the synthons is reproducible in a series of crystal structures of various supramolecules. The σ–π synthon alone is realized more frequently for Br-containing superspheres. A combination of the σ–π and π–π synthons is more typical for Cl-containing supramolecules. Each supramolecule can bear up to nine synthons to give mostly 2D and 3D architectures. PMID:27081373

Comparative anatomy of the radial sesamoid bone in the polar bear (Ursus maritimus), the brown bear (Ursus arctos) and the giant panda (Ailuropoda melanoleuca).

PubMed

Endo, H; Makita, T; Sasaki, M; Arishima, K; Yamamoto, M; Hayashi, Y

1999-08-01

Since we have clarified the manipulation mechanism using the radial sesamoid (RS) in the giant panda (Ailuropoda melanoleuca), our aim in this study is to examine the position, shape and function of the RS morphologically, and to observe the attachment to the RS of the M. abductor pollicis longus and the M. opponens pollicis in the other Ursidae species. So, we focused on the carpus and manus of the polar bear (Ursus maritimus) and the brown bear (Ursus arctos) in this study. The RS was tightly articulated to the radial carpal, and could not adduct-abduct independently of the radial carpal. The M. abductor pollicis longus tendon and the M. opponens pollicis belly were attached to the RS, independently. In the polar bear, the deep concave and the flat surface were confirmed in attachment area for these two muscles. The morphological relationship between the RS and the M. abductor pollicis longus and the M. opponens pollicis in the two species of bears were essentially consistent with that in the giant panda. It also demonstrated that the manipulation mechanism of the giant panda has been completely based on the functional relationship between the small RS, and the M. abductor pollicis longus and the M. opponens pollicis in Ursidae species.

Manta birostris, predator of the deep? Insight into the diet of the giant manta ray through stable isotope analysis

PubMed Central

Couturier, Lydie I. E.; Marshall, Andrea D.; Richardson, Anthony J.; Weeks, Scarla J.; Bennett, Michael B.

2016-01-01

The characterization of diet for the giant manta ray Manta birostris has been problematic given their large-scale movement patterns and the difficulty in obtaining stomach contents from this species. The large majority of existing information is based on observational data limited to feeding events at the sea surface during daylight. Recently discovered aggregation sites for the giant manta ray off mainland Ecuador are some of the most accessible to date and provide a unique opportunity for researchers to gather much needed information on this elusive species. To assess how important surface zooplankton is to giant manta ray diet, we conducted stable isotope analysis (15N and 13C) on M. birostris muscle and surface zooplankton. Trophic position estimates placed M. birostris overall at a secondary consumer level of approximately 3.4 but there was large variation in δ15N and δ13C values among individuals. Manta birostris muscle tissue δ13C values were also not consistent with this species feeding predominantly on surface zooplankton and suggest that the majority of dietary intake is of mesopelagic origin. Given the conservative life history and fisheries pressure on large planktivores, knowledge of their trophic role and foraging strategies is essential to better understand their ecology and develop effective conservation measures. PMID:28018660

Enormous Li Enhancement Preceding Red Giant Phases in Low-mass Stars in the Milky Way Halo

NASA Astrophysics Data System (ADS)

Li, Haining; Aoki, Wako; Matsuno, Tadafumi; Bharat Kumar, Yerra; Shi, Jianrong; Suda, Takuma; Zhao, Gang

2018-01-01

Li abundances in the bulk of low-mass metal-poor stars are well reproduced by stellar evolution models adopting a constant initial abundance. However, a small number of stars have exceptionally high Li abundances, for which no convincing models have been established. We report on the discovery of 12 very metal-poor stars that have large excesses of Li, including an object having more than 100 times higher Li abundance than the values found in usual objects, which is the largest excess in metal-poor stars known to date. The sample is distributed over a wide range of evolutionary stages, including five unevolved stars, showing no clear abundance anomaly in other elements. The results indicate the existence of an efficient process to enrich Li in a small fraction of low-mass stars at the main-sequence or subgiant phase. The wide distribution of Li-rich stars along the red giant branch could be explained by the dilution of surface Li by mixing that occurs when the stars evolve into red giants. Our study narrows down the problem to be solved in order to understand the origins of Li excess found in low-mass stars, suggesting the presence of an unknown process that affects the surface abundances preceding red giant phases. This work is based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

How to deal with giant pituitary adenomas: transsphenoidal or transcranial, simultaneous or two-staged?

PubMed

Han, Sheng; Gao, Wei; Jing, Zhitao; Wang, Yunjie; Wu, Anhua

2017-04-01

Giant pituitary adenomas (diameter >4 cm) are a challenge to treat, and there is no consensus on the optimal surgical strategy. We report here our experience in surgical management of these lesions. Adult patients with giant pituitary adenomas (n = 62; 54 non-functioning and eight hormone-secreting adenomas) who underwent surgical resection at our hospital from 2009 to 2015 were retrospectively reviewed. Surgical and clinical outcomes were analyzed. Single transsphenoidal and transcranial approaches were used in 43 (69.4%) and four (6.5%) patients, respectively. A combined transsphenoidal and transcranial approach was used in 13 patients (20.9%) and in two patients (3.2%), a transcranial procedure was followed 3 months later by a transsphenoidal approach. Greater than 90% resection was achieved in 47 cases (75.8%). During a mean follow-up period of 46.9 months, 49 patients (79%) showed improved visual impairment scores, while none experienced visual deterioration. There was no post-operative hemorrhage or mortality. A total of 27 patients (43.5%) received adjuvant medical and/or radiation therapy. At last follow-up, eight patients (12.9%) had recurrence. For giant pituitary adenoma, the transsphenoidal and transcranial approaches should be combined flexibly based on the characteristics of the tumor. In certain cases, a simultaneous combined approach can maximize tumor extirpation and lower the risk of swelling and bleeding of the residual tumor.

Electrophysiological Recordings from the Giant Fiber System

PubMed Central

Allen, Marcus J

2010-01-01

The giant fiber system (GFS) of Drosophila is a well-characterized neuronal circuit that mediates the escape response in the fly. It is one of the few adult neural circuits from which electrophysiological recordings can be made routinely. This article describes a simple procedure for stimulating the giant fiber neurons directly in the brain of the adult fly and obtaining recordings from the output muscles of the giant fiber system. PMID:20647357

Three cases giant panda attack on human at Beijing Zoo.

PubMed

Zhang, Peixun; Wang, Tianbing; Xiong, Jian; Xue, Feng; Xu, Hailin; Chen, Jianhai; Zhang, Dianying; Fu, Zhongguo; Jiang, Baoguo

2014-01-01

Panda is regarded as Chinese national treasure. Most people always thought they were cute and just ate bamboo and had never imagined a panda could be vicious. Giant panda attacks on human are rare. There, we present three cases of giant panda attacks on humans at the Panda House at Beijing Zoo from September 2006 to June 2009 to warn people of the giant panda's potentially dangerous behavior.