On the chemical ladder of esters. Detection and formation of ethyl formate in the W51 e2 hot molecular core

NASA Astrophysics Data System (ADS)

Rivilla, V. M.; Beltrán, M. T.; Martín-Pintado, J.; Fontani, F.; Caselli, P.; Cesaroni, R.

2017-03-01

Context. In recent years, the detection of organic molecules with increasing complexity and potential biological relevance is opening the possibility to understand the formation of the building blocks of life in the interstellar medium. One of the families of molecules of substantial astrobiological interest are the esters. The simplest ester, methyl formate (CH3OCHO), is rather abundant in star-forming regions. The next step in the chemical complexity of esters is ethyl formate, C2H5OCHO. Despite the increase in sensitivity of current telescopes, the detection of complex molecules with more than ten atoms such as C2H5OCHO is still a challenge. Only two detections of this species have been reported so far, which strongly limits our understanding of how complex molecules are formed in the interstellar medium. New detections towards additional sources with a wide range of physical conditions are crucial to differentiate between competing chemical models based on dust grain surface and gas-phase chemistry. Aims: We have searched for ethyl formate towards the W51 e2 hot molecular core, one of the most chemically rich sources in the Galaxy and one of the most promising regions to study prebiotic chemistry, especially after the recent discovery of the P-O bond, key in the formation of DNA. Methods: We have analyzed a spectral line survey towards the W51 e2 hot molecular core, which covers 44 GHz in the 1, 2 and 3 mm bands, carried out with the IRAM 30 m telescope. Results: We report the detection of the trans and gauche conformers of ethyl formate. A local thermodynamic equilibrium analysis indicates that the excitation temperature is 78 ± 10 K and that the two conformers have similar source-averaged column densities of (2.0 ± 0.3) × 10-16 cm-2 and an abundance of 10-8. We compare for the first time the observed molecular abundances of ethyl formate with different competing chemical models based on grain surface and gas-phase chemistry. Conclusions: We propose that

CHEMICAL ANALYSIS OF A DIFFUSE CLOUD ALONG A LINE OF SIGHT TOWARD W51: MOLECULAR FRACTION AND COSMIC-RAY IONIZATION RATE

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

Indriolo, Nick; Neufeld, D. A.; Gerin, M.

2012-10-20

Absorption lines from the molecules OH{sup +}, H{sub 2}O{sup +}, and H{sup +} {sub 3} have been observed in a diffuse molecular cloud along a line of sight near W51 IRS2. We present the first chemical analysis that combines the information provided by all three of these species. Together, OH{sup +} and H{sub 2}O{sup +} are used to determine the molecular hydrogen fraction in the outskirts of the observed cloud, as well as the cosmic-ray ionization rate of atomic hydrogen. H{sup +} {sub 3} is used to infer the cosmic-ray ionization rate of H{sub 2} in the molecular interior ofmore » the cloud, which we find to be {zeta}{sub 2} = (4.8 {+-} 3.4) Multiplication-Sign 10{sup -16} s{sup -1}. Combining the results from all three species we find an efficiency factor-defined as the ratio of the formation rate of OH{sup +} to the cosmic-ray ionization rate of H-of {epsilon} = 0.07 {+-} 0.04, much lower than predicted by chemical models. This is an important step in the future use of OH{sup +} and H{sub 2}O{sup +} on their own as tracers of the cosmic-ray ionization rate.« less

Time Evolution of the Giant Molecular Cloud Mass Functions across Galactic Disks

NASA Astrophysics Data System (ADS)

Kobayashi, Masato I. N.; Inutsuka, Shu-Ichiro; Kobayashi, Hiroshi; Hasegawa, Kenji

2017-01-01

We formulate and conduct the time-integration of time evolution equation for the giant molecular cloud mass function (GMCMF) including the cloud-cloud collision (CCC) effect. Our results show that the CCC effect is only limited in the massive-end of the GMCMF and indicate that future high resolution and sensitivity radio observations may constrain giant molecular cloud (GMC) timescales by observing the GMCMF slope in the lower mass regime.

W49A: A Massive Molecular Cloud Forming a Massive Star Cluster in the Galactic Disk

NASA Astrophysics Data System (ADS)

Galvan-Madrid, Roberto; Liu, Hauyu Baobab; Pineda, Jaime E.; Zhang, Zhi-Yu; Ginsburg, Adam; Roman-Zuñiga, Carlos; Peters, Thomas

2015-08-01

I summarize our current results of the MUSCLE survey of W49A, the most luminous star formation region in the Milky Way. Our approach emphasizes multi-scale, multi-resolution imaging in dust, ionized-, and molecular gas, to trace the multiple gas components from <0.1 pc (core scale) all the way up to the scale of the entire giant molecular cloud (GMC), ˜100 pc. The 106 M⊙ GMC is structured in a radial network of filaments that converges toward the central 'hub' with ˜2x105 M⊙, which contains within a few pc a deeply embedded young massive cluster (YMC) of stellar mass ~5x104 M⊙. We also discuss the dynamics of the filamentary network, the role of turbulence in the formation of this YMC, and how objects like W49A can link Milky Way and extragalactic star formation relations.

51. Historic American Buildings Survey, Donald W. Dickensheets, Photographer. April ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

51. Historic American Buildings Survey, Donald W. Dickensheets, Photographer. April 10, 1940. UPPER PART OF CHURCH. (EAST ELEVATION). - San Xavier del Bac Mission, Mission Road, Tucson, Pima County, AZ

Chemistry and structure of giant molecular clouds in energetic environments

NASA Astrophysics Data System (ADS)

Anderson, Crystal Nicole

2016-09-01

Throughout the years many studies on Galactic star formation have been conducted. This resulted in the idea that giant molecular clouds (GMCs) are hierarchical in nature with substructures spanning a large range of sizes. The physical processes that determine how molecular clouds fragment, form clumps/cores and then stars depends strongly on both recent radiative and mechanical feed- back from massive stars and, on longer term, from enhanced cooling due to the buildup of metals. Radiative and mechanical energy input from stellar populations can alter subsequent star formation over a large part of a galaxy and hence is relevant to the evolution of galaxies. Much of our knowledge of star formation on galaxy wide scales is based on scaling laws and other parametric descriptions. But to understand the overall evolution of star formation in galaxies we need to watch the feedback processes at work on giant molecular cloud (GMC) scales. By doing this we can begin to answer how strong feedback environments change the properties of the substructure in GMCs. Tests of Galactic star formation theory to other galaxies has been a challenging process due to the lack of resolution with current instruments. Thus, only the nearest galaxies allow us to resolve GMCs and their substructures. The Large Magellanic Cloud (LMC), is one of the closest low metallicity dwarf galaxies (D˜ 50 kpc) and is close enough that current instruments can resolve the sub- structure of its GMCs to <1pc. The LMC has a star cluster located near the GMC, 30Doradus, producing high levels of far ultra violet (FUV) radiation in the inter- stellar medium (ISM). The dwarf galaxy, NGC 5253, is also a close low metallicity galaxy (3.8 Mpc) with a super star cluster, which appears to be composed of several newborn globular clusters, located within the center of the galaxy. These huge, compact collections of massive stars and their supernovae have the potential to dump large amounts of FUV radiation and momentum

Prevalence and molecular characterization of Cryptosporidium in giant panda (Ailuropoda melanoleuca) in Sichuan province, China.

PubMed

Wang, Tao; Chen, Zuqin; Xie, Yue; Hou, Rong; Wu, Qidun; Gu, Xiaobing; Lai, Weiming; Peng, Xuerong; Yang, Guangyou

2015-06-25

Cryptosporidium spp. have been extensively reported to cause significant diarrheal disease in humans and domestic animals. On the contrary, little information is available on the prevalence and characterization of Cryptosporidium in wild animals in China, especially in giant pandas. The aim of the present study was to detect Cryptosporidium infections and identify Cryptosporidium species at the molecular level in both captive and wild giant pandas in Sichuan province, China. Using a PCR approach, we amplified and sequenced the 18S rRNA gene from 322 giant pandas fecal samples (122 from 122 captive individuals and 200 collected from four habitats) in Sichuan province, China. The Cryptosporidium species/genotypes were identified via a BLAST comparison against published Cryptosporidium sequences available in GenBank followed by phylogenetic analysis. The results revealed that both captive and wild giant pandas were infected with a single Cryptosporidium species, C. andersoni, at a prevalence of 15.6% (19/122) and 0.5% (1/200) in captive and wild giant pandas, respectively. The present study revealed the existence of C. andersoni in both captive and wild giant panda fecal samples for the first time, and also provided useful fundamental data for further research on the molecular epidemiology and control of Cryptosporidium infection in giant pandas.

Molecular Cytogenetic Characterization of Tenosynovial Giant Cell Tumors

PubMed Central

Brandal, Petter; Bjerkehagen, Bodil; Heim, Sverre

2004-01-01

Abstract Tenosynovial giant cell tumor (TSGCT) is a disease of disputed etiology and pathogenesis. Some investigations indicate a neoplastic origin of the tumors; others indicate that they are polyclonal and inflammatory. The cytogenetic and molecular genetic features of TSGCTs are largely unknown, as only some 20 localized and 30 diffuse tumors with cytogenetic aberrations have been reported. The most common karyotypic aberrations have been trisomy for chromosomes 5 and 7 and translocations involving chromosomal area 1p11-13. We decided to screen the genomes of TSGCTs by comparative genomic hybridization (CGH) to perform interphase fluorescence in situ hybridization (IP-FISH), looking for numerical aberrations of chromosomes 1, 5, and 7, and to analyze the tumors for microsatellite instability. Except for two diffuse TSGCTs that came fresh to us, and which, by karyotyping, exhibited t(1;22)(p13;q12) and a t(1;1)(q21;p11) and +7, respectively, all studies had to be performed on formalin-fixed, paraffin-embedded material. DNA was extracted from 51 localized and nine diffuse TSGCTs. CGH was successful for 24 tumors, but none of them showed copy number changes. The IP-FISH studies showed trisomy 7 in 56% of the tumors (15/27), whereas chromosomes 1 and 5 seemed to be disomic in all TSGCTs. All informative tumors were wild-type by microsatellite instability analysis. PMID:15548367

Extreme star formation in the Milky Way: luminosity distributions of young stellar objects in W49A and W51

NASA Astrophysics Data System (ADS)

Eden, D. J.; Moore, T. J. T.; Urquhart, J. S.; Elia, D.; Plume, R.; König, C.; Baldeschi, A.; Schisano, E.; Rigby, A. J.; Morgan, L. K.; Thompson, M. A.

2018-07-01

We have compared the star-formation properties of the W49A and W51 regions by using far-infrared data from the Herschel infrared Galactic Plane Survey (Hi-GAL) and 850-μm observations from the James Clerk Maxwell Telescope (JCMT) to obtain luminosities and masses, respectively, of associated compact sources. The former are infrared luminosities from the catalogue of Elia et al., while the latter are from the JCMT Plane survey source catalogue as well as measurements from new data. The clump-mass distributions of the two regions are found to be consistent with each other, as are the clump-formation efficiency and star-formation efficiency analogues. However, the frequency distributions of the luminosities of the young stellar objects are significantly different. While the luminosity distribution in W51 is consistent with Galaxy-wide samples, that of W49A is top heavy. The differences are not dramatic and are concentrated in the central regions of W49A. However, they suggest that physical conditions there, which are comparable in part to those in extragalactic starbursts, are significantly affecting the star-formation properties or evolution of the dense clumps in the region.

Extreme star formation in the Milky Way: Luminosity distributions of young stellar objects in W49A and W51

NASA Astrophysics Data System (ADS)

Eden, D. J.; Moore, T. J. T.; Urquhart, J. S.; Elia, D.; Plume, R.; König, C.; Baldeschi, A.; Schisano, E.; Rigby, A. J.; Morgan, L. K.; Thompson, M. A.

2018-03-01

We have compared the star-formation properties of the W49A and W51 regions by using far-infrared data from the Herschel infrared Galactic Plane Survey (Hi-GAL) and 850-μm observations from the James Clerk Maxwell Telescope (JCMT) to obtain luminosities and masses, respectively, of associated compact sources. The former are infrared luminosities from the catalogue of Elia et al. (2017), while the latter are from the JCMT Plane survey source catalogue as well as measurements from new data. The clump-mass distributions of the two regions are found to be consistent with each other, as are the clump-formation efficiency and star-formation efficiency analogues. However, the frequency distributions of the luminosities of the young stellar objects are significantly different. While the luminosity distribution in W51 is consistent with Galaxy-wide samples, that of W49A is top-heavy. The differences are not dramatic, and are concentrated in the central regions of W49A. However, they suggest that physical conditions there, which are comparable in part to those in extragalactic starbursts, are significantly affecting the star-formation properties or evolution of the dense clumps in the region.

The dependence of stellar age distributions on giant molecular cloud environment

NASA Astrophysics Data System (ADS)

Dobbs, C. L.; Pringle, J. E.; Naylor, T.

2014-01-01

In this Letter, we analyse the distributions of stellar ages in giant molecular clouds (GMCs) in spiral arms, interarm spurs and at large galactic radii, where the spiral arms are relatively weak. We use the results of numerical simulations of galaxies, which follow the evolution of GMCs and include star particles where star formation events occur. We find that GMCs in spiral arms tend to have predominantly young (<10 Myr) stars. By contrast, clouds which are the remainders of spiral arm giant molecular asssociations that have been sheared into interarm GMCs contain fewer young (<10 Myr) stars and more ˜20 Myr stars. We also show that clouds which form in the absence of spiral arms, due to local gravitational and thermal instabilities, contain preferentially young stars. We propose that the age distributions of stars in GMCs will be a useful diagnostic to test different cloud evolution scenarios, the origin of spiral arms and the success of numerical models of galactic star formation. We discuss the implications of our results in the context of Galactic and extragalactic molecular clouds.

THE SEARCH FOR A COMPLEX MOLECULE IN A SELECTED HOT CORE REGION: A RIGOROUS ATTEMPT TO CONFIRM TRANS-ETHYL METHYL ETHER TOWARD W51 e1/e2

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

Carroll, P. Brandon; McGuire, Brett A.; Blake, Geoffrey A.

2015-01-20

An extensive search has been conducted to confirm transitions of trans-ethyl methyl ether (tEME, C{sub 2}H{sub 5}OCH{sub 3}), toward the high-mass star forming region W51 e1/e2 using the 12 m Telescope of the Arizona Radio Observatory at wavelengths from 2 mm and 3 mm. In short, we cannot confirm the detection of tEME toward W51 e1/e2 and our results call into question the initial identification of this species by Fuchs et al. Additionally, re-evaluation of the data from the original detection indicates that tEME is not present toward W51 e1/e2 in the abundance reported by Fuchs and colleagues. Typical peak-to-peak noise levels for themore » present observations of W51 e1/e2 were between 10 and 30 mK, yielding an upper limit of the tEME column density of ≤1.5 × 10{sup 15} cm{sup –2}. This would make tEME at least a factor of two times less abundant than dimethyl ether (CH{sub 3}OCH{sub 3}) toward W51 e1/e2. We also performed an extensive search for this species toward the high-mass star forming region Sgr B2(N-LMH) with the National Radio Astronomy Observatory 100 m Green Bank Telescope. No transitions of tEME were detected and we were able to set an upper limit to the tEME column density of ≤4 × 10{sup 14} cm{sup –2} toward this source. Thus, we are able to show that tEME is not a new molecular component of the interstellar medium and that an exacting assessment must be carried out when assigning transitions of new molecular species to astronomical spectra to support the identification of large organic interstellar molecules.« less

Molecular Cloud Structures and Massive Star Formation in N159

NASA Astrophysics Data System (ADS)

Nayak, O.; Meixner, M.; Fukui, Y.; Tachihara, K.; Onishi, T.; Saigo, K.; Tokuda, K.; Harada, R.

2018-02-01

The N159 star-forming region is one of the most massive giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC). We show the 12CO, 13CO, CS molecular gas lines observed with ALMA in N159 west (N159W) and N159 east (N159E). We relate the structure of the gas clumps to the properties of 24 massive young stellar objects (YSOs) that include 10 newly identified YSOs based on our search. We use dendrogram analysis to identify properties of the molecular clumps, such as flux, mass, linewidth, size, and virial parameter. We relate the YSO properties to the molecular gas properties. We find that the CS gas clumps have a steeper size–linewidth relation than the 12CO or 13CO gas clumps. This larger slope could potentially occur if the CS gas is tracing shocks. The virial parameters of the 13CO gas clumps in N159W and N159E are low (<1). The threshold for massive star formation in N159W is 501 M ⊙ pc‑2, and the threshold for massive star formation in N159E is 794 M ⊙ pc‑2. We find that 13CO is more photodissociated in N159E than N159W. The most massive YSO in N159E has cleared out a molecular gas hole in its vicinity. All the massive YSO candidates in N159E have a more evolved spectral energy distribution type in comparison to the YSO candidates in N159W. These differences lead us to conclude that the giant molecular cloud complex in N159E is more evolved than the giant molecular cloud complex in N159W.

Chromosome banding in amphibia. XXIII. Giant W sex chromosomes and extremely small genomes in Eleutherodactylus euphronides and Eleutherodactylus shrevei (Anura, Leptodactylidae).

PubMed

Schmid, M; Feichtinger, W; Steinlein, C; Rupprecht, A; Haaf, T; Kaiser, H

2002-01-01

Highly differentiated, heteromorphic ZZ female symbol /ZW male symbol sex chromosomes were found in the karyotypes of the neotropical leptodactylid frogs Eleutherodactylus euphronides and E. shrevei. The W chromosomes are the largest heterochromatic, female-specific chromosomes so far discovered in the class Amphibia. The analyses of the banding patterns with AT- and GC base-pair specific fluorochromes show that the constitutive heterochromatin in the giant W chromosomes consists of various categories of repetitive DNA sequences. The W chromosomes of both species are similar in size, morphology and banding patterns, whereas their Z chromosomes exhibit conspicuous differences. In the cell nuclei of female animals, the W chromosomes form very prominent chromatin bodies (W chromatin). DNA flow cytometric measurements demonstrate clear differences in the DNA content of male and female erythrocytes caused by the giant W chromosome, and also shows that these Eleutherodactylus genomes are among the smallest of all amphibian genomes. The importance of the heteromorphic ZW sex chromosomes for the study of Z-linked genes, the similarities and differences of the two karyotypes, and the significance of the exceptionally small genomes are discussed. Copyright 2002 S. Karger AG, Basel

Giant rectification in graphene nanoflake molecular devices with asymmetric graphene nanoribbon electrodes

NASA Astrophysics Data System (ADS)

Ji, Xiao-Li; Xie, Zhen; Zuo, Xi; Zhang, Guang-Ping; Li, Zong-Liang; Wang, Chuan-Kui

2016-09-01

By applying density functional theory based nonequilibrium Green's function method, we theoretically investigate the electron transport properties of a zigzag-edged trigonal graphene nanoflake (ZTGNF) sandwiched between two asymmetric zigzag graphene nanoribbon (zGNR) and armchair graphene nanoribbon (aGNR) electrodes with carbon atomic chains (CACs) as the anchoring groups. Significant rectifying effects have been observed for these molecular devices in low bias voltage regions. Interestingly, the rectifying performance of molecular devices can be optimized by changing the width of the aGNR electrode and the number of anchoring CACs. Especially, the molecular device displays giant rectification ratios up to the order of 104 when two CACs are used as the anchoring group between the ZTGNF and the right aGNR electrode. Further analysis indicates that the asymmetric shift of the perturbed molecular energy levels and the spatial parity of the electron wavefunctions in the electrodes around the Fermi level play key roles in determining the rectification performance. And the spatial distributions of tunneling electron wavefunctions under negative bias voltages can be modified to be very localized by changing the number of anchoring CACs, which is found to be the origin of the giant rectification ratios.

Excitation and Disruption of a Giant Molecular Cloud by the Sepurnova Remnant 3C 391

NASA Technical Reports Server (NTRS)

Reach, W. T.; Rho, J.

1998-01-01

The ambient molecular gas at the distance of the remnant comprises a giant molecular cloud whose edge is closely parallel to a ridge of bright non-thermal radio continuum, which evidently delineates the blast-wave into the cloud.

Dense cores of GMAs in M51

NASA Astrophysics Data System (ADS)

Egusa, Fumi; Koda, J.; Scoville, N. Z.

2010-01-01

We present sensitive and high angular resolution CO(1-0) data obtained by CARMA observations toward the nearby grand-design spiral galaxy M51. From the data, Giant Molecular Associations (GMAs) in a spiral arm are found to be resolved into a few small clumps with mass of 106 Msun and size of 40 pc. As the densities of these clumps are estimated to be larger than 300 cm-3, we regard them as dense cores of GMAs. If GMAs were just confusion of Giant Molecular Clouds (GMCs) whose typical mass and size are almost the same as those of the detected clumps, we should have detected tens or more of them per each GMA considering the sensitivity of our data. However, only one or two cores are found in each GMA, indicating that GMAs are not ensembles of GMCs but are discrete smooth structures. This result is consistent with the conclusion by Koda et al. (2009), who worked on lower resolution CO data of M51. In addition, we have found that these cores are located downstream of the spiral arm. This suggests that the core formation of GMAs and their evolution are triggered by the spiral structure, or density waves. Our high resolution data reveal the inner structure of GMAs and its relationships to the global structure for the first time in grand-design spiral galaxies.

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.

Positional cloning of the sex-linked giant egg (Ge) locus in the silkworm, Bombyx mori.

PubMed

Fujii, T; Abe, H; Kawamoto, M; Banno, Y; Shimada, T

2015-04-01

The giant egg (Ge) locus is a Z-linked mutation that leads to the production of large eggs. Cytological observations suggest that an unusual translocation of a large fragment of the W chromosome bearing a putative egg size-determining gene, Esd, gave rise to giant egg mutants. However, there is currently no molecular evidence confirming either a W-Z translocation or the presence of Esd on the W chromosome. To elucidate the origin of giant egg mutants, we performed positional cloning. We observed that the Bombyx mori. orthologue of the human Phytanoyl-CoA dioxygenase domain containing 1 gene (PHYHD1) is disrupted in giant egg mutants. PHYHD1 is highly conserved in eukaryotes and is predicted to be a Fe(II) and 2-oxoglutarate-dependent oxygenase. Exon skipping in one of the two available Ge mutants is probably caused by the insertion of a non-long terminal repeat transposon into intron 4 in the vicinity of the 5' splice site. Segmental duplication in Ge(2) , an independent allele, was caused by unequal recombination between short interspersed elements inserted into introns 3 and 5. Our results indicate that (1) Bombyx PHYHD1 is responsible for the Ge mutants and that (2) the Ge locus is unrelated to the W-linked putative Esd. To our knowledge, this is the first report describing the phenotypic defects caused by mutations in PHYHD1 orthologues. © 2014 The Royal Entomological Society.

Giant molecular clouds as regions of particle acceleration

NASA Technical Reports Server (NTRS)

Dogiel, V. A.; Gurevich, A. V.; Istomin, Y. N.; Zybin, K. A.

1985-01-01

One of the most interesting results of investigations carried out on the satellites SAS-II and COS-B is the discovery of unidentified discrete gamma sources. Possibly a considerable part of them may well be giant molecular clouds. Gamma emission from clouds is caused by the processes with participation of cosmic rays. The estimation of the cosmic ray density in clouds has shown that for the energy E approx. = I GeV their density can 10 to 1000 times exceed the one in intercloud space. We have made an attempt to determine the mechanism which could lead to the increase in the cosmic ray density in clouds.

VizieR Online Data Catalog: Mapping spectral line survey toward W51 in 3mm (Watanabe+, 2017)

NASA Astrophysics Data System (ADS)

Watanabe, Y.; Nishimura, Y.; Harada, N.; Sakai, N.; Shimonishi, T.; Aikawa, Y.; Kawamura, A.; Yamamoto, S.

2018-04-01

Observations were carried out with the Mopra 22m telescope in 2013 October and 2014 August and September. An on-the-fly (OTF) mapping method was employed to cover the 25'x30' area of W51 centered at (l,b)=(49.4902°,-0.2622°) in the Galactic coordinate. The area corresponds to 39pcx47pc at the distance of W51. Three frequency settings were observed to cover the frequency ranges of 85.2-101.1GHz and 107.0-114.9GHz. (3 data files).

Targeting CYP51 for drug design by the contributions of molecular modeling.

PubMed

Rabelo, Vitor W; Santos, Taísa F; Terra, Luciana; Santana, Marcos V; Castro, Helena C; Rodrigues, Carlos R; Abreu, Paula A

2017-02-01

CYP51 is an enzyme of sterol biosynthesis pathway present in animals, plants, protozoa and fungi. This enzyme is described as an important drug target that is still of interest. Therefore, in this work, we reviewed the structure and function of CYP51 and explored the molecular modeling approaches for the development of new antifungal and antiprotozoans that target this enzyme. Crystallographic structures of CYP51 of some organisms have already been described in the literature, which enable the construction of homology models of other organisms' enzymes and molecular docking studies of new ligands. The binding mode and interactions of some new series of azoles with antifungal or antiprotozoan activities has been studied and showed important residues of the active site. Molecular modeling is an important tool to be explored for the discovery and optimization of CYP51 inhibitors with better activities, pharmacokinetics, and toxicological profiles. © 2016 Société Française de Pharmacologie et de Thérapeutique.

Molecular Mechanisms Underlying γ-Aminobutyric Acid (GABA) Accumulation in Giant Embryo Rice Seeds.

PubMed

Zhao, Guo-Chao; Xie, Mi-Xue; Wang, Ying-Cun; Li, Jian-Yue

2017-06-21

To uncover the molecular mechanisms underlying GABA accumulation in giant embryo rice seeds, we analyzed the expression levels of GABA metabolism genes and contents of GABA and GABA metabolic intermediates in developing grains and germinated brown rice of giant embryo rice 'Shangshida No. 5' and normal embryo rice 'Chao2-10' respectively. In developing grains, the higher GABA contents in 'Shangshida No. 5' were accompanied with upregulation of gene transcripts and intermediate contents in the polyamine pathway and downregulation of GABA catabolic gene transcripts, as compared with those in 'Chao2-10'. In germinated brown rice, the higher GABA contents in 'Shangshida No. 5' were parallel with upregulation of OsGAD and polyamine pathway gene transcripts and Glu and polyamine pathway intermediate contents and downregulation of GABA catabolic gene transcripts. These results are the first to indicate that polyamine pathway and GABA catabolic genes play a crucial role in GABA accumulation in giant embryo rice seeds.

Revealing W51C as a Cosmic-Ray source using Fermi-LAT data

DOE PAGES

Jogler, T.; Funk, S.

2016-01-10

Here, supernova remnants (SNRs) are commonly believed to be the primary sources of Galactic cosmic rays. Despite intensive study of the non-thermal emission of many SNRs the identification of the accelerated particle type relies heavily on assumptions of ambient-medium parameters that are only loosely constrained. Compelling evidence of hadronic acceleration can be provided by detecting a strong roll-off in the secondary γ-ray spectrum below themore » $${\\pi }^{0}$$ production threshold energy of about 135 MeV, the so called "pion bump." Here we use five years of Fermi-Large Area Telescope data to study the spectrum above 60 MeV of the middle-aged SNR W51C. A clear break in the power-law γ-ray spectrum at $${E}_{{\\rm{break}}}=290\\pm 20\\;{\\rm{MeV}}$$ is detected with $$9\\sigma $$ significance and we show that this break is most likely associated with the energy production threshold of $${\\pi }^{0}$$mesons. A high-energy break in the γ-ray spectrum at about 2.7 GeV is found with $$7.5\\sigma $$ significance. The spectral index at energies beyond this second break is $${{\\rm{\\Gamma }}}_{2}={2.52}_{-0.07}^{+0.06}$$ and closely matches the spectral index derived by the MAGIC Collaboration above 75 GeV. Therefore our analysis provides strong evidence to explain the γ-ray spectrum of W51C by a single particle population of protons with a momentum spectrum best described by a broken power law with break momentum $${p}_{{\\rm{break}}}\\sim 80\\;{\\rm{G}}{\\rm{e}}{\\rm{V}}/c.$$ W51C is the third middle-aged SNR that displays compelling evidence for cosmic-ray acceleration and thus strengthens the case of SNRs as the main source of Galactic cosmic rays.« less

A Herschel-SPIRE Survey of the MonR2 Giant Molecular Cloud

NASA Astrophysics Data System (ADS)

Pokhrel, Riwaj; Gutermuth, Robert; Ali, Babar; Megeath, Thomas; Pipher, Judith; Myers, Philip; Fischer, William; Henning, Thomas; Wolk, Scott; Allen, Lori; Tobin, John

2015-08-01

We present a new survey of the MonR2 giant molecular cloud with SPIRE on the Herschel Space Observatory. We cross-calibrated SPIRE data with Planck-HFI and accounted for its absolute offset and zero point correction. We fixed emissivity with the help of flux-error and flux ratio plots. As the best representation of cold dusty molecular clouds, we did greybody fits of the SEDs. We studied the nature of distribution of column densities above and below certain critical limit, followed by the mass and temperature distributions for different regions. We used dendrograms as a technique to study the hierarchical structures in the GMC.

A Herschel-SPIRE Survey of the MonR2 Giant Molecular Cloud

NASA Astrophysics Data System (ADS)

Pokhrel, Riwaj; Gutermuth, Robert A.; Ali, Babar; Megeath, S. Thomas; Pipher, Judith; Myers, Philip C.; Fischer, William J.; Henning, Thomas; Wolk, Scott J.; Allen, Lori; Tobin, John J.

2014-06-01

We present a new survey of the MonR2 giant molecular cloud with SPIRE on the Herschel Space Observatory. We cross-calibrated SPIRE data with Planck-HFI and accounted for its absolute offset and zero point correction. We fixed emissivity with the help of flux-error and flux ratio plots. As the best representation of cold dusty molecular clouds, we did greybody fits of the SEDs. We studied the nature of distribution of column densities above and below certain critical limit, followed by the mass and temperature distributions for different regions. We isolated the filaments and studied radial column density profile in this cloud.

40 CFR 51.901 - Applicability of part 51.

Code of Federal Regulations, 2014 CFR

2014-07-01

... in subparts A through W of part 51 apply to areas for purposes of the 8-hour NAAQS to the extent they... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Applicability of part 51. 51.901 Section 51.901 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 51.901 - Applicability of part 51.

Code of Federal Regulations, 2012 CFR

2012-07-01

... in subparts A through W of part 51 apply to areas for purposes of the 8-hour NAAQS to the extent they... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Applicability of part 51. 51.901 Section 51.901 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 51.901 - Applicability of part 51.

Code of Federal Regulations, 2011 CFR

2011-07-01

... in subparts A through W of part 51 apply to areas for purposes of the 8-hour NAAQS to the extent they... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Applicability of part 51. 51.901 Section 51.901 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 51.901 - Applicability of part 51.

Code of Federal Regulations, 2013 CFR

2013-07-01

... in subparts A through W of part 51 apply to areas for purposes of the 8-hour NAAQS to the extent they... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Applicability of part 51. 51.901 Section 51.901 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 51.901 - Applicability of part 51.

Code of Federal Regulations, 2010 CFR

2010-07-01

... in subparts A through W of part 51 apply to areas for purposes of the 8-hour NAAQS to the extent they... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Applicability of part 51. 51.901 Section 51.901 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

A High-Mass Cold Core in the Auriga-California Giant Molecular Cloud

NASA Astrophysics Data System (ADS)

Magnus McGehee, Peregrine; Paladini, Roberta; Pelkonen, Veli-Matti; Toth, Viktor; Sayers, Jack

2015-08-01

The Auriga-California Giant Molecular Cloud is noted for its relatively low star formation rate, especially at the high-mass end of the Initial Mass Function. We combine maps acquired by the Caltech Submillimeter Observatory's Multiwavelength Submillimeter Inductance Camera [MUSIC] in the wavelength range 0.86 to 2.00 millimeters with Planck and publicly-available Herschel PACS and SPIRE data in order to characterize the mass, dust properties, and environment of the bright core PGCC G163.32-8.41.

Evidence for Lignin Oxidation by the Giant Panda Fecal Microbiome

PubMed Central

Zhou, Peng; Chang, Fei; Hong, Yuzhi; Zhang, Xuecheng; Peng, Hui; Xiao, Yazhong

2012-01-01

The digestion of lignin and lignin-related phenolic compounds from bamboo by giant pandas has puzzled scientists because of the lack of lignin-degrading genes in the genome of the bamboo-feeding animals. We constructed a 16S rRNA gene library from the microorganisms derived from the giant panda feces to identify the possibility for the presence of potential lignin-degrading bacteria. Phylogenetic analysis showed that the phylotypes of the intestinal bacteria were affiliated with the phyla Proteobacteria (53%) and Firmicutes (47%). Two phylotypes were affiliated with the known lignin-degrading bacterium Pseudomonas putida and the mangrove forest bacteria. To test the hypothesis that microbes in the giant panda gut help degrade lignin, a metagenomic library of the intestinal bacteria was constructed and screened for clones that contained genes encoding laccase, a lignin-degrading related enzyme. A multicopper oxidase gene, designated as lac51, was identified from a metagenomic clone. Sequence analysis and copper content determination indicated that Lac51 is a laccase rather than a metallo-oxidase and may work outside its original host cell because it has a TAT-type signal peptide and a transmembrane segment at its N-terminus. Lac51 oxidizes a variety of lignin-related phenolic compounds, including syringaldazine, 2,6-dimethoxyphenol, ferulic acid, veratryl alcohol, guaiacol, and sinapinic acid at conditions that simulate the physiologic environment in giant panda intestines. Furthermore, in the presence of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), syringic acid, or ferulic acid as mediators, the oxidative ability of Lac51 on lignin was promoted. The absorbance of lignin at 445 nm decreased to 36% for ABTS, 51% for syringic acid, and 51% for ferulic acid after incubation for 10 h. Our findings demonstrate that the intestinal bacteria of giant pandas may facilitate the oxidation of lignin moieties, thereby clarifying the digestion of bamboo

Abundances in red giant stars - Carbon and oxygen isotopes in carbon-rich molecular envelopes

NASA Technical Reports Server (NTRS)

Wannier, P. G.; Sahai, R.

1987-01-01

Millimeter-wave observations have been made of isotopically substituted CO toward the envelopes of 11 carbon-rich stars. In every case, C-13O was detected and model calculations were used to estimate the C-12/C-13 abundance ratio. C-17O was detected toward three, and possibly four, envelopes, with sensitive upper limits for two others. The CO-18 variant was detected in two envelopes. New results include determinations of oxygen isotopic ratios in the two carbon-rich protoplanetary nebulae CRL 26688 and CRL 618. As with other classes of red giant stars, the carbon-rich giants seem to be significantly, though variably, enriched in O-17. These results, in combination with observations in interstellar molecular clouds, indicate that current knowledge of stellar production of the CNO nuclides is far from satisfactory.

Submillimeter Array {sup 12}CO (2-1) Imaging of the NGC 6946 Giant Molecular Clouds

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

Wu, Ya-Lin; Sakamoto, Kazushi; Pan, Hsi-An, E-mail: yalinwu@email.arizona.edu

2017-04-10

We present a {sup 12}CO (2–1) mosaic map of the spiral galaxy NGC 6946 by combining data from the Submillimeter Array and the IRAM 30 m telescope. We identify 390 giant molecular clouds (GMCs) from the nucleus to 4.5 kpc in the disk. GMCs in the inner 1 kpc are generally more luminous and turbulent, some of which have luminosities >10{sup 6} K km s{sup −1} pc{sup 2} and velocity dispersions >10 km s{sup −1}. Large-scale bar-driven dynamics likely regulate GMC properties in the nuclear region. Similar to the Milky Way and other disk galaxies, GMC mass function of NGCmore » 6946 has a shallower slope (index > −2) in the inner region, and a steeper slope (index < −2) in the outer region. This difference in mass spectra may be indicative of different cloud formation pathways: gravitational instabilities might play a major role in the nuclear region, while cloud coalescence might be dominant in the outer disk. Finally, the NGC 6946 clouds are similar to those in M33 in terms of statistical properties, but they are generally less luminous and turbulent than the M51 clouds.« less

Clustering the Orion B giant molecular cloud based on its molecular emission

PubMed Central

Bron, Emeric; Daudon, Chloé; Pety, Jérôme; Levrier, François; Gerin, Maryvonne; Gratier, Pierre; Orkisz, Jan H.; Guzman, Viviana; Bardeau, Sébastien; Goicoechea, Javier R.; Liszt, Harvey; Öberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal

2017-01-01

Context Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). Aims We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. Methods We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional Probability Density Function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. Results A clustering analysis based only on the J = 1 – 0 lines of three isotopologues of CO proves suffcient to reveal distinct density/column density regimes (nH ~ 100 cm−3, ~ 500 cm−3, and > 1000 cm−3), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J = 1 − 0 line of HCO+ and the N = 1 − 0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO+ and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO+ intensity ratio in UV-illuminated regions. Finer distinctions in density classes (nH ~ 7 × 103 cm−3 ~ 4 × 104 cm−3) for the

Clustering the Orion B giant molecular cloud based on its molecular emission.

PubMed

Bron, Emeric; Daudon, Chloé; Pety, Jérôme; Levrier, François; Gerin, Maryvonne; Gratier, Pierre; Orkisz, Jan H; Guzman, Viviana; Bardeau, Sébastien; Goicoechea, Javier R; Liszt, Harvey; Öberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal

2018-02-01

Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional Probability Density Function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. A clustering analysis based only on the J = 1 - 0 lines of three isotopologues of CO proves suffcient to reveal distinct density/column density regimes ( n H ~ 100 cm -3 , ~ 500 cm -3 , and > 1000 cm -3 ), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J = 1 - 0 line of HCO + and the N = 1 - 0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO + and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO + intensity ratio in UV-illuminated regions. Finer distinctions in density classes ( n H ~ 7 × 10 3 cm -3 ~ 4 × 10 4 cm -3 ) for the densest regions are also

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.

Isolation and Preliminary Screening of a Weissella confusa Strain from Giant Panda (Ailuropoda melanoleuca).

PubMed

Xiong, Lvchen; Ni, Xueqin; Niu, Lili; Zhou, Yi; Wang, Qiang; Khalique, Abdul; Liu, Qian; Zeng, Yan; Shu, Gang; Pan, Kangcheng; Jing, Bo; Zeng, Dong

2018-04-13

Weissella confusa has recently received attention for its probiotic potential. Some W. confusa and Weissella cibaria strains isolated from fermented foods show favorable probiotic effects. However, the probiotic properties of W. confusa isolated from giant panda remain unreported to date. Thus, this study isolated a W. confusa strain from giant panda feces and then investigated its characteristics and probiotic properties. A lactic acid bacteria strain was isolated from giant panda fecal samples. The isolated strain was screened by in vitro probiotic property tests, including in vitro antimicrobial test, antioxidant test, surface hydrophobicity, and stress resistance. On the basis of biochemical identification and 16S rDNA sequencing, the W. confusa strain was identified as BSP201703. This Weissella confusa strain can survive at pH 2 and 0.3% (w/v) concentration of bile salt environment and inhibit common intestinal pathogens. It also possesses an in vitro antioxidant capacity, a high auto-aggregation ability, and a high surface hydrophobicity. BSP201703 might serve as a probiotic to giant pandas.

Giant surfactants of poly(ethylene oxide)- b-polystyrene-(molecular nanoparticle): nanoparticle-driven self-assembly with sub-10-nm nanostructures in thin films

NASA Astrophysics Data System (ADS)

Hsu, Chih-Hao; Lin, Zhiwei; Dong, Xue-Hui; Hsieh, I.-Fan; Cheng, Stephen Z. D.

2014-03-01

Giant surfactants are built upon precisely attaching shape- and volume-persistent molecular nanoparticles (MNP) to polymeric flexible tails. The unique class of self-assembling materials, giant surfactants, has been demonstrated to form self-assembled ordered nanostructures, and their self-assembly behaviors are remarkably sensitive to primary chemical structures. In this work, two sets of giant surfactants with functionalized MNP attached to diblock copolymer tails were studied in thin films. Carboxylic acid-functionalized [60]fullerene (AC60) tethered with PEO- b-PS (PEO-PS-AC60) represents an ABA' (hydrophilic-hydrophobic-hydrophilic) giant surfactant, and fluoro-functionalized polyhedral oligomeric silsesquioxane (FPOSS) tethered with PEO- b-PS (PEO-PS-FPOSS) represents an ABC (hydrophilic-hydrophobic-omniphobic) one. The dissimilar chemical natures of the MNPs result in different arrangement of MNPs in self-assembled structures, the dispersion of AC60 in PEO domain and the single domain of FPOSS. Moreover, the chemically bonded MNPs could induce the originally disordered small molecular PEO- b-PS to form ordered cylindrical and lamellar structure, as evidenced by TEM and GISAXS, leading to sub-10-nm nanostructures of copolymer in the thin film state.

Giant magnetoresistive biosensors for molecular diagnosis: surface chemistry and assay development

NASA Astrophysics Data System (ADS)

Yu, Heng; Osterfeld, Sebastian J.; Xu, Liang; White, Robert L.; Pourmand, Nader; Wang, Shan X.

2008-08-01

Giant magnetoresistive (GMR) biochips using magnetic nanoparticle as labels were developed for molecular diagnosis. The sensor arrays consist of GMR sensing strips of 1.5 μm or 0.75 μm in width. GMR sensors are exquisitely sensitive yet very delicate, requiring ultrathin corrosion-resistive passivation and efficient surface chemistry for oligonucleotide probe immobilization. A mild and stable surface chemistry was first developed that is especially suitable for modifying delicate electronic device surfaces, and a practical application of our GMR biosensors was then demonstrated for detecting four most common human papillomavirus (HPV) subtypes in plasmids. We also showed that the DNA hybridization time could potentially be reduced from overnight to about ten minutes using microfluidics.

Lithium-rich Giants in Globular Clusters

NASA Astrophysics Data System (ADS)

Kirby, Evan N.; Guhathakurta, Puragra; Zhang, Andrew J.; Hong, Jerry; Guo, Michelle; Guo, Rachel; Cohen, Judith G.; Cunha, Katia

2016-03-01

Although red giants deplete lithium on their surfaces, some giants are Li-rich. Intermediate-mass asymptotic giant branch (AGB) stars can generate Li through the Cameron-Fowler conveyor, but the existence of Li-rich, low-mass red giant branch (RGB) stars is puzzling. Globular clusters are the best sites to examine this phenomenon because it is straightforward to determine membership in the cluster and to identify the evolutionary state of each star. In 72 hours of Keck/DEIMOS exposures in 25 clusters, we found four Li-rich RGB and two Li-rich AGB stars. There were 1696 RGB and 125 AGB stars with measurements or upper limits consistent with normal abundances of Li. Hence, the frequency of Li-richness in globular clusters is (0.2 ± 0.1)% for the RGB, (1.6 ± 1.1)% for the AGB, and (0.3 ± 0.1)% for all giants. Because the Li-rich RGB stars are on the lower RGB, Li self-generation mechanisms proposed to occur at the luminosity function bump or He core flash cannot explain these four lower RGB stars. We propose the following origin for Li enrichment: (1) All luminous giants experience a brief phase of Li enrichment at the He core flash. (2) All post-RGB stars with binary companions on the lower RGB will engage in mass transfer. This scenario predicts that 0.1% of lower RGB stars will appear Li-rich due to mass transfer from a recently Li-enhanced companion. This frequency is at the lower end of our confidence interval. The data presented herein were 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.

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

Dispersal of Giant Molecular Clouds by Photoionization and Radiation Pressure

NASA Astrophysics Data System (ADS)

Kim, Jeong-Gyu; Kim, Woong-Tae; Ostriker, Eve C.

2018-01-01

UV radiation feedback from young massive stars plays a key role in the evolution of giant molecular clouds (GMCs) by forming HII regions and driving their expansion. We present the results of radiation hydrodynamic simulations of star cluster formation in turbulent GMCs, focusing on the effects of photoionization and radiation pressure on regulating the net star formation efficiency (SFE) and lifetime of clouds. We find that the net SFE depends primarily on the initial gas surface density, $\\Sigma_0$, such that the net SFE increases from 4% to 50% as $\\Sigma_0$ increases from $20\\,M_{\\odot}\\,{\\rm pc}^{-2}$ to $1300\\,M_{\\odot}\\,{\\rm pc}^{-2}$. Cloud dispersal occurs within $10\\,{\\rm Myr}$ after the onset of radiation feedback, or within 0.7--4.0 free-fall times that increases with $\\Sigma_0$. Photoionization plays a dominant role in destroying molecular clouds typical of the Milky Way, while radiation pressure takes over in massive, dense clouds. Based on the analysis of mass loss processes by photoevaporation or momentum injection, we develop a semi-analytic model for cloud dispersal and compare it with the numerical results.

Giant Spin Hall Effect and Switching Induced by Spin-Transfer Torque in a W /Co40Fe40B20/MgO Structure with Perpendicular Magnetic Anisotropy

NASA Astrophysics Data System (ADS)

Hao, Qiang; Xiao, Gang

2015-03-01

We obtain robust perpendicular magnetic anisotropy in a β -W /Co40Fe40B20/MgO structure without the need of any insertion layer between W and Co40Fe40B20 . This is achieved within a broad range of W thicknesses (3.0-9.0 nm), using a simple fabrication technique. We determine the spin Hall angle (0.40) and spin-diffusion length for the bulk β form of tungsten with a large spin-orbit coupling. As a result of the giant spin Hall effect in β -W and careful magnetic annealing, we significantly reduce the critical current density for the spin-transfer-torque-induced magnetic switching in Co40Fe40B20 . The elemental β -W is a superior candidate for magnetic memory and spin-logic applications.

Carbon content variation in boles of mature sugar maple and giant sequoia.

PubMed

Lamlom, Sabah H; Savidge, Rodney A

2006-04-01

At present, a carbon (C) content of 50% (w/w) in dry wood is widely accepted as a generic value; however, few wood C measurements have been reported. We used elemental analysis to investigate C content per unit of dry matter and observed that it varied both radially and vertically in boles of two old-growth tree species: sugar maple (Acer saccharum Marsh.) and giant sequoia (Sequoiadendron giganteum (Lindl.) Bucholz). In sugar maple there was considerable variation in tree ring widths among four radii for particular annual layers of xylem, revealing that the annual rate of C assimilation differs around the circumference and from the base of each tree to its top, but the observed variation in C content was unrelated to diameter growth rate and strongly related to the calendar year when the wood was formed. Carbon content in sugar maple wood increased in an approximately linear fashion, from < 50 to 51% from pith to cambium, at both the base and top of the boles. In giant sequoia, C was essentially constant at > 55% across many hundreds of years of heartwood, but it declined abruptly at the sapwood-heartwood boundary and remained lower in all sapwood samples, an indication that heartwood formation involves anabolic metabolism. Factors that may be responsible for the different C contents and trends with age between sugar maple and sequoia trees are considered. Tree-ring data from this study do not support some of the key assumptions made by dendrochronology.

Clustering the Orion B giant molecular cloud based on its molecular emission

NASA Astrophysics Data System (ADS)

Bron, Emeric; Daudon, Chloé; Pety, Jérôme; Levrier, François; Gerin, Maryvonne; Gratier, Pierre; Orkisz, Jan H.; Guzman, Viviana; Bardeau, Sébastien; Goicoechea, Javier R.; Liszt, Harvey; Öberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal

2018-02-01

Context. Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). Aims: We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. Methods: We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional probability density function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. Results: A clustering analysis based only on the J = 1-0 lines of three isotopologues of CO proves sufficient to reveal distinct density/column density regimes (nH 100 cm-3, 500 cm-3, and >1000 cm-3), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J = 1-0 line of HCO+ and the N = 1-0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO+ and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO+ intensity ratio in UV-illuminated regions. Finer distinctions in density classes (nH 7 × 103 cm-3, 4 × 104 cm-3) for the densest regions are also

Infrared dust bubble CS51 and its interaction with the surrounding interstellar medium

NASA Astrophysics Data System (ADS)

Das, Swagat R.; Tej, Anandmayee; Vig, Sarita; Liu, Hong-Li; Liu, Tie; Ishwara Chandra, C. H.; Ghosh, Swarna K.

2017-12-01

A multiwavelength investigation of the southern infrared dust bubble CS51 is presented in this paper. We probe the associated ionized, cold dust, molecular and stellar components. Radio continuum emission mapped at 610 and 1300 MHz, using the Giant Metrewave Radio Telescope, India, reveals the presence of three compact emission components (A, B, and C) apart from large-scale diffuse emission within the bubble interior. Radio spectral index map shows the co-existence of thermal and non-thermal emission components. Modified blackbody fits to the thermal dust emission using Herschel Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging Receiver data is performed to generate dust temperature and column density maps. We identify five dust clumps associated with CS51 with masses and radius in the range 810-4600 M⊙ and 1.0-1.9 pc, respectively. We further construct the column density probability distribution functions of the surrounding cold dust which display the impact of ionization feedback from high-mass stars. The estimated dynamical and fragmentation time-scales indicate the possibility of collect and collapse mechanism in play at the bubble border. Molecular line emission from the Millimeter Astronomy Legacy Team 90 GHz survey is used to understand the nature of two clumps which show signatures of expansion of CS51.

Footpoints of the giant molecular loops in the Galactic center region

NASA Astrophysics Data System (ADS)

Riquelme, D.; Amo-Baladrón, M. A.; Martín-Pintado, J.; Mauersberger, R.; Martín, S.; Burton, M.; Cunningham, M.; Jones, P. A.; Menten, K. M.; Bronfman, L.; Güsten, R.

2018-05-01

Aims: We aim to reveal the morphology, chemical composition, kinematics, and to establish the main processes prevalent in the gas at the footpoints of the giant molecular loops (GMLs) in the Galactic center region. Methods: Using the 22-m Mopra telescope, we mapped the M-3.8+0.9 molecular cloud, placed at the footpoints of a GML, in 3-mm range molecular lines. To derive the molecular hydrogen column density, we also observed the 13CO(2 - 1) line at 1 mm using the 12-m APEX telescope. From the 3 mm observations 12 molecular species were detected, namely HCO+, HCN, H13CN, HNC, SiO, CS, CH3OH, N2H+, SO, HNCO, OCS, and HC3N. Results: Maps revealing the morphology and kinematics of the M-3.8+0.9 molecular cloud in different molecules are presented. We identify six main molecular complexes. We derive fractional abundances in 11 selected positions of the different molecules assuming local thermodynamical equilibrium. Conclusions: Most of the fractional abundances derived for the M-3.8+0.9 molecular cloud are very similar over the whole cloud. However, the fractional abundances of some molecules show significant difference with respect to those measured in the central molecular zone (CMZ). The abundances of the shock tracer SiO are very similar between the GMLs and the CMZ. The methanol emission is the most abundant species in the GMLs. This indicates that the gas is likely affected by moderate 30 km s-1 or even high velocity (50 km s-1) shocks, consistent with the line profile observed toward one of the studied position. The origin of the shocks is likely related to the flow of the gas throughout the GMLs towards the footpoints. OPRA and APEX final data cubes (FITS) 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/A42

The giant molecular cloud Monoceros R2. 1: Shell structure

NASA Technical Reports Server (NTRS)

Xie, Taoling; Goldsmith, Paul F.

1994-01-01

We have obtained a 45 sec resolution, Nyquist-sampled map in CO J = 1-0 covering approximately a 3 deg x 3 deg region of the giant molecular cloud Monoceros R2. The map consists of 167,000 spectra observed with the 15 element focal-plane array system on the FCRAO 14 m telescope. The data reveal that the large-scale structure of Mon R2 is dominated by a is approximately 30 pc diameter largely hemispherical shell containing approximately 4 x 10(exp 4) solar mass of molecular material and expanding at approximately 3-4 km s(exp -1) with symmetric axis roughly along the line of sight. The dynamical timescale of the shell is estimated to be approximately 4 x 10(exp 6) yr, which is consistent with the age of main-sequence stars powering the clusters of reflection nebulea in this region. There is no evidence for a redshifted shell on the far side of the interior 'bubble,' which is largely devoid of molecular material. Distortions of the shell are obvious, suggesting inhomogeneity of the cloud and possible presence of a magnetic field prior to its formation. Dense clumps in Mon R2, including the main core and the GGD 12-15 core, appear to be condensations located on the large shell. The reflection nebulea with their illuminating stars as well as embedded IRAS sources suggest that triggered star formation has taken place over a large part of the Mon R2 shell.

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.

Detection of ethylene glycol - toward W51/e2 and G34.3+0.02

NASA Astrophysics Data System (ADS)

Lykke, Julie M.; Favre, Cécile

2014-07-01

Ethylene glycol (HOCH2CH2OH), also commenly known as antifreeze, is the reduced alcohol version of glycolaldehyde (CH2OHCHO). Glycoladehyde - the simplest possible aldehyde sugar (Marstokk and Møllendal 1973) - is the first intermediate step in the path toward forming more complex and biologically relevant molecules through the the formose reaction, which begins with formaldehyde (H2CO) and ends with the formation of sugars and ultimately ribose, the backbone of RNA (e.g., Larralde et al. 1995). The presence of glycolaldehyde is therefore an important indication that processes leading to biologically relevant molecules are taking place. It is however, still unclear as to how glycolaldehyde and ethylene glycol are formed in the ISM. It has been proposed that they share a common formation pathway through UV-irradiation of methanol (CH3OH) ices mixed with CO (Öberg et al. 2009). So far, ethylene glycol, in its lower energy con-former (g’Ga(CH2OH)2), has been detected toward SgrB2 (N) by Hollis et al. (2002), tentatively toward IRAS 16293-2422 (Jørgensen et al. 2012) and marginally by Kalenskii and Johansson (2010) toward W51 e1/e2. Here we present a firm detection of ethylene glycol toward W51/e2 as well as a first detection toward G34.3+0.02 at 1mm and 3mm using the IRAM 30m telescope.

Globally intertwined evolutionary history of giant barrel sponges

NASA Astrophysics Data System (ADS)

Swierts, Thomas; Peijnenburg, Katja T. C. A.; de Leeuw, Christiaan A.; Breeuwer, Johannes A. J.; Cleary, Daniel F. R.; de Voogd, Nicole J.

2017-09-01

Three species of giant barrel sponge are currently recognized in two distinct geographic regions, the tropical Atlantic and the Indo-Pacific. In this study, we used molecular techniques to study populations of giant barrel sponges across the globe and assessed whether the genetic structure of these populations agreed with current taxonomic consensus or, in contrast, whether there was evidence of cryptic species. Using molecular data, we assessed whether giant barrel sponges in each oceanic realm represented separate monophyletic lineages. Giant barrel sponges from 17 coral reef systems across the globe were sequenced for mitochondrial (partial CO1 and ATP6 genes) and nuclear (ATPsβ intron) DNA markers. In total, we obtained 395 combined sequences of the mitochondrial CO1 and ATP6 markers, which resulted in 17 different haplotypes. We compared a phylogenetic tree constructed from 285 alleles of the nuclear intron ATPsβ to the 17 mitochondrial haplotypes. Congruent patterns between mitochondrial and nuclear gene trees of giant barrel sponges provided evidence for the existence of multiple reproductively isolated species, particularly where they occurred in sympatry. The species complexes in the tropical Atlantic and the Indo-Pacific, however, do not form separate monophyletic lineages. This rules out the scenario that one species of giant barrel sponge developed into separate species complexes following geographic separation and instead suggests that multiple species of giant barrel sponges already existed prior to the physical separation of the Indo-Pacific and tropical Atlantic.

Quiescent Giant Molecular Cloud Cores in the Galactic Center

NASA Technical Reports Server (NTRS)

Lis, D. C.; Serabyn, E.; Zylka, R.; Li, Y.

2000-01-01

We have used the Long Wavelength Spectrometer (LWS) aboard the Infrared Space Observatory (ISO) to map the far-infrared continuum emission (45-175 micrometer) toward several massive Giant Molecular Cloud (GMC) cores located near the Galactic center. The observed far-infrared and submillimeter spectral energy distributions imply low temperatures (approx. 15 - 22 K) for the bulk of the dust in all the sources, consistent with external heating by the diffuse ISRF and suggest that these GMCs do not harbor high- mass star-formation sites, in spite of their large molecular mass. Observations of FIR atomic fine structure lines of C(sub II) and O(sub I) indicate an ISRF enhancement of approx. 10(exp 3) in the region. Through continuum radiative transfer modeling we show that this radiation field strength is in agreement with the observed FIR and submillimeter spectral energy distributions, assuming primarily external heating of the dust with only limited internal luminosity (approx. 2 x 10(exp 5) solar luminosity). Spectroscopic observations of millimeter-wave transitions of H2CO, CS, and C-34S carried out with the Caltech Submillimeter Observatory (CSO) and the Institut de Radio Astronomie Millimetrique (IRAM) 30-meter telescope indicate a gas temperature of approx. 80 K, significantly higher than the dust temperatures, and density of approx. 1 x 10(exp 5)/cc in GCM0.25 + 0.01, the brightest submillimeter source in the region. We suggest that shocks caused by cloud collisions in the turbulent interstellar medium in the Galactic center region are responsible for heating the molecular gas. This conclusion is supported by the presence of wide-spread emission from molecules such as SiO, SO, and CH3OH, which are considered good shock tracers. We also suggest that the GMCs studied here are representative of the "typical", pre-starforming cloud population in the Galactic center.

Tentative detection of ethylene glycol toward W51/e2 and G34.3+0.2 ⋆⋆⋆

NASA Astrophysics Data System (ADS)

Lykke, J. M.; Favre, C.; Bergin, E. A.; Jørgensen, J. K.

2015-10-01

Context. With only a few low- and high-mass star-formation regions studied in detail so far, it is unclear what role the enviroment plays in complex molecule formation. In this light, a comparison of relative abundances of related species between sources might be useful for explaining any observed differences. Aims: We seek to measure the relative abundance between three important complex organic molecules, ethylene glycol ((CH2OH)2), glycolaldehyde (CH2OHCHO) and methyl formate (HCOOCH3), toward high-mass protostars and thereby provide additional constraints on their formation pathways. Methods: We use IRAM 30 m single-dish observations of the three species toward two high-mass star-forming regions - W51/e2 and G34.3+0.2 - and report a tentative detection of (CH2OH)2 toward both sources. Results: Assuming that (CH2OH)2, CH2OHCHO, and HCOOCH3 spatially coexist, relative abundance ratios, HCOOCH3/(CH2OH)2, of 31 and 35 are derived for G34.3+0.2 and W51/e2, respectively. CH2OHCHO is not detected, but the data provide lower limits to the HCOOCH3/CH2OHCHO abundance ratios of ≥193 for G34.3+0.2 and ≥550 for W51/e2. A comparison of these results to measurements from various sources in the literature indicates that the source luminosities may be correlated with the HCOOCH3/(CH2OH)2 and HCOOCH3/CH2OHCHO ratios. This apparent correlation may be a consequence of the relative time scales each source spend at different temperature ranges in their evolution. Furthermore, we obtain lower limits to the ratio of (CH2OH)2/CH2OHCHO for G34.3+0.2 (≥6) and W51/e2 (≥16). This result confirms that a high (CH2OH)2/CH2OHCHO abundance ratio is not a specific property of comets, as previously speculated. Based on observations carried out with the IRAM 30 m telescope.The reduced spectra (FITS files) are 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/582/A64Appendices are available in

Quasar feedback revealed by giant molecular outflows

NASA Astrophysics Data System (ADS)

Feruglio, C.; Maiolino, R.; Piconcelli, E.; Menci, N.; Aussel, H.; Lamastra, A.; Fiore, F.

2010-07-01

In the standard scenario for galaxy evolution young star-forming galaxies transform into red bulge-dominated spheroids, where star formation has been quenched. To explain this transformation, a strong negative feedback generated by accretion onto a central super-massive black hole is often invoked. The depletion of gas resulting from quasar-driven outflows should eventually stop star-formation across the host galaxy and lead the black hole to “suicide” by starvation. Direct observational evidence for a major quasar feedback onto the host galaxy is still missing, because outflows previously observed in quasars are generally associated with the ionized component of the gas, which only accounts for a minor fraction of the total gas content, and typically occurrs in the central regions. We used the IRAM PdB Interferometer to observe the CO(1-0) transition in Mrk 231, the closest quasar known. Thanks to the wide band we detected broad wings of the CO line, with velocities of up to 750 km s-1 and spatially resolved on the kpc scale. These broad CO wings trace a giant molecular outflow of about 700 M_⊙/year, far larger than the ongoing star-formation rate (~200 M_⊙/year) observed in the host galaxy. This wind will totally expel the cold gas reservoir in Mrk 231 in about 107 yrs, therefore halting the star-formation activity on the same timescale. The inferred kinetic energy in the molecular outflow is ~1.2 × 1044 erg/s, corresponding to a few percent of the AGN bolometric luminosity, which is very close to the fraction expected by models ascribing quasar feedback to highly supersonic shocks generated by radiatively accelerated nuclear winds. Instead, the contribution by the SNe associated with the starburst fall short by several orders of magnitude to account for the kinetic energy observed in the outflow. The direct observational evidence for quasar feedback reported here provides solid support to the scenarios ascribing the observed properties of local massive

Molecular Line and Continuum Opacities for Modeling of Extrasolar Giant Planet and Cool Stellar Atmospheres

NASA Technical Reports Server (NTRS)

Weck, P. F.; Schweitzer, A.; Stancil, P. C.; Hauschildt, P. H.; Kirby, K.; Yamaguchi, Y.; Allen, W. D.

2002-01-01

The molecular line and continuum opacities are investigated in the atmospheres of cool stars and Extrasolar Giant Planets (EGPs). Using a combination of ab inito and experimentally derived potential curves and dipole transition moments, accurate data have been calculated for rovibrationally-resolved oscillator strengths and photodissociation cross sections in the B' (sup 2)Sigma+ (left arrow) X (sup 2)Sigma+ and A (sup 2)Pi (left arrow) X (sup 2)Sigma+ band systems in MgH. We also report our progress on the study of the electronic structure of LiCl and FeH.

50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Modified Gear Trawl Zone 51 Table 51 to..., Table 51 Table 51 to Part 679—Modified Gear Trawl Zone Longitude Latitude 171 45.00 W 61 00.00 N 169 00.00 W 61 00.00 N 169 00.00 W 60 35.48 N 171 45.00 W 60 06.15 N Note: The area is delineated by...

50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Modified Gear Trawl Zone 51 Table 51 to..., Table 51 Table 51 to Part 679—Modified Gear Trawl Zone Longitude Latitude 171 45.00 W 61 00.00 N 169 00.00 W 61 00.00 N 169 00.00 W 60 35.48 N 171 45.00 W 60 06.15 N Note: The area is delineated by...

50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Modified Gear Trawl Zone 51 Table 51 to..., Table 51 Table 51 to Part 679—Modified Gear Trawl Zone Longitude Latitude 171 45.00 W 61 00.00 N 169 00.00 W 61 00.00 N 169 00.00 W 60 35.48 N 171 45.00 W 60 06.15 N Note: The area is delineated by...

50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Modified Gear Trawl Zone 51 Table 51 to..., Table 51 Table 51 to Part 679—Modified Gear Trawl Zone Longitude Latitude 171 45.00 W 61 00.00 N 169 00.00 W 61 00.00 N 169 00.00 W 60 35.48 N 171 45.00 W 60 06.15 N Note: The area is delineated by...

Giant molecular cloud scaling relations: the role of the cloud definition

NASA Astrophysics Data System (ADS)

Khoperskov, S. A.; Vasiliev, E. O.; Ladeyschikov, D. A.; Sobolev, A. M.; Khoperskov, A. V.

2016-01-01

We investigate the physical properties of molecular clouds in disc galaxies with different morphologies: a galaxy without prominent structure, a spiral barred galaxy and a galaxy with flocculent structure. Our N-body/hydrodynamical simulations take into account non-equilibrium H2 and CO chemical kinetics, self-gravity, star formation and feedback processes. For the simulated galaxies, the scaling relations of giant molecular clouds, or so-called Larson's relations, are studied for two types of cloud definition (or extraction method): the first is based on total column density position-position (PP) data sets and the second is indicated by the CO (1-0) line emission used in position-position-velocity (PPV) data. We find that the cloud populations obtained using both cloud extraction methods generally have similar physical parameters, except that for the CO data the mass spectrum of clouds has a tail with low-mass objects M ˜ 103-104 M⊙. Owing toa varying column density threshold, the power-law indices in the scaling relations are significantly changed. In contrast, the relations are invariant to the CO brightness temperature threshold. Finally, we find that the mass spectra of clouds for PPV data are almost insensitive to the galactic morphology, whereas the spectra for PP data demonstrate significant variation.

Spectroscopy of Six Red Giants in the Draco Dwarf Spheroidal Galaxy

NASA Astrophysics Data System (ADS)

Smith, Graeme H.; Siegel, Michael H.; Shetrone, Matthew D.; Winnick, Rebeccah

2006-10-01

Keck Observatory LRIS-B (Low Resolution Imaging Spectrometer) spectra are reported for six red giant stars in the Draco dwarf spheroidal galaxy and several comparison giants in the globular cluster M13. Indexes that quantify the strengths of the Ca II H and K lines, the λ3883 and λ4215 CN bands, and the λ4300 G band have been measured. These data confirm evidence of metallicity inhomogeneity within Draco obtained by previous authors. The four brightest giants in the sample have absolute magnitudes in the range -2.6giants and that some giants have higher [C/Fe] ratios than is typical of giants in the globular clusters M13 and M92. Several suggestions are made as to why some Draco stars may have higher [C/Fe] ratios than globular cluster red giants: deep mixing might be inhibited in these Draco stars, they may formerly have been mass-transfer binaries that acquired carbon from a more massive companion, or the Draco dwarf galaxy may have experienced relatively slow chemical evolution over a period of several billion years, allowing carbon-enhanced ejecta from intermediate-mass asymptotic giant branch stars to enrich the interstellar medium while star formation was still occurring. The data presented herein were 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.

wFReDoW: A Cloud-Based Web Environment to Handle Molecular Docking Simulations of a Fully Flexible Receptor Model

PubMed Central

De Paris, Renata; Frantz, Fábio A.; Norberto de Souza, Osmar; Ruiz, Duncan D. A.

2013-01-01

Molecular docking simulations of fully flexible protein receptor (FFR) models are coming of age. In our studies, an FFR model is represented by a series of different conformations derived from a molecular dynamic simulation trajectory of the receptor. For each conformation in the FFR model, a docking simulation is executed and analyzed. An important challenge is to perform virtual screening of millions of ligands using an FFR model in a sequential mode since it can become computationally very demanding. In this paper, we propose a cloud-based web environment, called web Flexible Receptor Docking Workflow (wFReDoW), which reduces the CPU time in the molecular docking simulations of FFR models to small molecules. It is based on the new workflow data pattern called self-adaptive multiple instances (P-SaMIs) and on a middleware built on Amazon EC2 instances. P-SaMI reduces the number of molecular docking simulations while the middleware speeds up the docking experiments using a High Performance Computing (HPC) environment on the cloud. The experimental results show a reduction in the total elapsed time of docking experiments and the quality of the new reduced receptor models produced by discarding the nonpromising conformations from an FFR model ruled by the P-SaMI data pattern. PMID:23691504

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.

Giant molecular cloud collisions as triggers of star formation. VI. Collision-induced turbulence

NASA Astrophysics Data System (ADS)

Wu, Benjamin; Tan, Jonathan C.; Nakamura, Fumitaka; Christie, Duncan; Li, Qi

2018-05-01

We investigate collisions between giant molecular clouds (GMCs) as potential generators of their internal turbulence. Using magnetohydrodynamic (MHD) simulations of self-gravitating, magnetized, turbulent GMCs, we compare kinematic and dynamic properties of dense gas structures formed when such clouds collide compared to those that form in non-colliding clouds as self-gravity overwhelms decaying turbulence. We explore the nature of turbulence in these structures via distribution functions of density, velocity dispersions, virial parameters, and momentum injection. We find that the dense clumps formed from GMC collisions have higher effective Mach number, greater overall velocity dispersions, sustain near-virial equilibrium states for longer times, and are the conduit for the injection of turbulent momentum into high density gas at high rates.

Giant molecular cloud collisions as triggers of star formation. VI. Collision-induced turbulence

NASA Astrophysics Data System (ADS)

Wu, Benjamin; Tan, Jonathan C.; Nakamura, Fumitaka; Christie, Duncan; Li, Qi

2018-01-01

We investigate collisions between giant molecular clouds (GMCs) as potential generators of their internal turbulence. Using magnetohydrodynamic (MHD) simulations of self-gravitating, magnetized, turbulent GMCs, we compare kinematic and dynamic properties of dense gas structures formed when such clouds collide compared to those that form in non-colliding clouds as self-gravity overwhelms decaying turbulence. We explore the nature of turbulence in these structures via distribution functions of density, velocity dispersions, virial parameters, and momentum injection. We find that the dense clumps formed from GMC collisions have higher effective Mach number, greater overall velocity dispersions, sustain near-virial equilibrium states for longer times, and are the conduit for the injection of turbulent momentum into high density gas at high rates.

Structure and extent of the giant molecular cloud near M17

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

Elmegreen, B.G.; Lada, C.J.; Dickinson, D.F.

1979-06-01

Carbon monoxide emission at ..nu../sub LSR/ = 20 +- 2 km s/sup -1/ is found to extend 4/sup 0/ (approx.170 pc) southwest of M17, and is studied in an attempt to understand the internal structure and dynamics of a giant molecular cloud complex. The region contains two primary clouds. The first has at least 2 x 10/sup 5/ M/sub sun/ of molecular gas and extends for 1./sup 0/8 (72 pc) parallel to, but below the galactic plane southwest of M17. The second, located above the plane approximately 2./sup 0/5 southwest of M17, is about 1./sup 0/7 in extent, but containsmore » considerably less molecular mass (> or approx. =3 x 10/sup 4/ M/sub sun/). Between these two clouds is a 1/sup 0/ long region of relatively low intensity, clumpy CO emission which appears to bridge the two main clouds. The molecular mass within this bridge is estimated to be 2 x 10/sup 4/ M/sub sun/. The cloud associated with M17 is itself divided into four discrete fragments of approximately equal mass (4 x 10/sup 4/ M/sub sun/). The /sup 12/CO and /sup 13/CO line widths are higher in these four fragments than they are between the fragments. OB star formation is active only in the northeastern two of these fragments. The /sup 13/CO line widths in the discrete fragments satisfy the virial theorem for the derived masses. (b) The /sup 13/CO velocity structure in the large complex containing M17 shows a gradual change from regularity in the northeast to irregularity and occasionally multipeaked profiles in the southwest. This change corresponds to a gradient in the degree of compactness and intensity of star formation in the four fragments. A massive (10/sup 5/ M/sub sun/) molecular cloud complex associated with M16, 2/sup 0/ north of M17, and the two clouds southwest of M17, form a pattern of equally spaced star-forming clouds whose positions alternate above and below the galactic plane. Patchy CO emission is found between these three objects. The entire region of molecular emission is approx.250 pc

Molecular phylogeny and taxonomic revision of the genus Wittrockiella (Pithophoraceae, Cladophorales), including the descriptions of W. australis sp. nov. and W. zosterae sp. nov.

PubMed

Boedeker, Christian; O'Kelly, Charles J; West, John A; Hanyuda, Takeaki; Neale, Adele; Wakana, Isamu; Wilcox, Mike D; Karsten, Ulf; Zuccarello, Giuseppe C

2017-06-01

Wittrockiella is a small genus of filamentous green algae that occurs in habitats with reduced or fluctuating salinities. Many aspects of the basic biology of these algae are still unknown and the phylogenetic relationships within the genus have not been fully explored. We provide a phylogeny based on three ribosomal markers (ITS, LSU, and SSU rDNA) of the genus, including broad intraspecific sampling for W. lyallii and W. salina, recommendations for the use of existing names are made, and highlight aspects of their physiology and life cycle. Molecular data indicate that there are five species of Wittrockiella. Two new species, W. australis and W. zosterae, are described, both are endophytes. Although W. lyallii and W. salina can be identified morphologically, there are no diagnostic morphological characters to distinguish between W. amphibia, W. australis, and W. zosterae. A range of low molecular weight carbohydrates were analyzed but proved to not be taxonomically informative. The distribution range of W. salina is extended to the Northern Hemisphere as this species has been found in brackish lakes in Japan. Furthermore, it is shown that there are no grounds to recognize W. salina var. kraftii, which was described as an endemic variety from a freshwater habitat on Lord Howe Island, Australia. Culture experiments indicate that W. australis has a preference for growth in lower salinities over full seawater. For W. amphibia and W. zosterae, sexual reproduction is documented, and the split of these species is possibly attributable to polyploidization. © 2017 Phycological Society of America.

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

ULTRAVIOLET ESCAPE FRACTIONS FROM GIANT MOLECULAR CLOUDS DURING EARLY CLUSTER FORMATION

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

Howard, Corey; Pudritz, Ralph; Klessen, Ralf

2017-01-01

The UV photon escape fraction from molecular clouds is a key parameter for understanding the ionization of the interstellar medium and extragalactic processes such as cosmic reionization. We present the ionizing photon flux and the corresponding photon escape fraction ( f {sub esc}) arising as a consequence of star cluster formation in a turbulent, 10{sup 6} M {sub ⊙} giant molecular cloud, simulated using the code FLASH. We make use of sink particles to represent young, star-forming clusters coupled with a radiative transfer scheme to calculate the emergent UV flux. We find that the ionizing photon flux across the cloudmore » boundary is highly variable in time and space due to the turbulent nature of the intervening gas. The escaping photon fraction remains at ∼5% for the first 2.5 Myr, followed by two pronounced peaks at 3.25 and 3.8 Myr with a maximum f {sub esc} of 30% and 37%, respectively. These peaks are due to the formation of large H ii regions that expand into regions of lower density, some of which reaching the cloud surface. However, these phases are short-lived, and f {sub esc} drops sharply as the H ii regions are quenched by the central cluster passing through high-density material due to the turbulent nature of the cloud. We find an average f {sub esc} of 15% with factor of two variations over 1 Myr timescales. Our results suggest that assuming a single value for f {sub esc} from a molecular cloud is in general a poor approximation, and that the dynamical evolution of the system leads to large temporal variation.« less

Mapping of the extinction in giant molecular clouds using optical star counts

NASA Astrophysics Data System (ADS)

Cambrésy, L.

1999-05-01

This paper presents large scale extinction maps of most nearby Giant Molecular Clouds of the Galaxy (Lupus, rho Ophiuchus, Scorpius, Coalsack, Taurus, Chamaeleon, Musca, Corona Australis, Serpens, IC 5146, Vela, Orion, Monoceros R1 and R2, Rosette, Carina) derived from a star count method using an adaptive grid and a wavelet decomposition applied to the optical data provided by the USNO-Precision Measuring Machine. The distribution of the extinction in the clouds leads to estimate their total individual masses M and their maximum of extinction. I show that the relation between the mass contained within an iso-extinction contour and the extinction is similar from cloud to cloud and allows the extrapolation of the maximum of extinction in the range 5.7 to 25.5 magnitudes. I found that about half of the mass is contained in regions where the visual extinction is smaller than 1 magnitude. The star count method used on large scale ( ~ 250 square degrees) is a powerful and relatively straightforward method to estimate the mass of molecular complexes. A systematic study of the all sky would lead to discover new clouds as I did in the Lupus complex for which I found a sixth cloud of about 10(4) M_⊙.

Chemical evolution of giant molecular clouds in simulations of galaxies

NASA Astrophysics Data System (ADS)

Richings, Alexander J.; Schaye, Joop

2016-08-01

We present an analysis of giant molecular clouds (GMCs) within hydrodynamic simulations of isolated, low-mass (M* ˜ 109 M⊙) disc galaxies. We study the evolution of molecular abundances and the implications for CO emission and the XCO conversion factor in individual clouds. We define clouds either as regions above a density threshold n_{H, min} = 10 {cm}^{-3}, or using an observationally motivated CO intensity threshold of 0.25 {K} {km} {s}^{-1}. Our simulations include a non-equilibrium chemical model with 157 species, including 20 molecules. We also investigate the effects of resolution and pressure floors (I.e. Jeans limiters). We find cloud lifetimes up to ≈ 40 Myr, with a median of 13 Myr, in agreement with observations. At one-tenth solar metallicity, young clouds ( ≲ 10-15 Myr) are underabundant in H2 and CO compared to chemical equilibrium, by factors of ≈3 and one to two orders of magnitude, respectively. At solar metallicity, GMCs reach chemical equilibrium faster (within ≈ 1 Myr). We also compute CO emission from individual clouds. The mean CO intensity, ICO, is strongly suppressed at low dust extinction, Av, and possibly saturates towards high Av, in agreement with observations. The ICO-Av relation shifts towards higher Av for higher metallicities and, to a lesser extent, for stronger UV radiation. At one-tenth solar metallicity, CO emission is weaker in young clouds ( ≲ 10-15 Myr), consistent with the underabundance of CO. Consequently, XCO decreases by an order of magnitude from 0 to 15 Myr, albeit with a large scatter.

Polarization Properties and Magnetic Field Structures in the High-mass Star-forming Region W51 Observed with ALMA

NASA Astrophysics Data System (ADS)

Koch, Patrick M.; Tang, Ya-Wen; Ho, Paul T. P.; Yen, Hsi-Wei; Su, Yu-Nung; Takakuwa, Shigehisa

2018-03-01

We present the first ALMA dust polarization observations toward the high-mass star-forming regions W51 e2, e8, and W51 North in Band 6 (230 GHz) with a resolution of about 0\\buildrel{\\prime\\prime}\\over{.} 26 (∼5 mpc). Polarized emission in all three sources is clearly detected and resolved. Measured relative polarization levels are between 0.1% and 10%. While the absolute polarization shows complicated structures, the relative polarization displays the typical anticorrelation with Stokes I, although with a large scatter. Inferred magnetic (B) field morphologies are organized and connected. Detailed substructures are resolved, revealing new features such as comet-shaped B-field morphologies in satellite cores, symmetrically converging B-field zones, and possibly streamlined morphologies. The local B-field dispersion shows some anticorrelation with the relative polarization. Moreover, the lowest polarization percentages together with largest dispersions coincide with B-field convergence zones. We put forward \\sin ω , where ω is the measurable angle between a local B-field orientation and local gravity, as a measure of how effectively the B field can oppose gravity. Maps of \\sin ω for all three sources show organized structures that suggest a locally varying role of the B field, with some regions where gravity can largely act unaffectedly, possibly in a network of narrow magnetic channels, and other regions where the B field can work maximally against gravity.

Dilute oxalic acid pretreatment for biorefining giant reed (Arundo donax L.)

Treesearch

Danilo Scordia; Salvatore L. Cosentino; Jae-Won Lee; Thomas W. Jeffries

2011-01-01

Biomass pretreatment is essential to overcome recalcitrance of lignocellulose for ethanol production. In the present study we pretreated giant reed (Arundo donax L.), a perennial, rhizomatous lignocellulosic grass with dilute oxalic acid. The effects of temperature (170-190 ºC), acid loading (2-10% w/w) and reaction time (15-40 min) were handled as a single...

Molecular cloning and characterization of human trabeculin-alpha, a giant protein defining a new family of actin-binding proteins.

PubMed

Sun, Y; Zhang, J; Kraeft, S K; Auclair, D; Chang, M S; Liu, Y; Sutherland, R; Salgia, R; Griffin, J D; Ferland, L H; Chen, L B

1999-11-19

We describe the molecular cloning and characterization of a novel giant human cytoplasmic protein, trabeculin-alpha (M(r) = 614,000). Analysis of the deduced amino acid sequence reveals homologies with several putative functional domains, including a pair of alpha-actinin-like actin binding domains; regions of homology to plakins at either end of the giant polypeptide; 29 copies of a spectrin-like motif in the central region of the protein; two potential Ca(2+)-binding EF-hand motifs; and a Ser-rich region containing a repeated GSRX motif. With similarities to both plakins and spectrins, trabeculin-alpha appears to have evolved as a hybrid of these two families of proteins. The functionality of the actin binding domains located near the N terminus was confirmed with an F-actin binding assay using glutathione S-transferase fusion proteins comprising amino acids 9-486 of the deduced peptide. Northern and Western blotting and immunofluorescence studies suggest that trabeculin is ubiquitously expressed and is distributed throughout the cytoplasm, though the protein was found to be greatly up-regulated upon differentiation of myoblasts into myotubes. Finally, the presence of cDNAs similar to, yet distinct from, trabeculin-alpha in both human and mouse suggests that trabeculins may form a new subfamily of giant actin-binding/cytoskeletal cross-linking proteins.

Dust and molecular shells in asymptotic giant branch stars

NASA Astrophysics Data System (ADS)

Zhao-Geisler, R.; Quirrenbach, A.; Köhler, R.; Lopez, B.

2012-09-01

Context. Asymptotic giant branch (AGB) stars are one of the largest distributors of dust into the interstellar medium. However, the wind formation mechanism and dust condensation sequence leading to the observed high mass-loss rates have not yet been constrained well observationally, in particular for oxygen-rich AGB stars. Aims: The immediate objective in this work is to identify molecules and dust species which are present in the layers above the photosphere, and which have emission and absorption features in the mid-infrared (IR), causing the diameter to vary across the N-band, and are potentially relevant for the wind formation. Methods: Mid-IR (8-13 μm) interferometric data of four oxygen-rich AGB stars (R Aql, R Aqr, R Hya, and W Hya) and one carbon-rich AGB star (V Hya) were obtained with MIDI/VLTI between April 2007 and September 2009. The spectrally dispersed visibility data are analyzed by fitting a circular fully limb-darkened disk (FDD). Results: The FDD diameter as function of wavelength is similar for all oxygen-rich stars. The apparent size is almost constant between 8 and 10 μm and gradually increases at wavelengths longer than 10 μm. The apparent FDD diameter in the carbon-rich star V Hya essentially decreases from 8 to 12 μm. The FDD diameters are about 2.2 times larger than the photospheric diameters estimated from K-band observations found in the literature. The silicate dust shells of R Aql, R Hya and W Hya are located fairly far away from the star, while the silicate dust shell of R Aqr and the amorphous carbon (AMC) and SiC dust shell of V Hya are found to be closer to the star at around 8 photospheric radii. Phase-to-phase variations of the diameters of the oxygen-rich stars could be measured and are on the order of 15% but with large uncertainties. Conclusions: From a comparison of the diameter trend with the trends in RR Sco and S Ori it can be concluded that in oxygen-rich stars the overall larger diameter originates from a warm

Tungsten isotope evidence for post-giant impact equilibration of the Earth and Moon

NASA Astrophysics Data System (ADS)

Kruijer, T.; Kleine, T.; Fischer-Gödde, M.

2015-12-01

The Moon is thought to have formed by re-accretion of material ejected by a giant impact on Earth [e.g., 1]. This model, at least in its classical form, predicts an isotopic difference between the Earth and Moon, because the Moon would largely consist of impactor material. Yet Earth and Moon show an unexpected isotopic similarity for many elements [e.g., 2]. Here we use variations in 182W—the decay-product of short-lived 182Hf (t1/2~9 Myr)—between the Moon and the bulk silicate Earth (BSE) to shed new light on this issue. We precisely determined the lunar 182W value by analysing KREEP-rich samples with MC-ICPMS and a new approach for quantifying cosmogenic 182W variations using Hf isotopes [6]. We find that the Moon shows a 27±4 ppm 182W excess over the modern BSE, in excellent agreement with [7]. This excess agrees with the predicted 182W change resulting from disproportional late accretion to the Earth and Moon after Earth's core had fully formed [6,7]. Thus, the pre-late-veneer BSE and the Moon were indistinguishable in 182W. However, the giant impact itself should have caused a notable Earth-Moon 182W difference by (1) changing the ɛ182W of the proto-Earth mantle by adding impactor mantle and core material, both carrying distinct 182W anomalies, and (2) by supplying W-rich but 182W-depleted impactor core material into the lunar accretion disk [6]. Thus, the Earth-Moon 182W homogeneity is an unexpected outcome of the giant impact. Unlike for Ti and O isotopes, the 182W homogeneity cannot be explained by accretion of impactor and proto-Earth from a homogeneous inner disk reservoir [3] or by making the Moon fully from proto-Earth mantle [4,5]. Thus, the 182W results require an efficient post-impact isotopic equilibration of the BSE and the Moon, but the mechanism for this has yet to be explored. One option is that Earth's mantle and its vapour atmosphere remained connected with the lunar accretion disk just after the giant impact [8]. [1] Canup R

Using Velocity Anisotropy to Analyze Magnetohydrodynamic Turbulence in Giant Molecular Clouds

NASA Astrophysics Data System (ADS)

Madrid, Alecio; Hernandez, Audra

2018-01-01

Structure function (SF) analysis is a strong tool for gaging the Alfvénic properties of magnetohydrodynamic (MHD) simulations, yet there is a lack of literature rigorously investigating limitations in the context of radio spectroscopy. This study takes an in depth approach to studying the limitations of SF analysis for analyzing MHD turbulence in giant molecular cloud (GMC) spectroscopy data. MHD turbulence plays a critical role in the structure and evolution of GMCs as well as in the formation of sub-structures known to spawn stellar progenitors. Existing methods of detection are neither economical nor robust (e.g. dust polarization), and nowhere is this more clear than in the theoretical-observational divide in current literature. A significant limitation of GMC spectroscopy results from the large variation in methods used for extracting GMCs from survey data. Thus, a robust method for studying MHD turbulence must correctly gauge physical properties regardless of the data extraction method used. While SF analysis has demonstrated strong potential across a range of simulated conditions, this study finds significant concern regarding its feasibility as a robust tool in GMC spectroscopy.

STS-51F crew activities

NASA Image and Video Library

2009-06-25

51F-06-017 (29 July-6 Aug. 1985) --- Crew portrait with sunglasses. C. Gordon Fullerton's head is at center. Others (bottom, l.-r.) are Roy D. Bridges, F. Story Musgrave and John David Bartoe; and (top) Karl J. Henize, Loren W. Acton and Anthony W. England.

Evolutionary Description of Giant Molecular Cloud Mass Functions on Galactic Disks

NASA Astrophysics Data System (ADS)

Kobayashi, Masato I. N.; Inutsuka, Shu-ichiro; Kobayashi, Hiroshi; Hasegawa, Kenji

2017-02-01

Recent radio observations show that giant molecular cloud (GMC) mass functions noticeably vary across galactic disks. High-resolution magnetohydrodynamics simulations show that multiple episodes of compression are required for creating a molecular cloud in the magnetized interstellar medium. In this article, we formulate the evolution equation for the GMC mass function to reproduce the observed profiles, for which multiple compressions are driven by a network of expanding shells due to H II regions and supernova remnants. We introduce the cloud-cloud collision (CCC) terms in the evolution equation in contrast to previous work (Inutsuka et al.). The computed time evolution suggests that the GMC mass function slope is governed by the ratio of GMC formation timescale to its dispersal timescale, and that the CCC effect is limited only in the massive end of the mass function. In addition, we identify a gas resurrection channel that allows the gas dispersed by massive stars to regenerate GMC populations or to accrete onto pre-existing GMCs. Our results show that almost all of the dispersed gas contributes to the mass growth of pre-existing GMCs in arm regions whereas less than 60% contributes in inter-arm regions. Our results also predict that GMC mass functions have a single power-law exponent in the mass range <105.5 {M}⊙ (where {M}⊙ represents the solar mass), which is well characterized by GMC self-growth and dispersal timescales. Measurement of the GMC mass function slope provides a powerful method to constrain those GMC timescales and the gas resurrecting factor in various environments across galactic disks.

A study of spin isovector giant resonances with the208Pb(n, p)208Tl reaction

NASA Astrophysics Data System (ADS)

Moinester, M. A.; Trudel, A.; Raywood, K.; Yen, S.; Spicer, B. M.; Abegg, R.; Alford, W. P.; Auerbach, N.; Celler, A.; Frekers, D.; Häusser, O.; Helmer, R. L.; Henderson, R.; Hicks, K. H.; Jackson, K. P.; Jeppesen, R. G.; King, N. S. P.; Long, S.; Miller, C. A.; Vetterli, M.; Watson, J.; Yavin, A. I.

1989-10-01

The208Pb(n, p)208Tl reaction was studied at 198 and 458 MeV in a search for isovector spin giant resonances. Peaks at 5.1 MeV and 13.6 MeV excitation in208Tl are observed and discussed as candidates for the T> spin giant dipole resonance (SGDR), the spin isovector monopole resonance (SIVM), and the spin isovector quadrupole resonance (SIVQ).

Giant photoluminescence emission in crystalline faceted Si grains

PubMed Central

Faraci, Giuseppe; Pennisi, Agata R.; Alberti, Alessandra; Ruggeri, Rosa; Mannino, Giovanni

2013-01-01

Empowering an indirect band-gap material like Si with optical functionalities, firstly light emission, represents a huge advancement constantly pursued in the realization of any integrated photonic device. We report the demonstration of giant photoluminescence (PL) emission by a newly synthesized material consisting of crystalline faceted Si grains (fg-Si), a hundred nanometer in size, assembled in a porous and columnar configuration, without any post processing. A laser beam with wavelength 632.8 nm locally produce such a high temperature, determined on layers of a given thickness by Raman spectra, to induce giant PL radiation emission. The optical gain reaches the highest value ever, 0.14 cm/W, representing an increase of 3 orders of magnitude with respect to comparable data recently obtained in nanocrystals. Giant emission has been obtained from fg-Si deposited either on glass or on flexible, low cost, polymeric substrate opening the possibility to fabricate new devices. PMID:24056300

Modeling UV Radiation Feedback from Massive Stars. II. Dispersal of Star-forming Giant Molecular Clouds by Photoionization and Radiation Pressure

NASA Astrophysics Data System (ADS)

Kim, Jeong-Gyu; Kim, Woong-Tae; Ostriker, Eve C.

2018-05-01

UV radiation feedback from young massive stars plays a key role in the evolution of giant molecular clouds (GMCs) by photoevaporating and ejecting the surrounding gas. We conduct a suite of radiation hydrodynamic simulations of star cluster formation in marginally bound, turbulent GMCs, focusing on the effects of photoionization and radiation pressure on regulating the net star formation efficiency (SFE) and cloud lifetime. We find that the net SFE depends primarily on the initial gas surface density, Σ0, such that the SFE increases from 4% to 51% as Σ0 increases from 13 to 1300 {M}ȯ {pc}}-2. Cloud destruction occurs within 2–10 Myr after the onset of radiation feedback, or within 0.6–4.1 freefall times (increasing with Σ0). Photoevaporation dominates the mass loss in massive, low surface density clouds, but because most photons are absorbed in an ionization-bounded Strömgren volume, the photoevaporated gas fraction is proportional to the square root of the SFE. The measured momentum injection due to thermal and radiation pressure forces is proportional to {{{Σ }}}0-0.74, and the ejection of neutrals substantially contributes to the disruption of low mass and/or high surface density clouds. We present semi-analytic models for cloud dispersal mediated by photoevaporation and by dynamical mass ejection, and show that the predicted net SFE and mass loss efficiencies are consistent with the results of our numerical simulations.

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

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.

Isoscalar giant monopole resonance in Sn isotopes using a quantum molecular dynamics model

NASA Astrophysics Data System (ADS)

Tao, C.; Ma, Y. G.; Zhang, G. Q.; Cao, X. G.; Fang, D. Q.; Wang, H. W.; Xu, J.

2013-12-01

The isoscalar giant monopole resonance (GMR) in Sn isotopes and other nuclei is investigated in the framework of the isospin-dependent quantum molecular dynamics (IQMD) model. The spectrum of GMR is calculated by taking the rms radius of a nucleus as its monopole moment. The peak energy, the FWHM, and the strength of the GMR extracted by a Gaussian fit to the spectrum have been studied. The GMR peak energies for Sn isotopes from the calculations using a mass-number-dependent Gaussian wave-packet width σr for nucleons are found to be overestimated and show a weak dependence on the mass number compared with the experimental data. However, it is found that experimental data of the GMR peak energies for 56Ni, 90Zr, and 208Pb as well as Sn isotopes can be nicely reproduced after taking into account the isospin dependence in isotope chains in addition to the mass-number dependence of σr for nucleons in the IQMD model calculation.

Molecular dynamics simulations and principal component analysis on human laforin mutation W32G and W32G/K87A.

PubMed

Srikumar, P S; Rohini, K; Rajesh, Perumbilavil Kaithamanakallam

2014-06-01

Mutations in human laforin lead to an autosomal neurodegenerative disorder Lafora disease. In N-terminal carbohydrate binding domain of laforin, two mutations W32G and K87A are reported as highly disease causing laforin mutants. Experimental studies reported that mutations are responsible for the abolishment of glycogen binding which is a critical function of laforin. Our current computational study focused on the role of conformational changes in human laforin structure due to existing single mutation W32G and prepared double mutation W32G/K87A related to loss of glycogen binding. We performed 10 ns molecular dynamics (MD) simulation studies in the Gromacs package for both mutations and analyzed the trajectories. From the results, the global properties like root mean square deviation, root mean square fluctuation, radius of gyration, solvent accessible surface area and hydrogen bonds showed structural changes in atomic level observed in W32G and W32G/K87A laforin mutants. The conformational change induced by mutants influenced the loss of the overall stability of the native laforin. Moreover, the change in overall motion of protein was analyzed by principal component analysis and results showed protein clusters expanded more than native and also change in direction in case of double mutant in conformational space. Overall, our report provides theoretical information on loss of structure-function relationship due to flexible nature of laforin mutants. In conclusion, comparative MD simulation studies support the experimental data on W32G and W32G/K87A related to the lafora disease mechanism on glycogen binding.

Single-molecule localization microscopy reveals molecular transactions during RAD51 filament assembly at cellular DNA damage sites

PubMed Central

Haas, Kalina T; Lee, MiYoung; Esposito, Alessandro; Venkitaraman, Ashok R

2018-01-01

Abstract RAD51 recombinase assembles on single-stranded (ss)DNA substrates exposed by DNA end-resection to initiate homologous recombination (HR), a process fundamental to genome integrity. RAD51 assembly has been characterized using purified proteins, but its ultrastructural topography in the cell nucleus is unexplored. Here, we combine cell genetics with single-molecule localization microscopy and a palette of bespoke analytical tools, to visualize molecular transactions during RAD51 assembly in the cellular milieu at resolutions approaching 30–40 nm. In several human cell types, RAD51 focalizes in clusters that progressively extend into long filaments, which abut—but do not overlap—with globular bundles of replication protein A (RPA). Extended filaments alter topographically over time, suggestive of succeeding steps in HR. In cells depleted of the tumor suppressor protein BRCA2, or overexpressing its RAD51-binding BRC repeats, RAD51 fails to assemble at damage sites, although RPA accumulates unhindered. By contrast, in cells lacking a BRCA2 carboxyl (C)-terminal region targeted by cancer-causing mutations, damage-induced RAD51 assemblies initiate but do not extend into filaments. We suggest a model wherein RAD51 assembly proceeds concurrently with end-resection at adjacent sites, via an initiation step dependent on the BRC repeats, followed by filament extension through the C-terminal region of BRCA2. PMID:29309696

Molecular cloning and pharmacological characterization of giant panda (Ailuropoda melanoleuca) melanocortin-4 receptor.

PubMed

Wang, Zhi-Qiang; Wang, Wei; Shi, Lin; Chai, Ji-Tian; Zhang, Xin-Jun; Tao, Ya-Xiong

2016-04-01

The melanocortin-4 receptor (MC4R) is critical in regulating mammalian food intake and energy expenditure. Giant panda (Ailuropoda melanoleuca), famous as the living fossil, is an endangered species endemic to China. We are interested in exploring the functions of the giant panda MC4R (amMC4R) in regulating energy homeostasis and report herein the molecular cloning and pharmacology of the amMC4R. Sequence analysis revealed that amMC4R was highly homologous (>88%) at nucleotide and amino acid sequences to several mammalian MC4Rs. Western blot revealed that the expression construct myc-amMC4R in pcDNA3.1 was successfully constructed and expressed in HEK293T cells. With human MC4R (hMC4R) as a control, pharmacological characteristics of amMC4R were analyzed with binding and signaling assays. Four agonists, including [Nle(4), D-Phe(7)]-α-melanocyte stimulating hormone (NDP-MSH), α- and β-MSH, and a small molecule agonist, THIQ, were used in binding and signaling assays. We showed that amMC4R bound NDP-MSH with the highest affinity followed by THIQ, α-MSH, and β-MSH, with the same ranking order as hMC4R. Treatment of HEK293T cells expressing amMC4R with different concentrations of agonists resulted in dose-dependent increase of intracellular cAMP levels, with similar EC50s for the four agonists. The results suggested that the cloned amMC4R encoded a functional MC4R. The availability of amMC4R and its binding and signaling properties will facilitate the investigation of amMC4R in regulating food intake and energy homeostasis. Copyright © 2016 Elsevier Inc. All rights reserved.

Fatal Toxoplasma gondii infection in the giant panda.

PubMed

Ma, Hongyu; Wang, Zedong; Wang, Chengdong; Li, Caiwu; Wei, Feng; Liu, Quan

2015-01-01

Toxoplasma gondii can infect nearly all warm-blooded animals. We report an acute fatal T. gondii infection in the endangered giant panda (Ailuropoda melanoleuca) in a zoo in China, characterized by acute gastroenteritis and respiratory symptoms. T. gondii infection was confirmed by immunological and molecular methods. Multilocus nested PCR-RFLP revealed clonal type I at the SAG1 and c29-2 loci, clonal type II at the SAG2, BTUB, GRA6, c22-8, and L358 loci, and clonal type III at the alternative SAG2 and SAG3 loci, thus, a potential new genotype of T. gondii in the giant panda. Other possible pathogens were not detected. To our knowledge, this is the first report of clinical toxoplasmosis in a giant panda. © H. Ma et al., published by EDP Sciences, 2015.

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

Environmental Catastrophes in the Earth's History Due to Solar Systems Encounters with Giant Molecular Clouds

NASA Technical Reports Server (NTRS)

Pavlov, Alexander A.

2011-01-01

In its motion through the Milky Way galaxy, the solar system encounters an average density (>=330 H atoms/cubic cm) giant molecular cloud (GMC) approximately every 108 years, a dense (approx 2 x 103 H atoms/cubic cm) GMC every approx 109 years and will inevitably encounter them in the future. However, there have been no studies linking such events with severe (snowball) glaciations in Earth history. Here we show that dramatic climate change can be caused by interstellar dust accumulating in Earth's atmosphere during the solar system's immersion into a dense (approx ,2 x 103 H atoms/cubic cm) GMC. The stratospheric dust layer from such interstellar particles could provide enough radiative forcing to trigger the runaway ice-albedo feedback that results in global snowball glaciations. We also demonstrate that more frequent collisions with less dense GMCs could cause moderate ice ages.

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.

INTERACTION BETWEEN THE SUPERNOVA REMNANT HB 3 AND THE NEARBY STAR-FORMING REGION W3

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

Zhou, Xin; Yang, Ji; Fang, Min

We performed millimeter observations of CO lines toward the supernova remnant (SNR) HB 3. Substantial molecular gas around −45 km s{sup −1} is detected in the conjunction region between the SNR HB 3 and the nearby W3 complex. This molecular gas is distributed along the radio continuum shell of the remnant. Furthermore, the shocked molecular gas indicated by line wing broadening features is also distributed along the radio shell and inside it. By both morphological correspondence and dynamical evidence, we confirm that the SNR HB 3 interacts with the −45 km s{sup −1} molecular cloud (MC), in essence, with the nearby H ii region/MC complexmore » W3. The redshifted line wing broadening features indicate that the remnant is located at the nearside of the MC. With this association, we could place the remnant at the same distance as the W3/W4 complex, which is 1.95 ± 0.04 kpc. The spatial distribution of aggregated young stellar object candidates shows a correlation with the shocked molecular strip associated with the remnant. We also find a binary clump of CO at ( l = 132.°94, b = 1.°12) around −51.5 km s{sup −1} inside the projected extent of the remnant, and it is associated with significant mid-infrared emission. The binary system also has a tail structure resembling the tidal tails of interacting galaxies. According to the analysis of CO emission lines, the larger clump in this binary system is about stable, and the smaller clump is significantly disturbed.« less

Comparison of the recommendations of the AAPM TG-51 and TG-51 addendum reference dosimetry protocols.

PubMed

McCaw, Travis J; Hwang, Min-Sig; Jang, Si Young; Huq, M Saiful

2017-07-01

This work quantified differences between recommendations of the TG-51 and TG-51 addendum reference dosimetry protocols. Reference dosimetry was performed for flattened photon beams with nominal energies of 6, 10, 15, and 23 MV, as well as flattening-filter free (FFF) beam energies of 6 and 10 MV, following the recommendations of both the TG-51 and TG-51 addendum protocols using both a Farmer ® ionization chamber and a scanning ionization chamber with calibration coefficients traceable to absorbed dose-to-water (D w ) standards. Differences in D w determined by the two protocols were 0.1%-0.3% for beam energies with a flattening filter, and up to 0.2% and 0.8% for FFF beams measured with the scanning and Farmer ® ionization chambers, respectively, due to k Q determination, volume-averaging correction, and collimator jaw setting. Combined uncertainty was between 0.91% and 1.2% (k = 1), varying by protocol and detector. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Highly conserved Z and molecularly diverged W chromosomes in the fish genus Triportheus (Characiformes, Triportheidae).

PubMed

Yano, C F; Bertollo, L A C; Ezaz, T; Trifonov, V; Sember, A; Liehr, T; Cioffi, M B

2017-03-01

The main objectives of this study were to test: (1) whether the W-chromosome differentiation matches to species' evolutionary divergence (phylogenetic concordance) and (2) whether sex chromosomes share a common ancestor within a congeneric group. The monophyletic genus Triportheus (Characiformes, Triportheidae) was the model group for this study. All species in this genus so far analyzed have ZW sex chromosome system, where the Z is always the largest chromosome of the karyotype, whereas the W chromosome is highly variable ranging from almost homomorphic to highly heteromorphic. We applied conventional and molecular cytogenetic approaches including C-banding, ribosomal DNA mapping, comparative genomic hybridization (CGH) and cross-species whole chromosome painting (WCP) to test our questions. We developed Z- and W-chromosome paints from T. auritus for cross-species WCP and performed CGH in a representative species (T. signatus) to decipher level of homologies and rates of differentiation of W chromosomes. Our study revealed that the ZW sex chromosome system had a common origin, showing highly conserved Z chromosomes and remarkably divergent W chromosomes. Notably, the W chromosomes have evolved to different shapes and sequence contents within ~15-25 Myr of divergence time. Such differentiation highlights a dynamic process of W-chromosome evolution within congeneric species of Triportheus.

Giant panda conservation science: how far we have come.

PubMed

Swaisgood, Ronald R; Wei, Fuwen; Wildt, David E; Kouba, Andrew J; Zhang, Zejun

2010-04-23

The giant panda is a conservation icon, but science has been slow to take up its cause in earnest. In the past decade, researchers have been making up for lost time, as reflected in the flurry of activity reported at the symposium Conservation Science for Giant Pandas and Their Habitat at the 2009 International Congress for Conservation Biology (ICCB) in Beijing. In reports addressing topics ranging from spatial ecology to molecular censusing, from habitat recovery in newly established reserves to earthquake-induced habitat loss, from new insights into factors limiting carrying capacity to the uncertain effects of climate change, this symposium displayed the vibrant and blossoming application of science to giant panda conservation. Collectively, we find that we have come a long way, but we also reach an all-too-familiar conclusion: the more we know, the more challenges are revealed. While many earlier findings are supported, many of our assumptions are debatable. Here we discuss recent advancements in conservation science for giant pandas and suggest that the way forward is more direct application of emerging science to management and policy.

Evolved massive stars in W33 and in GMC 23.3-0.3

NASA Astrophysics Data System (ADS)

Messineo, Maria; Clark, J. Simon; Figer, Donald F.; Menten, Karl M.; Kudritzki, Rolf-Peter; Najarro, Francisco; Rich, Michael; Ivanov, Valentin D.; Valenti, Elena; Trombley, Christine; Chen, Rosie; Davies, Ben; MacKenty, John W.

2015-08-01

We have conducted an infrared spectroscopic survey for massive evolved stars and/or clusters in the Galactic giant molecular clouds G23.3-0.3 and W33. A large number of extraordinary sub-clumps/clusters of massive stars were detected. The spatial and temporal distribution of these massive stars yields information on the star formation history of the clouds.In G23.3-0.3, we discovered a dozen massive O-type stars, one candidate luminous blue variable, and several red supergiants. The O-type stars have masses from 25 to 50 Msun and ages of 5-8 Myr, while the RSGs belong to a burst that occurred 20-30 Myr ago. Therefore, GMC G23.3-0.3 has had one of the longest known histories of star formation (20-30 Myr). GMC G23.3-0.3 is rich in HII regions and supernova remnants; we detected massive stars in the cores of SNR W41 and of SNR G22.7-0.2.In W33, we detected a few evolved O-type stars and one Wolf-Rayet star, but none of the late-type objects has the luminosity of a red supergiant. W33 is characterized by discrete sources and has had at least 3-5 Myr of star formation history, which is now propagating from west to east. While our detections of massive evolved stars in W33 are made on the west side of the cloud, several dense molecular cores that may harbor proto clusters have recently been detected on the east side of the cloud by Immer et al. (2014).Messineo, Maria; Menten, Karl M.; Figer, Donald F.; Davies, Ben; Clark, J. Simon; Ivanov, Valentin D.Kudritzki, Rolf-Peter; Rich, R. Michael; MacKenty, John W.; Trombley, Christine 2014A&A...569A..20MMessineo, Maria; Clark, J. Simon; Figer, Donald F.; Kudritzki, Rolf-Peter; Francisco, Najarro; Rich, R. Michael; Menten, Karl M.; Ivanov, Valentin D.; Valenti, Elena; Trombley, Christine; Chen, C.H. Rosie; Davies, Ben; submitted to ApJ.

GW100: Benchmarking G0W0 for Molecular Systems.

PubMed

van Setten, Michiel J; Caruso, Fabio; Sharifzadeh, Sahar; Ren, Xinguo; Scheffler, Matthias; Liu, Fang; Lischner, Johannes; Lin, Lin; Deslippe, Jack R; Louie, Steven G; Yang, Chao; Weigend, Florian; Neaton, Jeffrey B; Evers, Ferdinand; Rinke, Patrick

2015-12-08

We present the GW100 set. GW100 is a benchmark set of the ionization potentials and electron affinities of 100 molecules computed with the GW method using three independent GW codes and different GW methodologies. The quasi-particle energies of the highest-occupied molecular orbitals (HOMO) and lowest-unoccupied molecular orbitals (LUMO) are calculated for the GW100 set at the G0W0@PBE level using the software packages TURBOMOLE, FHI-aims, and BerkeleyGW. The use of these three codes allows for a quantitative comparison of the type of basis set (plane wave or local orbital) and handling of unoccupied states, the treatment of core and valence electrons (all electron or pseudopotentials), the treatment of the frequency dependence of the self-energy (full frequency or more approximate plasmon-pole models), and the algorithm for solving the quasi-particle equation. Primary results include reference values for future benchmarks, best practices for convergence within a particular approach, and average error bars for the most common approximations.

The Bamboo-Eating Giant Panda (Ailuropoda melanoleuca) Has a Sweet Tooth: Behavioral and Molecular Responses to Compounds That Taste Sweet to Humans

PubMed Central

Jiang, Peihua; Li, Xia; Brand, Joseph G.; Margolskee, Robert F.; Reed, Danielle R.; Beauchamp, Gary K.

2014-01-01

A growing body of behavioral and genetic information indicates that taste perception and food sources are highly coordinated across many animal species. For example, sweet taste perception is thought to serve to detect and motivate consumption of simple sugars in plants that provide calories. Supporting this is the observation that most plant-eating mammals examined exhibit functional sweet perception, whereas many obligate carnivores have independently lost function of their sweet taste receptors and exhibit no avidity for simple sugars that humans describe as tasting sweet. As part of a larger effort to compare taste structure/function among species, we examined both the behavioral and the molecular nature of sweet taste in a plant-eating animal that does not consume plants with abundant simple sugars, the giant panda (Ailuropoda melanoleuca). We evaluated two competing hypotheses: as plant-eating mammals, they should have a well-developed sweet taste system; however, as animals that do not normally consume plants with simple sugars, they may have lost sweet taste function, as has occurred in strict carnivores. In behavioral tests, giant pandas avidly consumed most natural sugars and some but not all artificial sweeteners. Cell-based assays revealed similar patterns of sweet receptor responses toward many of the sweeteners. Using mixed pairs of human and giant panda sweet taste receptor units (hT1R2+gpT1R3 and gpT1R2+hT1R3) we identified regions of the sweet receptor that may account for behavioral differences in giant pandas versus humans toward various sugars and artificial sweeteners. Thus, despite the fact that the giant panda's main food, bamboo, is very low in simple sugars, the species has a marked preference for several compounds that taste sweet to humans. We consider possible explanations for retained sweet perception in this species, including the potential extra-oral functions of sweet taste receptors that may be required for animals that consume

The bamboo-eating giant panda (Ailuropoda melanoleuca) has a sweet tooth: behavioral and molecular responses to compounds that taste sweet to humans.

PubMed

Jiang, Peihua; Josue-Almqvist, Jesusa; Jin, Xuelin; Li, Xia; Brand, Joseph G; Margolskee, Robert F; Reed, Danielle R; Beauchamp, Gary K

2014-01-01

A growing body of behavioral and genetic information indicates that taste perception and food sources are highly coordinated across many animal species. For example, sweet taste perception is thought to serve to detect and motivate consumption of simple sugars in plants that provide calories. Supporting this is the observation that most plant-eating mammals examined exhibit functional sweet perception, whereas many obligate carnivores have independently lost function of their sweet taste receptors and exhibit no avidity for simple sugars that humans describe as tasting sweet. As part of a larger effort to compare taste structure/function among species, we examined both the behavioral and the molecular nature of sweet taste in a plant-eating animal that does not consume plants with abundant simple sugars, the giant panda (Ailuropoda melanoleuca). We evaluated two competing hypotheses: as plant-eating mammals, they should have a well-developed sweet taste system; however, as animals that do not normally consume plants with simple sugars, they may have lost sweet taste function, as has occurred in strict carnivores. In behavioral tests, giant pandas avidly consumed most natural sugars and some but not all artificial sweeteners. Cell-based assays revealed similar patterns of sweet receptor responses toward many of the sweeteners. Using mixed pairs of human and giant panda sweet taste receptor units (hT1R2+gpT1R3 and gpT1R2+hT1R3) we identified regions of the sweet receptor that may account for behavioral differences in giant pandas versus humans toward various sugars and artificial sweeteners. Thus, despite the fact that the giant panda's main food, bamboo, is very low in simple sugars, the species has a marked preference for several compounds that taste sweet to humans. We consider possible explanations for retained sweet perception in this species, including the potential extra-oral functions of sweet taste receptors that may be required for animals that consume

High molecular weight lectin isolated from the mucus of the giant African snail Achatina fulica.

PubMed

Ito, Shigeru; Shimizu, Masahiro; Nagatsuka, Maki; Kitajima, Seiji; Honda, Michiyo; Tsuchiya, Takahide; Kanzawa, Nobuyuki

2011-01-01

To understand better the host defense mechanisms of mollusks against pathogens, we examined the anti-microbial activity of mucus from the giant African snail Achatina fulica. Hemagglutination activity of the mucus secreted by the integument of snails inoculated with Escherichia coli was observed to increase and to cause hemagglutination of rabbit red blood cells. Purification of the snail mucus lectin by sequential column chromatography revealed that the relative molecular mass of the lectin was 350 kDa. The hemagglutination activity of the lectin was Ca(2+)-dependent and was inhibited by galactose. Growth arrest tests showed that the lectin did not inhibit bacterial growth, but did induce agglutination of gram-positive and gram-negative bacteria. Tissue distribution analyses using a polyclonal antibody revealed that the lectin was expressed in the tissues of the mantle collar. The lectin isolated from the mucus of the snail appeared to contribute to its innate immunity.

Dense gas and star formation in individual Giant Molecular Clouds in M31

NASA Astrophysics Data System (ADS)

Viaene, S.; Forbrich, J.; Fritz, J.

2018-04-01

Studies both of entire galaxies and of local Galactic star formation indicate a dependency of a molecular cloud's star formation rate (SFR) on its dense gas mass. In external galaxies, such measurements are derived from HCN(1-0) observations, usually encompassing many Giant Molecular Clouds (GMCs) at once. The Andromeda galaxy (M31) is a unique laboratory to study the relation of the SFR and HCN emission down to GMC scales at solar-like metallicities. In this work, we correlate our composite SFR determinations with archival HCN, HCO+, and CO observations, resulting in a sample of nine reasonably representative GMCs. We find that, at the scale of individual clouds, it is important to take into account both obscured and unobscured star formation to determine the SFR. When correlated against the dense-gas mass from HCN, we find that the SFR is low, in spite of these refinements. We nevertheless retrieve an SFR-dense-gas mass correlation, confirming that these SFR tracers are still meaningful on GMC scales. The correlation improves markedly when we consider the HCN/CO ratio instead of HCN by itself. This nominally indicates a dependency of the SFR on the dense-gas fraction, in contradiction to local studies. However, we hypothesize that this partly reflects the limited dynamic range in dense-gas mass, and partly that the ratio of single-pointing HCN and CO measurements may be less prone to systematics like sidelobes. In this case, the HCN/CO ratio would importantly be a better empirical measure of the dense-gas content itself.

The Global Evolution of Giant Molecular Clouds. I. Model Formulation and Quasi-Equilibrium Behavior

NASA Astrophysics Data System (ADS)

Krumholz, Mark R.; Matzner, Christopher D.; McKee, Christopher F.

2006-12-01

We present semianalytic dynamical models for giant molecular clouds evolving under the influence of H II regions launched by newborn star clusters. In contrast to previous work, we neither assume that clouds are in virial or energetic equilibrium, nor do we ignore the effects of star formation feedback. The clouds, which we treat as spherical, can expand and contract homologously. Photoionization drives mass ejection; the recoil of cloud material both stirs turbulent motions and leads to an effective confining pressure. The balance between these effects and the decay of turbulent motions through isothermal shocks determines clouds' dynamical and energetic evolution. We find that for realistic values of the rates of turbulent dissipation, photoevaporation, and energy injection by H II regions, the massive clouds where most molecular gas in the Galaxy resides live for a few crossing times, in good agreement with recent observational estimates that large clouds in Local Group galaxies survive roughly 20-30 Myr. During this time clouds remain close to equilibrium, with virial parameters of 1-3 and column densities near 1022 H atoms cm-2, also in agreement with observed cloud properties. Over their lives they convert 5%-10% of their mass into stars, after which point most clouds are destroyed when a large H II region unbinds them. In contrast, small clouds like those found in the solar neighborhood only survive ~1 crossing time before being destroyed.

Giant molecular filaments in the Milky Way. II. The fourth Galactic quadrant

NASA Astrophysics Data System (ADS)

Abreu-Vicente, J.; Ragan, S.; Kainulainen, J.; Henning, Th.; Beuther, H.; Johnston, K.

2016-05-01

Context. Filamentary structures are common morphological features of the cold, molecular interstellar medium (ISM). Recent studies have discovered massive, hundred-parsec-scale filaments that may be connected to the large-scale, Galactic spiral arm structure. Addressing the nature of these giant molecular filaments (GMFs) requires a census of their occurrence and properties. Aims: We perform a systematic search of GMFs in the fourth Galactic quadrant and determine their basic physical properties. Methods: We identify GMFs based on their dust extinction signatures in the near- and mid-infrared and the velocity structure probed by 13CO line emission. We use the 13CO line emission and ATLASGAL dust emission data to estimate the total and dense gas masses of the GMFs. We combine our sample with an earlier sample from literature and study the Galactic environment of the GMFs. Results: We identify nine GMFs in the fourth Galactic quadrant: six in the Centaurus spiral arm and three in inter-arm regions. Combining this sample with an earlier study using the same identification criteria in the first Galactic quadrant results in 16 GMFs, nine of which are located within spiral arms. The GMFs have sizes of 80-160 pc and 13CO-derived masses between 5-90 × 104M⊙. Their dense gas mass fractions are between 1.5-37%, which is higher in the GMFs connected to spiral arms. We also compare the different GMF-identification methods and find that emission and extinction-based techniques overlap only partially, thereby highlighting the need to use both to achieve a complete census. Table A.2 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/590/A131

Detailed modelling of the circumstellar molecular line emission of the S-type AGB star W Aquilae

NASA Astrophysics Data System (ADS)

Danilovich, T.; Bergman, P.; Justtanont, K.; Lombaert, R.; Maercker, M.; Olofsson, H.; Ramstedt, S.; Royer, P.

2014-09-01

Context. S-type AGB stars have a C/O ratio which suggests that they are transition objects between oxygen-rich M-type stars and carbon-rich C-type stars. As such, their circumstellar compositions of gas and dust are thought to be sensitive to their precise C/O ratio, and it is therefore of particular interest to examine their circumstellar properties. Aims: We present new Herschel HIFI and PACS sub-millimetre and far-infrared line observations of several molecular species towards the S-type AGB star W Aql. We use these observations, which probe a wide range of gas temperatures, to constrain the circumstellar properties of W Aql, including mass-loss rate and molecular abundances. Methods: We used radiative transfer codes to model the circumstellar dust and molecular line emission to determine circumstellar properties and molecular abundances. We assumed a spherically symmetric envelope formed by a constant mass-loss rate driven by an accelerating wind. Our model includes fully integrated H2O line cooling as part of the solution of the energy balance. Results: We detect circumstellar molecular lines from CO, H2O, SiO, HCN, and, for the first time in an S-type AGB star, NH3. The radiative transfer calculations result in an estimated mass-loss rate for W Aql of 4.0 × 10-6 M⊙ yr-1 based on the 12CO lines. The estimated 12CO/13CO ratio is 29, which is in line with ratios previously derived for S-type AGB stars. We find an H2O abundance of 1.5 × 10-5, which is intermediate to the abundances expected for M and C stars, and an ortho/para ratio for H2O that is consistent with formation at warm temperatures. We find an HCN abundance of 3 × 10-6, and, although no CN lines are detected using HIFI, we are able to put some constraints on the abundance, 6 × 10-6, and distribution of CN in W Aql's circumstellar envelopeusing ground-based data. We find an SiO abundance of 3 × 10-6, and an NH3 abundance of 1.7 × 10-5, confined to a small envelope. If we include uncertainties

Molecular detection and quantification of viable probiotic strains in animal feedstuffs using the commercial direct fed microbial Lactobacillus animalis NP51 as a model.

PubMed

Ayala, D I; Chen, J C; Bugarel, M; Loneragan, G H; den Bakker, H C; Kottapalli, K R; Brashears, M M; Nightingale, K K

2018-04-17

Lactobacillus animalis NP51 is a direct-fed microbial strain (DFM) extensively used as a pre-harvest food safety mitigation in feedlot cattle due to its antagonistic effects against human foodborne pathogens such as Salmonella and Escherichia coli O157:H7. NP51 not only promotes overall gut health but interferes with the ability of these pathogens to colonize the gastrointestinal tract of cattle. As a result, NP51 reduces fecal shedding of Salmonella and E. coli O157:H7 in cattle presented for harvest and the load of these pathogens that enter the human food chain. Cattle are administered a high dose (1 × 10 9  CFU/head/day) of NP51 to reduce fecal shedding of foodborne pathogens. Ensiled animal feedstuffs naturally contain a high load of lactic acid bacteria (LAB) and it is not possible to detect and quantify the level of a specific LAB strain (e.g., NP51) in this matrix using traditional microbiological culture. The purpose of this study was to develop a molecular method to detect and quantify viable populations of a specific LAB strain (e.g., NP51) in cattle feedstuffs. The NP51 whole genome sequence was aligned with closely related LAB clustering within the same well-supported clade in a LAB phylogeny derived from 30 conserved amino acid encoding sequence to identify orthologs. A sequence encoding recombinational DNA repair protein RecT was found to be unique to NP51 and used to design primers and a probe for molecular detection and quantification of NP51. The primers and probe were confirmed to be specific to NP51 in vitro. Total RNA was extracted from silage samples, including samples naturally inoculated in the field and control samples that were artificially spiked with a range of NP51 concentrations in the laboratory. Reverse-transcriptase quantitative real-time (RT-qRTi) PCR was used to quantify cDNA copies in samples and cycle threshold (Ct) values were compared to a standard curve to estimate NP51 concentrations. Our results indicate this novel

Rediscovering the Giant Low Surface Brightness Spiral Galaxy Malin 1

NASA Astrophysics Data System (ADS)

Galaz, Gaspar

2018-01-01

I summarize the latest discoveries regarding this ramarkable diffuse and giant galaxy, the largest single spiral in the universe so far. I describe how the latest discoveries could have been done easily 20 years ago, but an incredible summation of facts and some astronomical sociology, keeped many of them undisclosed. I present the most conspicuous features of the giant spiral arms of Malin 1, including stellar density, colors, stellar populations and some modeling describing their past evolution to the current state. I conclude with pending issues regarding stellar formation in Malin 1, and the efforts to detect its elusive molecular gas.

SMA OBSERVATIONS OF THE W3(OH) COMPLEX: PHYSICAL AND CHEMICAL DIFFERENTIATION BETWEEN W3(H{sub 2}O) AND W3(OH)

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

Qin, Sheng-Li; Schilke, Peter; Sánchez-Monge, Álvaro

2015-04-10

We report on the Submillimeter Array (SMA) observations of molecular lines at 270 GHz toward the W3(OH) and W3(H{sub 2}O) complex. Although previous observations already resolved the W3(H{sub 2}O) into two or three sub-components, the physical and chemical properties of the two sources are not well constrained. Our SMA observations clearly resolved the W3(OH) and W3(H{sub 2}O) continuum cores. Taking advantage of the line fitting tool XCLASS, we identified and modeled a rich molecular spectrum in this complex, including multiple CH{sub 3}CN and CH{sub 3}OH transitions in both cores. HDO, C{sub 2}H{sub 5}CN, O{sup 13}CS, and vibrationally excited lines ofmore » HCN, CH{sub 3}CN, and CH{sub 3}OCHO were only detected in W3(H{sub 2}O). We calculate gas temperatures and column densities for both cores. The results show that W3(H{sub 2}O) has higher gas temperatures and larger column densities than W3(OH) as previously observed, suggesting physical and chemical differences between the two cores. We compare the molecular abundances in W3(H{sub 2}O) to those in the Sgr B2(N) hot core, the Orion KL hot core, and the Orion Compact Ridge, and discuss the chemical origin of specific species. An east–west velocity gradient is seen in W3(H{sub 2}O), and the extension is consistent with the bipolar outflow orientation traced by water masers and radio jets. A north–south velocity gradient across W3(OH) is also observed. However, with current observations we cannot be assured whether the velocity gradients are caused by rotation, outflow, or radial velocity differences of the sub-components of W3(OH)« less

Molecular rotational line profiles from oxygen-rich red giant winds

NASA Technical Reports Server (NTRS)

Justtanont, K.; Skinner, C. J.; Tielens, A. G. G. M.

1994-01-01

We have developed a radiative transfer model of the dust and gas envelopes around late-type stars. The gas kinetic temperature for each star is calculated by solving equations of motion and the energy balance simultaneously. The main processes include viscous heating and adiabatic and radiative cooling. Heating is dominated by viscosity as the grains stream outward through the gas, with some contribution in oxygen-rich stars by near-IR pumping of H2O followed by collisional de-excitation in the inner envelope. For O-rich stars, rotational H2O cooling is a dominant mechanism in the middle part of the envelope, with CO cooling being less significant. We have applied our model to three well-studied oxygen-rich red giant stars. The three stars cover a wide range of mass-loss rates, and hence they have different temperature structures. The derived temperature structures are used in calculating CO line profiles for these objects. Comparison of the dust and gas mass-loss rates suggests that mass-loss rates are not constant during the asymptotic giant branch phase. In particular, the results show that the low CO 1-0 antenna temperatures of OH/IR stars reflect an earlier phase of much lower mass-loss rate.

Star formation induced by cloud-cloud collisions and galactic giant molecular cloud evolution

NASA Astrophysics Data System (ADS)

Kobayashi, Masato I. N.; Kobayashi, Hiroshi; Inutsuka, Shu-ichiro; Fukui, Yasuo

2018-05-01

Recent millimeter/submillimeter observations towards nearby galaxies have started to map the whole disk and to identify giant molecular clouds (GMCs) even in the regions between galactic spiral structures. Observed variations of GMC mass functions in different galactic environments indicates that massive GMCs preferentially reside along galactic spiral structures whereas inter-arm regions have many small GMCs. Based on the phase transition dynamics from magnetized warm neutral medium to molecular clouds, Kobayashi et al. (2017, ApJ, 836, 175) proposes a semi-analytical evolutionary description for GMC mass functions including a cloud-cloud collision (CCC) process. Their results show that CCC is less dominant in shaping the mass function of GMCs than the accretion of dense H I gas driven by the propagation of supersonic shock waves. However, their formulation does not take into account the possible enhancement of star formation by CCC. Millimeter/submillimeter observations within the Milky Way indicate the importance of CCC in the formation of star clusters and massive stars. In this article, we reformulate the time-evolution equation largely modified from Kobayashi et al. (2017, ApJ, 836, 175) so that we additionally compute star formation subsequently taking place in CCC clouds. Our results suggest that, although CCC events between smaller clouds are more frequent than the ones between massive GMCs, CCC-driven star formation is mostly driven by massive GMCs ≳ 10^{5.5} M_{⊙} (where M⊙ is the solar mass). The resultant cumulative CCC-driven star formation may amount to a few 10 percent of the total star formation in the Milky Way and nearby galaxies.

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.

Gas, dust, stars, star formation, and their evolution in M 33 at giant molecular cloud scales

NASA Astrophysics Data System (ADS)

Komugi, Shinya; Miura, Rie E.; Kuno, Nario; Tosaki, Tomoka

2018-06-01

We report on a multi-parameter analysis of giant molecular clouds (GMCs) in the nearby spiral galaxy M 33. A catalog of GMCs identifed in 12CO(J = 3-2) was used to compile associated 12CO(J = 1-0), dust, stellar mass, and star formation rate. Each of the 58 GMCs are categorized by their evolutionary stage. Applying the principal component analysis on these parameters, we construct two principal components, PC1 and PC2, which retain 75% of the information from the original data set. PC1 is interpreted as expressing the total interstellar matter content, and PC2 as the total activity of star formation. Young (< 10 Myr) GMCs occupy a distinct region in the PC1-PC2 plane, with lower interstellar medium (ISM) content and star formation activity compared to intermediate-age and older clouds. Comparison of average cloud properties in different evolutionary stages imply that GMCs may be heated or grow denser and more massive via aggregation of diffuse material in their first ˜ 10 Myr. The PCA also objectively identified a set of tight relations between ISM and star formation. The ratio of the two CO lines is nearly constant, but weakly modulated by massive star formation. Dust is more strongly correlated with the star formation rate than the CO lines, supporting recent findings that dust may trace molecular gas better than CO. Stellar mass contributes weakly to the star formation rate, reminiscent of an extended form of the Schmidt-Kennicutt relation with the molecular gas term substituted by dust.

Gas, dust, stars, star formation, and their evolution in M 33 at giant molecular cloud scales

NASA Astrophysics Data System (ADS)

Komugi, Shinya; Miura, Rie E.; Kuno, Nario; Tosaki, Tomoka

2018-04-01

We report on a multi-parameter analysis of giant molecular clouds (GMCs) in the nearby spiral galaxy M 33. A catalog of GMCs identifed in 12CO(J = 3-2) was used to compile associated 12CO(J = 1-0), dust, stellar mass, and star formation rate. Each of the 58 GMCs are categorized by their evolutionary stage. Applying the principal component analysis on these parameters, we construct two principal components, PC1 and PC2, which retain 75% of the information from the original data set. PC1 is interpreted as expressing the total interstellar matter content, and PC2 as the total activity of star formation. Young (< 10 Myr) GMCs occupy a distinct region in the PC1-PC2 plane, with lower interstellar medium (ISM) content and star formation activity compared to intermediate-age and older clouds. Comparison of average cloud properties in different evolutionary stages imply that GMCs may be heated or grow denser and more massive via aggregation of diffuse material in their first ˜ 10 Myr. The PCA also objectively identified a set of tight relations between ISM and star formation. The ratio of the two CO lines is nearly constant, but weakly modulated by massive star formation. Dust is more strongly correlated with the star formation rate than the CO lines, supporting recent findings that dust may trace molecular gas better than CO. Stellar mass contributes weakly to the star formation rate, reminiscent of an extended form of the Schmidt-Kennicutt relation with the molecular gas term substituted by dust.

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.

The Magnetic Field Structure of W3(OH)

NASA Astrophysics Data System (ADS)

El-Batal, Adham M.; Clemens, Dan P.; Montgomery, Jordan

2018-06-01

Situated in the Perseus arm of the Galaxy, the W3 molecular cloud is a high-mass star-forming region with low foreground optical extinction. Near-infrared H- and K-band polarimetric observations of a 10' × 10' field of view of W3 were obtained using the Mimir instrument on the 1.8 m Perkins Telescope. This field of view encompasses W3(OH), a region of OH and H2O masers as well as an HII region. The H-band data were used in conjunction with Spitzer M-band data to map extinction via H-M color excess. In total, 2654 stellar objects were found in the Mimir field of view, of which 1013 had H and M magnitudes with low errors. Using the extinction map and the individual stellar H-M color excess values, 429 stars with polarized signals were found to be background to the molecular cloud. These were useful for mapping the magnetic field structure and estimating the magnetic field strength of the cloud. Mid- to far-infrared (70 - 870 μm) archival Herschel and Planck data were used to map dust extinction at 850 µm and create an H2 column density map. Combined, maps of magnetic field strength and hydrogen column density can be used to infer the ratio of gravitational potential to magnetic potential ( M/Φ ). Findings are discussed in the context of M/Φ ratio in models and the stability of high-mass star-forming regions.This work has been supported by NSF AST14-12269 and NASA NNX15AE51G grants.

FK506 binding protein 51 integrates pathways of adaptation: FKBP51 shapes the reactivity to environmental change.

PubMed

Rein, Theo

2016-09-01

This review portraits FK506 binding protein (FKBP) 51 as "reactivity protein" and collates recent publications to develop the concept of FKBP51 as contributor to different levels of adaptation. Adaptation is a fundamental process that enables unicellular and multicellular organisms to adjust their molecular circuits and structural conditions in reaction to environmental changes threatening their homeostasis. FKBP51 is known as chaperone and co-chaperone of heat shock protein (HSP) 90, thus involved in processes ensuring correct protein folding in response to proteotoxic stress. In mammals, FKBP51 both shapes the stress response and is calibrated by the stress levels through an ultrashort molecular feedback loop. More recently, it has been linked to several intracellular pathways related to the reactivity to drug exposure and stress. Through its role in autophagy and DNA methylation in particular it influences adaptive pathways, possibly also in a transgenerational fashion. Also see the video abstract here. © 2016 WILEY Periodicals, Inc.

Interaction mechanism exploration of R-bicalutamide/S-1 with WT/W741L AR using molecular dynamics simulations.

PubMed

Liu, Hongli; An, Xiaoli; Li, Shuyan; Wang, Yuwei; Li, Jiazhong; Liu, Huanxiang

2015-12-01

R-Bicalutamide is a first generation antiandrogen used to treat prostate cancer, which inhibits androgen action by competitively binding to the androgen receptor (AR). However, R-bicalutamide was discovered to exhibit some agonistic properties in clinical application. According to reports, the W741L AR mutation may lead to resistance towards R-bicalutamide. But the mechanism of the R-bicalutamide switch from an antagonist to an agonist due to the mutation of AR W741L is still not so clear. Another molecule, S-1, owing to a very similar structure to R-bicalutamide, is always agonistic to both the wild type and W741L AR. The main difference between these two chemicals is that S-1 has an ether linkage while R-bicalutamide has a sulfonyl group. To study the drug-resistant mechanism caused by W741L mutation and the opposite effects arising from subtle structure differences, molecular dynamics (MD) simulations and molecular mechanics generalized Born surface area (MM-GBSA) calculations were employed to explore the interaction mechanisms between R-bicalutamide/S-1 and WT/W741L AR. The calculated binding free energies are in accordance with the reported experimental values. The obtained results indicate that M895 and W741 are vital amino acids in the antagonism of R-bicalutamide. The bulkier substitution of sulfonyl and tryptophan push aside M895, together with helix 12 (H12), to expose the ligand-binding domain resulting in the antagonistic conformation of the AR. If W741 is mutated to L741, the B-ring of these two chemicals would shift toward L741. At the same time, M895 dragging helix H12, would also move closer to L741. So H12 tends to cover the AR ligand-binding domain to a certain degree, changing the androgen receptor from an antagonistic to an agonistic conformation, which may explain the agonism of R-bicalutamide to the mutant W741L AR.

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.

Time evolution of giant molecular cloud mass functions with cloud-cloud collisions and gas resurrection in various environments

NASA Astrophysics Data System (ADS)

Kobayashi, M. I. N.; Inutsuka, S.; Kobayashi, H.; Hasegawa, K.

We formulate the evolution equation for the giant molecular cloud (GMC) mass functions including self-growth of GMCs through the thermal instability, self-dispersal due to massive stars born in GMCs, cloud-cloud collisions (CCCs), and gas resurrection that replenishes the minimum-mass GMC population. The computed time evolutions obtained from this formulation suggest that the slope of GMC mass function in the mass range <105.5 Mȯ is governed by the ratio of GMC formation timescale to its dispersal timescale, and that the CCC process modifies only the massive end of the mass function. Our results also suggest that most of the dispersed gas contributes to the mass growth of pre-existing GMCs in arm regions whereas less than 60 per cent contributes in inter-arm regions.

Geometries and properties of bimetallic phosphido-bridged complex Cp(CO) 2W(μ-PPh 2)W(CO) 5 and Cp(CO) 3W(μ-PPh 2)W(CO) 5

NASA Astrophysics Data System (ADS)

Wang, Fang; Yang, Hongmei; Yang, Zuoyin; Zhang, Jingchang; Cao, Weiliang

2007-01-01

Complete geometry optimizations were carried out by HF and DFT methods to study the molecular structure of binuclear transition-metal compounds (Cp(CO) 3W(μ-PPh 2)W(CO) 5) (I) and (Cp(CO) 2W(μ-PPh 2)W(CO) 5) (II). A comparison of the experimental data and calculated structural parameters demonstrates that the most accurate geometry parameters are predicted by the MPW1PW91/LANL2DZ among the three DFT methods. Topological properties of molecular charge distributions were analyzed with the theory of atoms in molecules. (3, -1) critical points, namely bond critical point, were found between the two tungsten atoms, and between W1 and C10 in complex II, which confirms the existence of the metal-metal bond and a semi-bridging CO between the two tungsten atoms. The result provided a theoretical guidance of detailed study on the binuclear phosphido-bridged complex containing transition metal-metal bond, which could be useful in the further study of the heterobimetallic phosphido-bridged complexes.

Giant surfactants provide a versatile platform for sub-10-nm nanostructure engineering

PubMed Central

Yu, Xinfei; Yue, Kan; Hsieh, I-Fan; Li, Yiwen; Dong, Xue-Hui; Liu, Chang; Xin, Yu; Wang, Hsiao-Fang; Shi, An-Chang; Newkome, George R.; Chen, Er-Qiang; Zhang, Wen-Bin; Cheng, Stephen Z. D.

2013-01-01

The engineering of structures across different length scales is central to the design of novel materials with controlled macroscopic properties. Herein, we introduce a unique class of self-assembling materials, which are built upon shape- and volume-persistent molecular nanoparticles and other structural motifs, such as polymers, and can be viewed as a size-amplified version of the corresponding small-molecule counterparts. Among them, “giant surfactants” with precise molecular structures have been synthesized by “clicking” compact and polar molecular nanoparticles to flexible polymer tails of various composition and architecture at specific sites. Capturing the structural features of small-molecule surfactants but possessing much larger sizes, giant surfactants bridge the gap between small-molecule surfactants and block copolymers and demonstrate a duality of both materials in terms of their self-assembly behaviors. The controlled structural variations of these giant surfactants through precision synthesis further reveal that their self-assemblies are remarkably sensitive to primary chemical structures, leading to highly diverse, thermodynamically stable nanostructures with feature sizes around 10 nm or smaller in the bulk, thin-film, and solution states, as dictated by the collective physical interactions and geometric constraints. The results suggest that this class of materials provides a versatile platform for engineering nanostructures with sub-10-nm feature sizes. These findings are not only scientifically intriguing in understanding the chemical and physical principles of the self-assembly, but also technologically relevant, such as in nanopatterning technology and microelectronics. PMID:23716680

Fast Winds and Mass Loss from Metal-Poor Field Giants

NASA Astrophysics Data System (ADS)

Dupree, A. K.; Smith, Graeme H.; Strader, Jay

2009-11-01

Echelle spectra of the infrared He I λ10830 line were obtained with NIRSPEC on the Keck 2 telescope for 41 metal-deficient field giant stars including those on the red giant branch (RGB), asymptotic giant branch (AGB), and red horizontal branch (RHB). The presence of this He I line is ubiquitous in stars with T effgsim 4500 K and MV fainter than -1.5, and reveals the dynamics of the atmosphere. The line strength increases with effective temperature for T effgsim 5300 K in RHB stars. In AGB and RGB stars, the line strength increases with luminosity. Fast outflows (gsim 60 km s-1) are detected from the majority of the stars and about 40% of the outflows have sufficient speed as to allow escape of material from the star as well as from a globular cluster. Outflow speeds and line strengths do not depend on metallicity for our sample ([Fe/H]= -0.7 to -3.0), suggesting the driving mechanism for these winds derives from magnetic and/or hydrodynamic processes. Gas outflows are present in every luminous giant, but are not detected in all stars of lower luminosity indicating possible variability. Mass loss rates ranging from ~3 × 10-10 to ~6 × 10-8 M sun yr-1 estimated from the Sobolev approximation for line formation represent values with evolutionary significance for red giants and RHB stars. We estimate that 0.2 M sun will be lost on the RGB, and the torque of this wind can account for observations of slowly rotating RHB stars in the field. About 0.1-0.2 M sun will be lost on the RHB itself. This first empirical determination of mass loss on the RHB may contribute to the appearance of extended horizontal branches in globular clusters. The spectra appear to resolve the problem of missing intracluster material in globular clusters. Opportunities exist for "wind smothering" of dwarf stars by winds from the evolved population, possibly leading to surface pollution in regions of high stellar density. Data presented herein were obtained at the W. M. Keck Observatory, which

Fast accretion of the earth with a late moon-forming giant impact.

PubMed

Yu, Gang; Jacobsen, Stein B

2011-10-25

Constraints on the formation history of the Earth are critical for understanding of planet formation processes. (182)Hf-(182)W chronometry of terrestrial rocks points to accretion of Earth in approximately 30 Myr after the formation of the solar system, immediately followed by the Moon-forming giant impact (MGI). Nevertheless, some N-body simulations and (182)Hf-(182)W and (87)Rb-(87)Sr chronology of some lunar rocks have been used to argue for a later formation of the Moon at 52 to > 100 Myr. This discrepancy is often explained by metal-silicate disequilibrium during giant impacts. Here we describe a model of the (182)W isotopic evolution of the accreting Earth, including constraints from partitioning of refractory siderophile elements (Ni, Co, W, V, and Nb) during core formation, which can explain the discrepancy. Our modeling shows that the concentrations of the siderophile elements of the mantle are consistent with high-pressure metal-silicate equilibration in a terrestrial magma ocean. Our analysis shows that the timing of the MGI is inversely correlated with the time scale of the main accretion stage of the Earth. Specifically, the earliest time the MGI could have taken place right at approximately 30 Myr, corresponds to the end of main-stage accretion at approximately 30 Myr. A late MGI (> 52 Myr) requires the main stage of the Earth's accretion to be completed rapidly in < 10.7 ± 2.5 Myr. These are the two end member solutions and a continuum of solutions exists in between these extremes.

Giant Planets in Open Clusters

NASA Astrophysics Data System (ADS)

Quinn, S. N.; White, R. J.; Latham, D. W.

2015-10-01

Two decades after the discovery of 51 Peg b, more than 200 hot Jupiters have now been confirmed, but the details of their inward migration remain uncertain. While it is widely accepted that short period giant planets could not have formed in situ, several different mechanisms (e.g., Type II migration, planet-planet scattering, Kozai-Lidov cycles) may contribute to shrinking planetary orbits, and the relative importance of each is not well-constrained. Migration through the gas disk is expected to preserve circular, coplanar orbits and must occur quickly (within ˜ 10 Myr), whereas multi-body processes should initially excite eccentricities and inclinations and may take hundreds of millions of years. Subsequent evolution of the system (e.g., orbital circularization and inclination damping via tidal interaction with the host star) may obscure these differences, so observing hot Jupiters soon after migration occurs can constrain the importance of each mechanism. Fortunately, the well-characterized stars in young and adolescent open clusters (with known ages and compositions) provide natural laboratories for such studies, and recent surveys have begun to take advantage of this opportunity. We present a review of the discoveries in this emerging realm of exoplanet science, discuss the constraints they provide for giant planet formation and migration, and reflect on the future direction of the field.

Cosmic-ray ionisation of dense molecular clouds

NASA Astrophysics Data System (ADS)

Vaupre, Solenn

2015-07-01

Cosmic rays (CR) are of tremendous importance in the dynamical and chemical evolution of interstellar molecular clouds, where stars and planets form. CRs are likely accelerated in the shells of supernova remnants (SNR), thus molecular clouds nearby can be irradiated by intense fluxes of CRs. CR protons have two major effects on dense molecular clouds: 1) when they encounter the dense medium, high-energy protons (>280 MeV) create pions that decay into gamma-rays. This process makes SNR-molecular cloud associations intense GeV and/or TeV sources whose spectra mimic the CR spectrum. 2) at lower energies, CRs penetrate the cloud and ionise the gas, leading to the formation of molecular species characteristic of the presence of CRs, called tracers of the ionisation. Studying these tracers gives information on low-energy CRs that are unaccessible to any other observations. I studied the CR ionisation of molecular clouds next to three SNRs: W28, W51C and W44. These SNRs are known to be interacting with the nearby clouds, from the presence of shocked gas, OH masers and pion-decay induced gamma-ray emission. My work includes millimeter observations and chemical modeling of tracers of the ionisation in these dense molecular clouds. In these three regions, we determined an enhanced CR ionisation rate, supporting the hypothesis of an origin of the CRs in the SNR nearby. The evolution of the CR ionisation rate with the distance to the SNR brings valuable constraints on the propagation properties of low-energy CRs. The method used relies on observations of the molecular ions HCO+ and DCO+, which shows crucial limitations at high ionisation. Therefore, I investigated, both through modeling and observations, the chemical abundances of several other species to try and identity alternative tracers of the ionisation. In particular, in the W44 region, observations of N2H+ bring additional constraints on the physical conditions, volatile abundances in the cloud, and the ionisation

Radiation Hydrodynamics with GIZMO: The Disruption of Giant Molecular Clouds by Stellar Radiation Pressure

NASA Astrophysics Data System (ADS)

Khatami, David; Hopkins, Philip F.

2016-01-01

We present a numerical implementation of radiation hydrodynamics for the meshless code GIZMO. The radiation transport is treated as an anisotropic diffusion process combined with radiation pressure effects, photoionization with heating and cooling routines, and a multifrequency treatment of an arbitrary number of sources. As a first application of the method, we investigate the disruption of giant molecular clouds by stellar radiative feedback. Specifically, what fraction of the gas must a GMC convert into stars to cause self-disruption? We test a range of cloud masses and sizes with several source luminosities to probe the effects of photoheating and radiation pressure on timescales shorter than the onset of the first supernovae. Observationally, only ~1-10% of gas is converted into stars, an inefficiency that is likely the result of feedback from newly formed stars. Whether photoheating or radiation pressure dominates is dependent on the given cloud properties. For denser clouds, we expect photoheating to play a negligible role with most of the feedback driven by radiation pressure. This work explores the necessary parameters a GMC must have in order for radiation pressure to be the main disruption process.

Disruption of Giant Molecular Clouds by Massive Star Clusters

NASA Astrophysics Data System (ADS)

Harper-Clark, Elizabeth

The lifetime of a Giant Molecular Cloud (GMC) and the total mass of stars that form within it are crucial to the understanding of star formation rates across a whole galaxy. In particular, the stars within a GMC may dictate its disruption and the quenching of further star formation. Indeed, observations show that the Milky Way contains GMCs with extensive expanding bubbles while the most massive stars are still alive. Simulating entire GMCs is challenging, due to the large variety of physics that needs to be included, and the computational power required to accurately simulate a GMC over tens of millions of years. Using the radiative-magneto-hydrodynamic code Enzo, I have run many simulations of GMCs. I obtain robust results for the fraction of gas converted into stars and the lifetimes of the GMCs: (A) In simulations with no stellar outputs (or "feedback''), clusters form at a rate of 30% of GMC mass per free fall time; the GMCs were not disrupted but contained forming stars. (B) Including ionization gas pressure or radiation pressure into the simulations, both separately and together, the star formation was quenched at between 5% and 21% of the original GMC mass. The clouds were fully disrupted within two dynamical times after the first cluster formed. The radiation pressure contributed the most to the disruption of the GMC and fully quenched star formation even without ionization. (C) Simulations that included supernovae showed that they are not dynamically important to GMC disruption and have only minor effects on subsequent star formation. (D) The inclusion of a few micro Gauss magnetic field across the cloud slightly reduced the star formation rate but accelerated GMC disruption by reducing bubble shell disruption and leaking. These simulations show that new born stars quench further star formation and completely disrupt the parent GMC. The low star formation rate and the short lifetimes of GMCs shown here can explain the low star formation rate across the

Gamma-Ray Observations of the Orion Molecular Clouds with the Fermi Large Area Telescope

NASA Technical Reports Server (NTRS)

Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.;

Gamma-ray observations of the Orion Molecular Clouds with the Fermi Large Area Telescope

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

Ackermann, M.; Ajello, M.; Allafort, A.

We report on the gamma-ray observations of giant molecular clouds Orion A and B with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The gamma-ray emission in the energy band between ~100 MeV and ~100 GeV is predicted to trace the gas mass distribution in the clouds through nuclear interactions between the Galactic cosmic rays (CRs) and interstellar gas. The gamma-ray production cross-section for the nuclear interaction is known to ~10% precision which makes the LAT a powerful tool to measure the gas mass column density distribution of molecular clouds for a known CR intensity. Wemore » present here such distributions for Orion A and B, and correlate them with those of the velocity-integrated CO intensity (W CO) at a 1° × 1° pixel level. The correlation is found to be linear over a W CO range of ~10-fold when divided in three regions, suggesting penetration of nuclear CRs to most of the cloud volumes. The W CO-to-mass conversion factor, X CO, is found to be ~2.3 × 10 20 cm -2(K km s –1) –1 for the high-longitude part of Orion A (l > 212°), ~1.7 times higher than ~1.3 × 10 20 found for the rest of Orion A and B. We interpret the apparent high X CO in the high-longitude region of Orion A in the light of recent works proposing a nonlinear relation between H2 and CO densities in the diffuse molecular gas. W CO decreases faster than the H 2 column density in the region making the gas "darker" to W CO.« less

H I in Arp 72 and similarities with M51-type systems

NASA Astrophysics Data System (ADS)

Sengupta, Chandreyee; Saikia, D. J.; Dwarakanath, K. S.

2012-02-01

We present neutral hydrogen (H I) observations with the Giant Metrewave Radio Telescope (GMRT) of the interacting galaxies NGC 5996 and 5994, which make up the Arp 72 system. Arp 72 is an M51-type system and shows a complex distribution of H I tails and a bridge due to tidal interactions. H I column densities ranging from 0.8-1.8 × 1020 atoms cm-2 in the eastern tidal tail to 1.7-2 × 1021 atoms cm-2 in the bridge connecting the two galaxies are seen to be associated with star-forming regions. We discuss the morphological and kinematic similarities of Arp 72 with M51, the archetypal example of the M51-type systems, and Arp 86, another M51-type system studied with the GMRT, and suggest that a multiple passage model of Salo & Laurikainen may be preferred over the classical single passage model of Toomre & Toomre to reproduce the H I features in Arp 72 as well as in other M-51 systems depicting similar optical and H I features.

Profile of microRNA in Giant Panda Blood: A Resource for Immune-Related and Novel microRNAs.

PubMed

Yang, Mingyu; Du, Lianming; Li, Wujiao; Shen, Fujun; Fan, Zhenxin; Jian, Zuoyi; Hou, Rong; Shen, Yongmei; Yue, Bisong; Zhang, Xiuyue

2015-01-01

The giant panda (Ailuropoda melanoleuca) is one of the world's most beloved endangered mammals. Although the draft genome of this species had been assembled, little was known about the composition of its microRNAs (miRNAs) or their functional profiles. Recent studies demonstrated that changes in the expression of miRNAs are associated with immunity. In this study, miRNAs were extracted from the blood of four healthy giant pandas and sequenced by Illumina next generation sequencing technology. As determined by miRNA screening, a total of 276 conserved miRNAs and 51 novel putative miRNAs candidates were detected. After differential expression analysis, we noticed that the expressions of 7 miRNAs were significantly up-regulated in young giant pandas compared with that of adults. Moreover, 2 miRNAs were up-regulated in female giant pandas and 1 in the male individuals. Target gene prediction suggested that the miRNAs of giant panda might be relevant to the expressions of 4,602 downstream genes. Subseuqently, the predicted target genes were conducted to KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis and we found that these genes were mainly involved in host immunity, including the Ras signaling pathway, the PI3K-Akt signaling pathway, and the MAPK signaling pathway. In conclusion, our results provide the first miRNA profiles of giant panda blood, and the predicted functional analyses may open an avenue for further study of giant panda immunity.

Profile of microRNA in Giant Panda Blood: A Resource for Immune-Related and Novel microRNAs

PubMed Central

Yang, Mingyu; Du, Lianming; Li, Wujiao; Shen, Fujun; Fan, Zhenxin; Jian, Zuoyi; Hou, Rong; Shen, Yongmei; Yue, Bisong; Zhang, Xiuyue

2015-01-01

The giant panda (Ailuropoda melanoleuca) is one of the world’s most beloved endangered mammals. Although the draft genome of this species had been assembled, little was known about the composition of its microRNAs (miRNAs) or their functional profiles. Recent studies demonstrated that changes in the expression of miRNAs are associated with immunity. In this study, miRNAs were extracted from the blood of four healthy giant pandas and sequenced by Illumina next generation sequencing technology. As determined by miRNA screening, a total of 276 conserved miRNAs and 51 novel putative miRNAs candidates were detected. After differential expression analysis, we noticed that the expressions of 7 miRNAs were significantly up-regulated in young giant pandas compared with that of adults. Moreover, 2 miRNAs were up-regulated in female giant pandas and 1 in the male individuals. Target gene prediction suggested that the miRNAs of giant panda might be relevant to the expressions of 4,602 downstream genes. Subseuqently, the predicted target genes were conducted to KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis and we found that these genes were mainly involved in host immunity, including the Ras signaling pathway, the PI3K-Akt signaling pathway, and the MAPK signaling pathway. In conclusion, our results provide the first miRNA profiles of giant panda blood, and the predicted functional analyses may open an avenue for further study of giant panda immunity. PMID:26599861

STS 51-G crew photo on the flight deck

NASA Image and Video Library

1985-06-22

51G-21-011 (17-24 June 1985) --- Group portrait on flight deck of all seven STS-51G crew members. Left to right (front) are John O. Creighton, Shannon W. Lucid, Daniel C. Brandenstein; and (back row) are Sultan Salman Abdelazize Al-Saud, Steven R. Nagel, John M. Fabian and Patrick Baudry. Photo credit: NASA

IRAS observations of a large circumstellar dust shell around W Hydrae

NASA Technical Reports Server (NTRS)

Hawkins, G. W.

1990-01-01

IRAS observations at 60 and 100 microns reveal a large 30-40-arcmin (about 1-pc) diameter dust shell centered on the oxygen-rich red giant W Hya. Except for SNRs, this is the largest mass-loss envelope, in apparent diameter, known around any evolved star, including PN. W Hya's radiation field, stronger than the interstellar radiation field in the outer envelope, is sufficient to heat dust grains with IR emissivity proportional to lambda exp -1.2 to temperatures of about 40 K implied by the ratio of intensities at 60 and 100 microns.

Latitudinal exposure to DDTs, HCB, PCBs, PBDEs and DP in giant petrels (Macronectes spp.) across the Southern Ocean

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

Roscales, Jose L., E-mail: jlroscales@iqog.csic.es; González-Solís, Jacob; Zango, Laura

Studies on Persistent Organic Pollutants (POPs) in Antarctic wildlife are scarce, and usually limited to a single locality. As a result, wildlife exposure to POPs across the Southern Ocean is poorly understood. In this study, we report the differential exposure of the major southern ocean scavengers, the giant petrels, to POPs across a wide latitudinal gradient. Selected POPs (PCBs, HCB, DDTs, PBDEs) and related compounds, such as Dechlorane Plus (DP), were analyzed in plasma of southern giant petrels (Macronectes giganteus) breeding on Livingston (62°S 61°W, Antarctica), Marion (46°S 37°E, sub-Antarctic), and Gough (40°S 10°W, cool temperate) islands. Northern giant petrelsmore » (Macronectes halli) from Marion Island were also studied. Stable isotope ratios of C and N (δ{sup 13}C and δ{sup 15}N) were used as dietary tracers of the marine habitat and trophic level, respectively. Breeding locality was a major factor explaining petrel exposure to POPs compared with species and sex. Significant relationships between δ{sup 13}C values and POP burdens, at both inter- and intra-population levels, support latitudinal variations in feeding grounds as a key factor in explaining petrel pollutant burdens. Overall, pollutant levels in giant petrels decreased significantly with latitude, but the relative abundance (%) of the more volatile POPs increased towards Antarctica. DP was found at negligible levels compared with legacy POPs in Antarctic seabirds. Spatial POP patterns found in giant petrels match those predicted by global distribution models, and reinforce the hypothesis of atmospheric long-range transport as the main source of POPs in Antarctica. Our results confirm that wildlife movements out of the polar region markedly increase their exposure to POPs. Therefore, strategies for Antarctic wildlife conservation should consider spatial heterogeneity in exposure to marine pollution. Of particular relevance is the need to clarify the exposure of Antarctic

Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

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

Watson, J.D.; Siniscalco, M.

This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

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

AIP mutations in young patients with acromegaly and the Tampico Giant: the Mexican experience.

PubMed

Ramírez-Rentería, Claudia; Hernández-Ramírez, Laura C; Portocarrero-Ortiz, Lesly; Vargas, Guadalupe; Melgar, Virgilio; Espinosa, Etual; Espinosa-de-Los-Monteros, Ana Laura; Sosa, Ernesto; González, Baldomero; Zúñiga, Sergio; Unterländer, Martina; Burger, Joachim; Stals, Karen; Bussell, Anne-Marie; Ellard, Sian; Dang, Mary; Iacovazzo, Donato; Kapur, Sonal; Gabrovska, Plamena; Radian, Serban; Roncaroli, Federico; Korbonits, Márta; Mercado, Moisés

2016-08-01

Although aryl hydrocarbon receptor-interacting protein (AIP) mutations are rare in sporadic acromegaly, their prevalence among young patients is nonnegligible. The objectives of this study were to evaluate the frequency of AIP mutations in a cohort of Mexican patients with acromegaly with disease onset before the age of 30 and to search for molecular abnormalities in the AIP gene in teeth obtained from the "Tampico Giant". Peripheral blood DNA from 71 patients with acromegaly (51 females) with disease onset <30 years was analysed (median age of disease onset of 23 years) and correlated with clinical, biochemical and imaging characteristics. Sequencing was also carried out in DNA extracted from teeth of the Tampico Giant. Five patients (7 %) harboured heterozygous, germline mutations of the AIP gene. In two of them (a 9-year-old girl with gigantism and a young man with symptoms of GH excess since age 14) the c.910C>T (p.Arg304Ter), well-known truncating mutation was identified; in one of these two cases and her identical twin sister, the mutation proved to be a de novo event, since neither of their parents were found to be carriers. In the remaining three patients, new mutations were identified: a frameshift mutation (c.976_977insC, p.Gly326AfsTer), an in-frame deletion (c.872_877del, p.Val291_Leu292del) and a nonsense mutation (c.868A > T, p.Lys290Ter), which are predicted to be pathogenic based on in silico analysis. Patients with AIP mutations tended to have an earlier onset of acromegaly and harboured larger and more invasive tumours. A previously described genetic variant of unknown significance (c.869C > T, p.Ala299Val) was identified in DNA from the Tampico Giant. The prevalence of AIP mutations in young Mexican patients with acromegaly is similar to that of European cohorts. Our results support the need for genetic evaluation of patients with early onset acromegaly.

Fast accretion of the Earth with a late Moon-forming giant impact

PubMed Central

Yu, Gang; Jacobsen, Stein B.

2011-01-01

Constraints on the formation history of the Earth are critical for understanding of planet formation processes. 182Hf-182W chronometry of terrestrial rocks points to accretion of Earth in approximately 30 Myr after the formation of the solar system, immediately followed by the Moon-forming giant impact (MGI). Nevertheless, some N-body simulations and 182Hf-182W and 87Rb-87Sr chronology of some lunar rocks have been used to argue for a later formation of the Moon at 52 to > 100 Myr. This discrepancy is often explained by metal-silicate disequilibrium during giant impacts. Here we describe a model of the 182W isotopic evolution of the accreting Earth, including constraints from partitioning of refractory siderophile elements (Ni, Co, W, V, and Nb) during core formation, which can explain the discrepancy. Our modeling shows that the concentrations of the siderophile elements of the mantle are consistent with high-pressure metal-silicate equilibration in a terrestrial magma ocean. Our analysis shows that the timing of the MGI is inversely correlated with the time scale of the main accretion stage of the Earth. Specifically, the earliest time the MGI could have taken place right at approximately 30 Myr, corresponds to the end of main-stage accretion at approximately 30 Myr. A late MGI (> 52 Myr) requires the main stage of the Earth’s accretion to be completed rapidly in < 10.7 ± 2.5 Myr. These are the two end member solutions and a continuum of solutions exists in between these extremes. PMID:22006299

Emergent Properties of Giant Vesicles Formed by a Polymerization-Induced Self-Assembly (PISA) Reaction

NASA Astrophysics Data System (ADS)

Albertsen, Anders N.; Szymański, Jan K.; Pérez-Mercader, Juan

2017-01-01

Giant micrometer sized vesicles are of obvious interest to the natural sciences as well as engineering, having potential application in fields ranging from drug delivery to synthetic biology. Their formation often requires elaborate experimental techniques and attempts to obtain giant vesicles from chemical media in a one-pot fashion have so far led to much smaller nanoscale structures. Here we show that a tailored medium undergoing controlled radical polymerization is capable of forming giant polymer vesicles. Using a protocol which allows for an aqueous reaction under mild conditions, we observe the macroscale consequences of amphiphilic polymer synthesis and the resulting molecular self-assembly using fluorescence microscopy. The polymerization process is photoinitiated by blue light granting complete control of the reaction, including on the microscope stage. The self-assembly process leads to giant vesicles with radii larger than 10 microns, exhibiting several emergent properties, including periodic growth and collapse as well as phototaxis.

THE LOCATION, CLUSTERING, AND PROPAGATION OF MASSIVE STAR FORMATION IN GIANT MOLECULAR CLOUDS

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

Ochsendorf, Bram B.; Meixner, Margaret; Chastenet, Jérémy

Massive stars are key players in the evolution of galaxies, yet their formation pathway remains unclear. In this work, we use data from several galaxy-wide surveys to build an unbiased data set of ∼600 massive young stellar objects, ∼200 giant molecular clouds (GMCs), and ∼100 young (<10 Myr) optical stellar clusters (SCs) in the Large Magellanic Cloud. We employ this data to quantitatively study the location and clustering of massive star formation and its relation to the internal structure of GMCs. We reveal that massive stars do not typically form at the highest column densities nor centers of their parentmore » GMCs at the ∼6 pc resolution of our observations. Massive star formation clusters over multiple generations and on size scales much smaller than the size of the parent GMC. We find that massive star formation is significantly boosted in clouds near SCs. However, whether a cloud is associated with an SC does not depend on either the cloud’s mass or global surface density. These results reveal a connection between different generations of massive stars on timescales up to 10 Myr. We compare our work with Galactic studies and discuss our findings in terms of GMC collapse, triggered star formation, and a potential dichotomy between low- and high-mass star formation.« less

1. Historic American Buildings Survey E. W. Russell, Photographer, October ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Historic American Buildings Survey E. W. Russell, Photographer, October 17, 1935 51-69 Government St. BLOCK OF BUILDINGS ON GOVERNMENT ST. (S. SIDE) BETWEEN WATER AND ROYAL STREETS - 51-69 Government Street (Commercial Building), Mobile, Mobile County, AL

Giant pandas are not an evolutionary cul-de-sac: evidence from multidisciplinary research.

PubMed

Wei, Fuwen; Hu, Yibo; Yan, Li; Nie, Yonggang; Wu, Qi; Zhang, Zejun

2015-01-01

The giant panda (Ailuropoda melanoleuca) is one of the world's most endangered mammals and remains threatened by environmental and anthropogenic pressure. It is commonly argued that giant pandas are an evolutionary cul-de-sac because of their specialized bamboo diet, phylogenetic changes in body size, small population, low genetic diversity, and low reproductive rate. This notion is incorrect, arose from a poor understanding or appreciation of giant panda biology, and is in need of correction. In this review, we summarize research across morphology, ecology, and genetics to dispel the idea, once and for all, that giant pandas are evolutionary dead-end. The latest and most advanced research shows that giant pandas are successful animals highly adapted to a specialized bamboo diet via morphological, ecological, and genetic adaptations and coadaptation of gut microbiota. We also debunk misconceptions around population size, population growth rate, and genetic variation. During their evolutionary history spanning 8 My, giant pandas have survived diet specialization, massive bamboo flowering and die off, and rapid climate oscillations. Now, they are suffering from enormous human interference. Fortunately, continued conservation effort is greatly reducing impacts from anthropogenic interference and allowing giant panda populations and habitat to recover. Previous ideas of a giant panda evolutionary cul-de-sac resulted from an unsystematic and unsophisticated understanding of their biology and it is time to shed this baggage and focus on the survival and maintenance of this high-profile species. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

Over 0.5 MW green laser from sub-nanosecond giant pulsed microchip laser

NASA Astrophysics Data System (ADS)

Zheng, Lihe; Taira, Takunori

2016-03-01

A sub-nanosecond green laser with laser head sized 35 × 35 × 35 mm3 was developed from a giant pulsed microchip laser for laser processing on organic superconducting transistor with a flexible substrate. A composite monolithic Y3Al5O12 (YAG) /Nd:YAG/Cr4+:YAG/YAG crystal was designed for generating giant pulsed 1064 nm laser. A fibercoupled 30 W laser diode centered at 808 nm was used with pump pulse duration of 245 μs. The 532 nm green laser was obtained from a LiB3O5 (LBO) crystal with output energy of 150 μJ and pulse duration of 268 ps. The sub-nanosecond green laser is interesting for 2-D ablation patterns.

The evolution of the gut microbiota in the giant and the red pandas.

PubMed

Li, Ying; Guo, Wei; Han, Shushu; Kong, Fanli; Wang, Chengdong; Li, Desheng; Zhang, Heming; Yang, Mingyao; Xu, Huailiang; Zeng, Bo; Zhao, Jiangchao

2015-05-18

The independent dietary shift from carnivore to herbivore with over 90% being bamboo in the giant and the red pandas is of great interests to biologists. Although previous studies have shown convergent evolution of the giant and the red pandas at both morphological and molecular level, the evolution of the gut microbiota in these pandas remains largely unknown. The goal of this study was to determine whether the gut microbiota of the pandas converged due to the same diet, or diverged. We characterized the fecal microbiota from these two species by pyrosequencing the 16S V1-V3 hypervariable regions using the 454 GS FLX Titanium platform. We also included fecal samples from Asian black bears, a species phylogenetically closer to the giant panda, in our analyses. By analyzing the microbiota from these 3 species and those from other carnivores reported previously, we found the gut microbiotas of the giant pandas are distinct from those of the red pandas and clustered closer to those of the black bears. Our data suggests the divergent evolution of the gut microbiota in the pandas.

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 ...

Human-Pathogenic Enterocytozoon bieneusi in Captive Giant Pandas (Ailuropoda melanoleuca) in China.

PubMed

Li, Wei; Zhong, Zhijun; Song, Yuan; Gong, Chao; Deng, Lei; Cao, Yuying; Zhou, Ziyao; Cao, Xuefeng; Tian, Yinan; Li, Haozhou; Feng, Fan; Zhang, Yue; Wang, Chengdong; Li, Caiwu; Yang, Haidi; Huang, Xiangming; Fu, Hualin; Geng, Yi; Ren, Zhihua; Wu, Kongju; Peng, Guangneng

2018-04-26

Human and animal infections of Enterocytozoon bieneusi (E. bieneusi) have consistently been reported worldwide, garnering public attention; however, the molecular epidemiology of E. bieneusi in the giant panda remains limited. We surveyed captive giant pandas in China for the presence of E. bieneusi by using PCR and sequence analysis of the ribosomal internal transcribed spacer (ITS) revealing a 34.5% positive rate, with seven known genotypes (SC02, EpbC, CHB1, SC01, D, F, and Peru 6) and five novel genotypes (SC04, SC05, SC06, SC07, and SC08) identified. We similarly analyzed water samples, and E. bieneusi was detected in two samples, with genotype SC02 identified. Phylogenetic analysis revealed that CHB1 did not cluster with any recognized group, while the remaining genotypes belonged to group 1. The predominance of zoonotic group 1 genotypes indicates a public health threat that giant pandas could spread E. bieneusi to humans. The identification of E. bieneusi in water samples suggests giant pandas could contribute to water contamination. Effective control measures are therefore needed to minimize the contamination of the water and prevent a human microsporidiosis outbreak.

Giant Planet Formation

NASA Astrophysics Data System (ADS)

D'Angelo, G.; Durisen, R. H.; Lissauer, J. J.

2010-12-01

Gas giant planets play a fundamental role in shaping the orbital architecture of planetary systems and in affecting the delivery of volatile materials to terrestrial planets in the habitable zones. Current theories of gas giant planet formation rely on either of two mechanisms: the core accretion model and the disk instability model. In this chapter, we describe the essential principles upon which these models are built and discuss the successes and limitations of each model in explaining observational data of giant planets orbiting the Sun and other stars.

On the origin and composition of Theia: Constraints from new models of the Giant Impact

NASA Astrophysics Data System (ADS)

Meier, M. M. M.; Reufer, A.; Wieler, R.

2014-11-01

Knowing the isotopic composition of Theia, the proto-planet which collided with the Earth in the Giant Impact that formed the Moon, could provide interesting insights on the state of homogenization of the inner Solar System at the late stages of terrestrial planet formation. We use the known isotopic and modeled chemical compositions of the bulk silicate mantles of Earth and Moon and combine them with different Giant Impact models, to calculate the possible ranges of isotopic composition of Theia in O, Si, Ti, Cr, Zr and W in each model. We compare these ranges to the isotopic composition of carbonaceous chondrites, Mars, and other Solar System materials. In the absence of post-impact isotopic re-equilibration, the recently proposed high angular momentum models of the Giant Impact ("impact-fission", Cúk, M., Stewart, S.T. [2012]. Science 338, 1047; and "merger", Canup, R.M. [2012]. Science 338, 1052) allow - by a narrow margin - for a Theia similar to CI-chondrites, and Mars. The "hit-and-run" model (Reufer, A., Meier, M.M.M., Benz, W., Wieler, R. [2012]. Icarus 221, 296-299) allows for a Theia similar to enstatite-chondrites and other Earth-like materials. If the Earth and Moon inherited their different mantle FeO contents from the bulk mantles of the proto-Earth and Theia, the high angular momentum models cannot explain the observed difference. However, both the hit-and-run as well as the classical or "canonical" Giant Impact model naturally explain this difference as the consequence of a simple mixture of two mantles with different FeO. Therefore, the simplest way to reconcile the isotopic similarity, and FeO dissimilarity, of Earth and Moon is a Theia with an Earth-like isotopic composition and a higher (∼20%) mantle FeO content.

Four STS 51-G crewmembers on Discovery's middeck

NASA Image and Video Library

1985-06-17

Four STS 51-G crewmembers huddle in a corner of the Discovery's middeck area. Daniel C. Brandenstein, mission commander, assists Steven R. Nagel with the treadmill device while John O. Creighton and Shannon W. Lucid look on.

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

Discovery of a Giant Radio Halo in a New Planck Galaxy Cluster PLCKG171.9-40.7

NASA Technical Reports Server (NTRS)

Giacintucci, Simona; Kale, Ruta; Wik, Daniel R.; Venturi, Tiziana; Markevitch, Maxim

2013-01-01

We report the discovery of a giant radio halo in a new, hot, X-ray luminous galaxy cluster recently found by Planck, PLCKG171.9-40.7. The radio halo was found using Giant Metrewave Radio Telescope observations at 235 MHz and 610 MHz, and in the 1.4 GHz data from a NRAO Very Large Array Sky Survey pointing that we have reanalyzed. The diffuse radio emission is coincident with the cluster X-ray emission, has an extent of approx.1 Mpc and a radio power of approx. 5×10(exp 24)W/Hz at 1.4 GHz. Its integrated radio spectrum has a slope of alpha approx. = 1.8 between 235 MHz and 1.4 GHz, steeper than that of a typical giant halo. The analysis of the archival XMMNewton X-ray data shows that the cluster is hot (approx. 10 keV) and disturbed, consistent with X-ray selected clusters hosting radio halos. This is the first giant radio halo discovered in one of the new clusters found by Planck.

HUBBLE SPACE TELESCOPE CONSTRAINTS ON THE WINDS AND ASTROSPHERES OF RED GIANT STARS

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

Wood, Brian E.; Müller, Hans-Reinhard; Harper, Graham M., E-mail: brian.wood@nrl.navy.mil

We report on an ultraviolet spectroscopic survey of red giants observed by the Hubble Space Telescope , focusing on spectra of the Mg ii h and k lines near 2800 Å in order to study stellar chromospheric emission, winds, and astrospheric absorption. We focus on spectral types between K2 III and M5 III, a spectral type range with stars that are noncoronal, but possessing strong, chromospheric winds. We find a very tight relation between Mg ii surface flux and photospheric temperature, supporting the notion that all K2-M5 III stars are emitting at a basal flux level. Wind velocities ( Vmore » {sub w} ) are generally found to decrease with spectral type, with V {sub w} decreasing from ∼40 km s{sup −1} at K2 III to ∼20 km s{sup −1} at M5 III. We find two new detections of astrospheric absorption, for σ Pup (K5 III) and γ Eri (M1 III). This absorption signature had previously only been detected for α Tau (K5 III). For the three astrospheric detections, the temperature of the wind after the termination shock (TS) correlates with V {sub w} , but is lower than predicted by the Rankine–Hugoniot shock jump conditions, consistent with the idea that red giant TSs are radiative shocks rather than simple hydrodynamic shocks. A full hydrodynamic simulation of the γ Eri astrosphere is provided to explore this further.« less

Catalog of Dense Cores in the Orion A Giant Molecular Cloud

NASA Astrophysics Data System (ADS)

Shimajiri, Yoshito; Kitamura, Y.; Nakamura, F.; Momose, M.; Saito, M.; Tsukagoshi, T.; Hiramatsu, M.; Shimoikura, T.; Dobashi, K.; Hara, C.; Kawabe, R.

2015-03-01

We present Orion A giant molecular cloud core catalogs, which are based on a 1.1 mm map with an angular resolution of 36″ (˜0.07 pc) and C18O (J = 1-0) data with an angular resolution of 26.4″ (˜0.05 pc). We have cataloged 619 dust cores in the 1.1 mm map using the Clumpfind method. The ranges of the radius, mass, and density of these cores are estimated to be 0.01-0.20 pc, 0.6-1.2 × 102 {{M}⊙ }, and 0.3 × 104-9.2 × 106 cm-3, respectively. We have identified 235 cores from the C18O data. The ranges of the radius, velocity width, LTE mass, and density are 0.13-0.34 pc, 0.31-1.31 km s-1, 1.0-61.8 {{M}⊙ }, and (0.8-17.5) × 103 cm-3, respectively. From the comparison of the spatial distributions between the dust and C18O cores, four types of spatial relations were revealed: (1) the peak positions of the dust and C18O cores agree with each other (32.4% of the C18O cores), (2) two or more C18O cores are distributed around the peak position of one dust core (10.8% of the C18O cores), (3) 56.8% of the C18O cores are not associated with any dust cores, and (4) 69.3% of the dust cores are not associated with any C18O cores. The data sets and analysis are public. The data sets and annotation files for MIRIAD and KARMA of Tables 2 and 4 are available at the NRO star formation project web site via http://th.nao.ac.jp/MEMBER/nakamrfm/sflegacy/data.html

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.

Giant elves: Lightning-generated electromagnetic pulses in giant planets.

NASA Astrophysics Data System (ADS)

Luque Estepa, Alejandro; Dubrovin, Daria; José Gordillo-Vázquez, Francisco; Ebert, Ute; Parra-Rojas, Francisco Carlos; Yair, Yoav; Price, Colin

2015-04-01

We currently have direct optical observations of atmospheric electricity in the two giant gaseous planets of our Solar System [1-5] as well as radio signatures that are possibly generated by lightning from the two icy planets Uranus and Neptune [6,7]. On Earth, the electrical activity of the troposphere is associated with secondary electrical phenomena called Transient Luminous Events (TLEs) that occur in the mesosphere and lower ionosphere. This led some researchers to ask if similar processes may also exist in other planets, focusing first on the quasi-static coupling mechanism [8], which on Earth is responsible for halos and sprites and then including also the induction field, which is negligible in our planet but dominant in Saturn [9]. However, one can show that, according to the best available estimation for lightning parameters, in giant planets such as Saturn and Jupiter the effect of the electromagnetic pulse (EMP) dominates the effect that a lightning discharge has on the lower ionosphere above it. Using a Finite-Differences, Time-Domain (FDTD) solver for the EMP we found [10] that electrically active storms may create a localized but long-lasting layer of enhanced ionization of up to 103 cm-3 free electrons below the ionosphere, thus extending the ionosphere downward. We also estimate that the electromagnetic pulse transports 107 J to 1010 J toward the ionosphere. There emissions of light of up to 108 J would create a transient luminous event analogous to a terrestrial elve. Although these emissions are about 10 times fainter than the emissions coming from the lightning itself, it may be possible to target them for detection by filtering the appropiate wavelengths. [1] Cook, A. F., II, T. C. Duxbury, and G. E. Hunt (1979), First results on Jovian lightning, Nature, 280, 794, doi:10.1038/280794a0. [2] Little, B., C. D. Anger, A. P. Ingersoll, A. R. Vasavada, D. A. Senske, H. H. Breneman, W. J. Borucki, and The Galileo SSI Team (1999), Galileo images of

Kinematics of the Ultra-High-Velocity Gas in the Expanding Molecular Shell Adjacent to the W44 Supernova Remnant

NASA Astrophysics Data System (ADS)

Yamada, Masaya; Oka, Tomoharu; Tanaka, Kunihiko; Nomura, Mariko; Takekawa, Shunya; Iwata, Yuhei; Tokuyama, Sekito; Tanabe, Keisuke; Tsujimoto, Shiho; Furusawa, Maiko

2017-01-01

High-velocity compact cloud (HVCC) is a peculiar category of molecular clouds detected in the central molecular zone of our Galaxy (Oka et al. 1998, 2007, and 2012). They are characterized by compact appearances (d < 5 pc) and very large velocity widths (Δ V > 50 km s-1). Some of them show high CO J=3-2/J=1-0 intensity ratios (>= 1.5), indicating that they consist of dense and warm molecular gas. Dispite a number of efforts, we have not reached a comprehensive interpretation of HVCCs. Recently, we detected an extraordinaly broad velocity width feature, the `Bullet', in the molecular cloud interacting with the W44 supernova remnant. The Bullet shares essential properties with HVCCs. Because of its proximity, a close inspection of the Bullet must contribute to the understanding of HVCCs.

Giant wormholes in ghost-free bigravity theory

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

Sushkov, Sergey V.; Volkov, Mikhail S., E-mail: sergey_sushkov@mail.ru, E-mail: volkov@lmpt.univ-tours.fr

2015-06-01

We study Lorentzian wormholes in the ghost-free bigravity theory described by two metrics, g and f. Wormholes can exist if only the null energy condition is violated, which happens naturally in the bigravity theory since the graviton energy-momentum tensors do not apriori fulfill any energy conditions. As a result, the field equations admit solutions describing wormholes whose throat size is typically of the order of the inverse graviton mass. Hence, they are as large as the universe, so that in principle we might all live in a giant wormhole. The wormholes can be of two different types that we callmore » W1 and W2. The W1 wormholes interpolate between the AdS spaces and have Killing horizons shielding the throat. The Fierz-Pauli graviton mass for these solutions becomes imaginary in the AdS zone, hence the gravitons behave as tachyons, but since the Breitenlohner-Freedman bound is fulfilled, there should be no tachyon instability. For the W2 wormholes the g-geometry is globally regular and in the far field zone it becomes the AdS up to subleading terms, its throat can be traversed by timelike geodesics, while the f-geometry has a completely different structure and is not geodesically complete. There is no evidence of tachyons for these solutions, although a detailed stability analysis remains an open issue. It is possible that the solutions may admit a holographic interpretation.« less

Giant wormholes in ghost-free bigravity theory

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

Sushkov, Sergey V.; Volkov, Mikhail S.; Laboratoire de Mathématiques et Physique Théorique CNRS-UMR 7350, Université de Tours, Parc de Grandmont, 37200 Tours

2015-06-09

We study Lorentzian wormholes in the ghost-free bigravity theory described by two metrics, g and f. Wormholes can exist if only the null energy condition is violated, which happens naturally in the bigravity theory since the graviton energy-momentum tensors do not apriori fulfill any energy conditions. As a result, the field equations admit solutions describing wormholes whose throat size is typically of the order of the inverse graviton mass. Hence, they are as large as the universe, so that in principle we might all live in a giant wormhole. The wormholes can be of two different types that we callmore » W1 and W2. The W1 wormholes interpolate between the AdS spaces and have Killing horizons shielding the throat. The Fierz-Pauli graviton mass for these solutions becomes imaginary in the AdS zone, hence the gravitons behave as tachyons, but since the Breitenlohner-Freedman bound is fulfilled, there should be no tachyon instability. For the W2 wormholes the g-geometry is globally regular and in the far field zone it becomes the AdS up to subleading terms, its throat can be traversed by timelike geodesics, while the f-geometry has a completely different structure and is not geodesically complete. There is no evidence of tachyons for these solutions, although a detailed stability analysis remains an open issue. It is possible that the solutions may admit a holographic interpretation.« less

The anatomy of the Orion B giant molecular cloud: A local template for studies of nearby galaxies

NASA Astrophysics Data System (ADS)

Pety, Jérôme; Guzmán, Viviana V.; Orkisz, Jan H.; Liszt, Harvey S.; Gerin, Maryvonne; Bron, Emeric; Bardeau, Sébastien; Goicoechea, Javier R.; Gratier, Pierre; Le Petit, Franck; Levrier, François; Öberg, Karin I.; Roueff, Evelyne; Sievers, Albrecht

2017-01-01

Context. Molecular lines and line ratios are commonly used to infer properties of extra-galactic star forming regions. The new generation of millimeter receivers almost turns every observation into a line survey. Full exploitation of this technical advancement in extra-galactic study requires detailed bench-marking of available line diagnostics. Aims: We aim to develop the Orion B giant molecular cloud (GMC) as a local template for interpreting extra-galactic molecular line observations. Methods: We use the wide-band receiver at the IRAM-30 m to spatially and spectrally resolve the Orion B GMC. The observations cover almost 1 square degree at 26'' resolution with a bandwidth of 32 GHz from 84 to 116 GHz in only two tunings. Among the mapped spectral lines are the , , C18O, C17O, HCN, HNC, , C2H, HCO+, N2H+(1-0), and , , SiO, c - C3H2, CH3OH (2-1) transitions. Results: We introduce the molecular anatomy of the Orion B GMC, including relationships between line intensities and gas column density or far-UV radiation fields, and correlations between selected line and line ratios. We also obtain a dust-traced gas mass that is less than approximately one third the CO-traced mass, using the standard XCO conversion factor. The presence of over-luminous CO can be traced back to the dependence of the CO intensity on UV illumination. As a matter of fact, while most lines show some dependence on the UV radiation field, CN and C2H are the most sensitive. Moreover, dense cloud cores are almost exclusively traced by N2H+. Other traditional high-density tracers, such as HCN(1-0), are also easily detected in extended translucent regions at a typical density of 500 H2 cm-3. In general, we find no straightforward relationship between line critical density and the fraction of the line luminosity coming from dense gas regions. Conclusions: Our initial findings demonstrate that the relationships between line (ratio) intensities and environment in GMCs are more complicated than often

The evolution of the gut microbiota in the giant and the red pandas

PubMed Central

Li, Ying; Guo, Wei; Han, Shushu; Kong, Fanli; Wang, Chengdong; Li, Desheng; Zhang, Heming; Yang, Mingyao; Xu, Huailiang; Zeng, Bo; Zhao, Jiangchao

2015-01-01

The independent dietary shift from carnivore to herbivore with over 90% being bamboo in the giant and the red pandas is of great interests to biologists. Although previous studies have shown convergent evolution of the giant and the red pandas at both morphological and molecular level, the evolution of the gut microbiota in these pandas remains largely unknown. The goal of this study was to determine whether the gut microbiota of the pandas converged due to the same diet, or diverged. We characterized the fecal microbiota from these two species by pyrosequencing the 16S V1–V3 hypervariable regions using the 454 GS FLX Titanium platform. We also included fecal samples from Asian black bears, a species phylogenetically closer to the giant panda, in our analyses. By analyzing the microbiota from these 3 species and those from other carnivores reported previously, we found the gut microbiotas of the giant pandas are distinct from those of the red pandas and clustered closer to those of the black bears. Our data suggests the divergent evolution of the gut microbiota in the pandas. PMID:25985413

Formation of young massive clusters from turbulent molecular clouds

NASA Astrophysics Data System (ADS)

Fujii, Michiko; Portegies Zwart, Simon

2015-08-01

We simulate the formation and evolution of young star clusters using smoothed-particle hydrodynamics (SPH) and direct N-body methods. We start by performing SPH simulations of the giant molecular cloud with a turbulent velocity field, a mass of 10^4 to 10^6 M_sun, and a density between 17 and 1700 cm^-3. We continue the SPH simulations for a free-fall time scale, and analyze the resulting structure of the collapsed cloud. We subsequently replace a density-selected subset of SPH particles with stars. As a consequence, the local star formation efficiency exceeds 30 per cent, whereas globally only a few per cent of the gas is converted to stars. The stellar distribution is very clumpy with typically a dozen bound conglomerates that consist of 100 to 10000 stars. We continue to evolve the stars dynamically using the collisional N-body method, which accurately treats all pairwise interactions, stellar collisions and stellar evolution. We analyze the results of the N-body simulations at 2 Myr and 10 Myr. From dense massive molecular clouds, massive clusters grow via hierarchical merging of smaller clusters. The shape of the cluster mass function that originates from an individual molecular cloud is consistent with a Schechter function with a power-law slope of beta = -1.73 at 2 Myr and beta = -1.67 at 10 Myr, which fits to observed cluster mass function of the Carina region. The superposition of mass functions have a power-law slope of < -2, which fits the observed mass function of star clusters in the Milky Way, M31 and M83. We further find that the mass of the most massive cluster formed in a single molecular cloud with a mass of M_g scales with 6.1 M_g^0.51 which also agrees with recent observation in M51. The molecular clouds which can form massive clusters are much denser than those typical in the Milky Way. The velocity dispersion of such molecular clouds reaches 20 km/s and it is consistent with the relative velocity of the molecular clouds observed near NGC 3603

Black and white and read all over: the past, present and future of giant panda genetics.

PubMed

Wei, Fuwen; Hu, Yibo; Zhu, Lifeng; Bruford, Michael W; Zhan, Xiangjiang; Zhang, Lei

2012-12-01

Few species attract much more attention from the public and scientists than the giant panda (Ailuropoda melanoleuca), a popular, enigmatic but highly endangered species. The application of molecular genetics to its biology and conservation has facilitated surprising insights into the biology of giant pandas as well as the effectiveness of conservation efforts during the past decades. Here, we review the history of genetic advances in this species, from phylogeny, demographical history, genetic variation, population structure, noninvasive population census and adaptive evolution to reveal to what extent the current status of the giant panda is a reflection of its evolutionary legacy, as opposed to the influence of anthropogenic factors that have negatively impacted this species. In addition, we summarize the conservation implications of these genetic findings applied for the management of this high-profile species. Finally, on the basis of these advances and predictable future changes in genetic technology, we discuss future research directions that seem promising for giant panda biology and conservation. © 2012 Blackwell Publishing Ltd.

Bipolar nebulae and mass loss from red giant stars

NASA Technical Reports Server (NTRS)

Cohen, M.

1985-01-01

Observations of several bipolar nebulae are used to learn something of the nature of mass loss from the probable red-giant progenitors of these nebulae. Phenomena discussed are: (1) probable GL 2688's optical molecular emissions; (2) newly discovered very high velocity knots along the axis of OH 0739 - 14, which reveal evidence for mass ejections of + or 300 km/s from the M9 III star embedded in this nebula; (3) the bipolar structure of three extreme carbon stars, and the evidence for periodic mass ejection in IRC + 30219, also at high speed (about 80 km/s); and (4) the curious cool TiO-rich region above Parsamian 13, which may represent the very recent shedding of photospheric material from a cool, oxygen-rich giant. Several general key questions about bipolar nebulae that relate to the process of mass loss from their progenitor stars are raised.

Molecular cloning, overexpression, purification, and sequence analysis of the giant panda (Ailuropoda melanoleuca) ferritin light polypeptide.

PubMed

Fu, L; Hou, Y L; Ding, X; Du, Y J; Zhu, H Q; Zhang, N; Hou, W R

2016-08-30

The complementary DNA (cDNA) of the giant panda (Ailuropoda melanoleuca) ferritin light polypeptide (FTL) gene was successfully cloned using reverse transcription-polymerase chain reaction technology. We constructed a recombinant expression vector containing FTL cDNA and overexpressed it in Escherichia coli using pET28a plasmids. The expressed protein was then purified by nickel chelate affinity chromatography. The cloned cDNA fragment was 580 bp long and contained an open reading frame of 525 bp. The deduced protein sequence was composed of 175 amino acids and had an estimated molecular weight of 19.90 kDa, with an isoelectric point of 5.53. Topology prediction revealed one N-glycosylation site, two casein kinase II phosphorylation sites, one N-myristoylation site, two protein kinase C phosphorylation sites, and one cell attachment sequence. Alignment indicated that the nucleotide and deduced amino acid sequences are highly conserved across several mammals, including Homo sapiens, Cavia porcellus, Equus caballus, and Felis catus, among others. The FTL gene was readily expressed in E. coli, which gave rise to the accumulation of a polypeptide of the expected size (25.50 kDa, including an N-terminal polyhistidine tag).

A NICMOS direct imaging search for giant planets around the seven single white dwarfs in the Hyades

NASA Astrophysics Data System (ADS)

Zinnecker, Hans

2003-07-01

We propose to use the NIC1 camera on HST to search for massive giant planets around the known seven single white dwarfs in the nearby Hyades cluster at sub-arcsec separations. At an age of 625 Myr, the white dwarfs had protogenitor masses of about 3 solar masses, and massive gaseous giant planets should have formed in the massive circumstellar disks around these ex Herbig A0 stars, probably at orbital separations similar or slightly larger than that of Jupiter {5 AU} in our own solar system. Such planets would have survived the post-Main Sequence mass loss of the parent star, and would have migrated outward adiabatically by a factor 4.5, equal to the ratio of initial to final stellar mass {3Mo/0.66Mo}, due to conservation of orbital angular momentum during the mass loss {AGB and PN} phase. Thus the orbital separation NOW would be 4.5 x 5 AU = 22.5 AU, which at the distance of the Hyades {45 pc} corresponds to 0.50 arcsec. Simulations with TinyTim then show that giant planets at this separation with masses in the range 6-12 Jupiter masses and apparent J and H magnitudes in the range 20.5-23.3 mag {from Baraffe or Burrows models} can be spatially resolved around the Hyades white dwarfs. Their J and H brightnesses are known to be 15 +/- 0.5 mag, implying a median star-planet brightness ratio of 1000:1 {7.5 mag}. This combination of dynamic range and orbital separation is observable with NICMOS, by subtracting images taken at two roll angles. Therefore, the proposed near-IR diffraction-limited observations in the F110W and F160W filters promise to resolve giant planets around low-mass stars for the first time. If successful, the observations would also prove that giant planets do form around early-type stars more massive than the Sun.

Metal Hydride and Alkali Halide Opacities in Extrasolar Giant Planets and Cool Stellar Atmospheres

NASA Technical Reports Server (NTRS)

Weck, Philippe F.; Stancil, Phillip C.; Kirby, Kate; Schweitzer, Andreas; Hauschildt, Peter H.

2006-01-01

The lack of accurate and complete molecular line and continuum opacity data has been a serious limitation to developing atmospheric models of cool stars and Extrasolar Giant Planets (EGPs). We report our recent calculations of molecular opacities resulting from the presence of metal hydrides and alkali halides. The resulting data have been included in the PHOENIX stellar atmosphere code (Hauschildt & Baron 1999). The new models, calculated using spherical geometry for all gravities considered, also incorporate our latest database of nearly 670 million molecular lines, and updated equations of state.

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

Fluorine doping: a feasible solution to enhancing the conductivity of high-resistance wide bandgap Mg0.51Zn0.49O active components

NASA Astrophysics Data System (ADS)

Liu, Lishu; Mei, Zengxia; Hou, Yaonan; Liang, Huili; Azarov, Alexander; Venkatachalapathy, Vishnukanthan; Kuznetsov, Andrej; Du, Xiaolong

2015-10-01

N-type doping of high-resistance wide bandgap semiconductors, wurtzite high-Mg-content MgxZn1-xO for instance, has always been a fundamental application-motivated research issue. Herein, we report a solution to enhancing the conductivity of high-resistance Mg0.51Zn0.49O active components, which has been reliably achieved by fluorine doping via radio-frequency plasma assisted molecular beam epitaxial growth. Fluorine dopants were demonstrated to be effective donors in Mg0.51Zn0.49O single crystal film having a solar-blind 4.43 eV bandgap, with an average concentration of 1.0 × 1019 F/cm3.The dramatically increased carrier concentration (2.85 × 1017 cm-3 vs ~1014 cm-3) and decreased resistivity (129 Ω · cm vs ~106 Ω cm) indicate that the electrical properties of semi-insulating Mg0.51Zn0.49O film can be delicately regulated by F doping. Interestingly, two donor levels (17 meV and 74 meV) associated with F were revealed by temperature-dependent Hall measurements. A Schottky type metal-semiconductor-metal ultraviolet photodetector manifests a remarkably enhanced photocurrent, two orders of magnitude higher than that of the undoped counterpart. The responsivity is greatly enhanced from 0.34 mA/W to 52 mA/W under 10 V bias. The detectivity increases from 1.89 × 109 cm Hz1/2/W to 3.58 × 1010 cm Hz1/2/W under 10 V bias at room temperature.These results exhibit F doping serves as a promising pathway for improving the performance of high-Mg-content MgxZn1-xO-based devices.

Amoebae, Giant Viruses, and Virophages Make Up a Complex, Multilayered Threesome

PubMed Central

Diesend, Jan; Kruse, Janis; Hagedorn, Monica; Hammann, Christian

2018-01-01

Viral infection had not been observed for amoebae, until the Acanthamoeba polyphaga mimivirus (APMV) was discovered in 2003. APMV belongs to the nucleocytoplasmatic large DNA virus (NCLDV) family and infects not only A. polyphaga, but also other professional phagocytes. Here, we review the Megavirales to give an overview of the current members of the Mimi- and Marseilleviridae families and their structural features during amoebal infection. We summarize the different steps of their infection cycle in A. polyphaga and Acanthamoeba castellani. Furthermore, we dive into the emerging field of virophages, which parasitize upon viral factories of the Megavirales family. The discovery of virophages in 2008 and research in recent years revealed an increasingly complex network of interactions between cell, giant virus, and virophage. Virophages seem to be highly abundant in the environment and occupy the same niches as the Mimiviridae and their hosts. Establishment of metagenomic and co-culture approaches rapidly increased the number of detected virophages over the recent years. Genetic interaction of cell and virophage might constitute a potent defense machinery against giant viruses and seems to be important for survival of the infected cell during mimivirus infections. Nonetheless, the molecular events during co-infection and the interactions of cell, giant virus, and virophage have not been elucidated, yet. However, the genetic interactions of these three, suggest an intricate, multilayered network during amoebal (co-)infections. Understanding these interactions could elucidate molecular events essential for proper viral factory activity and could implicate new ways of treating viruses that form viral factories. PMID:29376032

Kinematics and Metallicity of M31 Red Giants: The Giant Southern Stream and Discovery of a Second Cold Component at R=20 kpc

NASA Astrophysics Data System (ADS)

Kalirai, Jasonjot S.; Guhathakurta, Puragra; Gilbert, Karoline M.; Reitzel, David B.; Majewski, Steven R.; Rich, R. Michael; Cooper, Michael C.

2006-04-01

We present spectroscopic observations of red giant branch (RGB) stars in the Andromeda spiral galaxy (M31), acquired with the DEIMOS instrument on the Keck II 10 m telescope. The three fields targeted in this study are in the M31 spheroid, outer disk, and giant southern stream. In this paper, we focus on the kinematics and chemical composition of RGB stars in the stream field located at a projected distance of R=20 kpc from M31's center. A mix of stellar populations is found in this field. M31 RGB stars are isolated from Milky Way dwarf star contaminants using a variety of spectral and photometric diagnostics. The radial velocity distribution of RGB stars displays a clear bimodality-a primary peak centered at v¯1=-513 km s-1 and a secondary one at v¯2=-417 km s-1-along with an underlying broad component that is presumably representative of the smooth spheroid of M31. Both peaks are found to be dynamically cold with intrinsic velocity dispersions of σ(v)~16 km s-1. The mean metallicity and metallicity dispersion of stars in the two peaks is also found to be similar: <[Fe/H]>~-0.45 and σ([Fe/H])=0.2. The observed velocity of the primary peak is consistent with that predicted by dynamical models for the stream, but there is no obvious explanation for the secondary peak. The nature of the secondary cold population is unclear: it may represent (1) tidal debris from a satellite merger event that is superimposed on, but unrelated to, the giant southern stream; (2) a wrapped around component of the giant southern stream; or (3) a warp or overdensity in M31's disk at Rdisk>50 kpc (this component is well above the outward extrapolation of the smooth exponential disk brightness profile). Data presented herein were 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

Molecular Basis for Enhancement of the Meiotic DMCI Recombinase by RAD51AP1

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

Dray, Eloise; Dunlop, Myun Hwa; Kauppi, Liisa

Homologous recombination is needed for meiotic chromosome segregation, genome maintenance, and tumor suppression. RAD51AP1 (RAD51 Associated Protein 1) has been shown to interact with and enhance the recombinase activity of RAD51. Accordingly, genetic ablation of RAD51AP1 leads to enhanced sensitivity to and also chromosome aberrations upon DNA damage, demonstrating a role for RAD51AP1 in mitotic homologous recombination. Here we show physical association of RAD51AP1 with the meiosis-specific recombinase DMC1 and a stimulatory effect of RAD51AP1 on the DMC1-mediated D-loop reaction. Mechanistic studies have revealed that RAD51AP1 enhances the ability of the DMC1 presynaptic filament to capture the duplex DNA partnermore » and to assemble the synaptic complex, in which the recombining DNA strands are homologously aligned. We also provide evidence that functional co-operation is dependent on complex formation between DMC1 and RAD51AP1, and that distinct epitopes in RAD51AP1 mediate interactions with RAD51 and DMC1. Finally, we show that RAD51AP1 is expressed in mouse testes, and that RAD51AP1 foci co-localize with a subset of DMC1 foci in spermatocytes. These results suggest that RAD51AP1 also serves an important role in meiotic homologous recombination.« less

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.

Examination of the solution behaviors of the giant inorganic-organic amphiphilic hybrids

NASA Astrophysics Data System (ADS)

Zhang, Baofang

Presently, the self-assembly behaviors of traditional small surfactants and amphiphilic block copolymers are fairly well understood. In comparison, rather little is known about the self-assembly behaviors of the giant inorganic-organic amphiphilic hybrids in solution. It remains a wide open field to explore. Giant inorganic-organic amphiphilic hybrids, consisting of nanoscale inorganic clusters and organic functional groups, represent a novel class of functional hybrid materials. They have unique physical and chemical properties and potential applications in catalysis, electronic, optics, magnetic materials, medicine and biology. Therefore, as emerging building blocks, they have promising prospects in the advanced materials. In this PhD work, several representative giant inorganic-organic amphiphilic hybrids (triangular-shaped polyoxometalate (POM)-containing inorganic/organic amphiphilic hybrids, POM-containing fluorosurfactants hybrids, POM-containing peptide hybrids POM-peptide hybrids and polyhedral oligometric silsesquioxane (POSS)-polystyrene (PS) are chosen for studying their self-assembly behaviors in solution. Based on the knowledge of the physical chemistry, colloid and polymer science, we focus on the mechanism of the self-assembly process, and the morphology control of the supramolecular structures through the internal and external conditions, such as the composition of the giant amphiphilies, molecular architectures, solvent nature, temperature, concentration, and extrally added salts. It is found that the counterion-meditated interactions dominate the self-assembly of triangular-shaped hybrids in acetone/water mixed solutions, due to the highly dominant hydrophilic portions; the solvent-swelling effect, instead of the charge effect, dominates the whole self-assembly process of the POM-containing fluorosurfactants; the analogy between small surfactants and giant amphiphiles POSS-PS allows a rough assessment of the possible morphologies of the

Exoplanet Reflections: the light from 51 Peg b

NASA Astrophysics Data System (ADS)

Martins, J. H. C.; Santos, N.; Figueira, P.; Melo, C.

2015-10-01

The direct detection of reflected light from an exoplanet is, even in the most favourable cases, a herculean task, close to the detection limit of current observing facilities. To surpass this problem, we made used of a technique (Martins et al. 2013, MNRAS, 436, 1215) that uses the power of the Cross Correlation Function to recover the minute reflected signal from 51 Pegasi b with a 3-σ+ significance. This allowed us to conclude that this prototypical hot-Jupiter is most likely a highly inflated planet with a high albedo. These results were presented in the OHP2015: Twenty years of giant exoplanets conference and published in Martins et al. 2015, A&A, 576, A134.

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

Telocytes in pancreas of the Chinese giant salamander (Andrias davidianus).

PubMed

Zhang, Hui; Yu, Pengcheng; Zhong, Shengwei; Ge, Tingting; Peng, Shasha; Guo, Xiaoquan; Zhou, Zuohong

2016-11-01

Telocytes (TCs), novel interstitial cells, have been identified in various organs of many mammals. However, information about TCs of lower animals remains rare. Herein, pancreatic TCs of the Chinese giant salamanders (Andrias davidianus) were identified by CD34 immunohistochemistry (IHC) and transmission electron microscopy (TEM). The IHC micrographs revealed CD34 + TCs with long telopodes (Tps) that were located in the interstitium of the pancreas. CD34 + TCs/Tps were frequently observed between exocrine acinar cells and were close to blood vessels. The TEM micrographs also showed the existence of TCs in the interstitium of the pancreas. TCs had distinctive ultrastructural features, such as one to three very long and thin Tps with podoms and podomers, caveolae, dichotomous branching, neighbouring exosomes and vesicles. The Tps and exosomes were found in close proximity to exocrine acinar cells and α cells. It is suggested that TCs may play a role in the regeneration of acinar cells and α cells. In conclusion, our results demonstrated the presence of TCs in the pancreas of the Chinese giant salamander. This finding will assist us in a better understanding of TCs functions in the amphibian pancreas. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

SOS1 and PTPN11 mutations in five cases of Noonan syndrome with multiple giant cell lesions.

PubMed

Beneteau, Claire; Cavé, Hélène; Moncla, Anne; Dorison, Nathalie; Munnich, Arnold; Verloes, Alain; Leheup, Bruno

2009-10-01

We report five cases of multiple giant cell lesions in patients with typical Noonan syndrome. Such association has frequently been referred to as Noonan-like/multiple giant cell (NL/MGCL) syndrome before the molecular definition of Noonan syndrome. Two patients show mutations in PTPN11 (p.Tyr62Asp and p.Asn308Asp) and three in SOS1 (p.Arg552Ser and p.Arg552Thr). The latter are the first SOS1 mutations reported outside PTPN11 in NL/MGCL syndrome. MGCL lesions were observed in jaws ('cherubism') and joints ('pigmented villonodular synovitis'). We show through those patients that both types of MGCL are not PTPN11-specific, but rather represent a low penetrant (or perhaps overlooked) complication of the dysregulated RAS/MAPK signaling pathway. We recommend discarding NL/MGCL syndrome from the nosology, as this presentation is neither gene-nor allele-specific of Noonan syndrome; these patients should be described as Noonan syndrome with MGCL (of the mandible, the long bone...). The term cherubism should be used only when multiple giant cell lesions occur without any other clinical and molecular evidence of Noonan syndrome, with or without mutations of the SH3BP2 gene.

Tailed giant Tupanvirus possesses the most complete translational apparatus of the known virosphere.

PubMed

Abrahão, Jônatas; Silva, Lorena; Silva, Ludmila Santos; Khalil, Jacques Yaacoub Bou; Rodrigues, Rodrigo; Arantes, Thalita; Assis, Felipe; Boratto, Paulo; Andrade, Miguel; Kroon, Erna Geessien; Ribeiro, Bergmann; Bergier, Ivan; Seligmann, Herve; Ghigo, Eric; Colson, Philippe; Levasseur, Anthony; Kroemer, Guido; Raoult, Didier; La Scola, Bernard

2018-02-27

Here we report the discovery of two Tupanvirus strains, the longest tailed Mimiviridae members isolated in amoebae. Their genomes are 1.44-1.51 Mb linear double-strand DNA coding for 1276-1425 predicted proteins. Tupanviruses share the same ancestors with mimivirus lineages and these giant viruses present the largest translational apparatus within the known virosphere, with up to 70 tRNA, 20 aaRS, 11 factors for all translation steps, and factors related to tRNA/mRNA maturation and ribosome protein modification. Moreover, two sequences with significant similarity to intronic regions of 18 S rRNA genes are encoded by the tupanviruses and highly expressed. In this translation-associated gene set, only the ribosome is lacking. At high multiplicity of infections, tupanvirus is also cytotoxic and causes a severe shutdown of ribosomal RNA and a progressive degradation of the nucleus in host and non-host cells. The analysis of tupanviruses constitutes a new step toward understanding the evolution of giant viruses.

Novae in External Galaxies: M51, M87, and M101

NASA Astrophysics Data System (ADS)

Shafter, A. W.; Ciardullo, R.; Pritchet, C. J.

2000-02-01

As part of a program to determine the stellar population of novae, we have conducted a multiepoch Hα survey of the galaxies M51, M87, and M101. A total of nine and 12 novae were detected in the spiral galaxies M51 and M101, respectively, during four epochs of observation, and two epochs of observation yielded a total of nine novae in the giant elliptical galaxy M87. After correcting for the effective survey time and for the fraction of luminosity sampled, we find global nova rates of 18+/-7, 91+/-34, and 12+/-4 novae per year for M51, M87, and M101, respectively. After normalizing to the total K-band luminosity of each galaxy, we estimate luminosity-specific nova rates for M51, M87, and M101 of 1.09+/-0.47, 2.30+/-0.99, and 0.97+/-0.38 novae per year per 1010 solar luminosities in K. When we compare these data with measured values for the luminosity-specific nova rates of other galaxies, we find no compelling evidence for a significant variation with Hubble type. Possible ramifications of this result are discussed within the context of current theoretical models for nova production in galaxies.

Kuiper Prize: Giant Planet Atmospheres

NASA Astrophysics Data System (ADS)

Ingersoll, Andrew P.

2007-10-01

The study of giant planet atmospheres is near and dear to me, for several reasons. First, the giant planets are photogenic; the colored clouds are great tracers, and one can make fantastic movies of the atmosphere in motion. Second, the giant planets challenge us with storms that last for hundreds of years and winds that blow faster the farther you go from the sun. Third, they remind us of Earth with their hurricanes, auroras, and lightning, but they also are the link to the 200 giant planets that have been discovered around other stars. This talk will cover the past, present, and future (one hopes) of giant planet research. I will review the surprises of the Voyager and Galileo eras, and will discuss what we are learning now from the Cassini orbiter. I will review the prospects for answering the outstanding questions like: Where's the water? What is providing the colors of the clouds? How deep do the features extend? Where do the winds get their energy? What is the role of the magnetic field? Finally, I will briefly discuss how extrasolar giant planets compare with objects in our own solar system.

DETERMINING AGES OF APOGEE GIANTS WITH KNOWN DISTANCES

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

Feuillet, Diane K.; Holtzman, Jon; Bovy, Jo

2016-01-20

We present a sample of 705 local giant stars observed using the New Mexico State University 1 m telescope with the Sloan Digital Sky Survey-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, for which we estimate stellar ages and the local star formation history (SFH). The high-resolution (R ∼ 22,500), near infrared (1.51–1.7 μm) APOGEE spectra provide measurements of stellar atmospheric parameters (temperature, surface gravity, [M/H], and [α/M]). Due to the smaller uncertainties in surface gravity possible with high-resolution spectra and accurate Hipparcos distance measurements, we are able to calculate the stellar masses to within 30%. For giants, the relativelymore » rapid evolution up the red giant branch allows the age to be constrained by the mass. We examine methods of estimating age using both the mass–age relation directly and a Bayesian isochrone matching of measured parameters, assuming a constant SFH. To improve the SFH prior, we use a hierarchical modeling approach to constrain the parameters of the model SFH using the age probability distribution functions of the data. The results of an α-dependent Gaussian SFH model show a clear age–[α/M] relation at all ages. Using this SFH model as the prior for an empirical Bayesian analysis, we determine ages for individual stars. The resulting age–metallicity relation is flat, with a slight decrease in [M/H] at the oldest ages and a ∼0.5 dex spread in metallicity across most ages. For stars with ages ≲1 Gyr we find a smaller spread, consistent with radial migration having a smaller effect on these young stars than on the older stars.« less

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

Convection and Dynamo Action in Ice Giant Dynamo Models with Electrical Conductivity Stratification

NASA Astrophysics Data System (ADS)

Soderlund, K. M.; Featherstone, N. A.; Heimpel, M. H.; Aurnou, J. M.

2017-12-01

Uranus and Neptune are relatively unexplored, yet critical for understanding the physical and chemical processes that control the behavior and evolution of giant planets. Because their multipolar magnetic fields, three-jet zonal winds, and extreme energy balances are distinct from other planets in our Solar System, the ice giants provide a unique opportunity to test hypotheses for internal dynamics and magnetic field generation. While it is generally agreed that dynamo action in the ionic ocean generates their magnetic fields, the mechanisms that control the morphology, strength, and evolution of the dynamos - which are likely distinct from those in the gas giants and terrestrial planets - are not well understood. We hypothesize that the dynamos and zonal winds are dynamically coupled and argue that their characteristics are a consequence of quasi-three-dimensional turbulence in their interiors. Here, we will present new dynamo simulations with an inner electrically conducting region and outer electrically insulating layer to self-consistently couple the ionic oceans and molecular envelopes of these planets. For each simulation, the magnetic field morphology and amplitude, zonal flow profile, and internal heat flux pattern will be compared against corresponding observations of Uranus and Neptune. We will also highlight how these simulations will both contribute to and benefit from a future ice giant mission.

Influence of the R823W mutation on the interaction of the ANKS6-ANKS3: insights from molecular dynamics simulation and free energy analysis.

PubMed

Kan, Wei; Fang, Fengqin; Chen, Lin; Wang, Ruige; Deng, Qigang

2016-05-01

The sterile alpha motif (SAM) domain of the protein ANKS6, a protein-protein interaction domain, is responsible for autosomal dominant polycystic kidney disease. Although the disease is the result of the R823W point mutation in the SAM domain of the protein ANKS6, the molecular details are still unclear. We applied molecular dynamics simulations, the principal component analysis, and the molecular mechanics Poisson-Boltzmann surface area binding free energy calculation to explore the structural and dynamic effects of the R823W point mutation on the complex ANKS6-ANKS3 (PDB ID: 4NL9) in comparison to the wild proteins. The energetic analysis presents that the wild type has a more stable structure than the mutant. The R823W point mutation not only disrupts the structure of the ANKS6 SAM domain but also negatively affects the interaction of the ANKS6-ANKS3. These results further clarify the previous experiments to understand the ANKS6-ANKS3 interaction comprehensively. In summary, this study would provide useful suggestions to understand the interaction of these proteins and their fatal action on mediating kidney function.

Fluid helium at conditions of giant planetary interiors

PubMed Central

Stixrude, Lars; Jeanloz, Raymond

2008-01-01

As the second most-abundant chemical element in the universe, helium makes up a large fraction of giant gaseous planets, including Jupiter, Saturn, and most extrasolar planets discovered to date. Using first-principles molecular dynamics simulations, we find that fluid helium undergoes temperature-induced metallization at high pressures. The electronic energy gap (band gap) closes at 20,000 K at a density half that of zero-temperature metallization, resulting in electrical conductivities greater than the minimum metallic value. Gap closure is achieved by a broadening of the valence band via increased s–p hydridization with increasing temperature, and this influences the equation of state: The Grüneisen parameter, which determines the adiabatic temperature–depth gradient inside a planet, changes only modestly, decreasing with compression up to the high-temperature metallization and then increasing upon further compression. The change in electronic structure of He at elevated pressures and temperatures has important implications for the miscibility of helium in hydrogen and for understanding the thermal histories of giant planets.

On the Composition of Young, Directly Imaged Giant Planets

NASA Technical Reports Server (NTRS)

Moses, J. I.; Marley, M. S.; Zahnle, K.; Line, M. R.; Fortney, J. J.; Barman, T. S.; Visscher, C.; Lewis, N. K.; Wolff, M. J.

2016-01-01

The past decade has seen significant progress on the direct detection and characterization of young, self-luminous giant planets at wide orbital separations from their host stars. Some of these planets show evidence for disequilibrium processes like transport-induced quenching in their atmospheres; photochemistry may also be important, despite the typically large orbital distances. Disequilibrium chemical processes such as these can alter the expected composition, spectral behavior, thermal structure, and cooling history of the planets, and can potentially confuse determinations of bulk elemental ratios, which provide important insights into planet-formation mechanisms. Using a thermo/photochemical kinetics and transport model, we investigate the extent to which disequilibrium chemical processes affect the composition and spectra of directly imaged giant exoplanets. Results for specific "young Jupiters" such as HR 8799 b and c and 51 Eri b are presented, as are general trends as a function of planetary effective temperature, surface gravity, incident ultraviolet flux, and strength of deep atmospheric convection. We find that quenching is very important on young Jupiters, leading to CO/CH4 and N2/NH3 ratios much greater than; and H2O mixing ratios a factor of a few less than chemical equilibrium predictions. Photochemistry can also be important on such planets, with CO2 and HCN being key photochemical products. Carbon dioxide becomes a particularly major constituent when stratospheric temperatures are low and recycling of water following H2O photolysis becomes stifled. Young Jupiters with effective temperatures less than 700 degrees Kelvin are in a particularly interesting photochemical regime that differs from both transiting hot Jupiters and our own solar-system giant planets.

51 Eridani and GJ 3305: A 10-15 Myr old Binary Star System at 30 Parsecs

NASA Astrophysics Data System (ADS)

Feigelson, E. D.; Lawson, W. A.; Stark, M.; Townsley, L.; Garmire, G. P.

2006-03-01

Following the suggestion of Zuckerman and coworkers, we consider the evidence that 51 Eri (spectral type F0) and GJ 3305 (M0), historically classified as unrelated main-sequence stars in the solar neighborhood, are instead a wide physical binary system and members of the young β Pic moving group (BPMG). The BPMG is the nearest (d<~50 pc) of several groups of young stars with ages around 10 Myr that are kinematically convergent with the Oph-Sco-Cen association (OSCA), the nearest OB star association. Combining South African Astronomical Observatory optical photometry, Hobby-Eberly Telescope high-resolution spectroscopy, Chandra X-Ray Observatory data, and Second US Naval Observatory CCD Astrograph Catalog kinematics, we confirm with high confidence that the system is indeed extremely young. GJ 3305 itself exhibits very strong magnetic activity but has rapidly depleted most of its lithium. The 51 Eri/GJ 3305 system is the westernmost known member of the OSCA, lying 110 pc from the main subgroups. The system is similar to the BPMG wide binary HD 172555/CD -64 1208 and the HD 104237 quintet, suggesting that dynamically fragile multiple systems can survive the turbulent environments of their natal giant molecular cloud complexes, while still having high dispersion velocities imparted. Nearby young systems such as these are excellent targets for evolved circumstellar disk and planetary studies, having stellar ages comparable to that of the late phases of planet formation.

Giant planet magnetospheres

NASA Technical Reports Server (NTRS)

Bagenal, Fran

1992-01-01

The classification of the giant planet magnetospheres into two varieties is examined: the large symmetric magnetospheres of Jupiter and Saturn and the smaller irregular ones of Uranus and Neptune. The characteristics of the plasma and the current understanding of the magnetospheric processes are considered for each planet. The energetic particle populations, radio emissions, and remote sensing of magnetospheric processes in the giant planet magneotospheres are discussed.

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.

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

The Large Marseillevirus Explores Different Entry Pathways by Forming Giant Infectious Vesicles.

PubMed

Arantes, Thalita Souza; Rodrigues, Rodrigo Araújo Lima; Dos Santos Silva, Ludmila Karen; Oliveira, Graziele Pereira; de Souza, Helton Luís; Khalil, Jacques Y B; de Oliveira, Danilo Bretas; Torres, Alice Abreu; da Silva, Luis Lamberti; Colson, Philippe; Kroon, Erna Geessien; da Fonseca, Flávio Guimarães; Bonjardim, Cláudio Antônio; La Scola, Bernard; Abrahão, Jônatas Santos

2016-06-01

Triggering the amoebal phagocytosis process is a sine qua non condition for most giant viruses to initiate their replication cycle and consequently to promote their progeny formation. It is well known that the amoebal phagocytosis process requires the recognition of particles of >500 nm, and most amoebal giant viruses meet this requirement, such as mimivirus, pandoravirus, pithovirus, and mollivirus. However, in the context of the discovery of amoebal giant viruses in the last decade, Marseillevirus marseillevirus (MsV) has drawn our attention, because despite its ability to successfully replicate in Acanthamoeba, remarkably it does not fulfill the >500-nm condition, since it presents an ∼250-nm icosahedrally shaped capsid. We deeply investigated the MsV cycle by using a set of methods, including virological, molecular, and microscopic (immunofluorescence, scanning electron microscopy, and transmission electron microscopy) assays. Our results revealed that MsV is able to form giant vesicles containing dozens to thousands of viral particles wrapped by membranes derived from amoebal endoplasmic reticulum. Remarkably, our results strongly suggested that these giant vesicles are able to stimulate amoebal phagocytosis and to trigger the MsV replication cycle by an acidification-independent process. Also, we observed that MsV entry may occur by the phagocytosis of grouped particles (without surrounding membranes) and by an endosome-stimulated pathway triggered by single particles. Taken together, not only do our data deeply describe the main features of MsV replication cycle, but this is the first time, to our knowledge, that the formation of giant infective vesicles related to a DNA virus has been described. Triggering the amoebal phagocytosis process is a sine qua non condition required by most giant viruses to initiate their replication cycle. This process requires the recognition of particles of >500 nm, and many giant viruses meet this requirement. However, MsV is

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

SMA observations of the W3(OH) complex: Dynamical differentiation between W3(H2O) and W3(OH)

NASA Astrophysics Data System (ADS)

Qin, Sheng-Li; Schilke, Peter; Wu, Jingwen; Liu, Tie; Wu, Yuefang; Sánchez-Monge, Álvaro; Liu, Ying

2016-03-01

We present Submillimeter Array observations of the HCN (3-2) and HCO+ (3-2) molecular lines towards the W3(H2O) and W3(OH) star-forming complexes. Infall and outflow motions in the W3(H2O) have been characterized by observing HCN and HCO+ transitions. High-velocity blue/red-shifted emission, tracing the outflow, show multiple knots, which might originate in episodic and precessing outflows. `Blue-peaked' line profiles indicate that gas is infalling on to the W3(H2O) dust core. The measured large mass accretion rate, 2.3 × 10-3 M⊙ yr-1, together with the small free-fall time-scale, 5 × 103 yr, suggest W3(H2O) is in an early evolutionary stage of the process of formation of high-mass stars. For the W3(OH), a two-layer model fit to the HCN and HCO+ spectral lines and Spizter/Infrared Array Camera (IRAC) images support that the W3(OH) H II region is expanding and interacting with the ambient gas, with the shocked neutral gas being expanding with an expansion time-scale of 6.4 × 103 yr. The observations suggest different kinematical time-scales and dynamical states for the W3(H2O) and W3(OH).

The 51.8 micron (0 3) line emission observed in four galactic H 2 regions

NASA Technical Reports Server (NTRS)

Melnick, G.; Gull, G. E.; Harwit, M.

1978-01-01

The (0 III) 51.8 microns line from four H II regions, M42, M17, W51 and NGC 6375A was detected. Respective line strengths are 7 x 10 to the minus 15 power, 1.0 x 10 to the minus 14 power, 2.1 x 10 to the minus 15 power and 2.6 x 10 to the minus 15 power watt cm/2. Observations are consistent with previously reported line position and place the line at 51.80 + or 0.05 micron. When combined with the 88.35 microns (0 III) reported earlier, clumping seems to be an important factor in NGC 6375A and M42 and to a lesser extent in W51 and M17. The combined data also suggest an (0 III) abundance of approximately 3 x 0.0001 sub n e' a factor of 2 greater than previously assumed.

GIANT MOLECULAR CLOUD FORMATION IN DISK GALAXIES: CHARACTERIZING SIMULATED VERSUS OBSERVED CLOUD CATALOGS

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

Benincasa, Samantha M.; Pudritz, Ralph E.; Wadsley, James

We present the results of a study of simulated giant molecular clouds (GMCs) formed in a Milky Way-type galactic disk with a flat rotation curve. This simulation, which does not include star formation or feedback, produces clouds with masses ranging between 10{sup 4} M{sub ☉} and 10{sup 7} M{sub ☉}. We compare our simulated cloud population to two observational surveys: the Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey and the BIMA All-Disk Survey of M33. An analysis of the global cloud properties as well as a comparison of Larson's scaling relations is carried out. We find that simulatedmore » cloud properties agree well with the observed cloud properties, with the closest agreement occurring between the clouds at comparable resolution in M33. Our clouds are highly filamentary—a property that derives both from their formation due to gravitational instability in the sheared galactic environment, as well as to cloud-cloud gravitational encounters. We also find that the rate at which potentially star-forming gas accumulates within dense regions—wherein n{sub thresh} ≥ 10{sup 4} cm{sup –3}—is 3% per 10 Myr, in clouds of roughly 10{sup 6} M{sub ☉}. This suggests that star formation rates in observed clouds are related to the rates at which gas can be accumulated into dense subregions within GMCs via filamentary flows. The most internally well-resolved clouds are chosen for listing in a catalog of simulated GMCs—the first of its kind. The cataloged clouds are available as an extracted data set from the global simulation.« less

The NGC 1614 interacting galaxy. Molecular gas feeding a "ring of fire"

NASA Astrophysics Data System (ADS)

König, S.; Aalto, S.; Muller, S.; Beswick, R. J.; Gallagher, J. S.

2013-05-01

Minor mergers frequently occur between giant and gas-rich low-mass galaxies and can provide significant amounts of interstellar matter to refuel star formation and power active galactic nuclei (AGN) in the giant systems. Major starbursts and/or AGN result when fresh gas is transported and compressed in the central regions of the giant galaxy. This is the situation in the starburst minor merger NGC 1614, whose molecular medium we explore at half-arcsecond angular resolution through our observations of 12CO (2-1) emission using the Submillimeter Array (SMA). We compare our 12CO (2-1) maps with optical and Paα, Hubble Space Telescope and high angular resolution radio continuum images to study the relationships between dense molecular gas and the NGC 1614 starburst region. The most intense 12CO emission occurs in a partial ring with ~230 pc radius around the center of NGC 1614, with an extension to the northwest into the dust lane that contains diffuse molecular gas. We resolve ten giant molecular associations (GMAs) in the ring, which has an integrated molecular mass of ~8 × 108 M⊙. Our interferometric observations filter out a large part of the 12CO (1-0) emission mapped at shorter spacings, indicating that most of the molecular gas is diffuse and that GMAs only exist near and within the circumnuclear ring. The molecular ring is uneven with most of the mass on the western side, which also contains GMAs extending into a pronounced tidal dust lane. The spatial and kinematic patterns in our data suggest that the northwest extension of the ring is a cosmic umbilical cord that is feeding molecular gas associated with the dust lane and tidal debris into the nuclear ring, which contains the bulk of the starburst activity. The astrophysical process for producing a ring structure for the final resting place of accreted gas in NGC 1614 is not fully understood, but the presence of numerous GMAs suggests an orbit-crowding or resonance phenomenon. There is some evidence that

Magnetar Giant Flares in Multipolar Magnetic Fields. III. Multipolar Magnetic Field Structure Variations

NASA Astrophysics Data System (ADS)

Yao, Guang-Rui; Huang, Lei; Yu, Cong; Shen, Zhi-Qiang

2018-02-01

We have analyzed the multipolar magnetic field structure variation at neutron star surface by means of the catastrophic eruption model and find that the variation of the geometry of multipolar fields on the magnetar surface could result in the catastrophic rearrangement of the magnetosphere, which provides certain physical mechanism for the outburst of giant flares. The magnetospheric model we adopted consists of two assumptions: (1) a helically twisted flux rope is suspended in an ideal force-free magnetosphere around the magnetar, and (2) a current sheet emerges during the flux rope evolution. Magnetic energy accumulates during the flux rope’s gradual evolution along with the variation of magnetar surface magnetic structure before the eruption. The two typical behaviors, either state transition or catastrophic escape, would take place once the flux rope loses equilibrium; thus, tremendous accumulated energy is radiated. We have investigated the equilibrium state of the flux rope and the energy release affected by different multipolar structures and find structures that could trigger violent eruption and provide the radiation approximately 0.5% of the total magnetic energy during the giant flare outburst. Our results provide certain multipolar structures of the neutron star’s magnetic field with an energy release percentage 0.42% in the state transition and 0.51% in the catastrophic escape case, which are sufficient for the previously reported energy release from SGR 1806–20 giant flares.

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

The origins of the giant pill-millipedes from Madagascar (Diplopoda: Sphaerotheriida: Arthrosphaeridae).

PubMed

Wesener, Thomas; Raupach, Michael J; Sierwald, Petra

2010-12-01

Giant pill-millipedes (order Sphaerotheriida) are large-bodied millipedes without poison glands which can roll-up into a complete ball. Their disconnected area of distribution spanning South Africa, Madagascar, India, SE Asia, Australia and New Zealand makes them interesting model organisms for biogeographic studies. The here presented phylogeny is based on a molecular dataset covering all areas of distribution with a special focus on Madagascar, where some species of giant pill-millipedes show island gigantism, reaching the size of a baseball. For our study, two mitochondrial genes (partial 16S rRNA and COI) as well as the complete nuclear 18S rDNA were sequenced. While many recent vertebrate studies hint that the ancestors of the recent Malagasy fauna crossed the >350 km wide Mozambique Channel several times, no such crossing was discovered in the Sphaerotheriida. For the first time in a molecular phylogenetic study of soil arthropods, a Madagascar-India group, the family Arthrosphaeridae, is recovered, hinting to a Gondwanan origin of the Sphaerotheriida. The Malagasy-Indian family Arthrosphaeridae forms a monophyletic, statistically well-supported group in all obtained trees. The giant pill-millipedes from Madagascar are paraphyletic because the Malagasy genus Sphaeromimus is the sister-taxon of the Indian Arthrosphaera. In Sphaeromimus, an ecotone shift occurred only once: the spiny forest species Sphaeromimus musicus forms the sister-clade to the species collected in rainforests and littoral rainforests. The two species of the Malagasy genus Zoosphaerium which express island gigantism form a monophyletic group in some trees, but these trees lack good statistical support. Deeper nodes inside the Sphaerotheriida, like the position of the Australian genera Procyliosoma and Epicyliosoma, the Southeast Asian family Zephroniidae and the South African genus Sphaerotherium could not be resolved. This study is the first genetic study inside the order Sphaerotheriida

Simple many-body based screening mixing ansatz for improvement of G W /Bethe-Salpeter equation excitation energies of molecular systems

NASA Astrophysics Data System (ADS)

Ziaei, Vafa; Bredow, Thomas

2017-11-01

We propose a simple many-body based screening mixing strategy to considerably enhance the performance of the Bethe-Salpeter equation (BSE) approach for prediction of excitation energies of molecular systems. This strategy enables us to closely reproduce results of highly correlated equation of motion coupled cluster singles and doubles (EOM-CCSD) through optimal use of cancellation effects. We start from the Hartree-Fock (HF) reference state and take advantage of local density approximation (LDA) based random phase approximation (RPA) screening, denoted as W0-RPA@LDA with W0 as the dynamically screened interaction built upon LDA wave functions and energies. We further use this W0-RPA@LDA screening as an initial screening guess for calculation of quasiparticle energies in the framework of G0W0 @HF. The W0-RPA@LDA screening is further injected into the BSE. By applying such an approach on a set of 22 molecules for which the traditional G W /BSE approaches fail, we observe good agreement with respect to EOM-CCSD references. The reason for the observed good accuracy of this mixing ansatz (scheme A) lies in an optimal damping of HF exchange effect through the W0-RPA@LDA strong screening, leading to substantial decrease of typically overestimated HF electronic gap, and hence to better excitation energies. Further, we present a second multiscreening ansatz (scheme B), which is similar to scheme A with the exception that now the W0-RPA@HF screening is used in the BSE in order to further improve the overestimated excitation energies of carbonyl sulfide (COS) and disilane (Si2H6 ). The reason for improvement of the excitation energies in scheme B lies in the fact that W0-RPA@HF screening is less effective (and weaker than W0-RPA@LDA), which gives rise to stronger electron-hole effects in the BSE.

12 CFR 223.51 - What is the market terms requirement of section 23B?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 3 2010-01-01 2010-01-01 false What is the market terms requirement of section 23B? 223.51 Section 223.51 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM TRANSACTIONS BETWEEN MEMBER BANKS AND THEIR AFFILIATES (REGULATION W...

Angular-momentum couplings in ultra-long-range giant dipole molecules

NASA Astrophysics Data System (ADS)

Stielow, Thomas; Scheel, Stefan; Kurz, Markus

2018-02-01

In this article we extend the theory of ultra-long-range giant dipole molecules, formed by an atom in a giant dipole state and a ground-state alkali-metal atom, by angular-momentum couplings known from recent works on Rydberg molecules. In addition to s -wave scattering, the next higher order of p -wave scattering in the Fermi pseudopotential describing the binding mechanism is considered. Furthermore, the singlet and triplet channels of the scattering interaction as well as angular-momentum couplings such as hyperfine interaction and Zeeman interactions are included. Within the framework of Born-Oppenheimer theory, potential energy surfaces are calculated in both first-order perturbation theory and exact diagonalization. Besides the known pure triplet states, mixed-spin character states are obtained, opening up a whole new landscape of molecular potentials. We determine exact binding energies and wave functions of the nuclear rotational and vibrational motion numerically from the various potential energy surfaces.

A molecular gas ridge offset from the dust lane in a spiral arm of M83

NASA Technical Reports Server (NTRS)

Lord, Steven D.; Kenney, Jeffrey D. P.

1991-01-01

A high-resolution interferometric map of the CO emission on the eastern spiral arm of M83 is presented. The detected emission originates in about five unresolved components located parallel but about 300 pc downstream from the dust lane which lies along the inner edge of the spiral arm. All the CO components in the map but one are located within 130 pc of an H II region and may represent emission from locally heated gas. The lack of CO emission on the dust lane indicates that the dense molecular gas does not pile up here in M83. Remarkable differences between the molecular gas distributions in M83 and the spiral arms or M51, where CO emission peaks on the dust lane, is attributed to the difference in the strength of their density waves. The observations of M83 are consistent with the model of Elmegreen in which diffuse gas is compressed at the shock front, producing the dust lane at the inner edge of the spiral arm while dense giant molecular clouds pass through the front and form a broad distribution on the arm.

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.

Glucocorticoid and calcitonin receptor expression in central giant cell lesions: implications for therapy.

PubMed

Nogueira, R L M; Faria, M H G; Osterne, R L V; Cavalcante, R B; Ribeiro, R A; Rabenhorst, S H B

2012-08-01

Central giant cell lesion is an uncommon benign jaw lesion, with uncertain aetiology, and variable clinical behaviour. Studies of molecular markers may help to understand the nature and behaviour of this lesion, and eventually may represent a target for pharmacological approaches to treatment. The aim of this study was to analyse the expression of glucocorticoid and calcitonin receptors in central giant cell lesions before and after treatment with intralesional steroid. Paraffin-embedded blocks from patients who underwent treatment with intralesional triamcinolone hexacetonide injections were stained immunohistochemically. Biological material from patients who underwent a surgical procedure after treatment were tested immunohistochemically. 18 cases (9 aggressive and 9 non-aggressive) were included. The difference in calcitonin receptor expression was not statistically significant between the aggressive and non-aggressive lesions and between the patients with a good response and those with a moderate/negative response to treatment. Glucocorticoid receptor expression in the multinucleated giant cells was higher in patients with a good response. It can be postulated that immunohistochemical staining for glucocorticoid receptors may provide a tool for selecting the therapeutic strategy. An H-score greater than 48 for glucocorticoid receptors in multinucleated giant cells predicted a good response in this study. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Giant star seismology

NASA Astrophysics Data System (ADS)

Hekker, S.; Christensen-Dalsgaard, J.

2017-06-01

The internal properties of stars in the red-giant phase undergo significant changes on relatively short timescales. Long near-uninterrupted high-precision photometric timeseries observations from dedicated space missions such as CoRoT and Kepler have provided seismic inferences of the global and internal properties of a large number of evolved stars, including red giants. These inferences are confronted with predictions from theoretical models to improve our understanding of stellar structure and evolution. Our knowledge and understanding of red giants have indeed increased tremendously using these seismic inferences, and we anticipate that more information is still hidden in the data. Unraveling this will further improve our understanding of stellar evolution. This will also have significant impact on our knowledge of the Milky Way Galaxy as well as on exo-planet host stars. The latter is important for our understanding of the formation and structure of planetary systems.

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.

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 cells around bone biomaterials: Osteoclasts or multi-nucleated giant cells?

PubMed

Miron, Richard J; Zohdi, Hamoon; Fujioka-Kobayashi, Masako; Bosshardt, Dieter D

2016-12-01

Recently accumulating evidence has put into question the role of large multinucleated giant cells (MNGCs) around bone biomaterials. While cells derived from the monocyte/macrophage lineage are one of the first cell types in contact with implanted biomaterials, it was originally thought that specifically in bone tissues, all giant cells were bone-resorbing osteoclasts whereas foreign body giant cells (FBGCs) were found associated with a connective tissue foreign body reaction resulting in fibrous encapsulation and/or material rejection. Despite the great majority of bone grafting materials routinely found with large osteoclasts, a special subclass of bone biomaterials has more recently been found surrounded by large giant cells virtually incapable of resorbing bone grafts even years after their implantation. While original hypotheses believed that a 'foreign body reaction' may be taking place, histological data retrieved from human samples years after their implantation have put these original hypotheses into question by demonstrating better and more stable long-term bone volume around certain bone grafts. Exactly how or why this 'special' subclass of giant cells is capable of maintaining long-term bone volume, or methods to scientifically distinguish them from osteoclasts remains extremely poorly studied. The aim of this review article was to gather the current available literature on giant cell markers and differences in expression patterns between osteoclasts and MNGCs utilizing 19 specific markers including an array of CD-cell surface markers. Furthermore, the concept of now distinguishing between pro-inflammatory M1-MNGCs (previously referred to as FBGCs) as well as wound-healing M2-MNGCs is introduced and discussed. This review article presents 19 specific cell-surface markers to distinguish between osteoclasts and MNGCs including an array of CD-cell surface markers. Furthermore, the concept of now distinguishing between pro-inflammatory M1-MNGCs (often

Formation of the giant planets

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.

2006-01-01

The observed properties of giant planets, models of their evolution and observations of protoplanetary disks provide constraints on the formation of gas giant planets. The four largest planets in our Solar System contain considerable quantities of hydrogen and helium, which could not have condensed into solid planetesimals within the protoplanetary disk. All three (transiting) extrasolar giant planets with well determined masses and radii also must contain substantial amounts of these light gases. Jupiter and Saturn are mostly hydrogen and helium, but have larger abundances of heavier elements than does the Sun. Neptune and Uranus are primarily composed of heavier elements. HD 149026 b, which is slightly more massive than is Saturn, appears to have comparable quantities of light gases and heavy elements. HD 209458 b and TrES-1 are primarily hydrogen and helium, but may contain supersolar abundances of heavy elements. Spacecraft flybys and observations of satellite orbits provide estimates of the gravitational moments of the giant planets in our Solar System, which in turn provide information on the internal distribution of matter within Jupiter, Saturn, Uranus and Neptune. Atmospheric thermal structure and heat flow measurements constrain the interior temperatures of planets. Internal processes may cause giant planets to become more compositionally differentiated or alternatively more homogeneous; high-pressure laboratory .experiments provide data useful for modeling these processes. The preponderance of evidence supports the core nucleated gas accretion model. According to this model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary questions regarding the core nucleated growth model is under what conditions

First measurement of the W-boson mass in run II of the Tevatron.

PubMed

Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Daronco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Denis, R St; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

2007-10-12

We present a measurement of the W-boson mass using 200 pb{-1} of data collected in pp[over ] collisions at sqrt[s]=1.96 TeV by the CDF II detector at run II of the Fermilab Tevatron. With a sample of 63 964 W-->enu candidates and 51 128 W-->munu candidates, we measure M_{W}=80 413+/-34{stat}+/-34{syst}=80,413+/-48 MeV/c;{2}. This is the most precise single measurement of the W-boson mass to date.

Giant congenital melanocytic nevus*

PubMed Central

Viana, Ana Carolina Leite; Gontijo, Bernardo; Bittencourt, Flávia Vasques

2013-01-01

Giant congenital melanocytic nevus is usually defined as a melanocytic lesion present at birth that will reach a diameter ≥ 20 cm in adulthood. Its incidence is estimated in <1:20,000 newborns. Despite its rarity, this lesion is important because it may associate with severe complications such as malignant melanoma, affect the central nervous system (neurocutaneous melanosis), and have major psychosocial impact on the patient and his family due to its unsightly appearance. Giant congenital melanocytic nevus generally presents as a brown lesion, with flat or mammilated surface, well-demarcated borders and hypertrichosis. Congenital melanocytic nevus is primarily a clinical diagnosis. However, congenital nevi are histologically distinguished from acquired nevi mainly by their larger size, the spread of the nevus cells to the deep layers of the skin and by their more varied architecture and morphology. Although giant congenital melanocytic nevus is recognized as a risk factor for the development of melanoma, the precise magnitude of this risk is still controversial. The estimated lifetime risk of developing melanoma varies from 5 to 10%. On account of these uncertainties and the size of the lesions, the management of giant congenital melanocytic nevus needs individualization. Treatment may include surgical and non-surgical procedures, psychological intervention and/or clinical follow-up, with special attention to changes in color, texture or on the surface of the lesion. The only absolute indication for surgery in giant congenital melanocytic nevus is the development of a malignant neoplasm on the lesion. PMID:24474093

Giant Piezoelectricity and High Curie Temperature in Nanostructured Alkali Niobate Lead-Free Piezoceramics through Phase Coexistence.

PubMed

Wu, Bo; Wu, Haijun; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo; Pennycook, Stephen J

2016-11-30

Because of growing environmental concerns, the development of lead-free piezoelectric materials with enhanced properties has become of great interest. Here, we report a giant piezoelectric coefficient (d 33 ) of 550 pC/N and a high Curie temperature (T C ) of 237 °C in (1-x-y)K 1-w Na w Nb 1-z Sb z O 3- xBiFeO 3- yBi 0.5 Na 0.5 ZrO 3 (KN w NS z -xBF-yBNZ) ceramics by optimizing x, y, z, and w. Atomic-resolution polarization mapping by Z-contrast imaging reveals the intimate coexistence of rhombohedral (R) and tetragonal (T) phases inside nanodomains, that is, a structural origin for the R-T phase boundary in the present KNN system. Hence, the physical origin of high piezoelectric performance can be attributed to a nearly vanishing polarization anisotropy and thus low domain wall energy, facilitating easy polarization rotation between different states under an external field.

22 CFR 51.51 - Passport fees.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Passport fees. 51.51 Section 51.51 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.51 Passport fees. The Department collects the following passport fees in the amounts prescribed in the Schedule of Fees for Consular...

22 CFR 51.51 - Passport fees.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Passport fees. 51.51 Section 51.51 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.51 Passport fees. The Department collects the following passport fees in the amounts prescribed in the Schedule of Fees for Consular...

22 CFR 51.51 - Passport fees.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Passport fees. 51.51 Section 51.51 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.51 Passport fees. The Department collects the following passport fees in the amounts prescribed in the Schedule of Fees for Consular...

22 CFR 51.51 - Passport fees.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Passport fees. 51.51 Section 51.51 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.51 Passport fees. The Department collects the following passport fees in the amounts prescribed in the Schedule of Fees for Consular...

22 CFR 51.51 - Passport fees.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Passport fees. 51.51 Section 51.51 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.51 Passport fees. The Department collects the following passport fees in the amounts prescribed in the Schedule of Fees for Consular...

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.

Hubble Space Telescope Constraints on the Winds and Astrospheres of Red Giant Stars

NASA Astrophysics Data System (ADS)

Wood, Brian E.; Müller, Hans-Reinhard; Harper, Graham M.

2016-10-01

We report on an ultraviolet spectroscopic survey of red giants observed by the Hubble Space Telescope, focusing on spectra of the Mg II h and k lines near 2800 Å in order to study stellar chromospheric emission, winds, and astrospheric absorption. We focus on spectral types between K2 III and M5 III, a spectral type range with stars that are noncoronal, but possessing strong, chromospheric winds. We find a very tight relation between Mg II surface flux and photospheric temperature, supporting the notion that all K2-M5 III stars are emitting at a basal flux level. Wind velocities (V w ) are generally found to decrease with spectral type, with V w decreasing from ˜40 km s-1 at K2 III to ˜20 km s-1 at M5 III. We find two new detections of astrospheric absorption, for σ Pup (K5 III) and γ Eri (M1 III). This absorption signature had previously only been detected for α Tau (K5 III). For the three astrospheric detections, the temperature of the wind after the termination shock (TS) correlates with V w , but is lower than predicted by the Rankine-Hugoniot shock jump conditions, consistent with the idea that red giant TSs are radiative shocks rather than simple hydrodynamic shocks. A full hydrodynamic simulation of the γ Eri astrosphere is provided to explore this further. 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 GO-13462. This paper also presents observations obtained with the Harlan J. Smith Telescope at McDonald Observatory of the University of Texas at Austin.

The evolution of giant flightless birds and novel phylogenetic relationships for extinct fowl (Aves, Galloanseres)

NASA Astrophysics Data System (ADS)

Worthy, Trevor H.; Degrange, Federico J.; Handley, Warren D.; Lee, Michael S. Y.

2017-10-01

The extinct dromornithids, gastornithids and phorusrhacids are among the most spectacular birds to have ever lived, with some giants exceeding 500 kg. The affinities and evolution of these and other related extinct birds remain contentious, with previous phylogenetic analyses being affected by widespread convergence and limited taxon sampling. We address these problems using both parsimony and tip-dated Bayesian approaches on an expansive taxon set that includes all key extinct flightless and flighted (e.g. Vegavis and lithornithids) forms, an extensive array of extant fowl (Galloanseres), representative Neoaves and palaeognaths. The Paleogene volant Lithornithidae are recovered as stem palaeognaths in the Bayesian analyses. The Galloanseres comprise four clades inferred to have diverged in the Late Cretaceous on Gondwana. In addition to Anseriformes and Galliformes, we recognize a robust new clade (Gastornithiformes) for the giant flightless Dromornithidae (Australia) and Gastornithidae (Eurasia, North America). This clade exhibits parallels to ratite palaeognaths in that flight presumably was lost and giant size attained multiple times. A fourth clade is represented by the Cretaceous Vegavis (Antarctica), which was strongly excluded from Anseriformes; thus, a crucial molecular calibration point needs to be reconsidered. The presbyornithids Wilaru (Australia) and Presbyornis (Northern Hemisphere) are robustly found to be the sister group to Anatoidea (Anseranatidae + Anatidae), a relatively more basal position than hitherto recognized. South America's largest bird, Brontornis, is not a galloansere, but a member of Neoaves related to Cariamiformes; therefore, giant Galloanseres remain unknown from this continent. Trait analyses showed that while gigantism and flightlessness evolved repeatedly in groups, diet is constrained by phylogeny: all giant Galloanseres and palaeognaths are herbivores or mainly herbivorous, and giant neoavians are zoophagous or omnivorous.

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.

Systematic error of the Gaia DR1 TGAS parallaxes from data for the red giant clump

NASA Astrophysics Data System (ADS)

Gontcharov, G. A.

2017-08-01

Based on the Gaia DR1 TGAS parallaxes and photometry from the Tycho-2, Gaia, 2MASS, andWISE catalogues, we have produced a sample of 100 000 clump red giants within 800 pc of the Sun. The systematic variations of the mode of their absolute magnitude as a function of the distance, magnitude, and other parameters have been analyzed. We show that these variations reach 0.7 mag and cannot be explained by variations in the interstellar extinction or intrinsic properties of stars and by selection. The only explanation seems to be a systematic error of the Gaia DR1 TGAS parallax dependent on the square of the observed distance in kpc: 0.18 R 2 mas. Allowance for this error reduces significantly the systematic dependences of the absolute magnitude mode on all parameters. This error reaches 0.1 mas within 800 pc of the Sun and allows an upper limit for the accuracy of the TGAS parallaxes to be estimated as 0.2 mas. A careful allowance for such errors is needed to use clump red giants as "standard candles." This eliminates all discrepancies between the theoretical and empirical estimates of the characteristics of these stars and allows us to obtain the first estimates of the modes of their absolute magnitudes from the Gaia parallaxes: mode( M H ) = -1.49 m ± 0.04 m , mode( M Ks ) = -1.63 m ± 0.03 m , mode( M W1) = -1.67 m ± 0.05 m mode( M W2) = -1.67 m ± 0.05 m , mode( M W3) = -1.66 m ± 0.02 m , mode( M W4) = -1.73 m ± 0.03 m , as well as the corresponding estimates of their de-reddened colors.

The Wolf-Rayet star population in the most massive giant H II regions of M33

NASA Technical Reports Server (NTRS)

Drissen, Laurent; Moffat, Anthony F. J.; Shara, Michael M.

1990-01-01

Narrow-band images of NGC 604, NGC 595, and NGC 592, the most massive giant H II regions (GHRs) in M33 have been obtained, in order to study their Wolf-Rayet content. These images reveal the presence of nine candidates in NGC 604 (seven WN, two WC), 10 in NGC 595 (nine WN, one WC), and two in NGC 592 (two WN). Precise positions and estimated magnitudes are given for the candidates, half of which have so far been confirmed spectroscopically as genuine W-R stars. The flux in the emission lines of all candidates is comparable to that of normal Galactic W-R stars of similar subtype. A few of the putative superluminous W-R stars are shown to be close visual double or multiple stars; their newly estimated luminosities are now more compatible with those of normal W-R stars. NGC 595 seems to be overabundant in W-R stars for its mass compared to other GHRs, while NGC 604 is normal. Factors influencing the W-R/O number ratio in GHRs are discussed: metallicity and age appear to be the most important.

Tests of the Giant Impact Hypothesis

NASA Technical Reports Server (NTRS)

Jones, J. H.

1998-01-01

The giant impact hypothesis has gained popularity as a means of explaining a volatile-depleted Moon that still has a chemical affinity to the Earth. As Taylor's Axiom decrees, the best models of lunar origin are testable, but this is difficult with the giant impact model. The energy associated with the impact would be sufficient to totally melt and partially vaporize the Earth. And this means that there should he no geological vestige of Barber times. Accordingly, it is important to devise tests that may be used to evaluate the giant impact hypothesis. Three such tests are discussed here. None of these is supportive of the giant impact model, but neither do they disprove it.

The Anatomy of the Perseus Spiral Arm: 12 CO and IRAS Imaging Observations of the W3-W4-W5 Cloud Complex

NASA Technical Reports Server (NTRS)

Heyer, Mark H.; Terebey, S.

1998-01-01

Panoramic images of 12CO J = 1-0 and thermal dust emissions from the W3-W4-W5 region of the outer Galaxy are presented. These data and recently published H I 21 cm line emission images provide an approximate 1' resolution perspective to the dynamics and thermal energy content of the interstellar gas and dust components contained within a 9 deg. arc of the Perseus spiral arm. We tabulate the molecular properties of 1560 clouds identified as closed surfaces within the l-b-v CO data cube at a threshold of 0.9 K T* (sub R). Relative surface densities of the molecular (28:1) and atomic (2.5:1) gas components determined within the arm and interarm velocity intervals demonstrate that the gas component that enters the spiral arm is predominantly atomic. Molecular clouds must necessarily condense from the compressed atomic material that enters the spiral arm and are likely short lived within the interarm regions. From the distribution of centroid velocities of clouds, we determine a random cloud-to-cloud velocity dispersion of 4 km s (exp. -1) over the width of the spiral arm but find no clear evidence within the molecular gas for streaming motions induced by the spiral potential. The far-infrared images are analyzed with the CO J = 1-0 and H I 21 cm line emission. The enhanced UV (Ultraviolet) radiation field from members of the Cas OB6 association and embedded newborn stars provide a significant source of heating to the extended dust component within the Perseus arm relative to the quiescent cirrus regions. Much of the measured far-infrared flux (69% at 60 micrometers and 47% at 100 micrometers) originates from regions associated with star formation rather than the extended, infrared cirrus component.

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.

Aromatic interactions impact ligand binding and function at serotonin 5-HT2C G protein-coupled receptors: receptor homology modelling, ligand docking, and molecular dynamics results validated by experimental studies

NASA Astrophysics Data System (ADS)

Córdova-Sintjago, Tania; Villa, Nancy; Fang, Lijuan; Booth, Raymond G.

2014-02-01

The serotonin (5-hydroxytryptamine, 5-HT) 5-HT2 G protein-coupled receptor (GPCR) family consists of types 2A, 2B, and 2C that share ∼75% transmembrane (TM) sequence identity. Agonists for 5-HT2C receptors are under development for psychoses; whereas, at 5-HT2A receptors, antipsychotic effects are associated with antagonists - in fact, 5-HT2A agonists can cause hallucinations and 5-HT2B agonists cause cardiotoxicity. It is known that 5-HT2A TM6 residues W6.48, F6.51, and F6.52 impact ligand binding and function; however, ligand interactions with these residues at the 5-HT2C receptor have not been reported. To predict and validate molecular determinants for 5-HT2C-specific activation, results from receptor homology modelling, ligand docking, and molecular dynamics simulation studies were compared with experimental results for ligand binding and function at wild type and W6.48A, F6.51A, and F6.52A point-mutated 5-HT2C receptors.

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 0.18w>=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).

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.

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.

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.

Innate predator recognition in giant pandas.

PubMed

Du, Yiping; Huang, Yan; Zhang, Hemin; Li, Desheng; Yang, Bo; Wei, Ming; Zhou, Yingmin; Liu, Yang

2012-02-01

Innate predator recognition confers a survival advantage to prey animals. We investigate whether giant pandas exhibit innate predator recognition. We analyzed behavioral responses of 56 naive adult captive giant pandas (Ailuropoda melanoleuca), to urine from predators and non-predators and water control. Giant pandas performed more chemosensory investigation and displayed flehmen behaviors more frequently in response to predator urine compared to both non-predator urine and water control. Subjects also displayed certain defensive behaviors, as indicated by vigilance, and in certain cases, fleeing behaviors. Our results suggest that there is an innate component to predator recognition in captive giant pandas, although such recognition was only slight to moderate. These results have implications that may be applicable to the conservation and reintroduction of this endangered species.

Entropic Elasticity in the Giant Muscle Protein Titin

NASA Astrophysics Data System (ADS)

Morgan, Ian; Saleh, Omar

Intrinsically disordered proteins (IDPs) are a large and functionally important class of proteins that lack a fixed three-dimensional structure. Instead, they adopt a conformational ensemble of states which facilitates their biological function as molecular linkers, springs, and switches. Due to their conformational flexibility, it can be difficult to study IDPs using typical experimental methods. To overcome this challenge, we use a high-resolution single-molecule magnetic stretching technique to quantify IDP flexibility. We apply this technique to the giant muscle protein titin, measuring its elastic response at low forces. We present results demonstrating that titin's native elastic response derives from the combined entropic elasticity of its ordered and disordered domains.

The Anatomy of the Perseus Spiral ARM: (sup 12)CO and IRAS Imaging Observations of the W3-W4-W5 Cloud Complex

NASA Technical Reports Server (NTRS)

Heyer, Mark H.; Terebey, S.; Oliversen, R. (Technical Monitor)

1998-01-01

Panoramic images of (sup l2)CO J = 1-0 and thermal dust emissions from the W3-W4-W5 region of the outer Galaxy are presented. These data and recently published H (sub I) 21 cm line emission images provide an approx. 1 min resolution perspective to the dynamics and thermal energy content of the interstellar gas and dust components contained within a 9 deg arc of the Perseus spiral arm. We tabulate the molecular properties of 1560 clouds identified as closed surfaces within the l-b-v CO data cube at a threshold of 0.9 K T(sup *)(sub R). Relative surface densities of the molecular (28:1) and atomic (2.5: 1) gas components determined within the arm and interarm velocity intervals demonstrate that the gas component that enters the spiral arm is predominantly atomic. Molecular clouds must necessarily condense from the compressed atomic material that enters the spiral arm and are likely short lived within the interarm regions. From the distribution of centroid velocities of clouds, we determine a random cloud-to-cloud velocity dispersion of 4 km/s over the width of the spiral arm but find no clear evidence within the molecular gas for streaming motions induced by the spiral potential. The far-infrared images are analyzed with the CO J = 1-0 and H (sub I) 21 cm line emission. The enhanced UV radiation field from members of the Cas OB6 association and embedded newborn stars provide a significant source of heating to the extended dust component within the Perseus arm relative to the quiescent cirrus regions. Much of the measured far-infrared flux (69% at 60 microns and 47% at 100 microns) originates from regions associated with star formation rather than the extended, infrared cirrus component.

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

HP2 survey. III. The California Molecular Cloud: A sleeping giant revisited

NASA Astrophysics Data System (ADS)

Lada, Charles J.; Lewis, John A.; Lombardi, Marco; Alves, João

2017-10-01

We present new high resolution and dynamic range dust column density and temperature maps of the California Molecular Cloud derived from a combination of Planck and Herschel dust-emission maps, and 2MASS NIR dust-extinction maps. We used these data to determine the ratio of the 2.2 μm extinction coefficient to the 850 μm opacity and found the value to be close to that found in similar studies of the Orion B and Perseus clouds but higher than that characterizing the Orion A cloud, indicating that variations in the fundamental optical properties of dust may exist between local clouds. We show that over a wide range of extinction, the column density probability distribution function (pdf) of the cloud can be well described by a simple power law (I.e., PDFN ∝ AK -n) with an index (n = 4.0 ± 0.1) that represents a steeper decline with AK than found (n ≈ 3) in similar studies of the Orion and Perseus clouds. Using only the protostellar population of the cloud and our extinction maps we investigate the Schmidt relation, that is, the relation between the protostellar surface density, Σ∗, and extinction, AK, within the cloud. We show that Σ∗ is directly proportional to the ratio of the protostellar and cloud pdfs, I.e., PDF∗(AK)/PDFN(AK). We use the cumulative distribution of protostars to infer the functional forms for both Σ∗ and PDF∗. We find that Σ∗ is best described by two power-law functions. At extinctions AK ≲ 2.5 mag, Σ∗ ∝ AK β with β = 3.3 while at higher extinctions β = 2.5, both values steeper than those (≈2) found in other local giant molecular clouds (GMCs). We find that PDF∗ is a declining function of extinction also best described by two power-laws whose behavior mirrors that of Σ∗. Our observations suggest that variations both in the slope of the Schmidt relation and in the sizes of the protostellar populations between GMCs are largely driven by variations in the slope, n, of PDFN(AK). This confirms earlier studies

Masses, luminosities and dynamics of galactic molecular clouds

NASA Technical Reports Server (NTRS)

Solomon, P. M.; Rivolo, A. R.; Mooney, T. J.; Barrett, J. W.; Sage, L. J.

1987-01-01

Star formation in galaxies takes place in molecular clouds and the Milky Way is the only galaxy in which it is possible to resolve and study the physical properties and star formation activity of individual clouds. The masses, luminosities, dynamics, and distribution of molecular clouds, primarily giant molecular clouds in the Milky Way are described and analyzed. The observational data sets are the Massachusetts-Stony Brook CO Galactic Plane Survey and the IRAS far IR images. The molecular mass and infrared luminosities of glactic clouds are then compared with the molecular mass and infrared luminosities of external galaxies.

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

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.

[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).

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

42 CFR 51.11-51.20 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false [Reserved] 51.11-51.20 Section 51.11-51.20 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS REQUIREMENTS APPLICABLE TO THE PROTECTION AND ADVOCACY FOR INDIVIDUALS WITH MENTAL ILLNESS PROGRAM Basic Requirements §§ 51.11-51...

Chromospheric activity of cool giant stars

NASA Technical Reports Server (NTRS)

Steiman-Cameron, T. Y.

1986-01-01

During the seventh year of IUE twenty-six spectra of seventeen cool giant stars ranging in spectral type from K3 thru M6 were obtained. Together with spectra of fifteen stars observed during the sixth year of IUE, these low-resolution spectra have been used to: (1) examine chromospheric activity in the program stars and late type giants in general, and (2) evaluate the extent to which nonradiative heating affects the upper levels of cool giant photospheres. The stars observed in this study all have well determined TiO band strengths, angular diameters (determined from lunar occulations), bolometric fluxes, and effective temperatures. Chromospheric activity can therefore be related to effective temperatures providing a clearer picture of activity among cool giant stars than previously available. The stars observed are listed.

The "DREAM" IODP project to drill the Mediterranean Salt Giant on the Balearic Promontory

NASA Astrophysics Data System (ADS)

Lofi, Johanna; Camerlenghi, Angelo; Aloisi, Giovanni; Maillard, Agnès; Garcia-Castellanos, Daniel; Huebscher, Christian; Kuroda, Junichiro

2017-04-01

should allow testing 1) the contradictory emplacement models that explain its genesis and 2) the presence of halophilic micro-organisms it may host/feed. DREAM is a part of a bigger Multi-phase IODP Drilling Project entitled "Uncovering a Salt Giant" (857-MDP, coord. A. Camerlenghi) born out of a series of workshops and international initiatives carried out since 2014. The DREAM pre-proposal P857B has been accepted by the IODP Science Evaluation Panel in January 2016. The full-proposal will be submitted after the acquisition of complementary Site Survey Data in 2017. The DREAM project is performed in close link with various international initiatives including the COST Action CA15103 and ANR Project MEDSALT (Camerlenghi et al., this congress) and the IMMAGE ICDP-IODP amphibious proposal (Flecker et al., this congress). DREAM co-proponents: J. Anton, M.A. Bassetti, D. Birgel, R. Bourillot, A. Caruso, H. Daigle, G. DeLange, F. Dela Pierre, R. Flecker, V. Gaullier, D. Hodell, F. Jimenez-Espejo, W. Krijgsman, L. Lourens, S. Lugli, V. Manzi, T. McGenity, J. McKenzie, P. Meijer, H. Moreno, A. Moscariello, P. Munch, N. Ohkouchi, J. Peckmann, P. Pezard, J. Poort, M. Roveri, F. Sierro, K. Takai, T. Treude.

A Partial Late Veneer for the Source of 3.8 Ga Isua Rocks: Evidence from Highly Siderophile Elements and 182W

NASA Astrophysics Data System (ADS)

Dale, C.; Kruijer, T.; Burton, K. W.; Kleine, T.; Moorbath, S.

2015-12-01

Highly siderophile elements (HSE) were strongly sequestered into metallic planetary cores, leaving silicate mantles almost devoid of HSE. Late accretion partially replenished HSE in planetary mantles soon after core formation had ceased [1], which for Earth probably postdated the giant Moon-forming impact. Ancient isolated domains in Earth's mantle - such as the source of 3.8 Ga Isua basalts - might represent mantle isolated from late accreted material, as suggested based on their small 182W excesses compared to Earth's present-day mantle [2]. However, such 182W excesses may also represent signatures of early differentiation in Earth's mantle, which have been preserved through the giant impact [3]. To assess the origin of 182W anomalies and the 182W composition of the pre-late veneer mantle, we determined HSE abundances and 182W compositions of a suite of mafic to ultramafic rocks from Isua. Our data show that the Isua source mantle had HSE abundances at ~60% of the present-day mantle, inconsistent with isolation from the late veneer. For the same samples we obtained a 13±4 ppm 182W excess over the modern terrestrial mantle, in excellent agreement with previous data [2]. Using a range of possible late veneer compositions and taking into account the recently revised 182W value for the Moon [4], we calculate that the Isua mantle source, containing 60% late veneer, would have a 182W value of 9±4 ppm, in very good agreement with the measured value for Isua. The combined HSE-W data, therefore, are consistent with only partial addition of the late veneer to the Isua mantle source, and with the interpretation that the 27±4 ppm 182W excess of the Moon represents the 182W composition of the pre-late veneer Earth's mantle [4]. [1] Dale et al. (2012) Science 336, 72. [2] Willbold et al. (2011) Nature 477, 195. [3] Touboul et al. (2012) Science 335, 1065-1069. [4] Kruijer et al. (2015) Nature 7548, 534

Entry Probe Missions to the Giant Planets

NASA Astrophysics Data System (ADS)

Spilker, T. R.; Atkinson, D. H.; Atreya, S. K.; Colaprete, A.; Cuzzi, J. N.; Spilker, L. J.; Coustenis, A.; Venkatapathy, E.; Reh, K.; Frampton, R.

2009-12-01

The primary motivation for in situ probe missions to the outer planets derives from the need to constrain models of solar system formation and the origin and evolution of atmospheres, to provide a basis for comparative studies of the gas and ice giants, and to provide a valuable link to extrasolar planetary systems. As time capsules of the solar system, the gas and ice giants offer a laboratory to better understand the atmospheric chemistries, dynamics, and interiors of all the planets, including Earth; and it is within the atmospheres and interiors of the giant planets that material diagnostic of the epoch of formation can be found, providing clues to the local chemical and physical conditions existing at the time and location at which each planet formed. Measurements of current conditions and processes in those atmospheres inform us about their evolution since formation and into the future, providing information about our solar system’s evolution, and potentially establishing a framework for recognizing extrasolar giant planets in different stages of their evolution. Detailed explorations and comparative studies of the gas and ice giant planets will provide a foundation for understanding the integrated dynamic, physical, and chemical origins, formation, and evolution of the solar system. To allow reliable conclusions from comparative studies of gas giants Jupiter and Saturn, an entry probe mission to Saturn is needed to complement the Galileo Probe measurements at Jupiter. These measurements provide the basis for a significantly better understanding of gas giant formation in the context of solar system formation. A probe mission to either Uranus or Neptune will be needed for comparative studies of the gas giants and the ice giants, adding knowledge of ice giant origins and thus making further inroads in our understanding of solar system formation. Recognizing Jupiter’s spatial variability and the need to understand its implications for global composition

New spectroscopic binary companions of giant stars and updated metallicity distribution for binary systems

NASA Astrophysics Data System (ADS)

Bluhm, P.; Jones, M. I.; Vanzi, L.; Soto, M. G.; Vos, J.; Wittenmyer, R. A.; Drass, H.; Jenkins, J. S.; Olivares, F.; Mennickent, R. E.; Vučković, M.; Rojo, P.; Melo, C. H. F.

2016-10-01

We report the discovery of 24 spectroscopic binary companions to giant stars. We fully constrain the orbital solution for 6 of these systems. We cannot unambiguously derive the orbital elements for the remaining stars because the phase coverage is incomplete. Of these stars, 6 present radial velocity trends that are compatible with long-period brown dwarf companions. The orbital solutions of the 24 binary systems indicate that these giant binary systems have a wide range in orbital periods, eccentricities, and companion masses. For the binaries with restricted orbital solutions, we find a range of orbital periods of between ~97-1600 days and eccentricities of between ~0.1-0.4. In addition, we studied the metallicity distribution of single and binary giant stars. We computed the metallicity of a total of 395 evolved stars, 59 of wich are in binary systems. We find a flat distribution for these binary stars and therefore conclude that stellar binary systems, and potentially brown dwarfs, have a different formation mechanism than planets. This result is confirmed by recent works showing that extrasolar planets orbiting giants are more frequent around metal-rich stars. Finally, we investigate the eccentricity as a function of the orbital period. We analyzed a total of 130 spectroscopic binaries, including those presented here and systems from the literature. We find that most of the binary stars with periods ≲30 days have circular orbits, while at longer orbital periods we observe a wide spread in their eccentricities. Based on observations collected at La Silla - Paranal Observatory under programs IDs IDs 085.C-0557, 087.C.0476, 089.C-0524, 090.C-0345, 096.A-9020 and through the Chilean Telescope Time under programs IDs CN2012A-73, CN2012B-47, CN2013A-111, CN2013B-51, CN2014A-52 and CN2015A-48.

The interstellar medium and star formation of galactic disks. I. Interstellar medium and giant molecular cloud properties with diffuse far-ultraviolet and cosmic-ray backgrounds

NASA Astrophysics Data System (ADS)

Li, Qi; Tan, Jonathan C.; Christie, Duncan; Bisbas, Thomas G.; Wu, Benjamin

2018-05-01

We present a series of adaptive mesh refinement hydrodynamic simulations of flat rotation curve galactic gas disks, with a detailed treatment of the interstellar medium (ISM) physics of the atomic to molecular phase transition under the influence of diffuse far-ultraviolet (FUV) radiation fields and cosmic-ray backgrounds. We explore the effects of different FUV intensities, including a model with a radial gradient designed to mimic the Milky Way. The effects of cosmic rays, including radial gradients in their heating and ionization rates, are also explored. The final simulations in this series achieve 4 pc resolution across the ˜20 kpc global disk diameter, with heating and cooling followed down to temperatures of ˜10 K. The disks are evolved for 300 Myr, which is enough time for the ISM to achieve a quasi-statistical equilibrium. In particular, the mass fraction of molecular gas is stabilized by ˜200 Myr. Additional global ISM properties are analyzed. Giant molecular clouds (GMCs) are also identified and the statistical properties of their populations are examined. GMCs are tracked as the disks evolve. GMC collisions, which may be a means of triggering star cluster formation, are counted and their rates are compared with analytic models. Relatively frequent GMC collision rates are seen in these simulations, and their implications for understanding GMC properties, including the driving of internal turbulence, are discussed.

Statistical study of defects caused by primary knock-on atoms in fcc Cu and bcc W using molecular dynamics

NASA Astrophysics Data System (ADS)

Warrier, M.; Bhardwaj, U.; Hemani, H.; Schneider, R.; Mutzke, A.; Valsakumar, M. C.

2015-12-01

We report on molecular Dynamics (MD) simulations carried out in fcc Cu and bcc W using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) code to study (i) the statistical variations in the number of interstitials and vacancies produced by energetic primary knock-on atoms (PKA) (0.1-5 keV) directed in random directions and (ii) the in-cascade cluster size distributions. It is seen that around 60-80 random directions have to be explored for the average number of displaced atoms to become steady in the case of fcc Cu, whereas for bcc W around 50-60 random directions need to be explored. The number of Frenkel pairs produced in the MD simulations are compared with that from the Binary Collision Approximation Monte Carlo (BCA-MC) code SDTRIM-SP and the results from the NRT model. It is seen that a proper choice of the damage energy, i.e. the energy required to create a stable interstitial, is essential for the BCA-MC results to match the MD results. On the computational front it is seen that in-situ processing saves the need to input/output (I/O) atomic position data of several tera-bytes when exploring a large number of random directions and there is no difference in run-time because the extra run-time in processing data is offset by the time saved in I/O.

Identification of canine parvovirus with the Q370R point mutation in the VP2 gene from a giant panda (Ailuropoda melanoleuca).

PubMed

Guo, Ling; Yang, Shao-lin; Chen, Shi-jie; Zhang, Zhihe; Wang, Chengdong; Hou, Rong; Ren, Yupeng; Wen, Xintian; Cao, Sanjie; Guo, Wanzhu; Hao, Zhongxiang; Quan, Zifang; Zhang, Manli; Yan, Qi-gui

2013-05-26

In this study, we sequenced and phylogenetic analyses of the VP2 genes from twelve canine parvovirus (CPV) strains obtained from eleven domestic dogs and a giant panda (Ailuropoda melanoleuca) in China. A novel canine parvovirus (CPV) was detected from the giant panda in China. Nucleotide and phylogenetic analysis of the capsid protein VP2 gene classified the CPV as a new CPV-2a type. Substitution of Gln for Arg at the conserved 370 residue in CPV presents an unusual variation in the new CPV-2a amino acid sequence of the giant panda and is further evidence for the continuing evolution of the virus. These findings extend the knowledge on CPV molecular epidemiology of particular relevance to wild carnivores.

Identification of canine parvovirus with the Q370R point mutation in the VP2 gene from a giant panda (Ailuropoda melanoleuca)

PubMed Central

2013-01-01

Background In this study, we sequenced and phylogenetic analyses of the VP2 genes from twelve canine parvovirus (CPV) strains obtained from eleven domestic dogs and a giant panda (Ailuropoda melanoleuca) in China. A novel canine parvovirus (CPV) was detected from the giant panda in China. Results Nucleotide and phylogenetic analysis of the capsid protein VP2 gene classified the CPV as a new CPV-2a type. Substitution of Gln for Arg at the conserved 370 residue in CPV presents an unusual variation in the new CPV-2a amino acid sequence of the giant panda and is further evidence for the continuing evolution of the virus. Conclusions These findings extend the knowledge on CPV molecular epidemiology of particular relevance to wild carnivores. PMID:23706032

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...

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.

An exploration hydrogeochemical study at the giant Pebble porphyry Cu-Au-Mo deposit, Alaska, USA, using high-resolution ICP-MS

USGS Publications Warehouse

Eppinger, Robert G.; Fey, David L.; Giles, Stuart A.; Kelley, Karen D.; Smith, Steven M.

2012-01-01

A hydrogeochemical study using high resolution ICP-MS was undertaken at the giant Pebble porphyry Cu-Au-Mo deposit and surrounding mineral occurrences. Surface water and groundwater samples from regional background and the deposit area were collected at 168 sites. Rigorous quality control reveals impressive results at low nanogram per litre (ng/l) levels. Sites with pH values below 5.1 are from ponds in the Pebble West area, where sulphide-bearing rubble crop is thinly covered. Relative to other study area waters, anomalous concentrations of Cu, Cd, K, Ni, Re, the REE, Tl, SO42− and F− are present in water samples from Pebble West. Samples from circum-neutral waters at Pebble East and parts of Pebble West, where cover is much thicker, have anomalous concentrations of Ag, As, In, Mn, Mo, Sb, Th, U, V, and W. Low-level anomalous concentrations for most of these elements were also found in waters surrounding nearby porphyry and skarn mineral occurrences. Many of these elements are present in low ng/l concentration ranges and would not have been detected using traditional quadrupole ICP-MS. Hydrogeochemical exploration paired with high resolution ICP-MS is a powerful new tool in the search for concealed deposits.

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.

Library of Giant Planet Reflection Spectra for WFirst and Future Space Telescopes

NASA Astrophysics Data System (ADS)

Smith, Adam J. R. W.; Fortney, Jonathan; Morley, Caroline; Batalha, Natasha E.; Lewis, Nikole K.

2018-01-01

Future large space space telescopes will be able to directly image exoplanets in optical light. The optical light of a resolved planet is due to stellar flux reflected by Rayleigh scattering or cloud scattering, with absorption features imprinted due to molecular bands in the planetary atmosphere. To aid in the design of such missions, and to better understand a wide range of giant planet atmospheres, we have built a library of model giant planet reflection spectra, for the purpose of determining effective methods of spectral analysis as well as for comparison with actual imaged objects. This library covers a wide range of parameters: objects are modeled at ten orbital distances between 0.5 AU and 5.0 AU, which ranges from planets too warm for water clouds, out to those that are true Jupiter analogs. These calculations include six metalicities between solar and 100x solar, with a variety of different cloud thickness parameters, and across all possible phase angles.

Light-induced propulsion of a giant liposome driven by peptide nanofibre growth.

PubMed

Inaba, Hiroshi; Uemura, Akihito; Morishita, Kazushi; Kohiki, Taiki; Shigenaga, Akira; Otaka, Akira; Matsuura, Kazunori

2018-04-19

Light-driven nano/micromotors are attracting much attention, not only as molecular devices but also as components of bioinspired robots. In nature, several pathogens such as Listeria use actin polymerisation machinery for their propulsion. Despite the development of various motors, it remains challenging to mimic natural systems to create artificial motors propelled by fibre formation. Herein, we report the propulsion of giant liposomes driven by light-induced peptide nanofibre growth on their surface. Peptide-DNA conjugates connected by a photocleavage unit were asymmetrically introduced onto phase-separated giant liposomes. Ultraviolet (UV) light irradiation cleaved the conjugates and released peptide units, which self-assembled into nanofibres, driving the translational movement of the liposomes. The velocity of the liposomes reflected the rates of the photocleavage reaction and subsequent fibre formation of the peptide-DNA conjugates. These results showed that chemical design of the light-induced peptide nanofibre formation is a useful approach to fabricating bioinspired motors with controllable motility.

Ice Giant Exploration

NASA Astrophysics Data System (ADS)

Rymer, A. M.; Arridge, C. S.; Masters, A.; Turtle, E. P.; Simon, A. A.; Hofstadter, M. D.; Turrini, D.; Politi, R.

2015-12-01

The Ice Giants in our solar system, Uranus and Neptune, are fundamentally different from their Gas Giant siblings Jupiter and Saturn, from the different proportions of rock and ice to the configuration of their planetary magnetic fields. Kepler space telescope discoveries of exo-planets indicate that planets of this type are among the most ubiquitous universally and therefore a future mission to explore the nature of the Ice Giants in our own solar system will provide insights into the nature of extra-solar system objects in general. Uranus has the smallest self- luminosity of all the planets, potentially related to catastrophic events early in the planet's history, which also may explain Uranus' large obliquity. Uranus' atmosphere is subject to extreme seasonal forcing making it unique in the Solar System. Neptune is also unique in a number of ways, notably its large moon Triton which is likely a captured Kuiper Belt Object and one of only two moons in the solar system with a robustly collisional atmosphere. Similar to Uranus, the angle between the solar wind and the magnetic dipole axis is subject to large-amplitude variations on both diurnal and seasonal timescales, but peculiarly it has one of the quietest magnetospheres of the solar system, at least according to Voyager 2, the only spacecraft to encounter Neptune to date. A comprehensive mission, as advocated in the Decadal Survey, would provide enormous science return but is also challenging and expensive. In this presentation we will discuss mission scenarios and suggest how collaboration between disciplines and internationally can help us to pursue a mission that includes Ice Giant exploration.

The complete mitochondrial genome and phylogenetic analysis of the giant panda (Ailuropoda melanoleuca).

PubMed

Peng, Rui; Zeng, Bo; Meng, Xiuxiang; Yue, Bisong; Zhang, Zhihe; Zou, Fangdong

2007-08-01

The complete mitochondrial genome sequence of the giant panda, Ailuropoda melanoleuca, was determined by the long and accurate polymerase chain reaction (LA-PCR) with conserved primers and primer walking sequence methods. The complete mitochondrial DNA is 16,805 nucleotides in length and contains two ribosomal RNA genes, 13 protein-coding genes, 22 transfer RNA genes and one control region. The total length of the 13 protein-coding genes is longer than the American black bear, brown bear and polar bear by 3 amino acids at the end of ND5 gene. The codon usage also followed the typical vertebrate pattern except for an unusual ATT start codon, which initiates the NADH dehydrogenase subunit 5 (ND5) gene. The molecular phylogenetic analysis was performed on the sequences of 12 concatenated heavy-strand encoded protein-coding genes, and suggested that the giant panda is most closely related to bears.

RESOLVING GIANT MOLECULAR CLOUDS IN NGC 300: A FIRST LOOK WITH THE SUBMILLIMETER ARRAY

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

Faesi, Christopher M.; Lada, Charles J.; Forbrich, Jan

2016-04-20

We present the first high angular resolution study of giant molecular clouds (GMCs) in the nearby spiral galaxy NGC 300, based on observations from the Submillimeter Array (SMA). We target eleven 500 pc sized regions of active star formation within the galaxy in the {sup 12}CO( J = 2-1) line at 40 pc spatial and 1 km s{sup −1} spectral resolution and identify 45 individual GMCs. We characterize the physical properties of these GMCs, and find that they are similar to GMCs in the disks of the Milky Way and other nearby spiral galaxies. For example, the GMC mass spectrummore » in our sample has a slope of 1.80 ± 0.07. Twelve clouds are spatially resolved by our observations, of which ten have virial mass estimates that agree to within a factor of two with mass estimates derived directly from {sup 12}CO integrated intensity, suggesting that the majority of these GMCs are bound. The resolved clouds show consistency with Larson’s fundamental relations between size, linewidth, and mass observed in the Milky Way. We find that the linewidth scales with the size as Δ V ∝ R {sup 0.52±0.20}, and the median surface density in the subsample is 54 M {sub ⊙} pc{sup −2}. We detect {sup 13}CO in four GMCs and find a mean {sup 12}CO/{sup 13}CO flux ratio of 6.2. Our interferometric observations recover between 30% and 100% of the integrated intensity from the APEX single dish {sup 12}CO observations of Faesi et al., suggesting the presence of low-mass GMCs and/or diffuse gas below our sensitivity limit. The fraction of APEX emission recovered increases with the SMA total intensity, as well as with the star formation rate.« less

Molecular-cloud-scale Chemical Composition. II. Mapping Spectral Line Survey toward W3(OH) in the 3 mm Band

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

Nishimura, Yuri; Watanabe, Yoshimasa; Yamamoto, Satoshi

To study a molecular-cloud-scale chemical composition, we conducted a mapping spectral line survey toward the Galactic molecular cloud W3(OH), which is one of the most active star-forming regions in the Perseus arm. We conducted our survey through the use of the Nobeyama Radio Observatory 45 m telescope, and observed the area of 16′ × 16′, which corresponds to 9.0 pc × 9.0 pc. The observed frequency ranges are 87–91, 96–103, and 108–112 GHz. We prepared the spectrum averaged over the observed area, in which eight molecular species (CCH, HCN, HCO{sup +}, HNC, CS, SO, C{sup 18}O, and {sup 13}CO) aremore » identified. On the other hand, the spectrum of the W3(OH) hot core observed at a 0.17 pc resolution shows the lines of various molecules such as OCS, H{sub 2}CS CH{sub 3}CCH, and CH{sub 3}CN in addition to the above species. In the spatially averaged spectrum, emission of the species concentrated just around the star-forming core, such as CH{sub 3}OH and HC{sub 3}N, is fainter than in the hot core spectrum, whereas emission of the species widely extended over the cloud such as CCH is relatively brighter. We classified the observed area into five subregions according to the integrated intensity of {sup 13}CO, and evaluated the contribution to the averaged spectrum from each subregion. The CCH, HCN, HCO{sup +}, and CS lines can be seen even in the spectrum of the subregion with the lowest {sup 13}CO integrated intensity range (<10 K km s{sup −1}). Thus, the contributions of the spatially extended emission is confirmed to be dominant in the spatially averaged spectrum.« less

Functional roles of H98 and W99 and β2α2 loop dynamics in the α-l-arabinofuranosidase from Thermobacillus xylanilyticus.

PubMed

Arab-Jaziri, Faten; Bissaro, Bastien; Barbe, Sophie; Saurel, Olivier; Débat, Hélène; Dumon, Claire; Gervais, Virginie; Milon, Alain; André, Isabelle; Fauré, Régis; O'Donohue, Michael J

2012-10-01

This study is focused on the elucidation of the functional role of the mobile β2α2 loop in the α-L-arabinofuranosidase from Thermobacillus xylanilyticus, and particularly on the roles of loop residues H98 and W99. Using site-directed mutagenesis, coupled to characterization methods including isothermal titration calorimetry (ITC) and saturation transfer difference nuclear magnetic resonance (STD-NMR) spectroscopy, and molecular dynamics simulations, it has been possible to provide a molecular level view of interactions and the consequences of mutations. Binding of para-nitrophenyl α-L-arabinofuranoside (pNP-α-l-Araf) to the wild-type arabinofuranosidase was characterized by K(d) values (0.32 and 0.16 mm, from ITC and STD-NMR respectively) that highly resembled that of the arabinoxylo-oligosaccharide XA(3)XX (0.21 mm), and determination of the thermodynamic parameters of enzyme : pNP-α-L-Araf binding revealed that this process is driven by favourable entropy, which is linked to the movement of the β2α2 loop. Loop closure relocates the solvent-exposed W99 into a buried location, allowing its involvement in substrate binding and in the formation of a functional active site. Similarly, the data underline the role of H98 in the ‘dynamic’ formation and definition of a catalytically operational active site, which may be a specific feature of a subset of GH51 arabinofuranosidases. Substitution of H98 and W99 by alanine or phenylalanine revealed that mutations affected K(M) and/or k(cat). Molecular dynamics performed on W99A implied that this mutation causes the loss of a hydrogen bond and leads to an alternative binding mode that is detrimental for catalysis. STD-NMR experiments revealed altered binding of the aglycon motif in the active site, combined with reduced STD intensities of the α-L-arabinofuranosyl moiety for W99 substitutions. © 2012 The Authors Journal compilation © 2012 FEBS.

Imaging phospholipid conformational disorder and packing in giant multilamellar liposome by confocal Raman microspectroscopy

NASA Astrophysics Data System (ADS)

Noothalapati, Hemanth; Iwasaki, Keita; Yoshimoto, Chikako; Yoshikiyo, Keisuke; Nishikawa, Tomoe; Ando, Masahiro; Hamaguchi, Hiro-o.; Yamamoto, Tatsuyuki

2017-12-01

Liposomes are closed phospholipid bilayer systems that have profound applications in fundamental cell biology, pharmaceutics and medicine. Depending on the composition (pure or mixture of phospholipids, presence of cholesterol) and preparation protocol, intra- and inter-chain molecular interactions vary leading to changes in the quality (order and packing) of liposomes. So far it is not possible to image conformational disorders and packing densities within a liposome in a straightforward manner. In this study, we utilized confocal Raman microspectroscopy to visualize structural disorders and packing efficiency within a giant multilamellar liposome model by focusing mainly on three regions in the vibrational spectrum (Csbnd C stretching, Csbnd H deformation and Csbnd H stretching). We estimated properties such as trans/gauche isomers and lateral packing probability. Interestingly, our Raman imaging studies revealed gel phase rich domains and heterogeneous lateral packing within the giant multilamellar liposome.

Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud. I. N159W

NASA Astrophysics Data System (ADS)

Lee, M.-Y.; Madden, S. C.; Lebouteiller, V.; Gusdorf, A.; Godard, B.; Wu, R.; Galametz, M.; Cormier, D.; Le Petit, F.; Roueff, E.; Bron, E.; Carlson, L.; Chevance, M.; Fukui, Y.; Galliano, F.; Hony, S.; Hughes, A.; Indebetouw, R.; Israel, F. P.; Kawamura, A.; Le Bourlot, J.; Lesaffre, P.; Meixner, M.; Muller, E.; Nayak, O.; Onishi, T.; Roman-Duval, J.; Sewiło, M.

2016-12-01

We present Herschel SPIRE Fourier Transform Spectrometer (FTS) observations of N159W, an active star-forming region in the Large Magellanic Cloud (LMC). In our observations, a number of far-infrared cooling lines, including carbon monoxide (CO) J = 4 → 3 to J = 12 → 11, [CI] 609 μm and 370 μm, and [NII] 205 μm, are clearly detected. With an aim of investigating the physical conditions and excitation processes of molecular gas, we first construct CO spectral line energy distributions (SLEDs) on 10 pc scales by combining the FTS CO transitions with ground-based low-J CO data and analyze the observed CO SLEDs using non-LTE (local thermodynamic equilibrium) radiative transfer models. We find that the CO-traced molecular gas in N159W is warm (kinetic temperature of 153-754 K) and moderately dense (H2 number density of (1.1-4.5) × 103 cm-3). To assess the impact of the energetic processes in the interstellar medium on the physical conditions of the CO-emitting gas, we then compare the observed CO line intensities with the models of photodissociation regions (PDRs) and shocks. We first constrain the properties of PDRs by modeling Herschel observations of [OI] 145 μm, [CII] 158 μm, and [CI] 370 μm fine-structure lines and find that the constrained PDR components emit very weak CO emission. X-rays and cosmic-rays are also found to provide a negligible contribution to theCO emission, essentially ruling out ionizing sources (ultraviolet photons, X-rays, and cosmic-rays) as the dominant heating source for CO in N159W. On the other hand, mechanical heating by low-velocity C-type shocks with 10 km s-1 appears sufficient enough to reproduce the observed warm CO. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.The final reduced Herschel data (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or

Generation of Late Mesozoic Qianlishan A2-type granite in Nanling Range, South China: Implications for Shizhuyuan W-Sn mineralization and tectonic evolution

NASA Astrophysics Data System (ADS)

Chen, Yuxiao; Li, He; Sun, Weidong; Ireland, Trevor; Tian, Xufeng; Hu, Yongbin; Yang, Wubin; Chen, Chen; Xu, Deru

2016-12-01

The Late Mesozoic Qianlishan granitic complex in the western Nanling Range, South China is associated with the Shizhuyuan giant W-Sn-Mo-Bi polymetallic deposit. It mainly consists of three phases of intrusions, P-1 porphyritic biotite granite, P-2 equigranular biotite granite and P-3 granite porphyry. All three phases of granite contain quartz, plagioclase, K-feldspar and Fe-rich biotite. They have geochemical affinities of A-type granites, e.g., high FeOT/(FeOT + MgO) ratios (0.84-0.99), total alkali (Na2O + K2O, 7.50-9.04 wt.%), high Ga/Al ratios (10,000*Ga/Al > 2.6) and high Zr + Nb + Y + Ce concentrations (> 350 ppm). High Y/Nb ratios (> 1.2) suggest that the Qianlishan complex belongs to A2-type granite. Zircon U-Pb ages indicate a short age interval decreasing from 158-157 Ma, to 158-155 Ma and to 154 Ma for the P-1, P-2 and P-3 granites, respectively. These ages are similar to the mineralization age of the Shizhuyuan tungsten polymetallic deposit, within error. The Qianlishan granites were generated at low oxygen fugacity conditions based on the low values of zircon Ce4 +/Ce3 + ratios (1.53-198) and significantly negative Eu anomalies (EuN/EuN*, 0.03-0.13) in apatite. New zircon εHf(t) values for the P-3 granite range from - 13.0 to - 4.4, similar to those previously obtained for the P-1 and P-2 granites. Both the granite and apatite grains therein are characterized by high F but low Cl concentrations, suggesting the influx of a high F/Cl component. The P-2 granites especially contain higher F contents (1840-8690 ppm) and W (7-158 ppm) and Sn (6-51 ppm) concentrations and with stronger evolution features. Positive trends between F and W and Sn of Qianlishan complex indicate that high F source is crucial for mineralization of W and Sn. We consider that the lithospheric mantle source may have been metasomatized by subduction fluids in the far end of subduction zones to produce the A2 feature of the Qianlishan granite and the fluorine was introduced through

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.

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

Merging W W and W W + jet with Minlo

DOE PAGES

Hamilton, Keith; Melia, Tom; Monni, Pier Francesco; ...

2016-09-12

We present a simulation program for the production of a pair of W bosons in association with a jet, that can be used in conjunction with general-purpose shower Monte Carlo generators, according to the Powheg method. We have further adapted and implemented the Minlo ' method on top of the NLO calculation underlying our W + W - + jet generator. Thus, the resulting simulation achieves NLO accuracy not only for inclusive distributions in W + W - + jet production but also W + W - production, i.e. when the associated jet is not resolved, without the introduction ofmore » any unphysical merging scale. This work represents the first extension of the Minlo ' method, in its original form, to the case of a genuine underlying 2 → 2 process, with non-trivial virtual corrections.« less

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.

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.

Star formation in the Auriga-California Giant Molecular Cloud and its circumstellar disk population

NASA Astrophysics Data System (ADS)

Broekhoven-Fiene, Hannah

2016-05-01

This thesis presents a multiwavelength analysis, from the infrared to the microwave, of the young, forming stars in the Auriga-California Molecular Cloud and a first look at the disks they host and their potential for forming planetary systems. At the beginning of this thesis, Auriga-Cal had only recently been identified as one contiguous cloud with its distance placing it within the Gould Belt of nearby star-forming regions (Lada et al. 2009). This thesis presents the largest body of work to date on Auriga-Cal's star formation and disk population. Auriga-Cal is one of two nearby giant molecular clouds (GMCs) in the Gould Belt, the other being the Orion A molecular cloud. These two GMCs have similar mass ( 10^5 Msolar), spatial scale ( 80 pc), distance ( 450 pc), and filamentary morphology, yet the two clouds present very different star formation qualities and quantities. Namely, Auriga-Cal is forming far fewer stars and does not exhibit the high-mass star formation seen in Orion A. In this thesis, I present a census of the star forming objects in the infrared with the Spitzer Space Telescope showing that Auriga-Cal contains at least 166 young stellar objects (YSOs), 15-20x fewer stars than Orion A, the majority of which are located in the cluster around LkHalpha 101, NGC 1529, and the filament extending from it. I find the submillimetre census with the James Clerk Maxwell Telescope, sensitive to the youngest objects, arrives at a similar result showing the disparity between the two clouds observed in the infrared continues to the submillimetre. Therefore the relative star formation rate between the two clouds has remained constant in recent times. The final chapter introduces the first study targeted at the disk population to measure the formation potential of planetary systems around the young stars in Auriga-Cal. The dust thermal emission at cm wavelengths is observed to measure the relative amounts of cm-sized grains, indicative of the grain growth processes

Preparation of giant myelin vesicles and proteoliposomes to register ionic channels.

PubMed

Regueiro, P; Monreal, J; Díaz, R S; Sierra, F

1996-11-01

Myelin vesicles, reconstituted liposomes with proteolipid protein (PLP), the main protein component of myelin, and electrophysiological patch-clamp are potentially powerful tools to study the role of myelin in functional ionic channels. However, technical difficulties in the vesiculation of myelin and the small size of the vesicles obtained do not permit the application of micropipettes for current recordings. From a suspension of purified myelin we have prepared oligolamellar vesicles (mean diameter of 144 nm) using the so-called French pressure system. From this preparation we obtained giant myelin vesicles approximately 10 microns in mean diameter, using a dehydration-rehydration procedure. Qualitative analysis of proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed no significant loss of any component in these vesicles due to pressure, in comparison with non-vesiculated myelin. A way of preparing giant liposomes of approximately 80-100 microns and proteoliposomes of approximately 30 microns in mean diameter, using the same dehydration-rehydration procedure, is also reported. Reconstitution of purified PLP in giant liposomes was confirmed by fluorescent labeling of PLP and by fluorescence microscopy. The current recordings from these vesicles prove the validity of these methods and provide significant evidence of the existence of ionic channels in myelin membranes and the possibility that PLP functions as a channel. The physiological significance and characterization of these channels remain yet unresolved. These results have a special significance for elucidating the molecular role of myelin in the regulation of neural activity and in the brain ion microenvironment.

Molecular cloning, characterization, and bioactivity analysis of interleukin 18 in giant panda (Ailuropoda melanoleuca).

PubMed

Yan, Y; Wang, Q; Niu, L L; Deng, J B; Yu, J Q; Zhang J X Wang, Y Z; Yin, M M; Tan, X M

2014-11-19

Interleukin 18 (IL-18), as a member of IL-1 superfamily, is an important pleiotropic cytokine that modulates Th1 immune responses. In this report, we cloned and identified a homolog of IL-18 in giant panda (Ailuropoda melanoleuca) (designated as AmIL-18) from peripheral blood mononuclear cells stimulated with lipopolysaccharide. The open readin g frame of AmIL-18 cDNA is 579 bp encoding a deduced protein of 192 amino acids. AmIL-18 gDNA fragments contained 5 exons and 4 introns. The amino acid sequence of AmIL-18 shared 23.9 to 87.0% identity with other species. To evaluate the effects of AmIL-18 on the immune response, we expressed the recombinant AmIL-18 in Escherichia coli BL21 (DE3). The fusion protein PET-AmIL-18 was purified by nickel affinity column chromatography and verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis. The biological function of purified PET-AmIL-18 was determined on mouse splenocytes by quantitative real-time polymerase chain reaction. INF-γ and other cytokines were increased when stimulated by PET-AmIL-18, particularly when combined with recombinant human interleukin 12, while a Th2-type cytokine, interleukin-4, was strikingly suppressed. These results will provide information for the potential use of recombinant proteins to manipulate the immune response in giant pandas and facilitate the study to protect this treasured species.

Giant MACPF/CDC pore forming toxins: A class of their own.

PubMed

Reboul, Cyril F; Whisstock, James C; Dunstone, Michelle A

2016-03-01

Pore Forming Toxins (PFTs) represent a key mechanism for permitting the passage of proteins and small molecules across the lipid membrane. These proteins are typically produced as soluble monomers that self-assemble into ring-like oligomeric structures on the membrane surface. Following such assembly PFTs undergo a remarkable conformational change to insert into the lipid membrane. While many different protein families have independently evolved such ability, members of the Membrane Attack Complex PerForin/Cholesterol Dependent Cytolysin (MACPF/CDC) superfamily form distinctive giant β-barrel pores comprised of up to 50 monomers and up to 300Å in diameter. In this review we focus on recent advances in understanding the structure of these giant MACPF/CDC pores as well as the underlying molecular mechanisms leading to their formation. Commonalities and evolved variations of the pore forming mechanism across the superfamily are discussed. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

28 CFR 51.51 - Purpose of the subpart.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Purpose of the subpart. 51.51 Section 51.51 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PROCEDURES FOR THE ADMINISTRATION OF SECTION 5 OF THE VOTING RIGHTS ACT OF 1965, AS AMENDED Determinations by the Attorney General § 51.51...

28 CFR 51.51 - Purpose of the subpart.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Purpose of the subpart. 51.51 Section 51.51 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PROCEDURES FOR THE ADMINISTRATION OF SECTION 5 OF THE VOTING RIGHTS ACT OF 1965, AS AMENDED Determinations by the Attorney General § 51.51...

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

MD simulations of low energy deuterium irradiation on W, WC and W2C surfaces

NASA Astrophysics Data System (ADS)

Lasa, A.; Björkas, C.; Vörtler, K.; Nordlund, K.

2012-10-01

According to the present design beryllium (Be), tungsten (W) and carbon (C) will be the plasma facing materials in the ITER fusion reactor. Due to sputtering and subsequent re-deposition, mixing of these materials will occur. In this context, molecular dynamics simulations of cumulative, low energy and high flux D bombardment of pure W and tungsten carbides (WC, W2C) were carried out. The retention and sputtering properties as well as the structural deformation were analysed and comparisons to SDTrimSP simulations were made. Almost no tungsten is sputtered in the energy range considered and the D backscattering is lower in pure tungsten than in any of the tungsten carbides. In WC and W2C, the deuterium is mainly trapped forming small molecules, whereas mostly atomic D is present in pure W. The C sputtering increases with C content in the material, and shows a peak at the bombardment energy ˜50 eV, most likely due to the swift chemical sputtering mechanism. Pure W is seen to lose its crystallinity in the areas where D is present. After the D irradiation, the composition of both WC and W2C is mostly W in the topmost layers, due to preferential sputtering of C, an amorphous D-C mixture underneath and an undisturbed lattice in the rest of the cell.

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.

Giant liposarcoma of the esophagus: A case report

PubMed Central

Lin, Zhi-Chao; Chang, Xiang-Zhen; Huang, Xiu-Fang; Zhang, Chun-Lai; Yu, Geng-Sheng; Wu, Shuo-Yun; Ye, Min; He, Jian-Xing

2015-01-01

Liposarcomas rarely develop in the aerodigestive tract. Here, we present a primary esophageal liposarcoma that was discovered between the T3 and T7 levels of the esophagus during right pleural exploration of a 51-year-old male patient. The patient had presented with non-specific symptoms, including progressive dysphagia over the previous 6 mo, without complaints of chest or epigastric pain, regurgitation, or weight loss. A radical three-hole esophagectomy was performed. The tumor was extremely large (14 cm × 7.0 cm × 6.5 cm), but completely encapsulated. Upon histological examination, the tumor was diagnosed as a giant, well-differentiated esophageal liposarcoma with a dedifferentiated component. Non-specific radiological and endoscopic results during the clinical work-up delayed diagnosis until post-operative histology was performed. In this report, the clinical, radiological and endoscopic diagnostic challenges specific to the case are discussed, as well as the surgical and pathological findings. PMID:26361432

Kinematics of Ultra-high-velocity Gas in the Expanding Molecular Shell Adjacent to the W44 Supernova Remnant

NASA Astrophysics Data System (ADS)

Yamada, Masaya; Oka, Tomoharu; Takekawa, Shunya; Iwata, Yuhei; Tsujimoto, Shiho; Tokuyama, Sekito; Furusawa, Maiko; Tanabe, Keisuke; Nomura, Mariko

2017-01-01

We mapped the ultra-high-velocity feature (the “Bullet”) detected in the expanding molecular shell associated with the W44 supernova remnant using the Nobeyama Radio Observatory 45 m telescope and the Atacama Submillimeter Telescope Experiment 10 m telescope. The Bullet clearly appears in the CO J = 1-0, CO J = 3-2, CO J = 4-3, and HCO+ J = 1-0 maps with a compact appearance (0.5 × 0.8 pc2) and an extremely broad-velocity width (ΔV ≃ 100 km s-1). The line intensities indicate that the Bullet has a higher density and temperature than those in the expanding molecular shell. The kinetic energy of the Bullet amounts to 1048.0 erg, which is approximately 1.5 orders of magnitude greater than the kinetic energy shared to the small solid angle of it. Two possible formation scenarios with an inactive isolated black hole are presented.

KINEMATICS OF ULTRA-HIGH-VELOCITY GAS IN THE EXPANDING MOLECULAR SHELL ADJACENT TO THE W44 SUPERNOVA REMNANT

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

Yamada, Masaya; Oka, Tomoharu; Takekawa, Shunya

We mapped the ultra-high-velocity feature (the “Bullet”) detected in the expanding molecular shell associated with the W44 supernova remnant using the Nobeyama Radio Observatory 45 m telescope and the Atacama Submillimeter Telescope Experiment 10 m telescope. The Bullet clearly appears in the CO J = 1–0, CO J = 3–2, CO J = 4–3, and HCO{sup +} J = 1–0 maps with a compact appearance (0.5 × 0.8 pc{sup 2}) and an extremely broad-velocity width (Δ V ≃ 100 km s{sup −1}). The line intensities indicate that the Bullet has a higher density and temperature than those in the expandingmore » molecular shell. The kinetic energy of the Bullet amounts to 10{sup 48.0} erg, which is approximately 1.5 orders of magnitude greater than the kinetic energy shared to the small solid angle of it. Two possible formation scenarios with an inactive isolated black hole are presented.« less

51. VIEW OF LORAL ADS 100A COMPUTERS LOCATED CENTRALLY ON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

51. VIEW OF LORAL ADS 100A COMPUTERS LOCATED CENTRALLY ON NORTH WALL OF TELEMETRY ROOM (ROOM 106). SLC-3W CONTROL ROOM IS VISIBLE IN BACKGROUND THROUGH WINDOW IN NORTH WALL. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

LITHIUM-RICH GIANTS IN GLOBULAR CLUSTERS

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

Kirby, Evan N.; Cohen, Judith G.; Guhathakurta, Puragra

Although red giants deplete lithium on their surfaces, some giants are Li-rich. Intermediate-mass asymptotic giant branch (AGB) stars can generate Li through the Cameron–Fowler conveyor, but the existence of Li-rich, low-mass red giant branch (RGB) stars is puzzling. Globular clusters are the best sites to examine this phenomenon because it is straightforward to determine membership in the cluster and to identify the evolutionary state of each star. In 72 hours of Keck/DEIMOS exposures in 25 clusters, we found four Li-rich RGB and two Li-rich AGB stars. There were 1696 RGB and 125 AGB stars with measurements or upper limits consistentmore » with normal abundances of Li. Hence, the frequency of Li-richness in globular clusters is (0.2 ± 0.1)% for the RGB, (1.6 ± 1.1)% for the AGB, and (0.3 ± 0.1)% for all giants. Because the Li-rich RGB stars are on the lower RGB, Li self-generation mechanisms proposed to occur at the luminosity function bump or He core flash cannot explain these four lower RGB stars. We propose the following origin for Li enrichment: (1) All luminous giants experience a brief phase of Li enrichment at the He core flash. (2) All post-RGB stars with binary companions on the lower RGB will engage in mass transfer. This scenario predicts that 0.1% of lower RGB stars will appear Li-rich due to mass transfer from a recently Li-enhanced companion. This frequency is at the lower end of our confidence interval.« less

Giant cell arteritis of fallopian tube.

PubMed

Azzena, A; Altavilla, G; Salmaso, R; Vasoin, F; Pellizzari, P; Doria, A

1994-01-01

One case of giant cells arteritis involving tubaric arteries in a postmenopausal woman is described. The patient was 59 years old and presented with asthenia, anemia, fever, weight loss, an abdominal palpable mass and elevated erythrocyte sedimentation rate. Exploratory laparotomy revealed a large ovarian cyst of 14 cm in diameter. Extensive giant cell arteritis, Horton's type, of the small-sizes arteries was found unexpectedly in the fallopian tube of the patient who had had a prior ovariectomy. Giant cell arteritis of the female genital tract is a rare finding in elderly women and may occur as an isolated finding or as part of generalised arteritis.

42 CFR 51.33-51.40 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false [Reserved] 51.33-51.40 Section 51.33-51.40 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS REQUIREMENTS APPLICABLE TO THE PROTECTION AND ADVOCACY FOR INDIVIDUALS WITH MENTAL ILLNESS PROGRAM Protection and Advocacy...

42 CFR 51.28-51.30 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false [Reserved] 51.28-51.30 Section 51.28-51.30 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS REQUIREMENTS APPLICABLE TO THE PROTECTION AND ADVOCACY FOR INDIVIDUALS WITH MENTAL ILLNESS PROGRAM Program Administration and...

Supernova Remnant W49B and Its Environment

NASA Astrophysics Data System (ADS)

Zhu, H.; Tian, W. W.; Zuo, P.

2014-10-01

We study gamma-ray supernova remnant (SNR) W49B and its environment using recent radio and infrared data. Spitzer Infrared Spectrograph low resolution data of W49B shows shocked excitation lines of H2 (0,0) S(0)-S(7) from the SNR-molecular cloud interaction. The H2 gas is composed of two components with temperatures of ~260 K and ~1060 K, respectively. Various spectral lines from atomic and ionic particles are detected toward W49B. We suggest that the ionic phase has an electron density of ~500 cm-3 and a temperature of ~104 K by the spectral line diagnoses. The mid- and far-infrared data from MSX, Spitzer, and Herschel reveal a 151 ± 20 K hot dust component with a mass of 7.5 ± 6.6 × 10-4 M ⊙ and a 45 ± 4 K warm dust component with a mass of 6.4 ± 3.2 M ⊙. The hot dust is likely from materials swept up by the shock of W49B. The warm dust may possibly originate from the evaporation of clouds interacting with W49B. We build the H I absorption spectra of W49B and four nearby H II regions (W49A, G42.90+0.58, G42.43-0.26, and G43.19-0.53) and study the relation between W49B and the surrounding molecular clouds by employing the 2.12 μm infrared and CO data. We therefore obtain a kinematic distance of ~10 kpc for W49B and suggest that the remnant is likely associated with the CO cloud at about 40 km s-1.

Isolation and molecular identification of planctomycete bacteria from postlarvae of the giant tiger prawn, Penaeus monodon.

PubMed Central

Fuerst, J A; Gwilliam, H G; Lindsay, M; Lichanska, A; Belcher, C; Vickers, J E; Hugenholtz, P

1997-01-01

Bacteria phenotypically resembling members of the phylogenetically distinct planctomycete group of the domain Bacteria were isolated from postlarvae of the giant tiger prawn, Penaeus monodon. A selective medium designed in the light of planctomycete antibiotic resistance characteristics was used for this isolation. Planctomycetes were isolated from both healthy and monodon baculovirus-infected prawn postlarvae. The predominant colony type recovered from postlarvae regardless of viral infection status was nonpigmented. Other, less commonly observed types were pink or orange pigmented. A planctomycete-specific 16S rRNA-directed probe was designed and used to screen the isolates for their identity as planctomycetes prior to molecular phylogenetic characterization. 16S rRNA genes from nine prawn isolates together with two planctomycete reference strains (Planctomyces brasiliensis and Gemmata obscuriglobus) were sequenced and compared with reference sequences from the planctomycetes and other members of the domain Bacteria. Phylogenetic analyses and sequence signatures of the 16S rRNA genes demonstrated that the prawn isolates were members of the planctomycete group. Five representatives of the predominant nonpigmented colony type were members of the Pirellula group within the planctomycetes, as were three pink-pigmented colony type representatives. Homology values and tree topology indicated that representatives of the nonpigmented and pink-pigmented colony types formed two discrete clusters within the Pirellula group, not identical to any known Pirellula species. A sole representative of the orange colony type was a member of the Planctomyces group, virtually identical in 16S rDNA sequence to P. brasiliensis, and exhibited distinctive morphology. PMID:8979353

FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN): Molecular clouds toward W ; possible evidence for a cloud-cloud collision triggering O star formation

NASA Astrophysics Data System (ADS)

Kohno, Mikito; Torii, Kazufumi; Tachihara, Kengo; Umemoto, Tomofumi; Minamidani, Tetsuhiro; Nishimura, Atsushi; Fujita, Shinji; Matsuo, Mitsuhiro; Yamagishi, Mitsuyoshi; Tsuda, Yuya; Kuriki, Mika; Kuno, Nario; Ohama, Akio; Hattori, Yusuke; Sano, Hidetoshi; Yamamoto, Hiroaki; Fukui, Yasuo

2018-05-01

We observed molecular clouds in the W 33 high-mass star-forming region associated with compact and extended H II regions using the NANTEN2 telescope as well as the Nobeyama 45 m telescope in the J = 1-0 transitions of 12CO, 13CO, and C18O as part of the FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN) legacy survey. We detected three velocity components at 35 km s-1, 45 km s-1, and 58 km s-1. The 35 km s-1 and 58 km s-1 clouds are likely to be physically associated with W 33 because of the enhanced 12CO J = 3-2 to J = 1-0 intensity ratio as R_3-2/1-0 > 1.0 due to the ultraviolet irradiation by OB stars, and morphological correspondence between the distributions of molecular gas and the infrared and radio continuum emissions excited by high-mass stars. The two clouds show complementary distributions around W 33. The velocity separation is too large to be gravitationally bound, and yet not explained by expanding motion by stellar feedback. Therefore, we discuss whether a cloud-cloud collision scenario likely explains the high-mass star formation in W 33.

Lithium Abundance in M3 Red Giant

NASA Astrophysics Data System (ADS)

Givens, Rashad; Pilachowski, Catherine A.

2015-01-01

We present the abundance of lithium in the red giant star vZ 1050 (SK 291) in the globular cluster M3. A previous survey of giants in the cluster showed that like IV-101, vZ 1050 displays a prominent Li I 6707 Å feature. vZ 1050 lies on the blue side of the red giant branch about 1.3 magnitudes above the level of the horizontal branch, and may be an asymptotic giant branch star. A high resolution spectrum of M3 vZ1050 was obtained with the ARC 3.5m telescope and the ARC Echelle Spectrograph (ARCES). Atmospheric parameters were determined using Fe I and Fe II lines from the spectrum using the MOOG spectral analysis program, and the lithium abundance was determined using spectrum synthesis.

Giant Cell Arteritis Presenting as Scalp Necrosis

PubMed Central

Maidana, Daniel E.; Muñoz, Silvia; Acebes, Xènia; Llatjós, Roger; Jucglà, Anna; Álvarez, Alba

2011-01-01

The differential of scalp ulceration in older patients should include several causes, such as herpes zoster, irritant contact dermatitis, ulcerated skin tumors, postirradiation ulcers, microbial infections, pyoderma gangrenosum, and giant cell arteritis. Scalp necrosis associated with giant cell arteritis was first described in the 1940s. The presence of this dermatological sign within giant cell arteritis represents a severity marker of this disease, with a higher mean age at diagnosis, an elevated risk of vision loss and tongue gangrene, as well as overall higher mortality rates, in comparison to patients not presenting this manifestation. Even though scalp necrosis due to giant cell arteritis is exceptional, a high level of suspicion must be held for this clinical finding, in order to initiate prompt and proper treatment and avoid blindness. PMID:21789466

Discovery of a Molecular Collision Front in Interacting Galaxies NGC 4567/4568 with ALMA

NASA Astrophysics Data System (ADS)

Kaneko, Hiroyuki; Kuno, Nario; Saitoh, Takayuki R.

2018-06-01

We present results of 12CO(J = 1–0) imaging observations of NGC 4567/4568, a galaxy pair in a close encounter, with the Atacama Large Millimeter/Submillimeter Array (ALMA). For the first time, we find clear evidence of a molecular collision front with a velocity dispersion that is 16.8 ± 1.4 km s‑1 at the overlapping region, owing to high spatial and velocity resolution. By integrating over the velocity width that corresponds to the molecular collision front, we find a long filamentary structure with a size of 1800 pc × 350 pc at the collision front. This filamentary molecular structure spatially coincides with a dark lane seen in the R-band image. We find four molecular clouds in the filament, each with a radius of 30 pc and mass of 106 M ⊙ the radii matching a typical value for giant molecular clouds (GMCs) and the masses corresponding to those between GMCs and giant molecular associations (GMAs). All four clouds are gravitationally bound. The molecular filamentary structure and its physical conditions are similar to the structure expected via numerical simulation. The filament could be a progenitor of super star clusters.

The Giant Cell.

ERIC Educational Resources Information Center

Stockdale, Dennis

1998-01-01

Provides directions for the construction of giant plastic cells, including details for building and installing the organelles. Also contains instructions for preparing the ribosomes, nucleolus, nucleus, and mitochondria. (DDR)

Studies of the Long Secondary Periods in Pulsating Red Giants. II. Lower-Luminosity Stars

NASA Astrophysics Data System (ADS)

Percy, J. R.; Leung, H. W.

2017-06-01

We have used AAVSO visual and photoelectric V data, and the AAVSO time-series package VSTAR and the Lomb-Scargle time-series algorithm to determine improved pulsation periods, "long secondary periods" (LSPs), and their amplitudes in 51 shorter-period pulsating red giants in the AAVSO photoelectric photometry program, and in the AAVSO long-period variable (LPV) binocular program. As is well known, radial pulsation becomes detectable in red giants at about spectral type M0, with periods of about 20 days. We find that the LSP phenomenon is also first detectable at about M0. Pulsation and LSP amplitudes increase from near zero to about 0.1 at pulsation periods of 100 days. At longer periods, the pulsation amplitudes continue to increase, but the LSP amplitudes are generally between 0.1 and 0.2 on average. The ratios of LSP to pulsation period cluster around 5 and 10, presumably depending on whether the pulsation period is the fundamental or first overtone. The pulsation and LSP phase curves are generally close to sinusoidal, except when the amplitude is small, in which case they may be distorted by observational scatter or, in the case of the LSP amplitude, by the pulsational variability. As with longer-period stars, the LSP amplitude i ncreases and decreases by a factor of two or more, for unknown reasons, on a time scale of about 20 LSPs. The LSP phenomenon is thus present and similar in radially pulsating red giants of all periods. Its cause remains unknown.

40 CFR 51.1001 - Applicability of part 51.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Applicability of part 51. 51.1001 Section 51.1001 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... PM2.5 National Ambient Air Quality Standards § 51.1001 Applicability of part 51. The provisions in...

40 CFR 51.1001 - Applicability of part 51.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Applicability of part 51. 51.1001 Section 51.1001 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... PM2.5 National Ambient Air Quality Standards § 51.1001 Applicability of part 51. The provisions in...

40 CFR 51.1001 - Applicability of part 51.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Applicability of part 51. 51.1001 Section 51.1001 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... PM2.5 National Ambient Air Quality Standards § 51.1001 Applicability of part 51. The provisions in...

40 CFR 51.1001 - Applicability of part 51.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Applicability of part 51. 51.1001 Section 51.1001 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... PM2.5 National Ambient Air Quality Standards § 51.1001 Applicability of part 51. The provisions in...

40 CFR 51.1001 - Applicability of part 51.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Applicability of part 51. 51.1001 Section 51.1001 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... PM2.5 National Ambient Air Quality Standards § 51.1001 Applicability of part 51. The provisions in...

Evolution and history of Giant Sequoia

Treesearch

H. Thomas Harvey

1986-01-01

Ancient ancestors of the giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz) were widespread throughout much of the Northern Hemisphere during the late Mesozoic Period. Climatic conditions changed, forcing the more recent ancestors of present giant sequoia into the southwestern United States. The native range is now restricted to the west slope of the Sierra...

Metastatic giant basal cell carcinoma: a case report.

PubMed

Bellahammou, Khadija; Lakhdissi, Asmaa; Akkar, Othman; Rais, Fadoua; Naoual, Benhmidou; Elghissassi, Ibrahim; M'rabti, Hind; Errihani, Hassan

2016-01-01

Basal cell carcinoma is the most common skin cancer, characterised by a slow growing behavior, metastasis are extremely rare, and it occurs in less than 0, 1% of all cases. Giant basal cell carcinoma is a rare form of basal cell carcinoma, more aggressive and defined as a tumor measuring more than 5 cm at its largest diameter. Only 1% of all basal cell carcinoma develops to a giant basal cell carcinoma, resulting of patient's negligence. Giant basal cell carcinoma is associated with higher potential of metastasis and even death, compared to ordinary basal cell carcinoma. We report a case of giant basal cell carcinoma metastaticin lung occurring in a 79 years old male patient, with a fatal evolution after one course of systemic chemotherapy. Giant basal cell carcinoma is a very rare entity, early detection of these tumors could prevent metastasis occurrence and improve the prognosis of this malignancy.

Imaging Active Giants and Comparisons to Doppler Imaging

NASA Astrophysics Data System (ADS)

Roettenbacher, Rachael

2018-04-01

In the outer layers of cool, giant stars, stellar magnetism stifles convection creating localized starspots, analogous to sunspots. Because they frequently cover much larger regions of the stellar surface than sunspots, starspots of giant stars have been imaged using a variety of techniques to understand, for example, stellar magnetism, differential rotation, and spot evolution. Active giants have been imaged using photometric, spectroscopic, and, only recently, interferometric observations. Interferometry has provided a way to unambiguously see stellar surfaces without the degeneracies experienced by other methods. The only facility presently capable of obtaining the sub-milliarcsecond resolution necessary to not only resolve some giant stars, but also features on their surfaces is the Center for High-Angular Resolution Astronomy (CHARA) Array. Here, an overview will be given of the results of imaging active giants and details on the recent comparisons of simultaneous interferometric and Doppler images.

STS 51-D crew photograph in orbit

NASA Image and Video Library

1985-04-14

51D-09-034 (12-19 April 1985) --- The seven crew members of STS-51D take time, during a busy full week in space, to pose for a "star-burst" type in-space portrait. Hold picture with astronaut Rhea Seddon at bottom center. Counter-clockwise from the bottom left are Jeffrey A. Hoffman, mission specialist; Dr. Seddon, mission specialist; Charles D. Walker, payload specialist; U. S. Senator E. J. (Jake) Garn, payload specialist; S. David Griggs, mission specialist; Karol J. Bobko, mission commander; and Donald W. Williams, pilot. A pre-set 35mm camera exposed the frame in the mid-deck of the Earth-orbiting Space Shuttle Discovery. The crew launched at 8:59 a.m. (EST), April 12, 1985 and landed at 8:54 a.m. (EST), April 19, 1985 spending five minutes less than a full week on the busy mission.

Characterization of a new 1,3-1,4-β-glucanase gene from Bacillus tequilensis CGX5-1.

PubMed

Wang, Jinjing; Niu, Chengtuo; Liu, Xiaoling; Chen, Xi; Li, Qi

2014-06-01

1,3-1,4-β-Glucanase received great interest due to its application in brewing and feed industries. Application of 1,3-1,4-β-glucanase in brewing industry helps make up for the defect that plant-derived β-glucanases are heat-sensitive. A new strain, CGX5-1, exhibited remarkable 1,3-1,4-β-glucanase, was isolated from Asian giant hornet nest and identified Bacillus tequilensis. Moreover, a new 1,3-1,4-β-glucanase gene from B. tequilensis was cloned and measured to be 720 bp encoding 239 amino acids, with a predicted molecular weight of 26.9 kDa. After expressed in Escherichia coli BL21, active recombinant enzyme of 24 kDa was detected in the supernatant of cell culture, with the activity of 2,978.2 U/mL. The new enzyme was stable in the pH 5.0-7.5 with the highest activity measured at pH 6.0. Moreover, it is thermostable within 45 to 60 °C. The property of the new recombinant enzyme makes this enzyme a broad prospect in brewing industry. Moreover, this is the first report on 1,3-1,4-β-glucanase produced by B. tequilensis.

Giant cell arteritis: a review.

PubMed

Patil, Pravin; Karia, Niral; Jain, Shaifali; Dasgupta, Bhaskar

2013-01-01

Giant cell arteritis is the most common vasculitis in Caucasians. Acute visual loss in one or both eyes is by far the most feared and irreversible complication of giant cell arteritis. This article reviews recent guidelines on early recognition of systemic, cranial, and ophthalmic manifestations, and current management and diagnostic strategies and advances in imaging. We share our experience of the fast track pathway and imaging in associated disorders, such as large-vessel vasculitis.

1.44-μm giant pulse generation

NASA Astrophysics Data System (ADS)

Šulc, Jan; Arátor, Pavel; Jelínková, Helena; Nejezchleb, Karel; Škoda, Václav

2007-02-01

We have compared two solid-state saturable absorbers for Q-switching of longitudinally diode-pumped Nd:YAG laser operating at wavelength 1444 nm: vanadium doped garnet (V 3+:Y 3Al IIO 5, V:YAG), and cobalt doped spinel (Co 2+:MgAl IIO 4, Co:MALO). V:YAG crystal with initial transmission 91% was 2.2mm thick. Co:MALO crystal with initial transmission 91% was 2.0mm thick. Q-switched laser consisted of the Nd:YAG composite rod (8mm long Nd-doped part, 4mm long undoped YAG part) and the saturable absorber placed in 80mm long hemispheric cavity. As an output coupler was used concave mirror (r = 150mm) with reflectivity 98% on lasing wavelength. Giant pulses were obtained with both passive Q-switches. When V:YAG saturable absorber was used, 55 ns long (FWHM) pulses were generated with peak power 0.47kW (pulse energy 26 μJ). Using Co:MALO, more powerful pulses were obtained (40 ns long, 1.0kW peak power, 45 μJ energy). Advantage of less efficient V:YAG consist in possibility of diffusion bonding between Q-switch and laser active medium which allows to prepare miniature compact laser device. This concept was demonstrated by using of Nd:YAG/V:YAG monolith crystal (4mm long undoped YAG part, 8mm long Nd:YAG part, 0.5mm long V:YAG part - initial transmission 97% @ 1444 nm). This monolithic crystal, originally designed for 1338nm lasing, was placed into 23mm long cavity resonating at wavelength 1444 nm. For output coupler reflectivity 96% pulses 39 ns long with peak power 0.64kW were generated at wavelength 1444 nm.

The size-line width relation and the mass of molecular hydrogen

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

Issa, M.; Maclaren, I.; Wolfendale, A. W.

Some difficulties associated with the problem of cloud definition are considered, with particular regard to the crowded distribution of clouds and the difficulty of choosing an appropriate boundary in such circumstances. A number of tests carried out on the original data suggest that the delta(v) - S relation found by Solomon et al. (1987) is not a genuine reflection of the dynamical state of Giant Molecular Clouds. The Solomon et al. parameters, are insensitive to the actual cloud properties and are unable to distinguish true clouds from the consequences of sampling any crowded region of emission down to a lowmore » threshold temperature. The overall effect of such problems is to overestimate both the masses of Giant Molecular Clouds and the number of very large clouds. 24 refs.« less

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.

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

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

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.

Coarse-grained molecular dynamics simulations for giant protein-DNA complexes

NASA Astrophysics Data System (ADS)

Takada, Shoji

Biomolecules are highly hierarchic and intrinsically flexible. Thus, computational modeling calls for multi-scale methodologies. We have been developing a coarse-grained biomolecular model where on-average 10-20 atoms are grouped into one coarse-grained (CG) particle. Interactions among CG particles are tuned based on atomistic interactions and the fluctuation matching algorithm. CG molecular dynamics methods enable us to simulate much longer time scale motions of much larger molecular systems than fully atomistic models. After broad sampling of structures with CG models, we can easily reconstruct atomistic models, from which one can continue conventional molecular dynamics simulations if desired. Here, we describe our CG modeling methodology for protein-DNA complexes, together with various biological applications, such as the DNA duplication initiation complex, model chromatins, and transcription factor dynamics on chromatin-like environment.

The atmospheres of earthlike planets after giant impact events

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

Lupu, R. E.; Freedman, Richard; Zahnle, Kevin

2014-03-20

It is now understood that the accretion of terrestrial planets naturally involves giant collisions, the moon-forming impact being a well-known example. In the aftermath of such collisions, the surface of the surviving planet is very hot and potentially detectable. Here we explore the atmospheric chemistry, photochemistry, and spectral signatures of post-giant-impact terrestrial planets enveloped by thick atmospheres consisting predominantly of CO{sub 2} and H{sub 2}O. The atmospheric chemistry and structure are computed self-consistently for atmospheres in equilibrium with hot surfaces with composition reflecting either the bulk silicate Earth (which includes the crust, mantle, atmosphere, and oceans) or Earth's continental crust.more » We account for all major molecular and atomic opacity sources including collision-induced absorption. We find that these atmospheres are dominated by H{sub 2}O and CO{sub 2}, while the formation of CH{sub 4} and NH{sub 3} is quenched because of short dynamical timescales. Other important constituents are HF, HCl, NaCl, and SO{sub 2}. These are apparent in the emerging spectra and can be indicative that an impact has occurred. The use of comprehensive opacities results in spectra that are a factor of two lower brightness temperature in the spectral windows than predicted by previous models. The estimated luminosities show that the hottest post-giant-impact planets will be detectable with near-infrared coronagraphs on the planned 30 m class telescopes. The 1-4 μm will be most favorable for such detections, offering bright features and better contrast between the planet and a potential debris disk. We derive cooling timescales on the order of 10{sup 5-6} yr on the basis of the modeled effective temperatures. This leads to the possibility of discovering tens of such planets in future surveys.« less

Blood Lead Levels in Captive Giant Pandas.

PubMed

Wintle, Nathan J P; Martin-Wintle, Meghan S; Zhou, Xiaoping; Zhang, Hemin

2018-01-01

Fifteen giant pandas (Ailuropoda melanoleuca) from the Chinese Conservation and Research Center for the Giant Panda (CCRCGP) in Bifengxia, Sichuan, China were analyzed for blood lead concentrations (Pb-B) during the 2017 breeding season. Thirteen of the 15 bears showed Pb-B below the method detection limit (MDL) of 3.3 µg/dL. The two remaining bears, although above the MDL, contained very low concentrations of lead of 3.9 and 4.5 µg/dL. All 15 giant pandas in this analysis had Pb-B concentrations that were within normal background concentrations for mammals in uncontaminated environments. For a threatened species, whose native country is plagued by reports of extremely high air pollution, our findings suggest that giant pandas at the CCRCGP are not absorbing lead at concentrations that would adversely affect their health.

Simultaneous above and below approach to giant pituitary adenomas: surgical strategies and long-term follow-up

PubMed Central

D’Ambrosio, Anthony L.; Grobelny, Bartosz T.; Freda, Pamela U.; Wardlaw, Sharon; Bruce, Jeffrey N.

2012-01-01

Introduction Giant pituitary adenomas of excessive size, fibrous consistency or unfavorable geometric configuration may be unresectable through conventional operative approaches. We present our select case series for operative resection and long-term follow-up for these unusual tumors, employing both a staged procedure and a combined transsphenoidal-transcranial above and below approach. Method A retrospective chart review was performed on patients operated via the staged, and combined approaches by the senior author (J.N·B.). Pre-operative characteristics and postoperative outcomes were reviewed. A detailed description of the operative technique and perioperative management is provided. Results Between 1993 and 1996, two patients harboring giant pituitary adenomas underwent an intentionally staged resection, and between 1997 and 2006, nine patients harboring giant pituitary adenomas underwent surgery via a single-stage above and below approach. Nine patients (82%) presented with non-secreting adenomas and two patients (18%) presented with prolactinomas refractory to medical management. Gross total resection was achieved in six patients (55%), near total resection in 1 (9%), and subtotal removal in 4 (36%). Seven patients (64%) experienced visual improvement postoperatively and no major complications occurred. Long-term follow-up averaged 51.6 months. Panhypopituitarism was observed in four patients, partial hypopituitarism in four, persistent DI in two, and persistent SIADH in one. Conclusions The addition of a transcranial component to the transsphenoidal approach offers additional visualization of critical neurovascular structures during giant pituitary adenoma resection. Complications rates are similar to other series in which complex pituitary adenomas are resected by other means. The above and below approach is both safe and effective and the immediate and long-term advantages of a single-stage approach justify its utility in this select group of patients

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.

Disappearance of the Supergiant Progenitor of SN 2011dh in M51

NASA Astrophysics Data System (ADS)

Van Dyk, Schuyler D.; Filippenko, Alexei V.; Fox, Ori; Kelly, Patrick; Smith, Nathan

2013-03-01

We report that in Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) observations at F555W and F814W with the UVIS channel, conducted on 2013 March 2 UT as part of our Cycle 20 Snapshot program GO-13029 (PI: A. Filippenko), we have discovered that the yellow supergiant star, identified by Van Dyk et al. (2011, ApJ, 741, L28) and Maund et al. (2011, MNRAS, 739, L37) at the position of the Type IIb SN 2011dh in M51, has vanished.

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.

Molecular phylogeny of the red panda (Ailurus fulgens).

PubMed

Slattery, J P; O'Brien, S J

1995-01-01

The phylogenetic placement of the red panda (Ailurus fulgens) and the giant panda (Ailuropoda melanoleuca) has been an evolutionary enigma since their original descriptions in the nineteenth century. A series of recent molecular analyses led to a consensus that the giant panda's ancestors were derived from early bears (Ursidae), but left unsettled the phylogenetic relationship of the red panda. Previous molecular and morphological phylogenies were inconclusive and varied among placement of the red panda within the raccoon family (Procyonidae), within the bear family (Ursidae), or in a separate family of carnivores equidistant between the two. To examine a relatively ancient (circa 20-30 million years before the present, MYBP) phylogenetic divergence, we used two slowly evolving genetic markers: mitochondrial 12S rRNA sequence and 592 fibroblast proteins resolved by two dimensional gel electrophoresis. Four different carnivore outgroup species, including dog (Canidae: Canis familiaris), cat (Felidae: Felis catus), fanaloka (Viverridae: Fossa fossa), and mongoose (Herpestidae: Galidia elegans), were selected to identify the root of the phylogenetic topologies. Phylogenetic reconstruction by distance-based methods, maximum parsimony, and maximum likelihood clearly indicate a distinct bifurcation forming the Ursidae and the Procyonidae. Further, our data consistently place the red panda as an early divergence within the Procyonidae radiation and confirm the inclusion of giant panda in the Ursidae lineage.

Molecular pathways underlying inhibitory effect of antimicrobial peptide Nal-P-113 on bacteria biofilms formation of Porphyromonas gingivalis W83 by DNA microarray.

PubMed

Wang, Hong-Yan; Lin, Li; Tan, Li-Si; Yu, Hui-Yuan; Cheng, Jya-Wei; Pan, Ya-Ping

2017-02-17

Wound-related infection remains a major challenge for health professionals. One disadvantage in conventional antibiotics is their inability to penetrate biofilms, the main protective strategy for bacteria to evade irradiation. Previously, we have shown that synthetic antimicrobial peptides could inhibit bacterial biofilms formation. In this study, we first delineated how Nal-P-113, a novel antimicrobial peptide, exerted its inhibitory effects on Porphyromonas gingivalis W83 biofilms formation at a low concentration. Secondly, we performed gene expression profiling and validated that Nal-P-113 at a low dose significantly down-regulated genes related to mobile and extrachromosomal element functions, transport and binding proteins in Porphyromonas gingivalis W83. These findings suggest that Nal-P-113 at low dose is sufficient to inhibit the formation of biofilms although Porphyromonas gingivalis W83 may maintain its survival in the oral cavity. The newly discovered molecular pathways may add the knowledge of developing a new strategy to target bacterial infections in combination with current first-line treatment in periodontitis.

Correlational Effects of the Molecular-Tilt Configuration and the Intermolecular van der Waals Interaction on the Charge Transport in the Molecular Junction.

PubMed

Shin, Jaeho; Gu, Kyungyeol; Yang, Seunghoon; Lee, Chul-Ho; Lee, Takhee; Jang, Yun Hee; Wang, Gunuk

2018-06-25

Molecular conformation, intermolecular interaction, and electrode-molecule contacts greatly affect charge transport in molecular junctions and interfacial properties of organic devices by controlling the molecular orbital alignment. Here, we statistically investigated the charge transport in molecular junctions containing self-assembled oligophenylene molecules sandwiched between an Au probe tip and graphene according to various tip-loading forces ( F L ) that can control the molecular-tilt configuration and the van der Waals (vdW) interactions. In particular, the molecular junctions exhibited two distinct transport regimes according to the F L dependence (i.e., F L -dependent and F L -independent tunneling regimes). In addition, the charge-injection tunneling barriers at the junction interfaces are differently changed when the F L ≤ 20 nN. These features are associated to the correlation effects between the asymmetry-coupling factor (η), the molecular-tilt angle (θ), and the repulsive intermolecular vdW force ( F vdW ) on the molecular-tunneling barriers. A more-comprehensive understanding of these charge transport properties was thoroughly developed based on the density functional theory calculations in consideration of the molecular-tilt configuration and the repulsive vdW force between molecules.

Giants among larges: how gigantism impacts giant virus entry into amoebae.

PubMed

Rodrigues, Rodrigo Araújo Lima; Abrahão, Jônatas Santos; Drumond, Betânia Paiva; Kroon, Erna Geessien

2016-06-01

The proposed order Megavirales comprises the nucleocytoplasmic large DNA viruses (NCLDV), infecting a wide range of hosts. Over time, they co-evolved with different host cells, developing various strategies to penetrate them. Mimiviruses and other giant viruses enter cells through phagocytosis, while Marseillevirus and other large viruses explore endocytosis and macropinocytosis. These differing strategies might reflect the evolution of those viruses. Various scenarios have been proposed for the origin and evolution of these viruses, presenting one of the most enigmatic issues to surround these microorganisms. In this context, we believe that giant viruses evolved independently by massive gene/size gain, exploring the phagocytic pathway of entry into amoebas. In response to gigantism, hosts developed mechanisms to evade these parasites. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mass loss from red giants - A simple evolutionary model for NGC 7027

NASA Technical Reports Server (NTRS)

Jura, M.

1984-01-01

NGC 7027 is a young planetary nebula with the remnants of a red giant circumstellar envelope surrounding the central, ionized region. By comparing the outer molecular envelope with the inner ionized material, it is argued that the mass loss rate has decreased by at least a factor of 3, and more probably by about a factor of 10, during the past 1000 years. From this result, it is argued that the luminosity of the central star has also decreased substantially during the same time, consistent with models for the rapid evolution of stars just after they evolve off the asymptotic giant branch. In this picture, the distance to NGC 7027 is less than 1300 pc. NGC 7027 was the last (and best) example of a star where apparently the momentum in the outflowing mass /M(dot)v/ is considerably greater than the momentum in the radiation field (L/c). With the above description of this object, the evidence is now strong that quite often the mass lost from late-type giants is ultimately driven to infinity by radiation pressure on grains. If M(dot)v is as large as L/c for asymptotic branch stars, then it is expected that the total amount of mass lost during this stage of evolution is of the same magnitude as the initial mass of the star, and therefore this mass loss can profoundly affect the star's ultimate fate.

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

Giant cell arteritis: a review

PubMed Central

Patil, Pravin; Karia, Niral; Jain, Shaifali; Dasgupta, Bhaskar

2013-01-01

Giant cell arteritis is the most common vasculitis in Caucasians. Acute visual loss in one or both eyes is by far the most feared and irreversible complication of giant cell arteritis. This article reviews recent guidelines on early recognition of systemic, cranial, and ophthalmic manifestations, and current management and diagnostic strategies and advances in imaging. We share our experience of the fast track pathway and imaging in associated disorders, such as large-vessel vasculitis. PMID:28539785

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.

Giant cell phlebitis: a potentially lethal clinical entity.

PubMed

Kunieda, Takeshige; Murayama, Masanori; Ikeda, Tsuneko; Yamakita, Noriyoshi

2012-08-01

An 83-year-old woman presented to us with a 4-week history of general malaise, subjective fever and lower abdominal pain. Despite the intravenous infusion of antibiotics, her blood results and physical condition worsened, resulting in her sudden death. Autopsy study revealed that the medium-sized veins of the mesentery were infiltrated by eosinophil granulocytes, lymphocytes, macrophages and multinucleated giant cells; however, the arteries were not involved. Microscopically, venous giant cell infiltration was observed in the gastrointestinal tract, bladder, retroperitoneal tissues and myocardium. The final diagnosis was giant cell phlebitis, a rare disease of unknown aetiology. This case demonstrates for the first time that giant cell phlebitis involving extra-abdominal organs, including hearts, can cause serious morbidity.

THE O- AND B-TYPE STELLAR POPULATION IN W3: BEYOND THE HIGH-DENSITY LAYER

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

Kiminki, Megan M.; Kim, Jinyoung Serena; Bagley, Micaela B.

2015-11-01

We present the first results from our survey of the star-forming complex W3, combining VRI photometry with multiobject spectroscopy to identify and characterize the high-mass stellar population across the region. With 79 new spectral classifications, we bring the total number of spectroscopically confirmed O- and B-type stars in W3 to 105. We find that the high-mass slope of the mass function in W3 is consistent with a Salpeter IMF, and that the extinction toward the region is best characterized by an R{sub V} of approximately 3.6. B-type stars are found to be more widely dispersed across the W3 giant molecularmore » cloud (GMC) than previously realized: they are not confined to the high-density layer (HDL) created by the expansion of the neighboring W4 H ii region into the GMC. This broader B-type population suggests that star formation in W3 began spontaneously up to 8–10 Myr ago, although at a lower level than the more recent star formation episodes in the HDL. In addition, we describe a method of optimizing sky subtraction for fiber spectra in regions of strong and spatially variable nebular emission.« less

GIANT MOLECULAR CLOUDS AND STAR FORMATION IN THE NON-GRAND DESIGN SPIRAL GALAXY NGC 6946

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

Rebolledo, David; Wong, Tony; Leroy, Adam

We present high spatial resolution observations of giant molecular clouds (GMCs) in the eastern part of the nearby spiral galaxy NGC 6946 obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We have observed CO(1 {yields} 0), CO(2 {yields} 1) and {sup 13}CO(1 {yields} 0), achieving spatial resolutions of 5.''4 Multiplication-Sign 5.''0, 2.''5 Multiplication-Sign 2.''0, and 5.''6 Multiplication-Sign 5.''4, respectively, over a region of 6 Multiplication-Sign 6 kpc. This region extends from 1.5 kpc to 8 kpc galactocentric radius, thus avoiding the intense star formation in the central kpc. We have recovered short-spacing u-v components by using singlemore » dish observations from the Nobeyama 45 m and IRAM 30 m telescopes. Using the automated CPROPS algorithm, we identified 45 CO cloud complexes in the CO(1 {yields} 0) map and 64 GMCs in the CO(2 {yields} 1) maps. The sizes, line widths, and luminosities of the GMCs are similar to values found in other extragalactic studies. We have classified the clouds into on-arm and inter-arm clouds based on the stellar mass density traced by the 3.6 {mu}m map. Clouds located on-arm present in general higher star formation rates than clouds located in inter-arm regions. Although the star formation efficiency shows no systematic trend with galactocentric radius, some on-arm clouds-which are more luminous and more massive compared to inter-arm GMCs-are also forming stars more efficiently than the rest of the identified GMCs. We find that these structures appear to be located in two specific regions in the spiral arms. One of them shows a strong velocity gradient, suggesting that this region of high star formation efficiency may be the result of gas flow convergence.« less

FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN): Molecular clouds toward W 33; possible evidence for a cloud-cloud collision triggering O star formation

NASA Astrophysics Data System (ADS)

Kohno, Mikito; Torii, Kazufumi; Tachihara, Kengo; Umemoto, Tomofumi; Minamidani, Tetsuhiro; Nishimura, Atsushi; Fujita, Shinji; Matsuo, Mitsuhiro; Yamagishi, Mitsuyoshi; Tsuda, Yuya; Kuriki, Mika; Kuno, Nario; Ohama, Akio; Hattori, Yusuke; Sano, Hidetoshi; Yamamoto, Hiroaki; Fukui, Yasuo

2018-01-01

We observed molecular clouds in the W 33 high-mass star-forming region associated with compact and extended H II regions using the NANTEN2 telescope as well as the Nobeyama 45 m telescope in the J = 1-0 transitions of 12CO, 13CO, and C18O as part of the FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN) legacy survey. We detected three velocity components at 35 km s-1, 45 km s-1, and 58 km s-1. The 35 km s-1 and 58 km s-1 clouds are likely to be physically associated with W 33 because of the enhanced 12CO J = 3-2 to J = 1-0 intensity ratio as R3-2/1-0 > 1.0 due to the ultraviolet irradiation by OB stars, and morphological correspondence between the distributions of molecular gas and the infrared and radio continuum emissions excited by high-mass stars. The two clouds show complementary distributions around W 33. The velocity separation is too large to be gravitationally bound, and yet not explained by expanding motion by stellar feedback. Therefore, we discuss whether a cloud-cloud collision scenario likely explains the high-mass star formation in W 33.

FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN): Molecular clouds toward W 33; possible evidence for a cloud-cloud collision triggering O star formation

NASA Astrophysics Data System (ADS)

Kohno, Mikito; Torii, Kazufumi; Tachihara, Kengo; Umemoto, Tomofumi; Minamidani, Tetsuhiro; Nishimura, Atsushi; Fujita, Shinji; Matsuo, Mitsuhiro; Yamagishi, Mitsuyoshi; Tsuda, Yuya; Kuriki, Mika; Kuno, Nario; Ohama, Akio; Hattori, Yusuke; Sano, Hidetoshi; Yamamoto, Hiroaki; Fukui, Yasuo

2018-05-01

We observed molecular clouds in the W 33 high-mass star-forming region associated with compact and extended H II regions using the NANTEN2 telescope as well as the Nobeyama 45 m telescope in the J = 1-0 transitions of 12CO, 13CO, and C18O as part of the FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN) legacy survey. We detected three velocity components at 35 km s-1, 45 km s-1, and 58 km s-1. The 35 km s-1 and 58 km s-1 clouds are likely to be physically associated with W 33 because of the enhanced 12CO J = 3-2 to J = 1-0 intensity ratio as R_3-2/1-0} > 1.0 due to the ultraviolet irradiation by OB stars, and morphological correspondence between the distributions of molecular gas and the infrared and radio continuum emissions excited by high-mass stars. The two clouds show complementary distributions around W 33. The velocity separation is too large to be gravitationally bound, and yet not explained by expanding motion by stellar feedback. Therefore, we discuss whether a cloud-cloud collision scenario likely explains the high-mass star formation in W 33.

Amino acid composition and functional properties of giant red sea cucumber ( Parastichopus californicus) collagen hydrolysates

NASA Astrophysics Data System (ADS)

Liu, Zunying; Su, Yicheng; Zeng, Mingyong

2011-03-01

Giant red sea cucumber ( Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis. The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species. The degree of hydrolysis (DH), amino acid composition, SDS-PAGE, emulsion activity index (EAI), emulsion stability index (ESI), foam expansion (FE), and foam stability (FS) of hydrolysates were investigated. The effects of pH on the EAI, ESI FE and FS of hydrolysates were also investigated. The results indicated that the β and α 1 chains of the collagen were effectively hydrolyzed by trypsin at 50°c with an Enzyme/Substrate (E/S) ration of 1:20 (w:w). The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin. The hydrolysates had a molecular weight distribution of 1.1-17 kDa, and were abundant in glycine (Gly), proline (Pro), glutamic acid (Glu), alanine (Ala) and hydroxyproline (Hyp) residues. The hydrolysates were fractionated into three fractions (< 3 kDa, 3-10 kDa, and > 10 kDa), and the fraction of 3-10 kDa exhibited a higher EAI value than the fraction of > 10 kDa ( P<0.05). The fraction of > 10 kDa had higher FE and FS values than other fractions ( P<0.05). The pH had an important effect on the EAI, ESI, FE and FS. All the fractions showed undesirable emulsion and forming properties at pH 4.0. Under pH 7.0 and pH 10.0, the 3-10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value, respectively. They are hoped to be utilized as functional ingredients in food and nutraceutical industries.

Mass loss in red giants and supergiants

NASA Technical Reports Server (NTRS)

Sanner, F.

1975-01-01

The circumstellar envelopes surrounding late-type giants and supergiants were studied using high resolution, photoelectric scans of strong optical resonance lines. A method for extracting the circumstellar from the stellar components of the lines allowed a quantitative determination of the physical conditions in the envelopes and the rates of mass loss at various positions in the red giant region of the HR diagram. The observed strengthening of the circumstellar spectrum with increasing luminosity and later spectral type is probably caused by an increase in the mass of the envelopes. The mass loss rate for individual stars is proportional to the visual luminosity; high rates for the supergiants suggest that mass loss is important in their evolution. The bulk of the mass return to the interstellar medium in the red giant region comes from the normal giants, at a rate comparable to that of planetary nebulae.

Formation of Giant Planets and Brown Dwarves

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.

2003-01-01

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 planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Models predict that rocky planets should form in orbit about most stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. Ongoing theoretical modeling of accretion of giant planet atmospheres, as well as observations of protoplanetary disks, will help decide this issue. Observations of extrasolar planets around main sequence stars can only provide a lower limit on giant planet formation frequency . This is because after giant planets form, gravitational interactions with material within the protoplanetary disk may cause them to migrat inwards and be lost to the central star. The core instability model can only produce planets greater than a few jovian masses within protoplanetary disks that are more viscous than most such disks are believed to be. Thus, few brown dwarves (objects massive enough to undergo substantial deuterium fusion, estimated to occur above approximately 13 jovian masses) are likely to be formed in this manner. Most brown dwarves, as well as an unknown number of free-floating objects of planetary mass, are probably formed as are stars, by the collapse of extended gas/dust clouds into more compact objects.

Sequence-Mandated, Distinct Assembly of Giant Molecules

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

Zhang, Wei; Lu, Xinlin; Mao, Jialin

Although controlling the primary structure of synthetic polymers is itself a great challenge, the potential of sequence control for tailoring hierarchical structures remains to be exploited, especially in the creation of new and unconventional phases. A series of model amphiphilic chain-like giant molecules was designed and synthesized by interconnecting both hydrophobic and hydrophilic molecular nanoparticles in precisely defined sequence and composition to investigate their sequence-dependent phase structures. Not only compositional variation changed the self-assembled supramolecular phases, but also specific sequences induce unconventional phase formation, including Frank-Kasper phases. The formation mechanism was attributed to the conformational change driven by the collectivemore » hydrogen bonding and the sequence-mandated topology of the molecules. Lastly, these results show that sequence control in synthetic polymers can have a dramatic impact on polymer properties and self-assembly.« less

Sequence-Mandated, Distinct Assembly of Giant Molecules

DOE PAGES

Zhang, Wei; Lu, Xinlin; Mao, Jialin; ...

2017-10-24

Although controlling the primary structure of synthetic polymers is itself a great challenge, the potential of sequence control for tailoring hierarchical structures remains to be exploited, especially in the creation of new and unconventional phases. A series of model amphiphilic chain-like giant molecules was designed and synthesized by interconnecting both hydrophobic and hydrophilic molecular nanoparticles in precisely defined sequence and composition to investigate their sequence-dependent phase structures. Not only compositional variation changed the self-assembled supramolecular phases, but also specific sequences induce unconventional phase formation, including Frank-Kasper phases. The formation mechanism was attributed to the conformational change driven by the collectivemore » hydrogen bonding and the sequence-mandated topology of the molecules. Lastly, these results show that sequence control in synthetic polymers can have a dramatic impact on polymer properties and self-assembly.« less

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.

Theoretical study of the dielectronic recombination process of Li-like Xe51+ ions

NASA Astrophysics Data System (ADS)

Dou, Lijun; Xie, Luyou; Zhang, Denghong; Dong, Chenzhong; Wen, Weiqiang; Huang, Zhongkui; Ma, Xinwen

2017-05-01

The dielectronic recombination of Li-like Xe51+ (2s) ions was studied using the flexible atomic code based on the relativistic configuration interaction method. The resonance energies, radiative and autoionization rates, and resonance strengths were calculated systematically for the doubly excited states (2p1/2nlj)J(n = 18-32) and (2p3/2n'lj)J(n' = 9-27) of Be-like Xe50+ ions. For the higher Rydberg resonance states with n ≥ 33 and n' ≥ 28, the resonance energies and strengths were obtained by extrapolation based on quantum defect theory. The theoretical rate coefficients, covering the center-of-mass energy range 0-505 eV, are in a better agreement with the experimental results measured at the heavy-ion storage ring ESR than the Multi-Configuration Dirac-Fock calculations, especially at the resonance energy range close to the series limits. Contribution to the Topical Issue: "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, Grzegorz Karwasz.

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

Molecular Modeling and Structural Stability of Wild-Type and Mutant CYP51 from Leishmania major: In Vitro and In Silico Analysis of a Laboratory Strain.

PubMed

Keighobadi, Masoud; Emami, Saeed; Lagzian, Milad; Fakhar, Mahdi; Rafiei, Alireza; Valadan, Reza

2018-03-19

Cutaneous leishmaniasis is a neglected tropical disease and a major public health in the most countries. Leishmania major is the most common cause of cutaneous leishmaniasis. In the Leishmania parasites, sterol 14α-demethylase (CYP51), which is involved in the biosynthesis of sterols, has been identified as an attractive target for development of new therapeutic agents. In this study, the sequence and structure of CYP51 in a laboratory strain (MRHO/IR/75/ER) of L. major were determined and compared to the wild-type strain. The results showed 19 mutations including seven non-synonymous and 12 synonymous ones in the CYP51 sequence of strain MRHO/IR/75/ER. Importantly, an arginine to lysine substitution at position of 474 resulted in destabilization of CYP51 (ΔΔG = 1.17 kcal/mol) in the laboratory strain; however, when the overall effects of all substitutions were evaluated by 100 ns molecular dynamics simulation, the final structure did not show any significant changes ( p -value < 0.05) in stability parameter of the strain MRHO/IR/75/ER compared to the wild-type protein. The energy level for the CYP51 of wild-type and MRHO/IR/75/ER strain were -40,027.1 and -39,706.48 Kcal/mol respectively. The overall Root-mean-square deviation (RMSD) deviation between two proteins was less than 1 Å throughout the simulation and Root-mean-square fluctuation (RMSF) plot also showed no substantial differences between amino acids fluctuation of the both protein. The results also showed that, these mutations were located on the protein periphery that neither interferes with protein folding nor with substrate/inhibitor binding. Therefore, L. major strain MRHO/IR/75/ER is suggested as a suitable laboratory model for studying biological role of CYP51 and inhibitory effects of sterol 14α-demethylase inhibitors.

Srs2 prevents Rad51 filament formation by repetitive motion on DNA.

PubMed

Qiu, Yupeng; Antony, Edwin; Doganay, Sultan; Koh, Hye Ran; Lohman, Timothy M; Myong, Sua

2013-01-01

Srs2 dismantles presynaptic Rad51 filaments and prevents its re-formation as an anti-recombinase. However, the molecular mechanism by which Srs2 accomplishes these tasks remains unclear. Here we report a single-molecule fluorescence study of the dynamics of Rad51 filament formation and its disruption by Srs2. Rad51 forms filaments on single-stranded DNA by sequential binding of primarily monomers and dimers in a 5'-3' direction. One Rad51 molecule binds to three nucleotides, and six monomers are required to achieve a stable nucleation cluster. Srs2 exhibits ATP-dependent repetitive motion on single-stranded DNA and this activity prevents re-formation of the Rad51 filament. The same activity of Srs2 cannot prevent RecA filament formation, indicating its specificity for Rad51. Srs2's DNA-unwinding activity is greatly suppressed when Rad51 filaments form on duplex DNA. Taken together, our results reveal an exquisite and highly specific mechanism by which Srs2 regulates the Rad51 filament formation.

Giant cell phlebitis: a potentially lethal clinical entity

PubMed Central

Kunieda, Takeshige; Murayama, Masanori; Ikeda, Tsuneko; Yamakita, Noriyoshi

2012-01-01

An 83-year-old woman presented to us with a 4-week history of general malaise, subjective fever and lower abdominal pain. Despite the intravenous infusion of antibiotics, her blood results and physical condition worsened, resulting in her sudden death. Autopsy study revealed that the medium-sized veins of the mesentery were infiltrated by eosinophil granulocytes, lymphocytes, macrophages and multinucleated giant cells; however, the arteries were not involved. Microscopically, venous giant cell infiltration was observed in the gastrointestinal tract, bladder, retroperitoneal tissues and myocardium. The final diagnosis was giant cell phlebitis, a rare disease of unknown aetiology. This case demonstrates for the first time that giant cell phlebitis involving extra-abdominal organs, including hearts, can cause serious morbidity. PMID:22859384

Molecular complexes in close and far away

PubMed Central

Klemperer, William; Vaida, Veronica

2006-01-01

In this review, gas-phase chemistry of interstellar media and some planetary atmospheres is extended to include molecular complexes. Although the composition, density, and temperature of the environments discussed are very different, molecular complexes have recently been considered as potential contributors to chemistry. The complexes reviewed include strongly bound aggregates of molecules with ions, intermediate-strength hydrogen bonded complexes (primarily hydrates), and weakly bonded van der Waals molecules. In low-density, low-temperature environments characteristic of giant molecular clouds, molecular synthesis, known to involve gas-phase ion-molecule reactions and chemistry at the surface of dust and ice grains is extended here to involve molecular ionic clusters. At the high density and high temperatures found on planetary atmospheres, molecular complexes contribute to both atmospheric chemistry and climate. Using the observational, laboratory, and theoretical database, the role of molecular complexes in close and far away is discussed. PMID:16740667

Exotic Earths: forming habitable worlds with giant planet migration.

PubMed

Raymond, Sean N; Mandell, Avi M; Sigurdsson, Steinn

2006-09-08

Close-in giant planets (e.g., "hot Jupiters") are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered "hot Earths." Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets.

Resolved Giant Molecular Clouds in Nearby Spiral Galaxies: Insights from the CANON CO (1-0) Survey

NASA Astrophysics Data System (ADS)

Donovan Meyer, Jennifer; Koda, Jin; Momose, Rieko; Mooney, Thomas; Egusa, Fumi; Carty, Misty; Kennicutt, Robert; Kuno, Nario; Rebolledo, David; Sawada, Tsuyoshi; Scoville, Nick; Wong, Tony

2013-08-01

We resolve 182 individual giant molecular clouds (GMCs) larger than 2.5 × 105 M ⊙ in the inner disks of 5 large nearby spiral galaxies (NGC 2403, NGC 3031, NGC 4736, NGC 4826, and NGC 6946) to create the largest such sample of extragalactic GMCs within galaxies analogous to the Milky Way. Using a conservatively chosen sample of GMCs most likely to adhere to the virial assumption, we measure cloud sizes, velocity dispersions, and 12CO (J = 1-0) luminosities and calculate cloud virial masses. The average conversion factor from CO flux to H2 mass (or X CO) for each galaxy is 1-2 × 1020 cm-2 (K km s-1)-1, all within a factor of two of the Milky Way disk value (~2 × 1020 cm-2 (K km s-1)-1). We find GMCs to be generally consistent within our errors between the galaxies and with Milky Way disk GMCs; the intrinsic scatter between clouds is of order a factor of two. Consistent with previous studies in the Local Group, we find a linear relationship between cloud virial mass and CO luminosity, supporting the assumption that the clouds in this GMC sample are gravitationally bound. We do not detect a significant population of GMCs with elevated velocity dispersions for their sizes, as has been detected in the Galactic center. Though the range of metallicities probed in this study is narrow, the average conversion factors of these galaxies will serve to anchor the high metallicity end of metallicity-X CO trends measured using conversion factors in resolved clouds; this has been previously possible primarily with Milky Way measurements.

Giant cell angiofibroma or localized periorbital lymphedema?

PubMed

Lynch, Michael C; Chung, Catherine G; Specht, Charles S; Wilkinson, Michael; Clarke, Loren E

2013-12-01

Giant cell angiofibroma represents a rare soft tissue neoplasm with a predilection for the orbit. We recently encountered a mass removed from the lower eyelid of a 56-year-old female that histopathologically resembled giant cell angiofibroma. The process consisted of haphazardly arranged CD34-positive spindled and multinucleated cells within an edematous, densely vascular stroma. However, the patient had recently undergone laryngectomy and radiotherapy for a laryngeal squamous cell carcinoma. A similar mass had arisen on the contralateral eyelid, and both had developed several months post-therapy. Lymphedema of the orbit can present as tumor-like nodules and in some cases may share histopathologic features purported to be characteristic of giant cell angiofibroma. A relationship between giant cell angiofibroma and lymphedema has not been established, but our case suggests there may be one. The potential overlap of these two conditions should be recognized, as should other entities that may enter the differential diagnosis. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Tissular expansion in giant congenital nevi treatment].

PubMed

Nguyen Van Nuoi, V; Francois-Fiquet, C; Diner, P; Sergent, B; Zazurca, F; Franchi, G; Buis, J; Vazquez, M-P; Picard, A; Kadlub, N

2014-08-01

Surgical management of giant melanotic naevi remains a surgical challenge. Tissue expansion provides tissue of the same quality for the repair of defects. The aim of this study is to review tissular expansion for giant melanotic naevi. We conducted a retrospective study from 2000 to 2012. All children patients who underwent a tissular expansion for giant congenital naevi had been included. Epidemiological data, surgical procedure, complication rate and results had been analysed. Thirty-tree patients had been included; they underwent 61 procedures with 79 tissular-expansion prosthesis. Previous surgery, mostly simple excision had been performed before tissular expansion. Complete naevus excision had been performed in 63.3% of the cases. Complications occurred in 45% of the cases, however in 50% of them were minor. Iterative surgery increased the complication rate. Tissular expansion is a valuable option for giant congenital naevus. However, complication rate remained high, especially when iterative surgery is needed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

[Giant paraovarian cyst in childhood - Case report].

PubMed

Torres, Janina P; Íñiguez, Rodrigo D

2015-01-01

Paraovarian cysts are very uncommon in children To present a case of giant paraovarian cyst case in a child and its management using a modified laparoscopic-assisted technique A 13-year-old patient with a 15 day-history of intermittent abdominal pain, located in the left hemiabdomen and associated with progressive increase in abdominal volume. Diagnostic imaging was inconclusive, describing a giant cystic formation that filled up the abdomen, but without specifying its origin. Laboratory tests and tumor markers were within normal range. Video-assisted transumbilical cystectomy, a modified laparoscopic procedure with diagnostic and therapeutic intent, was performed with a successful outcome. The histological study reported giant paraovarian cyst. Cytology results were negative for tumor cells. The patient remained asymptomatic during the postoperative follow-up. The video-assisted transumbilical cystectomy is a safe procedure and an excellent diagnostic and therapeutic alternative for the treatment of giant paraovarian cysts. Copyright © 2015. Publicado por Elsevier España, S.L.U.

[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.

40 CFR 51.1101 - Applicability of part 51.

Code of Federal Regulations, 2014 CFR

2014-07-01

... provisions in subparts A-X of part 51 apply to areas for purposes of the 2008 NAAQS to the extent they are... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Applicability of part 51. 51.1101 Section 51.1101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 51.1101 - Applicability of part 51.

Code of Federal Regulations, 2013 CFR

2013-07-01

... provisions in subparts A-X of part 51 apply to areas for purposes of the 2008 NAAQS to the extent they are... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Applicability of part 51. 51.1101 Section 51.1101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 51.1101 - Applicability of part 51.

Code of Federal Regulations, 2012 CFR

2012-07-01

... provisions in subparts A-X of part 51 apply to areas for purposes of the 2008 NAAQS to the extent they are... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Applicability of part 51. 51.1101 Section 51.1101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

Exploring the Ice Giants with JWST

NASA Astrophysics Data System (ADS)

Orton, Glenn S.; Fletcher, Leigh; Hammel, Heidi B.; Melin, Henrik; Guerlet, Sandrine; Greathouse, Thomas K.; Irwin, Patrick GJ

2017-06-01

The Ice Giants Uranus and Neptune are among the least-explored environments in our Solar System, having been visited only once, by Voyager 2 in 1986 and 1989, respectively. Their bulk properties and composition, intermediate between the hydrogen-rich gas giants and the smaller terrestrial worlds, make them representative of a planetary class that may be commonplace in other planetary systems. Furthermore, their small angular diameter, low atmospheric temperatures, and dynamic and ever-changing atmospheres make them tantalising infrared targets for JWST. This presentation will reveal the scientific rationale and requirements for a long-term program of JWST spectroscopic mapping of these two worlds. Specifically, the MIRI instrument can be used to determine the 3-dimensional temperature structure to understand (i) seasonal atmospheric circulation from the equator to the poles, (ii) the relation between temperatures, visible atmospheric banding and storm phenomena; and (iii) to discover the unknown circulations and wave phenomena shaping their middle atmospheres. JWST spectra will also allow us to search for and map chemical species produced from photochemistry (e.g., hydrocarbons derived from methane photolysis), from vertical mixing (e.g., disequilibrium species), and from external sources (e.g., HCN and oxygen compounds delivered by comets, ring rain and interplanetary dust). Furthermore, near-infrared imaging and spectroscopy with NIRCAM and NIRSpec will provide detailed characterisations of ice-giant cloud and haze formation and their evolution with time, as well as revealing how auroral processes (observed via H3+ emission) influence the middle atmosphere. JWST will not only enable intercomparison of these atmospheric processes on two very different worlds (Uranus with its extreme tilt and sluggish mixing; Neptune with its powerful internal heat source), but also mature our understanding of how ice giant phenomena compare to both gas giant and terrestrial

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

Probing the cold and warm molecular gas in the Whirlpool Galaxy: Herschel SPIRE-FTS observations of the central region of M51 (NGC 5194)

NASA Astrophysics Data System (ADS)

Schirm, M. R. P.; Wilson, C. D.; Kamenetzky, J.; Parkin, T. J.; Glenn, J.; Maloney, P.; Rangwala, N.; Spinoglio, L.; Baes, M.; Boselli, A.; Cooray, A.; De Looze, I.; Fernández-Ontiveros, J. A.; Karczewski, O. Ł.; Wu, R.

2017-10-01

We present Herschel Spectral and Photometric Imaging Receiver (SPIRE)-Fourier Transform Spectrometer (FTS) intermediate-sampled mapping observations of the central ˜8 kpc (˜150 arcsec) of M51, with a spatial resolution of 40 arcsec. We detect four 12CO transitions (J = 4-3 to J = 7-6) and the [C I] 3P2-3P1 and 3P1-3P0 transitions. We supplement these observations with ground-based observations of 12CO J = 1-0 to J = 3-2 and perform a two-component non-local thermodynamic equilibrium analysis. We find that the molecular gas in the nucleus and centre regions has a cool component (Tkin ˜ 10-20 K) with a moderate but poorly constrained density (n(H2) ˜ 103-106 cm-3), as well as significant molecular gas in a warmer (Tkin ˜ 300-3000 K), lower density (n(H2) ˜ 101.6-102.5 cm-3) component. We compare our CO line ratios and calculated densities along with ratios of CO to total infrared luminosity to a grid of photon-dominated region (PDR) models and find that the cold molecular gas likely resides in PDRs with a field strength of G0 ˜ 102. The warm component likely requires an additional source of mechanical heating, from supernovae and stellar winds or possibly shocks produced in the strong spiral density wave. When compared to similar two-component models of other star-forming galaxies published as part of the Very Nearby Galaxies Survey (Arp 220, M82 and NGC 4038/39), M51 has the lowest density for the warm component, while having a warm gas mass fraction that is comparable to those of Arp 220 and M82, and significantly higher than that of NGC 4038/39.

RE-INFLATED WARM JUPITERS AROUND RED GIANTS

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

Lopez, Eric D.; Fortney, Jonathan J.

2016-02-10

Since the discovery of the first transiting hot Jupiters, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of hot Jupiter radius anomalies scales strongly with a planet's level of irradiation and numerous models like tidal heating, ohmic dissipation, and thermal tides have since been developed to help explain these inflated radii. In general, however, these models can be grouped into two broad categories: models that directly inflate planetary radii by depositing a fraction of the incident irradiation into the interior and models that simply slow a planet's radiativemore » cooling, allowing it to retain more heat from formation and thereby delay contraction. Here we present a new test to distinguish between these two classes of models. Gas giants orbiting at moderate orbital periods around post-main-sequence stars will experience enormous increases to their irradiation as their host stars move up the sub-giant and red-giant branches. If hot Jupiter inflation works by depositing irradiation into the planet's deep interiors then planetary radii should increase in response to the increased irradiation. This means that otherwise non-inflated gas giants at moderate orbital periods of >10 days can re-inflate as their host stars evolve. Here we explore the circumstances that can lead to the creation of these “re-inflated” gas giants and examine how the existence or absence of such planets can be used to place unique constraints on the physics of the hot Jupiter inflation mechanism. Finally, we explore the prospects for detecting this potentially important undiscovered population of planets.« less

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.

The Distance to M51

NASA Astrophysics Data System (ADS)

McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

2016-07-01

Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive 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.

Giant Exoplanet and Debris Disk (Artist's Concept)

NASA Image and Video Library

2017-10-11

This artist's rendering shows a giant exoplanet causing small bodies to collide in a disk of dust. A study in The Astronomical Journal finds that giant exoplanets with long-period orbits are more likely to be found around young stars that have a disk of dust and debris than those without disks. The study focused on planets more than five times the mass of Jupiter. The astronomers are conducting the largest survey to date of stars with dusty debris disks, and finding the best evidence yet that giant planets are responsible for keeping that material in check. https://photojournal.jpl.nasa.gov/catalog/PIA22082

Are Strong Zonal Winds in Giant Planets Caused by Density-Stratification?

NASA Astrophysics Data System (ADS)

Verhoeven, J.; Stellmach, S.

2012-12-01

suggested mechanisms for driving differential rotation. Gary A. Glatzmaier, Martha Evonuk and Tamara M. Rogers (2009), Differential rotation in giant planets maintained by density-stratified turbulent convection. Geophysical and Astrophysical Fluid Dynamics, Vol. 103, No. 1, 31-51.

An ultrahot gas-giant exoplanet with a stratosphere.

PubMed

Evans, Thomas M; Sing, David K; Kataria, Tiffany; Goyal, Jayesh; Nikolov, Nikolay; Wakeford, Hannah R; Deming, Drake; Marley, Mark S; Amundsen, David S; Ballester, Gilda E; Barstow, Joanna K; Ben-Jaffel, Lotfi; Bourrier, Vincent; Buchhave, Lars A; Cohen, Ofer; Ehrenreich, David; García Muñoz, Antonio; Henry, Gregory W; Knutson, Heather; Lavvas, Panayotis; Etangs, Alain Lecavelier des; Lewis, Nikole K; López-Morales, Mercedes; Mandell, Avi M; Sanz-Forcada, Jorge; Tremblin, Pascal; Lupu, Roxana

2017-08-02

Infrared radiation emitted from a planet contains information about the chemical composition and vertical temperature profile of its atmosphere. If upper layers are cooler than lower layers, molecular gases will produce absorption features in the planetary thermal spectrum. Conversely, if there is a stratosphere-where temperature increases with altitude-these molecular features will be observed in emission. It has been suggested that stratospheres could form in highly irradiated exoplanets, but the extent to which this occurs is unresolved both theoretically and observationally. A previous claim for the presence of a stratosphere remains open to question, owing to the challenges posed by the highly variable host star and the low spectral resolution of the measurements. Here we report a near-infrared thermal spectrum for the ultrahot gas giant WASP-121b, which has an equilibrium temperature of approximately 2,500 kelvin. Water is resolved in emission, providing a detection of an exoplanet stratosphere at 5σ confidence. These observations imply that a substantial fraction of incident stellar radiation is retained at high altitudes in the atmosphere, possibly by absorbing chemical species such as gaseous vanadium oxide and titanium oxide.

An ultrahot gas-giant exoplanet with a stratosphere

NASA Astrophysics Data System (ADS)

Evans, Thomas M.; Sing, David K.; Kataria, Tiffany; Goyal, Jayesh; Nikolov, Nikolay; Wakeford, Hannah R.; Deming, Drake; Marley, Mark S.; Amundsen, David S.; Ballester, Gilda E.; Barstow, Joanna K.; Ben-Jaffel, Lotfi; Bourrier, Vincent; Buchhave, Lars A.; Cohen, Ofer; Ehrenreich, David; García Muñoz, Antonio; Henry, Gregory W.; Knutson, Heather; Lavvas, Panayotis; Lecavelier Des Etangs, Alain; Lewis, Nikole K.; López-Morales, Mercedes; Mandell, Avi M.; Sanz-Forcada, Jorge; Tremblin, Pascal; Lupu, Roxana

2017-08-01

Infrared radiation emitted from a planet contains information about the chemical composition and vertical temperature profile of its atmosphere. If upper layers are cooler than lower layers, molecular gases will produce absorption features in the planetary thermal spectrum. Conversely, if there is a stratosphere—where temperature increases with altitude—these molecular features will be observed in emission. It has been suggested that stratospheres could form in highly irradiated exoplanets, but the extent to which this occurs is unresolved both theoretically and observationally. A previous claim for the presence of a stratosphere remains open to question, owing to the challenges posed by the highly variable host star and the low spectral resolution of the measurements. Here we report a near-infrared thermal spectrum for the ultrahot gas giant WASP-121b, which has an equilibrium temperature of approximately 2,500 kelvin. Water is resolved in emission, providing a detection of an exoplanet stratosphere at 5σ confidence. These observations imply that a substantial fraction of incident stellar radiation is retained at high altitudes in the atmosphere, possibly by absorbing chemical species such as gaseous vanadium oxide and titanium oxide.

The young star cluster population of M51 with LEGUS - II. Testing environmental dependences

NASA Astrophysics Data System (ADS)

Messa, Matteo; Adamo, A.; Calzetti, D.; Reina-Campos, M.; Colombo, D.; Schinnerer, E.; Chandar, R.; Dale, D. A.; Gouliermis, D. A.; Grasha, K.; Grebel, E. K.; Elmegreen, B. G.; Fumagalli, M.; Johnson, K. E.; Kruijssen, J. M. D.; Östlin, G.; Shabani, F.; Smith, L. J.; Whitmore, B. C.

2018-06-01

It has recently been established that the properties of young star clusters (YSCs) can vary as a function of the galactic environment in which they are found. We use the cluster catalogue produced by the Legacy Extragalactic UV Survey (LEGUS) collaboration to investigate cluster properties in the spiral galaxy M51. We analyse the cluster population as a function of galactocentric distance and in arm and inter-arm regions. The cluster mass function exhibits a similar shape at all radial bins, described by a power law with a slope close to -2 and an exponential truncation around 105 M⊙. While the mass functions of the YSCs in the spiral arm and inter-arm regions have similar truncation masses, the inter-arm region mass function has a significantly steeper slope than the one in the arm region, a trend that is also observed in the giant molecular cloud mass function and predicted by simulations. The age distribution of clusters is dependent on the region considered, and is consistent with rapid disruption only in dense regions, while little disruption is observed at large galactocentric distances and in the inter-arm region. The fraction of stars forming in clusters does not show radial variations, despite the drop in the H2 surface density measured as a function of galactocentric distance. We suggest that the higher disruption rate observed in the inner part of the galaxy is likely at the origin of the observed flat cluster formation efficiency radial profile.

Giant Cells of Escherichia coli

PubMed Central

Adler, Howard I.; Terry, Claude E.; Hardigree, Alice A.

1968-01-01

A mutant strain of Escherichia coli K-12 produced amorphous cells when grown in a variety of media. The lon− allele, known to increase the radiation sensitivity of the cytokinesis mechanism, was introduced into the mutant by means of conjugation. Cells of this recombinant strain grew, after exposure to radiation, into giant amorphous cells, approximately 500 to 1,000 times the volume of a normal E. coli cell. These giant cells are analogous to the filaments formed after the irradiation of lon− rod-shaped cells. Images PMID:4866096

Dust ablation on the giant planets: Consequences for stratospheric photochemistry

NASA Astrophysics Data System (ADS)

Moses, Julianne I.; Poppe, Andrew R.

2017-11-01

Ablation of interplanetary dust supplies oxygen to the upper atmospheres of Jupiter, Saturn, Uranus, and Neptune. Using recent dynamical model predictions for the dust influx rates to the giant planets (Poppe et al., 2016), we calculate the ablation profiles and investigate the subsequent coupled oxygen-hydrocarbon neutral photochemistry in the stratospheres of these planets. We find that dust grains from the Edgeworth-Kuiper Belt, Jupiter-family comets, and Oort-cloud comets supply an effective oxygen influx rate of 1.0-0.7+2.2 ×107 O atoms cm-2 s-1 to Jupiter, 7.4-5.1+16 ×104 cm-2 s-1 to Saturn, 8.9-6.1+19 ×104 cm-2 s-1 to Uranus, and 7.5-5.1+16 ×105 cm-2 s-1 to Neptune. The fate of the ablated oxygen depends in part on the molecular/atomic form of the initially delivered products, and on the altitude at which it was deposited. The dominant stratospheric products are CO, H2O, and CO2, which are relatively stable photochemically. Model-data comparisons suggest that interplanetary dust grains deliver an important component of the external oxygen to Jupiter and Uranus but fall far short of the amount needed to explain the CO abundance currently seen in the middle stratospheres of Saturn and Neptune. Our results are consistent with the theory that all of the giant planets have experienced large cometary impacts within the last few hundred years. Our results also suggest that the low background H2O abundance in Jupiter's stratosphere is indicative of effective conversion of meteoric oxygen to CO during or immediately after the ablation process - photochemistry alone cannot efficiently convert the H2O into CO on the giant planets.

Giant retroperitoneal dedifferentiated liposarcoma.

PubMed

Beksac, Kemal; Aksel, Bulent; Yukruk, Fisun Ardic; Kandemir, Olcay

2017-01-16

Liposarcoma is the most frequent type of retroperitoneal sarcomas. Dedifferentiated liposarcoma is the least common subtype and is an extremely rare tumor. We present the case of a 53-year-old male who was referred with a giant retroperitoneal mass. The patients' mass was deemed unresectable by the previous institution and received chemotherapy with no benefit. We macroscopically removed the 38x32 cm mass with right nefrectomy. Pathological examination revealed dedifferentiated liposarcoma. Surgery is the gold standart in the treatment of retroperitoneal sarcomas. Giant masses present a challenge for the surgeon with possible major vascular injuries and multiorgan resections. Therefore it is important for these patients to be referred for surgery without delay. Dedifferentiated liposarcoma, Liposarcoma, Retroperitoneal sarcoma.

Giant hydronephrosis mimicking progressive malignancy

PubMed Central

Schrader, Andres Jan; Anderer, Georgia; von Knobloch, Rolf; Heidenreich, Axel; Hofmann, Rainer

2003-01-01

Background Cases of giant hydronephroses are rare and usually contain no more than 1–2 litres of fluid in the collecting system. We report a remarkable case of giant hydronephrosis mimicking a progressive malignant abdominal tumour. Case presentation A 78-year-old cachectic woman presented with an enormous abdominal tumour, which, according to the patient, had slowly increased in diameter. Medical history was unremarkable except for a hysterectomy >30 years before. A CT scan revealed a giant cystic tumour filling almost the entire abdominal cavity. It was analysed by two independent radiologists who suspected a tumour originating from the right kidney and additionally a cystic ovarian neoplasm. Subsequently, a diagnostic and therapeutic laparotomy was performed: the tumour presented as a cystic, 35 × 30 × 25 cm expansive structure adhesive to adjacent organs without definite signs of invasive growth. The right renal hilar vessels could finally be identified at its basis. After extirpation another tumourous structure emerged in the pelvis originating from the genital organs and was also resected. The histopathological examination revealed a >15 kg hydronephrotic right kidney, lacking hardly any residual renal cortex parenchyma. The second specimen was identified as an ovary with regressive changes and a large partially calcified cyst. There was no evidence of malignant growth. Conclusion Although both clinical symptoms and the enormous size of the tumour indicated malignant growth, it turned out to be a giant hydronephrosis. Presumably, a chronic obstruction of the distal ureter had caused this extraordinary hydronephrosis. As demonstrated in our case, an accurate diagnosis of giant hydronephrosis remains challenging due to the atrophy of the renal parenchyma associated with chronic obstruction. Therefore, any abdominal cystic mass even in the absence of other evident pathologies should include the differential diagnosis of a possible hydronephrosis. Diagnostic

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.

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.

Nanochannel structures in W enhance radiation tolerance

DOE PAGES

Qin, Wenjing; Ren, Feng; Doerner, Russell P.; ...

2018-04-23

Developing high performance plasma facing materials (PFMs) is one of the greatest challenges for fusion reactors, because PFMs face unprecedented harsh environments including high flux plasma exposure, fast neutron irradiation and large transmutation gas. Tungsten (W) is considered as one of the most promising PFMs. Rapid accumulation of helium (He) atoms in such environments can lead to the He bubbles nucleation and even the formation of nano- to micro-scale “fuzz” on W surface, which greatly degrade the properties of W itself. The possible ejection of large W particulates into the core plasma can cause plasma instabilities. In this paper, wemore » present a new strategy to address the root causes of bubble nucleation and “fuzz” formation by concurrently releasing He outside of W matrix through the nano-engineered channel structure (nanochannels). Comparing to ordinary bulk W, nanochannel W films with high surface-to-volume ratios are found to not only delay the growth of He bubbles, but also suppress the formation of “fuzz” (less than a half of the “fuzz” thickness formation in bulk W). Finally, molecular dynamic (MD) simulation results elucidate that low vacancy formation energy and high He binding energy in the nanochannel surface effectively help He release and affect He clusters distribution in W during He ion irradiation.« less

Nanochannel structures in W enhance radiation tolerance

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

Qin, Wenjing; Ren, Feng; Doerner, Russell P.

Developing high performance plasma facing materials (PFMs) is one of the greatest challenges for fusion reactors, because PFMs face unprecedented harsh environments including high flux plasma exposure, fast neutron irradiation and large transmutation gas. Tungsten (W) is considered as one of the most promising PFMs. Rapid accumulation of helium (He) atoms in such environments can lead to the He bubbles nucleation and even the formation of nano- to micro-scale “fuzz” on W surface, which greatly degrade the properties of W itself. The possible ejection of large W particulates into the core plasma can cause plasma instabilities. In this paper, wemore » present a new strategy to address the root causes of bubble nucleation and “fuzz” formation by concurrently releasing He outside of W matrix through the nano-engineered channel structure (nanochannels). Comparing to ordinary bulk W, nanochannel W films with high surface-to-volume ratios are found to not only delay the growth of He bubbles, but also suppress the formation of “fuzz” (less than a half of the “fuzz” thickness formation in bulk W). Finally, molecular dynamic (MD) simulation results elucidate that low vacancy formation energy and high He binding energy in the nanochannel surface effectively help He release and affect He clusters distribution in W during He ion irradiation.« less

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.

Surgical management of giant posterior communicating artery aneurysms.

PubMed

Velat, Gregory J; Zabramski, Joseph M; Nakaji, Peter; Spetzler, Robert F

2012-09-01

Giant posterior communicating artery (PCoA) aneurysms (> 25 mm) are rare lesions associated with a poor prognosis and high rates of morbidity and mortality. To review the clinical results of giant PCoA aneurysms surgically treated at our institution, focusing on operative nuances. All cases of giant PCoA aneurysms treated surgically at our institution were identified from a prospectively maintained patient database. Patient demographic factors, medical comorbidities, rupture status, neurological presentation, clinical outcomes, and surgical records were critically reviewed. From 1989 to 2010, 11 patients (10 women) underwent surgical clipping of giant PCoA aneurysms. Presenting signs and symptoms included cranial nerve palsies, diminished mental status, headache, visual changes, and seizures. Five aneurysms were ruptured on admission. All aneurysms were clipped primarily except 1, which was treated by parent artery sacrifice and extracranial-to-intracranial bypass after intraoperative aneurysm rupture. Perioperative morbidity and mortality rates were 36% (4 of 11) and 18.3% (2 of 11), respectively. Excellent or good clinical outcomes, defined as modified Rankin Scale scores ≤ 2, were achieved in 86% (5 of 6) of patients available for long-term clinical follow-up (mean, 12.5 ± 13.6 months). Giant PCoA aneurysms are rare vascular lesions that may present with a variety of neurological signs and symptoms. These lesions can be successfully managed surgically with satisfactory morbidity and mortality rates. To the best of our knowledge, this is the largest surgical series of giant PCoA aneurysms published to date.

Giant Viruses of Amoebas: An Update

PubMed Central

Aherfi, Sarah; Colson, Philippe; La Scola, Bernard; Raoult, Didier

2016-01-01

During the 12 past years, five new or putative virus families encompassing several members, namely Mimiviridae, Marseilleviridae, pandoraviruses, faustoviruses, and virophages were described. In addition, Pithovirus sibericum and Mollivirus sibericum represent type strains of putative new giant virus families. All these viruses were isolated using amoebal coculture methods. These giant viruses were linked by phylogenomic analyses to other large DNA viruses. They were then proposed to be classified in a new viral order, the Megavirales, on the basis of their common origin, as shown by a set of ancestral genes encoding key viral functions, a common virion architecture, and shared major biological features including replication inside cytoplasmic factories. Megavirales is increasingly demonstrated to stand in the tree of life aside Bacteria, Archaea, and Eukarya, and the megavirus ancestor is suspected to be as ancient as cellular ancestors. In addition, giant amoebal viruses are visible under a light microscope and display many phenotypic and genomic features not found in other viruses, while they share other characteristics with parasitic microbes. Moreover, these organisms appear to be common inhabitants of our biosphere, and mimiviruses and marseilleviruses were isolated from human samples and associated to diseases. In the present review, we describe the main features and recent findings on these giant amoebal viruses and virophages. PMID:27047465

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.

Vocal repertoire of the social giant otter.

PubMed

Leuchtenberger, Caroline; Sousa-Lima, Renata; Duplaix, Nicole; Magnusson, William E; Mourão, Guilherme

2014-11-01

According to the "social intelligence hypothesis," species with complex social interactions have more sophisticated communication systems. Giant otters (Pteronura brasiliensis) live in groups with complex social interactions. It is likely that the vocal communication of giant otters is more sophisticated than previous studies suggest. The objectives of the current study were to describe the airborne vocal repertoire of giant otters in the Pantanal area of Brazil, to analyze call types within different behavioral contexts, and to correlate vocal complexity with level of sociability of mustelids to verify whether or not the result supports the social intelligence hypothesis. The behavior of nine giant otters groups was observed. Vocalizations recorded were acoustically and statistically analyzed to describe the species' repertoire. The repertoire was comprised by 15 sound types emitted in different behavioral contexts. The main behavioral contexts of each sound type were significantly associated with the acoustic variable ordination of different sound types. A strong correlation between vocal complexity and sociability was found for different species, suggesting that the communication systems observed in the family mustelidae support the social intelligence hypothesis.

[Giant papillary conjunctivitis].

PubMed

Bischoff, G

2014-05-01

Giant papillary conjunctivitis is an inflammation of the conjunctiva, which is associated with immunological-allergic disorders, but is difficult to integrate as a defined type of illness. The deposits of contact lenses are responsible in predisposed wearers. They induce a special immune answer to their biochemical ingredients. In addition, roughness of the superficial corneal layers and the conjunctiva, even without any contact lenses after filtrating glaucoma surgery, leads to mechanically induced papillary formations. In former days these symptoms of building giant papillae were seen mostly in wearers of soft hydrogel contact lenses. Nowadays manufacturers have developed contact lens systems with a variety of material components, with an increase of protein and lipid deposits. In combination with the observed non-compliance of wearers regarding lens exchange and contact lens hygiene, GPC is an issue which should be taken into consideration again. Georg Thieme Verlag KG Stuttgart · New York.

Observed Properties of Giant Cells

NASA Technical Reports Server (NTRS)

Hathaway, David H.; Upton, Lisa; Colegrove, Owen

2014-01-01

The existence of Giant Cells has been suggested by both theory and observation for over 45 years. We have tracked the motions of supergranules in SDO/HMI Doppler velocity data and find larger (Giant Cell) flows that persist for months. The flows in these cells are clockwise around centers of divergence in the north and counter-clockwise in the south. Equatorward flows are correlated with prograde flows - giving the transport of angular momentum toward the equator that is needed to maintain the Sun's rapid equatorial rotation. The cells are most pronounced at mid- and high-latitudes where they exhibit the rotation rates representative of those latitudes. These are clearly large, long-lived, cellular features, with the dynamical characteristics expected from the effects of the Sun's rotation, but the shapes of the cells are not well represented in numerical models. While the Giant Cell flow velocities are small (<10 m/s), their long lifetimes should nonetheless substantially impact the transport of magnetic flux in the Sun's near surface layers.

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

Lineage-specific evolution of bitter taste receptor genes in the giant and red pandas implies dietary adaptation.

PubMed

Shan, Lei; Wu, Qi; Wang, Le; Zhang, Lei; Wei, Fuwen

2018-03-01

Taste 2 receptors (TAS2R) mediate bitterness perception in mammals, thus are called bitter taste receptors. It is believed that these genes evolved in response to species-specific diets. The giant panda (Ailuropoda melanoleuca) and red panda (Ailurus fulgens styani) in the order Carnivora are specialized herbivores with an almost exclusive bamboo diet (>90% bamboo). Because bamboo is full of bitter tasting compounds, we hypothesized that adaptive evolution has occurred at TAS2R genes in giant and red pandas throughout the course of their dietary shift. Here, we characterized 195 TAS2R genes in 9 Carnivora species and examined selective pressures on these genes. We found that both pandas harbor more putative functional TAS2R genes than other carnivores, and pseudogenized TAS2R genes in the giant panda are different from the red panda. The purifying selection on TAS2R1, TAS2R9 and TAS2R38 in the giant panda, and TAS2R62 in the red panda, has been strengthened throughout the course of adaptation to bamboo diet, while selective constraint on TAS2R4 and TAS2R38 in the red panda is relaxed. Remarkably, a few positively selected sites on TAS2R42 have been specifically detected in the giant panda. These results suggest an adaptive response in both pandas to a dietary shift from carnivory to herbivory, and TAS2R genes evolved independently in the 2 pandas. Our findings provide new insight into the molecular basis of mammalian sensory evolution and the process of adaptation to new ecological niches. © 2017 The Authors. Integrative Zoology published by International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

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.

Spectroscopy and Photometry of Multiple Populations along the Asymptotic Giant Branch of NGC 2808 and NGC 6121 (M4)

NASA Astrophysics Data System (ADS)

Marino, A. F.; Milone, A. P.; Yong, D.; Da Costa, G.; Asplund, M.; Bedin, L. R.; Jerjen, H.; Nardiello, D.; Piotto, G.; Renzini, A.; Shetrone, M.

2017-07-01

We present a photometric and spectroscopic study of multiple populations along the asymptotic giant branch (AGB) of the intermediate-metallicity globular clusters (GCs) NGC 2808 and NGC 6121 (M4). Chemical abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Co, Ni, Zn, Y, and Ce in AGB stars from high-resolution FLAMES+UVES@VLT spectra are reported for both clusters. Our spectroscopic results have been combined with multiwavelength photometry from the Hubble Space Telescope UV survey of Galactic GCs and ground-based photometry, as well as proper motions derived by combining stellar positions from ground-based images and Gaia DR1. Our analysis reveals that the AGBs of both clusters host multiple populations with different chemical compositions. In M4, we have identified two main populations of stars with different Na/O content lying on distinct AGBs in the {m}{{F}438{{W}}} versus {C}{{F}275{{W}},{{F}}336{{W}},{{F}}438{{W}}} and the V versus {C}{{U},{{B}},{{I}}} pseudo-color-magnitude diagrams. In the more massive and complex GC NGC 2808, three groups of stars with different chemical abundances occupy different locations on the so-called “chromosome map” photometric diagram constructed for AGB stars. The spectroscopic + photometric comparison of stellar populations along the AGB and the red giants of this GC suggests that the AGB hosts stellar populations with a range in helium abundances from primordial to high contents of Y˜ 0.32. By contrast, from our data set, there is no evidence for stars with extreme helium abundance (Y˜ 0.38) on the AGB, suggesting that the most He-rich stars of NGC 2808 do not reach this phase. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programs 093.D-0789 and 094.D-0455 and on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

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.

Giant prolactinomas: are they really different from ordinary macroprolactinomas?

PubMed

Espinosa, Etual; Sosa, Ernesto; Mendoza, Victoria; Ramírez, Claudia; Melgar, Virgilio; Mercado, Moisés

2016-06-01

Giant prolactinomas (gPRLomas) are rare tumors of the lactotroph defined by an unusually large size (>4 cm) and serum PRL levels >1000 ng/mL. The purpose of this study is to characterize the clinical spectrum of gPRLomas comparing them with non-giant prolactinomas. This is a retrospective study at a large referral center. Data from patients harboring gPRLomas and macroprolactinomas were retrieved from medical records of the Prolactinoma Clinic. Analysis was focused on clinical, biochemical, and tumor volume characteristics, as well as on the response to treatment with dopamine agonists. Among 292 patients with prolactinomas followed between 2008 and 2015, 47 (16 %) met the diagnostic criteria for gPRLomas (42 males). The most common complaint was a visual field defect; headache was reported by 79 % and sexual dysfunction was present in over half of the patients. Median basal PRL level and tumor volume were 6667 ng/mL (3750-10,000) and 32 cm(3) (20-50), respectively; hypogonadotropic hypogonadism was documented in 87 %. Cabergoline treatment resulted in the normalization of PRL levels in 68 % and in the reduction of >50 % in tumor volume in 87 % of the gPRLoma patients. The composite goal of PRL normalization and >50 % tumor reduction was achieved by 55 % (n = 26) of patients with gPRL and by 66 % (n = 100) of patients with no giant macroprolactinomas (p = 0.19). Recovery of hypogonadism and improvement of visual fields defects occurred in 32 % and 68 % of the patients, respectively. Cabergoline treatment was equally effective in patients with gPRLoma and those with macroprolactinomas in regard of achieving treatment goals, although the median CBG dose was slightly higher in the gPRLoma group (2 vs. 1.5 mg/w). Six patients required surgery. Beyond their impressive dimensions and the huge amount of PRL they secrete, the clinical behavior of gPRLoma is not different from macroprolactinomas. These tumors are highly responsive to cabergoline

Effect of molecular exchange on water droplet size analysis as determined by diffusion NMR: The W/O/W double emulsion case.

PubMed

Vermeir, Lien; Sabatino, Paolo; Balcaen, Mathieu; Declerck, Arnout; Dewettinck, Koen; Martins, José C; Guthausen, Gisela; Van der Meeren, Paul

2016-08-01

The accuracy of the inner water droplet size determination of W/O/W emulsions upon water diffusion measurement by diffusion NMR was evaluated. The resulting droplet size data were compared to the results acquired from the diffusion measurement of a highly water soluble marker compound with low permeability in the oil layer of a W/O/W emulsion, which provide a closer representation of the actual droplet size. Differences in droplet size data obtained from water and the marker were ascribed to extra-droplet water diffusion. The diffusion data of the tetramethylammonium cation marker were measured using high-resolution pulsed field gradient NMR, whereas the water diffusion was measured using both low-resolution and high-resolution NMR. Different data analysis procedures were evaluated to correct for the effect of extra-droplet water diffusion on the accuracy of water droplet size analysis. Using the water diffusion data, the use of a low measurement temperature and diffusion delay Δ could reduce the droplet size overestimation resulting from extra-droplet water diffusion, but this undesirable effect was inevitable. Detailed analysis of the diffusion data revealed that the extra-droplet diffusion effect was due to an exchange between the inner water phase and the oil phase, rather than by exchange between the internal and external aqueous phase. A promising data analysis procedure for retrieving reliable size data consisted of the application of Einstein's diffusion law to the experimentally determined diffusion distances. This simple procedure allowed determining the inner water droplet size of W/O/W emulsions upon measurement of water diffusion by low-resolution NMR at or even above room temperature. Copyright © 2016 Elsevier Inc. All rights reserved.

Management of giant paraesophageal hernia.

PubMed

Awais, O; Luketich, J D

2009-04-01

Management of giant paraesophageal hernia remains one of the most difficult challenges faced by surgeons treating complex benign esophageal disorders. These large hernias are acquired disorders; therefore, they invariably present in elderly patients. The dilemma that surgeons faced in the open surgical era was the risk of open surgery in this elderly, sick patient population versus the life threatening catastrophic complications, nearly 30% in some series, observed with medical management. During the 1990s, it was clearly recognized that laparoscopic surgery led to decreased morbidity with a quicker recovery. This has lead to a 6-fold increase in the surgical management of giant paraesophageal hernias over the last decade compared to a period of five decades of open surgery; however, this has not necessarily translated into better outcomes. One of the major issues with giant paraesophageal hernias is recognizing short esophagus and performing a lengthening procedure, if needed. Open series which report liberal use of Collis gastroplasty leading to a tension-free intraabdominal fundoplication have shown the best anatomic and clinical outcomes. As we duplicate the open experience laparoscopically, the principle of identifying a shortened esophagus and constructing a neo-esophagus must be honored for the success of the operation. The benefits of laparoscopy are obvious but should not come at the cost of a lesser operation. This review will illustrate that laparoscopic repair of giant paraesophageal hernia at experienced centers can be performed safely with similar outcomes to open series when the fundamental principles of the operation are maintained.

W-band PELDOR with 1 kW microwave power: molecular geometry, flexibility and exchange coupling.

PubMed

Reginsson, Gunnar W; Hunter, Robert I; Cruickshank, Paul A S; Bolton, David R; Sigurdsson, Snorri Th; Smith, Graham M; Schiemann, Olav

2012-03-01

A technique that is increasingly being used to determine the structure and conformational flexibility of biomacromolecules is Pulsed Electron-Electron Double Resonance (PELDOR or DEER), an Electron Paramagnetic Resonance (EPR) based technique. At X-band frequencies (9.5 GHz), PELDOR is capable of precisely measuring distances in the range of 1.5-8 nm between paramagnetic centres but the orientation selectivity is weak. In contrast, working at higher frequencies increases the orientation selection but usually at the expense of decreased microwave power and PELDOR modulation depth. Here it is shown that a home-built high-power pulsed W-band EPR spectrometer (HiPER) with a large instantaneous bandwidth enables one to achieve PELDOR data with a high degree of orientation selectivity and large modulation depths. We demonstrate a measurement methodology that gives a set of PELDOR time traces that yield highly constrained data sets. Simulating the resulting time traces provides a deeper insight into the conformational flexibility and exchange coupling of three bisnitroxide model systems. These measurements provide strong evidence that W-band PELDOR may prove to be an accurate and quantitative tool in assessing the relative orientations of nitroxide spin labels and to correlate those orientations to the underlying biological structure and dynamics. Copyright © 2012 Elsevier Inc. All rights reserved.

Giant virus Megavirus chilensis encodes the biosynthetic pathway for uncommon acetamido sugars.

PubMed

Piacente, Francesco; De Castro, Cristina; Jeudy, Sandra; Molinaro, Antonio; Salis, Annalisa; Damonte, Gianluca; Bernardi, Cinzia; Abergel, Chantal; Tonetti, Michela G

2014-08-29

Giant viruses mimicking microbes, by the sizes of their particles and the heavily glycosylated fibrils surrounding their capsids, infect Acanthamoeba sp., which are ubiquitous unicellular eukaryotes. The glycans on fibrils are produced by virally encoded enzymes, organized in gene clusters. Like Mimivirus, Megavirus glycans are mainly composed of virally synthesized N-acetylglucosamine (GlcNAc). They also contain N-acetylrhamnosamine (RhaNAc), a rare sugar; the enzymes involved in its synthesis are encoded by a gene cluster specific to Megavirus close relatives. We combined activity assays on two enzymes of the pathway with mass spectrometry and NMR studies to characterize their specificities. Mg534 is a 4,6-dehydratase 5-epimerase; its three-dimensional structure suggests that it belongs to a third subfamily of inverting dehydratases. Mg535, next in the pathway, is a bifunctional 3-epimerase 4-reductase. The sequential activity of the two enzymes leads to the formation of UDP-l-RhaNAc. This study is another example of giant viruses performing their glycan synthesis using enzymes different from their cellular counterparts, raising again the question of the origin of these pathways. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

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

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.

[Clinicopathologic characteristics of hemangiopericytoma/solitary fibrous tumor with giant cells].

PubMed

Wang, Hai-yan; Fan, Qin-he; Gong, Qi-xing; Wang, Zheng

2009-03-01

To study the pathological characteristics, diagnosis and differential diagnoses of hemangiopericytoma-solitary fibrous tumor with giant cells. Pathological characteristics of seven cases of orbital and extraorbital hemangiopericytoma-solitary fibrous tumors with giant cells were evaluated by HE and immunohistochemistry (EnVision method). Two cases were located in the orbit, one of which had recurred. Five cases were located in the extraorbital regions. Histologically, the tumors were well-circumscribed and composed of non-atypical, round to spindle cells with collagen deposition in the stroma. The tumors had prominent vasculatures and in areas, pseudovascular spaces lined by multinucleated giant cells lining which were also present in the stroma. Immunohistochemically, both neoplastic cells and multinucleate giant cells expressed CD34. Seven patients underwent tumor excision and were well and without tumor recurrence upon the clinical follow-up. Hemangiopericytoma-solitary fibrous tumor with giant cells is an intermediate soft tissue tumor. It typically involves the orbital or extraorbital regions. Histologically, the tumor should be distinguished from giant cell fibroblastoma, pleomorphic hyalinzing angiectatic tumor of soft part and angiomatoid fibrous histiocytoma.

AXOPLASMIC PROTEINS OF THE SQUID GIANT NERVE FIBER WITH PARTICULAR REFERENCE TO THE FIBROUS PROTEIN

PubMed Central

Maxfield, Myles

1953-01-01

1. Axoplasm of squid giant nerve fibers is examined with the ultracentrifuge and electrophoresis apparatus and several distinct components demonstrated. 2. One of these components, a protein called axon filaments, is isolated by fractional extraction followed by differential ultracentrifugation and redissolving in glycine solution. Axon filaments are monodisperse by ultracentrifugation. Their physical chemical properties have been studied. 3. The existence of a reversible transformation of axon filaments into a particle of lower molecular weight and lower asymmetry has been demonstrated. PMID:13109156

RESOLVED GIANT MOLECULAR CLOUDS IN NEARBY SPIRAL GALAXIES: INSIGHTS FROM THE CANON CO (1-0) SURVEY

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

Donovan Meyer, Jennifer; Koda, Jin; Mooney, Thomas

We resolve 182 individual giant molecular clouds (GMCs) larger than 2.5 Multiplication-Sign 10{sup 5} M{sub Sun} in the inner disks of 5 large nearby spiral galaxies (NGC 2403, NGC 3031, NGC 4736, NGC 4826, and NGC 6946) to create the largest such sample of extragalactic GMCs within galaxies analogous to the Milky Way. Using a conservatively chosen sample of GMCs most likely to adhere to the virial assumption, we measure cloud sizes, velocity dispersions, and {sup 12}CO (J = 1-0) luminosities and calculate cloud virial masses. The average conversion factor from CO flux to H{sub 2} mass (or X{sub CO})more » for each galaxy is 1-2 Multiplication-Sign 10{sup 20} cm{sup -2} (K km s{sup -1}){sup -1}, all within a factor of two of the Milky Way disk value ({approx}2 Multiplication-Sign 10{sup 20} cm{sup -2} (K km s{sup -1}){sup -1}). We find GMCs to be generally consistent within our errors between the galaxies and with Milky Way disk GMCs; the intrinsic scatter between clouds is of order a factor of two. Consistent with previous studies in the Local Group, we find a linear relationship between cloud virial mass and CO luminosity, supporting the assumption that the clouds in this GMC sample are gravitationally bound. We do not detect a significant population of GMCs with elevated velocity dispersions for their sizes, as has been detected in the Galactic center. Though the range of metallicities probed in this study is narrow, the average conversion factors of these galaxies will serve to anchor the high metallicity end of metallicity-X{sub CO} trends measured using conversion factors in resolved clouds; this has been previously possible primarily with Milky Way measurements.« less

Migration of accreting giant planets

NASA Astrophysics Data System (ADS)

Robert, C.; Crida, A.; Lega, E.; Méheut, H.

2017-09-01

Giant planets forming in protoplanetary disks migrate relative to their host star. By repelling the gas in their vicinity, they form gaps in the disk's structure. If they are effectively locked in their gap, it follows that their migration rate is governed by the accretion of the disk itself onto the star, in a so-called type II fashion. Recent results showed however that a locking mechanism was still lacking, and was required to understand how giant planets may survive their disk. We propose that planetary accretion may play this part, and help reach this slow migration regime.

Purification and in vitro antioxidative effects of giant squid muscle peptides on free radical-mediated oxidative systems.

PubMed

Rajapakse, Niranjan; Mendis, Eresha; Byun, Hee-Guk; Kim, Se-Kwon

2005-09-01

Low molecular weight peptides obtained from ultrafiltration (UF) of giant squid (Dosidicus gigas) muscle protein were studied for their antioxidative effects in different in vitro oxidative systems. The most potent two peptides, Asn-Ala-Asp-Phe-Gly-Leu-Asn-Gly-Leu-Glu-Gly-Leu-Ala (1307 Da) and Asn-Gly-Leu-Glu-Gly-Leu-Lys (747 Da), exhibited their antioxidant potential to act as chain-breaking antioxidants by inhibiting radical-mediated peroxidation of linoleic acid, and their activities were closer to highly active synthetic antioxidant, butylated hydroxytoluene. Addition of these peptides could enhance the viability of cytotoxic embryonic lung fibroblasts significantly (P<.05) at a low concentration of 50 microg/ml, and it was presumed due to the suppression of radical-induced oxidation of membrane lipids. Electron spin trapping studies revealed that the peptides were potent scavengers of free radicals in the order of carbon-centered (IC(50) 396.04 and 304.67 microM), hydroxyl (IC(50) 497.32 and 428.54 microM) and superoxide radicals (IC(50) 669.34 and 573.83 microM). Even though the exact molecular mechanism for scavenging of free radicals was unclear, unusually high hydrophobic amino acid composition (more than 75%) of giant squid muscle peptides was presumed to be involved in the observed activities.

Overexpression, purification, molecular characterization and the effect on tumor growth of ribosomal protein L22 from the Giant Panda (Ailuropoda melanoleuca).

PubMed

Li, Jian; Hou, Yiling; Ding, Xiang; Hou, Wanru; Song, Bo; Zeng, Yichun

2014-05-01

The ribosomal protein L22 (RPL22) protein belongs to the L22E family of ribosomal proteins. It is located in the cytoplasm. The purpose of this paper was to explore the structure and anti-cancer function of RPL22 of the Giant Panda (Ailuropoda melanoleuca). The cDNA of RPL22 was cloned successfully from the Giant Panda using RT-PCR technology. We constructed a recombinant expression vector containing RPL22 cDNA and over-expressed it in Escherichia coli using pET28a plasmids. The expression product obtained was purified by using Ni chelating affinity chromatography. The result indicated that the length of the fragment cloned is 414 bp, and it contains an open-reading frame of 387 bp encoding 128 amino acids. Primary structure analysis revealed that the molecular weight of the putative RPL22 protein is 14.74 kDa with a theoretical pI 9.21. The RPL22 gene can be really expressed in E. coli and the RPL22 protein, fusioned with the N-terminally His-tagged protein, gave rise to the accumulation of an expected 20.1 kDa polypeptide. The data showed that the recombinant protein RPL22 had a time- and dose-dependency on the cell growth inhibition rate. The human laryngeal carcinoma Hep-2 cells treated with 0.05-6 μg/ml of RPL22 for 24 h displayed significant cell growth inhibition (p<0.05, n=8) in assayed using MTT compared to the control (untreated) cells. The data indicate that the effect at low concentrations is better than high concentrations, and the concentration of 1.5 μg/ml has the best rate of growth inhibition of 47.70%. The inhibitory rate in mice treated with 1.5 μg/ml RPL22 protein can reach 43.75%. Histology of tumor organs shows that the tissues arranged looser in RPL22 group than those in control group. Meanwhile, there is no obvious damage to other organs, such as heart, lung and kidney. Further research is on going to determine the bioactive principle(s) of recombinant protein RPL22 responsible for its anticancer activity.

STS-51 astronauts photographed during sleep period on Discovery's middeck

NASA Technical Reports Server (NTRS)

1993-01-01

Four of the five STS-51 crew members were photographed during one of their sleep periods on Discovery's middeck. At bottom center, astronaut Frank L. Culbertson Jr., mission commander, is barely visible, with most of his body zipped securely in the sleep restraint. Others, left to right, are astronauts Daniel W. Bursch and Carl E. Walz, mission specialists, and William F. Readdy, pilot. The photograph was taken by astronaut James H. Newman, mission specialist.

STS-51 astronauts participate in emergency bailout training in WETF

NASA Image and Video Library

1993-03-24

S93-31929 (24 March 1993) --- The three mission specialists for NASA's STS-51 mission watch as a crewmate (out of frame) simulates a parachute jump into water during emergency bailout training exercises at the Johnson Space Center's Weightless Environment Training Facility (WET-F). Left to right are astronauts Daniel W. Bursch, Carl E. Walz and James H. Newman. Out of frame are astronauts Frank L. Culbertson and William F. Readdy, commander and pilot, respectively.

Structural Basis of Human CYP51 Inhibition by Antifungal Azoles

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

Strushkevich, Natallia; Usanov, Sergey A.; Park, Hee-Won

2010-09-22

The obligatory step in sterol biosynthesis in eukaryotes is demethylation of sterol precursors at the C14-position, which is catalyzed by CYP51 (sterol 14-alpha demethylase) in three sequential reactions. In mammals, the final product of the pathway is cholesterol, while important intermediates, meiosis-activating sterols, are produced by CYP51. Three crystal structures of human CYP51, ligand-free and complexed with antifungal drugs ketoconazole and econazole, were determined, allowing analysis of the molecular basis for functional conservation within the CYP51 family. Azole binding occurs mostly through hydrophobic interactions with conservative residues of the active site. The substantial conformational changes in the B{prime} helix andmore » F-G loop regions are induced upon ligand binding, consistent with the membrane nature of the protein and its substrate. The access channel is typical for mammalian sterol-metabolizing P450 enzymes, but is different from that observed in Mycobacterium tuberculosis CYP51. Comparison of the azole-bound structures provides insight into the relative binding affinities of human and bacterial P450 enzymes to ketoconazole and fluconazole, which can be useful for the rational design of antifungal compounds and specific modulators of human CYP51.« less

Modeling Hf-W Evolution for Earth, Moon and Mars in Grand Tack Accretion Simulations: The Isotopic Consequences of Rapid Accretion

NASA Astrophysics Data System (ADS)

Zube, N.; Nimmo, F.; Jacobson, S. A.; Fischer, R. A.

2017-12-01

Short-lived isotopes, such as the decay of lithophile 182Hf into siderophile 182W with a half-life of 9 My, can provide constraints on the timescales of planetary core formation and accretion. Classical accretion scenarios have produced Hf-W isotopic outcomes like those measured presently on the Earth [2,3]. We examine Grand Tack accretion simulations [4,5] and determine the mantle equilibration conditions necessary to produce the observed tungsten isotopic anomaly. Additionally, we follow Hf-W evolution for pairs of bodies that experience a last giant impact fitting the conditions of Earth's Moon-forming collision. In this way, we determine the likelihood of producing the observed almost indistinguishable W isotope anomalies of the Earth and Moon mantles [6]. We model Hf-W evolution for growing planets in 141 N-body simulations during late accretion in the Grand Tack scenario. For each case, we vary the equilibration factor during collisions—the fraction of impactor core that experiences re-equilibration with the entire target mantle—in steps ranging from none (cores merging) to complete equilibration. For Earth-like and Mars-like surviving planets, we find that cases with a high equilibration factor (k > 0.8) and an intermediate (2:1 - 4:1) ratio of initial embryo mass to planetesimal mass were most frequently able to approximate the observed W measurements for Earth and Mars. The equilibration factor required is more restrictive than the one found for classical accretion scenarios [2,3] and may not be consistent with fluid-dynamical predictions [7]. Moons made of impactor material from Earth's last giant impact are only able to result in an Earth-Moon pair having sufficiently similar W anomalies with a likelihood of 8% or less across all simulations. This indicates that a scenario where the Moon isotopically equilibrated with the Earth's mantle after the impact [8] may be required to explain the measured values. [1] Kleine et al. 2009 [2] Nimmo et al. 2010

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.

Masses and Ages for 230,000 LAMOST Giants, via Their Carbon and Nitrogen Abundances

NASA Astrophysics Data System (ADS)

Ho, Anna Y. Q.; Rix, Hans-Walter; Ness, Melissa K.; Hogg, David W.; Liu, Chao; Ting, Yuan-Sen

2017-05-01

We measure carbon and nitrogen abundances to a precision of ≲ 0.1 dex for 450,000 giant stars from their low-resolution (R∼ 1800) LAMOST DR2 survey spectra. We use these [{{C}}/{{M}}] and [{{N}}/{{M}}] measurements, together with empirical relations based on the APOKASC sample, to infer stellar masses and implied ages for 230,000 of these objects to 0.08 dex and 0.2 dex respectively. We use The Cannon, a data-driven approach to spectral modeling, to construct a predictive model for LAMOST spectra. Our reference set comprises 8125 stars observed in common between the APOGEE and LAMOST surveys, taking seven APOGEE DR12 labels (parameters) as ground truth: {T}eff}, {log} g, [{{M}}/{{H}}], [α /{{M}}], [{{C}}/{{M}}], [{{N}}/{{M}}], and {A}{{k}}. We add seven colors to the Cannon model, based on the g, r, i, J, H, K, W1, W2 magnitudes from APASS, 2MASS, and WISE, which improves our constraints on {T}eff} and {log} g by up to 20% and on {A}{{k}} by up to 70%. Cross-validation of the model demonstrates that, for high-{{S}}/{{N}} objects, our inferred labels agree with the APOGEE values to within 50 K in temperature, 0.04 mag in {A}{{k}}, and < 0.1 dex in {log} g, [{{M}}/{{H}}], [{{C}}/{{M}}], [{{N}}/{{M}}], and [α /{{M}}]. We apply the model to 450,000 giants in LAMOST DR2 that have not been observed by APOGEE. This demonstrates that precise individual abundances can be measured from low-resolution spectra and represents the largest catalog to date of homogeneous stellar [{{C}}/{{M}}], [{{N}}/{{M}}], masses, and ages. As a result, we greatly increase the number and sky coverage of stars with mass and age estimates.

[Intestinal fungal diversity of sub-adult giant panda].

PubMed

Ai, Shengquan; Zhong, Zhijun; Peng, Guangneng; Wang, Chengdong; Luo, Yongjiu; He, Tingmei; Gu, Wuyang; Li, Caiwu; Li, Gangshi; Wu, Honglin; Liu, Xuehan; Xia, Yu; Liu, Yanhong; Zhou, Xiaoxiao

2014-11-04

The fungi diversity in the guts of five sub-adult giant pandas was analyzed. We analyzed the fungal internal transcribed spacer sequences (ITS) using restriction fragment length polymorphism (RFLP). ITS regions were amplified with fungal universal primers to construct ITS clone libraries. The fingerprints were analyzed by restriction fragment length polymorphism using the Hha I and Hae III enzymes. The cloned PCR products were analyzed by sequencing and diversities were demonstrated by phylogenetic tree. The gut fungi of 5 sub-adult giant pandas were mainly composed of Ascomycota (average of 46.24%), Basidiomycota ( average of 15.79%), unclassified (average of 29.14%), uncultured fungus (average of 8.83% ). Ascomycota was mainly composed of Saccharomycetes (average of 63.74%) and Dothideomycetes ( average of 35.91%); Basidiomycota was mainly composed of Tremellomycetes (average of 65.80%) and Microbotryomycetes (average of 33.15%). Four classes were mainly composed of Candida and Debaryomyces; Pleosporales and Myriangium; Cystofilobasidium and Trichosporon; Leucosporidium, and Leucosporidiella, whereas the proportions were different for each sample. Fungal flora existing in the intestines of sub-adult giant pandas expand our knowledge on the structure of the giant panda gut microbes and also help us to further study whether fungal flora can help giant pandas digest high-fiber foods.

Silvics of Giant Sequoia

Treesearch

C. Phillip Weatherspoon

1986-01-01

Ecological relationships-including habitat and life history---of giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz) in natural stands are summarized. Such silvical information provides an important foundation for sound management of the species.

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.

Provirophages and transpovirons as the diverse mobilome of giant viruses.

PubMed

Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Saïd; Jardot, Priscilla; Monteil, Sonia; Campocasso, Angélique; Koonin, Eugene V; Raoult, Didier

2012-10-30

A distinct class of infectious agents, the virophages that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements, the transpovirons. The transpovirons are linear DNA elements of ~7 kb that encompass six to eight protein-coding genes, two of which are homologous to virophage genes. Fluorescence in situ hybridization showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer.

Provirophages and transpovirons as the diverse mobilome of giant viruses

PubMed Central

Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Saïd; Jardot, Priscilla; Monteil, Sonia; Campocasso, Angélique; Koonin, Eugene V.; Raoult, Didier

2012-01-01

A distinct class of infectious agents, the virophages that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements, the transpovirons. The transpovirons are linear DNA elements of ∼7 kb that encompass six to eight protein-coding genes, two of which are homologous to virophage genes. Fluorescence in situ hybridization showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer. PMID:23071316

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

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

Infection and Proliferation of Giant Viruses in Amoeba Cells.

PubMed

Takemura, Masaharu

2016-01-01

Acanthamoeba polyphaga mimivirus, the first discovered giant virus with genome size and particle size much larger than previously discovered viruses, possesses several genes for translation and CRISPER Cas system-like defense mechanism against virophages, which co-infect amoeba cells with the giant virus and which inhibit giant virus proliferation. Mimiviruses infect amoeba cells by phagocytosis and release their DNA into amoeba cytoplasm through their stargate structure. After infection, giant virion factories (VFs) form in amoeba cytoplasm, followed by DNA replication and particle formation at peripheral regions of VF. Marseilleviruses, the smallest giant viruses, infect amoeba cells by phagocytosis or endocytosis, form larger VF than Mimivirus's VF in amoeba cytoplasm, and replicate their particles. Pandoraviruses found in 2013 have the largest genome size and particle size among all viruses ever found. Pandoraviruses infect amoeba cells by phagocytosis and release their DNA into amoeba cytoplasm through their mouth-like apical pores. The proliferation of Pandoraviruses occurs along with nucleus disruption. New virions form at the periphery of the region formerly occupied by the amoeba cell nucleus.

Laughing headache with giant pacchionian granulations.

PubMed

Giraud, Pierric; Segal, Olivier; Chauvet, Sylvie

2013-04-01

Laughing is recognized as a provoking factor for headache, certainly underestimated among the general population and few cases have been published to date. We report a single case of severe headache, provoked almost exclusively by outbursts of laughing, where venous magnetic resonance imaging revealed the presence of giant Pacchioni granulations in both right and transverse sinuses. Reviewing published cases of laughing headache, we discuss possible mechanisms of pain and the role of giant Pacchionian granulations. © 2013 American Headache Society.

Pulmonary giant cell carcinoma associated with pseudomyxoma peritonei.

PubMed

Goldin, Mark; Li, Jinghong; Amirrezvani, Ali; Riker, David

2012-01-01

Pulmonary giant cell carcinoma is a rare subtype of sarcomatoid carcinoma. Pseudomyxoma peritonei (PMP) is a rare condition in which gelatinous material accumulates within the peritoneal cavity. It is believed PMP arises from a primary appendiceal mucinous neoplasm that perforates the gut, causing mucinous ascites. There are sporadic reports of PMP associated with neoplasms of other organs, rarely the lung. Here, we report on a 60-year-old woman with pulmonary giant cell carcinoma associated with PMP. She presented with progressive dyspnea and abdominal distention. Abdominal computed tomography revealed moderately dense ascites without an obvious mass. Chest computed tomography revealed a large, solitary right lower-lobe lung mass. She underwent transbronchial fine-needle aspiration of the mass, and was diagnosed with pulmonary giant cell carcinoma. The ascites showed scattered malignant cells in a background of mucin, confirming PMP. To our knowledge, this is the first report of pulmonary giant cell carcinoma associated with PMP.

Asteroseismic Diagram for Subgiants and Red Giants