Why Blue stragglers formed via collisions may not be rapid rotators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leonard, P.J.T.; Clement, M.J.
1993-03-01
We propose that the blue stragglers formed via collisions may not be rapid rotators due to magnetic braking during a Hayashi phase as they approach the main sequence. It is conceivable that just the envelopes of the blue stragglers are spun down, while their cores remain rapidly rotating. This would greatly extend the main-sequence lifetimes of the blue stragglers produced by collisions.
Why Blue stragglers formed via collisions may not be rapid rotators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leonard, P.J.T.; Clement, M.J.
1993-01-01
We propose that the blue stragglers formed via collisions may not be rapid rotators due to magnetic braking during a Hayashi phase as they approach the main sequence. It is conceivable that just the envelopes of the blue stragglers are spun down, while their cores remain rapidly rotating. This would greatly extend the main-sequence lifetimes of the blue stragglers produced by collisions.
UV observations of blue stragglers and population 2 K dwarfs
NASA Technical Reports Server (NTRS)
Carney, B. W.; Bond, H. E.
1986-01-01
Blue stragglers are stars, found usually in either open or globular clusters, that appear to lie on the main sequence, but are brighter and bluer than the cluster turn-off. Currently, two rival models are invoked to explain this apparently pathological behavior: internal mixing (so that fresh fuel is brought into the stellar core); and mass transfer (by which a normal main sequence star acquires mass from an evolving nearby companion and so moves up the main sequence). The latter model predicts that in the absence of complete mass transfer (i.e., coalescence), blue stragglers should be binary systems with the fainter star in a post-main sequence evolutionary state. It is important to ascertain the cause of this phenomenon since stellar evolution models of main sequence stars play such a vital role in astronomy. If mass transfer is involved, one may easily exclude binaries from age determinations of clusters, but if mixing is the cause, our age determinations will be much less accurate unless we can determine whether all stars or only some mix, and what causes the mixing to occur at all.
New Insights into the Formation of the Blue Main Sequence in NGC 1850
NASA Astrophysics Data System (ADS)
Yang, Yujiao; Li, Chengyuan; Deng, Licai; de Grijs, Richard; Milone, Antonino P.
2018-06-01
Recent discoveries of bimodal main sequences (MSs) associated with young clusters (with ages ≲1 Gyr) in the Magellanic Clouds have drawn a lot of attention. One of the prevailing formation scenarios attributes these split MSs to a bimodal distribution in stellar rotation rates, with most stars belonging to a rapidly rotating population. In this scenario, only a small fraction of stars populating a secondary blue sequence are slowly or non-rotating stars. Here, we focus on the blue MS in the young cluster NGC 1850. We compare the cumulative number fraction of the observed blue-MS stars to that of the high-mass-ratio binary systems at different radii. The cumulative distributions of both populations exhibit a clear anti-correlation, characterized by a highly significant Pearson coefficient of ‑0.97. Our observations are consistent with the possibility that blue-MS stars are low-mass-ratio binaries, and therefore their dynamical disruption is still ongoing. High-mass-ratio binaries, on the other hand, are more centrally concentrated.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Geller, Aaron M.; Hurley, Jarrod R.; Mathieu, Robert D., E-mail: a-geller@northwestern.edu, E-mail: mathieu@astro.wisc.edu, E-mail: jhurley@astro.swin.edu.au
2013-01-01
Following on from a recently completed radial-velocity survey of the old (7 Gyr) open cluster NGC 188 in which we studied in detail the solar-type hard binaries and blue stragglers of the cluster, here we investigate the dynamical evolution of NGC 188 through a sophisticated N-body model. Importantly, we employ the observed binary properties of the young (180 Myr) open cluster M35, where possible, to guide our choices for parameters of the initial binary population. We apply pre-main-sequence tidal circularization and a substantial increase to the main-sequence tidal circularization rate, both of which are necessary to match the observed tidalmore » circularization periods in the literature, including that of NGC 188. At 7 Gyr the main-sequence solar-type hard-binary population in the model matches that of NGC 188 in both binary frequency and distributions of orbital parameters. This agreement between the model and observations is in a large part due to the similarities between the NGC 188 and M35 solar-type binaries. Indeed, among the 7 Gyr main-sequence binaries in the model, only those with P {approx}> 1000 days begin to show potentially observable evidence for modifications by dynamical encounters, even after 7 Gyr of evolution within the star cluster. This emphasizes the importance of defining accurate initial conditions for star cluster models, which we propose is best accomplished through comparisons with observations of young open clusters like M35. Furthermore, this finding suggests that observations of the present-day binaries in even old open clusters can provide valuable information on their primordial binary populations. However, despite the model's success at matching the observed solar-type main-sequence population, the model underproduces blue stragglers and produces an overabundance of long-period circular main-sequence-white-dwarf binaries as compared with the true cluster. We explore several potential solutions to the paucity of blue stragglers and conclude that the model dramatically underproduces blue stragglers through mass-transfer processes. We suggest that common-envelope evolution may have been incorrectly imposed on the progenitors of the spurious long-period circular main-sequence-white-dwarf binaries, which perhaps instead should have gone through stable mass transfer to create blue stragglers, thereby bringing both the number and binary frequency of the blue straggler population in the model into agreement with the true blue stragglers in NGC 188. Thus, improvements in the physics of mass transfer and common-envelope evolution employed in the model may in fact solve both discrepancies with the observations. This project highlights the unique accessibility of open clusters to both comprehensive observational surveys and full-scale N-body simulations, both of which have only recently matured sufficiently to enable such a project, and underscores the importance of open clusters to the study of star cluster dynamics.« less
SN 1987A - The evolution from red to blue
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tuchman, Y.; Wheeler, J.C.
1989-11-01
Envelope models in thermal and dynamic equilibrium are used to explore the nature of the transition of SK -69 deg 202, the progenitor of SN 1987A, from the Hayashi track to its final blue position in the H-R diagram. Loci of possible thermal equilibrium solutions are presented as a function of Teff and M(C/O), the mass of the carbon/oxygen core interior to the helium burning shell. It is found that uniform helium enrichment of the envelope results in red-blue evolution but that the resulting blue solution is much hotter than SK -69 deg 202. Solutions in which the only changemore » is to redistribute the portion of the envelope enriched in helium during main-sequence convective core contraction into a step function with Y of about 0.5 at a mass cut of about 10 solar masses give a natural transition from red to blue and a final value of Teff in agreement with observations. It is argued that SK -69 deg 202 probably fell on a post-Hayashi track sequence at moderate Teff. The possible connection of this sequence to the step distribution in the H-R diagram of the LMC. 19 refs.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davidge, T. J.
2012-12-20
The stellar contents of the open clusters King 12, NGC 7788, and NGC 7790 are investigated using MegaCam images. Comparisons with isochrones yield an age <20 Myr for King 12, 20-40 Myr for NGC 7788, and 60-80 Myr for NGC 7790 based on the properties of stars near the main-sequence turnoff (MSTO) in each cluster. The reddening of NGC 7788 is much larger than previously estimated. The luminosity functions (LFs) of King 12 and NGC 7788 show breaks that are attributed to the onset of pre-main-sequence (PMS) objects, and comparisons with models of PMS evolution yield ages that are consistentmore » with those measured from stars near the MSTO. In contrast, the r' LF of main-sequence stars in NGC 7790 is matched to r' = 20 by a model that is based on the solar neighborhood mass function. The structural properties of all three clusters are investigated by examining the two-point angular correlation function of blue main-sequence stars. King 12 and NGC 7788 are each surrounded by a stellar halo that extends out to a radius of 5 arcmin ({approx}3.4 pc). It is suggested that these halos form in response to large-scale mass ejection early in the evolution of the clusters, as predicted by models. In contrast, blue main-sequence stars in NGC 7790 are traced out to a radius of {approx}7.5 arcmin ({approx}5.5 pc), with no evidence of a halo. It is suggested that all three clusters may have originated in the same star-forming complex, but not in the same giant molecular cloud.« less
THE GALEX/S{sup 4}G UV–IR COLOR–COLOR DIAGRAM: CATCHING SPIRAL GALAXIES AWAY FROM THE BLUE SEQUENCE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bouquin, Alexandre Y. K.; Gil de Paz, Armando; Gallego, Jesús
We obtained GALEX FUV, NUV, and Spitzer/IRAC 3.6 μm photometry for >2000 galaxies, available for 90% of the S{sup 4}G sample. We find a very tight GALEX blue sequence (GBS) in the (FUV–NUV) versus (NUV–[3.6]) color–color diagram, which is populated by irregular and spiral galaxies, and is mainly driven by changes in the formation timescale (τ) and a degeneracy between τ and dust reddening. The tightness of the GBS provides an unprecedented way of identifying star-forming galaxies and objects that are just evolving to (or from) what we call the GALEX green valley (GGV). At the red end of the GBS, atmore » (NUV–[3.6]) > 5, we find a wider GALEX red sequence (GRS) mostly populated by E/S0 galaxies that has a perpendicular slope to that of the GBS and of the optical red sequence. We find no such dichotomy in terms of stellar mass (measured by M{sub [3.6]}) since both massive (M{sub ⋆}>10{sup 11}M{sub ⊙}) blue- and red-sequence galaxies are identified. The type that is proportionally more often found in the GGV is the S0-Sa’s, and most of these are located in high-density environments. We discuss evolutionary models of galaxies that show a rapid transition from the blue to the red sequence on a timescale of 10{sup 8} yr.« less
The GALEX/S4G UV-IR Color-Color Diagram: Catching Spiral Galaxies Away from the Blue Sequence
NASA Astrophysics Data System (ADS)
Bouquin, Alexandre Y. K.; Gil de Paz, Armando; Boissier, Samuel; Muñoz-Mateos, Juan-Carlos; Sheth, Kartik; Zaritsky, Dennis; Laine, Jarkko; Gallego, Jesús; Peletier, Reynier F.; Röck, Benjamin R.; Knapen, Johan H.
2015-02-01
We obtained GALEX FUV, NUV, and Spitzer/IRAC 3.6 μm photometry for \\gt 2000 galaxies, available for 90% of the S4G sample. We find a very tight GALEX blue sequence (GBS) in the (FUV-NUV) versus (NUV-[3.6]) color-color diagram, which is populated by irregular and spiral galaxies, and is mainly driven by changes in the formation timescale (τ) and a degeneracy between τ and dust reddening. The tightness of the GBS provides an unprecedented way of identifying star-forming galaxies and objects that are just evolving to (or from) what we call the GALEX green valley (GGV). At the red end of the GBS, at (NUV-[3.6]) \\gt 5, we find a wider GALEX red sequence (GRS) mostly populated by E/S0 galaxies that has a perpendicular slope to that of the GBS and of the optical red sequence. We find no such dichotomy in terms of stellar mass (measured by {{M}[3.6]}) since both massive ({{M}\\star }\\gt {{10}11}{{M}⊙ }) blue- and red-sequence galaxies are identified. The type that is proportionally more often found in the GGV is the S0-Sa’s, and most of these are located in high-density environments. We discuss evolutionary models of galaxies that show a rapid transition from the blue to the red sequence on a timescale of 108 yr.
Stars caught in the braking stage in young Magellanic Cloud clusters
NASA Astrophysics Data System (ADS)
D'Antona, Francesca; Milone, Antonino P.; Tailo, Marco; Ventura, Paolo; Vesperini, Enrico; di Criscienzo, Marcella
2017-08-01
The colour-magnitude diagrams of many Magellanic Cloud clusters (with ages up to 2 billion years) display extended turnoff regions where the stars leave the main sequence, suggesting the presence of multiple stellar populations with ages that may differ even by hundreds of millions of years 1,2,3 . A strongly debated question is whether such an extended turnoff is instead due to populations with different stellar rotations3,4,5,6 . The recent discovery of a 'split' main sequence in some younger clusters (~80-400 Myr) added another piece to this puzzle. The blue side of the main sequence is consistent with slowly rotating stellar models, and the red side consistent with rapidly rotating models7,8,9,10. However, a complete theoretical characterization of the observed colour-magnitude diagram also seemed to require an age spread9. We show here that, in the three clusters so far analysed, if the blue main-sequence stars are interpreted with models in which the stars have always been slowly rotating, they must be ~30% younger than the rest of the cluster. If they are instead interpreted as stars that were initially rapidly rotating but have later slowed down, the age difference disappears, and this 'braking' also helps to explain the apparent age differences of the extended turnoff. The age spreads in Magellanic Cloud clusters are thus a manifestation of rotational stellar evolution. Observational tests are suggested.
Using White Dwarf Companions of Blue Stragglers to Constrain Mass Transfer Physics
NASA Astrophysics Data System (ADS)
Gosnell, Natalie M.; Leiner, Emily; Geller, Aaron M.; Knigge, Christian; Mathieu, Robert D.; Sills, Alison; Leigh, Nathan
2018-06-01
Complete membership studies of old open clusters reveal that 25% of the evolved stars follow pathways in stellar evolution that are impacted by binary evolution. Recent studies show that the majority of blue straggler stars, traditionally defined to be stars brighter and bluer than the corresponding main sequence turnoff, are formed through mass transfer from a giant star onto a main sequence companion, resulting in a white dwarf in a binary system with a blue straggler. We will present constraints on the histories and mass transfer efficiencies for two blue straggler-white dwarf binaries in open cluster NGC 188. The constraints are a result of measuring white dwarf cooling temperatures and surface gravities with HST COS far-ultraviolet spectroscopy. This information sets both the timeline for mass transfer and the stellar masses in the pre-mass transfer binary, allowing us to constrain aspects of the mass transfer physics. One system is formed through Case C mass transfer, leaving a CO-core white dwarf, and provides an interesting test case for mass transfer from an asymptotic giant branch star in an eccentric system. The other system formed through Case B mass transfer, leaving a He-core white dwarf, and challenges our current understanding of the expected regimes for stable mass transfer from red giant branch stars.
NASA Astrophysics Data System (ADS)
Jiang, Dengkai; Chen, Xuefei; Li, Lifang; Han, Zhanwen
2017-11-01
Two blue-straggler sequences discovered in globular cluster M30 provide a strong constraint on the formation mechanisms of blue stragglers. We study the formation of blue-straggler binaries through binary evolution, and find that binary evolution can contribute to the blue stragglers in both of the sequences. Whether a blue-straggler is located in the blue sequence or red sequence depends on the contribution of the mass donor to the total luminosity of the binary, which is generally observed as a single star in globular clusters. The blue stragglers in the blue sequence have a cool white dwarf companion, while the majority (˜60%) of the objects in the red sequence are binaries that are still experiencing mass transfer. However, there are also some objects for which the donors have just finished the mass transfer (the stripped-core stars, ˜10%) or the blue stragglers (the accretors) have evolved away from the blue sequence (˜30%). Meanwhile, W UMa contact binaries found in both sequences may be explained by various mass ratios, that is, W UMa contact binaries in the red sequence have two components with comparable masses (e.g., mass ratio q ˜ 0.3-1.0), while those in the blue sequence have low mass ratios (e.g., q< 0.3). However, the fraction of the blue sequence in M30 cannot be reproduced by binary population synthesis if we assumed the initial parameters of a binary sample to be the same as those of the field. This possibly indicates that dynamical effects on binary systems are very important in globular clusters.
Stellar evolution of high mass based on the Ledoux criterion for convection
NASA Technical Reports Server (NTRS)
Stothers, R.; Chin, C.
1972-01-01
Theoretical evolutionary sequences of models for stars of 15 and 30 solar masses were computed from the zero-age main sequence to the end of core helium burning. During the earliest stages of core helium depletion, the envelope rapidly expands into the red-supergiant configuration. At 15 solar mass, a blue loop on the H-R diagram ensues if the initial metals abundance, initial helium abundance, or C-12 + alpha particle reaction rate is sufficiently large, or if the 3-alpha reaction rate is sufficiently small. These quantities affect the opacity of the base of the outer convection zone, the mass of the core, and the thermal properties of the core. The blue loop occurs abruptly and fully developed when the critical value of any of these quantities is exceeded, and the effective temperature range and fraction of the lifetime of core helium burning during the slow phase of the blue loop vary surprisingly little. At 30 solar mass no blue loop occurs for any reasonable set of input parameters.
Spectroscopic and asteroseismic analysis of the remarkable main-sequence A star KIC 11145123
NASA Astrophysics Data System (ADS)
Takada-Hidai, Masahide; Kurtz, Donald W.; Shibahashi, Hiromoto; Murphy, Simon J.; Takata, Masao; Saio, Hideyuki; Sekii, Takashi
2017-10-01
A spectroscopic analysis was carried out to clarify the properties of KIC 11145123 - the first main-sequence star with a directly measured core-to-surface rotation profile - based on spectra observed with the High Dispersion Spectrograph (HDS) of the Subaru telescope. The atmospheric parameters (Teff = 7600 K, log g = 4.2, ξ = 3.1 km s-1 and [Fe/H] = -0.71 dex), the radial and rotation velocities, and elemental abundances were obtained by analysing line strengths and fitting line profiles, which were calculated with a 1D LTE model atmosphere. The main properties of KIC 11145123 are: (1) a low [Fe/H] = -0.71 ± 0.11 dex and a high radial velocity of -135.4 ± 0.2 km s-1. These are remarkable among late-A stars. Our best asteroseismic models with this low [Fe/H] have slightly high helium abundance and low masses of 1.4 M⊙. All of these results strongly suggest that KIC 11145123 is a Population II blue straggler; (2) the projected rotation velocity confirms the asteroseismically predicted slow rotation of the star; (3) comparisons of abundance patterns between KIC 11145123 and Am, Ap, and blue stragglers show that KIC 11145123 is neither an Am star nor an Ap star, but has abundances consistent with a blue straggler. We conclude that the remarkably long 100-d rotation period of this star is a consequence of it being a blue straggler, but both pathways for the formation of blue stragglers - merger and mass loss in a binary system - pose difficulties for our understanding of the exceedingly slow rotation. In particular, we show that there is no evidence of any secondary companion star, and we put stringent limits on the possible mass of any such purported companion through the phase modulation technique.
High-resolution Imaging of PHIBSS z ˜ 2 Main-sequence Galaxies in CO J = 1 → 0
NASA Astrophysics Data System (ADS)
Bolatto, A. D.; Warren, S. R.; Leroy, A. K.; Tacconi, L. J.; Bouché, N.; Förster Schreiber, N. M.; Genzel, R.; Cooper, M. C.; Fisher, D. B.; Combes, F.; García-Burillo, S.; Burkert, A.; Bournaud, F.; Weiss, A.; Saintonge, A.; Wuyts, S.; Sternberg, A.
2015-08-01
We present Karl Jansky Very Large Array observations of the CO J=1-0 transition in a sample of four z˜ 2 main-sequence galaxies. These galaxies are in the blue sequence of star-forming galaxies at their redshift, and are part of the IRAM Plateau de Bure HIgh-z Blue Sequence Survey which imaged them in CO J=3-2. Two galaxies are imaged here at high signal-to-noise, allowing determinations of their disk sizes, line profiles, molecular surface densities, and excitation. Using these and published measurements, we show that the CO and optical disks have similar sizes in main-sequence galaxies, and in the galaxy where we can compare CO J=1-0 and J=3-2 sizes we find these are also very similar. Assuming a Galactic CO-to-H2 conversion, we measure surface densities of {{{Σ }}}{mol}˜ 1200 {M}⊙ pc-2 in projection and estimate {{{Σ }}}{mol}˜ 500-900 {M}⊙ pc-2 deprojected. Finally, our data yields velocity-integrated Rayleigh-Jeans brightness temperature line ratios r31 that are approximately at unity. In addition to the similar disk sizes, the very similar line profiles in J=1-0 and J=3-2 indicate that both transitions sample the same kinematics, implying that their emission is coextensive. We conclude that in these two main-sequence galaxies there is no evidence for significant excitation gradients or a large molecular reservoir that is diffuse or cold and not involved in active star formation. We suggest that r31 in very actively star-forming galaxies is likely an indicator of how well-mixed the star formation activity and the molecular reservoir are.
The 100 brigthest Blue Straggler Stars.
NASA Astrophysics Data System (ADS)
Morales Durán, C.; Llorente de Andrés, F.; Ahumada, J. A.
2015-05-01
Blue straggler stars (BSS) are characterized by their appearance in the CMD of globular and open clusters, in the Main Sequence extension, above the turn-off and blueward of this. In accordance with the Standard Theory of stellar evolution, BSS should be out of the Main Sequence and over the Giant Branch if they really belong to the cluster and are formed at the same time than the rest of cluster stars. There are several theories that try to explain the existence of BSS but at present prevails the idea that they can be the product of mass transfer in binaries (McCrea, 1964), and the luminosity of the receiver star is incremented in such a way that now it is over the Main Sequence turn-off point of its cluster. Also it is believed that they are the result of stellar fussion of two or several stars, specially in dense systems as the globular cluster nucleus. This work is focalised in all the BSS brihgter the V = 10 mag. that we have been able to identify in open clusters. It is a sample unprecedented by its number and as well it is a sample with plentiful observational information, it is why we hope to be able to assure their membership to the parent cluster and obtain reliable information about their possible origin.
Blue stragglers in the core of the globular cluster 47 Tucanae
NASA Technical Reports Server (NTRS)
Paresce, F.; Meylan, G.; Shara, M.; Baxter, D.; Greenfield, P.
1991-01-01
High-resolution observations of the core of the globular cluster 47 Tucanae with the Faint Object Camera on the Hubble Space Telescope reveal a high density of 'blue straggler' stars, occupying the upper end of the main sequence from which all stars in the cluster should have long since evolved. Their presence in the dense core supports the hypothesis that they formed by stellar collision and coalescence, and, as the heaviest objects in the cluster, have drifted to the core.
Supernova 1987A - the evolution from blue to red
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tuchman, Y.; Wheeler, J.C.
1989-09-01
The evolution of stars with mass comparable to that of the progenitor of SN 1987A from the main sequence to the Hayashi track is critically examined to determine why some models evolve to the red on nuclear time scales, some on thermal time scales, and some not at all. Thermal equilibrium solutions to a parametrized series of structural models with active hydrogen burning shells have two stable solutions with different T(eff) for the same helium core M(He) mass and a minimum M(He) below which no blue thermal equlibrium solution is possible. The dependence of the equilibrium solutions on stellar mass,more » envelope composition, and mass loss are investigated. The solutions quantitatively account for the 'gap' in the HR diagrams of massive stars in the Galaxy and LMC and suggest that the outer envelopes are not substantially enriched in helium during the first passage from the main sequence to the Hayashi track. 23 refs.« less
On the non-variability of HR 7653 (15 Vul) based on BRITE data
NASA Astrophysics Data System (ADS)
Smalley, B.; Paunzen, E.; Lüftinger, T.; Moffat, A. F. J.; Pigulski, A.; Rucinski, S.; Sikora, J.; Wade, G. A.; Weiss, W.; BEST
2018-02-01
We present space-based BRITE photometric observations of the metallic line (CP1) star HR 7653 (15 Vul). This chemically peculiar star of the upper main sequence was suspected to show variability due to rotation and a magnetic field. Such a variability is quite unusual among the, in general, non-magnetic CP1 stars. We investigated the astrophysical parameters of HR 7653 placing it close to the terminal age main sequence or even in the subgiant phase. The longest BRITE data set has a time base of 18.01 d from which we conclude that there are no coherent long-period variations (>1 d) visible above 2.1 mmag in the red and 6.6 mmag in the blue. Furthermore, we searched for δ Scuti type pulsations. On the basis of a discrete Fourier analysis method, we find no peaks in the Fourier spectra above 0.5 mmag and 8.6 mmag, for the red and blue filters, respectively.
NASA Astrophysics Data System (ADS)
Guo, Rui; Hao, Cai-Na; Xia, X. Y.; Mao, Shude; Shi, Yong
2016-07-01
With the aim of exploring the fast evolutionary path from the blue cloud of star-forming galaxies to the red sequence of quiescent galaxies in the local universe, we select a local advanced merging infrared luminous and ultraluminous galaxy (adv-merger (U)LIRGs) sample and perform careful dust extinction corrections to investigate their positions in the star formation rate-M *, u - r, and NUV - r color-mass diagrams. The sample consists of 89 (U)LIRGs at the late merger stage, obtained from cross-correlating the Infrared Astronomical Satellite Point Source Catalog Redshift Survey and 1 Jy ULIRGs samples with the Sloan Digital Sky Survey DR7 database. Our results show that 74 % +/- 5 % of adv-merger (U)LIRGs are localized above the 1σ line of the local star-forming galaxy main sequence. We also find that all adv-merger (U)LIRGs are more massive than and as blue as the blue cloud galaxies after corrections for Galactic and internal dust extinctions, with 95 % +/- 2 % and 81 % +/- 4 % of them outside the blue cloud on the u - r and NUV - r color-mass diagrams, respectively. These results, combined with the short timescale for exhausting the molecular gas reservoir in adv-merger (U)LIRGs (3× {10}7 to 3× {10}8 years), imply that the adv-merger (U)LIRGs are likely at the starting point of the fast evolutionary track previously proposed by several groups. While the number density of adv-merger (U)LIRGs is only ˜ 0.1 % of the blue cloud star-forming galaxies in the local universe, this evolutionary track may play a more important role at high redshift.
THE K2 M67 STUDY: AN EVOLVED BLUE STRAGGLER IN M67 FROM K2 MISSION ASTEROSEISMOLOGY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leiner, Emily; Mathieu, Robert D.; Stello, Dennis
Yellow straggler stars (YSSs) fall above the subgiant branch in optical color–magnitude diagrams (CMDs), between the blue stragglers and the red giants. YSSs may represent a population of evolved blue stragglers, but none have the direct and precise mass and radius measurements needed to determine their evolutionary states and formation histories. Here we report the first asteroseismic mass and radius measurements of such a star, the yellow straggler S1237 in the open cluster M67. We apply asteroseismic scaling relations to a frequency analysis of the Kepler K2 light curve and find a mass of 2.9 ± 0.2 M {sub ⊙}more » and a radius of 9.2 ± 0.2 R{sub ⊙}. This is more than twice the mass of the main-sequence turnoff in M67, suggesting that S1237 is indeed an evolved blue straggler. S1237 is the primary in a spectroscopic binary. We update the binary orbital solution and use spectral energy distribution fitting to constrain the CMD location of the secondary star. We find that the secondary is likely an upper main-sequence star near the turnoff, but a slightly hotter blue straggler companion is also possible. We then compare the asteroseismic mass of the primary to its mass from CMD fitting, finding that the photometry implies a mass and radius more than 2 σ below the asteroseismic measurement. Finally, we consider formation mechanisms for this star and suggest that S1237 may have formed from dynamical encounters resulting in stellar collisions or a binary merger.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schombert, James; McGaugh, Stacy, E-mail: jschombe@uoregon.edu, E-mail: stacy.mcgaugh@case.edu
2015-09-15
We present WFC3 observations of three low surface brightness (LSB) galaxies from the Schombert et al. LSB catalog that are within 11 Mpc of the Milky Way. Deep imaging at F336W, F555W, and F814W allow the construction of the V − I color–magnitude diagrams (CMD) to M{sub I} = −2. Overall 1869, 465, and 501 stellar sources are identified in the three LSB galaxies F415-3, F608-1, and F750-V1, respectively. The spatial distribution of young blue stars matches the Hα maps from ground-based imaging, indicating that star formation in LSB galaxies follows the same style as in other irregular galaxies. Severalmore » star complexes are identified, matching regions of higher surface brightness as seen from ground-based imaging. The CMD for each LSB galaxy has a similar morphology to Local Volume (LV) dwarf galaxies (i.e., a blue main sequence, blue and red He burning branches, and asymptotic giant branch (AGB) stars). The LSB CMD’s distinguish themselves from nearby dwarf CMD’s by having a higher proportion of blue main sequence stars and fewer AGB stars than expected from their mean metallicities. Current [Fe/H] values below −0.6 are deduced from the position of the red helium-burning branch (rHeB) stars in the V − I diagram. The distribution of stars on the blue helium-burning branch (bHeB) and rHeB from the U − V and V − I CMD indicate a history of constant star formation for the last 100 Myr.« less
Building an Unusual White-Dwarf Duo
NASA Astrophysics Data System (ADS)
Kohler, Susanna
2016-09-01
A new study has examined how the puzzling wide binary system HS 2220+2146 which consists of two white dwarfs orbiting each other might have formed. This system may be an example of a new evolutionary pathway for wide white-dwarf binaries.Evolution of a BinaryMore than 100 stellar systems have been discovered consisting of two white dwarfs in a wide orbit around each other. How do these binaries form? In the traditional picture, the system begins as a binary consisting of two main-sequence stars. Due to the large separation between the stars, the stars evolve independently, each passing through the main-sequence and giant branches and ending their lives as white dwarfs.An illustration of a hierarchical triple star system, in which two stars orbit each other, and a third star orbits the pair. [NASA/JPL-Caltech]Because more massive stars evolve more quickly, the most massive of the two stars in a binary pair should be the first to evolve into a white dwarf. Consequently, when we observe a double-white-dwarf binary, its usually a safe bet that the more massive of the two white dwarfs will also be the older and cooler of the pair, since it should have formed first.But in the case of the double-white-dwarf binary HS 2220+2146, the opposite is true: the more massive of the two white dwarfs appears to be the younger and hotter of the pair. If it wasnt created in the traditional way, then how did this system form?Two From Three?Led by Jeff Andrews (Foundation for Research and Technology-Hellas, Greece and Columbia University), a team of scientists recently examined this system more carefully, analyzing its spectra to confirm our understanding of the white dwarfs temperatures and masses.Based on their observations, Andrews and collaborators determined that there are no hidden additional companions that could have caused the unusual evolution of this system. Instead, the team proposed that this unusual binary might be an example of an evolutionary channel that involves three stars.The authors proposed formation scenario for H220+2146. In this picture, the inner binary merges to form a blue straggler. This star and the remaining main-sequence star then evolve independently into white dwarfs, forming the system observed today. [Andrews et al. 2016]An Early MergerIn the model the authors propose for HS 2220+2146, the binary system began as a hierarchical triple system of main-sequence stars. The innermost binary then merged to form a large star known as a blue straggler a star that, due to the merger, will evolve more slowly than its larger mass implies it should.The blue straggler and the remaining main-sequence star, still in a wide orbit, then continued to evolve independently of each other. The smaller star ended its main-sequence lifetime and became a white dwarf first, followed by the more massive but slowly evolving blue straggler thus forming the system we observe today.If the authors model is correct, then HS 2220+2146 would be the first binary double white dwarf known to have formed through this channel. ESAs Gaia mission, currently underway, is expected to discover up to a million new white dwarfs, many of which will likely be in wide binary systems. Among these, we may well find many other systems like HS 2220+2146 that formed in the same way.CitationJeff J. Andrews et al 2016 ApJ 828 38. doi:10.3847/0004-637X/828/1/38
NASA Technical Reports Server (NTRS)
Fanelli, Michael N.; O'Connell, Robert W.; Thuan, Trinh X.
1988-01-01
An initial attempt to apply optimizing spectral synthesis techniques to the far-UV spectra of blue compact galaxies (BCGs) is presented. The far-UV absorption-line spectra of the galaxies are clearly composite, with the signatures of the main-sequence types between O3 and mid-A. Most of the low-ionization absorption lines have a stellar origin. The Si IV and C IV features in several objects have P Cygni profiles. In Haro I the strength of Si IV indicates a significant blue supergiant population. The metal-poor blue compact dwarf Mrk 209 displays weak absorption lines, evidence that the stellar component has the same low metallicity as observed in the ionized gas. Good fits to the data are obtained the technique of optimizing population synthesis. The solutions yield stellar luminosity functions which display large discontinuities, indicative of discrete star formation episodes or bursts. The amount of UV extinction is low.
BLUE STRAGGLERS IN GLOBULAR CLUSTER 47 TUCANAE
NASA Technical Reports Server (NTRS)
2002-01-01
The core of globular cluster 47 Tucanae is home to many blue stragglers, rejuvenated stars that glow with the blue light of young stars. A ground-based telescope image (on the left) shows the entire crowded core of 47 Tucanae, located 15,000 light-years away in the constellation Tucana. Peering into the heart of the globular cluster's bright core, the Hubble Space Telescope's Wide Field and Planetary Camera 2 separated the dense clump of stars into many individual stars (image on right). Some of these stars shine with the light of old stars; others with the blue light of blue stragglers. The yellow circles in the Hubble telescope image highlight several of the cluster's blue stragglers. Analysis for this observation centered on one massive blue straggler. Astronomers theorize that blue stragglers are formed either by the slow merger of stars in a double-star system or by the collision of two unrelated stars. For the blue straggler in 47 Tucanae, astronomers favor the slow merger scenario. This image is a 3-color composite of archival Hubble Wide Field and Planetary Camera 2 images in the ultraviolet (blue), blue (green), and violet (red) filters. Color tables were assigned and scaled so that the red giant stars appear orange, main-sequence stars are white/green, and blue stragglers are appropriately blue. The ultraviolet images were taken on Oct. 25, 1995, and the blue and violet images were taken on Sept. 1, 1995. Credit: Rex Saffer (Villanova University) and Dave Zurek (STScI), and NASA
A binary origin for 'blue stragglers' in globular clusters.
Knigge, Christian; Leigh, Nathan; Sills, Alison
2009-01-15
Blue stragglers in globular clusters are abnormally massive stars that should have evolved off the stellar main sequence long ago. There are two known processes that can create these objects: direct stellar collisions and binary evolution. However, the relative importance of these processes has remained unclear. In particular, the total number of blue stragglers found in a given cluster does not seem to correlate with the predicted collision rate, providing indirect support for the binary-evolution model. Yet the radial distributions of blue stragglers in many clusters are bimodal, with a dominant central peak: this has been interpreted as an indication that collisions do dominate blue straggler production, at least in the high-density cluster cores. Here we report that there is a clear, but sublinear, correlation between the number of blue stragglers found in a cluster core and the total stellar mass contained within it. From this we conclude that most blue stragglers, even those found in cluster cores, come from binary systems. The parent binaries, however, may themselves have been affected by dynamical encounters. This may be the key to reconciling all of the seemingly conflicting results found to date.
Evolution of massive stars in very young clusters and associations
NASA Technical Reports Server (NTRS)
Stothers, R. B.
1985-01-01
Statistics concerning the stellar content of young galactic clusters and associations which show well defined main sequence turnups have been analyzed in order to derive information about stellar evolution in high-mass galaxies. The analytical approach is semiempirical and uses natural spectroscopic groups of stars on the H-R diagram together with the stars' apparent magnitudes. The new approach does not depend on absolute luminosities and requires only the most basic elements of stellar evolution theory. The following conclusions are offered on the basis of the statistical analysis: (1) O-tupe main-sequence stars evolve to a spectral type of B1 during core hydrogen burning; (2) most O-type blue stragglers are newly formed massive stars burning core hydrogen; (3) supergiants lying redward of the main-sequence turnup are burning core helium; and most Wolf-Rayet stars are burning core helium and originally had masses greater than 30-40 solar mass. The statistics of the natural spectroscopic stars in young galactic clusters and associations are given in a table.
DuOCam: A Two-Channel Camera for Simultaneous Photometric Observations of Stellar Clusters
NASA Astrophysics Data System (ADS)
Maier, Erin R.; Witt, Emily; Depoy, Darren L.; Schmidt, Luke M.
2017-01-01
We have designed the Dual Observation Camera (DuOCam), which uses commercial, off-the-shelf optics to perform simultaneous photometric observations of astronomical objects at red and blue wavelengths. Collected light enters DuOCam’s optical assembly, where it is collimated by a negative doublet lens. It is then separated by a 45 degree blue dichroic filter (transmission bandpass: 530 - 800 nm, reflection bandpass: 400 - 475 nm). Finally, the separated light is focused by two identical positive doublet lenses onto two independent charge-coupled devices (CCDs), the SBIG ST-8300M and the SBIG STF-8300M. This optical assembly converts the observing telescope to an f/11 system, which balances maximum field of view with optimum focus. DuOCam was commissioned on the McDonald Observatory 0.9m, f/13.5 telescope from July 21st - 24th, 2016. Observations of three globular and three open stellar clusters were carried out. The resulting data were used to construct R vs. B-R color magnitude diagrams for a selection of the observed clusters. The diagrams display the characteristic evolutionary track for a stellar cluster, including the main sequence and main sequence turn-off.
A Rapidly Moving Shell in the Orion Nebula
NASA Technical Reports Server (NTRS)
Walter, Donald K.; O'Dell, C. R.; Hu, Xihai; Dufour, Reginald J.
1995-01-01
A well-resolved elliptical shell in the inner Orion Nebula has been investigated by monochromatic imaging plus high- and low-resolution spectroscopy. We find that it is of low ionization and the two bright ends are moving at -39 and -49 km/s with respect to OMC-1. There is no central object, even in the infrared J bandpass although H2 emission indicates a possible association with the nearby very young pre-main-sequence star J&W 352, which is one of the youngest pre-main-sequence stars in the inner Orion Nebula. Many of the characteristics of this object (low ionization, blue shift) are like those of the Herbig-Haro objects, although the symmetric form would make it an unusual member of that class.
Optical spectroscopy of the blue supergiant Sk-69° 279 and its circumstellar shell with SALT
NASA Astrophysics Data System (ADS)
Gvaramadze, V. V.; Kniazev, A. Y.; Maryeva, O. V.; Berdnikov, L. N.
2018-02-01
We report the results of optical spectroscopy of the blue supergiant Sk-69° 279 and its circular shell in the Large Magellanic Cloud (LMC) with the Southern African Large Telescope (SALT). We classify Sk-69° 279 as an O9.2 Iaf star and analyse its spectrum by using the stellar atmosphere code CMFGEN, obtaining a stellar temperature of ≈30 kK, a luminosity of log (L*/ L⊙) = 5.54, a mass-loss rate of log (\\dot{M}/ M_{⊙} yr^{-1}) = -5.26, and a wind velocity of 800km s-1. We found also that Sk-69° 279 possesses an extended atmosphere with an effective temperature of ≈24 kK and that its surface helium and nitrogen abundances are enhanced, respectively, by factors of ≈2 and 20-30. This suggests that either Sk-69° 279 was initially a (single) fast-rotating ( ≳ 400 km s- 1) star, which only recently evolved off the main sequence, or that it is a product of close binary evolution. The long-slit spectroscopy of the shell around Sk-69° 279 revealed that its nitrogen abundance is enhanced by the same factor as the stellar atmosphere, which implies that the shell is composed mostly of the CNO processed material lost by the star. Our findings support previous propositions that some massive stars can produce compact circumstellar shells and, presumably, appear as luminous blue variables while they are still on the main sequence or have only recently left it.
A mass transfer origin for blue stragglers in NGC 188 as revealed by half-solar-mass companions.
Geller, Aaron M; Mathieu, Robert D
2011-10-19
In open star clusters, where all members formed at about the same time, blue straggler stars are typically observed to be brighter and bluer than hydrogen-burning main-sequence stars, and therefore should already have evolved into giant stars and stellar remnants. Correlations between blue straggler frequency and cluster binary star fraction, core mass and radial position suggest that mass transfer or mergers in binary stars dominates the production of blue stragglers in open clusters. Analytic models, detailed observations and sophisticated N-body simulations, however, argue in favour of stellar collisions. Here we report that the blue stragglers in long-period binaries in the old (7 × 10(9)-year) open cluster NGC 188 have companions with masses of about half a solar mass, with a surprisingly narrow mass distribution. This conclusively rules out a collisional origin, as the collision hypothesis predicts a companion mass distribution with significantly higher masses. Mergers in hierarchical triple stars are marginally permitted by the data, but the observations do not favour this hypothesis. The data are highly consistent with a mass transfer origin for the long-period blue straggler binaries in NGC 188, in which the companions would be white dwarfs of about half a solar mass.
Cloning and expression of recombinant adhesive protein Mefp-1 of the blue mussel, Mytilus edulis
Silverman, Heather G.; Roberto, Francisco F.
2006-01-17
The present invention comprises a Mytilus edulis cDNA sequenc having a nucleotide sequence that encodes for the Mytilus edulis foot protein-1 (Mefp-1), an example of a mollusk foot protein. Mefp-1 is an integral component of the blue mussels' adhesive protein complex, which allows the mussel to attach to objects underwater. The isolation, purification and sequencing of the Mefp-1 gene will allow researchers to produce Mefp-1 protein using genetic engineering techniques. The discovery of Mefp-1 gene sequence will also allow scientists to better understand how the blue mussel creates its waterproof adhesive protein complex.
Photometric and Structural Properties of NGC 6544: A Combined VVV-Hubble Space Telescope Study
NASA Astrophysics Data System (ADS)
Cohen, Roger E.; Mauro, Francesco; Geisler, Doug; Moni Bidin, Christian; Dotter, Aaron; Bonatto, Charles
2014-07-01
We combine archival Hubble Space Telescope imaging with wide-field near-infrared photometry to study the neglected metal-poor Galactic globular cluster NGC 6544. A high spatial resolution map of differential reddening over the inner portion of the cluster is constructed, revealing variations of up to half of the total reddening, and the resulting corrected color-magnitude diagrams reveal a sparse blue horizontal branch and centrally concentrated blue straggler population, verified via relative proper motions. Using the corrected photometry to investigate the cluster distance, reddening, and age via direct comparison to well-calibrated photometry of clusters with similar metallicities, we estimate (m - M)0 = 11.96, E(B - V) = 0.79, and an age coeval with M13 to within the relevant uncertainties. Although our data are insufficient to place tight constraints on the reddening law toward NGC 6544, we find no strong evidence that it is non-standard at optical or near-infrared wavelengths. We also provide near-infrared fiducial sequences extending nearly 2 mag below the cluster main sequence turnoff, generated from a statistically decontaminated sample of cluster stars. Lastly, we redetermine the cluster center and construct a radial number density profile which is well fit by an atypically flat power law with a slope of about 1.7. We discuss this result, together with a flattened main sequence luminosity function and inverted mass function, in the context of mass segregation and tidal stripping via interactions with Milky Way potential.
COS Spectroscopy of White Dwarf Companions to Blue Stragglers
NASA Astrophysics Data System (ADS)
Gosnell, Natalie M.; Geller, Aaron M.; Knigge, Christian; Mathieu, Robert D.; Sills, Alison; Leiner, Emily; Leigh, Nathan
2017-01-01
Complete membership studies of open stellar clusters reveal that 25% of the evolved stars follow alternative pathways in stellar evolution, meaning something in the history of these stars changed their composition or mass (or both). In order to draw a complete picture of stellar evolution we must include these canonically "strange" stars in our definition of standard stellar populations. The formation mechanism of blue straggler stars, traditionally defined to be brighter and bluer than the main sequence turnoff in a star cluster, has been an outstanding question for almost six decades. Recent Hubble Space Telescope (HST) far-ultraviolet (far-UV) observations directly reveal that the blue straggler stars in the old (7 Gyr) open cluster NGC 188 are predominantly formed through mass transfer. We will present HST far-UV COS spectroscopy of white dwarf companions to blue stragglers. These white dwarfs are the remnants of the mass transfer formation process. The effective temperatures and surface gravities of the white dwarfs delineate the timeline of blue straggler formation in this cluster. The existence of these binaries in a well-studied cluster environment provides an unprecedented opportunity to observationally constrain mass transfer models and inform our understanding of many other alternative pathway stellar products.
Gao, Ya; Wang, Shu; Fu, Mingjia; Zhong, Guolin
2013-09-04
To determine blue-light induced expression of S-adenosyl-L-homocysteine hydrolase-like (sahhl) gene in fungus Mucor amphibiorum RCS1. In the random process of PCR, a sequence of 555 bp was obtained from M. amphibiorum RCS1. The 555 bp sequence was labeled with digoxin to prepare the probe for northern hybridization. By northern hybridization, the transcription of sahhl gene was analyzed in M. amphibiorum RCS1 mycelia culture process from darkness to blue light to darkness. Simultaneously real-time PCR method was used to the sahhl gene expression analysis. Compared with the sequence of sahh gene from Homo sapiens, Mus musculus and some fungi species, a high homology of the 555 bp sequence was confirmed. Therefore, the preliminary confirmation has supported that the 555 bp sequence should be sahhl gene from M. amphibiorum RCS1. Under the dark pre-culture in 24 h, a large amounts of transcript of sahhl gene in the mycelia can be detected by northern hybridization and real-time PCR in the condition of 24 h blue light. But a large amounts of transcript of sahhl gene were not found in other detection for the dark pre-culture of 48 h, even though M. amphibiorum RCS1 mycelia were induced by blue light. Blue light can induce the expression of sahhl gene in the vigorous growth of M. amphibiorum RCS1 mycelia.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thilker, David A.; Bianchi, Luciana; Schiminovich, David
We have discovered recent star formation in the outermost portion ((1-4) x R {sub 25}) of the nearby lenticular (S0) galaxy NGC 404 using Galaxy Evolution Explorer UV imaging. FUV-bright sources are strongly concentrated within the galaxy's H I ring (formed by a merger event according to del RIo et al.), even though the average gas density is dynamically subcritical. Archival Hubble Space Telescope imaging reveals resolved upper main-sequence stars and conclusively demonstrates that the UV light originates from recent star formation activity. We present FUV, NUV radial surface brightness profiles, and integrated magnitudes for NGC 404. Within the ring,more » the average star formation rate (SFR) surface density ({Sigma}{sub SFR}) is {approx}2.2 x 10{sup -5} M {sub sun} yr{sup -1} kpc{sup -2}. Of the total FUV flux, 70% comes from the H I ring which is forming stars at a rate of 2.5 x 10{sup -3} M {sub sun} yr{sup -1}. The gas consumption timescale, assuming a constant SFR and no gas recycling, is several times the age of the universe. In the context of the UV-optical galaxy color-magnitude diagram, the presence of the star-forming H I ring places NGC 404 in the green valley separating the red and blue sequences. The rejuvenated lenticular galaxy has experienced a merger-induced, disk-building excursion away from the red sequence toward bluer colors, where it may evolve quiescently or (if appropriately triggered) experience a burst capable of placing it on the blue/star-forming sequence for up to {approx}1 Gyr. The green valley galaxy population is heterogeneous, with most systems transitioning from blue to red but others evolving in the opposite sense due to acquisition of fresh gas through various channels.« less
NASA Astrophysics Data System (ADS)
Marion, G. H.; Brown, Peter J.; Vinkó, Jozsef; Silverman, Jeffrey M.; Sand, David J.; Challis, Peter; Kirshner, Robert P.; Wheeler, J. Craig; Berlind, Perry; Brown, Warren R.; Calkins, Michael L.; Camacho, Yssavo; Dhungana, Govinda; Foley, Ryan J.; Friedman, Andrew S.; Graham, Melissa L.; Howell, D. Andrew; Hsiao, Eric Y.; Irwin, Jonathan M.; Jha, Saurabh W.; Kehoe, Robert; Macri, Lucas M.; Maeda, Keiichi; Mandel, Kaisey; McCully, Curtis; Pandya, Viraj; Rines, Kenneth J.; Wilhelmy, Steven; Zheng, Weikang
2016-04-01
We report evidence for excess blue light from the Type Ia supernova (Sn Ia) SN 2012cg at 15 and 16 days before maximum B-band brightness. The emission is consistent with predictions for the impact of the supernova on a non-degenerate binary companion. This is the first evidence for emission from a companion to a normal SN Ia. Sixteen days before maximum light, the B-V color of SN 2012cg is 0.2 mag bluer than for other normal SN Ia. At later times, this supernova has a typical SN Ia light curve, with extinction-corrected {M}B=-19.62+/- 0.02 mag and {{Δ }}{m}15(B)=0.86+/- 0.02. Our data set is extensive, with photometry in seven filters from five independent sources. Early spectra also show the effects of blue light, and high-velocity features are observed at early times. Near maximum, the spectra are normal with a silicon velocity vSi = -10,500 km s-1. Comparing the early data with models by Kasen favors a main-sequence companion of about six solar masses. It is possible that many other SN Ia have main-sequence companions that have eluded detection because the emission from the impact is fleeting and faint.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Calamida, A.; Saha, A.; Strampelli, G.
2017-04-01
We present a multi-band photometric catalog of ≈1.7 million cluster members for a field of view of ≈2° × 2° across ω Cen. Photometry is based on images collected with the Dark Energy Camera on the 4 m Blanco telescope and the Advanced Camera for Surveys on the Hubble Space Telescope . The unprecedented photometric accuracy and field coverage allowed us, for the first time, to investigate the spatial distribution of ω Cen multiple populations from the core to the tidal radius, confirming its very complex structure. We found that the frequency of blue main-sequence stars is increasing compared to red main-sequencemore » stars starting from a distance of ≈25′ from the cluster center. Blue main-sequence stars also show a clumpy spatial distribution, with an excess in the northeast quadrant of the cluster pointing toward the direction of the Galactic center. Stars belonging to the reddest and faintest red-giant branch also show a more extended spatial distribution in the outskirts of ω Cen, a region never explored before. Both these stellar sub-populations, according to spectroscopic measurements, are more metal-rich compared to the cluster main stellar population. These findings, once confirmed, make ω Cen the only stellar system currently known where metal-rich stars have a more extended spatial distribution compared to metal-poor stars. Kinematic and chemical abundance measurements are now needed for stars in the external regions of ω Cen to better characterize the properties of these sub-populations.« less
NASA Astrophysics Data System (ADS)
Calamida, A.; Strampelli, G.; Rest, A.; Bono, G.; Ferraro, I.; Saha, A.; Iannicola, G.; Scolnic, D.; James, D.; Smith, C.; Zenteno, A.
2017-04-01
We present a multi-band photometric catalog of ≈1.7 million cluster members for a field of view of ≈2° × 2° across ω Cen. Photometry is based on images collected with the Dark Energy Camera on the 4 m Blanco telescope and the Advanced Camera for Surveys on the Hubble Space Telescope. The unprecedented photometric accuracy and field coverage allowed us, for the first time, to investigate the spatial distribution of ω Cen multiple populations from the core to the tidal radius, confirming its very complex structure. We found that the frequency of blue main-sequence stars is increasing compared to red main-sequence stars starting from a distance of ≈25‧ from the cluster center. Blue main-sequence stars also show a clumpy spatial distribution, with an excess in the northeast quadrant of the cluster pointing toward the direction of the Galactic center. Stars belonging to the reddest and faintest red-giant branch also show a more extended spatial distribution in the outskirts of ω Cen, a region never explored before. Both these stellar sub-populations, according to spectroscopic measurements, are more metal-rich compared to the cluster main stellar population. These findings, once confirmed, make ω Cen the only stellar system currently known where metal-rich stars have a more extended spatial distribution compared to metal-poor stars. Kinematic and chemical abundance measurements are now needed for stars in the external regions of ω Cen to better characterize the properties of these sub-populations. Based on observations made with the Dark Energy Camera (DECam) on the 4 m Blanco telescope (NOAO) under programs 2014A-0327, 2015A-0151, 2016A-0189, PIs: A. Calamida, A. Rest, and on observations made with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
Yasukawa, Hiro; Sato, Aya; Kita, Ayaka; Kodaira, Ken-Ichi; Iseki, Mineo; Takahashi, Tetsuo; Shibusawa, Mami; Watanabe, Masakatsu; Yagita, Kenji
2013-01-01
Complete genome sequencing of Naegleria gruberi has revealed that the organism encodes polypeptides similar to photoactivated adenylyl cyclases (PACs). Screening in the N. australiensis genome showed that the organism also encodes polypeptides similar to PACs. Each of the Naegleria proteins consists of a "sensors of blue-light using FAD" domain (BLUF domain) and an adenylyl cyclase domain (AC domain). PAC activity of the Naegleria proteins was assayed by comparing sensitivities of Escherichia coli cells heterologously expressing the proteins to antibiotics in a dark condition and a blue light-irradiated condition. Antibiotics used in the assays were fosfomycin and fosmidomycin. E. coli cells expressing the Naegleria proteins showed increased fosfomycin sensitivity and fosmidomycin sensitivity when incubated under blue light, indicating that the proteins functioned as PACs in the bacterial cells. Analysis of the N. fowleri genome revealed that the organism encodes a protein bearing an amino acid sequence similar to that of BLUF. A plasmid expressing a chimeric protein consisting of the BLUF-like sequence found in N. fowleri and the adenylyl cyclase domain of N. gruberi PAC was constructed to determine whether the BLUF-like sequence functioned as a sensor of blue light. E. coli cells expressing a chimeric protein showed increased fosfomycin sensitivity and fosmidomycin sensitivity when incubated under blue light. These experimental results indicated that the sequence similar to the BLUF domain found in N. fowleri functioned as a sensor of blue light.
Gaia Reveals Evidence for Merged White Dwarfs
NASA Astrophysics Data System (ADS)
Kilic, Mukremin; Hambly, N. C.; Bergeron, P.; Genest-Beaulieu, C.; Rowell, N.
2018-06-01
We use Gaia Data Release 2 to identify 13,928 white dwarfs within 100 pc of the Sun. The exquisite astrometry from Gaia reveals for the first time a bifurcation in the observed white dwarf sequence in both Gaia and the Sloan Digital Sky Survey (SDSS) passbands. The latter is easily explained by a helium atmosphere white dwarf fraction of 36%. However, the bifurcation in the Gaia colour-magnitude diagram depends on both the atmospheric composition and the mass distribution. We simulate theoretical colour-magnitude diagrams for single and binary white dwarfs using a population synthesis approach and demonstrate that there is a significant contribution from relatively massive white dwarfs that likely formed through mergers. These include white dwarf remnants of main-sequence (blue stragglers) and post-main sequence mergers. The mass distribution of the SDSS subsample, including the spectroscopically confirmed white dwarfs, also shows this massive bump. This is the first direct detection of such a population in a volume-limited sample.
Momonoi, Kazumi; Yoshida, Kumi; Mano, Shoji; Takahashi, Hideyuki; Nakamori, Chihiro; Shoji, Kazuaki; Nitta, Akira; Nishimura, Mikio
2009-08-01
Blue color in flowers is due mainly to anthocyanins, and a considerable part of blue coloration can be attributed to metal-complexed anthocyanins. However, the mechanism of metal ion transport into vacuoles and subsequent flower color development has yet to be fully explored. Previously, we studied the mechanism of blue color development specifically at the bottom of the inner perianth in purple tulip petals of Tulipa gesneriana cv. Murasakizuisho. We found that differences in iron content were associated with the development of blue- and purple-colored cells. Here, we identify a vacuolar iron transporter in T. gesneriana (TgVit1), and characterize the localization and function of this transporter protein in tulip petals. The amino acid sequence of TgVit1 is 85% similar that of the Arabidopsis thaliana vacuolar iron transporter AtVIT1, and also showed similarity to the AtVIT1 homolog in yeast, Ca(2+)-sensitive cross-complementer 1 (CCC1). The gene TgVit1 was expressed exclusively in blue-colored epidermal cells, and protein levels increased with increasing mRNA expression and blue coloration. Transient expression experiments revealed that TgVit1 localizes to the vacuolar membrane, and is responsible for the development of the blue color in purple cells. Expression of TgVit1 in yeast rescued the growth defect of ccc1 mutant cells in the presence of high concentrations of FeSO(4). Our results indicate that TgVit1 plays an essential role in blue coloration as a vacuolar iron transporter in tulip petals. These results suggest a new role for involvement of a vacuolar iron transporter in blue flower color development.
Tardu, Mehmet; Dikbas, Ugur Meric; Baris, Ibrahim; Kavakli, Ibrahim Halil
2016-11-01
Light is one of the main environmental cues that affects the physiology and behavior of many organisms. The effect of light on genome-wide transcriptional regulation has been well-studied in green algae and plants, but not in red algae. Cyanidioschyzon merolae is used as a model red algae, and is suitable for studies on transcriptomics because of its compact genome with a relatively small number of genes. In addition, complete genome sequences of the nucleus, mitochondrion, and chloroplast of this organism have been determined. Together, these attributes make C. merolae an ideal model organism to study the response to light stimuli at the transcriptional and the systems biology levels. Previous studies have shown that light significantly affects cell signaling in this organism, but there are no reports on its blue light- and red light-mediated transcriptional responses. We investigated the direct effects of blue and red light at the transcriptional level using RNA-seq. Blue and red lights were found to regulate 35 % of the total genes in C. merolae. Blue light affected the transcription of genes involved in protein synthesis while red light specifically regulated the transcription of genes involved in photosynthesis and DNA repair. Blue or red light regulated genes involved in carbon metabolism and pigment biosynthesis. Overall, our data showed that red and blue light regulate the majority of the cellular, cell division, and repair processes in C. merolae.
Photometric and structural properties of NGC 6544: A combined VVV-Hubble space telescope study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cohen, Roger E.; Mauro, Francesco; Geisler, Doug
We combine archival Hubble Space Telescope imaging with wide-field near-infrared photometry to study the neglected metal-poor Galactic globular cluster NGC 6544. A high spatial resolution map of differential reddening over the inner portion of the cluster is constructed, revealing variations of up to half of the total reddening, and the resulting corrected color-magnitude diagrams reveal a sparse blue horizontal branch and centrally concentrated blue straggler population, verified via relative proper motions. Using the corrected photometry to investigate the cluster distance, reddening, and age via direct comparison to well-calibrated photometry of clusters with similar metallicities, we estimate (m – M){sub 0}more » = 11.96, E(B – V) = 0.79, and an age coeval with M13 to within the relevant uncertainties. Although our data are insufficient to place tight constraints on the reddening law toward NGC 6544, we find no strong evidence that it is non-standard at optical or near-infrared wavelengths. We also provide near-infrared fiducial sequences extending nearly 2 mag below the cluster main sequence turnoff, generated from a statistically decontaminated sample of cluster stars. Lastly, we redetermine the cluster center and construct a radial number density profile which is well fit by an atypically flat power law with a slope of about 1.7. We discuss this result, together with a flattened main sequence luminosity function and inverted mass function, in the context of mass segregation and tidal stripping via interactions with Milky Way potential.« less
Iron and molecular opacities and the evolution of Population I stars
NASA Technical Reports Server (NTRS)
Stothers, Richard B.; Chin, Chao-Wen
1993-01-01
Effects of recent opacity revisions on the evolution of Population I stars are explored over the range 1.5-60 solar masses. Opacity parameters considered include the angular momentum coupling scheme for iron, the relative iron abundance, the total metal abundance, and diatomic and triatomic molecular sources. Only the total metal abundance exerts an important control over the evolutionary tracks. Blue loops on the H-R diagram during core helium burning can be very sensitive to opacity, but only insofar as the simple formation or suppression of a blue loop is concerned. The blue loops are most robust for stellar masses around 10 solar masses. We confirm, from a comparison of stellar models with observational data, that the total metal abundance is close to solar and that convective core overshooting is likely to be very slight. The new models predict the existence of an iron convection zone in the envelope and a great widening of the main-sequence band in the H-R diagram at luminosities brighter than 100,000 solar luminosities.
Cloning and expression of recombinant adhesive protein MEFP-2 of the blue mussel, Mytilus edulis
Silverman, Heather G.; Roberto, Francisco F.
2006-02-07
The present invention includes a Mytilus edulis cDNA having a nucleotide sequence that encodes for the Mytilus edulis foot protein-2 (Mefp-2), an example of a mollusk foot protein. Mefp-2 is an integral component of the blue mussels' adhesive protein complex, which allows the mussel to attach to objects underwater. The isolation, purification and sequencing of the Mefp-2 gene will allow researchers to produce Mefp-2 protein using genetic engineering techniques. The discovery of Mefp-2 gene sequences will also allow scientists to better understand how the blue mussel creates its waterproof adhesive protein complex.
Distéfano, Ana J; Bonacic Kresic, Ivan; Hopp, H Esteban
2010-11-01
Cotton blue disease is the most important virus disease of cotton in the southern part of America. The complete nucleotide sequence of the ssRNA genome of the cotton blue disease-associated virus was determined for the first time. It comprised 5,866 nucleotides, and the deduced genomic organization resembled that of members of the genus Polerovirus. Sequence homology comparison and phylogenetic analysis confirm that this virus (previous proposed name cotton leafroll dwarf virus) is a member of a new species within the genus Polerovirus.
The sdA problem - I. Physical properties
NASA Astrophysics Data System (ADS)
Pelisoli, Ingrid; Kepler, S. O.; Koester, D.
2018-04-01
The so-called sdA stars are defined by having H-rich spectra and surface gravities similar to hot subdwarf stars, but effective temperature below the zero-age horizontal branch. Their evolutionary history is an enigma: their surface gravity is too high for main-sequence stars, but too low for single evolution white dwarfs. They are most likely byproducts of binary evolution, including blue-stragglers, extremely-low mass white dwarf stars (ELMs) and their precursors (pre-ELMs). A small number of ELMs with similar properties to sdAs is known. Other possibilities include metal-poor A/F dwarfs, second generation stars, or even stars accreted from dwarf galaxies. In this work, we analyse colours, proper motions, and spacial velocities of a sample of sdAs from the Sloan Digital Sky Survey to assess their nature and evolutionary origin. We define a probability of belonging to the main sequence and a probability of being a (pre-)ELM based on these properties. We find that 7 per cent of the sdAs are more likely to be (pre-)ELMs than main-sequence stars. However, the spacial velocity distribution suggests that over 35 per cent of them cannot be explained as single metal-poor A/F stars.
Discovery of Extended Main-sequence Turnoffs in Four Young Massive Clusters in the Magellanic Clouds
NASA Astrophysics Data System (ADS)
Li, Chengyuan; de Grijs, Richard; Deng, Licai; Milone, Antonino P.
2017-08-01
An increasing number of young massive clusters (YMCs) in the Magellanic Clouds have been found to exhibit bimodal or extended main sequences (MSs) in their color-magnitude diagrams (CMDs). These features are usually interpreted in terms of a coeval stellar population with different stellar rotational rates, where the blue and red MS stars are populated by non- (or slowly) and rapidly rotating stellar populations, respectively. However, some studies have shown that an age spread of several million years is required to reproduce the observed wide turnoff regions in some YMCs. Here we present the ultraviolet-visual CMDs of four Large and Small Magellanic Cloud YMCs, NGC 330, NGC 1805, NGC 1818, and NGC 2164, based on high-precision Hubble Space Telescope photometry. We show that they all exhibit extended main-sequence turnoffs (MSTOs). The importance of age spreads and stellar rotation in reproducing the observations is investigated. The observed extended MSTOs cannot be explained by stellar rotation alone. Adopting an age spread of 35-50 Myr can alleviate this difficulty. We conclude that stars in these clusters are characterized by ranges in both their ages and rotation properties, but the origin of the age spread in these clusters remains unknown.
NASA Astrophysics Data System (ADS)
Combes, Francoise
2016-08-01
Considerable progress has been made on galaxy formation and evolution in recent years, and new issues. The old Hubble classification according to the tuning fork of spirals, lenticulars and ellipticals, is still useful but has given place to the red sequence, the blue cloud and the green valley, showing a real bimodality of types between star forming galaxies (blue) and quenched ones (red). Large surveys have shown that stellar mass and environment density are the two main factors of the evolution from blue to red sequences. Evolution is followed directly with redshift through a look-back time of more than 12 billion years. The most distant galaxy at z=11. has already a stellar mass of a billion suns. In an apparent anti-hierarchical scenario, the most massive galaxies form stars early on, while essentially dwarf galaxies are actively star-formers now. This downsizing feature also applies to the growth of super-massive black holes at the heart of each bulgy galaxy. The feedback from active nuclei is essential to explain the distribution of mass in galaxies, and in particular to explain why the fraction of baryonic matter is so low, lower by more than a factor 5 than the baryonic fraction of the Universe. New instruments just entering in operation, like MUSE and ALMA, provide a new and rich data flow, which is developed in this series of articles.
The Clusters AgeS Experiment (CASE). Variable Stars in the Field of the Globular Cluster M12
NASA Astrophysics Data System (ADS)
Kaluzny, J.; Thompson, I. B.; Narloch, W.; Pych, W.; Rozyczka, M.
2015-09-01
The field of the globular cluster M12 (NGC 6218) was monitored between 1995 and 2009 in a search for variable stars. BV light curves were obtained for thirty-six periodic or likely periodic variable stars. Thirty-four of these are new detections. Among the latter we identified twenty proper-motion members of the cluster: six detached or semi-detached eclipsing binaries, five contact binaries, five SX Phe pulsators, and three yellow stragglers. Two of the eclipsing binaries are located in the turnoff region, one on the lower main sequence and the remaining three among the blue stragglers. Two contact systems are blue stragglers, and the remaining three reside in the turnoff region. In the blue straggler region a total of 103 objects were found, of which 42 are proper motion members of M12, and another four are field stars. 55 of the remaining objects are located within two core radii from the center of the cluster, and as such they are likely genuine blue stragglers. We also report the discoveries of a radial color gradient of M12, and the shortest period among contact systems in globular clusters in general.
Using He I λ10830 to Diagnose Mass Flows Around Herbig Ae/Be Stars
NASA Astrophysics Data System (ADS)
Cauley, Paul W.; Johns-Krull, Christopher M.
2015-01-01
The pre-main sequence Herbig Ae/Be stars (HAEBES) are the intermediate mass cousins of the low mass T Tauri stars (TTSs). However, it is not clear that the same accretion and mass outflow mechanisms operate identically in both mass regimes. Classical TTSs (CTTSs) accrete material from their disks along stellar magnetic field lines in a scenario called magnetospheric accretion. Magnetospheric accretion requires a strong stellar dipole field in order to truncate the inner gas disk. These fields are either absent or very weak on a large majority of HAEBES, challenging the view that magnetospheric accretion is the dominant accretion mechanism. If magnetospheric accretion does not operate similarly around HAEBES as it does around CTTSs, then strong magnetocentrifugal outflows, which are directly linked to accretion and are ubiquitous around CTTSs, may be driven less efficiently from HAEBE systems. Here we present high resolution spectroscopic observations of the He I λ10830 line in a sample of 48 HAEBES. He I λ10830 is an excellent tracer of both mass infall and outflow which is directly manifested as red and blue-shifted absorption in the profile morphologies. These features, among others, are common in our sample. The occurrence of both red and blue-shifted absorption profiles is less frequent, however, than is found in CTTSs. Statistical contingency tests confirm this difference at a significant level. In addition, we find strong evidence for smaller disk truncation radii in the objects displaying red-shifted absorption profiles. This is expected for HAEBES experiencing magnetospheric accretion based on their large rotation rates and weak magnetic field strengths. Finally, the low incidence of blue-shifted absorption in our sample compared to CTTSs and the complete lack of simultaneous red and blue-shifted absorption features suggests that magnetospheric accretion in HAEBES is less efficient at driving strong outflows. The stellar wind-like outflows that are observed are likely driven, at least in part, by boundary layer accretion. The smaller (or absent) disk truncation radii in HAEBES may have consequences for the frequency of planets in close orbits around main sequence B and A stars.
Cover sequence stratigraphy and structure: Salem Church basement culmination, Georgia Blue Ridge
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, L.; Tull, J.F.
The Salem Church anticline SW of Jasper, Georgia in the western Blue Ridge is roughly an oval shaped structural dome with its long axis trending NE-SW. The anticline is cored by the Grenville age Corbin Gneiss which represents allochthonous North American basement. In debate for decades has been the age and origin of several kilometers of poly-deformed cover sequence rocks which were metamorphosed to greenschist facies and were probably transported over a long distance inland after their deposition. The stratigraphy of the cover sequence exhibits rapid lithofacies changes. At most localities, the basement is overlain by a 500--600 m thickmore » coarse clastic unit sourced from the basement rocks, composed mainly of metaconglomerate, metasandstone and metadiamictite. A thin unit less than 20 m thick of sericite phyllite occurs between the basement and the coarse clastic unit along the SE limb of the anticline but pinches out to the MW. A relatively sharp stratigraphic contact occurs between quartzite unit and overlying dark colored metagreywackes and metadiamictites containing distinctive cobbles and boulders of granitic and gneissic basement rocks up to 1 meter in length. This unit is about 100 m thick in the SW but thins rapidly towards the NE. It grades up into a geographically widespread graphitic phyllite which encircles most of the anticline. Unlike the cover sequence above the corbin basement west of Waleska, Georgia, no carbonate is found in this area.« less
Finnerty, J R; Block, B A
1992-06-01
We were able to differentiate between species of billfish (Istiophoridae family) and to detect considerable intraspecific variation in the blue marlin (Makaira nigricans) by directly sequencing a polymerase chain reaction (PCR)-amplified, 612-bp fragment of the mitochondrial cytochrome b gene. Thirteen variable nucleotide sites separated blue marlin (n = 26) into 7 genotypes. On average, these genotypes differed by 5.7 base substitutions. A smaller sample of swordfish from an equally broad geographic distribution displayed relatively little intraspecific variation, with an average of 1.3 substitutions separating different genotypes. A cladistic analysis of blue marlin cytochrome b variants indicates two major divergent evolutionary lines within the species. The frequencies of these two major evolutionary lines differ significantly between Atlantic and Pacific ocean basins. This finding is important given that the Atlantic stocks of blue marlin are considered endangered. Migration from the Pacific can help replenish the numbers of blue marlin in the Atlantic, but the loss of certain mitochondrial DNA haplotypes in the Atlantic due to overfishing probably could not be remedied by an influx of Pacific fish because of their absence in the Pacific population. Fishery management strategies should attempt to preserve the genetic diversity within the species. The detection of DNA sequence polymorphism indicates the utility of PCR technology in pelagic fishery genetics.
49 CFR 218.25 - Workers on a main track.
Code of Federal Regulations, 2012 CFR
2012-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218.25 Workers on a main track. When workers are on, under, or between rolling equipment on a main track: (a) A blue... protected includes one or more locomotives, a blue signal must be attached to the controlling locomotive at...
49 CFR 218.25 - Workers on a main track.
Code of Federal Regulations, 2010 CFR
2010-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218.25 Workers on a main track. When workers are on, under, or between rolling equipment on a main track: (a) A blue... protected includes one or more locomotives, a blue signal must be attached to the controlling locomotive at...
49 CFR 218.25 - Workers on a main track.
Code of Federal Regulations, 2011 CFR
2011-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218.25 Workers on a main track. When workers are on, under, or between rolling equipment on a main track: (a) A blue... protected includes one or more locomotives, a blue signal must be attached to the controlling locomotive at...
49 CFR 218.25 - Workers on a main track.
Code of Federal Regulations, 2013 CFR
2013-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218.25 Workers on a main track. When workers are on, under, or between rolling equipment on a main track: (a) A blue... protected includes one or more locomotives, a blue signal must be attached to the controlling locomotive at...
49 CFR 218.25 - Workers on a main track.
Code of Federal Regulations, 2014 CFR
2014-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218.25 Workers on a main track. When workers are on, under, or between rolling equipment on a main track: (a) A blue... protected includes one or more locomotives, a blue signal must be attached to the controlling locomotive at...
NASA Technical Reports Server (NTRS)
Horch, E.; Demarque, P.; Pinsonneault, M.
1992-01-01
Evolutionary calculations of high-metallicity horizontal-branch stars show that for the relevant masses and helium abundances, post-HB evolution in the HR diagram does not proceed toward and along the AGB, but rather toward a 'slow blue phase' in the vicinity of the helium-burning main sequence, following the extinction of the hydrogen shell energy source. For solar and twice solar metallicity, the blue phase begins during the helium shell-burning phase (in agreement with the work of Brocato and Castellani and Tornambe); for 3 times solar metallicity, it begins earlier, during the helium core-burning phase. This behavior differs from what takes place at lower metallicities. The implications for high-metallicity old stellar populations in the Galactic bulge and for the integrated colors of elliptical galaxies are discussed.
Large Magellanic Cloud helium-rich peculiar blue supergiants and SN 1987A
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tuchman, Y.; Wheeler, J.C.
1990-11-01
The theoretical distribution of massive stars in the H-R diagram is compared to the revised data of Fitzpatrick and Garmany for the LMC. Preferred models of about 20 M solar masses undergo a thermal contraction at T(eff) about 35,000 K at the end of core hydrogen burning but reestablish thermal equilibrium to the red of the main sequence at T(eff) about 20,000 K after ignition of a hydrogen-burning shell. They then evolve on a nuclear time scale to T(eff) about 6000 K where they lose thermal equilibrium and jump to the Hayashi track. The theoretical and observed distributions agree withmore » two significant exceptions: the blue thermal contraction gap is overpopulated compared to the theory, and there is a ledge crossing the center of the H-R diagram. The hypothesis that some of the observed stars in the blue gap are secondaries that have accreted helium-rich matter from deep within the hydrogen envelope of a red supergiant primary is explored. Some preliminary observational justification is given. 27 refs.« less
Dynamical age differences among coeval star clusters as revealed by blue stragglers.
Ferraro, F R; Lanzoni, B; Dalessandro, E; Beccari, G; Pasquato, M; Miocchi, P; Rood, R T; Sigurdsson, S; Sills, A; Vesperini, E; Mapelli, M; Contreras, R; Sanna, N; Mucciarelli, A
2012-12-20
Globular star clusters that formed at the same cosmic time may have evolved rather differently from the dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend progressively to segregate stars more massive than the average towards the cluster centre. Therefore clusters with the same chronological age may have reached quite different stages of their dynamical history (that is, they may have different 'dynamical ages'). Blue straggler stars have masses greater than those at the turn-off point on the main sequence and therefore must be the result of either a collision or a mass-transfer event. Because they are among the most massive and luminous objects in old clusters, they can be used as test particles with which to probe dynamical evolution. Here we report that globular clusters can be grouped into a few distinct families on the basis of the radial distribution of blue stragglers. This grouping corresponds well to an effective ranking of the dynamical stage reached by stellar systems, thereby permitting a direct measure of the cluster dynamical age purely from observed properties.
Discovery of Extended Main-sequence Turnoffs in Four Young Massive Clusters in the Magellanic Clouds
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Chengyuan; De Grijs, Richard; Deng, Licai
An increasing number of young massive clusters (YMCs) in the Magellanic Clouds have been found to exhibit bimodal or extended main sequences (MSs) in their color–magnitude diagrams (CMDs). These features are usually interpreted in terms of a coeval stellar population with different stellar rotational rates, where the blue and red MS stars are populated by non- (or slowly) and rapidly rotating stellar populations, respectively. However, some studies have shown that an age spread of several million years is required to reproduce the observed wide turnoff regions in some YMCs. Here we present the ultraviolet–visual CMDs of four Large and Smallmore » Magellanic Cloud YMCs, NGC 330, NGC 1805, NGC 1818, and NGC 2164, based on high-precision Hubble Space Telescope photometry. We show that they all exhibit extended main-sequence turnoffs (MSTOs). The importance of age spreads and stellar rotation in reproducing the observations is investigated. The observed extended MSTOs cannot be explained by stellar rotation alone. Adopting an age spread of 35–50 Myr can alleviate this difficulty. We conclude that stars in these clusters are characterized by ranges in both their ages and rotation properties, but the origin of the age spread in these clusters remains unknown.« less
Ogawa, Yoshio; Hirose, Dai; Akiyama, Ayano; Ichinoe, Masakatsu
2014-01-01
Penicillium roqueforti is a well known starter used for blue cheese production. Two closely related species, P. carneum and P. paneum, were previously classified as varieties of P. roqueforti. Penicillium roqueforti does not produce patulin, a mycotoxin harmful for human health, whereas both P. carneum and P. paneum actively produce this toxin. From the viewpoint of food safety, it is thus important to confirm that P. carneum and P. paneum are not used for cheese production. In the present study, the taxonomic position of Penicillium strains used for blue cheese production was examined on the basis of the partial sequence of β-tubulin. Twenty-eight Penicillium strains isolated from blue cheeses were investigated. All the examined strains belonged to P. roqueforti. Therefore, the Penicillium strains used for production of the blue cheese samples examined here do not negatively impact on human health.
A complex approach to the blue-loop problem
NASA Astrophysics Data System (ADS)
Ostrowski, Jakub; Daszynska-Daszkiewicz, Jadwiga
2015-08-01
The problem of the blue loops during the core helium burning, outstanding for almost fifty years, is one of the most difficult and poorly understood problems in stellar astrophysics. Most of the work focused on the blue loops done so far has been performed with old stellar evolution codes and with limited computational resources. In the end the obtained conclusions were based on a small sample of models and could not have taken into account more advanced effects and interactions between them.The emergence of the blue loops depends on many details of the evolution calculations, in particular on chemical composition, opacity, mixing processes etc. The non-linear interactions between these factors contribute to the statement that in most cases it is hard to predict without a precise stellar modeling whether a loop will emerge or not. The high sensitivity of the blue loops to even small changes of the internal structure of a star yields one more issue: a sensitivity to numerical problems, which are common in calculations of stellar models on advanced stages of the evolution.To tackle this problem we used a modern stellar evolution code MESA. We calculated a large grid of evolutionary tracks (about 8000 models) with masses in the range of 3.0 - 25.0 solar masses from the zero age main sequence to the depletion of helium in the core. In order to make a comparative analysis, we varied metallicity, helium abundance and different mixing parameters resulting from convective overshooting, rotation etc.The better understanding of the properties of the blue loops is crucial for our knowledge of the population of blue supergiants or pulsating variables such as Cepheids, α-Cygni or Slowly Pulsating B-type supergiants. In case of more massive models it is also of great importance for studies of the progenitors of supernovae.
The red-sequence of 72 WINGS local galaxy clusters
NASA Astrophysics Data System (ADS)
Valentinuzzi, T.; Poggianti, B. M.; Fasano, G.; D'Onofrio, M.; Moretti, A.; Ramella, M.; Biviano, A.; Fritz, J.; Varela, J.; Bettoni, D.; Vulcani, B.; Moles, M.; Couch, W. J.; Dressler, A.; Kjærgaard, P.; Omizzolo, A.; Cava, A.
2011-12-01
We study the color - magnitude red sequence and blue fraction of 72 X-ray selected galaxy clusters at z = 0.04-0.07 from the WINGS survey, searching for correlations between the characteristics of the red sequence (RS) and the environment. We consider the slope and scatter of the red sequence, the number ratio of red luminous-to-faint galaxies, the blue fraction, and the fractions of ellipticals, S0s, and spirals that compose the RS. None of these quantities correlate with the cluster velocity dispersion, X-ray luminosity, number of cluster substructures, BCG prevalence over next brightest galaxies, and the spatial concentration of ellipticals. The properties of the RS, instead, depend strongly on local galaxy density. Higher density regions have a smaller RS scatter, a higher luminous-to-faint ratio, a lower blue fraction, and a lower spiral fraction on the RS. Our results clearly illustrate the prominent effect of the local density in setting the epoch when galaxies become passive and join the red sequence, as opposed to the mass of the galaxy host structure.
Teichmann, A Lina; Nieuwenstein, Mark R; Rich, Anina N
2015-01-01
Digit-color synesthetes report experiencing colors when perceiving letters and digits. The conscious experience is typically unidirectional (e.g., digits elicit colors but not vice versa) but recent evidence shows subtle bidirectional effects. We examined whether short-term memory for colors could be affected by the order of presentation reflecting more or less structure in the associated digits. We presented a stream of colored squares and asked participants to report the colors in order. The colors matched each synesthete's colors for digits 1-9 and the order of the colors corresponded either to a sequence of numbers (e.g., [red, green, blue] if 1 = red, 2 = green, 3 = blue) or no systematic sequence. The results showed that synesthetes recalled sequential color sequences more accurately than pseudo-randomized colors, whereas no such effect was found for the non-synesthetic controls. Synesthetes did not differ from non-synesthetic controls in recall of color sequences overall, providing no evidence of a general advantage in memory for serial recall of colors.
Effects of Main-Sequence Mass Loss on Stellar and Galactic Chemical Evolution.
NASA Astrophysics Data System (ADS)
Guzik, Joyce Ann
1988-06-01
L. A. Willson, G. H. Bowen and C. Struck -Marcell have proposed that 1 to 3 solar mass stars may experience evolutionarily significant mass loss during the early part of their main-sequence phase. The suggested mass-loss mechanism is pulsation, facilitated by rapid rotation. Initial mass-loss rates may be as large as several times 10^{-9}M o/yr, diminishing over several times 10^8 years. We attempted to test this hypothesis by comparing some theoretical implications with observations. Three areas are addressed: Solar models, cluster HR diagrams, and galactic chemical evolution. Mass-losing solar models were evolved that match the Sun's luminosity and radius at its present age. The most extreme viable models have initial mass 2.0 M o, and mass-loss rates decreasing exponentially over 2-3 times 10^8 years. Compared to a constant -mass model, these models require a reduced initial ^4He abundance, have deeper envelope convection zones and higher ^8B neutrino fluxes. Early processing of present surface layers at higher interior temperatures increases the surface ^3He abundance, destroys Li, Be and B, and decreases the surface C/N ratio following first dredge-up. Evolution calculations incorporating main-sequence mass loss were completed for a grid of models with initial masses 1.25 to 2.0 Mo and mass loss timescales 0.2 to 2.0 Gyr. Cluster HR diagrams synthesized with these models confirm the potential for the hypothesis to explain observed spreads or bifurcations in the upper main sequence, blue stragglers, anomalous giants, and poor fits of main-sequence turnoffs by standard isochrones. Simple closed galactic chemical evolution models were used to test the effects of main-sequence mass loss on the F and G dwarf distribution. Stars between 3.0 M o and a metallicity -dependent lower mass are assumed to lose mass. The models produce a 30 to 60% increase in the stars to stars-plus -remnants ratio, with fewer early-F dwarfs and many more late-F dwarfs remaining on the main sequence to the present. The ratio of stars to stellar remnants and the white dwarf age distribution may prove valuable in distinguishing between explanations for the observed bimodal present-day stellar mass function.
Blue Stragglers and Other Stars of Mass Consumption in Globular Clusters
NASA Astrophysics Data System (ADS)
Panurach, Teresa; Leigh, Nathan
2018-01-01
Simulations of globular clusters suggest that collisions between main-sequence (MS) stars happen frequently. Stellar evolution models show that these collision products can be photometrically identified, appearing off the MS locus. These collision products can appear brighter and bluer than the MS turnoff, called “blue stragglers,” or even less massive and redder than the MS. We use proper motion-cleaned photometry from the Hubble Space Telescope of 38 globular clusters to identify candidate collision products. We compare the spectral energy distributions of our candidates to theoretical templates for single and multiple star systems, to constrain the possible presence of a binary companion and test consistency with theoretical stellar evolution models for collision products. For the BSs, we also compare the observed velocities from the proper motion catalog along with mass estimates derived from isochrone-fitting to theoretical predictions for both the collision and binary mass transfer models and find better agreement with the former.
A spectroscopic study of the blue stragglers in M67
NASA Astrophysics Data System (ADS)
Liu, G. Q.; Deng, L.; Chávez, M.; Bertone, E.; Davo, A. Herrero; Mata-Chávez, M. D.
2008-10-01
Based on spectrophotometric observations from the Guillermo Haro Observatory (Cananea, Mexico), a study of the spectral properties of the complete sample of 24 blue straggler stars (BSs) in the old Galactic open cluster M67 (NGC 2682) is presented. All spectra, calibrated using spectral standards, were recalibrated by means of photometric magnitudes in the Beijing-Arizona-Taipei-Connecticut system, which includes fluxes in 11 bands covering ~3500-10000 Å. The set of parameters was obtained using two complementary approaches that rely on a comparison of the spectra with (i) an empirical sample of stars with well-established spectral types and (ii) a theoretical grid of optical spectra computed at both low and high resolution. The overall results indicate that the BSs in M67 span a wide range in Teff(~ 5600 -12600 K) and surface gravities that are fully compatible with those expected for main-sequence objects (log g = 3.5 -5.0 dex).
Tan, Shuai; Wang, Zhihong; Jiang, Lichun; Peng, Rui; Zhang, Tao; Peng, Quekun; Zou, Fangdong
2017-09-01
Blue sheep, Pseudois nayaur , is endemic to the Tibetan Plateau and the surrounding mountains, which are the highest-elevation areas in the world. Classical morphological taxonomy suggests that there are two subspecies in genus Pseudois (Bovidae, Artiodactyla), namely Pseudois nayaur nayaur and Pseudois nayaur szechuanensis . However, the validity and geographic characteristics of these subspecies have never been carefully discussed and analyzed. This may be partially because previous studies have mainly focused on the vague taxonomic status of Pseudois schaeferi (dwarf blue sheep). Thus, there is an urgent need to investigate the evolutionary relationship and taxonomy system of this genus. This study enriches a previous dataset by providing a large number of new samples, based on a total of 225 samples covering almost the entire distribution of blue sheep. Molecular data from cytochrome b and the mitochondrial control region sequences were used to reconstruct the phylogeny of this species. The phylogenetic inferences show that vicariance plays an important role in diversification within this genus. In terms of molecular dating results and biogeographic analyses, the striking biogeographic pattern coincides significantly with major geophysical events. Although the results raise doubt about the present recognized distribution range of blue sheep, they have corroborated the validity of the identified subspecies in genus Pseudois . Meanwhile, these results demonstrate that the two geographically distinct populations, the Helan Mountains and Pamir Plateau populations, have been significantly differentiated from the identified subspecies, a finding that challenges the conventional taxonomy of blue sheep.
Galaxy Morphology Revealed By SDSS: Blue Elliptical Galaxies
NASA Astrophysics Data System (ADS)
Ann, Hong Bae
The Sloan Digital Sky Survey (SDSS) reveals many new features of galaxy morphologies. Among others, the discovery of blue elliptical galaxies provides some insights into the formation and evolution of galaxies. There seems to be two types of blue elliptical galaxies. One type shows globally blue colors suggesting star formations over the entire galaxy whereas the other type shows blue core that indicates enhanced star formation in the nuclear regions. The former seems to be currently forming galaxies, while the latter is thought to be in transition stage from the blue cloud to the red sequence due to AGN feedback.
Merkel, Daniel; Brinkmann, Eckard; Kämmer, Joerg C; Köhler, Miriam; Wiens, Daniel; Derwahl, Karl-Michael
2015-09-01
The electronic colorization of grayscale B-mode sonograms using various color schemes aims to enhance the adaptability and practicability of B-mode sonography in daylight conditions. The purpose of this study was to determine the diagnostic effectiveness and importance of colorized B-mode sonography. Fifty-three video sequences of sonographic examinations of the liver were digitized and subsequently colorized in 2 different color combinations (yellow-brown and blue-white). The set of 53 images consisted of 33 with isoechoic masses, 8 with obvious lesions of the liver (hypoechoic or hyperechoic), and 12 with inconspicuous reference images of the liver. The video sequences were combined in a random order and edited into half-hour video clips. Isoechoic liver lesions were successfully detected in 58% of the yellow-brown video sequences and in 57% of the grayscale video sequences (P = .74, not significant). Fifty percent of the isoechoic liver lesions were successfully detected in the blue-white video sequences, as opposed to a 55% detection rate in the corresponding grayscale video sequences (P= .11, not significant). In 2 subgroups, significantly more liver lesions were detected with grayscale sonography compared to blue-white sonography. Yellow-brown-colorized B-mode sonography appears to be similarly effective for detection of isoechoic parenchymal liver lesions as traditional grayscale sonography. Blue-white colorization in B-mode sonography is probably not as effective as grayscale sonography, although a statistically significant disadvantage was shown only in the subgroup of hyperechoic liver lesions. © 2015 by the American Institute of Ultrasound in Medicine.
49 CFR 218.27 - Workers on track other than main track.
Code of Federal Regulations, 2010 CFR
2010-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218... on track other than main track— (a) A blue signal must be displayed at or near each manually operated... blue signal protection as provided for in this section is on a track equipped with one or more...
49 CFR 218.27 - Workers on track other than main track.
Code of Federal Regulations, 2013 CFR
2013-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218... on track other than main track— (a) A blue signal must be displayed at or near each manually operated... blue signal protection as provided for in this section is on a track equipped with one or more...
49 CFR 218.27 - Workers on track other than main track.
Code of Federal Regulations, 2011 CFR
2011-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218... on track other than main track— (a) A blue signal must be displayed at or near each manually operated... blue signal protection as provided for in this section is on a track equipped with one or more...
49 CFR 218.27 - Workers on track other than main track.
Code of Federal Regulations, 2014 CFR
2014-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218... on track other than main track— (a) A blue signal must be displayed at or near each manually operated... blue signal protection as provided for in this section is on a track equipped with one or more...
49 CFR 218.27 - Workers on track other than main track.
Code of Federal Regulations, 2012 CFR
2012-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Blue Signal Protection of Workers § 218... on track other than main track— (a) A blue signal must be displayed at or near each manually operated... blue signal protection as provided for in this section is on a track equipped with one or more...
Rapidly rotating second-generation progenitors for the 'blue hook' stars of ω Centauri.
Tailo, Marco; D'Antona, Francesca; Vesperini, Enrico; Di Criscienzo, Marcella; Ventura, Paolo; Milone, Antonino P; Bellini, Andrea; Dotter, Aaron; Decressin, Thibaut; D'Ercole, Annibale; Caloi, Vittoria; Capuzzo-Dolcetta, Roberto
2015-07-16
Horizontal branch stars belong to an advanced stage in the evolution of the oldest stellar galactic population, occurring either as field halo stars or grouped in globular clusters. The discovery of multiple populations in clusters that were previously believed to have single populations gave rise to the currently accepted theory that the hottest horizontal branch members (the 'blue hook' stars, which had late helium-core flash ignition, followed by deep mixing) are the progeny of a helium-rich 'second generation' of stars. It is not known why such a supposedly rare event (a late flash followed by mixing) is so common that the blue hook of ω Centauri contains approximately 30 per cent of the horizontal branch stars in the cluster, or why the blue hook luminosity range in this massive cluster cannot be reproduced by models. Here we report that the presence of helium core masses up to about 0.04 solar masses larger than the core mass resulting from evolution is required to solve the luminosity range problem. We model this by taking into account the dispersion in rotation rates achieved by the progenitors, whose pre-main-sequence accretion disk suffered an early disruption in the dense environment of the cluster's central regions, where second-generation stars form. Rotation may also account for frequent late-flash-mixing events in massive globular clusters.
Cannibals in the thick disk: the young α-rich stars as evolved blue stragglers
NASA Astrophysics Data System (ADS)
Jofré, P.; Jorissen, A.; Van Eck, S.; Izzard, R. G.; Masseron, T.; Hawkins, K.; Gilmore, G.; Paladini, C.; Escorza, A.; Blanco-Cuaresma, S.; Manick, R.
2016-10-01
Spectro-seismic measurements of red giants enabled the recent discovery of stars in the thick disk that are more massive than 1.4 M⊙. While it has been claimed that most of these stars are younger than the rest of the typical thick disk stars, we show evidence that they might be products of mass transfer in binary evolution, notably evolved blue stragglers. We took new measurements of the radial velocities in a sample of 26 stars from APOKASC, including 13 "young" stars and 13 "old" stars with similar stellar parameters but with masses below 1.2 M⊙ and found that more of the young starsappear to be in binary systems with respect to the old stars.Furthermore, we show that the young stars do not follow the expected trend of [C/H] ratios versus mass for individual stars. However, with a population synthesis of low-mass stars including binary evolution and mass transfer, we can reproduce the observed [C/N] ratios versus mass. Our study shows how asteroseismology of solar-type red giants provides us with a unique opportunity to study the evolution of field blue stragglers after they have left the main-sequence.
Shen, Dong-Dong; Wang, Ji-Fei; Zhang, Dan-Yu; Peng, Zhi-Wei; Yang, Tian-Yun; Wang, Zhao-Ding; Bowman, Dwight D; Hou, Zhi-Jun; Liu, Zhen-Sheng
2017-09-19
Haemonchus contortus is known among parasitic nematodes as one of the major veterinary pathogens of small ruminants and results in great economic losses worldwide. Human activities, such as the sympatric grazing of wild with domestic animals, may place susceptible wildlife hosts at risk of increased prevalence and infection intensity with this common small ruminant parasite. Studies on phylogenetic factors of H. contortus should assist in defining the amount of the impact of anthropogenic factors on the extent of sharing of agents such as this nematode between domestic animals and wildlife. H. contortus specimens (n = 57) were isolated from wild blue sheep (Pseudois nayaur) inhabiting Helan Mountains (HM), China and additional H. contortus specimens (n = 20) were isolated from domestic sheep that were grazed near the natural habitat of the blue sheep. Complete ITS2 (second internal transcribed spacer) sequences and partial sequences of the nad4 (nicotinamide dehydrogenase subunit 4 gene) gene were amplified to determine the sequence variations and population genetic diversities between these two populations. Also, 142 nad4 haplotype sequences of H. contortus from seven other geographical regions of China were retrieved from database to further examine the H. contortus population structure. Sequence analysis revealed 10 genotypes (ITS2) and 73 haplotypes (nad4) among the 77 specimens, with nucleotide diversities of 0.007 and 0.021, respectively, similar to previous studies in other countries, such as Pakistan, Malaysia and Yemen. Phylogenetic analyses (BI, MP, NJ) of nad4 sequences showed that there were no noticeable boundaries among H. contortus populations from different geographical origin and population genetic analyses revealed that most of the variation (94.21%) occurred within H. contortus populations. All phylogenetic analyses indicated that there was little genetic differentiation but a high degree of gene flow among the H. contortus populations among wild blue sheep and domestic ruminants in China. The current work is the first genetic characterization of H. contortus isolated from wild blue sheep in the Helan Mountains region. The results revealed a low genetic differentiation and high degree of gene flow between the H. contortus populations from sympatric wild blue sheep and domestic sheep, indicating regular cross-infection between the sympatrically reared ruminants.
NASA Astrophysics Data System (ADS)
Li, Chengyuan; Deng, Licai; de Grijs, Richard; Jiang, Dengkai; Xin, Yu
2018-03-01
The bifurcated patterns in the color–magnitude diagrams of blue straggler stars (BSSs) have attracted significant attention. This type of special (but rare) pattern of two distinct blue straggler sequences is commonly interpreted as evidence that cluster core-collapse-driven stellar collisions are an efficient formation mechanism. Here, we report the detection of a bifurcated blue straggler distribution in a young Large Magellanic Cloud cluster, NGC 2173. Because of the cluster’s low central stellar number density and its young age, dynamical analysis shows that stellar collisions alone cannot explain the observed BSSs. Therefore, binary evolution is instead the most viable explanation of the origin of these BSSs. However, the reason why binary evolution would render the color–magnitude distribution of BSSs bifurcated remains unclear. C. Li, L. Deng, and R. de Grijs jointly designed this project.
Proteomics meets blue biotechnology: a wealth of novelties and opportunities.
Hartmann, Erica M; Durighello, Emie; Pible, Olivier; Nogales, Balbina; Beltrametti, Fabrizio; Bosch, Rafael; Christie-Oleza, Joseph A; Armengaud, Jean
2014-10-01
Blue biotechnology, in which aquatic environments provide the inspiration for various products such as food additives, aquaculture, biosensors, green chemistry, bioenergy, and pharmaceuticals, holds enormous promise. Large-scale efforts to sequence aquatic genomes and metagenomes, as well as campaigns to isolate new organisms and culture-based screenings, are helping to push the boundaries of known organisms. Mass spectrometry-based proteomics can complement 16S gene sequencing in the effort to discover new organisms of potential relevance to blue biotechnology by facilitating the rapid screening of microbial isolates and by providing in depth profiles of the proteomes and metaproteomes of marine organisms, both model cultivable isolates and, more recently, exotic non-cultivable species and communities. Proteomics has already contributed to blue biotechnology by identifying aquatic proteins with potential applications to food fermentation, the textile industry, and biomedical drug development. In this review, we discuss historical developments in blue biotechnology, the current limitations to the known marine biosphere, and the ways in which mass spectrometry can expand that knowledge. We further speculate about directions that research in blue biotechnology will take given current and near-future technological advancements in mass spectrometry. Copyright © 2014 Elsevier B.V. All rights reserved.
MHC class II B diversity in blue tits: a preliminary study.
Aguilar, Juan Rivero-de; Schut, Elske; Merino, Santiago; Martínez, Javier; Komdeur, Jan; Westerdahl, Helena
2013-07-01
In this study, we partly characterize major histocompatibility complex (MHC) class II B in the blue tit (Cyanistes caeruleus). A total of 22 individuals from three different European locations: Spain, The Netherlands, and Sweden were screened for MHC allelic diversity. The MHC genes were investigated using both PCR-based methods and unamplified genomic DNA with restriction fragment length polymorphism (RFLP) and southern blots. A total of 13 different exon 2 sequences were obtained independently from DNA and/or RNA, thus confirming gene transcription and likely functionality of the genes. Nine out of 13 alleles were found in more than one country, and two alleles appeared in all countries. Positive selection was detected in the region coding for the peptide binding region (PBR). A maximum of three alleles per individual was detected by sequencing and the RFLP pattern consisted of 4-7 fragments, indicating a minimum number of 2-4 loci per individual. A phylogenetic analysis, demonstrated that the blue tit sequences are divergent compared to sequences from other passerines resembling a different MHC lineage than those possessed by most passerines studied to date.
MHC class II B diversity in blue tits: a preliminary study
Aguilar, Juan Rivero-de; Schut, Elske; Merino, Santiago; Martínez, Javier; Komdeur, Jan; Westerdahl, Helena
2013-01-01
In this study, we partly characterize major histocompatibility complex (MHC) class II B in the blue tit (Cyanistes caeruleus). A total of 22 individuals from three different European locations: Spain, The Netherlands, and Sweden were screened for MHC allelic diversity. The MHC genes were investigated using both PCR-based methods and unamplified genomic DNA with restriction fragment length polymorphism (RFLP) and southern blots. A total of 13 different exon 2 sequences were obtained independently from DNA and/or RNA, thus confirming gene transcription and likely functionality of the genes. Nine out of 13 alleles were found in more than one country, and two alleles appeared in all countries. Positive selection was detected in the region coding for the peptide binding region (PBR). A maximum of three alleles per individual was detected by sequencing and the RFLP pattern consisted of 4–7 fragments, indicating a minimum number of 2–4 loci per individual. A phylogenetic analysis, demonstrated that the blue tit sequences are divergent compared to sequences from other passerines resembling a different MHC lineage than those possessed by most passerines studied to date. PMID:23919136
Strandh, Maria; Lannefors, Mimi; Bonadonna, Francesco; Westerdahl, Helena
2011-10-01
The great polymorphism observed in the major histocompatibility complex (MHC) genes is thought to be maintained by pathogen-mediated selection possibly combined with MHC-disassortative mating, guided by MHC-determined olfactory cues. Here, we partly characterize the MHC class I and II B of the blue petrel, Halobaena caerulea (Procellariiformes), a bird with significant olfactory abilities that lives under presumably low pathogen burdens in Subantarctica. Blue petrels are long-lived, monogamous birds which suggest the necessity of an accurate mate choice process. The species is ancestral to songbirds (Passeriformes; many MHC loci), although not to gamefowls (Galliformes; few MHC loci). Considering the phylogenetic relationships and the low subantarctic pathogen burden, we expected few rather than many MHC loci in the blue petrel. However, when we analysed partial MHC class I and class II B cDNA and gDNA sequences we found evidence for as many as at least eight MHC class I loci and at least two class II B loci. These class I and II B sequences showed classical MHC characteristics, e.g. high nucleotide diversity, especially in putative peptide-binding regions where signatures of positive selection was detected. Trans-species polymorphism was found between MHC class II B sequences of the blue petrel and those of thin-billed prion, Pachyptila belcheri, two species that diverged ∼25 MYA. The observed MHC allele richness in the blue petrel may well serve as a basis for mate choice, especially since olfactory discrimination of MHC types may be possible in this species.
Yan, S Q; Hou, J N; Bai, C Y; Jiang, Y; Zhang, X J; Ren, H L; Sun, B X; Zhao, Z H; Sun, J H
2014-04-01
The dominant white coat colour of farmed blue fox is inherited as a monogenic autosomal dominant trait and is suggested to be embryonic lethal in the homozygous state. In this study, the transcripts of KIT were identified by RT-PCR for a dominant white fox and a normal blue fox. Sequence analysis showed that the KIT transcript in normal blue fox contained the full-length coding sequence of 2919 bp (GenBank Acc. No KF530833), but in the dominant white individual, a truncated isoform lacking the entire exon 12 specifically co-expressed with the normal transcript. Genomic DNA sequencing revealed that a single nucleotide polymorphism (c.1867+1G>T) in intron 12 appeared only in the dominant white individuals and a 1-bp ins/del polymorphism in the same intron showed in individuals representing two different coat colours. Genotyping results of the SNP with PCR-RFLP in 185 individuals showed all 90 normal blue foxes were homozygous for the G allele, and all dominant white individuals were heterozygous. Due to the truncated protein with a deletion of 35 amino acids and an amino acid replacement (p.Pro623Ala) located in the conserved ATP binding domain, we propose that the mutant receptor had absent tyrosine kinase activity. These findings reveal that the base substitution at the first nucleotide of intron 12 of KIT gene, resulting in skipping of exon 12, is a causative mutation responsible for the dominant white phenotype of blue fox. © 2013 Stichting International Foundation for Animal Genetics.
Xu, Xinran; Chen, Xiangdong; Yu, Wumengxiao; Liu, Yu; Zhang, Weiwei; Lan, Jin
2017-08-01
Blue light plays an important role during the growth of Ganoderma lucidum, one of the best-known medicinal macrofungi in China. In the present study, we cloned Glwc-1 and Glwc-2, the homologue of the blue light photoreceptors Ncwc-1 and Ncwc-2 of Neurospora crassa, from G. lucidum. The deduced amino acid sequence of Glwc-1 contained the similar function domains as NcWC-1 including LOV, PAS B, PAS C, and PAC domains. The deduced amino acid sequence of Glwc-2 contained PAS domain and GATA-type zinc finger (Znf) domain as well as NcWC-2. Phylogenetic analysis based on fungal WC-1 and WC-2 supported GlWC-1 and GlWC-2 were blue light receptors. The expression of Glwc-1 and Glwc-2 indicated that they might play an important role during the primordium differentiation process of G. lucidum, and the external blue light stimulation increased the expression of Glwc-1 and Glwc-2. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Ramey, Andy M.; Reeves, Andrew; Poulson, Rebecca L.; Carter, Deborah L.; Davis-Fields, Nicholas; Stallknecht, David E.
2016-01-01
We report here the complete genome sequence of a novel H14N7 subtype influenza A virus (IAV) isolated from a blue-winged teal (Anas discors) harvested in Texas, USA. The genomic characteristics of this IAV strain with a previously undetected subtype combination suggest recent viral evolution within the New World wild-bird IAV reservoir.
2010-05-22
member B8 Blue 1370939_at Acsl1 acyl-CoA synthetase long-chain family member 1 Yellow 1372006_at --- --- Blue 1372101_at Ppap2b phosphatidic acid ...Stress L-ascorbic Acid Binding Cation Binding Identical Protein Binding Protein Dimerization Activity Dioxygenase Activity Oxidoreductase...Reference Sequence (RefSeq): a curated non-redundant sequence database of genomes, transcripts, and proteins. Nucleic Acid Research. 35: D61-65. Ryter SW
Sequences show rapid motor transfer and spatial translation in the oculomotor system.
Stainer, Matthew J; Carpenter, R H S; Brotchie, Peter; Anderson, Andrew J
2016-07-01
Every day we perform learnt sequences of actions that seem to happen almost without awareness. It has been argued that for learning such sequences parallel learning networks exist - one using spatial coordinates and one using motor coordinates - with sequence acquisition involving a progressive shift from the former to the latter as a sequence is rehearsed. When sequences are interrupted by an out-of-sequence target, there is a delay in the response to the target, and so here we transiently interrupt oculomotor sequences to probe the influence of oculomotor rehearsal and spatial coordinates in sequence acquisition. For our main experiments, we used a repeating sequences of eight targets in length that was first learnt either using saccadic eye movements (left/right), manual responses (left/right or up/down) or as a sequence of colour (blue/red) requiring no motor response. The sequence was immediately repeated for saccadic eye movements, during which the influence of on out-of-sequence target (an interruption) was assessed. When a sequence is learnt beforehand in an abstract way (for example, as a sequence of colours or of orthogonally mapped manual responses), interruptions are immediately disruptive to latency, suggesting neither motor rehearsal nor specific spatial coordinates are essential for encoding sequences of actions and that sequences - no matter how they are encoded - can be rapidly translated into oculomotor coordinates. The magnitude of a disruption does, however, correspond to how well a sequence is learnt: introducing an interruption to an extended sequence before it was reliably learnt reduces the magnitude of the latency disruption. Copyright © 2016 Elsevier Ltd. All rights reserved.
Viviani, Vadim R; Amaral, Danilo; Prado, Rogilene; Arnoldi, Frederico G C
2011-12-01
Firefly luciferases usually produce bioluminescence in the yellow-green region, with colors in the green and yellow-orange extremes of the spectrum being less common. Several firefly luciferases have already been cloned and sequenced, and site-directed mutagenesis studies have already identified important regions and residues for bioluminescence colors. However the structural determinants and mechanisms of bioluminescence colors turned out to be elusive, mainly when comparing luciferases with a high degree of divergence. Thus comparison of more similar luciferases producing colors in the two extremes of the spectrum could be revealing. The South-American fauna of fireflies remains largely unstudied, with some unique taxa that are not found anywhere else in the world and that produce a wide range of bioluminescence colors. Among them, fireflies of the genus Amydetes are especially interesting because its taxonomical status as an independent subfamily or as a tribe is not yet solved, and because they usually produce a continuous bright blue-shifted bioluminescence. In this work we cloned the cDNA for the luciferase of the Atlantic rain forest Amydetes fanestratus firefly, which is found near Sorocaba municipality (São Paulo, Brazil). Despite showing a higher degree of identity with the South-American Cratomorphus, the European Lampyris and the Asiatic Pyrocoelia, phylogenetical analysis of the luciferase sequence support the inclusion of Amydetes as an independent subfamily. Amydetes luciferase displays one of the most blue-shifted emission spectra (λ(max) = 538 nm) among beetle luciferases, with lower pH-sensitivity and higher affinity for ATP when compared to other luciferases, making this luciferase attractive for sensitive ATP and reporter assays.
A stellar audit: the computation of encounter rates for 47 Tucanae and omega Centauri
NASA Astrophysics Data System (ADS)
Davies, Melvyn B.; Benz, Willy
1995-10-01
Using King-Mitchie models, we compute encounter rates between the various stellar species in the globular clusters omega Cen and 47 Tuc. We also compute event rates for encounters between single stars and a population of primordial binaries. Using these rates, and what we have learnt from hydrodynamical simulations of encounters performed earlier, we compute the production rates of objects such as low-mass X-ray binaries (LMXBs), smothered neutron stars and blue stragglers (massive main-sequence stars). If 10 per cent of the stars are contained in primordial binaries, the production rate of interesting objects from encounters involving these binaries is as large as that from encounters between single stars. For example, encounters involving binaries produce a significant number of blue stragglers in both globular cluster models. The number of smothered neutron stars may exceed the number of LMXBs by a factor of 5-20, which may help to explain why millisecond pulsars are observed to outnumber LMXBs in globular clusters.
Two distinct sequences of blue straggler stars in the globular cluster M 30.
Ferraro, F R; Beccari, G; Dalessandro, E; Lanzoni, B; Sills, A; Rood, R T; Pecci, F Fusi; Karakas, A I; Miocchi, P; Bovinelli, S
2009-12-24
Stars in globular clusters are generally believed to have all formed at the same time, early in the Galaxy's history. 'Blue stragglers' are stars massive enough that they should have evolved into white dwarfs long ago. Two possible mechanisms have been proposed for their formation: mass transfer between binary companions and stellar mergers resulting from direct collisions between two stars. Recently the binary explanation was claimed to be dominant. Here we report that there are two distinct parallel sequences of blue stragglers in M 30. This globular cluster is thought to have undergone 'core collapse', during which both the collision rate and the mass transfer activity in binary systems would have been enhanced. We suggest that the two observed sequences are a consequence of cluster core collapse, with the bluer population arising from direct stellar collisions and the redder one arising from the evolution of close binaries that are probably still experiencing an active phase of mass transfer.
ERIC Educational Resources Information Center
Anderson, Laurens; Wittkopp, Stacy M.; Painter, Christopher J.; Liegel, Jessica J.; Schreiner, Rodney; Bell, Jerry A.; Shakhashiri, Bassam Z.
2012-01-01
An investigation of the Blue Bottle Experiment, a well-known lecture demonstration reaction involving the dye-catalyzed air oxidation of a reducing sugar in alkaline solution, has delineated the sequence of reactions leading to the bleaching of the dye, the regeneration of color, and so forth. Enolization of the sugar is proposed as a key step in…
IMPLICATIONS FOR THE FORMATION OF BLUE STRAGGLER STARS FROM HST ULTRAVIOLET OBSERVATIONS OF NGC 188
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gosnell, Natalie M.; Mathieu, Robert D.; Geller, Aaron M.
We present results of a Hubble Space Telescope (HST) far-ultraviolet (FUV) survey searching for white dwarf (WD) companions to blue straggler stars (BSSs) in open cluster NGC 188. The majority of NGC 188 BSSs (15 of 21) are single-lined binaries with properties suggestive of mass-transfer formation via Roche lobe overflow, specifically through an asymptotic giant branch star transferring mass to a main sequence secondary, yielding a BSS binary with a WD companion. In NGC 188, a BSS formed by this mechanism within the past 400 Myr will have a WD companion that is hot and luminous enough to be directlymore » detected as a FUV photometric excess with HST. Comparing expected BSS FUV emission to observed photometry reveals four BSSs with WD companions above 12,000 K (younger than 250 Myr) and three WD companions with temperatures between 11,000 and 12,000 K. These BSS+WD binaries all formed through recent mass transfer. The location of the young BSSs in an optical color–magnitude diagram (CMD) indicates that distance from the zero-age main sequence does not necessarily correlate with BSS age. There is no clear CMD separation between mass transfer-formed BSSs and those likely formed through other mechanisms, such as collisions. The seven detected WD companions place a lower limit on the mass-transfer formation frequency of 33%. We consider other possible formation mechanisms by comparing properties of the BSS population to theoretical predictions. We conclude that 14 BSS binaries likely formed from mass transfer, resulting in an inferred mass-transfer formation frequency of approximately 67%.« less
THE BLUE TIP OF THE STELLAR LOCUS: MEASURING REDDENING WITH THE SLOAN DIGITAL SKY SURVEY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schlafly, Edward F.; Finkbeiner, Douglas P.; Juric, Mario
2010-12-10
We present measurements of reddening due to dust using the colors of stars in the Sloan Digital Sky Survey (SDSS). We measure the color of main-sequence turnoff stars by finding the 'blue tip' of the stellar locus: the prominent blue edge in the distribution of stellar colors. The method is sensitive to color changes of order 18, 12, 7, and 8 mmag of reddening in the colors u - g, g - r, r - i, and i - z, respectively, in regions measuring 90' by 14'. We present maps of the blue tip colors in each of these bandsmore » over the entire SDSS footprint, including the new dusty southern Galactic cap data provided by the SDSS-III. The results disfavor the best-fit O'Donnell and Cardelli et al. reddening laws, but are described well by a Fitzpatrick reddening law with R{sub V} = 3.1. The Schlegel et al. (SFD) dust map is found to trace the dust well, but overestimates reddening by factors of 1.4, 1.0, 1.2, and 1.4 in u - g, g - r, r - i, and i - z largely due to the adopted reddening law. In select dusty regions of the sky, we find evidence for problems in the SFD temperature correction. A dust map normalization difference of 15% between the Galactic north and south sky may be due to these dust temperature errors.« less
Evidence of the evolved nature of the B[e] star MWC 137
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muratore, M. F.; Arias, M. L.; Cidale, L.
2015-01-01
The evolutionary phase of B[e] stars is difficult to establish due to the uncertainties in their fundamental parameters. For instance, possible classifications for the Galactic B[e] star MWC 137 include pre-main-sequence and post-main-sequence phases, with a large range in luminosity. Our goal is to clarify the evolutionary stage of this peculiar object, and to study the CO molecular component of its circumstellar medium. To this purpose, we modeled the CO molecular bands using high-resolution K-band spectra. We find that MWC 137 is surrounded by a detached cool (T=1900±100 K) and dense (N=(3±1)×10{sup 21} cm{sup −2}) ring of CO gas orbitingmore » the star with a rotational velocity, projected to the line of sight, of 84 ± 2 km s{sup −1}. We also find that the molecular gas is enriched in the isotope {sup 13}C, excluding the classification of the star as a Herbig Be. The observed isotopic abundance ratio ({sup 12}C/{sup 13}C = 25 ± 2) derived from our modeling is compatible with a proto-planetary nebula, main-sequence, or supergiant evolutionary phase. However, based on some observable characteristics of MWC 137, we propose that the supergiant scenario seems to be the most plausible. Hence, we suggest that MWC 137 could be in an extremely short-lived phase, evolving from a B[e] supergiant to a blue supergiant with a bipolar ring nebula.« less
The Clusters AgeS Experiment (CASE). Variable Stars in the Field of the Globular Cluster NGC 3201
NASA Astrophysics Data System (ADS)
Kaluzny, J.; Rozyczka, M.; Thompson, I. B.; Narloch, W.; Mazur, B.; Pych, W.; Schwarzenberg-Czerny, A.
2016-01-01
The field of the globular cluster NGC 3201 was monitored between 1998 and 2009 in a search for variable stars. BV light curves were obtained for 152 periodic or likely periodic variables, fifty-seven of which are new detections. Thirty-seven newly detected variables are proper motion members of the cluster. Among them we found seven detached or semi-detached eclipsing binaries, four contact binaries, and eight SX Phe pulsators. Four of the eclipsing binaries are located in the turnoff region, one on the lower main sequence and the remaining two slightly above the subgiant branch. Two contact systems are blue stragglers, and another two reside in the turnoff region. In the blue straggler region a total of 266 objects were found, of which 140 are proper motion (PM) members of NGC 3201, and another nineteen are field stars. Seventy-eight of the remaining objects for which we do not have PM data are located within the half-light radius from the center of the cluster, and most of them are likely genuine blue stragglers. Four variable objects in our field of view were found to coincide with X-ray sources: three chromospherically active stars and a quasar at a redshift z≍0.5.
NASA Technical Reports Server (NTRS)
Stothers, Richard B.; Hansen, James E. (Technical Monitor)
2002-01-01
Theoretical models of the remnants of massive stars in a very hot, post-red-supergiant phase display no obvious instability if standard assumptions are made. However, the brightest observed classical luminous blue variables (LBVs) may well belong to such a phase. A simple time-dependent theory of moving stellar envelopes is developed in order to treat deep hydrodynamical disturbances caused by surface mass loss and to test the moving envelopes for dynamical instability. In the case of steady-state outflow, the theory reduces to the equivalent of the Castor, Abbott, and Klein formulation for optically thick winds at distances well above the sonic point. The time-dependent version indicates that the brightest and hottest LBVs are both dynamically and radiatively unstable, as a result of the substantial lowering of the generalized Eddington luminosity limit by the mass-loss acceleration. It is suggested that dynamical instability, by triggering secular cycles of mass loss, is primarily what differentiates LBVs from the purely radiatively unstable Wolf-Rayet stars. Furthermore, when accurate main-sequence mass-loss rates are used to calculate the evolutionary tracks, the predicted surface hydrogen and nitrogen abundances of the blue remnants agree much better with observations of the brightest LBVs than before.
Leknes, I L
2015-10-01
The structure and histochemical properties of the intestine in bronze corydoras (Corydoras aeneus), a stomach-containing teleost, are described, with emphasis on goblet cells and mucin types. The proximal intestine displayed a normal structure for teleosts, whereas the distal intestine was wide, translucent, thin-walled, richly vascularized and constantly filled with air, suggesting an important respiratory role. Goblet cells were common throughout the entire intestine and displayed a variable, but mainly faint metachromatic colour after toluidine blue. They were moderately coloured by alcian blue at both pH 2.5 and 0.2 and displayed no colour after periodic acid followed by Schiff's solution (PAS), but a distinct purple-brown colour after high iron diamine followed by alcian blue (pH 2.5). Together, these results suggest that the mucin in the intestine goblet cells consists mainly of sulphated proteoglycans. Further, the results from the present lectin and neuraminidase tests suggest that these mucins contain much N-acetylglucoseamines and some N-acetylgalactosamines and sialic acid, but seem to lack glucose and mannose. They also contain some galactose-N-acetylgalactosamines sequences, normally hidden by sialic acid. The distinct brush border and mucus layer on the epithelial cells in the respiratory intestine may indicate some digestive roles, such as absorption of water, ions and simple carbohydrates. As sulphated proteoglycans are tough and attract much water, this mucus may play important roles in the protection against mechanical and chemical damages and in the defence against micro-organisms throughout the entire intestine, but in the respiratory intestine it may impede significantly the oxygen uptake. However, as this part of the intestine usually contains no digesta, but is completely filled with air, frequently renewed by dry air from the atmosphere, and the main function of the mucus may be to protect the respiratory epithelium against a destroying and dangerous desiccation. © 2014 Blackwell Verlag GmbH.
Liao, R; Zhang, X; Chen, Q; Wang, Z; Wang, Q; Yang, C; Pan, Y
2016-10-01
This study was designed to investigate the genetic basis of growth and egg traits in Dongxiang blue-shelled chickens and White Leghorn chickens. In this study, we employed a reduced representation sequencing approach called genotyping by genome reducing and sequencing to detect genome-wide SNPs in 252 Dongxiang blue-shelled chickens and 252 White Leghorn chickens. The Dongxiang blue-shelled chicken breed has many specific traits and is characterized by blue-shelled eggs, black plumage, black skin, black bone and black organs. The White Leghorn chicken is an egg-type breed with high productivity. As multibreed genome-wide association studies (GWASs) can improve precision due to less linkage disequilibrium across breeds, a multibreed GWAS was performed with 156 575 SNPs to identify the associated variants underlying growth and egg traits within the two chicken breeds. The analysis revealed 32 SNPs exhibiting a significant genome-wide association with growth and egg traits. Some of the significant SNPs are located in genes that are known to impact growth and egg traits, but nearly half of the significant SNPs are located in genes with unclear functions in chickens. To our knowledge, this is the first multibreed genome-wide report for the genetics of growth and egg traits in the Dongxiang blue-shelled and White Leghorn chickens. © 2016 Stichting International Foundation for Animal Genetics.
Abraham Lincoln's blue pills. Did our 16th president suffer from mercury poisoning?
Hirschhorn, N; Feldman, R G; Greaves, I A
2001-01-01
It is well known that Abraham Lincoln took a medicine called "blue mass" or "blue pill," commonly prescribed in the 19th century. What is now hardly known is that the main ingredient of blue mass was finely dispersed elemental mercury. As his friends understood, mercury was often prescribed for melancholy or "hypochondriasis," a condition Lincoln famously endured. Mercury in the form of the blue pill is a potential neurotoxin, which we have demonstrated by recreating and testing the recipe. We present the testimony of many of Lincoln's contemporaries to suggest that Lincoln suffered the neurobehavioural consequences of mercury intoxication but, perhaps crucial to history, before the main years of his presidency; he was astute enough to recognize the effects and stop the medication soon after his inauguration.
Hamidi-Asl, Ezat; Raoof, Jahan Bakhsh; Naghizadeh, Nahid; Akhavan-Niaki, Haleh; Ojani, Reza; Banihashemi, Ali
2016-10-01
The main roles of DNA in the cells are to maintain and properly express genetic information. It is important to have analytical methods capable of fast and sensitive detection of DNA damage. DNA hybridization sensors are well suited for diagnostics and other purposes, including determination of bacteria and viruses. Beta thalassemias (βth) are due to mutations in the β-globin gene. In this study, an electrochemical biosensor which detects the sequences related to the β-globin gene issued from real samples amplified by polymerase chain reaction (PCR) is described for the first time. The biosensor relies on the immobilization of 20-mer single stranded oligonucleotide (probe) related to βth sequence on the carbon paste electrode (CPE) modified by 15% silver (Ag) and platinum (Pt) nanoparticles to prepare the bimetallic nanocomposite electrode and hybridization of this oligonucleotide with its complementary sequence (target). The extent of hybridization between the probe and target sequences was shown by using linear sweep voltammetry (LSV) with methylene blue (MB) as hybridization indicator. The selectivity of sensor was investigated using PCR samples containing non-complementary oligonucleotides. The detection limit of biosensor was calculated about 470.0pg/μL. Copyright © 2016 Elsevier B.V. All rights reserved.
Comparing the white dwarf cooling sequences in 47 Tuc and NGC 6397
DOE Office of Scientific and Technical Information (OSTI.GOV)
Richer, Harvey B.; Goldsbury, Ryan; Heyl, Jeremy
2013-12-01
Using deep Hubble Space Telescope imaging, color-magnitude diagrams are constructed for the globular clusters 47 Tuc and NGC 6397. As expected, because of its lower metal abundance, the main sequence of NGC 6397 lies well to the blue of that of 47 Tuc. A comparison of the white dwarf cooling sequences of the two clusters, however, demonstrates that these sequences are indistinguishable over most of their loci—a consequence of the settling out of heavy elements in the dense white dwarf atmosphere and the near equality of their masses. Lower quality data on M4 continues this trend to a third clustermore » whose metallicity is intermediate between these two. While the path of the white dwarfs in the color-magnitude diagram is nearly identical in 47 Tuc and NGC 6397, the numbers of white dwarfs along the path are not. This results from the relatively rapid relaxation in NGC 6397 compared to 47 Tuc and provides a cautionary note that simply counting objects in star clusters in random locations as a method of testing stellar evolutionary theory is likely dangerous unless dynamical considerations are included.« less
USDA-ARS?s Scientific Manuscript database
Blue mold caused by Penicillium expansum is the most important postharvest disease of apple worldwide and results in significant financial losses. There are no defined sources of resistance to blue mold in domesticated apple; however, resistance has been described in wild Malus sieversii accessions...
Genome sequence of Penicillium solitum RS1, which causes postharvest apple decay
USDA-ARS?s Scientific Manuscript database
Penicillium species cause postharvest decay, commonly known as blue mold, in pome fruits such as apples and pears. Among the species that cause blue mold, P. expansum is the most virulent and prevalent, while P. solitum is signficantly less virulent. For devising novel strategies to prevent and to r...
The Missing Link: Early Methane ("T") Dwarfs in the Sloan Digital Sky Survey.
Leggett; Geballe; Fan; Schneider; Gunn; Lupton; Knapp; Strauss; McDaniel; Golimowski; Henry; Peng; Tsvetanov; Uomoto; Zheng; Hill; Ramsey; Anderson; Annis; Bahcall; Brinkmann; Chen; Csabai; Fukugita; Hennessy; Hindsley; Ivezic; Lamb; Munn; Pier; Schlegel; Smith; Stoughton; Thakar; York
2000-06-10
We report the discovery of three cool brown dwarfs that fall in the effective temperature gap between the latest L dwarfs currently known, with no methane absorption bands in the 1-2.5 µm range, and the previously known methane (T) dwarfs, whose spectra are dominated by methane and water. The newly discovered objects were detected as very red objects in the Sloan Digital Sky Survey imaging data and have JHK colors between the red L dwarfs and the blue Gl 229B-like T dwarfs. They show both CO and CH(4) absorption in their near-infrared spectra in addition to H(2)O, with weaker CH(4) absorption features in the H and K bands than those in all other methane dwarfs reported to date. Due to the presence of CH(4) in these bands, we propose that these objects are early T dwarfs. The three form part of the brown dwarf spectral sequence and fill in the large gap in the overall spectral sequence from the hottest main-sequence stars to the coolest methane dwarfs currently known.
Evolutionary changes of multiple visual pigment genes in the complete genome of Pacific bluefin tuna
Nakamura, Yoji; Mori, Kazuki; Saitoh, Kenji; Oshima, Kenshiro; Mekuchi, Miyuki; Sugaya, Takuma; Shigenobu, Yuya; Ojima, Nobuhiko; Muta, Shigeru; Fujiwara, Atushi; Yasuike, Motoshige; Oohara, Ichiro; Hirakawa, Hideki; Chowdhury, Vishwajit Sur; Kobayashi, Takanori; Nakajima, Kazuhiro; Sano, Motohiko; Wada, Tokio; Tashiro, Kosuke; Ikeo, Kazuho; Hattori, Masahira; Kuhara, Satoru; Gojobori, Takashi; Inouye, Kiyoshi
2013-01-01
Tunas are migratory fishes in offshore habitats and top predators with unique features. Despite their ecological importance and high market values, the open-ocean lifestyle of tuna, in which effective sensing systems such as color vision are required for capture of prey, has been poorly understood. To elucidate the genetic and evolutionary basis of optic adaptation of tuna, we determined the genome sequence of the Pacific bluefin tuna (Thunnus orientalis), using next-generation sequencing technology. A total of 26,433 protein-coding genes were predicted from 16,802 assembled scaffolds. From these, we identified five common fish visual pigment genes: red-sensitive (middle/long-wavelength sensitive; M/LWS), UV-sensitive (short-wavelength sensitive 1; SWS1), blue-sensitive (SWS2), rhodopsin (RH1), and green-sensitive (RH2) opsin genes. Sequence comparison revealed that tuna's RH1 gene has an amino acid substitution that causes a short-wave shift in the absorption spectrum (i.e., blue shift). Pacific bluefin tuna has at least five RH2 paralogs, the most among studied fishes; four of the proteins encoded may be tuned to blue light at the amino acid level. Moreover, phylogenetic analysis suggested that gene conversions have occurred in each of the SWS2 and RH2 loci in a short period. Thus, Pacific bluefin tuna has undergone evolutionary changes in three genes (RH1, RH2, and SWS2), which may have contributed to detecting blue-green contrast and measuring the distance to prey in the blue-pelagic ocean. These findings provide basic information on behavioral traits of predatory fish and, thereby, could help to improve the technology to culture such fish in captivity for resource management. PMID:23781100
Nakamura, Yoji; Mori, Kazuki; Saitoh, Kenji; Oshima, Kenshiro; Mekuchi, Miyuki; Sugaya, Takuma; Shigenobu, Yuya; Ojima, Nobuhiko; Muta, Shigeru; Fujiwara, Atushi; Yasuike, Motoshige; Oohara, Ichiro; Hirakawa, Hideki; Chowdhury, Vishwajit Sur; Kobayashi, Takanori; Nakajima, Kazuhiro; Sano, Motohiko; Wada, Tokio; Tashiro, Kosuke; Ikeo, Kazuho; Hattori, Masahira; Kuhara, Satoru; Gojobori, Takashi; Inouye, Kiyoshi
2013-07-02
Tunas are migratory fishes in offshore habitats and top predators with unique features. Despite their ecological importance and high market values, the open-ocean lifestyle of tuna, in which effective sensing systems such as color vision are required for capture of prey, has been poorly understood. To elucidate the genetic and evolutionary basis of optic adaptation of tuna, we determined the genome sequence of the Pacific bluefin tuna (Thunnus orientalis), using next-generation sequencing technology. A total of 26,433 protein-coding genes were predicted from 16,802 assembled scaffolds. From these, we identified five common fish visual pigment genes: red-sensitive (middle/long-wavelength sensitive; M/LWS), UV-sensitive (short-wavelength sensitive 1; SWS1), blue-sensitive (SWS2), rhodopsin (RH1), and green-sensitive (RH2) opsin genes. Sequence comparison revealed that tuna's RH1 gene has an amino acid substitution that causes a short-wave shift in the absorption spectrum (i.e., blue shift). Pacific bluefin tuna has at least five RH2 paralogs, the most among studied fishes; four of the proteins encoded may be tuned to blue light at the amino acid level. Moreover, phylogenetic analysis suggested that gene conversions have occurred in each of the SWS2 and RH2 loci in a short period. Thus, Pacific bluefin tuna has undergone evolutionary changes in three genes (RH1, RH2, and SWS2), which may have contributed to detecting blue-green contrast and measuring the distance to prey in the blue-pelagic ocean. These findings provide basic information on behavioral traits of predatory fish and, thereby, could help to improve the technology to culture such fish in captivity for resource management.
A proper motion study of the globular cluster M55
NASA Astrophysics Data System (ADS)
Zloczewski, K.; Kaluzny, J.; Thompson, I. B.
2011-07-01
We have derived the absolute proper motion (PM) of the globular cluster M55 using a large set of CCD images collected with the du Pont telescope between 1997 and 2008. We find (μα cos δ, μδ) = (-3.31 ± 0.10, -9.14 ± 0.15) mas yr-1 relative to background galaxies. Membership status was determined for 16 945 stars with 14 < V < 21 from the central part of the cluster. The PM catalogue includes 52 variables, of which 43 are probable members of M55. This sample not only is dominated by pulsating blue straggler stars, but also includes five eclipsing binaries, three of which are main-sequence objects. The survey also identified several candidate blue, yellow and red straggler stars belonging to the cluster. We detected 15 likely members of the Sgr dSph galaxy located behind M55. The average PM for these stars was measured to be (μα cos δ, μδ) = (-2.23 ± 0.14, -1.83 ± 0.24) mas yr-1.
Color-magnitude distribution of face-on nearby galaxies in Sloan digital sky survey DR7
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jin, Shuo-Wen; Feng, Long-Long; Gu, Qiusheng
2014-05-20
We have analyzed the distributions in the color-magnitude diagram (CMD) of a large sample of face-on galaxies to minimize the effect of dust extinctions on galaxy color. About 300,000 galaxies with log (a/b) < 0.2 and redshift z < 0.2 are selected from the Sloan Digital Sky Survey DR7 catalog. Two methods are employed to investigate the distributions of galaxies in the CMD, including one-dimensional (1D) Gaussian fitting to the distributions in individual magnitude bins and two-dimensional (2D) Gaussian mixture model (GMM) fitting to galaxies as a whole. We find that in the 1D fitting, two Gaussians are not enoughmore » to fit galaxies with the excess present between the blue cloud and the red sequence. The fitting to this excess defines the center of the green valley in the local universe to be (u – r){sub 0.1} = –0.121M {sub r,} 0{sub .1} – 0.061. The fraction of blue cloud and red sequence galaxies turns over around M {sub r,} {sub 0.1} ∼ –20.1 mag, corresponding to stellar mass of 3 × 10{sup 10} M {sub ☉}. For the 2D GMM fitting, a total of four Gaussians are required, one for the blue cloud, one for the red sequence, and the additional two for the green valley. The fact that two Gaussians are needed to describe the distributions of galaxies in the green valley is consistent with some models that argue for two different evolutionary paths from the blue cloud to the red sequence.« less
New Observational Evidence of Flash Mixing on the White Dwarf Cooling Curve
NASA Technical Reports Server (NTRS)
Brown, T. M.; Lanz, T.; Sweigart, A. V.; Cracraft, Misty; Hubeny, Ivan; Landsman, W. B.
2011-01-01
Blue hook stars are a class of subluminous extreme horizontal branch stars that were discovered in UV images of the massive globular clusters w Cen and NGC 2808. These stars occupy a region of the HR diagram that is unexplained by canonical stellar evolution theory. Using new theoretical evolutionary and atmospheric models, we have shown that the blue hook stars are very likely the progeny of stars that undergo extensive internal mixing during a late helium-core flash on the white dwarf cooling curve. This "flash mixing" produces hotter-than-normal EHB stars with atmospheres significantly enhanced in helium and carbon. The larger bolometric correction, combined with the decrease in hydrogen opacity, makes these stars appear sub luminous in the optical and UV. Flash mixing is more likely to occur in stars born with a high helium abundance, due to their lower mass at the main sequence turnoff. For this reason, the phenomenon is more common in those massive globular clusters that show evidence for secondary populations enhanced in helium. However, a high helium abundance does not, by itself, explain the presence of blue hook stars in massive globular clusters. Here, we present new observational evidence for flash mixing, using recent HST observations. These include UV color-magnitude diagrams of six massive globular clusters and far-UV spectroscopy of hot subdwarfs in one of these clusters (NGC 2808).
Population gradient in the Sextans dSph: comprehensive mapping of a dwarf galaxy by Suprime-Cam
NASA Astrophysics Data System (ADS)
Okamoto, S.; Arimoto, N.; Tolstoy, E.; Jablonka, P.; Irwin, M. J.; Komiyama, Y.; Yamada, Y.; Onodera, M.
2017-05-01
We present the deep and wide V and Ic photometry of the Sextans dwarf spheroidal galaxy (dSph) taken by the Suprime-Cam imager on the Subaru Telescope, which extends out to the tidal radius. The colour-magnitude diagram (CMD) reaches two magnitudes below the main-sequence (MS) turn-off, showing a steep red giant branch, a blue and a red horizontal branch (BHB and RHB, respectively), a sub-giant branch (SGB), an MS and blue stragglers (BSs). We construct the radial profile of each evolutionary phase and demonstrate that blue HB stars are more spatially extended, while red HB stars are more centrally concentrated than the other components. The colour distribution of SGB stars also varies with the galactocentric distance; the inner SGB stars shift bluer than those in the outskirts. The radial differences in the CMD morphology indicate the existence of the age gradient. The relatively younger stars (˜10 Gyr) are more centrally concentrated than the older ones (˜13 Gyr). The spatial contour maps of stars in different age bins also show that the younger population has a higher concentration and higher ellipticity than the older one. We also detect the centrally concentrated bright BS stars, the number of which is consistent with the idea that a part of these stars belongs to the remnant of a disrupted star cluster discovered in the previous spectroscopic studies.
Iino, Moritoshi
2006-02-01
Tropisms of higher plants have been investigated for well over a century. Only recently, however, we have begun to establish their mechanisms firmly, mainly thanks to the availability of mutants and genome sequence information. For example, the starch-statolith hypothesis is now best supported as the main mechanism by which plants perceive gravity direction. Phototropins have been identified as the photoreceptors for the major blue-light-sensitive phototropism. Investigations have been extended to elucidate the relationships among tropisms and the controlling roles played by environmental factors, such as light. We are now finding examples in which phototropic and hydrotropic responses are modified through the environmental control of counteracting gravitropism. We are also finding that seedlings generally become phototropically competent only after phytochrome is activated. Such results are providing insights into how plants use tropisms to achieve adaptive growth movements.
Alcaide, Benito; Almendros, Pedro; Aragoncillo, Cristina; Busto, Eduardo; López-Calixto, Carmen G; Liras, Marta; de la Peña O'Shea, Víctor A; García-Sánchez, Alba; Stone, Hannah V
2018-05-28
New azahelicenes having interesting photophysical properties have been prepared in a four-step sequence. These [7]helicenocarbazoles are efficient blue luminophores, demonstrating the utility of gold catalysis in the preparation of advanced materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
USDA-ARS?s Scientific Manuscript database
Penicillium species cause postharvest blue mold decay of apple and pear fruits in the United States and around the world. This genus is responsible for severe economic losses and produces an array of mycotoxins that contaminate processed apple products. Among the species that cause blue mold, isolat...
USDA-ARS?s Scientific Manuscript database
Penicillium species cause postharvest blue mold decay of apples and pears in the United States and in many countries worldwide. This genus is responsible for severe economic losses and produces an array of mycotoxins that contaminate processed apple products. Among the species that cause blue mold,...
A New SNP Haplotype associated with blue disease resistance gene in cotton (Gossypium hirsutum L.)
USDA-ARS?s Scientific Manuscript database
Resistance to cotton blue disease (CBD) was evaluated in 364 F2.3 families of 3 populations derived from resistant variety ‘Delta Opal’. The CBD resistance in ‘Delta Opal’ was controlled by one single dominant gene designated Cbd. Two simple sequence repeat (SSR) markers were identified as linked t...
Zhai, Qiu-ge; Guo, Peng; Zhou, Lin; Liu, Yan-ming
2014-08-01
Graphene oxide was prepared by the modified Hummers method and characterized by field emission scanning electron microscopy. The interaction of graphene with methylene blue was studied by UV absorption, the intensity of two main absorption peaks of methylene blue decreased significantly after the fluorescence was quenched, and the energy transfer didn't occur because the overlap of the absorption spectrum of GO and the emission spectrum of MB is too small. Therefore, the fluorescence quenching of MB and GO was static. When adding a certain amount of Bi3+ in the graphene-methylene blue system, Bi3+ replaces the methylene blue from the graphene-methylene blue complexes because Bi3+ has the smaller volume and is more positively charged. The methylene blue therefore dissociates from the GO-MB complexes, resulting in the recovery of fluorescence of the system. Furthermore, the fluorescence of the system increases with the increase in the amount of Bi3+ due to the enhanced amount of MB in the system. A novel spectrofluorimetric method was therefore developed for the sensitive determination of Bi3+. Some parameters including the concentration of methylene blue, the amount of graphene oxide, the amount of nitric acid and the sequence of reagent adding were optimized to obtain higher sensitivity. The fluorescence of the system was detected at an emission wavelength of 667 nm with excitation at 690 nm. Under the optimized conditions, the concentration of Bi3+ showed good linear relationships with the fluorescence intensity in the range of 0.5-100 micromol x L(-1), with correlation coefficients of r = 0.9955. The limits of detection for Bi3+ was 1.0 x 10(-8) mol x L(-1) (S/N=3). The selectivity of the proposed method was evaluated and the results showed that 1000-fold K+, Ca+, Na+, Mg2+, Cu2+; 100-fold Fe3+, Be2+, SiO2- Al3+, Ni2+, Sb3+, NO3-, Cl-, F-, and 20-fold Pb2+, Hg2+, Cd2+ had negligible interference with the determination of Bi3+. The method has advantages of sensitivity, rapidness and low cost. It was used for the determination of Bi3+ in environmental water samples inclu- ding pond water, rain water and sewage water with recoveries of 93.4%-105.2%.
Detection of a late B star companion of the bright cluster giant C PUP equals HD 63032
NASA Astrophysics Data System (ADS)
Groote, D.; Reimers, D.
1983-03-01
IUE observations show that c Pup, the central bright K giant in the open cluster NGC 2451, has a blue companion. A fit of theoretical line blanketed model atmosphere fluxes to the observed energy distribution yields reddening E(B-V) = 0.15 (from λ2200 Å feature), an effective temperature Te = 10,200K, and an angular diameter θ = 0.060. If the companion is a main-sequence star, c Pup and its companion are located at a distance of 310 ± 50 pc which lends additional support to membership of c Pup in NGC 2451. The evolutionary status of c Pup is briefly discussed.
Isolation and characterization of polymorphic microsatellite markers for blue fox (Alopex lagopus).
Li, Y M; Guo, P C; Lu, J Y; Bai, C Y; Zhao, Z H; Yan, S Q
2016-06-03
The blue fox, belonging to the family Canidae, is a coat color variant of the native arctic fox (Alopex lagopus). To date, microsatellite loci in blue fox are typically amplified using canine simple sequence repeat primers. In the present study, we constructed an (AC)n enrichment library, and isolated and identified 17 polymorphic microsatellite markers for blue fox. The number of alleles per locus is from two to seven based on 24 examined individuals. The expected and observed heterozygosities were in the range of 0.3112 to 0.8236 and 0.2917 to 0.8750, respectively. The polymorphic information content per locus ranged from 0.2583 to 0.8022. These polymorphic markers can be useful for future population genetic studies of both farmed blue foxes and wild arctic foxes.
Bolsheva, Nadezhda L; Melnikova, Nataliya V; Kirov, Ilya V; Speranskaya, Anna S; Krinitsina, Anastasia A; Dmitriev, Alexey A; Belenikin, Maxim S; Krasnov, George S; Lakunina, Valentina A; Snezhkina, Anastasiya V; Rozhmina, Tatiana A; Samatadze, Tatiana E; Yurkevich, Olga Yu; Zoshchuk, Svyatoslav A; Amosova, Аlexandra V; Kudryavtseva, Anna V; Muravenko, Olga V
2017-12-28
The species relationships within the genus Linum have already been studied several times by means of different molecular and phylogenetic approaches. Nevertheless, a number of ambiguities in phylogeny of Linum still remain unresolved. In particular, the species relationships within the sections Stellerolinum and Dasylinum need further clarification. Also, the question of independence of the species of the section Adenolinum still remains unanswered. Moreover, the relationships of L. narbonense and other species of the section Linum require further clarification. Additionally, the origin of tetraploid species of the section Linum (2n = 30) including the cultivated species L. usitatissimum has not been explored. The present study examines the phylogeny of blue-flowered species of Linum by comparisons of 5S rRNA gene sequences as well as ITS1 and ITS2 sequences of 35S rRNA genes. High-throughput sequencing has been used for analysis of multicopy rRNA gene families. In addition to the molecular phylogenetic analysis, the number and chromosomal localization of 5S and 35S rDNA sites has been determined by FISH. Our findings confirm that L. stelleroides forms a basal branch from the clade of blue-flowered flaxes which is independent of the branch formed by species of the sect. Dasylinum. The current molecular phylogenetic approaches, the cytogenetic analysis as well as different genomic DNA fingerprinting methods applied previously did not discriminate certain species within the sect. Adenolinum. The allotetraploid cultivated species L. usitatissimum and its wild ancestor L. angustifolium (2n = 30) could originate either as the result of hybridization of two diploid species (2n = 16) related to the modern L. gandiflorum and L. decumbens, or hybridization of a diploid species (2n = 16) and a diploid ancestor of modern L. narbonense (2n = 14). High-throughput sequencing of multicopy rRNA gene families allowed us to make several adjustments to the phylogeny of blue-flowered flax species and also reveal intra- and interspecific divergence of the rRNA gene sequences.
Su, Yanyan; Mennerich, Artur; Urban, Brigitte
2011-05-01
A wastewater-born and settleable algal-bacterial culture, cultivated in a stirred tank photobioreactor under lab conditions, was used to remove the carbon and nutrients in municipal wastewater and accumulate biomass simultaneously. The algal-bacterial culture showed good settleable property and could totally settle down over 20 min, resulting in a reduction of total suspended solids from an initial 1.84 to 0.016 g/l. The average removal efficiencies of chemical oxygen demand, total kjeldahl nitrogen and phosphate were 98.2 ± 1.3%, 88.3 ± 1.6% and 64.8 ± 1.0% within 8 days, respectively, while the average biomass productivity was 10.9 ± 1.1 g/m(2) · d. Accumulation into biomass, identified as the main nitrogen and phosphorus removal mechanism, accounted for 44.9 ± 0.4% and 61.6 ± 0.5% of total inlet nitrogen and phosphorus, respectively. Microscopic analysis showed the main algae species in the bioreactor were filamentous blue-green algae. Furthermore, denaturing gradient gel electrophoresis and 16S rDNA gene sequencing revealed that the main bacteria present in the photobioreactor were consortia with sequences similar to those of Flavobacteria, Gammaproteobacteria, Bacteroidia and Betaproteobacteria. This study explores a better understanding of an algae-bacteria system and offers new information on further usage of biomass accumulated during treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Liu, Feifan; Zhu, Baoyou; Lu, Gaopeng; Qin, Zilong; Lei, Jiuhou; Peng, Kang-Ming; Chen, Alfred B.; Huang, Anjing; Cummer, Steven A.; Chen, Mingli; Ma, Ming; Lyu, Fanchao; Zhou, Helin
2018-03-01
On 19 August 2012, the Imager of Sprites and Upper Atmospheric Lightning on board the FORMOSAT-2 satellite captured a sequence of seven blue discharges within 1 min that emanated from a parent thunderstorm over Lake Taihu in East China. The analysis of lightning activity produced in the thunderstorm indicates that at least six of these events occurred in association with negative narrow bipolar events (NBEs) that were concurrent with the blue discharge by less than 1 ms, and negative cloud-to-ground occurred within 6 s before each blue discharge, which is in agreement with the modeling presented by Krehbiel et al. (2008). Therefore, the frequent occurrence of negative cloud-to-ground could provide the favorable condition for the production of blue discharges, and negative NBEs are probably the initial event of blue discharges. The detection of negative NBEs might provide a convenient approach to detect the occurrence of blue discharges as lightning bolt shooting upward from the top of energetic thunderstorms.
OBSERVATIONAL CONSTRAINTS ON RED AND BLUE HELIUM BURNING SEQUENCES
DOE Office of Scientific and Technical Information (OSTI.GOV)
McQuinn, Kristen B. W.; Skillman, Evan D.; Dalcanton, Julianne J.
We derive the optical luminosity, colors, and ratios of the blue and red helium burning (HeB) stellar populations from archival Hubble Space Telescope observations of nineteen starburst dwarf galaxies and compare them with theoretical isochrones from Padova stellar evolution models across metallicities from Z = 0.001 to 0.009. We find that the observational data and the theoretical isochrones for both blue and red HeB populations overlap in optical luminosities and colors and the observed and predicted blue to red HeB ratios agree for stars older than 50 Myr over the time bins studied. These findings confirm the usefulness of applyingmore » isochrones to interpret observations of HeB populations. However, there are significant differences, especially for the red HeB population. Specifically, we find (1) offsets in color between the observations and theoretical isochrones of order 0.15 mag (0.5 mag) for the blue (red) HeB populations brighter than M{sub V} {approx} -4 mag, which cannot be solely due to differential extinction; (2) blue HeB stars fainter than M{sub V} {approx} -3 mag are bluer than predicted; (3) the slope of the red HeB sequence is shallower than predicted by a factor of {approx}3; and (4) the models overpredict the ratio of the most luminous blue to red HeB stars corresponding to ages {approx}< 50 Myr. Additionally, we find that for the more metal-rich galaxies in our sample (Z {approx}> 0.5 Z{sub sun}), the red HeB stars overlap with the red giant branch stars in the color-magnitude diagrams, thus reducing their usefulness as indicators of star formation for ages {approx}> 100 Myr.« less
The Blue Straggler Star Population in NGC 1261: Evidence for a Post-core-collapse Bounce State
NASA Astrophysics Data System (ADS)
Simunovic, Mirko; Puzia, Thomas H.; Sills, Alison
2014-11-01
We present a multi-passband photometric study of the Blue Straggler Star (BSS) population in the Galactic globular cluster (GC) NGC 1261, using available space- and ground-based survey data. The inner BSS population is found to have two distinct sequences in the color-magnitude diagram (CMD), similar to double BSS sequences detected in other GCs. These well defined sequences are presumably linked to single short-lived events such as core collapse, which are expected to boost the formation of BSSs. In agreement with this, we find a BSS sequence in NGC 1261 which can be well reproduced individually by a theoretical model prediction of a 2 Gyr old population of stellar collision products, which are expected to form in the denser inner regions during short-lived core contraction phases. Additionally, we report the occurrence of a group of BSSs with unusually blue colors in the CMD, which are consistent with a corresponding model of a 200 Myr old population of stellar collision products. The properties of the NGC 1261 BSS populations, including their spatial distributions, suggest an advanced dynamical evolutionary state of the cluster, but the core of this GC does not show the classical signatures of core collapse. We argue that these apparent contradictions provide evidence for a post-core-collapse bounce state seen in dynamical simulations of old GCs.
NASA Astrophysics Data System (ADS)
Martinet, Nicolas; Durret, Florence; Guennou, Loïc; Adami, Christophe; Biviano, Andrea; Ulmer, Melville P.; Clowe, Douglas; Halliday, Claire; Ilbert, Olivier; Márquez, Isabel; Schirmer, Mischa
2015-03-01
Context. There is some disagreement about the abundance of faint galaxies in high-redshift clusters, with contradictory results in the literature arising from studies of the optical galaxy luminosity function (GLF) for small cluster samples. Aims: We compute GLFs for one of the largest medium-to-high-redshift (0.4 ≤ z < 0.9) cluster samples to date in order to probe the abundance of faint galaxies in clusters. We also study how the GLF depends on cluster redshift, mass, and substructure and compare the GLFs of clusters with those of the field. We separately investigate the GLFs of blue and red-sequence (RS) galaxies to understand the evolution of different cluster populations. Methods: We calculated the GLFs for 31 clusters taken from the DAFT/FADA survey in the B,V,R, and I rest-frame bands. We used photometric redshifts computed from BVRIZJ images to constrain galaxy cluster membership. We carried out a detailed estimate of the completeness of our data. We distinguished the red-sequence and blue galaxies using a V - I versus I colour-magnitude diagram. We studied the evolution of these two populations with redshift. We fitted Schechter functions to our stacked GLFs to determine average cluster characteristics. Results: We find that the shapes of our GLFs are similar for the B,V,R, and I bands with a drop at the red GLF faint ends that is more pronounced at high redshift: αred ~ -0.5 at 0.40 ≤ z < 0.65 and αred > 0.1 at 0.65 ≤ z < 0.90. The blue GLFs have a steeper faint end (αblue ~ -1.6) than the red GLFs, which appears to be independent of redshift. For the full cluster sample, blue and red GLFs meet at MV = -20, MR = -20.5, and MI = -20.3. A study of how galaxy types evolve with redshift shows that late-type galaxies appear to become early types between z ~ 0.9 and today. Finally, the faint ends of the red GLFs of more massive clusters appear to be richer than less massive clusters, which is more typical of the lower redshift behaviour. Conclusions: Our results indicate that these clusters form at redshifts higher than z = 0.9 from galaxy structures that already have an established red sequence. Late-type galaxies then appear to evolve into early types, enriching the red sequence between this redshift and today. This effect is consistent with the evolution of the faint-end slope of the red sequence and the galaxy type evolution that we find. Finally, faint galaxies accreted from the field environment at all redshifts might have replaced the blue late-type galaxies that converted into early types, explaining the lack of evolution in the faint-end slopes of the blue GLFs. Appendix is available in electronic form at http://www.aanda.org
OuYang, Fangqun; Mao, Jian-Feng; Wang, Junhui; Zhang, Shougong; Li, Yue
2015-01-01
The mechanisms by which different light spectra regulate plant shoot elongation vary, and phytohormones respond differently to such spectrum-associated regulatory effects. Light supplementation can effectively control seedling growth in Norway spruce. However, knowledge of the effective spectrum for promoting growth and phytohormone metabolism in this species is lacking. In this study, 3-year-old Norway spruce clones were illuminated for 12 h after sunset under blue or red light-emitting diode (LED) light for 90 d, and stem increments and other growth traits were determined. Endogenous hormone levels and transcriptome differences in the current needles were assessed to identify genes related to the red and blue light regulatory responses. The results showed that the stem increment and gibberellin (GA) levels of the seedlings illuminated by red light were 8.6% and 29.0% higher, respectively, than those of the seedlings illuminated by blue light. The indoleacetic acid (IAA) level of the seedlings illuminated by red light was 54.6% lower than that of the seedlings illuminated by blue light, and there were no significant differences in abscisic acid (ABA) or zeatin riboside [ZR] between the two groups of seedlings. The transcriptome results revealed 58,736,166 and 60,555,192 clean reads for the blue-light- and red-light-illuminated samples, respectively. Illumina sequencing revealed 21,923 unigenes, and 2744 (approximately 93.8%) out of 2926 differentially expressed genes (DEGs) were found to be upregulated under blue light. The main KEGG classifications of the DEGs were metabolic pathway (29%), biosynthesis of secondary metabolites (20.49%) and hormone signal transduction (8.39%). With regard to hormone signal transduction, AUXIN-RESISTANT1 (AUX1), AUX/IAA genes, auxin-inducible genes, and early auxin-responsive genes [(auxin response factor (ARF) and small auxin-up RNA (SAUR)] were all upregulated under blue light compared with red light, which might have yielded the higher IAA level. DELLA and phytochrome-interacting factor 3 (PIF3), involved in negative GA signaling, were also upregulated under blue light, which may be related to the lower GA level. Light quality also affects endogenous hormones by influencing secondary metabolism. Blue light promoted phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis and flavone and flavonol biosynthesis, accompanied by upregulation of most of the genes in their pathways. In conclusion, red light may promote stem growth by regulating biosynthesis of GAs, and blue light may promote flavonoid, lignin, phenylpropanoid and some hormones (such as jasmonic acid) which were related to plant defense in Norway spruce, which might reduce the primary metabolites available for plant growth.
Rapid alkaline methylene blue supravital staining for assessment of anterior segment infections.
Kiuchi, Katsuji
2016-01-01
To present the Löffler's alkaline methylene blue technique of staining eye discharges in eyes with anterior segment infections. The Löffler's alkaline methylene blue staining method is a simple staining technique that can be used to differentiate bacterial, viral, and fungal infections. It is a cationic dye that stains cells blue because the positively charged dye is attracted to negatively charged particles such as polyphosphates, DNAs, and RNAs. Specimens collected from patients by swabbing are smeared onto microscope slides and the methylene blue solution is dropped on the slide. The slide is covered with a glass cover slip and examined under a microscope. The entire time from the collection to the viewing is about 30 seconds. Histopathological images of the conjunctival epithelial cells and neutrophils in eye discharges were dyed blue and the nuclei were stained more intensely blue. Bacterial infections consisted mainly of neutrophils, and viral infections consisted mainly of lymphocytes. Löffler's alkaline methylene blue staining can be done in about 30 seconds for diagnosis. Even though this is a one color stain, it is possible to infer the cause of the infection by detection of the absence of bacteria and/or fungi in context of the differential distribution of neutrophils and lymphocytes.
GREEN GALAXIES IN THE COSMOS FIELD
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pan, Zhizheng; Kong, Xu; Fan, Lulu, E-mail: panzz@mail.ustc.edu.cn, E-mail: xkong@ustc.edu.cn
2013-10-10
We present research on the morphologies, spectra, and environments of ≈2350 'green valley' galaxies at 0.2 < z < 1.0 in the COSMOS field. The bimodality of dust-corrected NUV–r {sup +} color is used to define 'green valley'; it removes dusty star-forming galaxies from galaxies that are truly transitioning between the blue cloud and the red sequence. Morphological parameters of green galaxies are intermediate between those of blue and red galaxy populations, both on the Gini-asymmetry and the Gini-M{sub 20} planes. Approximately 60%-70% of green disk galaxies have intermediate or big bulges, and only 5%-10% are pure disk systems, basedmore » on morphological classification using the Zurich Estimator of Structural Types. The obtained average spectra of green galaxies are intermediate between blue and red ones in terms of [O II], Hα, and Hβ emission lines. Stellar population synthesis on the average spectra shows that green galaxies are on average older than blue galaxies but younger than red galaxies. Green galaxies and blue galaxies have similar projected galaxy density (Σ{sub 10}) distributions at z > 0.7. At z < 0.7, the fractions of M{sub *} < 10{sup 10.0} M{sub ☉} green galaxies located in a dense environment are found to be significantly larger than those of blue galaxies. The morphological and spectral properties of green galaxies are consistent with the transitioning population between the blue cloud and the red sequence. The possible mechanisms for quenching star formation activities in green galaxies are discussed. The importance of active galactic nucleus feedback cannot be well constrained in our study. Finally, our findings suggest that environmental conditions, most likely starvation and harassment, significantly affect the transformation of M{sub *} < 10{sup 10.0} M{sub ☉} blue galaxies into red galaxies, especially at z < 0.5.« less
KPC-SCALE STUDY OF SUBSTRUCTURES INSIDE GALAXIES out to z ~ 1.3
NASA Astrophysics Data System (ADS)
Hemmati, Shoubaneh; Mobasher, B.; Miller, S.; Nayyeri, H.
2014-01-01
Studying the resolved properties of galaxies in kpc scale has the capability to address major questions in galaxy structure formation and stellar properties evolution. We use a unique sample of 129 morphologically inclusive disk-like galaxies in the redshift range 0.2
The blue supergiant MN18 and its bipolar circumstellar nebula
NASA Astrophysics Data System (ADS)
Gvaramadze, V. V.; Kniazev, A. Y.; Bestenlehner, J. M.; Bodensteiner, J.; Langer, N.; Greiner, J.; Grebel, E. K.; Berdnikov, L. N.; Beletsky, Y.
2015-11-01
We report the results of spectrophotometric observations of the massive star MN18 revealed via discovery of a bipolar nebula around it with the Spitzer Space Telescope. Using the optical spectrum obtained with the Southern African Large Telescope, we classify this star as B1 Ia. The evolved status of MN18 is supported by the detection of nitrogen overabundance in the nebula, which implies that it is composed of processed material ejected by the star. We analysed the spectrum of MN18 by using the code CMFGEN, obtaining a stellar effective temperature of ≈21 kK. The star is highly reddened, E(B - V) ≈ 2 mag. Adopting an absolute visual magnitude of MV = -6.8 ± 0.5 (typical of B1 supergiants), MN18 has a luminosity of log L/L⊙ ≈ 5.42 ± 0.30, a mass-loss rate of ≈(2.8-4.5) × 10- 7 M⊙ yr- 1, and resides at a distance of ≈5.6^{+1.5} _{-1.2} kpc. We discuss the origin of the nebula around MN18 and compare it with similar nebulae produced by other blue supergiants in the Galaxy (Sher 25, HD 168625, [SBW2007] 1) and the Large Magellanic Cloud (Sk-69°202). The nitrogen abundances in these nebulae imply that blue supergiants can produce them from the main-sequence stage up to the pre-supernova stage. We also present a K-band spectrum of the candidate luminous blue variable MN56 (encircled by a ring-like nebula) and report the discovery of an OB star at ≈17 arcsec from MN18. The possible membership of MN18 and the OB star of the star cluster Lynga 3 is discussed.
Protein and gene structure of a blue laccase from Pleurotus ostreatus1.
Giardina, P; Palmieri, G; Scaloni, A; Fontanella, B; Faraco, V; Cennamo, G; Sannia, G
1999-01-01
A new laccase isoenzyme (POXA1b, where POX is phenol oxidase), produced by Pleurotus ostreatus in cultures supplemented with copper sulphate, has been purified and fully characterized. The main characteristics of this protein (molecular mass in native and denaturing conditions, pI and catalytic properties) are almost identical to the previously studied laccase POXA1w. However, POXA1b contains four copper atoms per molecule instead of one copper, two zinc and one iron atom per molecule of POXA1w. Furthermore, POXA1b shows an unusually high stability at alkaline pH. The gene and cDNA coding for POXA1b have been cloned and sequenced. The gene coding sequence contains 1599 bp, interrupted by 15 introns. Comparison of the structure of the poxa1b gene with the two previously studied P. ostreatus laccase genes (pox1 and poxc) suggests that these genes belong to two different subfamilies. The amino acid sequence of POXA1b deduced from the cDNA sequence has been almost completely verified by means of matrix-assisted laser desorption ionization MS. It has been demonstrated that three out of six putative glycosylation sites are post-translationally modified and the structure of the bound glycosidic moieties has been determined, whereas two other putative glycosylation sites are unmodified. PMID:10417329
The initial mass function and star formation law in the outer disc of NGC 2915
NASA Astrophysics Data System (ADS)
Bruzzese, S. M.; Meurer, G. R.; Lagos, C. D. P.; Elson, E. C.; Werk, J. K.; Blakeslee, John P.; Ford, H.
2015-02-01
Using Hubble Space Telescope (HST) Advanced Camera for Surveys/Wide Field Camera data we present the photometry and spatial distribution of resolved stellar populations in the outskirts of NGC 2915, a blue compact dwarf with an extended H I disc. These observations reveal an elliptical distribution of red giant branch stars, and a clumpy distribution of main-sequence stars that correlate with the H I gas distribution. We constrain the upper-end initial mass function (IMF) and determine the star formation law (SFL) in this field, using the observed main-sequence stars and an assumed constant star formation rate. Previously published Hα observations of the field, which show one faint H II region, are used to provide further constraints on the IMF. We find that the main-sequence luminosity function analysis alone results in a best-fitting IMF with a power-law slope α = -2.85 and upper-mass limit M_u = 60 M_{⊙}. However, if we assume that all Hα emission is confined to H II regions then the upper-mass limit is restricted to M_u ≲ 20 M_{⊙}. For the luminosity function fit to be correct, we have to discount the Hα observations implying significant diffuse ionized gas or escaping ionizing photons. Combining the HST photometry with H I imaging, we find the SFL has a power-law index N = 1.53 ± 0.21. Applying these results to the entire outer H I disc indicates that it contributes 11-28 per cent of the total recent star formation in NGC 2915, depending on whether the IMF is constant within the disc or varies from the centre to the outer region.
NASA Astrophysics Data System (ADS)
Milone, A. P.; Bedin, L. R.; Piotto, G.; Marino, A. F.; Cassisi, S.; Bellini, A.; Jerjen, H.; Pietrinferni, A.; Aparicio, A.; Rich, R. M.
2015-07-01
Recent studies have shown that the extended main-sequence turn-off (eMSTO) is a common feature of intermediate-age star clusters in the Magellanic Clouds (MCs). The most simple explanation is that these stellar systems harbour multiple generations of stars with an age difference of a few hundred million years. However, while an eMSTO has been detected in a large number of clusters with ages between ˜1-2 Gyr, several studies of young clusters in both MCs and in nearby galaxies do not find any evidence for a prolonged star formation history, i. e. for multiple stellar generations. These results have suggested alternative interpretation of the eMSTOs observed in intermediate-age star clusters. The eMSTO could be due to stellar rotation mimicking an age spread or to interacting binaries. In these scenarios, intermediate-age MC clusters would be simple stellar populations, in close analogy with younger clusters. Here, we provide the first evidence for an eMSTO in a young stellar cluster. We exploit multiband Hubble Space Telescope photometry to study the ˜300-Myr old star cluster NGC 1856 in the Large Magellanic Cloud and detected a broadened MSTO that is consistent with a prolonged star formation which had a duration of about 150 Myr. Below the turn-off, the main sequence (MS) of NGC 1856 is split into a red and blue component, hosting 33 ± 5 and 67 ± 5 per cent of the total number of MS stars, respectively. We discuss these findings in the context of multiple-stellar-generation, stellar-rotation, and interacting-binary hypotheses.
iMARS--mutation analysis reporting software: an analysis of spontaneous cII mutation spectra.
Morgan, Claire; Lewis, Paul D
2006-01-31
The sensitivity of any mutational assay is determined by the level at which spontaneous mutations occur in the corresponding untreated controls. Establishing the type and frequency at which mutations occur naturally within a test system is essential if one is to draw scientifically sound conclusions regarding chemically induced mutations. Currently, mutation-spectra analysis is laborious and time-consuming. Thus, we have developed iMARS, a comprehensive mutation-spectrum analysis package that utilises routinely used methodologies and visualisation tools. To demonstrate the use and capabilities of iMARS, we have analysed the distribution, types and sequence context of spontaneous base substitutions derived from the cII gene mutation assay in transgenic animals. Analysis of spontaneous mutation spectra revealed variation both within and between the transgenic rodent test systems Big Blue Mouse, MutaMouse and Big Blue Rat. The most common spontaneous base substitutions were G:C-->A:T transitions and G:C-->T:A transversions. All Big Blue Mouse spectra were significantly different from each other by distribution and nearly all by mutation type, whereas the converse was true for the other test systems. Twenty-eight mutation hotspots were observed across all spectra generally occurring in CG, GA/TC, GG and GC dinucleotides. A mutation hotspot at nucleotide 212 occurred at a higher frequency in MutaMouse and Big Blue Rat. In addition, CG dinucleotides were the most mutable in all spectra except two Big Blue Mouse spectra. Thus, spontaneous base-substitution spectra showed more variation in distribution, type and sequence context in Big Blue Mouse relative to spectra derived from MutaMouse and Big Blue Rat. The results of our analysis provide a baseline reference for mutation studies utilising the cII gene in transgenic rodent models. The potential differences in spontaneous base-substitution spectra should be considered when making comparisons between these test systems. The ease at which iMARS has allowed us to carry out an exhaustive investigation to assess mutation distribution, mutation type, strand bias, target sequences and motifs, as well as predict mutation hotspots provides us with a valuable tool in helping to distinguish true chemically induced hotspots from background mutations and gives a true reflection of mutation frequency.
Evolution of early life inferred from protein and ribonucleic acid sequences
NASA Technical Reports Server (NTRS)
Dayhoff, M. O.; Schwartz, R. M.
1978-01-01
The chemical structures of ferredoxin, 5S ribosomal RNA, and c-type cytochrome sequences have been employed to construct a phylogenetic tree which connects all major photosynthesizing organisms: the three types of bacteria, blue-green algae, and chloroplasts. Anaerobic and aerobic bacteria, eukaryotic cytoplasmic components and mitochondria are also included in the phylogenetic tree. Anaerobic nonphotosynthesizing bacteria similar to Clostridium were the earliest organisms, arising more than 3.2 billion years ago. Bacterial photosynthesis evolved nearly 3.0 billion years ago, while oxygen-evolving photosynthesis, originating in the blue-green algal line, came into being about 2.0 billion years ago. The phylogenetic tree supports the symbiotic theory of the origin of eukaryotes.
USDA-ARS?s Scientific Manuscript database
The blue crab, Callinectes sapidus (Rathbun 1896), which is a commercially important trophic link in coastal ecosystems of the western Atlantic, is infected in both North and South America by C. sapidus Reovirus 1 (CsRV1), a double stranded RNA virus. The 12 genome segments of a North American strai...
Laurinaviciene, Aida; Plancoulaine, Benoit; Baltrusaityte, Indra; Meskauskas, Raimundas; Besusparis, Justinas; Lesciute-Krilaviciene, Daiva; Raudeliunas, Darius; Iqbal, Yasir; Herlin, Paulette; Laurinavicius, Arvydas
2014-01-01
Digital immunohistochemistry (IHC) is one of the most promising applications brought by new generation image analysis (IA). While conventional IHC staining quality is monitored by semi-quantitative visual evaluation of tissue controls, IA may require more sensitive measurement. We designed an automated system to digitally monitor IHC multi-tissue controls, based on SQL-level integration of laboratory information system with image and statistical analysis tools. Consecutive sections of TMA containing 10 cores of breast cancer tissue were used as tissue controls in routine Ki67 IHC testing. Ventana slide label barcode ID was sent to the LIS to register the serial section sequence. The slides were stained and scanned (Aperio ScanScope XT), IA was performed by the Aperio/Leica Colocalization and Genie Classifier/Nuclear algorithms. SQL-based integration ensured automated statistical analysis of the IA data by the SAS Enterprise Guide project. Factor analysis and plot visualizations were performed to explore slide-to-slide variation of the Ki67 IHC staining results in the control tissue. Slide-to-slide intra-core IHC staining analysis revealed rather significant variation of the variables reflecting the sample size, while Brown and Blue Intensity were relatively stable. To further investigate this variation, the IA results from the 10 cores were aggregated to minimize tissue-related variance. Factor analysis revealed association between the variables reflecting the sample size detected by IA and Blue Intensity. Since the main feature to be extracted from the tissue controls was staining intensity, we further explored the variation of the intensity variables in the individual cores. MeanBrownBlue Intensity ((Brown+Blue)/2) and DiffBrownBlue Intensity (Brown-Blue) were introduced to better contrast the absolute intensity and the colour balance variation in each core; relevant factor scores were extracted. Finally, tissue-related factors of IHC staining variance were explored in the individual tissue cores. Our solution enabled to monitor staining of IHC multi-tissue controls by the means of IA, followed by automated statistical analysis, integrated into the laboratory workflow. We found that, even in consecutive serial tissue sections, tissue-related factors affected the IHC IA results; meanwhile, less intense blue counterstain was associated with less amount of tissue, detected by the IA tools.
2014-01-01
Background Digital immunohistochemistry (IHC) is one of the most promising applications brought by new generation image analysis (IA). While conventional IHC staining quality is monitored by semi-quantitative visual evaluation of tissue controls, IA may require more sensitive measurement. We designed an automated system to digitally monitor IHC multi-tissue controls, based on SQL-level integration of laboratory information system with image and statistical analysis tools. Methods Consecutive sections of TMA containing 10 cores of breast cancer tissue were used as tissue controls in routine Ki67 IHC testing. Ventana slide label barcode ID was sent to the LIS to register the serial section sequence. The slides were stained and scanned (Aperio ScanScope XT), IA was performed by the Aperio/Leica Colocalization and Genie Classifier/Nuclear algorithms. SQL-based integration ensured automated statistical analysis of the IA data by the SAS Enterprise Guide project. Factor analysis and plot visualizations were performed to explore slide-to-slide variation of the Ki67 IHC staining results in the control tissue. Results Slide-to-slide intra-core IHC staining analysis revealed rather significant variation of the variables reflecting the sample size, while Brown and Blue Intensity were relatively stable. To further investigate this variation, the IA results from the 10 cores were aggregated to minimize tissue-related variance. Factor analysis revealed association between the variables reflecting the sample size detected by IA and Blue Intensity. Since the main feature to be extracted from the tissue controls was staining intensity, we further explored the variation of the intensity variables in the individual cores. MeanBrownBlue Intensity ((Brown+Blue)/2) and DiffBrownBlue Intensity (Brown-Blue) were introduced to better contrast the absolute intensity and the colour balance variation in each core; relevant factor scores were extracted. Finally, tissue-related factors of IHC staining variance were explored in the individual tissue cores. Conclusions Our solution enabled to monitor staining of IHC multi-tissue controls by the means of IA, followed by automated statistical analysis, integrated into the laboratory workflow. We found that, even in consecutive serial tissue sections, tissue-related factors affected the IHC IA results; meanwhile, less intense blue counterstain was associated with less amount of tissue, detected by the IA tools. PMID:25565007
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Xiaohan; Li, Chengyuan; De Grijs, Richard
While the extended main-sequence turnoffs (eMSTOs) found in almost all 1–2 Gyr old star clusters in the Magellanic Clouds are often explained by postulating extended star formation histories (SFHs), the tight subgiant branches (SGBs) seen in some clusters challenge this popular scenario. Puzzlingly, the SGB of the eMSTO cluster NGC 419 is significantly broader at bluer than at redder colors. We carefully assess and confirm the reality of this observational trend. If we would assume that the widths of the features in color–magnitude space were entirely owing to a range in stellar ages, the SFHs of the eMSTO stars andmore » the blue SGB region would be significantly more prolonged than that of the red part of the SGB. This cannot be explained by assuming an internal age spread. We show that rotational deceleration of a population of rapidly rotating stars, a currently hotly debated alternative scenario, naturally explains the observed trend along the SGB. Our analysis shows that a “converging” SGB could be produced if the cluster is mostly composed of rapidly rotating stars that slow down over time owing to the conservation of angular momentum during their evolutionary expansion from main-sequence turnoff stars to red giants.« less
Deep HST Photometry of NGC 6388: Age and Horizontal Branch Luminosity
NASA Technical Reports Server (NTRS)
Stetson, Peter B.; Catelan, M.; Pritzl, Barton J.; Smith, Horace A.; Kinemuchi, Karen; Layden, Andrew C.; Sweigart, Allen V.; Rich, R. M.
2006-01-01
We present the first deep color-magnitude diagram (CMD) of the Galactic globular cluster NGC 6388, obtained with the Hubble Space Telescope, that is able to reach the main-sequence turnoff point of the cluster. From a detailed comparison between the cluster CMD and that of 47 Tucanae (NGC 104), we find that the bulk of the stars in these two clusters have nearly the same age and chemical composition. On the other hand, our results indicate that the blue horizontal branch and RR Lyrae components in NGC 6388 are intrinsically over-luminous, which must be due to one or more, still undetermined, non-canonical second parameter(s) affecting a relatively minor fraction of the stars in NGC 6388.
The Galaxy Color-Magnitude Diagram in the Local Universe from GALEX and SDSS Data
NASA Astrophysics Data System (ADS)
Wyder, T. K.; GALEX Science Team
2005-12-01
We present the relative density of galaxies in the local universe as a function of their r-band absolute magnitudes and ultraviolet minus r-band colors. The Sloan Digital Sky Survey (SDSS) main galaxy sample selected in the r-band was matched with a sample of galaxies from the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey in both the far-UV (FUV) and near-UV (NUV) bands. Simlar to previous optical studies, the distribution of galaxies in (FUV-r) and (NUV-r) is bimodal with well-defined blue and red sequences. We compare the distribution of galaxies in these colors with both the D4000 index measured from the SDSS spectra as well as the SDSS (u-r) color.
GALAXY EVOLUTION IN THE MID-INFRARED GREEN VALLEY: A CASE OF THE A2199 SUPERCLUSTER
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Gwang-Ho; Lee, Myung Gyoon; Sohn, Jubee
2015-02-20
We study the mid-infrared (MIR) properties of the galaxies in the A2199 supercluster at z = 0.03 to understand the star formation activity of galaxy groups and clusters in the supercluster environment. Using the Wide-field Infrared Survey Explorer data, we find no dependence of mass-normalized integrated star formation rates of galaxy groups/clusters on their virial masses. We classify the supercluster galaxies into three classes in the MIR color-luminosity diagram: MIR blue cloud (massive, quiescent, and mostly early-type), MIR star-forming sequence (mostly late-type), and MIR green valley galaxies. These MIR green valley galaxies are distinguishable from the optical green valley galaxiesmore » in the sense that they belong to the optical red sequence. We find that the fraction of each MIR class does not depend on the virial mass of each group/cluster. We compare the cumulative distributions of surface galaxy number density and cluster/group-centric distance for the three MIR classes. MIR green valley galaxies show the distribution between MIR blue cloud and MIR star-forming (SF) sequence galaxies. However, if we fix galaxy morphology, early- and late-type MIR green valley galaxies show different distributions. Our results suggest a possible evolutionary scenario of these galaxies: (1) late-type MIR SF sequence galaxies → (2) late-type MIR green valley galaxies → (3) early-type MIR green valley galaxies → (4) early-type MIR blue cloud galaxies. In this sequence, the star formation of galaxies is quenched before the galaxies enter the MIR green valley, and then morphological transformation occurs in the MIR green valley.« less
The Clusters AgeS Experiment (CASE). Variable Stars in the Field of the Globular Cluster NGC 6362
NASA Astrophysics Data System (ADS)
Kaluzny, J.; Thompson, I. B.; Rozyczka, M.; Pych, W.; Narloch, W.
2014-12-01
The field of the globular cluster NGC 6362 was monitored between 1995 and 2009 in a search for variable stars. BV light curves were obtained for 69 periodic variable stars including 34 known RR Lyr stars, 10 known objects of other types and 25 newly detected variable stars. Among the latter we identified 18 proper-motion members of the cluster: seven detached eclipsing binaries (DEBs), six SX Phe stars, two W UMa binaries, two spotted red giants, and a very interesting eclipsing binary composed of two red giants - the first example of such a system found in a globular cluster. Five of the DEBs are located at the turnoff region, and the remaining two are redward of the lower main sequence. Eighty-four objects from the central 9×9 arcmin2 of the cluster were found in the region of cluster blue stragglers. Of these 70 are proper motion (PM) members of NGC 6362 (including all SX Phe and two W UMa stars), and five are field stars. The remaining nine objects lacking PM information are located at the very core of the cluster, and as such they are likely genuine blue stragglers.
Tracking the blue: a MLST approach to characterise the Pseudomonas fluorescens group.
Andreani, N A; Martino, M E; Fasolato, L; Carraro, L; Montemurro, F; Mioni, R; Bordin, P; Cardazzo, B
2014-05-01
The Pseudomonas fluorescens group comprises several closely related species that are involved in food contamination and spoilage. Specifically, the interest in P. fluorescens as a spoiler of dairy products increased after the cases of "blue mozzarella" that occurred in Italy in 2010. A Multilocus Sequence Typing (MLST) scheme was developed and applied to characterise 136 isolates (reference strains and food borne isolates) at strain level, to reveal the genetic relationships among them and to disclose any possible genetic clustering of phenotypic markers involved in food spoilage (protease, lipase, lecithinase activities and pigmented or fluorescent molecule production). The production of dark blue diffusible pigment was evaluated on several bacterial culture media and directly on mozzarella cheese. The MLST scheme provided precise genotyping at the strain level, and the population analyses of the concatenated sequences allowed major taxa to be defined. This approach was revealed to be suitable for tracking the strains according to their origin, such as dairy plants or food matrices. The genetic analysis revealed the presence of a connection between the blue pigment production and a specific phylogenetic cluster. The development of the online database specific to the P. fluorescens group (http://pubmlst.org/pfluorescens) will facilitate the application of the scheme and the sharing of the data. Copyright © 2013 Elsevier Ltd. All rights reserved.
Reprint of 'Tracking the blue: a MLST approach to characterise the Pseudomonas fluorescens group'.
Andreani, N A; Martino, M E; Fasolato, L; Carraro, L; Montemurro, F; Mioni, R; Bordin, P; Cardazzo, B
2015-02-01
The Pseudomonas fluorescens group comprises several closely related species that are involved in food contamination and spoilage. Specifically, the interest in P. fluorescens as a spoiler of dairy products increased after the cases of "blue mozzarella" that occurred in Italy in 2010. A Multilocus Sequence Typing (MLST) scheme was developed and applied to characterise 136 isolates (reference strains and food borne isolates) at strain level, to reveal the genetic relationships among them and to disclose any possible genetic clustering of phenotypic markers involved in food spoilage (protease, lipase, lecithinase activities and pigmented or fluorescent molecule production). The production of dark blue diffusible pigment was evaluated on several bacterial culture media and directly on mozzarella cheese. The MLST scheme provided precise genotyping at the strain level, and the population analyses of the concatenated sequences allowed major taxa to be defined. This approach was revealed to be suitable for tracking the strains according to their origin, such as dairy plants or food matrices. The genetic analysis revealed the presence of a connection between the blue pigment production and a specific phylogenetic cluster. The development of the online database specific to the P. fluorescens group (http://pubmlst.org/pfluorescens) will facilitate the application of the scheme and the sharing of the data. Copyright © 2014. Published by Elsevier Ltd.
Expression and characterization of novel laccase gene from Pandoraea sp. ISTKB and its application.
Kumar, Madan; Mishra, Arti; Singh, Shashi Shekhar; Srivastava, Shaili; Thakur, Indu Shekhar
2018-04-14
In the present study, a non-blue laccase gene from previously reported lignin degrading bacterium, Pandoraea sp. ISTKB, was isolated, cloned and expressed in E. coli. Bioinformatics analysis of sequence discovered twin-arginine translocation signal sequence, copper binding motifs and presence of more random coil compare to helices and sheets in structure. The enzyme was found to be active on wide pH range and the pH optima was observed at pH 4 and 8 on substrate 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and 2,6-Dimethoxyphenol respectively. This is a thermophilic enzyme with maximum activity around 50-70 °C. The enzyme was further characterized by spectroscopy, reaction kinetics and effect of metal ions and inhibitors were studied. Compared to laccase alone; the treatment of dyes with laccase plus mediator resulted in enhanced decolorization of crystal violet, methylene blue, azure B, carmine and Congo red but the effect of mediator was not observed on trypan blue. Laccase treatment triggered polymerization on vanillic acid (VA) and kraft lignin (KL). Laccase plus mediator treatment reversed the polymerization and resulted in transformation or degradation of VA and KL. This thermophilic and alkalophilic non-blue laccase from Pandoraea sp. ISTKB is promising with prospective biotechnological application. Copyright © 2018. Published by Elsevier B.V.
44. Blue Coal Corporation Office Building (foreground), Huber Breaker (left), ...
44. Blue Coal Corporation Office Building (foreground), Huber Breaker (left), Retail Coal Storage Bins (far center) Photograph taken by George Harven - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA
Tan, Shuai; Zou, Dandan; Tang, Lei; Wang, Gaochao; Peng, Quekun; Zeng, Bo; Zhang, Chen; Zou, Fangdong
2012-06-01
Blue sheep (Pseudois nayaur), a Central Asian ungulate with restricted geographic distribution, exhibits unclear variation in morphology and phylogeographic structure. The composition of species and subspecies in the genus Pseudois is controversial, particularly with respect to the taxonomic designation of geographically restricted populations. Here, 26 specimens including 5 dwarf blue sheep (Pseudois schaeferi), which were collected from a broad geographic region in China, were analyzed for 2 mitochondrial DNA fragments (cytochrome b and control region sequences). In a pattern consistent with geographically defined subspecies, we found three deeply divergent mitochondrial lineages restricted to different geographic regions. The currently designated two subspecies of blue sheep, Pseudois nayaur nayaur and Pseudois nayaur szechuanensis, were recognized in the phylogenetic trees. In addition, the Helan Mountain population showed distinct genetic characteristics from other geographic populations, and thus should be classified as a new subspecies. In contrast, dwarf blue sheep clustered closely with some blue sheep from Sichuan Province in the phylogenetic trees. Therefore, dwarf blue sheep appear to be a subset of Pseudois nayaur szechuanensis. After considering both population genetic information and molecular clock analysis, we obtained some relevant molecular phylogeographic information concerning the historical biogeography of blue sheep. These results also indicate that western Sichuan was a potential refugium for blue sheep during the Quaternary period.
Morphological responses of wheat to blue light
NASA Technical Reports Server (NTRS)
Barnes, C.; Bugbee, B.
1992-01-01
Blue light significantly increased tillering in wheat (Triticum aestivum L.) plants grown at the same photosynthetic photon flux (PPF). Plants were grown under two levels of blue light (400-500 nm) in a controlled environment with continuous irradiation. Plants received either 50 micromoles m-2 s-1 of blue light or 2 micromoles m-2 s-1 blue light from filtered metal halide lamps at a total irradiance of 200 micromoles m-2 s-1 PPF (400-700 nm). Plants tillered an average of 25% more under the higher level of blue light. Blue light also caused a small, but consistent, increase in main culm development, measured as Haun stage. Leaf length was reduced by higher levels of blue light, while plant dry-mass was not significantly affected by blue light. Applying the principle of equivalent light action, the results suggest that tillering and leaf elongation are mediated by the blue-UV light receptor(s) because phytochrome photoequilibrium for each treatment were nearly identical.
Genome sequencing and analyses of the postharvest fungus Penicillium expansum R21
USDA-ARS?s Scientific Manuscript database
Blue mold is the vernacular name of a common postharvest disease of stored apples, pears and quince that is caused by several common species of Penicillium. This study reports the draft genome sequence of Penicillium expansum strain R21, a strain isolated from a Red Delicious apple in 2011 in Pennsy...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meier-Kolthoff, Jan P.; Lu, Megan; Huntemann, Marcel
Saccharomonospora cyanea Runmao et al. 1988 is a member of the genus Saccharomonospora in the family Pseudonocardiaceae that is moderately well characterized at the genome level thus far. Members of the genus Saccharomonospora are of interest because they originate from diverse habitats, such as soil, leaf litter, manure, compost, surface of peat, moist, over-heated grain, and ocean sediment, where they probably play a role in the primary degradation of plant material by attacking hemicellulose. Species of the genus Saccharomonospora are usually Gram-positive, non-acid fast, and are classified among the actinomycetes. S. cyanea is characterized by a dark blue (= cyanmore » blue) aerial mycelium. After S. viridis, S. azurea, and S. marina, S. cyanea is only the fourth member in the genus for which a completely sequenced (non-contiguous finished draft status) type strain genome will be published. Here we describe the features of this organism, together with the draft genome sequence, and annotation. The 5,408,301 bp long chromosome with its 5,139 protein-coding and 57 RNA genes was sequenced as part of the DOE funded Community Sequencing Program (CSP) 2010 at the Joint Genome Institute (JGI).« less
Double muscling in cattle due to mutations in the myostatin gene
McPherron, Alexandra C.; Lee, Se-Jin
1997-01-01
Myostatin (GDF-8) is a member of the transforming growth factor β superfamily of secreted growth and differentiation factors that is essential for proper regulation of skeletal muscle mass in mice. Here we report the myostatin sequences of nine other vertebrate species and the identification of mutations in the coding sequence of bovine myostatin in two breeds of double-muscled cattle, Belgian Blue and Piedmontese, which are known to have an increase in muscle mass relative to conventional cattle. The Belgian Blue myostatin sequence contains an 11-nucleotide deletion in the third exon which causes a frameshift that eliminates virtually all of the mature, active region of the molecule. The Piedmontese myostatin sequence contains a missense mutation in exon 3, resulting in a substitution of tyrosine for an invariant cysteine in the mature region of the protein. The similarity in phenotypes of double-muscled cattle and myostatin null mice suggests that myostatin performs the same biological function in these two species and is a potentially useful target for genetic manipulation in other farm animals. PMID:9356471
Proteorhodopsin-bearing bacteria in Antarctic sea ice.
Koh, Eileen Y; Atamna-Ismaeel, Nof; Martin, Andrew; Cowie, Rebecca O M; Beja, Oded; Davy, Simon K; Maas, Elizabeth W; Ryan, Ken G
2010-09-01
Proteorhodopsins (PRs) are widespread bacterial integral membrane proteins that function as light-driven proton pumps. Antarctic sea ice supports a complex community of autotrophic algae, heterotrophic bacteria, viruses, and protists that are an important food source for higher trophic levels in ice-covered regions of the Southern Ocean. Here, we present the first report of PR-bearing bacteria, both dormant and active, in Antarctic sea ice from a series of sites in the Ross Sea using gene-specific primers. Positive PR sequences were generated from genomic DNA at all depths in sea ice, and these sequences aligned with the classes Alphaproteobacteria, Gammaproteobacteria, and Flavobacteria. The sequences showed some similarity to previously reported PR sequences, although most of the sequences were generally distinct. Positive PR sequences were also observed from cDNA reverse transcribed from RNA isolated from sea ice samples. This finding indicates that these sequences were generated from metabolically active cells and suggests that the PR gene is functional within sea ice. Both blue-absorbing and green-absorbing forms of PRs were detected, and only a limited number of blue-absorbing forms were found and were in the midsection of the sea ice profile in this study. Questions still remain regarding the protein's ecological functions, and ultimately, field experiments will be needed to establish the ecological and functional role of PRs in the sea ice ecosystem.
Zhou, Ning; Zhao, Chuntian
2013-01-01
L-amino acid oxidase (LAAO) is attracting increasing attention due to its important functions. Diverse detection methods with their own properties have been developed for characterization of LAAO. In the present study, a simple, rapid, sensitive, cost-effective and reproducible method for quantitative in-gel determination of LAAO activity based on the visualization of Prussian blue-forming reaction is described. Coupled with SDS-PAGE, this Prussian blue agar assay can be directly used to determine the numbers and approximate molecular weights of LAAO in one step, allowing straightforward application for purification and sequence identification of LAAO from diverse samples. PMID:23383337
DOE Office of Scientific and Technical Information (OSTI.GOV)
Smith, Myron A.; Shiao, Bernard; Bianchi, Luciana, E-mail: myronmeister@gmail.com, E-mail: shiao@stsci.edu, E-mail: bianchi@pha.jhu.edu
We report on intriguing photometric properties of Galactic stars observed in the Galaxy Evolution Explorer (GALEX) satellite's far-UV (FUV) and near-UV (NUV) bandpasses, as well as from the ground-based Sloan Digital Sky Survey (SDSS) and the Kepler Input Catalog. The first property is that the (FUV – NUV) color distribution of stars in the Kepler field consists of two well-separated peaks. A second and more perplexing property is that for stars with spectral types G or later the mean (FUV – NUV) color becomes much bluer, contrary to expectation. Investigating this tendency further, we found in two samples of mid-Fmore » through K type stars that 17%-22% of them exhibit FUV excesses relative to their NUV fluxes and spectral types. A correction for FUV incompleteness of the FUV magnitude-limited star sample brings this ratio to 14%-18%. Nearly the same fractions are also discovered among members of the Kepler Eclipsing Binary Catalog and in the published list of Kepler Objects of Interest. These UV-excess ('UVe') colors are confirmed by the negative UV continuum slopes in GALEX spectra of members of the population. The SDSS spectra of some UVe stars exhibit metallic line weakening, especially in the blue. This suggests an enhanced contribution of UV flux relative to photospheric flux of a solar-type single star. We consider the possibility that the UV excesses originate from various types of hot stars, including white dwarf DA and sdB stars, binaries, and strong chromosphere stars that are young or in active binaries. The space density of compact stars is too low to explain the observed frequency of the UVe stars. Our model atmosphere-derived simulations of colors for binaries with main-sequence pairs with a hot secondary demonstrate that the color loci conflict with the observed sequence. As a preferred alternative we are left with the active chromospheres explanation, whether in active close binaries or young single stars, despite the expected paucity of young, chromospherically active stars in the field. We also address a third perplexing color property, namely, the presence of a prominent island of 'UV red' stars surrounded by 'UV blue' stars in the diagnostic (NUV–g), (g – i) color diagram. We find that the subpopulation composing this island is mainly horizontal branch stars. These objects do not exhibit UV excesses and therefore have UV colors typical for their spectral types. This subpopulation appears 'red' in the UV only because the stars' colors are not pulled to the blue by the inclusion of UVe stars.« less
ERIC Educational Resources Information Center
Schlottmann, Anne; Ray, Elizabeth D.; Surian, Luca
2012-01-01
Two experiments (N=136) studied how 4- to 6-month-olds perceive a simple schematic event, seen as goal-directed action and reaction from 3 years of age. In our causal reaction event, a red square moved toward a blue square, stopping prior to contact. Blue began to move away before red stopped, so that both briefly moved simultaneously at a…
Blue whale vocalizations recorded around New Zealand: 1964-2013.
Miller, Brian S; Collins, Kym; Barlow, Jay; Calderan, Susannah; Leaper, Russell; McDonald, Mark; Ensor, Paul; Olson, Paula A; Olavarria, Carlos; Double, Michael C
2014-03-01
Previous underwater recordings made in New Zealand have identified a complex sequence of low frequency sounds that have been attributed to blue whales based on similarity to blue whale songs in other areas. Recordings of sounds with these characteristics were made opportunistically during the Southern Ocean Research Partnership's recent Antarctic Blue Whale Voyage. Detections of these sounds occurred all around the South Island of New Zealand during the voyage transits from Nelson, New Zealand to the Antarctic and return. By following acoustic bearings from directional sonobuoys, blue whales were visually detected and confirmed as the source of these sounds. These recordings, together with the historical recordings made northeast of New Zealand, indicate song types that persist over several decades and are indicative of the year-round presence of a population of blue whales that inhabits the waters around New Zealand. Measurements of the four-part vocalizations reveal that blue whale song in this region has changed slowly, but consistently over the past 50 years. The most intense units of these calls were detected as far south as 53°S, which represents a considerable range extension compared to the limited prior data on the spatial distribution of this population.
52. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...
52. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown DETAILS OF MAIN FLOOR ELEVATOR LOBBY - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA
Wisniewski, Michael; Fazio, Gennaro; Burchard, Erik; Gutierrez, Benjamin; Levin, Elena; Droby, Samir
2017-01-01
Blue mold caused by Penicillium expansum is the most important postharvest disease of apple worldwide and results in significant financial losses. There are no defined sources of resistance to blue mold in domesticated apple. However, resistance has been described in wild Malus sieversii accessions, including plant introduction (PI)613981. The objective of the present study was to identify the genetic loci controlling resistance to blue mold in this accession. We describe the first quantitative trait loci (QTL) reported in the Rosaceae tribe Maleae conditioning resistance to P. expansum on genetic linkage group 3 (qM-Pe3.1) and linkage group 10 (qM-Pe10.1). These loci were identified in a M.× domestica ‘Royal Gala’ X M. sieversii PI613981 family (GMAL4593) based on blue mold lesion diameter seven days post-inoculation in mature, wounded apple fruit inoculated with P. expansum. Phenotypic analyses were conducted in 169 progeny over a four year period. PI613981 was the source of the resistance allele for qM-Pe3.1, a QTL with a major effect on blue mold resistance, accounting for 27.5% of the experimental variability. The QTL mapped from 67.3 to 74 cM on linkage group 3 of the GMAL4593 genetic linkage map. qM-Pe10.1 mapped from 73.6 to 81.8 cM on linkage group 10. It had less of an effect on resistance, accounting for 14% of the experimental variation. ‘Royal Gala’ was the primary contributor to the resistance effect of this QTL. However, resistance-associated alleles in both parents appeared to contribute to the least square mean blue mold lesion diameter in an additive manner at qM-Pe10.1. A GMAL4593 genetic linkage map composed of simple sequence repeats and ‘Golden Delicious’ single nucleotide polymorphism markers was able to detect qM-Pe10.1, but failed to detect qM-Pe3.1. The subsequent addition of genotyping-by-sequencing markers to the linkage map provided better coverage of the PI613981 genome on linkage group 3 and facilitated discovery of qM-Pe3.1. A DNA test for qM-Pe3.1 has been developed and is currently being evaluated for its ability to predict blue mold resistance in progeny segregating for qM-Pe3.1. Due to the long juvenility of apple, the availability of a DNA test to screen for the presence of qM-Pe3.1 at the seedling stage will greatly improve efficiency of breeding apple for blue mold resistance. PMID:28257442
SF3B1 and BAP1 mutations in blue nevus-like melanoma.
Griewank, Klaus G; Müller, Hansgeorg; Jackett, Louise A; Emberger, Michael; Möller, Inga; van de Nes, Johannes Ap; Zimmer, Lisa; Livingstone, Elisabeth; Wiesner, Thomas; Scholz, Simone L; Cosgarea, Ioana; Sucker, Antje; Schimming, Tobias; Hillen, Uwe; Schilling, Bastian; Paschen, Annette; Reis, Henning; Mentzel, Thomas; Kutzner, Heinz; Rütten, Arno; Murali, Rajmohan; Scolyer, Richard A; Schadendorf, Dirk
2017-07-01
Blue nevi are melanocytic tumors originating in the cutaneous dermis. Malignant tumors may arise in association with or resembling blue nevi, so called 'blue nevus-like melanoma', which can metastasize and result in patient death. Identifying which tumors will behave in a clinically aggressive manner can be challenging. Identifying genetic alterations in such tumors may assist in their diagnosis and prognostication. Blue nevi are known to be genetically related to uveal melanomas (eg, both harboring GNAQ and GNA11 mutations). In this study, we analyzed a large cohort (n=301) of various morphologic variants of blue nevi and related tumors including tumors diagnosed as atypical blue nevi (n=21), and blue nevus-like melanoma (n=12), screening for all gene mutations known to occur in uveal melanoma. Similar to published reports, we found the majority of blue nevi harbored activating mutations in GNAQ (53%) or GNA11 (15%). In addition, rare CYSLTR2 (1%) and PLCB4 (1%) mutations were identified. EIF1AX, SF3B1, and BAP1 mutations were also detected, with BAP1 and SF3B1 R625 mutations being present only in clearly malignant tumors (17% (n=2) and 25% (n=3) of blue nevus-like melanoma, respectively). In sequencing data from a larger cohort of cutaneous melanomas, this genetic profile was also identified in tumors not originally diagnosed as blue nevus-like melanoma. Our findings suggest that the genetic profile of coexistent GNAQ or GNA11 mutations with BAP1 or SF3B1 mutations can aid the histopathological diagnosis of blue nevus-like melanoma and distinguish blue nevus-like melanoma from conventional epidermal-derived melanomas. Future studies will need to further elucidate the prognostic implications and appropriate clinical management for patients with tumors harboring these mutation profiles.
Dalirsefat, Seyed Benyamin; Dong, Xianggui; Deng, Xuemei
2015-08-01
In total, 246 individuals from 8 Chinese indigenous blue- and brown-shelled chicken populations (Yimeng Blue, Wulong Blue, Lindian Blue, Dongxiang Blue, Lushi Blue, Jingmen Blue, Dongxiang Brown, and Lushi Brown) were genotyped for 21 SNP markers from the SLCO1B3 gene to evaluate phylogenetic relationships. As a representative of nonblue-shelled breeds, White Leghorn was included in the study for reference. A high proportion of SNP polymorphism was observed in Chinese chicken populations, ranging from 89% in Jingmen Blue to 100% in most populations, with a mean of 95% across all populations. The White Leghorn breed showed the lowest polymorphism, accounting for 43% of total SNPs. The mean expected heterozygosity varied from 0.11 in Dongxiang Blue to 0.46 in Yimeng Blue. Analysis of molecular variation (AMOVA) for 2 groups of Chinese chickens based on eggshell color type revealed 52% within-group and 43% between-group variations of the total genetic variation. As expected, FST and Reynolds' genetic distance were greatest between White Leghorn and Chinese chicken populations, with average values of 0.40 and 0.55, respectively. The first and second principal coordinates explained approximately 92% of the total variation and supported the clustering of the populations according to their eggshell color type and historical origins. STRUCTURE analysis showed a considerable source of variation among populations for the clustering into blue-shelled and nonblue-shelled chicken populations. The low estimation of genetic differentiation (FST) between Chinese chicken populations is possibly due to a common historical origin and high gene flow. Remarkably similar population classifications were obtained with all methods used in the study. Aligning endogenous avian retroviral (EAV)-HP insertion sequences showed no difference among the blue-shelled chickens. © 2015 Poultry Science Association Inc.
Fabrication of a white electroluminescent device based on bilayered yellow and blue quantum dots
NASA Astrophysics Data System (ADS)
Kim, Jong-Hoon; Lee, Ki-Heon; Kang, Hee-Don; Park, Byoungnam; Hwang, Jun Yeon; Jang, Ho Seong; Do, Young Rag; Yang, Heesun
2015-03-01
Until now most work on colloidal quantum dot-light-emitting diodes (QLEDs) has been focused on the improvement of the electroluminescent (EL) performance of monochromatic devices, and multi-colored white QLEDs comprising more than one type of QD emitter have been rarely investigated. To demonstrate a white EL as a result of color mixing between blue and yellow, herein a unique combination of two dissimilar QDs of blue- CdZnS/ZnS plus a yellow-emitting Cu-In-S (CIS)/ZnS is used for the formation of the emitting layer (EML) of a multilayered QLED. First, the QLED consisting of a single EML randomly mixed with two QDs is fabricated, however, its EL is dominated by blue emission with the contribution of yellow emission substantially weaker. Thus, another EML configuration is devised in the form of a QD bilayer with two stacking sequences of CdZnS/ZnS//CIS/ZnS QD and vice versa. The QLED with the former stacking sequence shows an overwhelming contribution of blue EL, similar to the mixed QD EML-based device. Upon applying the oppositely stacked QD bilayer of CIS/ZnS//CdZnS/ZnS, however, a bicolored white EL can be successfully achieved by means of the effective extension of the radiative excitonic recombination zone throughout both QD EML regions. Such QD EML configuration-dependent EL results, which are discussed primarily using the proposed device energy level diagram, strongly suggest that the positional design of individual QD emitters is a critical factor for the realization of multicolored, white emissive devices.Until now most work on colloidal quantum dot-light-emitting diodes (QLEDs) has been focused on the improvement of the electroluminescent (EL) performance of monochromatic devices, and multi-colored white QLEDs comprising more than one type of QD emitter have been rarely investigated. To demonstrate a white EL as a result of color mixing between blue and yellow, herein a unique combination of two dissimilar QDs of blue- CdZnS/ZnS plus a yellow-emitting Cu-In-S (CIS)/ZnS is used for the formation of the emitting layer (EML) of a multilayered QLED. First, the QLED consisting of a single EML randomly mixed with two QDs is fabricated, however, its EL is dominated by blue emission with the contribution of yellow emission substantially weaker. Thus, another EML configuration is devised in the form of a QD bilayer with two stacking sequences of CdZnS/ZnS//CIS/ZnS QD and vice versa. The QLED with the former stacking sequence shows an overwhelming contribution of blue EL, similar to the mixed QD EML-based device. Upon applying the oppositely stacked QD bilayer of CIS/ZnS//CdZnS/ZnS, however, a bicolored white EL can be successfully achieved by means of the effective extension of the radiative excitonic recombination zone throughout both QD EML regions. Such QD EML configuration-dependent EL results, which are discussed primarily using the proposed device energy level diagram, strongly suggest that the positional design of individual QD emitters is a critical factor for the realization of multicolored, white emissive devices. Electronic supplementary information (ESI) available: Detailed description of synthesis of CdZnS/ZnS, CIS/ZnS QDs and ZnO NPs; TEM images of CdZnS/ZnS and CIS/ZnS QDs; voltage-dependent luminance (CE variations of blue CdZnS/ZnS and yellow CIS/ZnS monochromatic QLEDs; EL spectra and energy band diagram of bilayered QD EML-based QLED with a stacking sequence of CdZnS/ZnS//CIS/ZnS QD; normalized EL spectra of CIS/ZnS//CdZnS/ZnS QD-bilayered QLEDs; comparison of current density of monochromatic QLEDs and bicolored white QLEDs; and voltage-dependent luminance (CE variations of CIS/ZnS QLED fabricated through 150 °C-EML baking. See DOI: 10.1039/c5nr00426h
Fabrication of a white electroluminescent device based on bilayered yellow and blue quantum dots.
Kim, Jong-Hoon; Lee, Ki-Heon; Kang, Hee-Don; Park, Byoungnam; Hwang, Jun Yeon; Jang, Ho Seong; Do, Young Rag; Yang, Heesun
2015-03-12
Until now most work on colloidal quantum dot-light-emitting diodes (QLEDs) has been focused on the improvement of the electroluminescent (EL) performance of monochromatic devices, and multi-colored white QLEDs comprising more than one type of QD emitter have been rarely investigated. To demonstrate a white EL as a result of color mixing between blue and yellow, herein a unique combination of two dissimilar QDs of blue- CdZnS/ZnS plus a yellow-emitting Cu-In-S (CIS)/ZnS is used for the formation of the emitting layer (EML) of a multilayered QLED. First, the QLED consisting of a single EML randomly mixed with two QDs is fabricated, however, its EL is dominated by blue emission with the contribution of yellow emission substantially weaker. Thus, another EML configuration is devised in the form of a QD bilayer with two stacking sequences of CdZnS/ZnS//CIS/ZnS QD and vice versa. The QLED with the former stacking sequence shows an overwhelming contribution of blue EL, similar to the mixed QD EML-based device. Upon applying the oppositely stacked QD bilayer of CIS/ZnS//CdZnS/ZnS, however, a bicolored white EL can be successfully achieved by means of the effective extension of the radiative excitonic recombination zone throughout both QD EML regions. Such QD EML configuration-dependent EL results, which are discussed primarily using the proposed device energy level diagram, strongly suggest that the positional design of individual QD emitters is a critical factor for the realization of multicolored, white emissive devices.
Hershler, Robert; Liu, Hsiu-Ping; Simpson, Jeffrey S
2015-01-01
Newly obtained and previously published sequences of the cytochrome c oxidase subunit I (COI) gene were analyzed to examine the biogeographic assembly of the caenogastropod fauna (belonging to the families Assimineidae, Cochliopidae, and Hydrobiidae) of an isolated spring along the lower Colorado River in southern Nevada (Blue Point Spring). Based on available COI clock calibrations, the three lineages that comprise this fauna are 2.78-1.42 million years old, which is roughly coeval or slightly younger than the age of Blue Point Spring (inferred from local fossil spring deposits). Two of the lineages-endemic Pyrgulopsiscoloradensis and Assimineaaff.infima-are most closely related to snails in the Death Valley area (well to the west) and likely colonized Blue Point Spring by transport on birds. A single haplotype was detected in both of these snails, suggesting that they may have only recently colonized Blue Point Spring. The third lineage-endemic Tryoniainfernalis, newly described herein based on morphological and molecular evidence-is most closely related to a geographically proximal species in a lower Colorado River tributary (Tryoniaclathrata); the split between these taxa may be the product of vicariance (severance of a prior drainage connection) or a separate jump dispersal event. The considerable genetic diversity in Tryoniainfernalis (three haplotypes differing by 0.6% mean sequence divergence) suggests a possibly lengthy history of local differentiation. Our findings also identify Blue Point Spring as a new micro-hotspot of groundwater-dependent biodiversity in Nevada and will assist ongoing efforts to protect and conserve these imperiled ecosystems.
Biswas, Subhajit; Jackson, Philippa; Shannon, Rebecca; Dulwich, Katherine; Sukla, Soumi; Dixon, Ronald A
This molecular study is the first report, to the best of our knowledge, on identification of norovirus, NoV GII.4 Sydney 2012 variants, from blue mussels collected from UK coastal waters. Blue mussels (three pooled samples from twelve mussels) collected during the 2013 summer months from UK coastal sites were screened by RT-PCR assays. PCR products of RdRP gene for noroviruses were purified, sequenced and subjected to phylogenetic analysis. All the samples tested positive for NoVs. Sequencing revealed that the NoV partial RdRP gene sequences from two pooled samples clustered with the pandemic "GII.4 Sydney variants" whilst the other pooled sample clustered with the NoV GII.2 variants. This molecular study indicated mussel contamination with pathogenic NoVs even during mid-summer in UK coastal waters which posed potential risk of NoV outbreaks irrespective of season. As the detection of Sydney 2012 NoV from our preliminary study of natural coastal mussels interestingly corroborated with NoV outbreaks in nearby areas during the same period, it emphasizes the importance of environmental surveillance work for forecast of high risk zones of NoV outbreaks. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.
Draft genome sequence of Penicillium expansum (R19) that cause postharvest decay of apple fruit
USDA-ARS?s Scientific Manuscript database
Among the species that cause blue mold, isolates of P. expansum are the most prevalent and virulent species causing more than 50 percent of postharvest decay. We report the draft genome sequence of P. expansum (R19) in order to identify fungal virulence factors and to understand the mechanism of inf...
Analisis fotometrico del cumulo abierto NGC 6611
NASA Astrophysics Data System (ADS)
Suarez Nunez, Johanna
2007-08-01
Matlab programs were designed to apply differential aperture photometry. Two images were taken with a charge-couple device ( CCD ) in the visible V and blue filters, to calculate physical parameters (the flux( f ), the apparent magnitude ( m V ) and its reddening corrected value ( V 0 ), color index ( B- V ) and ( B-V ) 0 , the log of effective temperature (log T eff ), the absolute magnitude ( M V ), the bolometric magnitude ( M B ) & log(L [low *] /[Special characters omitted.] )) of each studied star pertaining to the open cluster NGC 6611. Upon obtaining the parameters, the color-magnitude diagram was graphed and by fitting to the main sequence, the distance modulus and thus the distance to the cluster was found. The stars were assumed to be at the same distance and born at approximately the same moment.
Multifrequency observations of symbiotic stars
NASA Technical Reports Server (NTRS)
Kenyon, Scott J.
1988-01-01
The discovery of symbiotic stars is described, and the results of multifrequency observations made during the past two decades are presented. Observational data identify symbiotic stars as long-period binary systems that can be divided into two basic physical classes: detached symbiotics containing a red giant (or a Mira variable), and semidetached symbiotics containing a lobe-filling red giant and a solar-type main sequence star. Three components are typically observed: (1) the cool giant component with an effective temperature of 2500-4000 K, which can be divided by the IR spectral classification into normal M giants (S-types) and heavily reddened Mira variables (D-types); (2) the hot companion displaying a bright blue continuum at UV wavelengths, which is sometimes also an X-ray source; and (3) a gaseous nebula enveloping the binary.
Holkar, Chandrakant R; Pandit, Aniruddha B; Pinjari, Dipak V
2014-12-01
In the present study, an attempt was made to evaluate the bacterial decolorisation of Reactive Blue 19 by an Enterobacter sp.F which was isolated from a mixed culture from anaerobic digester for biogas production. Phenotypic characterization and phylogenetic analysis based on DNA sequencing comparisons indicate that Enterobacter sp.F was 99.7% similar to Enterobacter cloacae ATCC13047. The kinetics of Reactive Blue 19 dye decolorisation by bacterium had been estimated. Effects of substrate concentration, oxygen, temperature, pH, glucose and glucose to microbe weight ratio on the rate of decolorisation were investigated to understand key factor that determines the performance of dye decolorisation. The maximum decolorisation efficiency of Reactive Blue 19 was 90% over period of 24 h for optimized parameter. To the best of our knowledge, this research study is the report where Enterobacter sp.F has been reported with about 90% decolorizing ability against anthraquinone based Reactive Blue 19 dye. Copyright © 2014 Elsevier Ltd. All rights reserved.
Direct Evidence of Intrinsic Blue Fluorescence from Oligomeric Interfaces of Human Serum Albumin.
Bhattacharya, Arpan; Bhowmik, Soumitra; Singh, Amit K; Kodgire, Prashant; Das, Apurba K; Mukherjee, Tushar Kanti
2017-10-10
The molecular origin behind the concentration-dependent intrinsic blue fluorescence of human serum albumin (HSA) is not known yet. This unusual blue fluorescence is believed to be a characteristic feature of amyloid-like fibrils of protein/peptide and originates due to the delocalization of peptide bond electrons through the extended hydrogen bond networks of cross-β-sheet structure. Herein, by combining the results of spectroscopy, size exclusion chromatography, native gel electrophoresis, and confocal microscopy, we have shown that the intrinsic blue fluorescence of HSA exclusively originates from oligomeric interfaces devoid of any amyloid-like fibrillar structure. Our study suggests that this low energy fluorescence band is not due to any particular residue/sequence, but rather it is a common feature of self-assembled peptide bonds. The present findings of intrinsic blue fluorescence from oligomeric interfaces pave the way for future applications of this unique visual phenomenon for early stage detection of various protein aggregation related human diseases.
Reduction of molybdate to molybdenum blue by Klebsiella sp. strain hkeem.
Lim, H K; Syed, M A; Shukor, M Y
2012-06-01
A novel molybdate-reducing bacterium, tentatively identified as Klebsiella sp. strain hkeem and based on partial 16s rDNA gene sequencing and phylogenetic analysis, has been isolated. Strain hkeem produced 3 times more molybdenum blue than Serratia sp. strain Dr.Y8; the most potent Mo-reducing bacterium isolated to date. Molybdate was optimally reduced to molybdenum blue using 4.5 mM phosphate, 80 mM molybdate and using 1% (w/v) fructose as a carbon source. Molybdate reduction was optimum at 30 °C and at pH 7.3. The molybdenum blue produced from cellular reduction exhibited absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. Inhibitors of electron transport system such as antimycin A, rotenone, sodium azide, and potassium cyanide did not inhibit the molybdenum-reducing enzyme. Mercury, silver, and copper at 1 ppm inhibited molybdenum blue formation in whole cells of strain hkeem. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Behavioral Context of Call Production by Eastern North Pacific Blue Whales
2007-01-25
pairs occurring in a repeated song sequence; B calls from a different blue whale are also evident; spectrogram parameters: fast Fourier transform (FFT...Acoustic data were viewed in spectrogram form ( fast Fourier transform [FFT] length 1 s, 80% overlap, Hanning window) to de- termine the presence of calls...dura- tion to song A and B units (Table 2), but the intermit - tent timing clearly distinguishes them from song. Whales producing singular calls were
Automatic Cloud Classification from Multi-Spectral Satellite Data Over Oceanic Regions
1992-01-14
parameters the first two colors used are, blue for low values and dark green for high parameter values. If a third class is identified, the intermediate...intermediate yellow and high dark green classes. The color sequence blue-yellow-light green- dark green, then characterizes the low to high parameter value...to light green then to dark green correspond to superpixels of increasing (from low to high) variability in their altitude, (see Table V.3). When the
Galaxy Zoo: Major Galaxy Mergers Are Not a Significant Quenching Pathway
NASA Astrophysics Data System (ADS)
Weigel, Anna K.; Schawinski, Kevin; Caplar, Neven; Carpineti, Alfredo; Hart, Ross E.; Kaviraj, Sugata; Keel, William C.; Kruk, Sandor J.; Lintott, Chris J.; Nichol, Robert C.; Simmons, Brooke D.; Smethurst, Rebecca J.
2017-08-01
We use stellar mass functions to study the properties and the significance of quenching through major galaxy mergers. In addition to SDSS DR7 and Galaxy Zoo 1 data, we use samples of visually selected major galaxy mergers and post-merger galaxies. We determine the stellar mass functions of the stages that we would expect major-merger-quenched galaxies to pass through on their way from the blue cloud to the red sequence: (1) major merger, (2) post-merger, (3) blue early type, (4) green early type, and (5) red early type. Based on their similar mass function shapes, we conclude that major mergers are likely to form an evolutionary sequence from star formation to quiescence via quenching. Relative to all blue galaxies, the major-merger fraction increases as a function of stellar mass. Major-merger quenching is inconsistent with the mass and environment quenching model. At z˜ 0, major-merger-quenched galaxies are unlikely to constitute the majority of galaxies that transition through the green valley. Furthermore, between z˜ 0-0.5, major-merger-quenched galaxies account for 1%-5% of all quenched galaxies at a given stellar mass. Major galaxy mergers are therefore not a significant quenching pathway, neither at z˜ 0 nor within the last 5 Gyr. The majority of red galaxies must have been quenched through an alternative quenching mechanism that causes a slow blue to red evolution. .
Identification of Paracoccidioides brasiliensis by gold nanoprobes
NASA Astrophysics Data System (ADS)
Martins, Jaciara F. S.; Castilho, Maiara L.; Cardoso, Maria A. G.; Carreiro, Andrea P.; Martin, Airton A.; Raniero, Leandro
2012-01-01
Paracoccidioides brasiliensis (P. brasiliensis) is a thermal dimorphic fungus and causal agent of paracoccidioidomycosis. Epidemiological data shows that it is mainly concentrated in Central and South America countries, with most registered cases in Colombia, Brazil, and Venezuela. The histopathological similarity with others fungal infection makes the diagnosis of P. brasiliensis more complicated. Therefore, the aim of this work was to find a positive and negative test for P. brasiliensis using gold nanoprobes as a new tool for P. brasiliensis detection. Gold nanoparticles were synthesized by reduction of gold chloride with sodium citrate. The results of this procedure is a wine-red solution with a maximum absorption in the range of ~520-530nm. A specific P. brasiliensis sequence of oligonucleotide was bonded to the nanoparticles, which maintained the wine-red color. The color changes from red to blue for negative diagnostic and is unchanged for a positive test. The H-bond interaction of DNA with the complementary DNA keeps strands together and forms double helical structure, maintaining the colloid stability. However, for non-complimentary DNA sequence the nanoprobes merge into a cluster, changing the light absorption.
Yin, Guohua; Zhang, Yuliang; Pennerman, Kayla K.; Wu, Guangxi; Hua, Sui Sheng T.; Yu, Jiujiang; Jurick, Wayne M.; Guo, Anping; Bennett, Joan W.
2017-01-01
Penicillium is a large genus of common molds with over 400 described species; however, identification of individual species is difficult, including for those species that cause postharvest rots. In this study, blue rot fungi from stored apples and pears were isolated from a variety of hosts, locations, and years. Based on morphological and cultural characteristics and partial amplification of the β-tubulin locus, the isolates were provisionally identified as several different species of Penicillium. These isolates were investigated further using a suite of molecular DNA markers and compared to sequences of the ex-type for cognate species in GenBank, and were identified as P. expansum (3 isolates), P. solitum (3 isolates), P. carneum (1 isolate), and P. paneum (1 isolate). Three of the markers we used (ITS, internal transcribed spacer rDNA sequence; benA, β-tubulin; CaM, calmodulin) were suitable for distinguishing most of our isolates from one another at the species level. In contrast, we were unable to amplify RPB2 sequences from four of the isolates. Comparison of our sequences with cognate sequences in GenBank from isolates with the same species names did not always give coherent data, reinforcing earlier studies that have shown large intraspecific variability in many Penicillium species, as well as possible errors in some sequence data deposited in GenBank. PMID:29371531
The Hottest Horizontal-Branch Stars in Omega Centauri: Late Hot Flasher vs. Helium Enrichment
NASA Technical Reports Server (NTRS)
Moehler, S.; Dreizler, S.; Lanz, T.; Bono, G.; Sweigart, A V.; Calamida, A.; Monelli, M.; Nonino, M.
2007-01-01
UV observations of some massive globular clusters uncovered a significant population of very hot stars below the hot end of the horizontal branch (HB), the so-called blue hook stars. This feature might be explained either by the late hot flasher scenario here stars experience the helium flash while on the white dwarf cooling curve or by the helium-rich sub-population recently postulated to exist in some clusters. Spectroscopic analyses of blue hook stars in omega Cen and NGC 2808 support the late hot flasher scenario, but the stars contain much less helium than expected and the predicted C, N enrichment could not be verified from existing data. We want to determine effective temperatures, surface gravities and abundances of He, C, N in blue hook and canonical extreme horizontal branch (EHB) star candidates. Moderately high resolution spectra of stars at the hot end of the blue horizontal branch in the globular cluster omega Cen were analysed for atmospheric parameters (T(sub eff), log g) and abundances using LTE and Non-LTE model atmospheres. In the temperature range 30,000 K to 50,000 K we find that 37% of our stars are helium-poor (log nHe/nH less than -2), 49% have solar helium abundance within a factor of 3 (-1.5 less than or equal to log nHe/nH less than or equal to -0.5) and 14% are helium rich (log nHe/nH greater than -0.4). We also find carbon enrichment in step with helium enrichment, with a maximum carbon enrichment of 3% by mass. At least 30% of the hottest HB stars in omega Centauri show helium abundances well above the predictions from the helium enrichment scenario (Y = 0.42 corresponding to log nHe/nH approximately equal to -0.74). In addition the most helium-rich stars show strong carbon enrichment as predicted by the late hot flasher scenario. We conclude that the helium-rich HB stars in omega Cen cannot be explained solely by the helium-enrichment scenario invoked to explain the blue main sequence.
The evolution of blue-greens and the origins of chloroplasts
NASA Technical Reports Server (NTRS)
Schwartz, R. M.; Dayhoff, M. O.
1981-01-01
All of the available molecular data support the theory that the chloroplasts of eukaryote cells were originally free-living blue-greens. Of great interest is what the relationships are between contemporary types of blue-greens and eukaryote chloroplasts and whether the chloroplasts of the various eukaryotes are the result of one or more than one symbiosis. By combining information from phylogenetic trees based on cytochrome c6 and 2Fe-2S ferredoxin sequences, it is shown that the chloroplasts of a number of eukaryote algae as well as the protist Euglena are polyphyletic; the chloroplasts of green algae and the higher plants may be the result of a single symbiosis.
ACS Imaging of beta Pic: Searching for the origin of rings and asymmetry in planetesimal disks
NASA Astrophysics Data System (ADS)
Kalas, Paul
2003-07-01
The emerging picture for planetesimal disks around main sequence stars is that their radial and azimuthal symmetries are significantly deformed by the dynamical effects of either planets interior to the disk, or stellar objects exterior to the disk. The cause of these structures, such as the 50 AU cutoff of our Kuiper Belt, remains mysterious. Structure in the beta Pic planetesimal disk could be due to dynamics controlled by an extrasolar planet, or by the tidal influence of a more massive object exterior to the disk. The hypothesis of an extrasolar planet causing the vertical deformation in the disk predicts a blue color to the disk perpendicular to the disk midplane. The hypothesis that a stellar perturber deforms the disk predicts a globally uniform color and the existence of ring-like structure beyond 800 AU radius. We propose to obtain deep, multi-color images of the beta Pic disk ansae in the region 15"-220" {200-4000 AU} radius with the ACS WFC. The unparalleled stability of the HST PSF means that these data are uniquely capable of delivering the color sensitivity that can distinguish between the two theories of beta Pic's disk structure. Ascertaining the cause of such structure provide a meaningful context for understanding the dynamical history of our early solar system, as well as other planetesimal systems imaged around main sequence stars.
Ozasa, Kazunari; Won, June; Song, Simon; Tamaki, Shun; Ishikawa, Takahiro; Maeda, Mizuo
2017-01-01
The adaptation to a strong light is one of the essential characteristics of green algae, yet lacking relatively the information about the photophobic responses of Eukaryotic microalgae. We investigated the photophobic step-up responses of Euglena gracilis over a time course of several hours with alternated repetition of blue-light pulse illumination and spatially patterned blue-light illumination. Four distinctive photophobic motions in response to strong blue light were identified in a trace image analysis, namely on-site rotation, running and tumbling, continuous circular swimming, and unaffected straightforward swimming. The cells cultured in autotrophic conditions under weak light showed mainly the on-site rotation response at the beginning of blue-light illumination, but they acquired more blue-light tolerant responses of running and tumbling, circular swimming, or straightforward swimming. The efficiency of escaping from a blue-light illuminated area improved markedly with the development of these photophobic motions. Time constant of 3.0 h was deduced for the evolution of photophobic responses of E. gracilis. The nutrient-rich metabolic status of the cells resulting from photosynthesis during the experiments, i.e., the accumulation of photosynthesized nutrient products in balance between formation and consumption, was the main factor responsible for the development of photophobic responses. The reduction-oxidation status in and around E. gracilis cells did not affect their photophobic responses significantly, unlike the case of photophobic responses and phototaxis of Chlamydomonas reinhardtii cells. This study shows that the evolution of photophobic motion type of E. gracilis is dominated mainly by the nutrient metabolic status of the cells. The fact suggests that the nutrient-rich cells have a higher threshold for switching the flagellar motion from straightforward swimming to rotation under a strong light. PMID:28234984
VizieR Online Data Catalog: Spectroscopically Identified Hot Subdwarf Stars (Kilkenny+ 1988)
NASA Astrophysics Data System (ADS)
Kilkenny, D.; Heber, U.; Drilling, J. S.
1996-05-01
Prior to 1986 there were around 200 spectroscopically classified hot subdwarf stars. The Palomar-Green survey (Green et al., 1986ApJS...61..305G) detected over 900 hot subdwarfs, mostly in the North Galactic Cap and mostly previously unknown objects; the Kitt-Peak_Downes survey found another 60 near the Galactic Plane (Downes, 1986ApJS...61..569D). These form the basis of the present catalog but new subdwarfs are continually being found by spectroscopic surveys of photographically discovered faint blue star samples; examples are the work of Wegner and his co-workers on the Kiso survey (Wegner et al., 1985AJ.....90.1511W, 1986AJ.....91..139W, 1987AJ.....94.1271W) and of Kilkenny and Muller (1987) on southern discoveries by Luyten and collaborators (e.g. Haro and Luyten, 1962, Cat. III/74; Luyten and Anderson, 1958, 1959, 1967, "A Search for Faint Blue Stars"). Only stars for which a spectroscopic classification exists have been included. There is a significant probability that stars with only photometric classifications can be normal high-latitude B stars, white dwarfs or cataclysmic variable, for example. Hot subdwarfs in binary systems have been included but not planetary nebulae nuclei classified 'sd' since the latter have been catalogued elsewhere. Although there is not a universally accepted classification scheme for hot subdwarfs, it is fairly clear that the main criterion is a surface gravity higher than that of hot main sequence stars but less than that of hot white dwarfs. Also, hot subdwarf stars typically show helium abundance anomalies. (3 data files).
Chemical and Kinematical Properties of Blue Straggler Stars and Horizontal Branch Stars in NGC 6397
NASA Astrophysics Data System (ADS)
Lovisi, L.; Mucciarelli, A.; Lanzoni, B.; Ferraro, F. R.; Gratton, R.; Dalessandro, E.; Contreras Ramos, R.
2012-08-01
We used three sets of high-resolution spectra acquired with the multifiber facility FLAMES at the Very Large Telescope of the European Southern Observatory to investigate the chemical and kinematical properties of a sample of 42 horizontal branch (HB) stars, 18 blue straggler stars (BSSs), and 86 main-sequence (MS) turnoff (TO) and sub-giant branch stars in the nearby globular cluster NGC 6397. We measured rotational velocities and Fe, O, and Mg abundances. All of the unevolved stars in our sample have low rotational velocites (vsin i < 10 km s-1), while the HB stars and BSSs show a broad distribution, with values ranging from 0 to ~70 km s-1. For HB stars with T < 10,500 K there is a clear temperature-oxygen anticorrelation that can be understood if the star position along the HB is mainly determined by the He content. The hottest BSSs and HB stars (with temperatures T > 8200 K and T > 10,500 K, respectively) also show significant deviations in their iron abundance with respect to the cluster metallicity (as traced by the unevolved stars, [Fe/H] = -2.12). While similar chemical patterns have already been observed in other hot HB stars, this is the first evidence ever collected for BSSs. We interpret these abundance anomalies as due to the metal radiative levitation, occurring in stars with shallow or no convective envelopes. Based on FLAMES observations collected at the European Southern Observatory, proposal numbers 073.D-0058, 075.D-0125, and 081.D-0356.
Serezhnikova, N B; Pogodina, L S; Lipina, T V; Trofimova, N N; Gurieva, T S; Zak, P P
2017-07-01
The effect of everyday blue light (λ = 440-460 nm) on mitochondria of the retinal pigment epithelium of different age groups of Japanese quail was studied using electron microscopy, morphometric methods, and biochemical analysis. We have found a significant increase in the number of mitochondria, including those modified, mainly in young birds. In addition, cell metabolic activity increased in response to blue lighting. These changes are assumed to reflect an adaptive response of mitochondria aimed at neutralizing the phototoxic effect of blue light caused by accumulation of lipofuscin granules.
Gao, Bo; Shao, Qin; Choudhry, Hani; Marcus, Victoria; Dong, Kung; Ragoussis, Jiannis; Gao, Zu-Hua
2016-09-01
Approximately 9% of cancer-related deaths are caused by colorectal cancer (CRC). CRC patients are prone to liver metastasis, which is the most important cause for the high CRC mortality rate. Understanding the molecular mechanism of CRC liver metastasis could help us to find novel targets for the effective treatment of this deadly disease. Using weighted gene co-expression network analysis on the sequencing data of CRC with and with metastasis, we identified 5 colorectal cancer liver metastasis related modules which were labeled as brown, blue, grey, yellow and turquoise. In the brown module, which represents the metastatic tumor in the liver, gene ontology (GO) analysis revealed functions including the G-protein coupled receptor protein signaling pathway, epithelial cell differentiation and cell surface receptor linked signal transduction. In the blue module, which represents the primary CRC that has metastasized, GO analysis showed that the genes were mainly enriched in GO terms including G-protein coupled receptor protein signaling pathway, cell surface receptor linked signal transduction, and negative regulation of cell differentiation. In the yellow and turquoise modules, which represent the primary non-metastatic CRC, 13 downregulated CRC liver metastasis-related candidate miRNAs were identified (e.g. hsa-miR-204, hsa-miR-455, etc.). Furthermore, analyzing the DrugBank database and mining the literature identified 25 and 12 candidate drugs that could potentially block the metastatic processes of the primary tumor and inhibit the progression of metastatic tumors in the liver, respectively. Data generated from this study not only furthers our understanding of the genetic alterations that drive the metastatic process, but also guides the development of molecular-targeted therapy of colorectal cancer liver metastasis.
NASA Astrophysics Data System (ADS)
Milone, A. P.; Marino, A. F.; Di Criscienzo, M.; D'Antona, F.; Bedin, L. R.; Da Costa, G.; Piotto, G.; Tailo, M.; Dotter, A.; Angeloni, R.; Anderson, J.; Jerjen, H.; Li, C.; Dupree, A.; Granata, V.; Lagioia, E. P.; Mackey, A. D.; Nardiello, D.; Vesperini, E.
2018-06-01
The split main sequences (MSs) and extended MS turnoffs (eMSTOs) detected in a few young clusters have demonstrated that these stellar systems host multiple populations differing in a number of properties such as rotation and, possibly, age. We analyse Hubble Space Telescope photometry for 13 clusters with ages between ˜40 and ˜1000 Myr and of different masses. Our goal is to investigate for the first time the occurrence of multiple populations in a large sample of young clusters. We find that all the clusters exhibit the eMSTO phenomenon and that MS stars more massive than ˜1.6 M_{⊙} define a blue and a red MS, with the latter hosting the majority of MS stars. The comparison between the observations and isochrones suggests that the blue MSs are made of slow-rotating stars, while the red MSs host stars with rotational velocities close to the breakup value. About half of the bright MS stars in the youngest clusters are H α emitters. These Be stars populate the red MS and the reddest part of the eMSTO, thus supporting the idea that the red MS is made of fast rotators. We conclude that the split MS and the eMSTO are a common feature of young clusters in both Magellanic Clouds. The phenomena of a split MS and an eMSTO occur for stars that are more massive than a specific threshold, which is independent of the host-cluster mass. As a by-product, we report the serendipitous discovery of a young Small Magellanic Cloud cluster, GALFOR 1.
Smithsonian Ocean Portal | Find Your Blue
Skip to main content Menu Search form Search Search Find Your Blue Smithsonian National Museum of Vents & Volcanoes Temperature & Chemistry Ice The Ocean Through Time Ancient Seas Fossils Temperature & Chemistry Ice The Ocean Through Time Ancient Seas Fossils Evolution Shifting Baselines
Leduc, R G; Archer, F I; Lang, A R; Martien, K K; Hancock-Hanser, B; Torres-Florez, J P; Hucke-Gaete, R; Rosenbaum, H C; van Waerebeek, K; Brownell, R L; Taylor, B L
2017-02-01
Many aspects of blue whale biology are poorly understood. Some of the gaps in our knowledge, such as those regarding their basic taxonomy and seasonal movements, directly affect our ability to monitor and manage blue whale populations. As a step towards filling in some of these gaps, microsatellite and mtDNA sequence analyses were conducted on blue whale samples from the Southern Hemisphere, the eastern tropical Pacific (ETP) and the northeast Pacific. The results indicate that the ETP is differentially used by blue whales from the northern and southern eastern Pacific, with the former showing stronger affinity to the region off Central America known as the Costa Rican Dome, and the latter favouring the waters of Peru and Ecuador. Although the pattern of genetic variation throughout the Southern Hemisphere is compatible with the recently proposed subspecies status of Chilean blue whales, some discrepancies remain between catch lengths and lengths from aerial photography, and not all blue whales in Chilean waters can be assumed to be of this type. Also, the range of the proposed Chilean subspecies, which extends to the Galapagos region of the ETP, at least seasonally, perhaps should include the Costa Rican Dome and the eastern North Pacific as well. © 2016 John Wiley & Sons Ltd.
NASA Technical Reports Server (NTRS)
2000-01-01
This is the original Voyager 'Blue Movie' (so named because it was built from Blue filter images). It records the approach of Voyager 1 during a period of over 60 Jupiter days. Notice the difference in speed and direction of the various zones of the atmosphere. The interaction of the atmospheric clouds and storms shows how dynamic the Jovian atmosphere is.As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 66 images taken once every Jupiter rotation period (about 10 hours). This time-lapse movie uses images taken every time Jupiter longitude 68W passed under the spacecraft. These images were acquired in the Blue filter from Jan. 6 to Feb. 3 1979. The spacecraft flew from 58 million kilometers to 31 million kilometers from Jupiter during that time.This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.Corrêa, R L; Silva, T F; Simões-Araújo, J L; Barroso, P A V; Vidal, M S; Vaslin, M F S
2005-07-01
Cotton blue disease is an aphid-transmitted cotton disease described in Brazil in 1962 as Vein Mosaic "var. Ribeirão Bonito". At present it causes economically important losses in cotton crops if control measures are not implemented. The observed symptoms and mode of transmission have prompted researchers to speculate that cotton blue disease could be attributed to a member of the family Luteoviridae, but there was no molecular evidence supporting this hypothesis. We have amplified part of the genome of a virus associated with this disease using degenerate primers for members of the family Luteoviridae. Sequence analysis of the entire capsid and a partial RdRp revealed a virus probably belonging to the genus Polerovirus. Based on our results we propose that cotton blue disease is associated with a virus with the putative name Cotton leafroll dwarf virus (CLRDV).
Double blue straggler sequences in globular clusters: The case of NGC 362
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dalessandro, E.; Ferraro, F. R.; Massari, D.
2013-12-01
We used high-quality images acquired with the Wide Field Camera 3 on board the Hubble Space Telescope to probe the blue straggler star (BSS) population of the galactic globular cluster NGC 362. We have found two distinct sequences of BSSs: this is the second case, after M30, where such a feature has been observed. Indeed, the BSS location, their extension in magnitude and color, and their radial distribution within the cluster nicely resemble those observed in M30, thus suggesting that the same interpretative scenario can be applied: the red BSS sub-population is generated by mass-transfer binaries, the blue one bymore » collisions. The discovery of four new W UMa stars, three of which lie along the red BSS sequence, further supports this scenario. We also found that the inner portion of the density profile deviates from a King model and is well reproduced by either a mild power law (α ∼ –0.2) or a double King profile. This feature supports the hypothesis that the cluster is currently undergoing the core-collapse phase. Moreover, the BSS radial distribution shows a central peak and monotonically decreases outward without any evidence of an external rising branch. This evidence is a further indication of the advanced dynamical age of NGC 362; in fact, together with M30, NGC 362 belongs to the family of dynamically old clusters (Family III) in the 'dynamical clock' classification proposed by Ferraro et al. The observational evidence presented here strengthens the possible connection between the existence of a double BSS sequence and a quite advanced dynamical status of the parent cluster.« less
Seafood delicacy makes great adhesive
Idaho National Laboratory - Frank Roberto, Heather Silverman
2017-12-09
Technology from Mother Nature is often hard to beat, so Idaho National Laboratory scientistsgenetically analyzed the adhesive proteins produced by blue mussels, a seafood delicacy. Afterobtaining full-length DNA sequences encoding these proteins, reprod
Limpanuparb, Taweetham; Roongruangsree, Pakpong; Areekul, Cherprang
2017-11-01
The blue bottle experiment is a collective term for autoxidation reactions catalysed by redox indicators. The reactions are characterized by their repeatable cycle of colour changes when shaken/left to stand and intricate chemical pattern formation. The blue bottle experiment is studied based on calculated solution-phase half-cell reduction potential of related reactions. Our investigation confirms that the reaction in various versions of the blue bottle experiment published to date is mainly the oxidation of an acyloin to a 1,2-dicarbonyl structure. In the light of the calculations, we also propose new non-acyloin reducing agents for the experiment. These results can help guide future experimental studies on the blue bottle experiment.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-22
... DEPARTMENT OF TRANSPORTATION Maritime Administration [Docket No. MARAD-2013-0129] Requested Administrative Waiver of the Coastwise Trade Laws: Vessel BLUE MOON; Invitation for Public Comments AGENCY... MOON is: Intended Commercial Use of Vessel: ``Bareboat Charter'' Geographic Region: ``Maine, Maryland...
Stervander, Martin; Illera, Juan Carlos; Kvist, Laura; Barbosa, Pedro; Keehnen, Naomi P; Pruisscher, Peter; Bensch, Staffan; Hansson, Bengt
2015-05-01
Isolated islands and their often unique biota continue to play key roles for understanding the importance of drift, genetic variation and adaptation in the process of population differentiation and speciation. One island system that has inspired and intrigued evolutionary biologists is the blue tit complex (Cyanistes spp.) in Europe and Africa, in particular the complex evolutionary history of the multiple genetically distinct taxa of the Canary Islands. Understanding Afrocanarian colonization events is of particular importance because of recent unconventional suggestions that these island populations acted as source of the widespread population in mainland Africa. We investigated the relationship between mainland and island blue tits using a combination of Sanger sequencing at a population level (20 loci; 12 500 nucleotides) and next-generation sequencing of single population representatives (>3 200 000 nucleotides), analysed in coalescence and phylogenetic frameworks. We found (i) that Afrocanarian blue tits are monophyletic and represent four major clades, (ii) that the blue tit complex has a continental origin and that the Canary Islands were colonized three times, (iii) that all island populations have low genetic variation, indicating low long-term effective population sizes and (iv) that populations on La Palma and in Libya represent relicts of an ancestral North African population. Further, demographic reconstructions revealed (v) that the Canary Islands, conforming to traditional views, hold sink populations, which have not served as source for back colonization of the African mainland. Our study demonstrates the importance of complete taxon sampling and an extensive multimarker study design to obtain robust phylogeographical inferences. © 2015 John Wiley & Sons Ltd.
Mutations in GNA11 in Uveal Melanoma
Van Raamsdonk, Catherine D.; Griewank, Klaus G.; Crosby, Michelle B.; Garrido, Maria C.; Vemula, Swapna; Wiesner, Thomas; Obenauf, Anna C.; Wackernagel, Werner; Green, Gary; Bouvier, Nancy; Sozen, M. Mert; Baimukanova, Gail; Roy, Ritu; Heguy, Adriana; Dolgalev, Igor; Khanin, Raya; Busam, Klaus; Speicher, Michael R.; O’Brien, Joan; Bastian, Boris C.
2011-01-01
BACKGROUND Uveal melanoma is the most common intraocular cancer. There are no effective therapies for metastatic disease. Mutations in GNAQ, the gene encoding an alpha subunit of heterotrimeric G proteins, are found in 40% of uveal melanomas. METHODS We sequenced exon 5 of GNAQ and GNA11, a paralogue of GNAQ, in 713 melanocytic neoplasms of different types (186 uveal melanomas, 139 blue nevi, 106 other nevi, and 282 other melanomas). We sequenced exon 4 of GNAQ and GNA11 in 453 of these samples and in all coding exons of GNAQ and GNA11 in 97 uveal melanomas and 45 blue nevi. RESULTS We found somatic mutations in exon 5 (affecting Q209) and in exon 4 (affecting R183) in both GNA11 and GNAQ, in a mutually exclusive pattern. Mutations affecting Q209 in GNA11 were present in 7% of blue nevi, 32% of primary uveal melanomas, and 57% of uveal melanoma metastases. In contrast, we observed Q209 mutations in GNAQ in 55% of blue nevi, 45% of uveal melanomas, and 22% of uveal melanoma metastases. Mutations affecting R183 in either GNAQ or GNA11 were less prevalent (2% of blue nevi and 6% of uveal melanomas) than the Q209 mutations. Mutations in GNA11 induced spontaneously metastasizing tumors in a mouse model and activated the mitogen-activated protein kinase pathway. CONCLUSIONS Of the uveal melanomas we analyzed, 83% had somatic mutations in GNAQ or GNA11. Constitutive activation of the pathway involving these two genes appears to be a major contributor to the development of uveal melanoma. (Funded by the National Institutes of Health and others.) PMID:21083380
BARIUM SURFACE ABUNDANCES OF BLUE STRAGGLERS IN THE OPEN CLUSTER NGC 6819
DOE Office of Scientific and Technical Information (OSTI.GOV)
Milliman, Katelyn E.; Mathieu, Robert D.; Schuler, Simon C., E-mail: milliman@astro.wisc.edu
2015-09-15
We present a barium surface abundance of 12 blue stragglers (BSs) and 18 main-sequence (MS) stars in the intermediate-age open cluster NGC 6819 (2.5 Gyr) based on spectra obtained from the Hydra Multi-object Spectrograph on the WIYN 3.5 m telescope. For the MS stars we find [Fe/H] = +0.05 ± 0.04 and [Ba/Fe] = −0.01 ± 0.10. The majority of the BS stars are consistent with these values. We identify five BSs with significant barium enhancement. These stars most likely formed through mass transfer from an asymptotic giant branch star that polluted the surface of the BS with the nucleosynthesismore » products generated during thermal pulsations. This conclusion aligns with the results from the substantial work done on the BSs in old open cluster NGC 188 that identifies mass transfer as the dominant mechanism for BS formation in that open cluster. However, four of the BSs with enhanced barium show no radial-velocity evidence for a companion. The one star that is in a binary is a double-lined system, meaning the companion is not a white dwarf and not the remnant of a prior AGB star. In this paper we attempt to develop a consistent scenario to explain the origin of these five BSs.« less
Deep Imaging of Eridanus II and Its Lone Star Cluster
NASA Astrophysics Data System (ADS)
Crnojević, D.; Sand, D. J.; Zaritsky, D.; Spekkens, K.; Willman, B.; Hargis, J. R.
2016-06-01
We present deep imaging of the most distant dwarf discovered by the Dark Energy Survey, Eridanus II (Eri II). Our Magellan/Megacam stellar photometry reaches ˜3 mag deeper than previous work and allows us to confirm the presence of a stellar cluster whose position is consistent with Eri II’s center. This makes Eri II, at {M}V=-7.1, the least luminous galaxy known to host a (possibly central) cluster. The cluster is partially resolved, and at {M}V=-3.5 it accounts for ˜4% of Eri II’s luminosity. We derive updated structural parameters for Eri II, which has a half-light radius of ˜280 pc and is elongated (ɛ ˜ 0.48) at a measured distance of D ˜ 370 kpc. The color-magnitude diagram displays a blue, extended horizontal branch, as well as a less populated red horizontal branch. A central concentration of stars brighter than the old main-sequence turnoff hints at a possible intermediate-age (˜3 Gyr) population; alternatively, these sources could be blue straggler stars. A deep Green Bank Telescope observation of Eri II reveals no associated atomic gas. This paper includes data gathered with the 6.5 m Magellan Telescopes at Las Campanas Observatory, Chile.
Resolved stars in nearby galaxies: Ground-based photometry of M81
NASA Technical Reports Server (NTRS)
Madore, Barry F.; Freedman, Wendy L.; Lee, Myung G.
1993-01-01
Using the Canada-France-Hawaii Telescope (CFHT) we have obtained three closely spaced epochs of calibrated Blue Violet Red Infrared (BVRI) CCD imaging of two fields in M81, each known to contain a thirty-day Cepheid. Calibrated BVRI photometry of the brightest stars in these fields is presented. The slope of the luminosity function from the brightest 3-4 mag of the main-sequence blue plume is consistent with similar determinations of the apparent luminosity function in other resolved galaxies, thereby removing the one potential deviation from universality noted by Freedman in a photographic study of luminosity functions in nearby resolved galaxies. Under the assumption that the two Cepheids are representative, a reddening-law fit to the multiwavelength BVRI period-luminosity moduli give a true distance modulus of (m-M)sub 0 = 27.79 mag for M81, corresponding to a linear distance of 3.6 Mpc. An error analysis shows that the derived true distance modulus has a random error of +/- 0.28 mag (due to the photometric uncertainties in the BVRI data), with a systematic uncertainty of +/- 0.10 mag (accounting for the combined effects of unknown phasing of the data points, and the unknown positioning of these particular stars within the Cepheid instabiliy strip).
Sunset Sequence in Mars Gale Crater Animation
2015-05-08
NASA's Curiosity Mars rover recorded this sequence of views of the sun setting at the close of the mission's 956th Martian day, or sol (April 15, 2015), from the rover's location in Gale Crater. The four images shown in sequence here were taken over a span of 6 minutes, 51 seconds. This was the first sunset observed in color by Curiosity. The images come from the left-eye camera of the rover's Mast Camera (Mastcam). The color has been calibrated and white-balanced to remove camera artifacts. Mastcam sees color very similarly to what human eyes see, although it is actually a little less sensitive to blue than people are. Dust in the Martian atmosphere has fine particles that permit blue light to penetrate the atmosphere more efficiently than longer-wavelength colors. That causes the blue colors in the mixed light coming from the sun to stay closer to sun's part of the sky, compared to the wider scattering of yellow and red colors. The effect is most pronounced near sunset, when light from the sun passes through a longer path in the atmosphere than it does at mid-day. Malin Space Science Systems, San Diego, built and operates the rover's Mastcam. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover. http://photojournal.jpl.nasa.gov/catalog/PIA19401
Dunn, Robert A; Hernandez, Olga
2009-09-01
Low frequency northeastern Pacific blue whale calls were recorded near the northern East Pacific Rise (9 degrees N latitude) on 25 ocean-bottom-mounted hydrophones and three-component seismometers during a 5-day period (November 22-26, 1997). Call types A, B, C, and D were identified; the most common pattern being approximately 130-135 s repetitions of the AB sequence that, for any individual whale, persisted for hours. Up to eight individual blue whales were recorded near enough to the instruments to determine their locations and were tracked call-by-call using the B components of the calls and a Bayesian inversion procedure. For four of these eight whales, the entire call sequences and swim tracks were determined for 20-26-h periods; the other whales were tracked for much shorter periods. The eight whales moved into the area during a period of airgun activity conducted by the academic seismic ship R/V Maurice Ewing. The authors examined the whales' locations and call characteristics with respect to the periods of airgun activity. Although the data do not permit a thorough investigation of behavioral responses, no correlation in vocalization or movement with airgun activity was observed.
DOT National Transportation Integrated Search
1998-01-01
At its fortieth session, the UN/ECE Working Party on Inland Water Transport (SC.3) agreed to proceed with the drafting of the so-called "blue book" which would contain technical characteristics of European inland waterways and ports of international ...
NASA Technical Reports Server (NTRS)
Carney, B. W.; Janes, K. A.; Flower, P. J.
1985-01-01
A color-magnitude diagram has been obtained for the young SMC cluster NGC 330. The diagram shows a well-defined main sequence, a group of blue supergiants, a group of red supergiants between B-V = 1.2 m and 1.6 m about one magnitude fainter, and an empty Hertzsprung gap. The surrounding field is a composite of a very gold population resembling galactic globular clusters and a very young population. DDO and infrared photometry strongly suggest that the cluster is metal-poor, but a definitive measure could not be made because of calibration difficulties. The cluster's age is estimated at 12 million years, with the surrounding field about 50 percent older. The cluster will prove very useful in testing stellar evolution models for young, metal-poor stars if the cluster's metallicity can be established via high-resolution spectroscopy.
Almeida, Mathieu; Hébert, Agnès; Abraham, Anne-Laure; Rasmussen, Simon; Monnet, Christophe; Pons, Nicolas; Delbès, Céline; Loux, Valentin; Batto, Jean-Michel; Leonard, Pierre; Kennedy, Sean; Ehrlich, Stanislas Dusko; Pop, Mihai; Montel, Marie-Christine; Irlinger, Françoise; Renault, Pierre
2014-12-13
Microbial communities of traditional cheeses are complex and insufficiently characterized. The origin, safety and functional role in cheese making of these microbial communities are still not well understood. Metagenomic analysis of these communities by high throughput shotgun sequencing is a promising approach to characterize their genomic and functional profiles. Such analyses, however, critically depend on the availability of appropriate reference genome databases against which the sequencing reads can be aligned. We built a reference genome catalog suitable for short read metagenomic analysis using a low-cost sequencing strategy. We selected 142 bacteria isolated from dairy products belonging to 137 different species and 67 genera, and succeeded to reconstruct the draft genome of 117 of them at a standard or high quality level, including isolates from the genera Kluyvera, Luteococcus and Marinilactibacillus, still missing from public database. To demonstrate the potential of this catalog, we analysed the microbial composition of the surface of two smear cheeses and one blue-veined cheese, and showed that a significant part of the microbiota of these traditional cheeses was composed of microorganisms newly sequenced in our study. Our study provides data, which combined with publicly available genome references, represents the most expansive catalog to date of cheese-associated bacteria. Using this extended dairy catalog, we revealed the presence in traditional cheese of dominant microorganisms not deliberately inoculated, mainly Gram-negative genera such as Pseudoalteromonas haloplanktis or Psychrobacter immobilis, that may contribute to the characteristics of cheese produced through traditional methods.
Eggleton, M.A.; Schramm, H.L.
2004-01-01
We examined feeding of blue catfish, Ictalurus furcatus, and flathead catfish, Pylodictis olivaris, collected from floodplain lake, secondary (side) river channel, and main river channel habitats in the lower Mississippi River (LMR), U.S.A. We described the feeding ecology of two large river catfish species within the context of whether off-channel habitats in the LMR (i.e., floodplain lakes and secondary channels) potentially provided energetic benefits to these fishes as purported in contemporary theory on the ecology of large rivers. We used diet composition and associated caloric densities of prey consumed as indicators of energetic benefit to catfishes. Differences in diet among habitats were strong for blue catfish, but weak for flathead catfish; consumed foods generally differed among habitats in caloric (energy) content. Caloric densities of consumed foods were generally greatest in floodplain lakes, least in the main river channel, and intermediate in secondary river channels. Strong between-year variation in diet was observed, but only for blue catfish. Blue catfish fed disproportionately on lower-energy zebra mussels in the main river channel during 1997, and higher-energy chironomids and oligochaetes in floodplain lakes during 1998. Results suggested that although off-channel habitats potentially provided greater energetic return to catfishes in terms of foods consumed, patterns of feeding and subsequent energy intake may vary annually. Energetic benefits associated with off-channel habitats as purported under contemporary theory (e.g., the 'flood-pulse concept') may not be accrued by catfishes every year in the LMR.
Henze, Miriam J; Dannenhauer, Kara; Kohler, Martin; Labhart, Thomas; Gesemann, Matthias
2012-08-30
Opsins are key proteins in animal photoreception. Together with a light-sensitive group, the chromophore, they form visual pigments which initiate the visual transduction cascade when photoactivated. The spectral absorption properties of visual pigments are mainly determined by their opsins, and thus opsins are crucial for understanding the adaptations of animal eyes. Studies on the phylogeny and expression pattern of opsins have received considerable attention, but our knowledge about insect visual opsins is still limited. Up to now, researchers have focused on holometabolous insects, while general conclusions require sampling from a broader range of taxa. We have therefore investigated visual opsins in the ocelli and compound eyes of the two-spotted cricket Gryllus bimaculatus, a hemimetabolous insect. Phylogenetic analyses place all identified cricket sequences within the three main visual opsin clades of insects. We assign three of these opsins to visual pigments found in the compound eyes with peak absorbances in the green (515 nm), blue (445 nm) and UV (332 nm) spectral range. Their expression pattern divides the retina into distinct regions: (1) the polarization-sensitive dorsal rim area with blue- and UV-opsin, (2) a newly-discovered ventral band of ommatidia with blue- and green-opsin and (3) the remainder of the compound eye with UV- and green-opsin. In addition, we provide evidence for two ocellar photopigments with peak absorbances in the green (511 nm) and UV (350 nm) spectral range, and with opsins that differ from those expressed in the compound eyes. Our data show that cricket eyes are spectrally more specialized than has previously been assumed, suggesting that similar adaptations in other insect species might have been overlooked. The arrangement of spectral receptor types within some ommatidia of the cricket compound eyes differs from the generally accepted pattern found in holometabolous insect taxa and awaits a functional explanation. From the opsin phylogeny, we conclude that gene duplications, which permitted differential opsin expression in insect ocelli and compound eyes, occurred independently in several insect lineages and are recent compared to the origin of the eyes themselves.
2012-01-01
Background Opsins are key proteins in animal photoreception. Together with a light-sensitive group, the chromophore, they form visual pigments which initiate the visual transduction cascade when photoactivated. The spectral absorption properties of visual pigments are mainly determined by their opsins, and thus opsins are crucial for understanding the adaptations of animal eyes. Studies on the phylogeny and expression pattern of opsins have received considerable attention, but our knowledge about insect visual opsins is still limited. Up to now, researchers have focused on holometabolous insects, while general conclusions require sampling from a broader range of taxa. We have therefore investigated visual opsins in the ocelli and compound eyes of the two-spotted cricket Gryllus bimaculatus, a hemimetabolous insect. Results Phylogenetic analyses place all identified cricket sequences within the three main visual opsin clades of insects. We assign three of these opsins to visual pigments found in the compound eyes with peak absorbances in the green (515 nm), blue (445 nm) and UV (332 nm) spectral range. Their expression pattern divides the retina into distinct regions: (1) the polarization-sensitive dorsal rim area with blue- and UV-opsin, (2) a newly-discovered ventral band of ommatidia with blue- and green-opsin and (3) the remainder of the compound eye with UV- and green-opsin. In addition, we provide evidence for two ocellar photopigments with peak absorbances in the green (511 nm) and UV (350 nm) spectral range, and with opsins that differ from those expressed in the compound eyes. Conclusions Our data show that cricket eyes are spectrally more specialized than has previously been assumed, suggesting that similar adaptations in other insect species might have been overlooked. The arrangement of spectral receptor types within some ommatidia of the cricket compound eyes differs from the generally accepted pattern found in holometabolous insect taxa and awaits a functional explanation. From the opsin phylogeny, we conclude that gene duplications, which permitted differential opsin expression in insect ocelli and compound eyes, occurred independently in several insect lineages and are recent compared to the origin of the eyes themselves. PMID:22935102
Kim, Jin Kyoung; Shin, So-Yeon; Moon, Jin Seok; Li, Ling; Cho, Seung Kee; Kim, Tae-Jip; Han, Nam Soo
2015-06-01
The aim of this study was to isolate dextran-hydrolyzing bacteria from the human intestines and to identify their dextranolytic enzymes. For this, dextranase-producing microorganisms were screened from fecal samples by using blue dextran-containing media. Colonies producing a decolorized zone were isolated and they were grouped using RAPD-PCR. 16S rRNA gene sequencing analysis revealed the isolates were Bacteroides (B.) thetaiotaomicron, B. ovatus, B. vulgatus, B. dorei, B. xylanisolvens, B. uniformis, and Veillonella (V.) rogosae. Thin layer chromatography analysis showed that the dextranases exhibit mainly endo-type activity and produce various oligosaccharides including isomaltose and isomaltotriose. Zymogram analysis demonstrated that enzymes localized mainly in the cell membrane fraction and the molecular weight was 50-70 kDa. When cultured in a dextran-containing medium, all strains isolated in this study produced short-chain fatty acids, with butyric acid as the major compound. This is the first study to report that human intestinal B. xylanisolvens, B. dorei, and V. rogosae metabolize dextran utilizing dextranolytic enzymes. © 2015 Wiley Periodicals, Inc.
Beel, Benedikt; Prager, Katja; Spexard, Meike; Sasso, Severin; Weiss, Daniel; Müller, Nico; Heinnickel, Mark; Dewez, David; Ikoma, Danielle; Grossman, Arthur R.; Kottke, Tilman; Mittag, Maria
2012-01-01
Cryptochromes are flavoproteins that act as sensory blue light receptors in insects, plants, fungi, and bacteria. We have investigated a cryptochrome from the green alga Chlamydomonas reinhardtii with sequence homology to animal cryptochromes and (6-4) photolyases. In response to blue and red light exposure, this animal-like cryptochrome (aCRY) alters the light-dependent expression of various genes encoding proteins involved in chlorophyll and carotenoid biosynthesis, light-harvesting complexes, nitrogen metabolism, cell cycle control, and the circadian clock. Additionally, exposure to yellow but not far-red light leads to comparable increases in the expression of specific genes; this expression is significantly reduced in an acry insertional mutant. These in vivo effects are congruent with in vitro data showing that blue, yellow, and red light, but not far-red light, are absorbed by the neutral radical state of flavin in aCRY. The aCRY neutral radical is formed following blue light absorption of the oxidized flavin. Red illumination leads to conversion to the fully reduced state. Our data suggest that aCRY is a functionally important blue and red light–activated flavoprotein. The broad spectral response implies that the neutral radical state functions as a dark form in aCRY and expands the paradigm of flavoproteins and cryptochromes as blue light sensors to include other light qualities. PMID:22773746
USDA-ARS?s Scientific Manuscript database
Pomes, mainly apples and pears, are economically important fruits produced and consumed worldwide. The United States is the second largest producer of pome fruit in the world behind China. Penicillium expansum and other Penicillium spp. are the most common fungal plant pathogens that cause blue mold...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-16
........ May 30, 2011. Shield of Maine, WellPoint, Inc., Enterprise Business Services, Aerotek, etc. 81,664A Anthem Blue Cross Blue Manchester, NH......... May 30, 2011. Shield of New Hampshire, WellPoint, Inc..., 2011. Shield of Connecticut, WellPoint, Inc., Enterprise Business Services, Aerotek, etc. 81,710 Sun...
Acorn Size as a Factor in Early Seedling Growth of Blue Oaks
Jerry Tecklin; Douglas D. McCreary
1991-01-01
Field performance was evaluated for blue oak (Quercus douglasii Hook. & Am.) acorns of different size classes (weights) and from different trees which produced predominantly small, medium, or large acorns. Emergence, height, and survival were monitored for two growing seasons. A parallel evaluation, mainly of root characteristics, was conducted...
Schill, William B.; Iwanowicz, Deborah; Adams, Cynthia
2017-01-01
Blue mussels, Mytilus edulis, Linnaeus 1758 from southern Barnegat Bay, New Jersey were examined to determine the make-up of the normal blue mussel microbiome. Sequencing of 16S ribosomal DNA amplicons from gill and intestinal content microbiomes using the Illumina® MiSeq platform yielded 1,276,161 paired end sequence reads from the gill libraries and 1,092,333 paired end sequence reads from the intestinal content libraries. General bioinformatic analyses were conducted with the open-source packages Qiime and Mothur. Phylotype assignments to the genus level were made using the commercial One Codex platform. This resulted in 1,697,852 gill and 988,436 intestinal content sequences being classified to genus. A majority of these (67.6% and 37.2% respectively) were assigned to a single operational taxonomic unit (Mytilus edulis Symbiont, MeS) that has homologies with other recently described Endozoicomonas pathogens and symbionts of marine invertebrates. MeS shares 98% identity with an uncultured bacterium from the gill tissue of an invasive indo-Pacific oyster and with HQE1 and HQE2 isolated from the sea squirt, Styela clava. Other than MeS, most of the detected bacterial species are known from marine sediments and seawater.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ko, Jongwan; Im, Myungshin; Lee, Hyung Mok
2012-02-01
We present the mid-infrared (MIR) properties of galaxies within a supercluster in the north ecliptic pole region at z {approx} 0.087 observed with the AKARI satellite. We use data from the AKARI NEP-Wide (5.4 deg{sup 2}) IR survey and the CLusters of galaxies EVoLution studies (CLEVL) mission program. We show that near-IR (3 {mu}m)-mid-IR (11 {mu}m) color can be used as an indicator of the specific star formation rate and the presence of intermediate-age stellar populations. From the MIR observations, we find that red-sequence galaxies consist not only of passively evolving red early-type galaxies, but also of (1) 'weak-SFGs' (disk-dominatedmore » star-forming galaxies that have star formation rates lower by {approx}4 Multiplication-Sign than blue-cloud galaxies) and (2) 'intermediate-MXGs' (bulge-dominated galaxies showing stronger MIR dust emission than normal red early-type galaxies). These two populations can be a set of transition galaxies from blue, star-forming, late-type galaxies evolving into red, quiescent, early-type ones. We find that the weak-SFGs are predominant at intermediate masses (10{sup 10} M{sub Sun} < M{sub *} < 10{sup 10.5} M{sub Sun }) and are typically found in local densities similar to the outskirts of galaxy clusters. As much as 40% of the supercluster member galaxies in this mass range can be classified as weak-SFGs, but their proportion decreases to <10% at larger masses (M{sub *} > 10{sup 10.5} M{sub Sun }) at any galaxy density. The fraction of the intermediate-MXG among red-sequence galaxies at 10{sup 10} M{sub Sun} < M{sub *} < 10{sup 11} M{sub Sun} also decreases as the density and mass increase. In particular, {approx}42% of the red-sequence galaxies with early-type morphologies are classified as intermediate-MXGs at intermediate densities. These results suggest that the star formation activity is strongly dependent on the stellar mass, but that the morphological transformation is mainly controlled by the environment.« less
Cicala, Francesco; Moore, James D; Cáceres-Martínez, Jorge; Del Río-Portilla, Miguel A; Hernández-Rodríguez, Mónica; Vásquez-Yeomans, Rebeca; Rocha-Olivares, Axayácatl
2018-05-01
Withering syndrome (WS) is a chronic wasting disease affecting abalone species attributed to the pathogen Candidatus Xenohaliotis californiensis (CXc). Wild populations of blue (Haliotis fulgens) and yellow (H. corrugata) abalone have experienced unusual mortality rates since 2009 off the peninsula of Baja California and WS has been hypothesized as a possible cause. Currently, little information is available about the genetic diversity of CXc and particularly the possible existence of strains differing in pathogenicity. In a recent phylogenetic analysis, we characterized five coding genes from this rickettsial pathogen. Here, we analyze those genes and two additional intergenic non-coding regions following multi-locus sequence typing (MLST) and multi-spacer typing (MST) approaches to assess the genetic variability of CXc and its relationship with blue, yellow and red (H. rufescens) abalone. Moreover, we used 16S rRNA pyrosequencing reads from gut microbiomes of blue and yellow abalone to complete the genetic characterization of this prokaryote. The presence of CXc was investigated in more than 150 abalone of the three species; furthermore, a total of 385 DNA sequences and 7117 16S rRNA reads from Candidatus Xenohaliotis californiensis were used to evaluate its population genetic structure. Our findings suggest the absence of polymorphism in the DNA sequences of analyzed loci and the presence of a single lineage of CXc infecting abalone from California (USA) and Baja California (Mexico). We posit that the absence of genetic variably in this marine rickettsia may be the result of evolutionary and ecological processes. Copyright © 2018 Elsevier Inc. All rights reserved.
Resolved photometry of extragalactic young massive star clusters
NASA Astrophysics Data System (ADS)
Larsen, S. S.; de Mink, S. E.; Eldridge, J. J.; Langer, N.; Bastian, N.; Seth, A.; Smith, L. J.; Brodie, J.; Efremov, Yu. N.
2011-08-01
Aims: We present colour-magnitude diagrams (CMDs) of young massive star clusters in several galaxies located well beyond the Local Group. The richness of these clusters allows us to obtain large samples of post-main sequence stars and test how well the observed CMDs are reproduced by canonical stellar isochrones. Methods: We use imaging of seven clusters in the galaxies NGC 1313, NGC 1569, NGC 1705, NGC 5236 and NGC 7793 obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope and carry out PSF-fitting photometry of individual stars in the clusters. The clusters have ages in the range ~(5-50) × 106 years and masses of ~105 M⊙-106 M⊙. Although crowding prevents us from obtaining photometry in the inner regions of the clusters, we are still able to measure up to 30-100 supergiant stars in each of the richest clusters. The resulting CMDs and luminosity functions are compared with photometry of artificially generated clusters, designed to reproduce the photometric errors and completeness as realistically as possible. Results: In agreement with previous studies, our CMDs show no clear gap between the H-burning main sequence and the He-burning supergiant stars, contrary to predictions by common stellar isochrones. In general, the isochrones also fail to match the observed number ratios of red-to-blue supergiant stars, although the difficulty of separating blue supergiants from the main sequence complicates this comparison. In several cases we observe a large spread (1-2 mag) in the luminosities of the supergiant stars that cannot be accounted for by observational errors. We find that this spread can be reproduced by including an age spread of ~(10-30) × 106 years in the models. However, age spreads cannot fully account for the observed morphology of the CMDs and other processes, such as the evolution of interacting binary stars, may also play a role. Conclusions: Colour-magnitude diagrams can be successfully obtained for massive star clusters out to distances of at least 4-5 Mpc. Comparing such CMDs with models based on canonical isochrones we find several areas of disagreement. One interesting possibility is that an age spread of up to ~30 Myr may be present in some clusters. The data presented here may provide useful constraints on models for single and/or binary stellar evolution. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the association of Universities for Research in Astronomy, Inc. under the NASA contract NAS 5-26555Tables 4-10 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/532/A147
Blue two-photon fluorescence metal cluster probe precisely marking cell nuclei of two cell lines.
Wang, Yaling; Cui, Yanyan; Liu, Ru; Wei, Yueteng; Jiang, Xinglu; Zhu, Huarui; Gao, Liang; Zhao, Yuliang; Chai, Zhifang; Gao, Xueyun
2013-11-25
A bifunctional peptide was designed to in situ reduce Cu ions and anchor a Cu cluster. The peptide-Cu cluster probe, mainly composed of Cu14, emitted blue two-photon fluorescence under femtosecond laser excitation. Most important, the probe can specifically mark the nuclei of HeLa and A549 cells, respectively.
Activating cysteinyl leukotriene receptor 2 (CYSLTR2) mutations in blue nevi
Möller, Inga; Murali, Rajmohan; Müller, Hansgeorg; Wiesner, Thomas; Jackett, Louise A; Scholz, Simone L; Cosgarea, Ioana; van de Nes, Johannes AP; Sucker, Antje; Hillen, Uwe; Schilling, Bastian; Paschen, Annette; Kutzner, Heinz; Rütten, Arno; Böckers, Martin; Scolyer, Richard A; Schadendorf, Dirk; Griewank, Klaus G
2017-01-01
Blue nevi are common melanocytic tumors arising in the dermal layer of the skin. Similar to uveal melanomas, blue nevi frequently harbor GNAQ and GNA11 mutations. Recently, recurrent CYSLTR2 and PLCB4 mutations were identified in uveal melanomas not harboring GNAQ or GNA11 mutations. All four genes (GNAQ, GNA11, CYSLTR2, and PLCB4) code for proteins involved in the same signaling pathway, which is activated by mutations in these genes. Given the related functional consequences of these mutations and the known genetic similarities between uveal melanoma and blue nevi, we analyzed a cohort of blue nevi to investigate whether CYSLTR2 and PLCB4 mutations occur in tumors lacking GNAQ or GNA11 mutations (as in uveal melanoma). A targeted next-generation sequencing assay covering known activating mutations in GNAQ, GNA11, CYSLTR2, PLCB4, KIT, NRAS, and BRAF was applied to 103 blue nevi. As previously reported, most blue nevi were found to harbor activating mutations in GNAQ (59%, n = 61), followed by less frequent mutations in GNA11 (16%, n = 17). Additionally, one BRAF (1%) and three NRAS (3%) mutations were detected. In three tumors (3%) harboring none of the aforementioned gene alterations, CYSLTR2 mutations were identified. All three CYSLTR2 mutations were the same c.386T > A, L129Q mutation previously identified in uveal melanoma that has been shown to lead to increased receptor activation and signaling. In summary, our study identifies CYSLTR2 L129Q alterations as a previously unrecognized activating mutation in blue nevi, occuring in a mutually exclusive fashion with known GNAQ and GNA11 mutations. Similar to GNAQ and GNA11 mutations, CYSLTR2 mutations, when present, are likely defining pathogenetic events in blue nevi. PMID:27934878
Activating cysteinyl leukotriene receptor 2 (CYSLTR2) mutations in blue nevi.
Möller, Inga; Murali, Rajmohan; Müller, Hansgeorg; Wiesner, Thomas; Jackett, Louise A; Scholz, Simone L; Cosgarea, Ioana; van de Nes, Johannes Ap; Sucker, Antje; Hillen, Uwe; Schilling, Bastian; Paschen, Annette; Kutzner, Heinz; Rütten, Arno; Böckers, Martin; Scolyer, Richard A; Schadendorf, Dirk; Griewank, Klaus G
2017-03-01
Blue nevi are common melanocytic tumors arising in the dermal layer of the skin. Similar to uveal melanomas, blue nevi frequently harbor GNAQ and GNA11 mutations. Recently, recurrent CYSLTR2 and PLCB4 mutations were identified in uveal melanomas not harboring GNAQ or GNA11 mutations. All four genes (GNAQ, GNA11, CYSLTR2, and PLCB4) code for proteins involved in the same signaling pathway, which is activated by mutations in these genes. Given the related functional consequences of these mutations and the known genetic similarities between uveal melanoma and blue nevi, we analyzed a cohort of blue nevi to investigate whether CYSLTR2 and PLCB4 mutations occur in tumors lacking GNAQ or GNA11 mutations (as in uveal melanoma). A targeted next-generation sequencing assay covering known activating mutations in GNAQ, GNA11, CYSLTR2, PLCB4, KIT, NRAS, and BRAF was applied to 103 blue nevi. As previously reported, most blue nevi were found to harbor activating mutations in GNAQ (59%, n=61), followed by less frequent mutations in GNA11 (16%, n=17). Additionally, one BRAF (1%) and three NRAS (3%) mutations were detected. In three tumors (3%) harboring none of the aforementioned gene alterations, CYSLTR2 mutations were identified. All three CYSLTR2 mutations were the same c.386T>A, L129Q mutation previously identified in uveal melanoma that has been shown to lead to increased receptor activation and signaling. In summary, our study identifies CYSLTR2 L129Q alterations as a previously unrecognized activating mutation in blue nevi, occuring in a mutually exclusive fashion with known GNAQ and GNA11 mutations. Similar to GNAQ and GNA11 mutations, CYSLTR2 mutations, when present, are likely defining pathogenetic events in blue nevi.
Qian, Hongmei; Liu, Tianyu; Deng, Mingdan; Miao, Huiying; Cai, Congxi; Shen, Wangshu; Wang, Qiaomei
2016-04-01
The effects of different light qualities, including white, red and blue lights, on main health-promoting compounds and antioxidant capacity of Chinese kale sprouts were investigated using light-emitting diodes (LEDs) as a light source. Our results showed that blue light treatment significantly decreased the content of gluconapin, the primary compound for bitter flavor in shoots, while increased the glucoraphanin content in roots. Moreover, the maximum content of vitamin C was detected in the white-light grown sprouts and the highest levels of total phenolic and anthocyanins, as well as the strongest antioxidant capacity were observed in blue-light grown sprouts. Taken together, the application of a colorful light source is a good practice for improvement of the consumers' acceptance and the nutritional phtyochemicals of Chinese kale sprouts. Copyright © 2015 Elsevier Ltd. All rights reserved.
On the fourth Diadema species (Diadema-sp) from Japan.
Chow, Seinen; Kajigaya, Yoshikazu; Kurogi, Hiroaki; Niwa, Kentaro; Shibuno, Takuro; Nanami, Atsushi; Kiyomoto, Setuo
2014-01-01
Four long-spined sea urchin species in the genus Diadema are known to occur around the Japanese Archipelago. Three species (D. savignyi, D. setosum, and D. paucispinum) are widely distributed in the Indo-Pacific Ocean. The fourth species was detected by DNA analysis among samples originally collected as D. savignyi or D. setosum in Japan and the Marshall Islands and tentatively designated as Diadema-sp, remaining an undescribed species. We analyzed nucleotide sequences of the cytochrome oxidase I (COI) gene in the "D. savignyi-like" samples, and found all 17 individuals collected in the mainland of Japan (Sagami Bay and Kyushu) to be Diadema-sp, but all nine in the Ryukyu Archipelago (Okinawa and Ishigaki Islands) to be D. savignyi, with large nucleotide sequence difference between them (11.0%±1.7 SE). Diadema-sp and D. savignyi shared Y-shaped blue lines of iridophores along the interambulacrals, but individuals of Diadema-sp typically exhibited a conspicuous white streak at the fork of the Y-shaped blue iridophore lines, while this feature was absent in D. savignyi. Also, the central axis of the Y-shaped blue lines of iridophores was approximately twice as long as the V-component in D. savignyi whereas it was of similar length in Diadema-sp. Two parallel lines were observed to constitute the central axis of the Y-shaped blue lines in both species, but these were considerably narrower in Diadema-sp. Despite marked morphological and genetic differences, it appears that Diadema-sp has been mis-identified as D. savignyi for more than half a century.
Tian, Roger B D; Asmar, Shady; Napez, Claude; Lépidi, Hubert; Drancourt, Michel
2017-03-01
Mycobacterium ulcerans is responsible for Buruli ulcer, characterised by extensive, disabling ulcers. Standard treatment combining rifampicin and streptomycin exposes patients to toxicity and daily painful injections. In this study, the in vitro susceptibilities of 3 M. ulcerans strains, 1 Mycobacterium marinum strain and 18 strains representative of eleven other Mycobacterium species and subspecies to methylene blue were determined. Whilst growth of M. ulcerans was inhibited by 0.0125 g/L methylene blue, growth of all other tested strains was not inhibited by 1 g/L methylene blue. The effectiveness of methylene blue in a murine model of M. ulcerans infection was then tested. Topical treatment by brushing a methylene blue solution on the skin lesion, systemic treatment by intraperitoneal injection of methylene blue, and a combined treatment (topical and systemic) were tested. The three treatment groups exhibited a significantly lower clinical score compared with the non-treated control group (P <0.05). Moreover, subcutaneous nodules were significantly smaller in the systemic treatment group (excluding males) (3 ± 0.7 mm) compared with the other groups (P <0.05). The M. ulcerans insertion sequence IS2404 and the KR-B gene were detected in all challenged mice, but not in negative controls. The density of M. ulcerans (mycobacteria/cell) was significantly lower in the combined treatment group compared with the other groups. These data provide evidence for the effectiveness of purified methylene blue against the initial stage of Buruli ulcer. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
Kusumi, Asako; Li, Xianshu; Osuga, Yu; Kawashima, Arata; Gu, Ji-Dong; Nasu, Masao; Katayama, Yoko
2013-01-01
The Bayon temple in Angkor Thom, Cambodia has shown serious deterioration and is subject to the formation of various pigmented biofilms. Because biofilms are damaging the bas-reliefs, low reliefs engraved on the surface of sandstone, information about the microbial community within them is indispensable to control biofilm colonization. PCR-denaturing gradient gel electrophoresis (DGGE) analysis of biofilm samples from the pigmented sandstone surfaces showed that the bacterial community members in the biofilms differed clearly from those in the air and had low sequence similarity to database sequences. Non-destructive sampling of biofilm revealed novel bacterial groups of predominantly Rubrobacter in salmon pink biofilm, Cyanobacteria in chrome green biofilm, Cyanobacteria and Chloroflexi in signal violet biofilm, Chloroflexi in black gray biofilm, and Deinococcus-Thermus, Cyanobacteria, and Rubrobacter in blue green biofilm. Serial peeling-off of a thick biofilm by layers with adhesive sheets revealed a stratified structure: the blue-green biofilm, around which there was serious deterioration, was very rich in Cyanobacteria near the surface and Chloroflexi in deep layer below. Nitrate ion concentrations were high in the blue-green biofilm. The characteristic distribution of bacteria at different biofilm depths provides valuable information on not only the biofilm formation process but also the sandstone weathering process in the tropics.
Jeong, Hyeonsoo; Kim, Kwondo; Caetano-Anollés, Kelsey; Kim, Heebal; Kim, Byung-Ki; Yi, Jun-Koo; Ha, Jae-Jung; Cho, Seoae; Oh, Dong Yep
2016-05-24
Chicken, Gallus gallus, is a valuable species both as a food source and as a model organism for scientific research. Here, we sequenced the genome of Gyeongbuk Araucana, a rare chicken breed with unique phenotypic characteristics including flight ability, large body size, and laying blue-shelled eggs, to identify its genomic features. We generated genomes of Gyeongbuk Araucana, Leghorn, and Korean Native Chicken at a total of 33.5, 35.82, and 33.23 coverage depth, respectively. Along with the genomes of 12 Chinese breeds, we identified genomic variants of 16.3 million SNVs and 2.3 million InDels in mapped regions. Additionally, through assembly of unmapped reads and selective sweep, we identified candidate genes that fall into heart, vasculature and muscle development and body growth categories, which provided insight into Gyeongbuk Araucana's phenotypic traits. Finally, genetic variation based on the transposable element insertion pattern was investigated to elucidate the features of transposable elements related to blue egg shell formation. This study presents results of the first genomic study on the Gyeongbuk Araucana breed; it has potential to serve as an invaluable resource for future research on the genomic characteristics of this chicken breed as well as others.
Detection of Antibodies in Blood Plasma Using Bioluminescent Sensor Proteins and a Smartphone.
Arts, Remco; den Hartog, Ilona; Zijlema, Stefan E; Thijssen, Vito; van der Beelen, Stan H E; Merkx, Maarten
2016-04-19
Antibody detection is of fundamental importance in many diagnostic and bioanalytical assays, yet current detection techniques tend to be laborious and/or expensive. We present a new sensor platform (LUMABS) based on bioluminescence resonance energy transfer (BRET) that allows detection of antibodies directly in solution using a smartphone as the sole piece of equipment. LUMABS are single-protein sensors that consist of the blue-light emitting luciferase NanoLuc connected via a semiflexible linker to the green fluorescent acceptor protein mNeonGreen, which are kept close together using helper domains. Binding of an antibody to epitope sequences flanking the linker disrupts the interaction between the helper domains, resulting in a large decrease in BRET efficiency. The resulting change in color of the emitted light from green-blue to blue can be detected directly in blood plasma, even at picomolar concentrations of antibody. Moreover, the modular architecture of LUMABS allows changing of target specificity by simple exchange of epitope sequences, as demonstrated here for antibodies against HIV1-p17, hemagglutinin (HA), and dengue virus type I. The combination of sensitive ratiometric bioluminescent detection and the intrinsic modularity of the LUMABS design provides an attractive generic platform for point-of-care antibody detection that avoids the complex liquid handling steps associated with conventional immunoassays.
Atkinson, Stephen Douglas; Banner, Craig Randall
2017-01-01
Blue chub, Gila coerulea Girard, 1856 is a freshwater cyprinid fish native to inland drainages of western North America. It has not previously been recorded as a host of any myxosporean parasite (Cnidaria: Myxosporea), despite myxosporeans being cosmopolitan in freshwater and marine fishes worldwide and sympatric with this host. Herein, we describe a novel myxosporean from subcutaneous cysts in native blue chub from Klamath Lake, Oregon. Myxospores were consistent with genus Myxobolus, being obovoid but compressed in thickness, length 14.3 ± 0.4 (13-15) μm, width 9.7 ± 0.4 (9-10) μm, thickness 7.7 ± 0.3 (7-8) μm; two polar capsules ovoid slightly dissimilar in size, length 6.4 ± 0.4 (6-7) μm, width 3.8 ± 0.3 (3-4) μm, with four (3-5) turns of the polar filament (tubule); capsule openings apical, one in each valve cell. The small subunit ribosomal DNA sequence was up to 97 % similar to Myxobolus spp. from other cyprinids from North America and Europe. Given the novel host, unique myxospore morphometrics, and DNA sequence, we describe this as Myxobolus klamathellus n. sp.
Ahlstrøm, Øystein; Fuglei, Eva; Mydland, Liv Torunn
2003-01-01
Arctic foxes from Svalbard (n=4) and farmed blue foxes (n=4) was used in a digestibility experiment with a high-carbohydrate feed to add more information to the nutritional physiology of the arctic fox, and to compare its digestive capacity with that of the farmed blue fox. The arctic fox has a diet containing mainly protein and fat from mammals and birds, while farmed blue foxes have been exposed to an omnivorous dietary regime for more than 80 generations. The experiment showed in general no difference in digestive capacity for protein and fat between the foxes (P>0.05), but for carbohydrates, including starch and glucose, the blue fox revealed higher digestibility values. The superior digestive capacity for carbohydrates in blue fox might be a result of a long-term selection of animals digesting dietary carbohydrates more efficiently, or that an early age exposition to dietary carbohydrates has given permanent improvement of the carbohydrate digestion in the gut.
Schut, Elske; Aguilar, Juan Rivero-de; Merino, Santiago; Magrath, Michael J L; Komdeur, Jan; Westerdahl, Helena
2011-08-01
The major histcompatibility complex (MHC) is a vital component of the adaptive immune system in all vertebrates. This study is the first to characterize MHC class I (MHC-I) in blue tits (Cyanistes caeruleus), and we use MHC-I exon 3 sequence data from individuals originating from three locations across Europe: Spain, the Netherlands to Sweden. Our phylogeny of the 17 blue tit MHC-I alleles contains one allele cluster with low nucleotide diversity compared to the remaining more diverse alleles. We found a significant evidence for balancing selection in the peptide-binding region in the diverse allele group only. No separation according to geographic location was found in the phylogeny of alleles. Although the number of MHC-I loci of the blue tit is comparable to that of other passerine species, the nucleotide diversity of MHC-I appears to be much lower than that of other passerine species, including the closely related great tit (Parus major) and the severely inbred Seychelles warbler (Acrocephalus sechellensis). We believe that this initial MHC-I characterization in blue tits provides an important step towards understanding the mechanisms shaping MHC-I diversity in natural populations.
COSMIC-LAB: Double BSS sequences as signatures of the Core Collapse phenomenon in star clusters.
NASA Astrophysics Data System (ADS)
Ferraro, Francesco
2011-10-01
Globular Clusters {GCs} are old stellar systems tracing key stages of the star formation and chemical enrichment history of the early Universe and the galaxy assembly phase. As part of a project {COSMIC-LAB} aimed at using GCs as natural laboratories to study the complex interplay between dynamics and stellar evolution, here we present a proposal dealing with the role of Blue Straggler Stars {BSS}.BSS are core-hydrogen burning stars more massive than the main-sequence turnoff population. The canonical scenarios for BSS formation are either the mass transfer between binary companions, or stellar mergers induced by collisions. We have recently discovered two distinct and parallel sequences of BSS in the core of M30 {Ferraro et al. 2009, Nature 462, 1082}. We suggested that each of the two sequences is populated by BSS formed by one of the two processes, both triggered by the cluster core collapse, that, based on the observed BSS properties, must have occurred 1-2 Gyr ago. Following this scenario, we have identified a powerful "clock" to date the occurrence of this key event in the GC history.Here we propose to secure WFC3 images of 4 post-core collapse GCs, reaching S/N=200 at the BSS magnitude level, in order to determine the ubiquity of the BSS double sequence and calibrate the "dynamical clock". This requires very high spatial resolution and very high precision photometry capabilities that are unique to the HST. The modest amount of requested time will have a deep impact on the current and future generations of dynamical evolutionary models of collisional stellar systems.
NASA Astrophysics Data System (ADS)
Beedle, Amy E. M.; Lezamiz, Ainhoa; Stirnemann, Guillaume; Garcia-Manyes, Sergi
2015-08-01
Understanding the directionality and sequence of protein unfolding is crucial to elucidate the underlying folding free energy landscape. An extra layer of complexity is added in metalloproteins, where a metal cofactor participates in the correct, functional fold of the protein. However, the precise mechanisms by which organometallic interactions are dynamically broken and reformed on (un)folding are largely unknown. Here we use single molecule force spectroscopy AFM combined with protein engineering and MD simulations to study the individual unfolding pathways of the blue-copper proteins azurin and plastocyanin. Using the nanomechanical properties of the native copper centre as a structurally embedded molecular reporter, we demonstrate that both proteins unfold via two independent, competing pathways. Our results provide experimental evidence of a novel kinetic partitioning scenario whereby the protein can stochastically unfold through two distinct main transition states placed at the N and C termini that dictate the direction in which unfolding occurs.
On the luminosity function, lifetimes, and origin of blue stragglers in globular clusters
NASA Technical Reports Server (NTRS)
Bailyn, Charles D.; Pinsonneault, Marc H.
1995-01-01
We compute theoretical evolutionary tracks of blue stragglers created by mergers. Two formation scenarios are considered: mergers of primordial binaries, and stellar collisions. These two scenarios predict strikingly different luminosity functions, which are potentially distinguishable observationally. Tabulated theoretical luminosity functions and lifetimes are presented for blue stragglers formed under a variety of input conditions. We compare our results with observations of the blue straggler sequences in 47 Tucanae and M3. In the case of 47 Tuc, the luminosity function and the formation rate are compatible with the hypothesis that the blue stragglers formed through the collision of single stars. Mergers of primordial binaries are only marginally cosistent with the data, and a significant enhancement of the collision cross section by binary-single-star encounters appears to be ruled out. In the case of M3, we find that the innermost blue stragglers have a luminosity function significantly different from that of the outer stragglers, thus confirming earlier suggestions that there are two distinct populations of blue stragglers in this cluster. The inner stragglers are preferentially brighter and bluer, as would be expected if they were made by collisions, but there are so many of them that the collision rate would need to be enhanced by interactions involving wide binaries. The luminosity function of the outer stragglers is almost identical to the predictions of mergers from primordial binaries and is inconsistent with the collision hypothesis.
NASA Astrophysics Data System (ADS)
Ferraro, F. R.; Lanzoni, B.; Raso, S.; Nardiello, D.; Dalessandro, E.; Vesperini, E.; Piotto, G.; Pallanca, C.; Beccari, G.; Bellini, A.; Libralato, M.; Anderson, J.; Aparicio, A.; Bedin, L. R.; Cassisi, S.; Milone, A. P.; Ortolani, S.; Renzini, A.; Salaris, M.; van der Marel, R. P.
2018-06-01
The parameter A +, defined as the area enclosed between the cumulative radial distribution of blue straggler stars (BSSs) and that of a reference population, is a powerful indicator of the level of BSS central segregation. As part of the Hubble Space Telescope UV Legacy Survey of Galactic globular clusters (GCs), here we present the BSS population and the determination of A + in 27 GCs observed out to about one half-mass radius. In combination with 21 additional clusters discussed in a previous paper, this provides us with a global sample of 48 systems (corresponding to ∼32% of the Milky Way GC population), for which we find a strong correlation between A + and the ratio of cluster age to the current central relaxation time. Tight relations have also been found with the core radius and the central luminosity density, which are expected to change with the long-term cluster dynamical evolution. An interesting relation is emerging between A + and the ratio of the BSS velocity dispersion relative to that of main sequence turn-off stars, which measures the degree of energy equipartition experienced by BSSs in the cluster. These results provide further confirmation that BSSs are invaluable probes of GC internal dynamics and that A + is a powerful dynamical clock.
Benelli, Giovanni; Otranto, Domenico; Caselli, Alice; Romano, Donato; Remorini, Damiano; Di Giuseppe, Graziano; Stefanini, Cesare; Mele, Marcello; Canale, Angelo
2018-06-01
Calliphora vomitoria is a myiasis-causing fly in many animal species including humans. The control of blowflies is still anchored on the use of chemicals. However, mass trapping and lure-and-kill techniques represent a promising alternative to pesticides. Visual and olfactory cues are the main stimuli routing the fly's landing behavior. Notably, color attractiveness has been barely explored in flies of medical and veterinary importance, with special reference to blowflies. In this study, we investigated the innate color preferences in C. vomitoria adults, testing binary combinations of painted targets under laboratory conditions. The identity of tested species C. vomitoria was confirmed by DNA sequencing (18S and cox1 genes). C. vomitoria flies showed a significant preference for black colored targets in all tested binary color combinations, after 5, 15, 30 and 60 min of exposure. Black targets were significantly preferred over blue, red, yellow and white ones. Spectral characteristics of all tested color combinations were quantified and the innate attraction of blowflies towards black targets was discussed in relation to their behavioral ecology. To the best of our knowledge, this is the first report on innate color preferences in the Calliphora genus. Our findings can be useful to develop new, cheap and reliable monitoring traps as well as "lure and kill" tools to control blowfly pests. Copyright © 2018 Elsevier B.V. All rights reserved.
Cna'ani, Alon; Mühlemann, Joelle K; Ravid, Jasmin; Masci, Tania; Klempien, Antje; Nguyen, Thuong T H; Dudareva, Natalia; Pichersky, Eran; Vainstein, Alexander
2015-07-01
Increasing temperatures due to changing global climate are interfering with plant-pollinator mutualism, an interaction facilitated mainly by floral colour and scent. Gas chromatography-mass spectroscopy analyses revealed that increasing ambient temperature leads to a decrease in phenylpropanoid-based floral scent production in two Petunia × hybrida varieties, P720 and Blue Spark, acclimated at 22/16 or 28/22 °C (day/night). This decrease could be attributed to down-regulation of scent-related structural gene expression from both phenylpropanoid and shikimate pathways, and up-regulation of a negative regulator of scent production, emission of benzenoids V (EOBV). To test whether the negative effect of increased temperature on scent production can be reduced in flowers with enhanced metabolic flow in the phenylpropanoid pathway, we analysed floral volatile production by transgenic 'Blue Spark' plants overexpressing CaMV 35S-driven Arabidopsis thaliana production of anthocyanin pigments 1 (PAP1) under elevated versus standard temperature conditions. Flowers of 35S:PAP1 transgenic plants produced the same or even higher levels of volatiles when exposed to a long-term high-temperature regime. This phenotype was also evident when analysing relevant gene expression as inferred from sequencing the transcriptome of 35S:PAP1 transgenic flowers under the two temperature regimes. Thus, up-regulation of transcription might negate the adverse effects of temperature on scent production. © 2014 John Wiley & Sons Ltd.
Spectroscopy of dwarf elliptical galaxies in the Fornax cluster
NASA Technical Reports Server (NTRS)
Held, Enrico V.; Mould, Jeremy R.
1994-01-01
We present the results of spectroscopic observations of 10 nucleated dwarf elliptical galaxies (dE's) in the Fornax cluster. The blue spectra of Fornax dE galaxies indicate a wide range of metallicities at a given luminosity, similar to those of intermediate to metal-rich globular clusters. Metal abundances derived in this paper are well correlated with optical colors and agree with previous spectroscopic results. A discrepancy with metallicities inferred from infrared colors is evident; possible causes include an intermediate age population and dilution of spectral features by a blue light excess. Dwarf ellipticals exhibit a wide variation of hydrogen line strength which points to a complex star formation history. Prominent Balmer absorption lines are the signature of a young stellar population in the nuclei of some (but not all) dE's, while moderately strong Balmer lines in relatively metal-rich dE's are more consistent with an extended main sequence. In a few metal-poor dE galaxies, the hydrogen lines are consisent with, or perhaps weaker than, those found in Galactic globulars of similar metallicity. In the limited magnitude range of this sample, there is no apparent correlation of metallicity either with effective and central surface brightness, or with total and nuclear magnitudes. The velocity distribution of the Fornax dwarfs is flatter than that of brighter galaxies at the 75% confidence level, possibly indicating a difference in the kinematics of the two samples.
Menkis, A; Lynikienė, J; Marčiulynas, A; Gedminas, A; Povilaitienė, A
2017-08-01
We studied the occurrence, morphology and phenology of Dendroctonus micans in Lithuania and the fungi associated with the beetle at different developmental stages. The occurrence of D. micans was assessed in 19 seed orchards (at least 40 years old) of Picea abies (L. Karst.) situated in different parts of the country. Bark beetle phenology was studied in two sites: a seed orchard of P. abies and a plantation of Picea pungens (Engelm.). D. micans morphology was assessed under the dissection microscope using individuals at different developmental stages that were sampled during phenology observations. Communities of fungi associated with D. micans were studied using both fungal culturing methods and direct high-throughput sequencing from D. micans. Results showed that the incidence D. micans was relatively rare and D. micans was mainly detected in central and eastern Lithuania. The life cycle included the following stages: adult, egg, I-V developmental stage larvae and pupa. However, development of D. micans was quicker and its nests larger under the bark of P. pungens than of P. abies, indicating the effect of the host species. Fungal culturing and direct high-throughput sequencing revealed that D. micans associated fungi communities were species rich and dominated by yeasts from a class Saccharomycetes. In total, 319 fungal taxa were sequenced, among which Peterozyma toletana (37.5% of all fungal sequences), Yamadazyma scolyti (30.0%) and Kuraishia capsulate (17.7%) were the most common. Plant pathogens and blue stain fungi were also detected suggesting their potentially negative effects to both tree health and timber quality.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Goncalves, Thiago S.; Menendez-Delmestre, Karin; Martin, D. Christopher
2012-11-01
The bimodality in galaxy properties has been observed at low and high redshifts, with a clear distinction between star-forming galaxies in the blue cloud and passively evolving objects in the red sequence; the absence of galaxies with intermediate properties indicates that the quenching of star formation and subsequent transition between populations must happen rapidly. In this paper, we present a study of over 100 transiting galaxies in the so-called green valley at intermediate redshifts (z {approx} 0.8). By using very deep spectroscopy with the DEIMOS instrument at the Keck telescope we are able to infer the star formation histories ofmore » these objects and measure the stellar mass flux density transiting from the blue cloud to the red sequence when the universe was half its current age. Our results indicate that the process happened more rapidly and for more massive galaxies in the past, suggesting a top-down scenario in which the massive end of the red sequence is forming first. This represents another aspect of downsizing, with the mass flux density moving toward smaller galaxies in recent times.« less
ERIC Educational Resources Information Center
Tarr, C. Anita
1997-01-01
Argues that, in "Island of the Blue Dolphins," Scott O'Dell offers a skeleton main character (Karana). Contends that O'Dell has sketched Karana as a stereotype and that readers complete her characterization, filling out the skeleton by perpetuating the stereotypes. Points out this trading of stereotype for true character development in…
Liu, Lijie; Wang, Xiang; Wang, Nan; Peng, Tai; Wang, Suning
2017-07-24
A new class of highly efficient and stable, blue-phosphorescent Pt II complexes based on a tetradentate chelating framework has been found to exhibit highly sensitive and reversible responses to multiple external stimuli including temperature, pressure, and UV irradiation with distinct phosphorescent color switching-from blue to red or white. Intermolecular excimer formation is the main origin of this intriguing multi-response phenomenon. Highly efficient singlet-oxygen sensitization by the Pt II compounds yields UV-light-induced phosphorescence enhancement and color switching. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
3D Laser Scanner Data Collection
2007-09-01
advertising , publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such...of Temperate Site D depicting vegetation height in meters. The image portrays a chromatic sequence with lower vegetation heights appearing blue and
Using Blue Stragglers to Predict Retained Black Hole Population in Globular Clusters
NASA Astrophysics Data System (ADS)
Hermanek, Keith; Chatterjee, Sourav; Rasio, Frederic
2018-01-01
Large numbers of black holes (BHs) are expected to form in massive star clusters typical of the globular clusters (GCs). Sophisticated theoretical models suggest that many of these BHs can be retained in present-day GCs. Observations have also identified several BH candidates in Galactic and extragalactic GCs (e.g., Macarone et al. 2007; Irwin et al. 2010; Strader et al. 2012; Chomiuk et al. 2013; Miller-Jones et al. 2014). It has also been shown that high-mass and high-density clusters such as GCs are efficient factories of merging binary BHs similar to those observed by the LIGO observatories (Abbott et al. 2016a,b,c,d,e; Rodriguez et al. 2016). Understanding the formation rate and properties of binary BHs are dependent on a detailed understanding of how the BHs dynamically evolve within GCs. Nevertheless, directly detecting BHs in GCs is extremely challenging; BHs only in binaries with limited configurations can be directly detected by the detection of gravitational wave, X-ray, or radio emissions. We propose an indirect of inferring the number of undetected retained BHs in a GC by investigating the dynamical effects of a large number of BHs on the production of other tracer populations such as Blue Straggler Stars (BSS). Using a large grid of detailed GC models we show that there is a clear anti-correlation between the number of BSS in a cluster and the number of retained BHs. Being the most massive species, large numbers of retained BHs will dominate the core of the cluster as a result of mass-segregation driving away other low-mass species such as main-sequence stars from central high-density regions. BSS are expected to form from physical collisions between main-sequence (MS) stars mediated by binary encounters (e.g., Chatterjee et al. 2013) in cores of GCs. Production of BSS by collisions or mass transfer channels are suppressed if a large number of retained BHs in a cluster restrict the number of MS stars in the core. Extensive observational data exist on the number and radial distribution of BSS in GCs. Thus, this anti-correlation between the number of retained BHs and the number of BSS, once carefully calibrated by theoretical models, can be used to infer the population of undetected BHs in GCs.
Hao, Yan; Saygili, Yasemin; Cong, Jiayan; Eriksson, Anna; Yang, Wenxing; Zhang, Jinbao; Polanski, Enrico; Nonomura, Kazuteru; Zakeeruddin, Shaik Mohammed; Grätzel, Michael; Hagfeldt, Anders; Boschloo, Gerrit
2016-12-07
Blue and green dyes as well as NIR-absorbing dyes have attracted great interest because of their excellent ability of absorbing the incident photons in the red and near-infrared range region. A novel blue D-π-A dye (Dyenamo Blue), based on the diketopyrrolopyrrole (DPP)-core, has been designed and synthesized. Assembled with the cobalt bipyridine-based electrolytes, the device with Dyenamo Blue achieved a satisfying efficiency of 7.3% under one sun (AM1.5 G). The co-sensitization strategy was further applied on this blue organic dye together with a red D-π-A dye (D35). The successful co-sensitization outperformed a panchromatic light absorption and improved the photocurrent density; this in addition to the open-circuit potential result in an efficiency of 8.7%. The extended absorption of the sensitization and the slower recombination reaction between the blue dye and TiO 2 surface inhibited by the additional red sensitizer could be the two main reasons for the higher performance. In conclusion, from the results, the highly efficient cobalt-based DSSCs could be achieved with the co-sensitization between red and blue D-π-A organic dyes with a proper design, which showed us the possibility of applying this strategy for future high-performance solar cells.
Effects of blue light and caffeine on mood.
Ekström, Johan G; Beaven, C Martyn
2014-09-01
Both short wavelength (blue) light and caffeine have been studied for their mood enhancing effects on humans. The ability of blue light to increase alertness, mood and cognitive function via non-image forming neuropathways has been suggested as a non-pharmacological countermeasure for depression across a range of occupational settings. This experimental study compared blue light and caffeine and aimed to test the effects of blue light/placebo (BLU), white light/240-mg caffeine (CAF), blue light/240-mg caffeine (BCAF) and white light/placebo (PLA), on mood. A randomised, controlled, crossover design study was used, in a convenience population of 20 healthy volunteers. The participants rated their mood on the Swedish Core Affect Scales (SCAS) prior to and after each experimental condition to assess the dimensions of valence and activation. There was a significant main effect of light (p = 0.009), and the combination of blue light and caffeine had clear positive effects on core effects (ES, ranging from 0.41 to 1.20) and global mood (ES, 0.61 ± 0.53). The benefits of the combination of blue light and caffeine should be further investigated across a range of applications due to the observed effects on the dimensions of arousal, valence and pleasant activation.
Evaluation of blue and green water resources in the upper Yellow River basin of China
NASA Astrophysics Data System (ADS)
Gao, Xiaoxi; Zuo, Depeng; Xu, Zongxue; Cai, Siyang; Xianming, Han
2018-06-01
The total amount of water resources severely affects socioeconomic development of a region or watershed, which means that accurate quantification of the total amount of water resources is vital for the area, especially for the arid and semi-arid regions. Traditional evaluation of water resources only focused on the qualification of blue water, while the importance of green water was not fully considered. As the second largest river in China, the Yellow River plays an important role in socioeconomic development of the Yellow River basin. Therefore, the blue and green water resources in the upper Yellow River basin (UYRB) were evaluated by the SWAT model in this study. The results show that the average annual total amount of water resources in the UYRB was 140.5 billion m3, in which the blue water resources is 37.8 billion m3, and green water resources is 107.7 billion m3. The intra-annual variability of the blue water and green water is relatively similar during the same period. The higher temperature, the greater difference between the blue and green water. The inter-annual variability of the blue and green water shows that the trends in precipitation, blue and green water have a relatively similar characteristic. The spatial distribution of the blue and green water is characteristic with gradually decreasing from the northwest to the southeast, and the blue water around the main stream is greater than that in the other areas.
Xie, Chunliang; Gong, Wenbing; Zhu, Zuohua; Yan, Li; Hu, Zhenxiu; Peng, Yuande
2018-05-01
Blue light is an important environmental factor which could induce mushroom primordium differentiation and fruiting body development. However, the mechanisms of Pleurotus eryngii primordium differentiation and development induced by blue light are still unclear. The CAZymes (carbohydrate-active enzymes) play important roles in degradation of renewable lignocelluloses to provide carbohydrates for fungal growth, development and reproduction. In the present research, the expression profiles of genes were measured by comparison between the Pleurotus eryngii at primordium differentiated into fruiting body stage after blue light stimulation and dark using high-throughput sequencing approach. After assembly and compared to the Pleurotus eryngii reference genome, 11,343 unigenes were identified. 539 differentially expressed genes including white collar 2 type of transcription factor gene, A mating type protein gene, MAP kinase gene, oxidative phosphorylation associated genes, CAZymes genes and other metabolism related genes were identified during primordium differentiated into fruiting body stage after blue light stimulation. KEGG results showed that carbon metabolism, glycolysis/gluconeogenesis and biosynthesis of amino acids pathways were affected during blue light inducing primordia formation. Most importantly, 319 differentially expressed CAZymes participated in carbon metabolism were identified. The expression patterns of six representative CAZymes and laccase genes were further confirmed by qRT-PCR. Enzyme activity results indicated that the activities of CAZymes and laccase were affected in primordium differentiated into fruiting body under blue light stimulation. In conclusion, the comprehensive transcriptome and CAZymes of Pleurotus eryngii at primordium differentiated into fruiting body stage after blue light stimulation were obtained. The biological insights gained from this integrative system represent a valuable resource for future genomic studies on this commercially important mushroom. Copyright © 2017. Published by Elsevier Inc.
75 FR 10814 - National Register of Historic Places; Weekly Listing of Historic Properties
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-09
..., LISTED, 12/18/09 (Newton MRA) Plymouth County Marshfield Hills HD, Bow, Highland, Main, Old Main... MINNESOTA Blue Earth County Mapleton Public Library, 104 1st. Ave. NE, Mapleton, 09001097, LISTED, 12/18/09...
NASA Astrophysics Data System (ADS)
Bower, Richard G.; Schaye, Joop; Frenk, Carlos S.; Theuns, Tom; Schaller, Matthieu; Crain, Robert A.; McAlpine, Stuart
2017-02-01
Galaxies fall into two clearly distinct types: `blue-sequence' galaxies which are rapidly forming young stars, and `red-sequence' galaxies in which star formation has almost completely ceased. Most galaxies more massive than 3 × 1010 M⊙ follow the red sequence, while less massive central galaxies lie on the blue sequence. We show that these sequences are created by a competition between star formation-driven outflows and gas accretion on to the supermassive black hole at the galaxy's centre. We develop a simple analytic model for this interaction. In galaxies less massive than 3 × 1010 M⊙, young stars and supernovae drive a high-entropy outflow which is more buoyant than any tenuous corona. The outflow balances the rate of gas inflow, preventing high gas densities building up in the central regions. More massive galaxies, however, are surrounded by an increasingly hot corona. Above a halo mass of ˜1012 M⊙, the outflow ceases to be buoyant and star formation is unable to prevent the build-up of gas in the central regions. This triggers a strongly non-linear response from the black hole. Its accretion rate rises rapidly, heating the galaxy's corona, disrupting the incoming supply of cool gas and starving the galaxy of the fuel for star formation. The host galaxy makes a transition to the red sequence, and further growth predominantly occurs through galaxy mergers. We show that the analytic model provides a good description of galaxy evolution in the EAGLE hydrodynamic simulations. So long as star formation-driven outflows are present, the transition mass scale is almost independent of subgrid parameter choice.
Origin of the blue shift of the CH stretching band for 2-butoxyethanol in water.
Katsumoto, Yukiteru; Komatsu, Hiroyuki; Ohno, Keiichi
2006-07-26
The blue shift of the isolated CD stretching band of 2-butoxyethanol (C4E1), which is observed for the aqueous solution during the dilution process, has been investigated by infrared (IR) spectroscopy and quantum chemical calculations. Mono-deuterium-labeled C4E1's were employed to remove the severe overlapping among the CH stretching bands. The isolated CD stretching mode of the alpha-methylene in the butoxy group shows a large blue shift, while those of the beta-methylene and methyl groups are not largely shifted. The spectral simulation results for the C4E1/H2O complexes indicate that the large blue shift of the CD stretching band of the butoxy group arises mainly from the hydration of the ether oxygen atom.
Blue Corn Tortillas: Effects on Learning and Spatial Memory in Rats.
Aguirre López, L O; Chávez Servia, J L; Gómez Rodiles, C C; Beltrán Ramírez, J R; Bañuelos Pineda, J
2017-12-01
Consumption of pigmented corn has been associated with health benefits due to its flavonoid contents (mainly anthocyanins) and antioxidant ability. Therefore, the objective of this study was to determine the effect of blue corn tortilla (BM) consumption on memory and learning ability adult rats. Eighteen adult female rats were divided into three groups and fed for 38 consecutive days with commercial food (Control group) or the commercial food plus 6 g/day of either blue corn (BM) or white corn (WM) tortillas. Memory and learning capabilities were assessed using Barnes's labyrinth at the end of the feeding period. Short-and long-term memory was improved in the BM group, showing that consumption of blue maize tortillas improves learning and memory capabilities in adult rats.
Galaxy luminosity function: evolution at high redshift
NASA Astrophysics Data System (ADS)
Martinet, N.; Durret, F.; Guennou, L.; Adami, C.
2014-12-01
There are some disagreements about the abundance of faint galaxies in high redshift clusters. DAFT/FADA (Dark energy American French Team) is a medium redshift (0.4
Endogenous Retrovirus EAV-HP Linked to Blue Egg Phenotype in Mapuche Fowl
Alcalde, José A.; Wang, Chen; Han, Jian-Lin; Gongora, Jaime; Gourichon, David; Tixier-Boichard, Michèle; Hanotte, Olivier
2013-01-01
Oocyan or blue/green eggshell colour is an autosomal dominant trait found in native chickens (Mapuche fowl) of Chile and in some of their descendants in European and North American modern breeds. We report here the identification of an endogenous avian retroviral (EAV-HP) insertion in oocyan Mapuche fowl and European breeds. Sequencing data reveals 100% retroviral identity between the Mapuche and European insertions. Quantitative real-time PCR analysis of European oocyan chicken indicates over-expression of the SLCO1B3 gene (P<0.05) in the shell gland and oviduct. Predicted transcription factor binding sites in the long terminal repeats (LTR) indicate AhR/Ar, a modulator of oestrogen, as a possible promoter/enhancer leading to reproductive tissue-specific over-expression of the SLCO1B3 gene. Analysis of all jungle fowl species Gallus sp. supports the retroviral insertion to be a post-domestication event, while identical LTR sequences within domestic chickens are in agreement with a recent de novo mutation. PMID:23990950
Endogenous retrovirus EAV-HP linked to blue egg phenotype in Mapuche fowl.
Wragg, David; Mwacharo, Joram M; Alcalde, José A; Wang, Chen; Han, Jian-Lin; Gongora, Jaime; Gourichon, David; Tixier-Boichard, Michèle; Hanotte, Olivier
2013-01-01
Oocyan or blue/green eggshell colour is an autosomal dominant trait found in native chickens (Mapuche fowl) of Chile and in some of their descendants in European and North American modern breeds. We report here the identification of an endogenous avian retroviral (EAV-HP) insertion in oocyan Mapuche fowl and European breeds. Sequencing data reveals 100% retroviral identity between the Mapuche and European insertions. Quantitative real-time PCR analysis of European oocyan chicken indicates over-expression of the SLCO1B3 gene (P<0.05) in the shell gland and oviduct. Predicted transcription factor binding sites in the long terminal repeats (LTR) indicate AhR/Ar, a modulator of oestrogen, as a possible promoter/enhancer leading to reproductive tissue-specific over-expression of the SLCO1B3 gene. Analysis of all jungle fowl species Gallus sp. supports the retroviral insertion to be a post-domestication event, while identical LTR sequences within domestic chickens are in agreement with a recent de novo mutation.
Farjami, Elaheh; Clima, Lilia; Gothelf, Kurt V; Ferapontova, Elena E
2010-06-01
A DNA molecular beacon approach was used for the analysis of interactions between DNA and Methylene Blue (MB) as a redox indicator of a hybridization event. DNA hairpin structures of different length and guanine (G) content were immobilized onto gold electrodes in their folded states through the alkanethiol linker at the 5'-end. Binding of MB to the folded hairpin DNA was electrochemically studied and compared with binding to the duplex structure formed by hybridization of the hairpin DNA to a complementary DNA strand. Variation of the electrochemical signal from the DNA-MB complex was shown to depend primarily on the DNA length and sequence used: the G-C base pairs were the preferential sites of MB binding in the duplex. For short 20 nts long DNA sequences, the increased electrochemical response from MB bound to the duplex structure was consistent with the increased amount of bound and electrochemically readable MB molecules (i.e. MB molecules that are available for the electron transfer (ET) reaction with the electrode). With longer DNA sequences, the balance between the amounts of the electrochemically readable MB molecules bound to the hairpin DNA and to the hybrid was opposite: a part of the MB molecules bound to the long-sequence DNA duplex seem to be electrochemically mute due to long ET distance. The increasing electrochemical response from MB bound to the short-length DNA hybrid contrasts with the decreasing signal from MB bound to the long-length DNA hybrid and allows an "off"-"on" genosensor development.
DETAIL OF EAST (CANADIAN) CANTILEVER AND ANCHOR ARMS OF MAIN ...
DETAIL OF EAST (CANADIAN) CANTILEVER AND ANCHOR ARMS OF MAIN SPAN, SHOWING PIER C. VIEW TO NORTH. - Blue Water Bridge, Spanning St. Clair River at I-69, I-94, & Canadian Route 402, Port Huron, St. Clair County, MI
EAST (CANADIAN) PORTAL OF MAIN SECTION OF BRIDGE, SHOWING PANEL ...
EAST (CANADIAN) PORTAL OF MAIN SECTION OF BRIDGE, SHOWING PANEL OVER PIER C IN CENTER. VIEW TO WEST. - Blue Water Bridge, Spanning St. Clair River at I-69, I-94, & Canadian Route 402, Port Huron, St. Clair County, MI
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bellini, A.; Anderson, J.; Marel, R. P. van der
2015-09-01
Numerous observational studies have revealed the ubiquitous presence of multiple stellar populations in globular clusters and cast many difficult challenges for the study of the formation and dynamical history of these stellar systems. In this Letter we present the results of a study of the kinematic properties of multiple populations in NGC 2808 based on high-precision Hubble Space Telescope proper-motion measurements. In a recent study, Milone et al. identified five distinct populations (A–E) in NGC 2808. Populations D and E coincide with the helium-enhanced populations in the middle and the blue main sequences (mMS and bMS) previously discovered by Piottomore » et al.; populations A–C correspond to the redder main sequence that, in Piotto et al., was associated with the primordial stellar population. Our analysis shows that, in the outermost regions probed (between about 1.5 and 2 times the cluster half-light radius), the velocity distribution of populations D and E is radially anisotropic (the deviation from an isotropic distribution is significant at the ∼3.5σ level). Stars of populations D and E have a smaller tangential velocity dispersion than those of populations A–C, while no significant differences are found in the radial velocity dispersion. We present the results of a numerical simulation showing that the observed differences between the kinematics of these stellar populations are consistent with the expected kinematic fingerprint of the diffusion toward the cluster outer regions of stellar populations initially more centrally concentrated.« less
A New Sample of Cool Subdwarfs from SDSS: Properties and Kinematics
NASA Astrophysics Data System (ADS)
Savcheva, Antonia; West, Andrew A.; Bochanski, John J.
2014-06-01
We present a new sample of M subdwarfs compiled from the 7th data re- lease of the Sloan Digital Sky Survey. With 3517 new subdwarfs, this new sample significantly increases the number the existing sample of low-mass subdwarfs. This catalog includes unprecedentedly large numbers of extreme and ultra sudwarfs. Here, we present the catalog and the statistical analysis we perform. Subdwarf template spectra are derived. We show color-color and reduced proper motion diagrams of the three metallicity classes, which are shown to separate from the disk dwarf population. The extreme and ultra subdwarfs are seen at larger values of reduced proper motion as expected for more dynamically heated populations. We determine 3D kinematics for all of the stars with proper motions. The color-magnitude diagrams show a clear separation of the three metallicity classes with the ultra and extreme subdwarfs being significantly closer to the main sequence than the ordinary subdwarfs. All subdwarfs lie below and to the blue of the main sequence. Based on the average (U, V, W ) velocities and their dispersions, the extreme and ultra subdwarfs likely belong to the Galactic halo, while the ordinary subdwarfs are likely part of the old Galactic (or thick) disk. An extensive activity analy- sis of subdwarfs is performed using chromospheric Hα emission and 208 active subdwarfs are found. We show that while the activity fraction of subdwarfs rises with spectral class and levels off at the latest spectral classes, consistent with the behavior of M dwarfs, the extreme and ultra subdwarfs are basically flat.
Anticipatory effects of intonation: Eye movements during instructed visual search
Ito, Kiwako; Speer, Shari R
2007-01-01
Three eye-tracking experiments investigated the role of pitch accents during online discourse comprehension. Participants faced a grid with ornaments, and followed pre-recorded instructions such as “Next, hang the blue ball” to decorate holiday trees. Experiment 1 demonstrated a processing advantage for felicitous as compared to infelicitous uses of L+H* on the adjective noun pair (e.g. blue ball followed by GREEN ball vs. green BALL). Experiment 2 confirmed that L+H* on a contrastive adjective led to ‘anticipatory’ fixations, and demonstrated a “garden path” effect for infelicitous L+H* in sequences with no discourse contrast (e.g. blue angel followed by GREEN ball resulted in erroneous fixations to the cell of angels). Experiment 3 examined listeners’ sensitivity to coherence between pitch accents assigned to discourse markers such as ‘And then,’ and those assigned to the target object noun phrase. PMID:19190719
Hippo in Super Resolution from Super Panorama
1998-07-03
This view of the "Hippo," 25 meters to the west of the lander, was produced by combining the "Super Panorama" frames from the IMP camera. Super resolution was applied to help to address questions about the texture of this rock and what it might tell us about its mode of origin. The composite color frames that make up this anaglyph were produced for both the right and left eye of the IMP. These composites consist of more than 15 frames per eye (because multiple sequences covered the same area), taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be. These panchromatic frames were then colorized with the red, green, and blue filtered images from the same sequence. The color balance was adjusted to approximate the true color of Mars. The anaglyph view was produced by combining the left with the right eye color composite frames by assigning the left eye composite view to the red color plane and the right eye composite view to the green and blue color planes (cyan), to produce a stereo anaglyph mosaic. This mosaic can be viewed in 3-D on your computer monitor or in color print form by wearing red-blue 3-D glasses. http://photojournal.jpl.nasa.gov/catalog/PIA01421
Wang, Xiao-Jing; Wang, Xiao-Xing; Wang, Ya-Jun; Wang, Xi-Zhong; He, Guang-Xin; Chen, Hong-Wei; Fei, Li-Song
2002-09-01
Activin, which is included in the transforming growth factor-beta (TGF beta) superfamily of proteins and receptors, is known to have broad-ranging effects in the creatures. The mature peptide of beta A subunit of this gene, one of the most highly conserved sequence, can elevate the basal secretion of follicle-stimulating hormone (FSH) in the pituitary and FSH is pivotal to organism's reproduction. Reproduction block is one of the main reasons which cause giant panda to extinct. The sequence of Activin beta A subunit gene mature peptides has been successfully amplified from giant panda, red panda and malayan sun bear's genomic DNA by using polymerase chain reaction (PCR) with a pair of degenerate primers. The PCR products were cloned into the vector pBlueScript+ of Esherichia coli. Sequence analysis of Activin beta A subunit gene mature peptides shows that the length of this gene segment is the same (359 bp) and there is no intron in all three species. The sequence encodes a peptide of 119 amino acid residues. The homology comparison demonstrates 93.9% DNA homology and 99% homology in amino acid among these three species. Both GenBank blast search result and restriction enzyme map reveal that the sequences of Activin beta A subunit gene mature peptides of different species are highly conserved during the evolution process. Phylogeny analysis is performed with PHYLIP software package. A consistent phylogeny tree has been drawn with three different methods. The software analysis outcome accords with the academic view that giant panda has a closer relationship to the malayan sun bear than the red panda. Giant panda should be grouped into the bear family (Uersidae) with the malayan sun bear. As to the red panda, it would be better that this animal be grouped into the unique family (red panda family) because of great difference between the red panda and the bears (Uersidae).
Galland, Paul; Tölle, Nadja
2003-10-01
Light-induced fluorescence changes (LIFCs) were detected in sporangiophores of the blue-light-sensitive fungus Phycomyces blakesleeanus (Burgeff). The LIFCs can be utilized as a spectrophotometric assay for blue-light photoreceptors and for the in vivo characterization of their photochemical primary reactions. Blue-light irradiation of sporangiophores elicited a transient decrease and subsequent regeneration of flavin-like fluorescence emission at 525 nm. The signals recovered in darkness in about 120 min. In contrast to blue light, near-UV (370 nm) caused an increase in the fluorescence emission at 525 nm. Because the LIFCs were altered in a light-insensitive madC mutant with a defective photoreceptor, the fluorescence changes must be associated with early photochemical events of the transduction chain. Action spectra for the fluorescence changes at 525 nm showed major peaks near 470 and 600 nm. Double-pulse experiments involving two consecutive pulses of either blue and near-UV, blue and red, or near-UV and red showed that the responses depended on the sequence in which the different wavelengths were applied. The results indicate a blue-light receptor with intermediates in the near-UV, blue and red spectral regions. We explain the results in the framework of a general model, in which the three redox states of the flavin photoreceptor, the oxidized flavin (Fl), the flavo-semiquinone (FlH*), and the flavo-hydroquinone (FlH2) are each acting as chromophores with their own characteristic photochemical primary reactions. These consist of the photoreduction of the oxidized flavin generating semiquinone, the photoreduction of the semiquinone generating hydroquinone, and the photooxidation of the flavo-hydroquinone regenerating the pool of oxidized flavins. The proposed mechanism represents a photocycle in which two antagonistic photoreceptor forms, Fl and FlH2, determine the pool size of the biological effector molecule, the flavo-semiquinone. The redox changes that are associated with the photocycle are maintained by redox partners, pterins, that function in the near-UV as secondary chromophores.
Anthocyanin Profiles in Flowers of Grape Hyacinth.
Lou, Qian; Wang, Lin; Liu, Hongli; Liu, Yali
2017-04-26
Grape hyacinth ( Muscari spp.) is a popular ornamental bulbous perennial famous for its blue flowers. To understand the chemical basis of the rich blue colors in this plant, anthocyanin profiles of six blue flowering grape hyacinths as well as one pink and one white cultivar were determined using high-performance liquid chromatography and mass spectrometry. Along with two known compounds, eight putative anthocyanins were identified in the tepals of grape hyacinth for the first time. The accumulation and distribution of anthocyanins in the plant showed significant cultivar and flower development specificity. Violet-blue flowers mainly contained simple delphinidin-type anthocyanins bearing one or two methyl-groups but no acyl groups, whereas white and pink flowers synthesised more complex pelargonidin/cyanidin-derivatives with acyl-moieties but no methyl-groups. The results partially reveal why solid blue, orange or red flowers are rare in this plant in nature. In addition, pelargonidin-type anthocyanins were found for the first time in the genus, bringing more opportunities in terms of breeding of flower color in grape hyacinth.
A developmental study of the acquisition of Russian colour terms.
Davies, I R; Corbett, G G; McGurk, H; MacDermid, C
1998-06-01
We report a study of the acquisition of colour terms by Russian children which had two main aims: first, to test Berlin & Kay's (1969) theory of colour universals using acquisition order as a measure of basicness; and secondly, to see if the two BLUE terms of Russian are genuinely basic. Two hundred children aged from three to six-years-old were tested on three colour-tasks--colour term listing, colour term production and colour term comprehension. To a reasonable approximation, the order of colour term acquisition was in accord with Berlin & Kay's theory, but the data are also consistent with the weaker claim that primary terms tend to be learned before derived terms. On balance the data were consistent with Russian exceptionally, having an extra term for the BLUE region. But, the two BLUE terms--goluboj 'light blue' and sinij 'dark blue'--were confused more often than other pairs of terms even by the five- to six-year-old sample.
Effect on in vitro starch digestibility of Mexican blue maize anthocyanins.
Camelo-Méndez, Gustavo A; Agama-Acevedo, Edith; Sanchez-Rivera, Mirna M; Bello-Pérez, Luis A
2016-11-15
The purpose of this study was to evaluate the effect of blue maize extracts obtained by acid-methanol treatment on the nutritional in vitro starch fractions such as: rapidly digestive starch (RDS), slowly digestive starch (SDS) and resistant starch (RS) of native and gelatinized commercial maize starch. Chromatographic analysis (HPLC-DAD/ESI-MS) of blue maize extracts showed the presence of seven anthocyanins, where cyanidin-3-(6″-malonylglucoside) was the main. Blue maize extracts modified nutritional in vitro starch fractions (decrease of RDS) while RS content increased (1.17 and 2.02 times for native and gelatinized commercial maize starch, respectively) when anthocyanins extracts were added to starch up to 75% (starch weight). This preliminary observation provides the basis for further suitability evaluation of blue maize extract as natural starch-modifier by the possible anthocyanins-starch interaction. Anthocyanin extracts can be a suitable to produce functional foods with higher RS content with potential human health benefits. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Sunar, N. M.; Mon, Z. K.; Rahim, N. A.; Leman, A. M.; Airish, N. A. M.; Khalid, A.; Ali, R.; Zaidi, E.; Azhar, A. T. S.
2018-04-01
Wastewater released from the textile industry contains variety substances, mainly dyes that contains a high concentration of color and organic. In this study the potential for bacterial decolorization of coractive blue dye was examined that isolated from textile wastewater. The optimum conditions were determined for pH, temperature and initial concentration of the dye. The bacteria isolated was Pseudomonas spp. The selected bacterium shows high decolorization in static condition at an optimum of pH 7.0. The Pseudomonas spp. could decolorize coractive blue dye by 70% within 24 h under static condition, with the optimum of pH 7.0. Decolorization was confirmed by using UV-VIS spectrophotometer. This present study suggests the potential of Pseudomonas spp. as an approach in sustainable bioremediation that provide an efficient method for decolorizing coractive blue dye.
NASA Astrophysics Data System (ADS)
Ogle, Patrick M.; Lanz, Lauranne; Nader, Cyril; Helou, George
2016-02-01
We report the discovery of spiral galaxies that are as optically luminous as elliptical brightest cluster galaxies, with r-band monochromatic luminosity Lr = 8-14L* (4.3-7.5 × 1044 erg s-1). These super spiral galaxies are also giant and massive, with diameter D = 57-134 kpc and stellar mass Mstars = 0.3-3.4 × 1011M⊙. We find 53 super spirals out of a complete sample of 1616 SDSS galaxies with redshift z < 0.3 and Lr > 8L*. The closest example is found at z = 0.089. We use existing photometry to estimate their stellar masses and star formation rates (SFRs). The SDSS and Wide-field Infrared Survey Explorer colors are consistent with normal star-forming spirals on the blue sequence. However, the extreme masses and rapid SFRs of 5-65 M⊙ yr-1 place super spirals in a sparsely populated region of parameter space, above the star-forming main sequence of disk galaxies. Super spirals occupy a diverse range of environments, from isolation to cluster centers. We find four super spiral galaxy systems that are late-stage major mergers—a possible clue to their formation. We suggest that super spirals are a remnant population of unquenched, massive disk galaxies. They may eventually become massive lenticular galaxies after they are cut off from their gas supply and their disks fade.
Le Bras, Ronan J; Kuzma, Heidi; Sucic, Victor; Bokelmann, Götz
2016-05-01
A notable sequence of calls was encountered, spanning several days in January 2003, in the central part of the Indian Ocean on a hydrophone triplet recording acoustic data at a 250 Hz sampling rate. This paper presents signal processing methods applied to the waveform data to detect, group, extract amplitude and bearing estimates for the recorded signals. An approximate location for the source of the sequence of calls is inferred from extracting the features from the waveform. As the source approaches the hydrophone triplet, the source level (SL) of the calls is estimated at 187 ± 6 dB re: 1 μPa-1 m in the 15-60 Hz frequency range. The calls are attributed to a subgroup of blue whales, Balaenoptera musculus, with a characteristic acoustic signature. A Bayesian location method using probabilistic models for bearing and amplitude is demonstrated on the calls sequence. The method is applied to the case of detection at a single triad of hydrophones and results in a probability distribution map for the origin of the calls. It can be extended to detections at multiple triads and because of the Bayesian formulation, additional modeling complexity can be built-in as needed.
NASA Astrophysics Data System (ADS)
McEvoy, C. M.; Dufton, P. L.; Evans, C. J.; Kalari, V. M.; Markova, N.; Simón-Díaz, S.; Vink, J. S.; Walborn, N. R.; Crowther, P. A.; de Koter, A.; de Mink, S. E.; Dunstall, P. R.; Hénault-Brunet, V.; Herrero, A.; Langer, N.; Lennon, D. J.; Maíz Apellániz, J.; Najarro, F.; Puls, J.; Sana, H.; Schneider, F. R. N.; Taylor, W. D.
2015-03-01
Context. Model atmosphere analyses have been previously undertaken for both Galactic and extragalactic B-type supergiants. By contrast, little attention has been given to a comparison of the properties of single supergiants and those that are members of multiple systems. Aims: Atmospheric parameters and nitrogen abundances have been estimated for all the B-type supergiants identified in the VLT-FLAMES Tarantula survey. These include both single targets and binary candidates. The results have been analysed to investigate the role of binarity in the evolutionary history of supergiants. Methods: tlusty non-local thermodynamic equilibrium (LTE) model atmosphere calculations have been used to determine atmospheric parameters and nitrogen abundances for 34 single and 18 binary supergiants. Effective temperatures were deduced using the silicon balance technique, complemented by the helium ionisation in the hotter spectra. Surface gravities were estimated using Balmer line profiles and microturbulent velocities deduced using the silicon spectrum. Nitrogen abundances or upper limits were estimated from the N ii spectrum. The effects of a flux contribution from an unseen secondary were considered for the binary sample. Results: We present the first systematic study of the incidence of binarity for a sample of B-type supergiants across the theoretical terminal age main sequence (TAMS). To account for the distribution of effective temperatures of the B-type supergiants it may be necessary to extend the TAMS to lower temperatures. This is also consistent with the derived distribution of mass discrepancies, projected rotational velocities and nitrogen abundances, provided that stars cooler than this temperature are post-red supergiant objects. For all the supergiants in the Tarantula and in a previous FLAMES survey, the majority have small projected rotational velocities. The distribution peaks at about 50 km s-1 with 65% in the range 30 km s-1 ≤ vesini ≤ 60 km s-1. About ten per cent have larger vesini (≥100 km s-1), but surprisingly these show little or no nitrogen enhancement. All the cooler supergiants have low projected rotational velocities of ≤70 km s-1and high nitrogen abundance estimates, implying that either bi-stability braking or evolution on a blue loop may be important. Additionally, there is a lack of cooler binaries, possibly reflecting the small sample sizes. Single-star evolutionary models, which include rotation, can account for all of the nitrogen enhancement in both the single and binary samples. The detailed distribution of nitrogen abundances in the single and binary samples may be different, possibly reflecting differences in their evolutionary history. Conclusions: The first comparative study of single and binary B-type supergiants has revealed that the main sequence may be significantly wider than previously assumed, extending to Teff = 20 000 K. Some marginal differences in single and binary atmospheric parameters and abundances have been identified, possibly implying non-standard evolution for some of the sample. This sample as a whole has implications for several aspects of our understanding of the evolutionary status of blue supergiants. Tables 1, 4, 7 are available in electronic form at http://www.aanda.org
Deep g'r'i'z' GMOS Imaging of the Dwarf Irregular Galaxy Kar 50
NASA Astrophysics Data System (ADS)
Davidge, T. J.
2002-11-01
Images obtained with the Gemini Multi-Object Spectrograph (GMOS) are used to investigate the stellar content and distance of the dwarf irregular galaxy Kar 50. The brightest object is an H II region, and the bright stellar content is dominated by stars with g'-r'<0. The tips of the main sequence and the red giant branch (RGB) are tentatively identified near r'=24.9 and i'=25.5, respectively. The galaxy has a blue integrated color and no significant color gradient, and we conclude that Kar 50 has experienced a recent galaxy-wide episode of star formation. The distance estimated from the brightest blue stars indicates that Kar 50 is behind the M81 group, and this is consistent with the tentative RGB-tip brightness. Kar 50 has a remarkably flat central surface brightness profile, even at wavelengths approaching 1 μm, although there is no evidence of a bar. In the absence of another large star-forming episode, Kar 50 will evolve into a very low surface brightness galaxy. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council of Canada (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Halabi, Ghina M.; El Eid, Mounib F.; Champagne, Arthur
2012-12-10
We present stellar evolutionary sequences of stars in the mass range 5-12 M{sub Sun }, having solar-like initial composition. The stellar models are obtained using updated input physics, including recent rates of thermonuclear reactions. We investigate the effects of a modification of the {sup 14}N(p, {gamma}){sup 15}O reaction rate, as suggested by recent evaluations, on the formation and extension of the blue loops encountered during the evolution of the stars in the above mass range. We find that a reduced {sup 14}N(p, {gamma}){sup 15}O rate, as described in the text, has a striking impact on the physical conditions of burningmore » and mixing during shell hydrogen burning when the blue loops are formed. In particular, we find that the efficiency of shell hydrogen burning is crucial for the formation of an extended blue loop. We show that a significantly reduced {sup 14}N(p, {gamma}){sup 15}O rate affects severely the extension of the blue loops and the time spent by the star in the blue part of the Hertzsprung-Russell diagram in the mass range 5-7 M{sub Sun} if the treatment of convection is based on the Schwarzschild criterion only. In this case, envelope overshooting helps to restore well-extended blue loops as supported by the observations of the Cepheid stars. If core overshooting is included during the core hydrogen and core helium burning phases, the loop formation and its properties depend on how this overshooting is treated for a given stellar mass range, as well as on its efficiency.« less
Galaxy and Mass Assembly (GAMA): ugriz galaxy luminosity functions
NASA Astrophysics Data System (ADS)
Loveday, J.; Norberg, P.; Baldry, I. K.; Driver, S. P.; Hopkins, A. M.; Peacock, J. A.; Bamford, S. P.; Liske, J.; Bland-Hawthorn, J.; Brough, S.; Brown, M. J. I.; Cameron, E.; Conselice, C. J.; Croom, S. M.; Frenk, C. S.; Gunawardhana, M.; Hill, D. T.; Jones, D. H.; Kelvin, L. S.; Kuijken, K.; Nichol, R. C.; Parkinson, H. R.; Phillipps, S.; Pimbblet, K. A.; Popescu, C. C.; Prescott, M.; Robotham, A. S. G.; Sharp, R. G.; Sutherland, W. J.; Taylor, E. N.; Thomas, D.; Tuffs, R. J.; van Kampen, E.; Wijesinghe, D.
2012-02-01
Galaxy and Mass Assembly (GAMA) is a project to study galaxy formation and evolution, combining imaging data from ultraviolet to radio with spectroscopic data from the AAOmega spectrograph on the Anglo-Australian Telescope. Using data from Phase 1 of GAMA, taken over three observing seasons, and correcting for various minor sources of incompleteness, we calculate galaxy luminosity functions (LFs) and their evolution in the ugriz passbands. At low redshift, z < 0.1, we find that blue galaxies, defined according to a magnitude-dependent but non-evolving colour cut, are reasonably well fitted over a range of more than 10 magnitudes by simple Schechter functions in all bands. Red galaxies, and the combined blue plus red sample, require double power-law Schechter functions to fit a dip in their LF faintwards of the characteristic magnitude M* before a steepening faint end. This upturn is at least partly due to dust-reddened disc galaxies. We measure the evolution of the galaxy LF over the redshift range 0.002 < z < 0.5 both by using a parametric fit and by measuring binned LFs in redshift slices. The characteristic luminosity L* is found to increase with redshift in all bands, with red galaxies showing stronger luminosity evolution than blue galaxies. The comoving number density of blue galaxies increases with redshift, while that of red galaxies decreases, consistent with prevailing movement from blue cloud to red sequence. As well as being more numerous at higher redshift, blue galaxies also dominate the overall luminosity density beyond redshifts z≃ 0.2. At lower redshifts, the luminosity density is dominated by red galaxies in the riz bands, and by blue galaxies in u and g.
NASA Astrophysics Data System (ADS)
Wagner, B.; Viehberg, F. A.; Wennrich, V.; Junginger, A.; Kolvenbach, A.; Rethemeyer, J.; Schaebitz, F.; Schmiedl, G. H.
2015-12-01
A 12 m long sediment sequence from Dendi Crater lakes, located on the central Ethiopian Plateau, was analysed with sedimentological and geochemical methods to reconstruct the regional environmental history. Bulk organic carbon samples from 23 horizons throughout the sequence were used for AMS radiocarbon dating and indicate that the sediment sequence spans the last ca. 12 cal kyr BP. Microscope analyses and sedimentological data reveal three tephra layers, of which the most prominent layer with a thickness of ~2 m was deposited at 10.2 cal kyr BP and probably originates from an eruption of the Wenchi crater 12 km to the west of the Dendi lakes. Sedimentological data of the pelagic deposits indicate shifts in erosion and rainfall throughout the record. A decrease in Ca and Sr at 11.6 cal kyr BP is related to the shift of less humid condition during the Younger Dryas (YD) to the return to full humid conditions of the African Humid Period (AHP). Single thin horizons with high carbonate content or high Ti and K imply that short spells of dry conditions and significantly increased rainfall superimpose the generally more humid conditions during the AHP. The end of the AHP is gradual. Relatively stable and less humid conditions characterised the Dendi Crater lakes until around 3.9 cal kyr BP. A highly variable increase in clastic matter over the last 1500 years indicates higher erosion due to short-term variations in precipitation within the Dendi catchment. Overall, the sediment record suggests moderate change of precipitation during the Holocene, which is probably due to their exposed location in the Ethiopian highlands. The data from the Dendi Crater lakes show, in concert with other records from the Nile catchment and the Eastern Mediterranean Sea (EMS), that the Blue Nile provided the main freshwater source for maintaining EMS stratification and sapropel S1 formation between ca. 10.0 and 8.7 cal kyr BP. Subsequent aridification is recorded from equatorial East Africa to the northeastern Mediterranean and peaked with some regional differences between ca. 4.0 and 2.6 cal kyr BP. Significant higher discharge in the Blue Nile hydraulic regime after 2.6 cal kyr BP is probably triggered by more local changes in precipitation, which are tentatively caused by a change in the influence of the Indian Ocean.
The ALMA early science view of FUor/EXor objects - I. Through the looking-glass of V2775 Ori
NASA Astrophysics Data System (ADS)
Zurlo, Alice; Cieza, Lucas A.; Williams, Jonathan P.; Canovas, Hector; Perez, Sebastian; Hales, Antonio; Mužić, Koraljka; Principe, David A.; Ruíz-Rodríguez, Dary; Tobin, John; Zhang, Yichen; Zhu, Zhaohuan; Casassus, Simon; Prieto, Jose L.
2017-02-01
As part of an Atacama Large Millimeter/submillimiter Array (ALMA) survey to study the origin of episodic accretion in young eruptive variables, we have observed the circum-stellar environment of the star V2775 Ori. This object is a very young, pre-main sequence object which displays a large amplitude outburst characteristic of the FUor class. We present Cycle-2 band 6 observations of V2775 Ori with a continuum and CO (2-1) isotopologue resolution of 0.25 arcsec (103 au). We report the detection of a marginally resolved circum-stellar disc in the ALMA continuum with an integrated flux of 106 ± 2 mJy, characteristic radius of ˜30 au, inclination of 14.0^{+7.8}_{-14.5} deg and is oriented nearly face-on with respect to the plane of the sky. The 12CO emission is separated into distinct blue and redshifted regions that appear to be rings or shells of expanding material from quasi-episodic outbursts. The system is oriented in such a way that the disc is seen through the outflow remnant of V2775 Ori, which has an axis along our line of sight. The 13CO emission displays similar structure to that of the 12CO, while the C18O line emission is very weak. We calculated the expansion velocities of the low- and medium-density material with respect to the disc to be of -2.85 (blue), 4.4 (red) and -1.35 and 1.15 km s-1 (for blue and red) and we derived the mass, momentum and kinetic energy of the expanding gas. The outflow has an hourglass shape where the cavities are not seen. We interpret the shapes that the gas traces as cavities excavated by an ancient outflow. We report a detection of line emission from the circumstellar disc and derive a lower limit of the gas mass of 3 MJup.
The Hot Horizontal-Branch Stars in omega Centauri
NASA Technical Reports Server (NTRS)
Moehler, S.; Dreizler, S.; Lanz, T.; Bono, G.; Sweigart, A. V.; Calamida, A.; Nonino, M.
2010-01-01
Context. UV observations of some massive globular clusters have revealed a significant population of stars hotter and fainter than the hot end of the horizontal branch (HB), the so-called blue hook stars. This feature might be explained either by the late hot flasher scenario where stars experience the helium flash while on the white dwarf cooling curve or by the progeny of the helium-enriched sub-population recently postulated to exist in some clusters. Previous spectroscopic analyses of blue hook stars in co Cen and NGC 2808 support the late hot flasher scenario, but the stars contain much less helium than expected and the predicted C, N enrichment could not be verified. Aims. We compare observed effective temperatures, surface gravities, helium abundances, and carbon line strengths (where detectable) of our targets stars to the predictions of the two scenarios. Methods. Moderately high resolution spectra of hot HB stars in the globular cluster omega-Cen were analysed for radial velocity variations, atmospheric parameters and abundances using LTE and non-LTE model atmospheres. Results. We find no evidence for close binaries among our target stars. All stars below 30 000 K are helium-poor and very similar to HB stars observed in that temperature range in other globular clusters. In the temperature range 30000 K to 50000 K we find that 28% of our stars are helium-poor (log ((sup n)He/(sup n )H)< - 1.6), while 72% have roughly solar or super-solar helium abundance (log ((sup n)He/(sup n )H) >/= -1.5). We also find carbon enrichment strongly correlated with helium enrichment, with a maximum carbon enrichment of 3% by mass. Conclusions. The strong carbon enrichment in tandem with helium enrichment is predicted by the late hot flasher scenario, but not by the helium-enrichment scenario. We conclude that the helium-rich HB stars in omega-Cen cannot be explained solely by the helium-enrichment scenario invoked to explain the blue main sequence.
The center of the core-cusp globular cluster M15: CFHT and HST Observations, ALLFRAME reductions
NASA Astrophysics Data System (ADS)
Stetson, Peter B.
1994-03-01
The central brightness cusps seen in some globular clusters are thought to be the relics of a gravothermal core collapse that occurred sometime in the clusters' past. Recent observations show that the centers of such clusters are bluer than their outskirts, indicating that the stellar populations there are somehow different than those farther out, presumably as a result of unusual physical processes that took place in these extremely dense regions. Here I analyze a large body of digital imagery from the Canada-France-Hawaii Telescope and the Hubble Space Telescope to obtain color-magnitude and color-color diagrams for stars in the central two arcminutes of the prototypical core-cusp globular cluster M15 = NGC 7078 = C 2127 + 119. These data were reduced with a new computer program, named ALLFRAME, that is described in detail here for the first time. ALLFRAME makes simultaneous use of the geometric and photometric information from all images of a given field to derive a self-consistent set of positions and magnitudes for all detected starlike objects in that area of sky, thereby extending the range of magnitude and crowding conditions for which useful photometry is obtainable. I tentatively conclude that the color gradient in M15 is due to three distinct effects: (1) there is a deficiency of the brightest red giants in the central regions of the cluster; (2) the giant branch of the dominant cluster population shifts systematically toward the blue as the center of the cluster is approached; and (3) the very center of the cluster (radius approximately equal or less than 12 seconds) contains a large population of blue and yellow stragglers that occupy the area of the color-magnitude diagram between the main-sequence turnoff and the horizontal branch and between the extended blue horizontal branch and the subgiant branch; many of these appear to have a significant ultraviolet excess.
Kingston, S E; Martino, P; Melendy, M; Reed, F A; Carlon, D B
2018-03-01
A key component to understanding the evolutionary response to a changing climate is linking underlying genetic variation to phenotypic variation in stress response. Here, we use a genome-wide association approach (GWAS) to understand the genetic architecture of calcification rates under simulated climate stress. We take advantage of the genomic gradient across the blue mussel hybrid zone (Mytilus edulis and Mytilus trossulus) in the Gulf of Maine (GOM) to link genetic variation with variance in calcification rates in response to simulated climate change. Falling calcium carbonate saturation states are predicted to negatively impact many marine organisms that build calcium carbonate shells - like blue mussels. We sampled wild mussels and measured net calcification phenotypes after exposing mussels to a 'climate change' common garden, where we raised temperature by 3°C, decreased pH by 0.2 units and limited food supply by filtering out planktonic particles >5 μm, compared to ambient GOM conditions in the summer. This climate change exposure greatly increased phenotypic variation in net calcification rates compared to ambient conditions. We then used regression models to link the phenotypic variation with over 170 000 single nucleotide polymorphism loci (SNPs) generated by genotype by sequencing to identify genomic locations associated with calcification phenotype, and estimate heritability and architecture of the trait. We identified at least one of potentially 2-10 genomic regions responsible for 30% of the phenotypic variation in calcification rates that are potential targets of natural selection by climate change. Our simulations suggest a power of 13.7% with our study's average effective sample size of 118 individuals and rare alleles, but a power of >90% when effective sample size is 900. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.
Jørgensen, Marie Birk; Korshøj, Mette; Lagersted-Olsen, Julie; Villumsen, Morten; Mortensen, Ole Steen; Skotte, Jørgen; Søgaard, Karen; Madeleine, Pascal; Thomsen, Birthe Lykke; Holtermann, Andreas
2013-07-20
Among blue-collar workers, high physical work demands are generally considered to be the main cause of musculoskeletal pain and work disability. However, current available research on this topic has been criticised for using self-reported data, cross-sectional design, insufficient adjustment for potential confounders, and inadequate follow-up on the recurrent and fluctuating pattern of musculoskeletal pain. Recent technological advances have provided possibilities for objective diurnal field measurements of physical activities and frequent follow-up on musculoskeletal pain.The main aim of this paper is to describe the background, design, methods, limitations and perspectives of the Danish Physical Activity cohort with Objective measurements (DPhacto) investigating the association between objectively measured physical activities capturing work and leisure time and frequent measurements of musculoskeletal pain among blue-collar workers. Approximately 2000 blue-collar workers are invited for the study and asked to respond to a baseline questionnaire, participate in physical tests (i.e. muscle strength, aerobic fitness, back muscle endurance and flexibility), to wear accelerometers and a heart rate monitor for four consecutive days, and finally respond to monthly text messages regarding musculoskeletal pain and quarterly questionnaires regarding the consequences of musculoskeletal pain on work activities, social activities and work ability for a one-year follow-up period. This study will provide novel information on the association between physical activities at work and musculoskeletal pain. The study will provide valid and precise documentation about the relation between physical work activities and musculoskeletal pain and its consequences among blue-collar workers.
2013-01-01
Background Among blue-collar workers, high physical work demands are generally considered to be the main cause of musculoskeletal pain and work disability. However, current available research on this topic has been criticised for using self-reported data, cross-sectional design, insufficient adjustment for potential confounders, and inadequate follow-up on the recurrent and fluctuating pattern of musculoskeletal pain. Recent technological advances have provided possibilities for objective diurnal field measurements of physical activities and frequent follow-up on musculoskeletal pain. The main aim of this paper is to describe the background, design, methods, limitations and perspectives of the Danish Physical Activity cohort with Objective measurements (DPhacto) investigating the association between objectively measured physical activities capturing work and leisure time and frequent measurements of musculoskeletal pain among blue-collar workers. Methods/design Approximately 2000 blue-collar workers are invited for the study and asked to respond to a baseline questionnaire, participate in physical tests (i.e. muscle strength, aerobic fitness, back muscle endurance and flexibility), to wear accelerometers and a heart rate monitor for four consecutive days, and finally respond to monthly text messages regarding musculoskeletal pain and quarterly questionnaires regarding the consequences of musculoskeletal pain on work activities, social activities and work ability for a one-year follow-up period. Discussion This study will provide novel information on the association between physical activities at work and musculoskeletal pain. The study will provide valid and precise documentation about the relation between physical work activities and musculoskeletal pain and its consequences among blue-collar workers. PMID:23870666
A proteomic analysis of leaf sheaths from rice.
Shen, Shihua; Matsubae, Masami; Takao, Toshifumi; Tanaka, Naoki; Komatsu, Setsuko
2002-10-01
The proteins extracted from the leaf sheaths of rice seedlings were separated by 2-D PAGE, and analyzed by Edman sequencing and mass spectrometry, followed by database searching. Image analysis revealed 352 protein spots on 2-D PAGE after staining with Coomassie Brilliant Blue. The amino acid sequences of 44 of 84 proteins were determined; for 31 of these proteins, a clear function could be assigned, whereas for 12 proteins, no function could be assigned. Forty proteins did not yield amino acid sequence information, because they were N-terminally blocked, or the obtained sequences were too short and/or did not give unambiguous results. Fifty-nine proteins were analyzed by mass spectrometry; all of these proteins were identified by matching to the protein database. The amino acid sequences of 19 of 27 proteins analyzed by mass spectrometry were similar to the results of Edman sequencing. These results suggest that 2-D PAGE combined with Edman sequencing and mass spectrometry analysis can be effectively used to identify plant proteins.
McTaggart, Lisa; Richardson, Susan E.; Seah, Christine; Hoang, Linda; Fothergill, Annette; Zhang, Sean X.
2011-01-01
Rapid identification of Cryptococcus neoformans var. grubii, Cryptococcus neoformans var. neoformans, and Cryptococcus gattii is imperative for facilitation of prompt treatment of cryptococcosis and for understanding the epidemiology of the disease. Our purpose was to evaluate a test algorithm incorporating commercial rapid biochemical tests, differential media, and DNA sequence analysis that will allow us to differentiate these taxa rapidly and accurately. We assessed 147 type, reference, and clinical isolates, including 6 other Cryptococcus spp. (10 isolates) and 14 other yeast species (24 isolates), using a 4-hour urea broth test (Remel), a 24-hour urea broth test (Becton Dickinson), a 4-hour caffeic acid disk test (Hardy Diagnostics and Remel), 40- to 44-hour growth assessment on l-canavanine glycine bromothymol blue (CGB) agar, and intergenic spacer (IGS) sequence analysis. All 123 Cryptococcus isolates hydrolyzed urea, along with 7 isolates of Rhodotorula and Trichosporon. Eighty-five of 86 C. neoformans (99%) and 26 of 27 C. gattii (96%) isolates had positive caffeic acid results, unlike the other cryptococci (0/10) and yeast species (0/24). Together, these two tests positively identified virtually all C. neoformans/C. gattii isolates (98%) within 4 h. CGB agar or IGS sequencing further differentiated these isolates within 48 h. On CGB, 25 of 27 (93%) C. gattii strains induced a blue color change, in contrast to 0 of 86 C. neoformans isolates. Neighbor-joining cluster analysis of IGS sequences differentiated C. neoformans var. grubii, C. neoformans var. neoformans, and C. gattii. Based on these results, we describe a rapid identification algorithm for use in a microbiology laboratory to distinguish clinically relevant Cryptococcus spp. PMID:21593254
McTaggart, Lisa; Richardson, Susan E; Seah, Christine; Hoang, Linda; Fothergill, Annette; Zhang, Sean X
2011-07-01
Rapid identification of Cryptococcus neoformans var. grubii, Cryptococcus neoformans var. neoformans, and Cryptococcus gattii is imperative for facilitation of prompt treatment of cryptococcosis and for understanding the epidemiology of the disease. Our purpose was to evaluate a test algorithm incorporating commercial rapid biochemical tests, differential media, and DNA sequence analysis that will allow us to differentiate these taxa rapidly and accurately. We assessed 147 type, reference, and clinical isolates, including 6 other Cryptococcus spp. (10 isolates) and 14 other yeast species (24 isolates), using a 4-hour urea broth test (Remel), a 24-hour urea broth test (Becton Dickinson), a 4-hour caffeic acid disk test (Hardy Diagnostics and Remel), 40- to 44-hour growth assessment on l-canavanine glycine bromothymol blue (CGB) agar, and intergenic spacer (IGS) sequence analysis. All 123 Cryptococcus isolates hydrolyzed urea, along with 7 isolates of Rhodotorula and Trichosporon. Eighty-five of 86 C. neoformans (99%) and 26 of 27 C. gattii (96%) isolates had positive caffeic acid results, unlike the other cryptococci (0/10) and yeast species (0/24). Together, these two tests positively identified virtually all C. neoformans/C. gattii isolates (98%) within 4 h. CGB agar or IGS sequencing further differentiated these isolates within 48 h. On CGB, 25 of 27 (93%) C. gattii strains induced a blue color change, in contrast to 0 of 86 C. neoformans isolates. Neighbor-joining cluster analysis of IGS sequences differentiated C. neoformans var. grubii, C. neoformans var. neoformans, and C. gattii. Based on these results, we describe a rapid identification algorithm for use in a microbiology laboratory to distinguish clinically relevant Cryptococcus spp.
Zhu, Longjiao; Shao, Xiangli; Luo, Yunbo; Huang, Kunlung; Xu, Wentao
2017-05-19
A two-way colorimetric biosensor based on unmodified gold nanoparticles (GNPs) and a switchable double-stranded DNA (dsDNA) concatemer have been demonstrated. Two hairpin probes (H1 and H2) were first designed that provided the fuels to assemble the dsDNA concatemers via hybridization chain reaction (HCR). A functional hairpin (FH) was rationally designed to recognize the target sequences. All the hairpins contained a single-stranded DNA (ssDNA) loop and sticky end to prevent GNPs from salt-induced aggregation. In the presence of target sequence, the capture probe blocked in the FH recognizes the target to form a duplex DNA, which causes the release of the initiator probe by FH conformational change. This process then starts the alternate-opening of H1 and H2 through HCR, and dsDNA concatemers grow from the target sequence. As a result, unmodified GNPs undergo salt-induced aggregation because the formed dsDNA concatemers are stiffer and provide less stabilization. A light purple-to-blue color variation was observed in the bulk solution, termed the light-off sensing way. Furthermore, H1 ingeniously inserted an aptamer sequence to generate dsDNA concatemers with multiple small molecule binding sites. In the presence of small molecule targets, concatemers can be disassembled into mixtures with ssDNA sticky ends. A blue-to-purple reverse color variation was observed due to the regeneration of the ssDNA, termed the light-on way. The two-way biosensor can detect both nucleic acids and small molecule targets with one sensing device. This switchable sensing element is label-free, enzyme-free, and sophisticated-instrumentation-free. The detection limits of both targets were below nanomolar.
Krupke, William F.; Payne, Stephen A.; Marshall, Christopher D.
2001-01-01
The invention provides an efficient, compact means of generating blue laser light at a wavelength near .about.493+/-3 nm, based on the use of a laser diode-pumped Yb-doped laser crystal emitting on its zero phonon line (ZPL) resonance transition at a wavelength near .about.986+/-6 nm, whose fundamental infrared output radiation is harmonically doubled into the blue spectral region. The invention is applied to the excitation of biofluorescent dyes (in the .about.490-496 nm spectral region) utilized in flow cytometry, immunoassay, DNA sequencing, and other biofluorescence instruments. The preferred host crystals have strong ZPL fluorecence (laser) transitions lying in the spectral range from .about.980 to .about.992 nm (so that when frequency-doubled, they produce output radiation in the spectral range from 490 to 496 nm). Alternate preferred Yb doped tungstate crystals, such as Yb:KY(WO.sub.4).sub.2, may be configured to lase on the resonant ZPL transition near 981 nm (in lieu of the normal 1025 nm transition). The laser light is then doubled in the blue at 490.5 nm.
Analysis and Simulation of a Blue Energy Cycle
Sharma, Ms. Ketki; Kim, Yong-Ha; Yiacoumi, Sotira; ...
2016-01-30
The mixing process of fresh water and seawater releases a significant amount of energy and is a potential source of renewable energy. The so called ‘blue energy’ or salinity-gradient energy can be harvested by a device consisting of carbon electrodes immersed in an electrolyte solution, based on the principle of capacitive double layer expansion (CDLE). In this study, we have investigated the feasibility of energy production based on the CDLE principle. Experiments and computer simulations were used to study the process. Mesoporous carbon materials, synthesized at the Oak Ridge National Laboratory, were used as electrode materials in the experiments. Neutronmore » imaging of the blue energy cycle was conducted with cylindrical mesoporous carbon electrodes and 0.5 M lithium chloride as the electrolyte solution. For experiments conducted at 0.6 V and 0.9 V applied potential, a voltage increase of 0.061 V and 0.054 V was observed, respectively. From sequences of neutron images obtained for each step of the blue energy cycle, information on the direction and magnitude of lithium ion transport was obtained. A computer code was developed to simulate the process. Experimental data and computer simulations allowed us to predict energy production.« less
Sandoval-Castillo, Jonathan; Jenner, K. Curt S.; Gill, Peter C.; Jenner, Micheline-Nicole M.; Morrice, Margaret G.
2018-01-01
Genetic datasets of tens of markers have been superseded through next-generation sequencing technology with genome-wide datasets of thousands of markers. Genomic datasets improve our power to detect low population structure and identify adaptive divergence. The increased population-level knowledge can inform the conservation management of endangered species, such as the blue whale (Balaenoptera musculus). In Australia, there are two known feeding aggregations of the pygmy blue whale (B. m. brevicauda) which have shown no evidence of genetic structure based on a small dataset of 10 microsatellites and mtDNA. Here, we develop and implement a high-resolution dataset of 8294 genome-wide filtered single nucleotide polymorphisms, the first of its kind for blue whales. We use these data to assess whether the Australian feeding aggregations constitute one population and to test for the first time whether there is adaptive divergence between the feeding aggregations. We found no evidence of neutral population structure and negligible evidence of adaptive divergence. We propose that individuals likely travel widely between feeding areas and to breeding areas, which would require them to be adapted to a wide range of environmental conditions. This has important implications for their conservation as this blue whale population is likely vulnerable to a range of anthropogenic threats both off Australia and elsewhere. PMID:29410806
Wellehan, James F. X.; Johnson, April J.; Harrach, Balázs; Benkö, Mária; Pessier, Allan P.; Johnson, Calvin M.; Garner, Michael M.; Childress, April; Jacobson, Elliott R.
2004-01-01
A consensus nested-PCR method was designed for investigation of the DNA polymerase gene of adenoviruses. Gene fragments were amplified and sequenced from six novel adenoviruses from seven lizard species, including four species from which adenoviruses had not previously been reported. Host species included Gila monster, leopard gecko, fat-tail gecko, blue-tongued skink, Tokay gecko, bearded dragon, and mountain chameleon. This is the first sequence information from lizard adenoviruses. Phylogenetic analysis indicated that these viruses belong to the genus Atadenovirus, supporting the reptilian origin of atadenoviruses. This PCR method may be useful for obtaining templates for initial sequencing of novel adenoviruses. PMID:15542689
Wellehan, James F X; Johnson, April J; Harrach, Balázs; Benkö, Mária; Pessier, Allan P; Johnson, Calvin M; Garner, Michael M; Childress, April; Jacobson, Elliott R
2004-12-01
A consensus nested-PCR method was designed for investigation of the DNA polymerase gene of adenoviruses. Gene fragments were amplified and sequenced from six novel adenoviruses from seven lizard species, including four species from which adenoviruses had not previously been reported. Host species included Gila monster, leopard gecko, fat-tail gecko, blue-tongued skink, Tokay gecko, bearded dragon, and mountain chameleon. This is the first sequence information from lizard adenoviruses. Phylogenetic analysis indicated that these viruses belong to the genus Atadenovirus, supporting the reptilian origin of atadenoviruses. This PCR method may be useful for obtaining templates for initial sequencing of novel adenoviruses.
Koelsche, Christian; Hartmann, Wolfgang; Schrimpf, Daniel; Stichel, Damian; Jabar, Susanne; Ranft, Andreas; Reuss, David E; Sahm, Felix; Jones, David T W; Bewerunge-Hudler, Melanie; Trautmann, Marcel; Klingebiel, Thomas; Vokuhl, Christian; Gessler, Manfred; Wardelmann, Eva; Petersen, Iver; Baumhoer, Daniel; Flucke, Uta; Antonescu, Cristina; Esteller, Manel; Fröhling, Stefan; Kool, Marcel; Pfister, Stefan M; Mechtersheimer, Gunhild; Dirksen, Uta; von Deimling, Andreas
2018-03-23
Undifferentiated solid tumors with small blue round cell histology and expression of CD99 mostly resemble Ewing sarcoma. However, they also may include other tumors such as mesenchymal chondrosarcoma, synovial sarcoma, or small cell osteosarcoma. Definitive classification usually requires detection of entity-specific mutations. While this approach identifies the majority of Ewing sarcomas, a subset of lesions remains unclassified and, therefore, has been termed "Ewing-like sarcomas" or small blue round cell tumors not otherwise specified. We developed an approach for further characterization of small blue round cell tumors not otherwise specified using an array-based DNA-methylation profiling approach. Data were analyzed by unsupervised clustering and t-distributed stochastic neighbor embedding analysis and compared with a reference methylation data set of 460 well-characterized prototypical sarcomas encompassing 18 subtypes. Verification was performed by additional FISH analyses, RNA sequencing from formalin-fixed paraffin-embedded material or immunohistochemical marker analyses. In a cohort of more than 1,000 tumors assumed to represent Ewing sarcomas, 30 failed to exhibit the typical EWS translocation. These tumors were subjected to methylation profiling and could be assigned to Ewing sarcoma in 14 (47%), to small blue round cell tumors with CIC alteration in 6 (20%), to small blue round cell tumors with BCOR alteration in 4 (13%), to synovial sarcoma and to malignant rhabdoid tumor in 2 cases each. One single case each was allotted to mesenchymal chondrosarcoma and adamantinoma. 12/14 tumors classified as Ewing sarcoma could be verified by demonstrating either a canonical EWS translocation evading initial testing, by identifying rare breakpoints or fusion partners. The methylation-based assignment of the remaining small blue round cell tumors not otherwise specified also could be verified by entity-specific molecular alterations in 13/16 cases. In conclusion, array-based DNA-methylation analysis of undifferentiated tumors with small blue round cell histology is a powerful tool for precisely classifying this diagnostically challenging tumor group.
NASA Technical Reports Server (NTRS)
Guhathakurta, Puragra; Yanny, Brian; Schneider, Donald P.; Bahcall, John N.
1992-01-01
Accurate photometry for individual post-main-sequence stars in the core of the Galactic globular cluster 47 Tuc is presented and analyzed using an empirical point spread function model and Monte Carlo simulations. A V vs. V-I color-magnitude diagrams is constructed which shows several distinct stellar types, including RGB and HB stars. Twenty-four blue straggler stars are detected in 47 Tuc, more concentrated toward the center of the cluster than the giants. This supports the hypothesis is that the stragglers are either coalesced stars or members of binary systems that are more massive than single stars. The radial profile of the projected stellar density is flat in the central region of 47 Tuc with a core radius of 23 +/- 2 arcsec. No signature of a collapsed core is evident. The observed radial cumulative distribution of stars rules out the presence of a massive compact object in the center.
NASA Astrophysics Data System (ADS)
Zouhri, L.
2001-05-01
The Mamora aquifer, in the northern Moroccan Meseta, constitutes the main regional water resource. Its impermeable basement is mostly composed of blue marls. The lithostratigraphy of the basin aquifer is characterised by a sequence of sandstones, sandy limestones, conglomerates and sandy clays. The structure of the basement of the Mamora aquifer, deduced from electrical resistivity measurements, allowed the hydrogeological behaviour of the reservoir, and the direction of the groundwater flow, to be established. The combination of the lithological, morphological, piezometric, geophysical and structural investigations revealed a northward thickening of the substrate with groundwater flow towards the Rharb (to the north) and towards the Atlantic Ocean (northwest). This 'multicriteria' approach enabled a structural model to be defined, which correlated well with the aquifer geometry and the groundwater flow. The variability of the hydrogeological units, and the northward thickening of the sedimentary facies, were controlled by northeast-southwest orientated faults, which affect their impermeability.
Evolution of close binary systems: Observational aspects
NASA Technical Reports Server (NTRS)
Plavec, M. J.
1981-01-01
Detached close binary systems define the main sequence band satisfactorily, but very little is known about the masses of giants and supergiants. High dispersion international ultraviolet explorer satellite observations promise an improvement, since blue companions are now frequently found to late type supergiants. Mu Sagittaril and in particular Xi Aurigae are discussed in more detail. The barium star abundance anomaly appears to be due to mass transfer in interacting systems. The symbiotic stars are another type of binary systems containing late type giants; several possible models for the hotter star and for the type of interaction are discussed. The W Serpentis stars appear to be Algols in the rapid phase of mass transfer, but a possible link relating them to the symbiotics is also indicated. Evidence of hot circumstellar plasmas has now been found in several ordinary Algols; there may exist a smooth transition between very quiescent Algols and the W Serpentis stars. Beta Lyrae is discussed in the light of new spectrophotometric results.
A spectrum of the veiled T Tauri star CY Tau
NASA Technical Reports Server (NTRS)
Stuewe, J. A.; Schultz, R.
1994-01-01
We present a flux calibrated spectrum of the star listed as CY Tau in the `General Catalog of Variable Stars 4th ed.' in the spectral range 3700 A less than or equal to lambda less than or equal to 6400 A with a resolution of approximately equals 15 A showing the Balmer-Series from H(sub beta) to H(sub 10) as well as the CaII H (in blend with H(sub epsilon) and K lines in emission. Apart from the emission lines the spectrum is composed of a continuum equivalent to that of an ordinary pre-main sequence star (i.e. a `naked' T Tau) of spectral type M2 V with emission lines plus a `blue' veiling continuum that can be described as black body radiation of temperature T(sub BL) approximately equals 7000K due to accretion onto a boundary layer at a rate of M-dot(sub acc) greater than or approximately = 2.18 10(exp -8) solar mass/a.
Analysis of the evolved contact system V367 Cygni
NASA Astrophysics Data System (ADS)
Li, Yan-Feng; Leung, Kam-Ching
1987-02-01
Three groups of observations of V367 Cyg - Fresa's blue light curve (1957-1960, group I), Heiser's UBV light curves (1960-1961, group II), and BV light curves of Kalv and Pustylnik (1967-1973, group III) - were analyzed separately with the Wilson and Devinney approach. An appropriate value of the mass ratio of the system was derived from a q-search procedure. Three contact solutions were obtained with over-contact of 0.0 percent (critical contact), 4.5 percent, and 8.8 percent, corresponding to the observations of group I, group II, and group III respectively; and no third lights were found in the light curves. Absolute dimensions of the system were calculated with the photometric mass ratio. The observed radii are found to be about a factor of six greater than the zero-age main-sequence values for stars of corresponding masses. It is suggested that V367 Cyg is at an evolved contact phase with active mass transfer or mass loss or both.
RW Sextantis, a disk with a hot, high-velocity wind
NASA Astrophysics Data System (ADS)
Greenstein, J. L.; Oke, J. B.
1982-07-01
The continuum spectrum of the flickering blue variable RW Sex was observed from 10,000 to 1150 A. The star is a cataclysmic variable currently stabilized at maximum, and the spectrum is dominated by an accretion disk, with flat spectrum in the ultraviolet, except at more than 5000 A, where a blackbody near 7000 K is seen. A distance of 400 pc is derived, if the latter arises from an F type main sequence star. The accretion rate required is near 10 to the -8th solar masses per year. Only weak emission is seen, except for Lyman alpha; strong, broad UV absorption lines are seen with centers displaced up to -3000 km/s, with terminal velocities up to -4500 km/s, the velocity of escape from a white dwarf. The low X-ray flux may arise from absorption within an unusually dense, hot wind from the innermost portions of the disk. The estimated mass loss rate is nearly 10 to the -12th solar masses per year.
RW Sextantis, a disk with a hot, high-velocity wind
NASA Technical Reports Server (NTRS)
Greenstein, J. L.; Oke, J. B.
1982-01-01
The continuum spectrum of the flickering blue variable RW Sex was observed from 10,000 to 1150 A. The star is a cataclysmic variable currently stabilized at maximum, and the spectrum is dominated by an accretion disk, with flat spectrum in the ultraviolet, except at more than 5000 A, where a blackbody near 7000 K is seen. A distance of 400 pc is derived, if the latter arises from an F type main sequence star. The accretion rate required is near 10 to the -8th solar masses per year. Only weak emission is seen, except for Lyman alpha; strong, broad UV absorption lines are seen with centers displaced up to -3000 km/s, with terminal velocities up to -4500 km/s, the velocity of escape from a white dwarf. The low X-ray flux may arise from absorption within an unusually dense, hot wind from the innermost portions of the disk. The estimated mass loss rate is nearly 10 to the -12th solar masses per year.
Dal-Forno, Manuela; Lücking, Robert; Bungartz, Frank; Yánez-Ayabaca, Alba; Marcelli, Marcelo P; Spielmann, Adriano A; Coca, Luis Fernando; Chaves, José Luis; Aptroot, Andre; Sipman, Harrie J M; Sikaroodi, Masoumeh; Gillevet, Patrick; Lawrey, James D
2016-01-01
We present a taxonomic revision of the lichenized basidiomycete genus Acantholichen, species of which produce a characteristic blue-gray, microsquamulose thallus with spiny apical hyphal cells known as acanthohyphidia. Since its discovery, the genus was thought to be monospecific, only including the generic type, A. pannarioides. However, a detailed morphological and anatomical study of recently collected specimens from the Galápagos, Costa Rica, Brazil and Colombia, combined with a molecular phylogenetic analysis of the internal transcribed spacer (ITS1-5.8S-ITS2) region and 28S of the nuc rDNA and RPB2 sequences, revealed a much more diverse and widespread species assemblage. Based on the results of these analyses, we describe five new species in the genus: A. albomarginatus, A. campestris, A. galapagoensis, A. sorediatus and A. variabilis. We also provide an identification key to all species, anatomical and morphological descriptions, photographs and a table comparing main characters of each species. © 2016 by The Mycological Society of America.
TYC 3159-6-1: a runaway blue supergiant
NASA Astrophysics Data System (ADS)
Gvaramadze, V. V.; Miroshnichenko, A. S.; Castro, N.; Langer, N.; Zharikov, S. V.
2014-01-01
We report the results of optical spectroscopy of a candidate evolved massive star in the Cygnus-X region, TYC 3159-6-1, revealed via detection of its curious circumstellar nebula in archival data of the Spitzer Space Telescope. We classify TYC 3159-6-1 as an O9.5-O9.7 Ib star and derive its fundamental parameters by using the stellar atmosphere code FASTWIND. The He and CNO abundances in the photosphere of TYC 3159-6-1 are consistent with the solar abundances, suggesting that the star only recently evolved off the main sequence. Proper motion and radial velocity measurements for TYC 3159-6-1 show that it is a runaway star. We propose that Dolidze 7 is its parent cluster. We discuss the origin of the nebula around TYC 3159-6-1 and suggest that it might be produced in several successive episodes of enhanced mass-loss rate (outbursts) caused by rotation of the star near the critical Ω limit.
Two opsins from the compound eye of the crab Hemigrapsus sanguineus
Sakamoto; Hisatomi; Tokunaga; Eguchi
1996-01-01
The primary structures of two opsins from the brachyuran crab Hemigrapsus sanguineus were deduced from the cDNA nucleotide sequences. Both deduced proteins were composed of 377 amino acid residues and included residues highly conserved in visual pigments of other species, and the proteins were 75 % identical to each other. The distribution of opsin transcripts in the compound eye, determined by in situ hybridization, suggested that the mRNAs of the two opsins were expressed simultaneously in all of the seven retinular cells (R1-R7) forming the main rhabdom in each ommatidium. Two different visual pigments may be present in one photoreceptor cell in this brachyuran crab. The spectral sensitivity of the compound eye was also determined by recording the electroretinogram. The compound eye was maximally sensitive at about 480 nm. These and previous findings suggest that both opsins of this brachyuran crab produce visual pigments with maximal absorption in the blue-green region of the spectrum. Evidence is presented that crustaceans possess multiple pigment systems for vision.
Ding, Fei; Xie, Yong; Peng, Wei; Peng, Yu-Kui
2016-05-01
Methylene blue is a phenothiazine agent, that possesses a diversity of biomedical and biological therapeutic purpose, and it has also become the lead compound for the exploitation of other pharmaceuticals such as chlorpromazine and the tricyclic antidepressants. However, the U.S. Food and Drug Administration has acquired cases of detrimental effects of methylene blue toxicities such as hemolytic anemia, methemoglobinemia and phototoxicity. In this work, the molecular recognition of methylene blue by two globular proteins, hemoglobin and lysozyme was characterized by employing fluorescence, circular dichroism (CD) along with molecular modeling at the molecular scale. The recognition of methylene blue with proteins appears fluorescence quenching via static type, this phenomenon does cohere with time-resolved fluorescence lifetime decay that nonfluorescent protein-drug conjugate formation has a strength of 10(4)M(-1), and the primary noncovalent bonds, that is hydrogen bonds, π-conjugated effects and hydrophobic interactions were operated and remained adduct stable. Meantime, the results of far-UV CD and synchronous fluorescence suggest that the α-helix of hemoglobin/lysozyme decreases from 78.2%/34.7% (free) to 58.7%/23.8% (complex), this elucidation agrees well with the elaborate description of three-dimensional fluorescence showing the polypeptide chain of proteins partially destabilized upon conjugation with methylene blue. Furthermore, both extrinsic fluorescent indicator and molecular modeling clearly exhibit methylene blue is situated within the cavity constituted by α1, β2 and α2 subunits of hemoglobin, while it was located at the deep fissure on the lysozyme surface and Trp-62 and Trp-63 residues are nearby. With the aid of computational analyses and combining the wet experiments, it can evidently be found that the recognition ability of proteins for methylene blue is patterned upon the following sequence: lysozyme
Galaxy And Mass Assembly (GAMA): deconstructing bimodality - I. Red ones and blue ones
NASA Astrophysics Data System (ADS)
Taylor, Edward N.; Hopkins, Andrew M.; Baldry, Ivan K.; Bland-Hawthorn, Joss; Brown, Michael J. I.; Colless, Matthew; Driver, Simon; Norberg, Peder; Robotham, Aaron S. G.; Alpaslan, Mehmet; Brough, Sarah; Cluver, Michelle E.; Gunawardhana, Madusha; Kelvin, Lee S.; Liske, Jochen; Conselice, Christopher J.; Croom, Scott; Foster, Caroline; Jarrett, Thomas H.; Lara-Lopez, Maritza; Loveday, Jon
2015-01-01
We measure the mass functions for generically red and blue galaxies, using a z < 0.12 sample of log M* > 8.7 field galaxies from the Galaxy And Mass Assembly (GAMA) survey. Our motivation is that, as we show, the dominant uncertainty in existing measurements stems from how `red' and `blue' galaxies have been selected/defined. Accordingly, we model our data as two naturally overlapping populations, each with their own mass function and colour-mass relation, which enables us characterize the two populations without having to specify a priori which galaxies are `red' and `blue'. Our results then provide the means to derive objective operational definitions for the terms `red' and `blue', which are based on the phenomenology of the colour-mass diagrams. Informed by this descriptive modelling, we show that (1) after accounting for dust, the stellar colours of `blue' galaxies do not depend strongly on mass; (2) the tight, flat `dead sequence' does not extend much below log M* ˜ 10.5; instead, (3) the stellar colours of `red' galaxies vary rather strongly with mass, such that lower mass `red' galaxies have bluer stellar populations; (4) below log M* ˜ 9.3, the `red' population dissolves into obscurity, and it becomes problematic to talk about two distinct populations; as a consequence, (5) it is hard to meaningfully constrain the shape, including the existence of an upturn, of the `red' galaxy mass function below log M* ˜ 9.3. Points 1-4 provide meaningful targets for models of galaxy formation and evolution to aim for.
conditions. stage graphic: vertical blue rule Main stage: See through car with battery, engine, generator , power split device, and electric motor visible. The car is stopped at an intersection. Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is
USDA-ARS?s Scientific Manuscript database
An indirect capture model assay using colloidal Au nanoparticles is demonstrated for surface enhanced Raman scattering (SERS) spectroscopy detection of DNA. The sequence targeted for capture is derived from the West Nile Virus (WNV) RNA genome and was selected on the basis of exhibiting minimal seco...
Genotyping-by-sequencing of waxy and glossy near-isogenic broccoli lines
USDA-ARS?s Scientific Manuscript database
Wild-type Brassica oleracea L. have matte blue-green leaves caused by an interaction between leaf pigmentation and a waxy bloom coating the surface. Glossy mutants have reduced and/or altered epicuticular wax giving the leaves a shiny green appearance and have been identified in most B. oleracea cro...
33 CFR 165.T01-0470 - Safety Zones; Maine Events in Captain of the Port Long Island Sound Zone.
Code of Federal Regulations, 2011 CFR
2011-07-01
... vessel or the designated representative, by siren, radio, flashing light or other means, the operator of...:30 p.m. • Location: Water of the Great South Bay, Blue Point, NY in approximate position 40°44′06.28... South Bay, Blue Point, NY in approximate position, 40°44′06.28″ N, 073°01′02.50″ W (NAD 83). 7.15Montauk...
Martian soil stratigraphy and rock coatings observed in color-enhanced Viking Lander images
NASA Technical Reports Server (NTRS)
Strickland, E. L., III
1979-01-01
Subtle color variations of martian surface materials were enhanced in eight Viking Lander (VL) color images. Well-defined soil units recognized at each site (six at VL-1 and four at VL-2), are identified on the basis of color, texture, morphology, and contact relations. The soil units at the Viking 2 site form a well-defined stratigraphic sequence, whereas the sequence at the Viking 1 site is only partially defined. The same relative soil colors occur at the two sites, suggesting that similar soil units are widespread on Mars. Several types of rock surface materials can be recognized at the two sites; dark, relatively 'blue' rock surfaces are probably minimally weathered igneous rock, whereas bright rock surfaces, with a green/(blue + red) ratio higher than that of any other surface material, are interpreted as a weathering product formed in situ on the rock. These rock surface types are common at both sites. Soil adhering to rocks is common at VL-2, but rare at VL-1. The mechanism that produces the weathering coating on rocks probably operates planet-wide.
Systemic AA amyloidosis in the red fox (Vulpes vulpes).
Rising, Anna; Cederlund, Ella; Palmberg, Carina; Uhlhorn, Henrik; Gaunitz, Stefan; Nordling, Kerstin; Ågren, Erik; Ihse, Elisabet; Westermark, Gunilla T; Tjernberg, Lars; Jörnvall, Hans; Johansson, Jan; Westermark, Per
2017-11-01
Amyloid A (AA) amyloidosis occurs spontaneously in many mammals and birds, but the prevalence varies considerably among different species, and even among subgroups of the same species. The Blue fox and the Gray fox seem to be resistant to the development of AA amyloidosis, while Island foxes have a high prevalence of the disease. Herein, we report on the identification of AA amyloidosis in the Red fox (Vulpes vulpes). Edman degradation and tandem MS analysis of proteolyzed amyloid protein revealed that the amyloid partly was composed of full-length SAA. Its amino acid sequence was determined and found to consist of 111 amino acid residues. Based on inter-species sequence comparisons we found four residue exchanges (Ser31, Lys63, Leu71, Lys72) between the Red and Blue fox SAAs. Lys63 seems unique to the Red fox SAA. We found no obvious explanation to how these exchanges might correlate with the reported differences in SAA amyloidogenicity. Furthermore, in contrast to fibrils from many other mammalian species, the isolated amyloid fibrils from Red fox did not seed AA amyloidosis in a mouse model. © 2017 The Protein Society.
NASA Astrophysics Data System (ADS)
Alaniz Rodrigues, Marcos; Dumont, Luiz Felipe Cestari; dos Santos, Cléverson Rannieri Meira; D'Incao, Fernando; Weiss, Steven; Froufe, Elsa
2017-10-01
For the first time, a molecular approach was used to evaluate the phylogenetic structure of the disjunct native American distribution of the blue crab Callinectes sapidus. Population structure was investigated by sequencing 648bp of the Cytochrome oxidase subunit 1 (COI), in a total of 138 sequences stemming from individual samples from both the northern and southern hemispheres of the Western Atlantic distribution of the species. A Bayesian approach was used to construct a phylogenetic tree for all samples, and a 95% confidence parsimony network was created to depict the relationship among haplotypes. Results revealed two highly distinct lineages, one containing all samples from the United States and some from Brazil (lineage 1) and the second restricted to Brazil (lineage 2). In addition, gene flow (at least for females) was detected among estuaries at local scales and there is evidence for shared haplotypes in the south. Furthermore, the findings of this investigation support the contemporary introduction of haplotypes that have apparently spread from the south to the north Atlantic.
NASA Technical Reports Server (NTRS)
Wilson, P. R.; Rees, D. E.; Beckers, J. M.; Brown, D. R.
1972-01-01
Two independent sets of high resolution time series spectra of the Ca II H and K emission obtained at the Solar Tower and at the Big Dome of the Sacramento Peak Observatory on September 11th, 1971 are reported. The evolutionary behavior of the emission first reported by Wilson and Evans is confirmed, but the detail of the evolution is found to be more complex. In one case, a doubly peaked feature showing some K3 emission evolves into a single K2 (red) peak with no K3 emission. Coincidentally, a neighboring doubly peaked feature evolves to a very strong blue peak. In an entirely independent sequence a doubly peaked feature evolves into a single red peak. The K2 emission then fades completely although the continuum threads are still strong. Finally a strong K2 blue peak appears. It is concluded that the observed evolution of the K2 emission is due to temporal variations in the physical conditions which give rise to them.
Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir; Brembu, Tore; Bones, Atle M
2014-01-01
Due to the selective attenuation of solar light and the absorption properties of seawater and seawater constituents, free-floating photosynthetic organisms have to cope with rapid and unpredictable changes in both intensity and spectral quality. We have studied the transcriptional, metabolic and photo-physiological responses to light of different spectral quality in the marine diatom Phaeodactylum tricornutum through time-series studies of cultures exposed to equal doses of photosynthetically usable radiation of blue, green and red light. The experiments showed that short-term differences in gene expression and profiles are mainly light quality-dependent. Transcription of photosynthesis-associated nuclear genes was activated mainly through a light quality-independent mechanism likely to rely on chloroplast-to-nucleus signaling. In contrast, genes encoding proteins important for photoprotection and PSII repair were highly dependent on a blue light receptor-mediated signal. Changes in energy transfer efficiency by light-harvesting pigments were spectrally dependent; furthermore, a declining trend in photosynthetic efficiency was observed in red light. The combined results suggest that diatoms possess a light quality-dependent ability to activate photoprotection and efficient repair of photodamaged PSII. In spite of approximately equal numbers of PSII-absorbed quanta in blue, green and red light, the spectral quality of light is important for diatom responses to ambient light conditions.
The blue globular pattern in dermoscopy.
Roberti, V; Devirgiliis, V; Curzio, M; Gobbi, S; Coppola, R; Calvieri, S; Panasiti, V
2013-01-01
Seborrheic keratosis (SK) is a frequent benign epithelial skin tumor. Generally its diagnosis is clinical, however SK can sometimes clinically simulate a melanocytic lesion; therefore we need dermoscopy to reach a correct diagnosis. Milia-like cysts and comedo-like openings are the common dermoscopic features of SK, but it is not a rare finding that SK can display one or more dermoscopic patterns suggestive of a melanocytic origin. We describe a case series of SKs with a blue globular pattern simulating a melanocytic lesion. We retrospectively evaluated 224 SKs seen during 2011 at the Dermatoscopy Unit of the Department of Dermatology, University of Rome 'Sapienza'. Five SKs showed a blue globular pattern, without the SK main features generally seen in dermoscopy; globules were multiple, round or oval, well-demarcated, small and medium-sized, blue-colored and equally distributed within the lesion. Histopathologic examination was consistent with acanthotic SK. Identification of the blue globular pattern can be helpful for the dermoscopic diagnosis of SK, especially when its common dermoscopic features are absent. Copyright © 2013 S. Karger AG, Basel.
Marennine, Promising Blue Pigments from a Widespread Haslea Diatom Species Complex
Gastineau, Romain; Turcotte, François; Pouvreau, Jean-Bernard; Morançais, Michèle; Fleurence, Joël; Windarto, Eko; Semba Prasetiya, Fiddy; Arsad, Sulastri; Jaouen, Pascal; Babin, Mathieu; Coiffard, Laurence; Couteau, Céline; Bardeau, Jean-François; Jacquette, Boris; Leignel, Vincent; Hardivillier, Yann; Marcotte, Isabelle; Bourgougnon, Nathalie; Tremblay, Réjean; Deschênes, Jean-Sébastien; Badawy, Hope; Pasetto, Pamela; Davidovich, Nikolai; Hansen, Gert; Dittmer, Jens; Mouget, Jean-Luc
2014-01-01
In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting. A method to extract and purify marennine has been developed, but its chemical structure could hitherto not be resolved. For decades, H. ostrearia was the only organism known to produce marennine, and can be found worldwide. Our knowledge about H. ostrearia-like diatom biodiversity has recently been extended with the discovery of several new species of blue diatoms, the recently described H. karadagensis, H. silbo sp. inedit. and H. provincialis sp. inedit. These blue diatoms produce different marennine-like pigments, which belong to the same chemical family and present similar biological activities. Aside from being a potential source of natural blue pigments, H. ostrearia-like diatoms thus present a commercial potential for aquaculture, cosmetics, food and health industries. PMID:24879542
WFPC2 Observations of the URSA Minor Dwarf Spheroidal Galaxy
NASA Technical Reports Server (NTRS)
Mighell, Kenneth J.; Burke, Christopher J.
1999-01-01
We present our analysis of archival Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) observations in F555W (approximately V) and F814W (approximately I) of the central region of the Ursa Minor dwarf spheroidal galaxy. The V versus V - I color-magnitude diagram features a sparsely populated blue horizontal branch, a steep thin red giant branch, and a narrow subgiant branch. The main sequence reaches approximately 2 magnitudes below the main-sequence turnoff (V(sup UMi, sub TO) approximately equals 23.27 +/- 0.11 mag) of the median stellar population. We compare the fiducial sequence of the Galactic globular cluster M92 (NGC 6341). The excellent match between Ursa Minor and M92 confirms that the median stellar population of the UMi dSph galaxy is metal poor ([Fe/H](sub UMi) approximately equals [Fe/H](sub M92) approximately equals -2.2 dex) and ancient (age(sub UMi)approximately equalsage(sub M92) approximately equals 14 Gyr). The B - V reddening and the absorption in V are estimated to be E(B - V) = 0.03 +/- 0.01 mag and A(sup UMi, sub V) = 0.09 +/- 0.03 mag. A new estimate of the distance modulus of Ursa Minor, (m - M)(sup UMi, sub 0) = 19.18 +/- 0.12 mag, has been derived based on fiducial-sequence fitting M92 [DELTA.V(sub UMi - M92) = 4.60 +/- 0.03 mag and DELTA(V - I)(sub UMi - M92) = 0.010 +/- 0.005 mag] and the adoption of the apparent V distance modulus for M92 of (m - M)(sup M92, sub V) = 14.67 +/- 0.08 mag (Pont et al. 1998, A&A, 329, 87). The Ursa Minor dwarf spheroidal galaxy is then at a distance of 69 +/- 4 kpc from the Sun. These HST observations indicate that Ursa Minor has had a very simple star formation history consisting mainly of a single major burst of star formation about 14 Gyr ago which lasted approximately < 2 Gyr. While we may have missed minor younger stellar populations due to the small field-of-view of the WFPC2 instrument, these observations clearly show that most of the stars in the central region Ursa Minor dwarf spheroidal galaxy are ancient. If the ancient Galactic globular clusters, like M92, formed concurrently with the early formation of the Milky Way galaxy itself, then the Ursa Minor dwarf spheroidal is probably as old as the Milky Way.
A Dynamic Model for Prediction of Psoriasis Management by Blue Light Irradiation
Félix Garza, Zandra C.; Liebmann, Joerg; Born, Matthias; Hilbers, Peter A. J.; van Riel, Natal A. W.
2017-01-01
Clinical investigations prove that blue light irradiation reduces the severity of psoriasis vulgaris. Nevertheless, the mechanisms involved in the management of this condition remain poorly defined. Despite the encouraging results of the clinical studies, no clear guidelines are specified in the literature for the irradiation scheme regime of blue light-based therapy for psoriasis. We investigated the underlying mechanism of blue light irradiation of psoriatic skin, and tested the hypothesis that regulation of proliferation is a key process. We implemented a mechanistic model of cellular epidermal dynamics to analyze whether a temporary decrease of keratinocytes hyper-proliferation can explain the outcome of phototherapy with blue light. Our results suggest that the main effect of blue light on keratinocytes impacts the proliferative cells. They show that the decrease in the keratinocytes proliferative capacity is sufficient to induce a transient decrease in the severity of psoriasis. To study the impact of the therapeutic regime on the efficacy of psoriasis treatment, we performed simulations for different combinations of the treatment parameters, i.e., length of treatment, fluence (also referred to as dose), and intensity. These simulations indicate that high efficacy is achieved by regimes with long duration and high fluence levels, regardless of the chosen intensity. Our modeling approach constitutes a framework for testing diverse hypotheses on the underlying mechanism of blue light-based phototherapy, and for designing effective strategies for the treatment of psoriasis. PMID:28184200
Duicu, Oana M; Privistirescu, Andreea; Wolf, Adrian; Petruş, Alexandra; Dănilă, Maria D; Raţiu, Corina D; Muntean, Danina M; Sturza, Adrian
2017-11-01
Diabetic cardiomyopathy has been systematically associated with compromised mitochondrial energetics and increased generation of reactive oxygen species (ROS) that underlie its progression to heart failure. Methylene blue is a redox drug with reported protective effects mainly on brain mitochondria. The purpose of the present study was to characterize the effects of acute administration of methylene blue on mitochondrial respiration, H 2 O 2 production, and calcium sensitivity in rat heart mitochondria isolated from healthy and 2 months (streptozotocin-induced) diabetic rats. Mitochondrial respiratory function was assessed by high-resolution respirometry. H 2 O 2 production and calcium retention capacity were measured spectrofluorimetrically. The addition of methylene blue (0.1 μmol·L -1 ) elicited an increase in oxygen consumption of mitochondria energized with complex I and II substrates in both normal and diseased mitochondria. Interestingly, methylene blue elicited a significant increase in H 2 O 2 release in the presence of complex I substrates (glutamate and malate), but had an opposite effect in mitochondria energized with complex II substrate (succinate). No changes in the calcium retention capacity of healthy or diabetic mitochondria were found in the presence of methylene blue. In conclusion, in cardiac mitochondria isolated from diabetic and nondiabetic rat hearts, methylene blue improved respiratory function and elicited a dichotomic, substrate-dependent effect on ROS production.
NASA Astrophysics Data System (ADS)
Bär, Rudolf E.; Weigel, Anna K.; Sartori, Lia F.; Oh, Kyuseok; Koss, Michael; Schawinski, Kevin
2017-04-01
In order to perform a more complete census of active galactic nuclei (AGN) in the local Universe, we investigate the use of the He II λ4685 emission line diagnostic diagram by Shirazi & Brinchmann (2012) in addition to the standard methods based on other optical emission lines. The He II-based diagnostics is more sensitive to AGN ionization in the presence of strong star formation than conventional line diagnostics. We survey a magnitude-limited sample of 63 915 galaxies from the Sloan Digital Sky Survey Data Release 7 at 0.02 < z < 0.05 and use both the conventional BPT emission line diagnostic diagrams, as well as the He II diagram to identify AGN. In this sample, 1075 galaxies are selected as AGN using the BPT diagram, while additional 234 galaxies are identified as AGN using the He II diagnostic diagram, representing a 22 per cent increase of AGN in the parent galaxy sample. We explore the host galaxy properties of these new He II-selected AGN candidates and find that they are most common in star-forming galaxies on the blue cloud and on the main sequence where ionization from star formation is most likely to mask AGN emission in the BPT lines. We note in particular a high He II AGN fraction in galaxies above the high-mass end of the main sequence where quenching is expected to occur. We use archival Chandra observations to confirm the AGN nature of candidates selected through He II-based diagnostic. Finally, we discuss how this technique can help inform galaxy/black hole coevolution scenarios.
Mishra, Sanjiv K; Shrivastav, Anupama; Maurya, Rahulkumar R; Patidar, Shailesh K; Haldar, Soumya; Mishra, Sandhya
2012-01-01
The isolated cyanobacterium containing biopigments like chlorophyll-a, phycoerythrin, phycocyanin, and carotenoid was cultured under different quality of light modes to ascertain biomass and pigment productivity. On the basis of 16S rRNA gene sequence, the isolate was identified as Pseudanabaena sp. Maximum biomass concentration obtained in white-, blue-, and green-light was 0.82, 0.94, and 0.89 g/L, respectively. It was observed that maximum phycoerythrin production was in green light (39.2 mg/L), ensued by blue light (32.2 mg/L), while phycocyanin production was maximum in red light (10.9 mg/L). In yellow light, pigment production as well as the growth rate gradually declined after 12 days. Carotenoid production decreased in blue-, white-, and red-light after 15 days, while in green light it had increased gradually. The present communication suggests that Pseudanabaena sp. can be used for commercial production of phycoerythrin when grown under green light. Copyright © 2011 Elsevier Inc. All rights reserved.
Árnason, Úlfur; Kumar, Vikas
2018-01-01
Reconstructing the evolution of baleen whales (Mysticeti) has been problematic because morphological and genetic analyses have produced different scenarios. This might be caused by genomic admixture that may have taken place among some rorquals. We present the genomes of six whales, including the blue whale (Balaenoptera musculus), to reconstruct a species tree of baleen whales and to identify phylogenetic conflicts. Evolutionary multilocus analyses of 34,192 genome fragments reveal a fast radiation of rorquals at 10.5 to 7.5 million years ago coinciding with oceanic circulation shifts. The evolutionarily enigmatic gray whale (Eschrichtius robustus) is placed among rorquals, and the blue whale genome shows a high degree of heterozygosity. The nearly equal frequency of conflicting gene trees suggests that speciation of rorqual evolution occurred under gene flow, which is best depicted by evolutionary networks. Especially in marine environments, sympatric speciation might be common; our results raise questions about how genetic divergence can be established. PMID:29632892
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aylor, J.G. Jr.; Tull, J.F.
1993-03-01
The Lower Cambrian Chilhowee Group (CG) along the Blue Ridge (BR) foreland boundary may also be represented in more internal parts of the orogen. The relative palinspastic positions of these more internal CG( ) sequences are poorly constrained, but they are believed to represent more outboard facies than those along the frontal BR. Although correlation with CG rocks of the frontal BR is indefinite due to metamorphism and polydeformation, correlative sequences may include the cover of the Corbin and Salem Church gneisses (Pinelog Fm.), Grandfather Mountain window, Murphy belt (MB) (Hiwassee River Group), Tallulah and Toxaway domes (TTD) (quartzite-schist membermore » of the Tallulah Falls Fm.), Pine Mountain window (Hollis Quartzite), and Sauratown Mountains window (Hogan Creek and Sauratown Fms.). The CG is generally bounded on the west by the Great Smoky fault. Siliciclastics of the CG represent stacked, coarsening upward sequences, separated by transgressive facies, and capped by a highstand of the Shady Dolomite or its equivalents. CG correlations in the Kahatchee Mountain Group of the Talladega belt and the siliciclastics in the Hiwassee River Group of the MB are supported by fossil constraints. Other units are correlated with CG based upon intimate associations with marble believed to be equivalent to the overlying Lower Cambrian Shady Dolomite, or upon presumed uncomformable relationships above Grenville basement. The CG averages about 1,260 meters thickness at the frontal BR, whereas lower siliciclastics in the MB average 1,830 meters. The Pinelog Fm. is up to 600 meters thick. The Hollis Quartzite is approximately 325 meters thick, and the estimated thickness of the quartz-schist member at Tallulah Falls is up to 900 meters. More distal siliciclastics of the central BR in the MB and distal siliciclastics overlying basement were deposited farther out on the shelf as stratigraphic, litho-facies equivalents of shallower marine and continental deposits of the CG.« less
Chen, Wang; Li, Yan; Wang, Qiang; Wang, Nan; Wu, Yunfeng
2014-01-01
Wheat blue dwarf (WBD) disease is an important disease that has caused heavy losses in wheat production in northwestern China. This disease is caused by WBD phytoplasma, which is transmitted by Psammotettix striatus. Until now, no genome information about WBD phytoplasma has been published, seriously restricting research on this obligate pathogen. In this paper, we report a new sequencing and assembling strategy for phytoplasma genome projects. This strategy involves differential centrifugation, pulsed-field gel electrophoresis, whole genome amplification, shotgun sequencing, de novo assembly, screening of contigs from phytoplasma and the connection of phytoplasma contigs. Using this scheme, the WBD phytoplasma draft genome was obtained. It was comprised of six contigs with a total size of 611,462 bp, covering ∼94% of the chromosome. Five-hundred-twenty-five protein-coding genes, two operons for rRNA genes and 32 tRNA genes were identified. Comparative genome analyses between WBD phytoplasma and other phytoplasmas were subsequently carried out. The results showed that extensive arrangements and inversions existed among the WBD, OY-M and AY-WB phytoplasma genomes. Most protein-coding genes in WBD phytoplasma were found to be homologous to genes from other phytoplasmas; only 22 WBD-specific genes were identified. KEGG pathway analysis indicated that WBD phytoplasma had strongly reduced metabolic capabilities. However, 46 transporters were identified, which were involved with dipeptides/oligopeptides, spermidine/putrescine, cobalt and Mn/Zn transport, and so on. A total of 37 secreted proteins were encoded in the WBD phytoplasma chromosome and plasmids. Of these, three secreted proteins were similar to the reported phytoplasma virulence factors TENGU, SAP11 and SAP54. In addition, WBD phytoplasma possessed several proteins that were predicted to play a role in its adaptation to diverse environments. These results will provide clues for research on the pathogenic mechanisms of WBD phytoplasma and will also provide a perspective about the genome sequencing of other phytoplasmas and obligate organisms. PMID:24798075
Shabangu, Fannie W.; Yemane, Dawit; Stafford, Kathleen M.; Ensor, Paul; Findlay, Ken P.
2017-01-01
Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC), latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a) were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of Antarctic blue whales is important in improving the management and conservation of this highly depleted species. PMID:28222124
Shabangu, Fannie W; Yemane, Dawit; Stafford, Kathleen M; Ensor, Paul; Findlay, Ken P
2017-01-01
Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC), latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a) were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of Antarctic blue whales is important in improving the management and conservation of this highly depleted species.
NASA Astrophysics Data System (ADS)
Hansen, C. J.; Jofré, P.; Koch, A.; McWilliam, A.; Sneden, C. S.
2017-02-01
Blue metal-poor (BMP) stars are main sequence stars that appear bluer and more luminous than normal turnoff stars. They were originally singled out by using B-V and U-B colour cuts.Early studies found that a larger fraction of field BMP stars were binaries compared to normal halo stars. Thus, BMP stars are ideal field blue straggler candidates for investigating internal stellar evolution processes and binary interaction. In particular, the presence or depletion in lithium in their spectra is a powerful indicator of their origin. They are either old, halo blue stragglers experiencing internal mixing processes or mass transfer (Li-depletion), or intermediate-age, single stars of possibly extragalactic origin (2.2 dex halo plateau Li). However, we note that internal mixing processes can lead to an increased level of Li. Hence, this study combines photometry and spectroscopy to unveil the origin of various BMP stars. We first show how to separate binaries from young blue stars using photometry, metallicity and lithium. Using a sample of 80 BMP stars (T > 6300 K), we find that 97% of the BMP binaries have V-Ks0 < 1.08 ± 0.03, while BMP stars that are not binaries lie above this cut in two thirds of the cases. This cut can help classify stars that lack radial velocities from follow-up observations. We then trace the origin of two BMP stars from the photometric sample by conducting a full chemical analysis using new high-resolution and high signal-to-noise spectra. Based on their radial velocities, Li, α and s- and r-process abundances we show that BPS CS22874-042 is a single star (A(Li) = 2.38 ± 0.10 dex) while with A(Li)= 2.23 ± 0.07 dex CD-48 2445 is a binary, contrary to earlier findings. Our analysis emphasises that field blue stragglers can be segregated from single metal-poor stars, using (V-Ks) colours with a fraction of single stars polluting the binary sample, but not vice versa. These two groups can only be properly separated by using information from stellar spectra, illustrating the need for accurate and precise stellar parameters and high-resolution, high-S/N spectra in order to fully understand and classify this intriguing class of stars. Our high-resolution spectrum analysis confirms the findings from the colour cuts and shows that CS 22874-042 is single, while CD -48 2445 is most likely a binary. Moreover, the stellar abundances show that both stars formed in situ; CS 22874-042 carries traces of massive star enrichment and CD -48 2445 shows indications of AGB mass transfer mixed with gases ejected possibly from neutron star mergers. Based on UVES archive data 077.B-0507 and 090.B-0605. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. Full Table 4 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/598/A54
Londraville, R L; Cramer, T D; Franck, J P; Tullis, A; Block, B A
2000-10-01
Complete cDNAs for the fast-twitch Ca2+ -ATPase isoform (SERCA 1) were cloned and sequenced from blue marlin (Makaira nigricans) extraocular muscle (EOM). Complete cDNAs for SERCA 1 were also cloned from fast-twitch skeletal muscle of the same species. The two sequences are identical over the coding region except for the last five codons on the carboxyl end; EOM SERCA 1 cDNA codes for 996 amino acids and the fast-twitch cDNAs code for 991 aa. Phylogenetic analysis revealed that EOM SERCA 1 clusters with an isoform of Ca2+ -ATPase normally expressed in early development of mammals (SERCA 1B). This is the first report of SERCA 1B in an adult vertebrate. RNA hybridization assays indicate that 1B expression is limited to extraocular muscles. Because EOM gives rise to the thermogenic heater organ in marlin, we investigated whether SERCA 1B may play a role in heat generation, or if 1B expression is common in EOM among vertebrates. Chicken also expresses SERCA 1B in EOM, but rat expresses SERCA 1A; because SERCA 1B is not specific to heater tissue we conclude it is unlikely that it plays a specific role in intracellular heat production. Comparative sequence analysis does reveal, however, several sites that may be the source of functional differences between fish and mammalian SERCAs.
Borsa, Philippe; Arlyza, Irma S; Chen, Wei-Jen; Durand, Jean-Dominique; Meekan, Mark G; Shen, Kang-Ning
2013-04-01
The maskray from New Caledonia, Neotrygon trigonoides Castelnau, 1873, has been recently synonymized with the blue-spotted maskray, N. kuhlii (Müller and Henle, 1841), a species with wide Indo-West Pacific distribution, but the reasons for this are unclear. Blue-spotted maskray specimens were collected from the Indian Ocean (Tanzania, Sumatra) and the Coral Triangle (Indonesia, Taiwan, and West Papua), and N. trigonoides specimens were collected from New Caledonia (Coral-Sea). Their partial COI gene sequences were generated to expand the available DNA-barcode database on this species, which currently comprises homologous sequences from Ningaloo Reef, the Coral Triangle and the Great Barrier Reef (Coral-Sea). Spotting patterns were also compared across regions. Haplotypes from the Coral-Sea formed a haplogroup phylogenetically distinct from all other haplotypes sampled in the Indo-West Pacific. No clear-cut geographic composition relative to DNA-barcodes or spotting patterns was apparent in N. kuhlii samples across the Indian Ocean and the Coral Triangle. The New Caledonian maskray had spotting patterns markedly different from all the other samples. This, added to a substantial level of net nucleotide divergence (2.6%) with typical N. kuhlii justifies considering the New Caledonian maskray as a separate species, for which we propose to resurrect the name Neotrygon trigonoides. Copyright © 2013. Published by Elsevier SAS.
Wang, Hsiang-Chen; Chen, Meng-Chu; Lin, Yen-Sheng; Lu, Ming-Yen; Lin, Kuang-I; Cheng, Yung-Chen
2017-11-09
The features of eight-period In 0.2 Ga 0.8 N/GaN quantum wells (QWs) with silicon (Si) doping in the first two to five quantum barriers (QBs) in the growth sequence of blue light-emitting diodes (LEDs) are explored. Epilayers of QWs' structures are grown on 20 pairs of In 0.02 Ga 0.98 N/GaN superlattice acting as strain relief layers (SRLs) on patterned sapphire substrates (PSSs) by a low-pressure metal-organic chemical vapor deposition (LP-MOCVD) system. Temperature-dependent photoluminescence (PL) spectra, current versus voltage (I-V) curves, light output power versus injection current (L-I) curves, and images of high-resolution transmission electron microscopy (HRTEM) of epilayers are measured. The consequences show that QWs with four Si-doped QBs have larger carrier localization energy (41 meV), lower turn-on (3.27 V) and breakdown (- 6.77 V) voltages, and higher output power of light of blue LEDs at higher injection current than other samples. Low barrier height of QBs in a four-Si-doped QB sample results in soft confinement potential of QWs and lower turn-on and breakdown voltages of the diode. HRTEM images give the evidence that this sample has relatively diffusive interfaces of QWs. Uniform spread of carriers among eight QWs and superior localization of carriers in each well are responsible for the enhancement of light output power, in particular, for high injection current in the four-Si-doped QB sample. The results demonstrate that four QBs of eight In 0.2 Ga 0.8 N/GaN QWs with Si doping not only reduce the quantum-confined Stark effect (QCSE) but also improve the distribution and localization of carriers in QWs for better optical performance of blue LEDs.
NASA Astrophysics Data System (ADS)
Wang, Hsiang-Chen; Chen, Meng-Chu; Lin, Yen-Sheng; Lu, Ming-Yen; Lin, Kuang-I.; Cheng, Yung-Chen
2017-11-01
The features of eight-period In0.2Ga0.8N/GaN quantum wells (QWs) with silicon (Si) doping in the first two to five quantum barriers (QBs) in the growth sequence of blue light-emitting diodes (LEDs) are explored. Epilayers of QWs' structures are grown on 20 pairs of In0.02Ga0.98N/GaN superlattice acting as strain relief layers (SRLs) on patterned sapphire substrates (PSSs) by a low-pressure metal-organic chemical vapor deposition (LP-MOCVD) system. Temperature-dependent photoluminescence (PL) spectra, current versus voltage ( I- V) curves, light output power versus injection current ( L- I) curves, and images of high-resolution transmission electron microscopy (HRTEM) of epilayers are measured. The consequences show that QWs with four Si-doped QBs have larger carrier localization energy (41 meV), lower turn-on (3.27 V) and breakdown (- 6.77 V) voltages, and higher output power of light of blue LEDs at higher injection current than other samples. Low barrier height of QBs in a four-Si-doped QB sample results in soft confinement potential of QWs and lower turn-on and breakdown voltages of the diode. HRTEM images give the evidence that this sample has relatively diffusive interfaces of QWs. Uniform spread of carriers among eight QWs and superior localization of carriers in each well are responsible for the enhancement of light output power, in particular, for high injection current in the four-Si-doped QB sample. The results demonstrate that four QBs of eight In0.2Ga0.8N/GaN QWs with Si doping not only reduce the quantum-confined Stark effect (QCSE) but also improve the distribution and localization of carriers in QWs for better optical performance of blue LEDs.
Mueller, Jakob C; Kuhl, Heiner; Timmermann, Bernd; Kempenaers, Bart
2016-03-01
Decoding genomic sequences and determining their variation within populations has potential to reveal adaptive processes and unravel the genetic basis of ecologically relevant trait variation within a species. The blue tit Cyanistes caeruleus--a long-time ecological model species--has been used to investigate fitness consequences of variation in mating and reproductive behaviour. However, very little is known about the underlying genetic changes due to natural and sexual selection in the genome of this songbird. As a step to bridge this gap, we assembled the first draft genome of a single blue tit, mapped the transcriptome of five females and five males to this reference, identified genomewide variants and performed sex-differential expression analysis in the gonads, brain and other tissues. In the gonads, we found a high number of sex-biased genes, and of those, a similar proportion were sex-limited (genes only expressed in one sex) in males and females. However, in the brain, the proportion of female-limited genes within the female-biased gene category (82%) was substantially higher than the proportion of male-limited genes within the male-biased category (6%). This suggests a predominant on-off switching mechanism for the female-limited genes. In addition, most male-biased genes were located on the Z-chromosome, indicating incomplete dosage compensation for the male-biased genes. We called more than 500,000 SNPs from the RNA-seq data. Heterozygote detection in the single reference individual was highly congruent between DNA-seq and RNA-seq calling. Using information from these polymorphisms, we identified potential selection signals in the genome. We list candidate genes which can be used for further sequencing and detailed selection studies, including genes potentially related to meiotic drive evolution. A public genome browser of the blue tit with the described information is available at http://public-genomes-ngs.molgen.mpg.de. © 2015 John Wiley & Sons Ltd.
Meesters, Ybe; Winthorst, Wim H; Duijzer, Wianne B; Hommes, Vanja
2016-02-18
The discovery of a novel photoreceptor in the retinal ganglion cells with a highest sensitivity of 470-490 nm blue light has led to research on the effects of short-wavelength light in humans. Several studies have explored the efficacy of monochromatic blue or blue-enriched light in the treatment of SAD. In this study, a comparison has been made between the effects of broad-wavelength light without ultraviolet (UV) wavelengths compared to narrow-band blue light in the treatment of sub-syndromal seasonal affective disorder (Sub-SAD). In a 15-day design, 48 participants suffering from Sub-SAD completed 20-minute sessions of light treatment on five consecutive days. 22 participants were given bright white-light treatment (BLT, broad-wavelength light without UV 10 000 lux, irradiance 31.7 Watt/m(2)) and 26 participants received narrow-band blue light (BLUE, 100 lux, irradiance 1.0 Watt/m(2)). All participants completed daily and weekly questionnaires concerning mood, activation, sleep quality, sleepiness and energy. Also, mood and energy levels were assessed by means of the SIGH-SAD, the primary outcome measure. On day 15, SIGH-SAD ratings were significantly lower than on day 1 (BLT 54.8 %, effect size 1.7 and BLUE 50.7 %, effect size 1.9). No statistically significant differences were found on the main outcome measures. Light treatment is an effective treatment for Sub-SAD. The use of narrow-band blue-light treatment is equally effective as bright white-light treatment. This study was registered in the Dutch Trial Register (Nederlands Trial Register TC = 4342 ) (20-12-2013).
NASA Astrophysics Data System (ADS)
Edmonds, Peter D.; Gilliland, Ronald L.; Heinke, Craig O.; Grindlay, Jonathan E.
2003-10-01
We report in this study of 47 Tucanae the largest number of optical identifications of X-ray sources yet obtained in a single globular cluster. Using deep Chandra ACIS-I imaging and extensive Hubble Space Telescope studies with Wide Field Planetary Camera 2 (WFPC2; including a 120 orbit program giving superb V and I images), we have detected optical counterparts to at least 22 cataclysmic variables (CVs) and 29 chromospherically active binaries (BY Dra and RS CVn systems) in 47 Tuc. These identifications are all based on tight astrometric matches between X-ray sources and objects with unusual (non-main-sequence [non-MS]) optical colors and/or optical variability. Several other CVs and active binaries have likely been found, but these have marginal significance because of larger offsets between the X-ray and optical positions, or colors and variability that are not statistically convincing. These less secure optical identifications are not subsequently discussed in detail. In the U versus U-V color-magnitude diagram (CMD), where the U band corresponds to either F336W or F300W, the CVs all show evidence for blue colors compared with the MS, but most of them fall close to the main sequence in the V versus V-I CMD, showing that the secondary stars dominate the optical light. The X-ray-detected active binaries have magnitude offsets above the MS (in both the U versus U-V or V versus V-I CMDs) that are indistinguishable from those of the much larger sample of optical variables (eclipsing and contact binaries and BY Dra variables) detected in the recent WFPC2 studies of Albrow et al. We also present the results of a new, deeper search for optical companions to millisecond pulsars (MSPs). One possible optical companion to an MSP (47 Tuc T) was found, adding to the two optical companions already known. Finally, we study several blue stars with periodic variability from Albrow et al. that show little or no evidence for X-ray emission. The optical colors of these objects differ from those of 47 Tuc (and field) CVs. An accompanying paper will present time series results for these optical identifications and will discuss X-ray-to-optical flux ratios, spatial distributions, and an overall interpretation of the results. Based on observations with the NASA/ESA Hubble Space Telescope obtained at STScI, which is operated by AURA, Inc., under NASA contract NAS 5-26555.
Wu, Kailong; Wang, Zian; Zhan, Lisi; Zhong, Cheng; Gong, Shaolong; Xie, Guohua; Yang, Chuluo
2018-04-05
Two new blue emitters, i.e., bis-[2-(9,9-dimethyl-9,10-dihydroacridine)-phenyl]-sulfone ( o-ACSO2) and bis-[3-(9,9-dimethyl-9,10-dihydroacridine)-phenyl]-sulfone ( m-ACSO2), with reserved fine thermally activated delayed fluorescent (TADF) nature and simply tuned thermal and optoelectronic properties, were synthesized by isomer engineering. The meta-linking compound, i.e., m-ACSO2, obtains the highest photoluminescence quantum yield with a small singlet-triplet energy gap, a moderate delayed fluorescent lifetime, excellent solubility, and neat film homogeneity. Due to its unique aggregation-induced emission (AIE) character, neat film-based heterojunction-like organic light-emitting diodes (OLEDs) are achievable. By inserting an excitonic inert exciton-blocking layer, the PN heterojunction-like emission accompanied by intefacial exciplex was shifted to a homojunction-like channel mainly from the AIE emitter itself, providing a new tactic to generate efficient blue color from neat films. The solution-processed nondoped sky-blue OLED employing m-ACSO2 as emitter with homojunction-like emission achieved a maximum external quantum efficiency of 17.2%. The design strategies presented herein provide practical methods to construct efficient blue TADF dyes and realize high-performance blue TADF devices.
A Revolutionary Approach for the Development of Future Ground Combat System Specifications
2013-09-01
35 B. PHYSICAL PROPERTIES FOR BLUE AGENTS .............................. 38 1. Bradley M2A3 ...available, Wikipedia. B. PHYSICAL PROPERTIES FOR BLUE AGENTS 1. Bradley M2A3 The main ground combat vehicle for the scenario is the Bradley M2A3 ...Total Men Men per Agent MANA Agents 4 x Bradley M2A3 12 3 4 4 x Bradley infantry 28 1 28 Platoon Abrams SEP M1A2 16 4 4 2 x AH64-D attack
for storage. Go back stage graphic: vertical blue rule Main stage: See through car with battery , engine, generator, power split device, and electric motor visible. The car is moving. There are arrows flowing from the gasoline engine to the generator to the battery. Main stage: See through car with battery
automatically. Go back stage graphic: vertical blue rule Main stage: See through car with battery, engine, and electric motor visible. The car is stopped at an intersection. Main stage: See through car with battery , engine, and electric motor visible. The car is stopped at an intersection. Battery: The battery stores
: vertical blue rule Main stage: See through car with battery, engine, and electric starter/generator visible . The car is stopped at an intersection. Main stage: See through car with battery, engine, and electric starter/generator visible. The car is stopped at an intersection. Battery: The battery is used to store
blue rule Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is moving at a low speed. There are arrows flowing from the battery to the electric motor to the power split device to the front wheels. Main stage: See through car with battery
: vertical blue rule Main stage: See through car with battery, engine, generator, power split device, and electric motor visible. The car is stopped at an intersection. Main stage: See through car with battery , engine, generator, power split device, and electric motor visible. The car is stopped at an intersection
motor slows the vehicle down. Go to next stage graphic: vertical blue rule Main stage: See through car with battery, engine, and electric motor visible. The car is decelerating. There are arrows flowing from the front wheels to the electric motor to the battery. Main stage: See through car with battery
The K2 M67 Study: A Curiously Young Star in an Eclipsing Binary in an Old Open Cluster
NASA Astrophysics Data System (ADS)
Sandquist, Eric L.; Mathieu, Robert D.; Quinn, Samuel N.; Pollack, Maxwell L.; Latham, David W.; Brown, Timothy M.; Esselstein, Rebecca; Aigrain, Suzanne; Parviainen, Hannu; Vanderburg, Andrew; Stello, Dennis; Somers, Garrett; Pinsonneault, Marc H.; Tayar, Jamie; Orosz, Jerome A.; Bedin, Luigi R.; Libralato, Mattia; Malavolta, Luca; Nardiello, Domenico
2018-04-01
We present an analysis of a slightly eccentric (e = 0.05), partially eclipsing, long-period (P = 69.73 days) main-sequence binary system (WOCS 12009, Sanders 1247) in the benchmark old open cluster M67. Using Kepler K2 and ground-based photometry, along with a large set of new and reanalyzed spectra, we derived highly precise masses (1.111 ± 0.015 and 0.748 ± 0.005 M ⊙) and radii (1.071 ± 0.008 ± 0.003 and 0.713 ± 0.019 ± 0.026 R ⊙, with statistical and systematic error estimates) for the stars. The radius of the secondary star is in agreement with theory. The primary, however, is approximately 15% smaller than reasonable isochrones for the cluster predict. Our best explanation is that the primary star was produced from the merger of two stars, as this can also account for the nondetection of photospheric lithium and its higher temperature relative to other cluster main-sequence stars at the same V magnitude. To understand the dynamical characteristics (low measured rotational line broadening of the primary star and low eccentricity of the current binary orbit), we believe that the most probable (but not the only) explanation is the tidal evolution of a close binary within a primordial triple system (possibly after a period of Kozai–Lidov oscillations), leading to merger approximately 1 Gyr ago. This star appears to be a future blue straggler that is being revealed as the cluster ages and the most massive main-sequence stars die out. Based on observations made at Kitt Peak National Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation; with the Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5 m Tillinghast telescope, located at the Smithsonian Astrophysical Observatory’s Fred L. Whipple Observatory on Mt. Hopkins in Arizona; the HARPS-N spectrograph on the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the INAF Fundacion Galileo Galilei (Spanish Observatory of Roque de los Muchachos of the IAC); and the Las Cumbres Observatory Global Telescope network.
Evaluation of Resuspension from Propeller Wash in DoD Harbors
2016-09-01
sand , silt, clay, and dissolved fractions. Information in the middle represents the filtration sequence, information to the left are...San Diego Bay. Each metal is provided as the percentage fraction for clay (grey), silt (green), sand (red) and total (blue), the same pattern is...middle), and sand (bottom) concentrations for the three locations (see Figure 6-33
USDA-ARS?s Scientific Manuscript database
The intestinal microbiome (IM), or the community of commensal and pathogenic microbes living within the gut, have long been thought to play a large role in digestion and fish performance. Recently, high-throughput molecular sequencing has yielded insights into the importance of the IM in aquaculture...
Insights into Penicillium roqueforti Morphological and Genetic Diversity
Gillot, Guillaume; Jany, Jean-Luc; Coton, Monika; Le Floch, Gaétan; Debaets, Stella; Ropars, Jeanne; López-Villavicencio, Manuela; Dupont, Joëlle; Branca, Antoine; Giraud, Tatiana; Coton, Emmanuel
2015-01-01
Fungi exhibit substantial morphological and genetic diversity, often associated with cryptic species differing in ecological niches. Penicillium roqueforti is used as a starter culture for blue-veined cheeses, being responsible for their flavor and color, but is also a common spoilage organism in various foods. Different types of blue-veined cheeses are manufactured and consumed worldwide, displaying specific organoleptic properties. These features may be due to the different manufacturing methods and/or to the specific P. roqueforti strains used. Substantial morphological diversity exists within P. roqueforti and, although not taxonomically valid, several technological names have been used for strains on different cheeses (e.g., P. gorgonzolae, P. stilton). A worldwide P. roqueforti collection from 120 individual blue-veined cheeses and 21 other substrates was analyzed here to determine (i) whether P. roqueforti is a complex of cryptic species, by applying the Genealogical Concordance Phylogenetic Species Recognition criterion (GC-PSR), (ii) whether the population structure assessed using microsatellite markers correspond to blue cheese types, and (iii) whether the genetic clusters display different morphologies. GC-PSR multi-locus sequence analyses showed no evidence of cryptic species. The population structure analysis using microsatellites revealed the existence of highly differentiated populations, corresponding to blue cheese types and with contrasted morphologies. This suggests that the population structure has been shaped by different cheese-making processes or that different populations were recruited for different cheese types. Cheese-making fungi thus constitute good models for studying fungal diversification under recent selection. PMID:26091176
ERIC Educational Resources Information Center
Elliott, David C.
In response to growing concern about the impact on economic prosperity resulting from the low level of higher educational attainment in Maine, two bills calling for study of that issue were introduced in the 120th Maine Legislature. A commission was created to develop a plan to improve the state's level of higher educational attainment. This…
Hubble's View of Little Blue Dots
NASA Astrophysics Data System (ADS)
Kohler, Susanna
2018-02-01
The recent discovery of a new type of tiny, star-forming galaxy is the latest in a zoo of detections shedding light on our early universe. What can we learn from the unique little blue dots found in archival Hubble data?Peas, Berries, and DotsGreen pea galaxies identified by citizen scientists with Galaxy Zoo. [Richard Nowell Carolin Cardamone]As telescope capabilities improve and we develop increasingly deeper large-scale surveys of our universe, we continue to learn more about small, faraway galaxies. In recent years, increasing sensitivity first enabled the detection of green peas luminous, compact, low-mass (10 billion solar masses; compare this to the Milky Ways 1 trillion solar masses!) galaxies with high rates of star formation.Not long thereafter, we discovered galaxies that form stars similarly rapidly, but are even smaller only 330 million solar masses, spanning less than 3,000 light-years in size. These tiny powerhouses were termed blueberries for their distinctive color.Now, scientists Debra and Bruce Elmegreen (of Vassar College and IBM Research Division, respectively) report the discovery of galaxies that have even higher star formation rates and even lower masses: little blue dots.Exploring Tiny Star FactoriesThe Elmegreens discovered these unique galaxies by exploring archival Hubble data. The Hubble Frontier Fields data consist of deep images of six distant galaxy clusters and the parallel fields next to them. It was in the archival data for two Frontier Field Parallels, those for clusters Abell 2744 and MAS J0416.1-2403, that the authors noticed several galaxies that stand out as tiny, bright, blue objects that are nearly point sources.Top: a few examples of the little blue dots recently identified in two Hubble Frontier Field Parallels. Bottom: stacked images for three different groups of little blue dots. [Elmegreen Elmegreen 2017]The authors performed a search through the two Frontier Field Parallels, discovering a total of 55 little blue dots with masses spanning 105.8107.4solar masses, specific star formation rates of 10-7.4, and redshifts of 0.5 z 5.4.Exploring these little blue dots, the Elmegreens find that the galaxies sizes tend to be just a few hundred light-years across. They are gas-dominated; gas currently outweighs stars in these galaxies by perhaps a factor of five. Impressively, based on the incredibly high specific star formation rates observed in these little blue dots, they appear to have formed all of their stars in the last 1% of the age of the universe for them.An Origin for Globulars?Log-log plot of star formation rate vs. mass for the three main groups of little blue dots (red, green, and blue markers), a fourth group of candidates with different properties (brown markers), and previously discovered local blueberry galaxies. The three main groups of little blue dots appear to be low-mass analogs of blueberries. [Elmegreen Elmegreen 2017]Intriguingly, this rapid star formation might be the key to answering a long-standing question: where do globular clusters come from? The Elmegreens propose that little blue dots might actually be an explanation for the origin of these orbiting, spherical, low-metallicity clusters of stars.The authors demonstrate that, if the current star formation rates observed in little blue dots were to persist for another 50 Myr before feedback or gas exhaustion halted star production, the little blue dots could form enough stars to create clusters of roughly a million solar masses which is large enough to explain the globular clusters we observe today.If little blue dots indeed rapidly produced such star clusters in the past, the clusters could later be absorbed into the halos of todays spiral and elliptical galaxies, appearing to us as the low-metallicity globular clusters that orbit large galaxies today.CitationDebra Meloy Elmegreen and Bruce G. Elmegreen 2017 ApJL 851 L44. doi:10.3847/2041-8213/aaa0ce
van Lis, Robert; Atteia, Ariane; Mendoza-Hernández, Guillermo; González-Halphen, Diego
2003-01-01
Pure mitochondria of the photosynthetic alga Chlamydomonas reinhardtii were analyzed using blue native-polyacrylamide gel electrophoresis (BN-PAGE). The major oxidative phosphorylation complexes were resolved: F1F0-ATP synthase, NADH-ubiquinone oxidoreductase, ubiquinol-cytochrome c reductase, and cytochrome c oxidase. The oligomeric states of these complexes were determined. The F1F0-ATP synthase runs exclusively as a dimer, in contrast to the C. reinhardtii chloroplast enzyme, which is present as a monomer and subcomplexes. The sequence of a 60-kD protein, associated with the mitochondrial ATP synthase and with no known counterpart in any other organism, is reported. This protein may be related to the strong dimeric character of the algal F1F0-ATP synthase. The oxidative phosphorylation complexes resolved by BN-PAGE were separated into their subunits by second dimension sodium dodecyl sulfate-PAGE. A number of polypeptides were identified mainly on the basis of their N-terminal sequence. Core I and II subunits of complex III were characterized, and their proteolytic activities were predicted. Also, the heterodimeric nature of COXIIA and COXIIB subunits in cytochrome c oxidase was demonstrated. Other mitochondrial proteins like the chaperone HSP60, the alternative oxidase, the aconitase, and the ADP/ATP carrier were identified. BN-PAGE was also used to approach the analysis of the major chloroplast protein complexes of C. reinhardtii. PMID:12746537
VizieR Online Data Catalog: NGC 6802 dwarf cluster members and non-members (Tang+, 2017)
NASA Astrophysics Data System (ADS)
Tang, B.; Geisler, D.; Friel, E.; Villanova, S.; Smiljanic, R.; Casey, A. R.; Randich, S.; Magrini, L.; San, Roman I.; Munoz, C.; Cohen, R. E.; Mauro, F.; Bragaglia, A.; Donati, P.; Tautvaisiene, G.; Drazdauskas, A.; Zenoviene, R.; Snaith, O.; Sousa, S.; Adibekyan, V.; Costado, M. T.; Blanco-Cuaresma, S.; Jimenez-Esteban, F.; Carraro, G.; Zwitter, T.; Francois, P.; Jofre, P.; Sordo, R.; Gilmore, G.; Flaccomio, E.; Koposov, S.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.; Bayo, A.; Damiani, F.; Franciosini, E.; Hourihane, A.; Lardo, C.; Lewis, J.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sacco, G.; Worley, C. C.; Zaggia, S.
2016-11-01
The dwarf stars in NGC 6802 observed by GIRAFFE spectrograph are separated into four tables: 1. cluster members in the lower main sequence; 2. cluster members in the upper main sequence; 3. non-member dwarfs in the lower main sequence; 4. non-member dwarfs in the upper main sequence. The star coordinates, V band magnitude, V-I color, and radial velocity are given. (4 data files).
Carter, Mark W.; Merschat, Arthur J.
2014-01-01
The contact between eastern Blue Ridge stratified rocks above Mesoproterozoic basement rocks is mostly faulted (Gossan Lead and Red Valley). The Callaway fault juxtaposes Ashe and Lynchburg rocks above Wills Ridge Formation. Alligator Back Formation rocks overlie Ashe and Lynchburg rocks along the Rock Castle Creek fault, which juxtaposes rocks of different metamorphism. The fault separates major structural domains: rocks with one penetrative foliation in the footwall, and pin-striped recrystallized compositional layering, superposed penetrative foliations, and cleavage characterize the hanging wall. These relationships are ambiguous along strike to the southwest, where the Ashe and Alligator Back formations are recrystallized at higher metamorphic grades.
Blue large-amplitude pulsators as a new class of variable stars
NASA Astrophysics Data System (ADS)
Pietrukowicz, Paweł; Dziembowski, Wojciech A.; Latour, Marilyn; Angeloni, Rodolfo; Poleski, Radosław; di Mille, Francesco; Soszyński, Igor; Udalski, Andrzej; Szymański, Michał K.; Wyrzykowski, Łukasz; Kozłowski, Szymon; Skowron, Jan; Skowron, Dorota; Mróz, Przemek; Pawlak, Michał; Ulaczyk, Krzysztof
2017-08-01
Regular intrinsic brightness variations observed in many stars are caused by pulsations. These pulsations provide information on the global and structural parameters of the star. The pulsation periods range from seconds to years, depending on the compactness of the star and properties of the matter that forms its outer layers. Here, we report the discovery of more than a dozen previously unknown short-period variable stars: blue large-amplitude pulsators. These objects show very regular brightness variations with periods in the range of 20-40 min and amplitudes of 0.2-0.4 mag in the optical passbands. The phased light curves have a characteristic sawtooth shape, similar to the shape of classical Cepheids and RR Lyrae-type stars pulsating in the fundamental mode. The objects are significantly bluer than main-sequence stars observed in the same fields, which indicates that all of them are hot stars. Follow-up spectroscopy confirms a high surface temperature of about 30,000 K. Temperature and colour changes over the cycle prove the pulsational nature of the variables. However, large-amplitude pulsations at such short periods are not observed in any known type of stars, including hot objects. Long-term photometric observations show that the variable stars are very stable over time. Derived rates of period change are of the order of 10-7 per year and, in most cases, they are positive. According to pulsation theory, such large-amplitude oscillations may occur in evolved low-mass stars that have inflated helium-enriched envelopes. The evolutionary path that could lead to such stellar configurations remains unknown.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Antonini, Fabio; Chatterjee, Sourav; Rodriguez, Carl L.
Hierarchical triple-star systems are expected to form frequently via close binary–binary encounters in the dense cores of globular clusters (GCs). In a sufficiently inclined triple, gravitational interactions between the inner and outer binary can cause large-amplitude oscillations in the eccentricity of the inner orbit (“Lidov–Kozai (LK) cycles”), which can lead to a collision and merger of the two inner components. In this paper we use Monte Carlo models of dense star clusters to identify all triple systems formed dynamically and we compute their evolution using a highly accurate three-body integrator which incorporates relativistic and tidal effects. We find that amore » large fraction of these triples evolve through a non-secular dynamical phase which can drive the inner binary to higher eccentricities than predicted by the standard secular perturbation theory (even including octupole-order terms). We place constraints on the importance of LK-induced mergers for producing: (i) gravitational wave sources detectable by Advanced LIGO (aLIGO), for triples with an inner pair of stellar black holes (BHs); and (ii) blue straggler stars, for triples with main-sequence-star components. We find a realistic aLIGO detection rate of BH mergers due to the LK mechanism of ∼1 yr{sup −1}, with about 20% of these having a finite eccentricity when they first chirp into the aLIGO frequency band. While rare, these events are likely to dominate among eccentric compact object inspirals that are potentially detectable by aLIGO. For blue stragglers, we find that the LK mechanism can contribute up to ∼10% of their total numbers in GCs.« less
Collier, Jackie L; Fitzgerald, Sean P; Hice, Lyndie A; Frisk, Michael G; McElroy, Anne E
2014-01-01
Winter flounder (Pseudopleuronectes americanus) once supported robust commercial and recreational fisheries in the New York (USA) region, but since the 1990s populations have been in decline. Available data show that settlement of young-of-the-year winter flounder has not declined as sharply as adult abundance, suggesting that juveniles are experiencing higher mortality following settlement. The recent increase of blue crab (Callinectes sapidus) abundance in the New York region raises the possibility that new sources of predation may be contributing to juvenile winter flounder mortality. To investigate this possibility we developed and validated a method to specifically detect winter flounder mitochondrial control region DNA sequences in the gut contents of blue crabs. A survey of 55 crabs collected from Shinnecock Bay (along the south shore of Long Island, New York) in July, August, and September of 2011 showed that 12 of 42 blue crabs (28.6%) from which PCR-amplifiable DNA was recovered had consumed winter flounder in the wild, empirically supporting the trophic link between these species that has been widely speculated to exist. This technique overcomes difficulties with visual identification of the often unrecognizable gut contents of decapod crustaceans, and modifications of this approach offer valuable tools to more broadly address their feeding habits on a wide variety of species.
Epistatic interactions influence terrestrial–marine functional shifts in cetacean rhodopsin
2017-01-01
Like many aquatic vertebrates, whales have blue-shifting spectral tuning substitutions in the dim-light visual pigment, rhodopsin, that are thought to increase photosensitivity in underwater environments. We have discovered that known spectral tuning substitutions also have surprising epistatic effects on another function of rhodopsin, the kinetic rates associated with light-activated intermediates. By using absorbance spectroscopy and fluorescence-based retinal release assays on heterologously expressed rhodopsin, we assessed both spectral and kinetic differences between cetaceans (killer whale) and terrestrial outgroups (hippo, bovine). Mutation experiments revealed that killer whale rhodopsin is unusually resilient to pleiotropic effects on retinal release from key blue-shifting substitutions (D83N and A292S), largely due to a surprisingly specific epistatic interaction between D83N and the background residue, S299. Ancestral sequence reconstruction indicated that S299 is an ancestral residue that predates the evolution of blue-shifting substitutions at the origins of Cetacea. Based on these results, we hypothesize that intramolecular epistasis helped to conserve rhodopsin's kinetic properties while enabling blue-shifting spectral tuning substitutions as cetaceans adapted to aquatic environments. Trade-offs between different aspects of molecular function are rarely considered in protein evolution, but in cetacean and other vertebrate rhodopsins, may underlie multiple evolutionary scenarios for the selection of specific amino acid substitutions. PMID:28250185
NASA Astrophysics Data System (ADS)
Rakleviciene, D.; Svegzdiene, D.; Tamulaitis, G.; Zukauskas, A.
2005-08-01
The growth rate and orientation of cress seedlings in response to the direction of illumination under clino- rotation were investigated at the initial stage of intensive hypocotyl elongation. Roots and hypocotyls growing in normal gravity conditions (1 g) and under clino-rotation at 3 rpm were illuminated with red (660 nm) or blue (450 nm) light from light-emitting diodes (LEDs). Unidirectional illumination in the direction opposite to the gravity vector promoted the growth rate of roots. Inhibition of gravitropism by clino-rotation reduced the growth of roots and stimulated the elongation of hypocotyls in both red and blue light. Illumination of roots invoked changes in the formation of gravisensing cells in the columella. Illumination under clino-rotation stimulated root statocyte growth and increased the number of amyloplasts in cells of the 3rd-6th columella rows. Also, an increase in the columella cell area, mainly caused by cell elongation in blue light and by enhanced radial growth in red light, was observed.
Rohs, Remo; Sklenar, Heinz
2004-04-01
The results presented in this paper on methylene blue (MB) binding to DNA with AT alternating base sequence complement the data obtained in two former modeling studies of MB binding to GC alternating DNA. In the light of the large amount of experimental data for both systems, this theoretical study is focused on a detailed energetic analysis and comparison in order to understand their different behavior. Since experimental high-resolution structures of the complexes are not available, the analysis is based on energy minimized structural models of the complexes in different binding modes. For both sequences, four different intercalation structures and two models for MB binding in the minor and major groove have been proposed. Solvent electrostatic effects were included in the energetic analysis by using electrostatic continuum theory, and the dependence of MB binding on salt concentration was investigated by solving the non-linear Poisson-Boltzmann equation. We find that the relative stability of the different complexes is similar for the two sequences, in agreement with the interpretation of spectroscopic data. Subtle differences, however, are seen in energy decompositions and can be attributed to the change from symmetric 5'-YpR-3' intercalation to minor groove binding with increasing salt concentration, which is experimentally observed for the AT sequence at lower salt concentration than for the GC sequence. According to our results, this difference is due to the significantly lower non-electrostatic energy for the minor groove complex with AT alternating DNA, whereas the slightly lower binding energy to this sequence is caused by a higher deformation energy of DNA. The energetic data are in agreement with the conclusions derived from different spectroscopic studies and can also be structurally interpreted on the basis of the modeled complexes. The simple static modeling technique and the neglect of entropy terms and of non-electrostatic solute-solvent interactions, which are assumed to be nearly constant for the compared complexes of MB with DNA, seem to be justified by the results.
Meng, Yingying; Li, Hongyu; Wang, Qin; Liu, Bin; Lin, Chentao
2013-01-01
Cryptochromes are blue light receptors that regulate light responses in plants, including various crops. The molecular mechanism of plant cryptochromes has been extensively investigated in Arabidopsis thaliana, but it has not been reported in any crop species. Here, we report a study of the mechanism of soybean (Glycine max) cryptochrome2 (CRY2a). We found that CRY2a regulates leaf senescence, which is a life history trait regulated by light and photoperiods via previously unknown mechanisms. We show that CRY2a undergoes blue light–dependent interaction with the soybean basic helix-loop-helix transcription activator CIB1 (for cryptochrome-interacting bHLH1) that specifically interacts with the E-box (CANNTG) DNA sequences. Analyses of transgenic soybean plants expressing an elevated or reduced level of the CRY2a or CIB1 demonstrate that CIB1 promotes leaf senescence, whereas CRY2a suppresses leaf senescence. Results of the gene expression and molecular interaction analyses support the hypothesis that CIB1 activates transcription of senescence-associated genes, such as WRKY DNA BINDING PROTEIN53b (WRKY53b), and leaf senescence. CIB1 interacts with the E-box–containing promoter sequences of the WRKY53b chromatin, whereas photoexcited CRY2a interacts with CIB1 to inhibit its DNA binding activity. These findings argue that CIB-dependent transcriptional regulation is an evolutionarily conserved CRY-signaling mechanism in plants, and this mechanism is opted in evolution to mediate light regulation of different aspects of plant development in different plant species. PMID:24272488
NASA Technical Reports Server (NTRS)
McManus, J. D.; Brune, D. C.; Han, J.; Sanders-Loehr, J.; Meyer, T. E.; Cusanovich, M. A.; Tollin, G.; Blankenship, R. E.
1992-01-01
Three small blue copper proteins designated auracyanin A, auracyanin B-1, and auracyanin B-2 have been isolated from the thermophilic green gliding photosynthetic bacterium Chloroflexus aurantiacus. All three auracyanins are peripheral membrane proteins. Auracyanin A was described previously (Trost, J. T., McManus, J. D., Freeman, J. C., Ramakrishna, B. L., and Blankenship, R. E. (1988) Biochemistry 27, 7858-7863) and is not glycosylated. The two B forms are glycoproteins and have almost identical properties to each other, but are distinct from the A form. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis apparent monomer molecular masses are 14 (A), 18 (B-2), and 22 (B-1) kDa. The amino acid sequences of the B forms are presented. All three proteins have similar absorbance, circular dichroism, and resonance Raman spectra, but the electron spin resonance signals are quite different. Laser flash photolysis kinetic analysis of the reactions of the three forms of auracyanin with lumiflavin and flavin mononucleotide semiquinones indicates that the site of electron transfer is negatively charged and has an accessibility similar to that found in other blue copper proteins. Copper analysis indicates that all three proteins contain 1 mol of copper per mol of protein. All three auracyanins exhibit a midpoint redox potential of +240 mV. Light-induced absorbance changes and electron spin resonance signals suggest that auracyanin A may play a role in photosynthetic electron transfer. Kinetic data indicate that all three proteins can donate electrons to cytochrome c-554, the electron donor to the photosynthetic reaction center.
Phosphorous Diffuser Diverged Blue Laser Diode for Indoor Lighting and Communication
Chi, Yu-Chieh; Hsieh, Dan-Hua; Lin, Chung-Yu; Chen, Hsiang-Yu; Huang, Chia-Yen; He, Jr-Hau; Ooi, Boon; DenBaars, Steven P.; Nakamura, Shuji; Kuo, Hao-Chung; Lin, Gong-Ru
2015-01-01
An advanced light-fidelity (Li-Fi) system based on the blue Gallium nitride (GaN) laser diode (LD) with a compact white-light phosphorous diffuser is demonstrated for fusing the indoor white-lighting and visible light communication (VLC). The phosphorous diffuser adhered blue GaN LD broadens luminescent spectrum and diverges beam spot to provide ample functionality including the completeness of Li-Fi feature and the quality of white-lighting. The phosphorous diffuser diverged white-light spot covers a radiant angle up to 120o with CIE coordinates of (0.34, 0.37). On the other hand, the degradation on throughput frequency response of the blue LD is mainly attributed to the self-feedback caused by the reflection from the phosphor-air interface. It represents the current state-of-the-art performance on carrying 5.2-Gbit/s orthogonal frequency-division multiplexed 16-quadrature-amplitude modulation (16-QAM OFDM) data with a bit error rate (BER) of 3.1 × 10−3 over a 60-cm free-space link. This work aims to explore the plausibility of the phosphorous diffuser diverged blue GaN LD for future hybrid white-lighting and VLC systems. PMID:26687289
Phosphorous Diffuser Diverged Blue Laser Diode for Indoor Lighting and Communication
NASA Astrophysics Data System (ADS)
Chi, Yu-Chieh; Hsieh, Dan-Hua; Lin, Chung-Yu; Chen, Hsiang-Yu; Huang, Chia-Yen; He-Hau, Jr.; Ooi, Boon; Denbaars, Steven P.; Nakamura, Shuji; Kuo, Hao-Chung; Lin, Gong-Ru
2015-12-01
An advanced light-fidelity (Li-Fi) system based on the blue Gallium nitride (GaN) laser diode (LD) with a compact white-light phosphorous diffuser is demonstrated for fusing the indoor white-lighting and visible light communication (VLC). The phosphorous diffuser adhered blue GaN LD broadens luminescent spectrum and diverges beam spot to provide ample functionality including the completeness of Li-Fi feature and the quality of white-lighting. The phosphorous diffuser diverged white-light spot covers a radiant angle up to 120o with CIE coordinates of (0.34, 0.37). On the other hand, the degradation on throughput frequency response of the blue LD is mainly attributed to the self-feedback caused by the reflection from the phosphor-air interface. It represents the current state-of-the-art performance on carrying 5.2-Gbit/s orthogonal frequency-division multiplexed 16-quadrature-amplitude modulation (16-QAM OFDM) data with a bit error rate (BER) of 3.1 × 10-3 over a 60-cm free-space link. This work aims to explore the plausibility of the phosphorous diffuser diverged blue GaN LD for future hybrid white-lighting and VLC systems.
Jeffet, U; Nasrallah, R; Sterer, N
2016-11-21
Oral malodour is considered to be caused mainly by the production of volatile sulfide compounds (VSC) by anaerobic Gram-negative oral bacteria. Previous study showed that these bacteria were susceptible to blue light (wavelengths of 400-500 nm). In the present study, we tested the effect of blue light in the presence of red dyes on malodour production in an experimental oral biofilm. Biofilms were exposed to a plasma-arc light source for 30, 60, and 120 s (i.e. fluences of 41, 82, and 164 J cm -2 , respectively) with the addition of erythrosine, natural red and rose bengal (0.01, 0.1 and 1% w/v). Following light exposure biofilm samples were examined for malodour production (Odour judge), VSC production (Halimeter ™ ), VSC producing bacteria quantification using microscopy sulfide assay (MSA) and reactive oxygen species (ROS) production. Results showed that the exposure of experimental oral biofilm to blue light in the presence of rose bengal caused an increased reduction in VSC and malodour production concomitant with an increase in ROS production. These results suggest that rose bengal might be effective as a blue light photosensitizer against VSC producing bacteria.
Escobar-Sánchez, Ofelia; Galván-Magaña, Felipe; Rosíles-Martínez, René
2011-12-01
The aim of this study was to determine the biomagnification of mercury through the principal prey of the blue shark, Prionace glauca, off the western coast of Baja California Sur, Mexico, as well as the relationship between mercury and selenium in blue sharks. High levels of mercury were found in shark muscle tissues (1.39 ± 1.58 μg/g wet weight); these values are above the allowed 1.0 μg/g for human consumption. The mercury to selenium molar ratio was 1:0.2. We found a low correlation between mercury bioaccumulation and shark size. Juveniles have lower concentrations of mercury than adults. Regarding the analyzed prey, the main prey of the blue shark, pelagic red crab, Pleuroncodes planipes, bioaccumulated 0.04 ± 0.01 μg/g Hg wet weight, but the prey with higher bioaccumulation was the bullet fish Auxis spp. (0.20 ± 0.02 μg/g wet weight). In terms of volume, the red crab P. planipes can be the prey that provides high levels of mercury to the blue shark.
Porting Ordinary Applications to Blue Gene/Q Supercomputers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Maheshwari, Ketan C.; Wozniak, Justin M.; Armstrong, Timothy
2015-08-31
Efficiently porting ordinary applications to Blue Gene/Q supercomputers is a significant challenge. Codes are often originally developed without considering advanced architectures and related tool chains. Science needs frequently lead users to want to run large numbers of relatively small jobs (often called many-task computing, an ensemble, or a workflow), which can conflict with supercomputer configurations. In this paper, we discuss techniques developed to execute ordinary applications over leadership class supercomputers. We use the high-performance Swift parallel scripting framework and build two workflow execution techniques-sub-jobs and main-wrap. The sub-jobs technique, built on top of the IBM Blue Gene/Q resource manager Cobalt'smore » sub-block jobs, lets users submit multiple, independent, repeated smaller jobs within a single larger resource block. The main-wrap technique is a scheme that enables C/C++ programs to be defined as functions that are wrapped by a high-performance Swift wrapper and that are invoked as a Swift script. We discuss the needs, benefits, technicalities, and current limitations of these techniques. We further discuss the real-world science enabled by these techniques and the results obtained.« less
Contrasts in Blue: Life on the Caribbean Coral Reef and the Rocky Coast of Maine.
ERIC Educational Resources Information Center
Art to Zoo: Teaching with the Power of Objects, 1996
1996-01-01
Ecosystem contrasts between the Caribbean Coral Reef and the Rocky coast of Maine are the focus of this instructional resource. The publication, issued four times a year, explores single topics through an interdisciplinary, multicultural approach. The activities presented in this issue encourage students to consider the role of temperature,…
Hydrogen production by a thermophilic blue-green alga Mastigocladus laminosus
NASA Astrophysics Data System (ADS)
Miura, Y.; Yokoyama, H.; Miyamoto, K.; Okazaki, M.; Komemushi, S.
Light-driven hydrogen evolution by a thermophilic blue-green alga, Mastigocladus laminosus, was demonstrated and characterized under nitrogen-starved conditions. Air-grown cultures of this alga evolved hydrogen under Ar/CO2 at rates up to 2.2 ml/mg chl/hr. The optimum temperature and pH for the hydrogen evolution were 44-49 C and pH 7.0-7.5, respectively. Evolution in light was depressed by N2 gas and inhibited by salicylaldoxime or 2,4-dinitrophenol, indicating that nitrogenase was mainly responsible for the hydrogen evolution. The evolution rate was improved by adding carbon monoxide and acetylene to the gas phase of Ar/CO2. In addition, photobiological production of hydrogen (biophotolysis) by various blue-green algae is briefly reviewed and discussed.
Graham, Jennifer L.; Stone, Mandy L.; Rasmussen, Teresa J.; Poulton, Barry C.
2010-01-01
The Johnson County Blue River Main Wastewater Treatment Facility discharges into the upper Blue River near the border between Johnson County, Kansas and Jackson County, Missouri. During 2005 through 2007 the wastewater treatment facility underwent upgrades to increase capacity and include biological nutrient removal. The effects of wastewater effluent on environmental and biological conditions of the upper Blue River were assessed by comparing an upstream site to two sites located downstream from the wastewater treatment facility. Environmental conditions were evaluated using previously and newly collected discrete and continuous data, and were compared with an assessment of biological community composition and ecosystem function along the upstream-downstream gradient. This evaluation is useful for understanding the potential effects of wastewater effluent on water quality, biological community structure, and ecosystem function. In addition, this information can be used to help achieve National Pollution Discharge Elimination System (NPDES) wastewater effluent permit requirements after additional studies are conducted. The effects of wastewater effluent on the water-quality conditions of the upper Blue River were most evident during below-normal and normal streamflows (about 75 percent of the time), when wastewater effluent contributed more than 20 percent to total streamflow. The largest difference in water-quality conditions between the upstream and downstream sites was in nutrient concentrations. Total and inorganic nutrient concentrations at the downstream sites during below-normal and normal streamflows were 4 to 15 times larger than at the upstream site, even after upgrades to the wastewater treatment facility were completed. However, total nitrogen concentrations decreased in wastewater effluent and at the downstream site following wastewater treatment facility upgrades. Similar decreases in total phosphorus were not observed, likely because the biological phosphorus removal process was not optimized until after the study was completed. Total nitrogen and phosphorus from the wastewater treatment facility contributed a relatively small percentage (14 to 15 percent) to the annual nutrient load in the upper Blue River, but contributed substantially (as much as 75 percent) to monthly loads during seasonal low-flows in winter and summer. During 2007 and 2008, annual discharge from the wastewater treatment facility was about one-half maximum capacity, and estimated potential maximum annual loads were 1.6 to 2.4 times greater than annual loads before capacity upgrades. Even when target nutrient concentrations are met, annual nutrient loads will increase when the wastewater treatment facility is operated at full capacity. Regardless of changes in annual nutrient loads, the reduction of nutrient concentrations in the Blue River Main wastewater effluent will help prevent further degradation of the upper Blue River. The Blue River Main Wastewater Treatment Facility wastewater effluent caused changes in concentrations of several water-quality constituents that may affect biological community structure and function including larger concentrations of bioavailable nutrients (nitrate and orthophosphorus) and smaller turbidities. Streambed-sediment conditions were similar along the upstream-downstream gradient and measured constituents did not exceed probable effect concentrations. Habitat conditions declined along the upstream-downstream gradient, largely because of decreased canopy cover and riparian buffer width and increased riffle-substrate fouling. Algal biomass, primary production, and the abundance of nutrient-tolerant diatoms substantially increased downstream from the wastewater treatment facility. Likewise, the abundance of intolerant macroinvertebrate taxa and Kansas Department of Health and Environment aquatic-life-support scores, derived from macroinvertebrate data, significantly decreased downstream from the wastewater
Did A Planet Survive A Post-Main Sequence Evolutionary Event?
NASA Astrophysics Data System (ADS)
Sorber, Rebecca; Jang-Condell, Hannah; Zimmerman, Mara
2018-06-01
The GL86 is star system approximately 10 pc away with a main sequence K- type ~ 0.77 M⊙ star (GL 86A) with a white dwarf ~0.49 M⊙ companion (GL86 B). The system has a ~ 18.4 AU semi-major axis, an orbital period of ~353 yrs, and an eccentricity of ~ 0.39. A 4.5 MJ planet orbits the main sequence star with a semi-major axis of 0.113 AU, an orbital period of 15.76 days, in a near circular orbit with an eccentricity of 0.046. If we assume that this planet was formed during the time when the white dwarf was a main sequence star, it would be difficult for the planet to have remained in a stable orbit during the post-main sequence evolution of GL86 B. The post-main sequence evolution with planet survival will be examined by modeling using the program Mercury (Chambers 1999). Using the model, we examine the origins of the planet: whether it formed before or after the post-main sequence evolution of GL86B. The modeling will give us insight into the dynamical evolution of, not only, the binary star system, but also the planet’s life cycle.
Yang, Xi-Juan; Dang, Bin; Fan, Ming-Tao
2018-04-11
In this study, the polyphenols composition and antioxidant properties of 12 blue highland barley varieties planted on the Qinghai-Tibet Plateau area were measured. The contents of the free, bound and total phenolic acids varied between 166.20-237.60, 170.10-240.75 and 336.29-453.94 mg of gallic acid equivalents per 100 g of dry weight (DW) blue highland barley grains, while the free and bound phenolic acids accounted for 50.09% and 49.91% of the total phenolic acids, respectively. The contents of the free, bound and total flavones varied among 20.61-25.59, 14.91-22.38 and 37.91-47.98 mg of catechin equivalents per 100 g of dry weight (DW) of blue highland barley grains, while the free and bound flavones accounted for 55.90% and 44.10% of the total flavones, respectively. The prominent phenolic compounds in the blue hulless barley grains were gallic acid, benzoic acid, syringic acid, 4-coumaric acid, naringenin, hesperidin, rutin, (+)-catechin and quercetin. Among these, protocatechuic acid, chlorogenic acid and (+)-catechin were the major phenolic compounds in the free phenolics extract. The most abundant bound phenolics were gallic acid, benzoic acid, syringic acid, 4-coumaric acid, benzoic acid, dimethoxybenzoic acid, naringenin, hesperidin, quercetin and rutin. The average contribution of the bound phenolic extract to the DPPH • free radical scavenging capacity was higher than 86%, that of free phenolic extract to the ABTS •+ free radical scavenging capacity was higher than 79%, and that of free phenolic (53%) to the FRAP antioxidant activity was equivalent to that of the bound phenol extract (47%). In addition, the planting environment exerts a very important influence on the polyphenol composition, content and antioxidant activity of blue highland barley. The correlation analysis showed that 2,4-hydroxybenzoic acid and protocatechuic acid were the main contributors to the DPPH • and ABTS •+ free radical scavenging capacity in the free phenolic extract, while chlorogenic acid, vanillic acid, ferulic acid and quercetin were the main contributors to the free radical scavenging capacity in the bound phenol extract. The study results show that the blue highland barley grains have rich phenolic compounds and high antioxidant activity, as well as significant varietal differences. The free and bound phenolic extracts in the blue hulless barley grains have an equivalent proportion in the total phenol, and co-exist in two forms. They can be used as a potential valuable source of natural antioxidants, and can aid in enhancing the development and daily consumption of foods relating to blue highland barley.
NASA Astrophysics Data System (ADS)
Jin, Shan; Zhou, Liangjun; Gu, Zhanjun; Tian, Gan; Yan, Liang; Ren, Wenlu; Yin, Wenyan; Liu, Xiaodong; Zhang, Xiao; Hu, Zhongbo; Zhao, Yuliang
2013-11-01
The utilization of up-conversion nanoparticles (UCNPs) for photodynamic therapy (PDT) has gained significant interest due to their unique ability to convert near infrared light to UV/visible light. Previous work mainly focused on the fabrication of green and red emitting UCNPs to load photosensitizers (PSs) for PDT. In this work, we firstly developed a new multifunctional nanoplatform combining blue-emitting UCNPs with blue-light excited PS (hypocrellin A, HA) as a NIR photosensitizing nanoplatform for PDT of cancer cells. Tween 20 coated NaYbF4:Tm, Gd@NaGdF4 UCNPs (Tween 20-UCNPs) with strong blue up-conversion luminescence and good water dispersibility were prepared for use as PS carriers. The blue emission band matched well with the efficient absorption band of HA, thereby facilitating the resonance energy transfer from UCNPs to HA and then activating HA to produce singlet oxygen (1O2). The in vitro study showed that these Tween 20-UCNPs@HA complexes could efficiently produce 1O2 to kill cancer cells under 980 nm NIR excitation. Moreover, these Gd3+ and Yb3+ containing nanoparticles also exhibited positive contrast effects in both T1 weighted magnetic resonance imaging (MRI) and computed tomography (CT) imaging, making them become a multifunctional platform for simultaneous PDT and bio-imaging.The utilization of up-conversion nanoparticles (UCNPs) for photodynamic therapy (PDT) has gained significant interest due to their unique ability to convert near infrared light to UV/visible light. Previous work mainly focused on the fabrication of green and red emitting UCNPs to load photosensitizers (PSs) for PDT. In this work, we firstly developed a new multifunctional nanoplatform combining blue-emitting UCNPs with blue-light excited PS (hypocrellin A, HA) as a NIR photosensitizing nanoplatform for PDT of cancer cells. Tween 20 coated NaYbF4:Tm, Gd@NaGdF4 UCNPs (Tween 20-UCNPs) with strong blue up-conversion luminescence and good water dispersibility were prepared for use as PS carriers. The blue emission band matched well with the efficient absorption band of HA, thereby facilitating the resonance energy transfer from UCNPs to HA and then activating HA to produce singlet oxygen (1O2). The in vitro study showed that these Tween 20-UCNPs@HA complexes could efficiently produce 1O2 to kill cancer cells under 980 nm NIR excitation. Moreover, these Gd3+ and Yb3+ containing nanoparticles also exhibited positive contrast effects in both T1 weighted magnetic resonance imaging (MRI) and computed tomography (CT) imaging, making them become a multifunctional platform for simultaneous PDT and bio-imaging. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03515h
75 FR 78617 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-16
...-1085 Blue Hill Creek Approximately 1,546 feet +462 City of Abbeville. downstream of South Main Street... 29620. Edgefield County, South Carolina, and Incorporated Areas Docket No.: FEMA-B-1085 Stevens Creek...
700 W blue fiber-coupled diode-laser emitting at 450 nm
NASA Astrophysics Data System (ADS)
Balck, A.; Baumann, M.; Malchus, J.; Chacko, R. V.; Marfels, S.; Witte, U.; Dinakaran, D.; Ocylok, S.; Weinbach, M.; Bachert, C.; Kösters, A.; Krause, V.; König, H.; Lell, A.; Stojetz, B.; Löffler, A.; Strauss, U.
2018-02-01
A high-power blue laser source was long-awaited for processing materials with low absorption in the near infrared (NIR) spectral range like copper or gold. Due to the huge progress of GaN-based semiconductors, the performance of blue diode-lasers has made a major step forward recently. With the availability of unprecedented power levels at cw-operating blue diode-lasers emitting at 450 nm, it was possible to set up a high-power diode-laser in the blue spectral range to address these conventional laser applications and probably beyond that to establish completely new utilizations for lasers. Within the scope of the research project "BlauLas", funded within the German photonic initiative "EFFILAS" [8] by the German Federal Ministry of Education and Research (BMBF), Laserline in cooperation with OSRAM aims to realize a cw fiber-coupled diode-laser exceeding 1 kW blue laser power. In this paper the conceptual design and experimental results of a 700 W blue fiber-coupled diode-laser are presented. Initially a close look had to be taken on the mounting techniques of the semiconductors to serve the requirements of the GaN laser diodes. Early samples were used for extensive long term tests to investigate degradation processes. With first functional laser-modules we set up fiber-coupled laser-systems for further testing. Besides adaption of well-known optical concepts a main task within the development of the laser system was the selection and examination of suitable materials and assembling in order to minimize degradation and reach adequate lifetimes. We realized R&D blue lasersystems with lifetimes above 5,000 h, which enable first application experiments on processing of various materials as well as experiments on conversion to white-light.
Koo, Min Seok; Cho, Kangwoo; Yoon, Jeyong; Choi, Wonyong
2017-06-06
Vertically aligned TiO 2 nanotube arrays (TNTs) were prepared by electrochemical anodization, and then cathodically polarized with dark blue coloration for the dual-functional photoelectrochemical water treatment of organic substrates degradation and accompanying H 2 generation. The resulting Blue-TNTs (inner diameter: ∼40 nm; length: ∼9 μm) showed negligible shift in X-ray diffraction pattern compared with the intact TNTs, but the X-ray photoelectron spectra indicated a partial reduction of Ti 4+ to Ti 3+ on the surface. The electrochemical analyses of Blue-TNTs revealed a marked enhancement in donor density and electrical conductivity by orders of magnitude. Degradations of test organic substrates on Blue-TNTs were compared with the intact TNTs in electrochemical (EC), photocatalytic (PC), and photoelectrochemical (PEC) conditions (potential bias: 1.64 V NHE ; λ > 320 nm). The degradation of 4-chlorophenol was greatly enhanced on Blue-TNTs particularly in PEC condition, whereas the PC activities of the Blue- and intact TNTs were similar. The potential bias of 1.64 V NHE did not induce any noticeable activity in EC condition. Similar trends were observed for the degradation of humic acid and fulvic acid, where main working oxidants were found to be the surface hydroxyl radical as confirmed by hydroxyl radical probe and scavenger tests. H 2 generation coupled with the organic degradation was observed only in PEC condition, where the H 2 generation rate with Blue-TNTs was more than doubled from that of intact TNTs. Such superior PEC activity was not observed when a common TiO 2 nanoparticle film was used as a photoanode. The enhanced electric conductivity of Blue-TNTs coupled with a proper band bending in PEC configuration seemed to induce a highly synergic enhancement.
Aryal, Achyut; Coogan, Sean C P; Ji, Weihong; Rothman, Jessica M; Raubenheimer, David
2015-09-01
Food resources are often critical regulating factors affecting individual fitness and population densities. In the Himalayan Mountains, Bharal "blue sheep" (Pseudois nayaur) are the main food resource for the endangered snow leopard (Panthera uncia), as well as being preyed upon by other predators. Blue sheep, however, may face a number of challenges including food resource competition with other wild and domestic ungulates, and hunting pressure. Here, we characterized the diet of blue sheep in the Annapurna Conservation Area (ACA) of Nepal and conducted proximate nutritional analysis on a limited number of plants identified as foods. Furthermore, we investigated the macronutrient and fiber balance of these plants using nutritional geometry which is a state-space approach to modeling multidimensional and interactive nutritional aspects of foraging. A total of 19 plant species/genera were identified in blue sheep pellets using microhistological analysis. On average, across seasons and regions of the study area, the two most frequently occurring plants in pellets were graminoids: Kobressia sp. and Carex spp. The macronutrient balance of Kobresia sp. was relatively high in carbohydrate and low in protein, while other plants in the diet were generally higher in protein and lipid content. Analysis of fiber balance showed that the two most consumed plants of blue sheep (i.e., Kobresia spp. and Carex spp.) contained the highest concentration of hemicellulose, which is likely digestible by blue sheep. The hemicellulose and lignin balance of plants ranged relatively widely, yet their cellulose contents showed less variation. Foraging by blue sheep may therefore be a balance between consuming highly digestible high-carbohydrate plants and plants less-digestible but higher in protein and/or lipid.
Saturn's Hexagon as Summer Solstice Approaches
2017-05-24
These natural color views from NASA's Cassini spacecraft compare the appearance of Saturn's north-polar region in June 2013 and April 2017. In both views, Saturn's polar hexagon dominates the scene. The comparison shows how clearly the color of the region changed in the interval between the two views, which represents the latter half of Saturn's northern hemisphere spring. In 2013, the entire interior of the hexagon appeared blue. By 2017, most of the hexagon's interior was covered in yellowish haze, and only the center of the polar vortex retained the blue color. The seasonal arrival of the sun's ultraviolet light triggers the formation of photochemical aerosols, leading to haze formation. The general yellowing of the polar region is believed to be caused by smog particles produced by increasing solar radiation shining on the polar region as Saturn approached the northern summer solstice on May 24, 2017. Scientists are considering several ideas to explain why the center of the polar vortex remains blue while the rest of the polar region has turned yellow. One idea is that, because the atmosphere in the vortex's interior is the last place in the northern hemisphere to be exposed to spring and summer sunlight, smog particles have not yet changed the color of the region. A second explanation hypothesizes that the polar vortex may have an internal circulation similar to hurricanes on Earth. If the Saturnian polar vortex indeed has an analogous structure to terrestrial hurricanes, the circulation should be downward in the eye of the vortex. The downward circulation should keep the atmosphere clear of the photochemical smog particles, and may explain the blue color. Images captured with Cassini's wide-angle camera using red, green and blue spectral filters were combined to create these natural-color views. The 2013 view (left in the combined view), was captured on June 25, 2013, when the spacecraft was about 430,000 miles (700,000 kilometers) away from Saturn. The original versions of these images, as sent by the spacecraft, have a size of 512 by 512 pixels and an image scale of about 52 miles (80 kilometers) per pixel; the images have been mapped in polar stereographic projection to the resolution of approximately 16 miles (25 kilometers) per pixel. The second and third frames in the animation were taken approximately 130 and 260 minutes after the first image. The 2017 sequence (right in the combined view) was captured on April 25, 2017, just before Cassini made its first dive between Saturn and its rings. During the imaging sequence, the spacecraft's distance from the center of the planet changed from 450,000 miles (725,000 kilometers) to 143,000 miles (230,000 kilometers). The original versions of these images, as sent by the spacecraft, have a size of 512 by 512 pixels. The resolution of the original images changed from about 52 miles (80 kilometers) per pixel at the beginning to about 9 miles (14 kilometers) per pixel at the end. The images have been mapped in polar stereographic projection to the resolution of approximately 16 miles (25 kilometers) per pixel. The average interval between the frames in the movie sequence is 230 minutes. Corresponding animated movie sequences are available at https://photojournal.jpl.nasa.gov/catalog/PIA21611 https://photojournal.jpl.nasa.gov/catalog/PIA21611
NASA Astrophysics Data System (ADS)
Kilany, Mona
2017-11-01
The potentially deleterious effects of methylene blue (MB) on human health drove the interest in its removal promptly. Bioremediation is an effective and eco friendly for removing MB. Soil bacteria were isolated and examined for their potential to remove MB. The most potent bacterial candidate was characterized and identified using 16S rRNA sequence technique. The evolutionary history of the isolate was conducted by maximum likelihood method. Some physiochemical parameters were optimized for maximum decolorization. Decolorization mechanism and microbial toxicity study of MB (100 mg/l) and by-products were investigated. Participation of heat killed bacteria in color adsorption have been investigated too. The bacterial isolate was identified as Stenotrophomonas maltophilia strain Kilany_MB 16S ribosomal RNA gene with 99% sequence similarity. The sequence was submitted to NCBI (Accession number = KU533726). Phylogeny depicted the phylogenetic relationships between 16S ribosomal RNA gene, partial sequence (1442 bp), of the isolated strain and other strains related to Stenotrophomonas maltophilia in the GenBank database. The optimal conditions were investigated to be pH 5 at 30 °C, after 24 h using 5 mg/l MB showing optimum decolorization percentage (61.3%). Microbial toxicity study demonstrated relative reduction in the toxicity of MB decolorized products on test bacteria. Mechanism of color removal was proved by both biosorption and biodegradation, where heat-killed and live cells showed 43 and 52% of decolorization, respectively, as a maximum value after 24-h incubation. It was demonstrated that the mechanism of color removal is by adsorption. Therefore, good performance of S maltophilia in MB color removal reinforces the exploitation of these bacteria in environmental clean-up and restoration of the ecosystem.
Evaluation of Resuspension from Propeller Wash in DoD Harbors
2016-09-01
contaminants) concentrations in the total, sand , silt, clay, and dissolved fractions. Information in the middle represents the filtration sequence...April 2012 in San Diego Bay. Each metal is provided as the percentage fraction for clay (grey), silt (green), sand (red) and total (blue), the same...middle), and sand (bottom) concentrations for the three locations (see Figure 6-33
Causal Perception of Action-and-Reaction Sequences in 8- to 10-Month-Olds
ERIC Educational Resources Information Center
Schlottmann, Anne; Surian, Luca; Ray, Elizabeth D.
2009-01-01
Four experiments with 202 8- to 10-month-old infants studied their sensitivity to causation-at-a-distance in schematic events seen as goal-directed action and reaction by adults and whether this depends on attributes associated with animate agents. In Experiment 1, a red square moved toward a blue square without making contact; in "reaction"…
Blue light photoreceptors and methods of using the same
Cashmore, Anthony Robert; Ahmad, Margaret; Lin, Chentao
1998-01-01
The invention features a substantially pure preparation of a nucleic acid encoding a HY4 or a HY4-related gene. The invention further features transgenic plants encoding a HY4 gene having a shorter stem than substantially homozygous wild type nontransgenic plants; and, transgenic plants comprising complementary HY4 sequences having a longer stem than substantially homozygous wild type nontransgenic plants.
Isolation of prolactin and growth hormone from the pituitary of the holostean fish Amia calva.
Dores, R M; Noso, T; Rand-Weaver, M; Kawauchi, H
1993-06-01
Pituitaries from adult male and female Amia calva (Order Holostei) were acid extracted and fractionated by gel filtration column chromatography and reversed-phase high performance liquid chromatography. This two-step isolation procedure yielded homogeneous pools of Amia prolaction (PRL) and growth hormone (GH). The amino acid composition of both purified polypeptides was determined. Primary sequence analysis of the first 22 positions at the N-terminal of Amia PRL revealed that this region has 63% sequence identity with eel PRL-1. The N-terminal region of Amia PRL lacks the disulfide bridge which is characteristic of tetrapod PRLs. Primary sequence analysis of the first 24 positions at the N-terminal of Amia GH revealed that this region has 62% sequence identity with eel GH and 54% sequence identity with both blue shark GH and sea turtle GH. Based on N-terminal analysis, it appears that Amia PRL and GH are more closely related to teleost PRLs and GHs than they are to tetrapod PRLs and GHs.
Wang, Xiao-ting; Liu, Da-wei; Zhang, Hong-min; He, Huai-wu; Liu, Ye; Chai, Wen-zhao; Du, Wei
2012-12-01
To investigate the effect of the bedside lung ultrasound in emergency(BLUE)-plus lung ultrasound protocol on lung consolidation and atelectasis of critical patients. All patients who need to receive mechanical ventilation for more than 48 hours in ICU from June 2010 to December 2011 in Peking Union Medical College Hospital were included in the study. BLUE-plus and BLUE lung ultrasound, bedside X-ray, lung CT examination were performed on all patients at the same time. The condition of lung consolidation and atelectasis discovered by BLUE-plus lung ultrasound protocol was recorded and compared with bedside X-ray or lung CT. The difference in assessment of lung consolidation and atelectasis between BLUE-plus lung ultrasound protocol and BLUE protocol was compared. A total of 78 patients were finally enrolled in the study. The lung CT found 70 cases (89.74%) had different degrees of lung consolidation and atelectasis. The sensitivity, specificity and diagnostic accuracy of lung consolidation and atelectasis by the bedside chest X-ray were 31.29%, 75.00% and 38.46%, respectively. BLUE-plus lung ultrasound protocol found 68 cases with lung consolidation and atelectasis, and its sensitivity, specificity, and diagnostic accuracy were 95.71%, 87.50% and 94.87%, respectively, which were significantly higher than those of lung CT. BLUE protocol found 48 cases of lung consolidation and atelectasis, and its sensitivity, specificity, and diagnostic accuracy were 65.71%, 75.00% and 66.67%, respectively. The position of lung consolidation and atelectasis which hadn't been found by BLUE protocol was mainly proved to be located in the basement of lung by lung CT. The incidence of lung consolidation and atelectasis in critical patients who received mechanical ventilation is high. The BLUE-plus lung ultrasound protocol has a relatively higher sensitivity, specificity and diagnostic accuracy for consolidation and atelectasis, which can find majority of consolidation and atelectasis. As BLUE-plus lung ultrasound is a bedside noninvasive method allowing immediate assessment of most lung consolidation and atelectasis, it will be likely the alternative of the CT and play a key role in assessment of lung consolidation and atelectasis.
Zhang, Duo; Zhang, Hui; Zhang, Xiaohong; Sham, Tsun-Kong; Hu, Yongfeng; Sun, Xuhui
2016-03-07
The electronic structure and optical properties of di[4-(4-diphenylaminophenyl)phenyl]sulfone (denoted as DAPSF), a highly efficient fluorophor, have been investigated using X-ray excited optical luminescence (XEOL) and X-ray absorption near edge structure (XANES) spectroscopy at excitation energies across the C, N, O K-edges and the sulfur K-edge. The results indicate that the blue luminescence is mainly related to the sulfur functional group.
DOE Office of Scientific and Technical Information (OSTI.GOV)
White, J.D.L.; Vallier, T.; Stanley, G.D. Jr.
1992-08-01
Middle Jurassic strata atop the Wallowa terrane in northeastern Oregon link the Wallowa, Izee, and Olds Ferry terranes as related elements of a single long-lived and complex oceanic feature, the Blue Mountains island arc. Middle Jurassic strata in the Wallowa terrane include a dacitic ash-flow deposit and contain fossil corals and bivalves of North American affinity. Plant fossils in fluvial sandstones support a Jurassic age and indicate a seasonal temperate climate. Corals in a transgressive sequence traditionally overlying the fluvial units are of Bajocian age and are closely related to endemic varieties of the Western Interior embayment. They are unlikemore » Middle Jurassic corals in other Cordilleran terranes; their presence suggests that the Blue Mountains island arc first approached the North American craton at high paleolatitudes in Middle Jurassic time. The authors consider the Bajocian marine strata and underlying fluvial volcaniclastic units to be a basin-margin equivalent of the Izee terrane, a largely Middle Jurassic (Bajocian) succession of basinal volcaniclastic and volcanic rocks known to overlie the Olds Ferry and Baker terranes.« less
[Methanotrophs and methylobacteria are found in woody plant tissues within a winter period].
Doronina, N V; Ivanova, E G; Suzina, N F; Trotsenko, Iu A
2004-01-01
Samples of tree seeds, buds, and needles collected within a winter period at ambient temperatures from -11 to -17 degrees C were analyzed for the presence of methylotrophic microflora. Thin sections of blue spruce needles were found to contain bacteria morphologically close to pink-pigmented methylobacteria. The methylobacteria that were isolated in pure cultures from samples of linden seeds and buds, pine and blue spruce needles, as well as of lilac, maple, and apple buds, were classified into the genera Methylobacterium and Paracoccus based on the data of morphological studies, enzyme assay, and DNA-DNA hybridization analysis. The methanotrophs that were isolated in pure cultures from samples of linden buds and blue spruce needles were identified into the genus Methylocystis based on the data of morphological studies, enzyme assay, DNA-DNA hybridization, and the phylogenetic analysis of the particulate methane monooxygenase gene pmoA sequences. The inference is made that aerobic methylotrophic bacteria are permanently associated with plants. At the beginning of the vegetative period in spring, the phyllosphere of coniferous and deciduous trees is colonized by the methylotrophic bacteria that have wintered inside plant tissues.
Distance and absolute magnitudes of the brightest stars in the dwarf galaxy Sextans A
NASA Technical Reports Server (NTRS)
Sandage, A.; Carlson, G.
1982-01-01
In an attempt to improve present bright star calibration, data were gathered for the brightest red and blue stars and the Cepheids in the Im V dwarf galaxy, Sextans A. On the basis of a magnitude sequence measured to V and B values of about 22 and 23, respectively, the mean magnitudes of the three brightest blue stars are V=17.98 and B=17.88. The three brightest red supergiants have V=18.09 and B=20.14. The periods and magnitudes measured for five Cepheids yield an apparent blue distance modulus of 25.67 + or - 0.2, via the P-L relation, and the mean absolute magnitudes of V=-7.56 and B=-5.53 for the red supergiants provide additional calibration of the brightest red stars as distance indicators. If Sextans A were placed at the distance of the Virgo cluster, it would appear to have a surface brightness of 23.5 mag/sq arcec. This, together with the large angular diameter, would make such a galaxy easily discoverable in the Virgo cluster by means of ground-based surveys.
NASA Astrophysics Data System (ADS)
Miao, Yanqin; Wang, Kexiang; Zhao, Bo; Gao, Long; Tao, Peng; Liu, Xuguang; Hao, Yuying; Wang, Hua; Xu, Bingshe; Zhu, Furong
2018-01-01
By incorporating ultrathin (<0.1 nm) green, yellow, and red phosphorescence layers with different sequence arrangements in a blue fluorescence layer, four unique and simplified fluorescence/phosphorescence (F/P) hybrid, white organic light-emitting diodes (WOLEDs) were obtained. All four devices realize good warm white light emission, with high color rending index (CRI) of >80, low correlated color temperature of <3600 K, and high color stability at a wide voltage range of 5 V-9 V. These hybrid WOLEDs also reveal high forward-viewing external quantum efficiencies (EQE) of 17.82%-19.34%, which are close to the theoretical value of 20%, indicating an almost complete exciton harvesting. In addition, the electroluminescence spectra of the hybrid WOLEDs can be easily improved by only changing the incorporating sequence of the ultrathin phosphorescence layers without device efficiency loss. For example, the hybrid WOLED with an incorporation sequence of ultrathin red/yellow/green phosphorescence layers exhibits an ultra-high CRI of 96 and a high EQE of 19.34%. To the best of our knowledge, this is the first WOLED with good tradeoff among device efficiency, CRI, and color stability. The introduction of ultrathin (<0.1 nm) phosphorescence layers can also greatly reduce the consumption of phosphorescent emitters as well as simplify device structures and fabrication process, thus leading to low cost. Such a finding is very meaningful for the potential commercialization of hybrid WOLEDs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Layton, A.D.; Cross, F.T.; Steigler, G.L.
1994-12-31
We have exposed Big Blue{trademark} transgenic mice by inhalation to 320, 640 and 960 Working Level Months (WLM) of radon progeny. Mice were sacrificed after 3, 6 and 9 days; the time periods required to obtain the exposures. Control mice were also sacrificed at each time interval. In each case all tissues were excised, flash frozen in liquid nitrogen, and stored at -80{degrees}C for further analysis. Twelve lacI mutations have been isolated from the lung tissue of a mouse from the 960-WLM exposure group; the lacI genes from these mutants have been sequenced. Sequence data indicate that three of themore » mutants have a C;G deletion at BP 978 and are possibly clonal in origin. Two mutants have multiple events within the gene: one has a an A:T to C:G transversion and a C:G insertion separated by 291 BPs; the second has a G:C to A:T transition as well as an A:T deletion followed by 6 base pairs downstream by a T:A insertion. Other mutations include a single G:C to A:T transition, a two base pair deletion, and a C:G to T:A transition. Mutant plaques are being evaluated from individual mice at other dose levels. Time course experiments are also planned. These studies will help define the molecular fine structure of mutations induced by high-LET radiation exposure.« less
The evolutionary sequence of post-starburst galaxies
NASA Astrophysics Data System (ADS)
Wilkinson, C. L.; Pimbblet, K. A.; Stott, J. P.
2017-12-01
There are multiple ways in which to select post-starburst galaxies in the literature. In this work, we present a study into how two well-used selection techniques have consequences on observable post-starburst galaxy parameters, such as colour, morphology and environment, and how this affects interpretations of their role in the galaxy duty cycle. We identify a master sample of H δ strong (EWH δ > 3Å) post-starburst galaxies from the value-added catalogue in the seventh data release of the Sloan Digital Sky Survey (SDSS DR7) over a redshift range 0.01 < z < 0.1. From this sample we select two E+A subsets, both having a very little [O II] emission (EW_[O II] > -2.5 Å) but one having an additional cut on EWHα (>-3 Å). We examine the differences in observables and AGN fractions to see what effect the H α cut has on the properties of post-starburst galaxies and what these differing samples can tell us about the duty cycle of post-starburst galaxies. We find that H δ strong galaxies peak in the 'blue cloud', E+As in the 'green valley' and pure E+As in the 'red sequence'. We also find that pure E+As have a more early-type morphology and a higher fraction in denser environments compared with the H δ strong and E+A galaxies. These results suggest that there is an evolutionary sequence in the post-starburst phase from blue discy galaxies with residual star formation to passive red early-types.
Boccalandro, Hernán E.; Giordano, Carla V.; Ploschuk, Edmundo L.; Piccoli, Patricia N.; Bottini, Rubén; Casal, Jorge J.
2012-01-01
Leaf epidermal peels of Arabidopsis (Arabidopsis thaliana) mutants lacking either phototropins 1 and 2 (phot1 and phot2) or cryptochromes 1 and 2 (cry1 and cry2) exposed to a background of red light show severely impaired stomatal opening responses to blue light. Since phot and cry are UV-A/blue light photoreceptors, they may be involved in the perception of the blue light-specific signal that induces the aperture of the stomatal pores. In leaf epidermal peels, the blue light-specific effect saturates at low irradiances; therefore, it is considered to operate mainly under the low irradiance of dawn, dusk, or deep canopies. Conversely, we show that both phot1 phot2 and cry1 cry2 have reduced stomatal conductance, transpiration, and photosynthesis, particularly under the high irradiance of full sunlight at midday. These mutants show compromised responses of stomatal conductance to irradiance. However, the effects of phot and cry on photosynthesis were largely nonstomatic. While the stomatal conductance phenotype of phot1 phot2 was blue light specific, cry1 cry2 showed reduced stomatal conductance not only in response to blue light, but also in response to red light. The levels of abscisic acid were elevated in cry1 cry2. We conclude that considering their effects at high irradiances cry and phot are critical for the control of transpiration and photosynthesis rates in the field. The effects of cry on stomatal conductance are largely indirect and involve the control of abscisic acid levels. PMID:22147516
Boccalandro, Hernán E; Giordano, Carla V; Ploschuk, Edmundo L; Piccoli, Patricia N; Bottini, Rubén; Casal, Jorge J
2012-03-01
Leaf epidermal peels of Arabidopsis (Arabidopsis thaliana) mutants lacking either phototropins 1 and 2 (phot1 and phot2) or cryptochromes 1 and 2 (cry1 and cry2) exposed to a background of red light show severely impaired stomatal opening responses to blue light. Since phot and cry are UV-A/blue light photoreceptors, they may be involved in the perception of the blue light-specific signal that induces the aperture of the stomatal pores. In leaf epidermal peels, the blue light-specific effect saturates at low irradiances; therefore, it is considered to operate mainly under the low irradiance of dawn, dusk, or deep canopies. Conversely, we show that both phot1 phot2 and cry1 cry2 have reduced stomatal conductance, transpiration, and photosynthesis, particularly under the high irradiance of full sunlight at midday. These mutants show compromised responses of stomatal conductance to irradiance. However, the effects of phot and cry on photosynthesis were largely nonstomatic. While the stomatal conductance phenotype of phot1 phot2 was blue light specific, cry1 cry2 showed reduced stomatal conductance not only in response to blue light, but also in response to red light. The levels of abscisic acid were elevated in cry1 cry2. We conclude that considering their effects at high irradiances cry and phot are critical for the control of transpiration and photosynthesis rates in the field. The effects of cry on stomatal conductance are largely indirect and involve the control of abscisic acid levels.
Silva, Tatiane F; Romanel, Elisson A C; Andrade, Roberto R S; Farinelli, Laurent; Østerås, Magne; Deluen, Cécile; Corrêa, Régis L; Schrago, Carlos E G; Vaslin, Maite F S
2011-08-24
In response to infection, viral genomes are processed by Dicer-like (DCL) ribonuclease proteins into viral small RNAs (vsRNAs) of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some groups of viruses. However, nothing is known about the vsRNAs produced during infections of members of the economically important family Luteoviridae, a group of phloem-restricted viruses. Here, we report the characterization of a population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV), a member of the genus Polerovirus, family Luteoviridae. Deep sequencing of small RNAs (sRNAs) from leaves of CLRDV-infected cotton plants revealed that the vsRNAs were 21- to 24-nucleotides (nt) long and that their sequences matched the viral genome, with higher frequencies of matches in the 3- region. There were equivalent amounts of sense and antisense vsRNAs, and the 22-nt class of small RNAs was predominant. During infection, cotton Dcl transcripts appeared to be up-regulated, while Dcl2 appeared to be down-regulated. This is the first report on the profile of sRNAs in a plant infected with a virus from the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAs. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpectedly high accumulation of 22-nt vsRNAs are discussed. CLRDV is the causal agent of Cotton blue disease, which occurs worldwide. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases.
Suebsing, R; Pradeep, P J; Jitrakorn, S; Sirithammajak, S; Kampeera, J; Turner, W A; Saksmerprome, V; Withyachumnarnkul, B; Kiatpathomchai, W
2016-07-01
Infectious spleen and kidney necrosis virus (ISKNV) has recently been recognized as a causative agent of serious systemic disease in tilapia. Our objective was to establish a new colorimetric loop-mediated isothermal amplification (LAMP) assay with pre-addition of hydroxynapthol blue (blue-LAMP) to investigate ISKNV transmission in tilapia. The blue-LAMP, targeting a major capsid protein gene of ISKNV, was conducted at 65°C for 45 min, allowing unaided visual detection of the pathogen based on colour change without cross-amplification of other known fish pathogens tested. Comparison of blue-LAMP and PCR assays revealed a higher detection level for blue-LAMP assay (41·33%) in a population of farmed tilapia infected with ISKNV. The investigation of ISKNV transmission pattern in farmed red tilapia using the blue-LAMP revealed a possible matroclinical form. The presence of ISKNV in the gonad samples was confirmed by in situ LAMP assay. Positive signals only appeared in ovarian follicles, and not in oocytes. Moreover, tissue tropism assay revealed that the brain was the main target organ in both farmed red tilapia (40%) and Nile tilapia (20%). The developed blue-LAMP assay has the potential to be used as a viable tool for screening covert and natural infections of ISKNV in tilapia. The evidence of vertical transmission of ISKNV infection in tilapia indicates the seriousness of this disease and will require a close attention and collaboration between tilapia hatcheries and disease experts in order to find a solution. The new blue-LAMP assay is a time-saving and economically viable detection tool, which allows unaided visual detection for ISKNV in tilapia, and it could be applicable for field applications. Evidence on the vertical transmission of ISKNV in farmed tilapia suggests a need for developing farm management practices to control the spread of virus in aquaculture industries. © 2016 The Society for Applied Microbiology.
Distribution and population genetics of walleye and sauger
Haponski, Amanda E.; Sloss, Brian L.
2014-01-01
Conserving genetic diversity and local adaptations are management priorities for wild populations of exploited species, which increasingly are subject to climate change, habitat loss, and pollution. These constitute growing concerns for the walleye Sander vitreus, an ecologically and economically valuable North American temperate fish with large Laurentian Great Lakes' fisheries. This study compares genetic diversity and divergence patterns across its widespread native range using mitochondrial (mt) DNA control region sequences and nine nuclear DNA microsatellite (μsat) loci, examining historic and contemporary influences. We analyze the genetic and morphological characters of a putative endemic variant– “blue pike” S. v. “glaucus” –described from Lakes Erie and Ontario, which became extinct. Walleye with turquoise-colored mucus also are evaluated, since some have questioned whether these are related to the “blue pike”.
Li, Weiwen; Dai, Xiaojie; Zhu, Jiangfeng; Tian, Siquan; He, Shan; Wu, Feng
2017-07-01
Six hundred and ninety-seven base pairs of cytochrome b gene of mtDNA was sequenced and analyzed for 78 blue shark Prionace glauca individuals from three sampled locations in the central Pacific Ocean (CPO). In total, three polymorphic sites were detected which defined four haplotypes. The haplotype diversity (h) ranged from 0.517 to 0.768, and nucleotide diversity (π) was between 0.0007 and 0.0011. Analysis of molecular variance indicated a non-significant differentiation among subpopulations. Furthermore, pairwise F ST score analysis revealed a non-significant differentiation among three sampled regions. Generally, low genetic differences were found between different geographic locations in the CPO. This study suggests a single panmictic population of P. glauca in the CPO.
Accurate age determinations of several nearby open clusters containing magnetic Ap stars
NASA Astrophysics Data System (ADS)
Silaj, J.; Landstreet, J. D.
2014-06-01
Context. To study the time evolution of magnetic fields, chemical abundance peculiarities, and other characteristics of magnetic Ap and Bp stars during their main sequence lives, a sample of these stars in open clusters has been obtained, as such stars can be assumed to have the same ages as the clusters to which they belong. However, in exploring age determinations in the literature, we find a large dispersion among different age determinations, even for bright, nearby clusters. Aims: Our aim is to obtain ages that are as accurate as possible for the seven nearby open clusters α Per, Coma Ber, IC 2602, NGC 2232, NGC 2451A, NGC 2516, and NGC 6475, each of which contains at least one magnetic Ap or Bp star. Simultaneously, we test the current calibrations of Te and luminosity for the Ap/Bp star members, and identify clearly blue stragglers in the clusters studied. Methods: We explore the possibility that isochrone fitting in the theoretical Hertzsprung-Russell diagram (i.e. log (L/L⊙) vs. log Te), rather than in the conventional colour-magnitude diagram, can provide more precise and accurate cluster ages, with well-defined uncertainties. Results: Well-defined ages are found for all the clusters studied. For the nearby clusters studied, the derived ages are not very sensitive to the small uncertainties in distance, reddening, membership, metallicity, or choice of isochrones. Our age determinations are all within the range of previously determined values, but the associated uncertainties are considerably smaller than the spread in recent age determinations from the literature. Furthermore, examination of proper motions and HR diagrams confirms that the Ap stars identified in these clusters are members, and that the presently accepted temperature scale and bolometric corrections for Ap stars are approximately correct. We show that in these theoretical HR diagrams blue stragglers are particularly easy to identify. Conclusions: Constructing the theoretical HR diagram of a nearby open cluster makes possible an accurate age determination, with well defined uncertainty. This diagnostic of a cluster also provides a useful tool for studying unusual stars such as Ap stars and blue stragglers. Table 3 is available in electronic form at http://www.aanda.org
A Near-Infrared Surface Compositional Analysis of Blue Straggler Stars in Open Cluster M67
NASA Astrophysics Data System (ADS)
Seifert, Richard; Gosnell, Natalie M.; Sneden, Chris
2017-06-01
Blue straggler stars (BSSs) are stars whose evolutions have been directly impacted by binary system interactions. By obtaining additional mass from a companion, BSSs are able to live prolonged lives on the main sequence. BSSs bring confusions to studies that rely on a standard stellar evolutionary track when modeling stellar populations, since the presence of BSSs can make a population appear younger than it actually is. It is important to have a better understanding of the mechanisms that drive BSS formation so that BSSs may be correctly accounted for in future studies.Blue stagglers in clusters primarily form in one of two ways; either from a close binary system in which one star accretes mass from its companion star or from a hierarchical trinary system in which a close inner binary merges as a result of perturbations from a farther-orbiting third star. In order to investigate the nature of this mass transfer, We obtained IGRINS H-band high resolution spectra of 6 BSSs and 12 red giant stars in open cluster M67. Using a grid of synthetic spectra obtained from the line analysis code MOOG, we identified and fit abundances for absorption lines of iron, silicon, and carbon. Depending on the evolutionary stage of the donor star, the abundance of carbon in the resulting BSS can be affected by mixing during the mass transfer. By analyzing the abundance of carbon in our targets, we find that [Fe/H] ~= 0 and [C/H] ~= 0. We see no evidence of depletion of carbon from RGB-phase mass transfer or enhancement of carbon from AGB-phase mass transfer, implying that the mass transfer occured earlier in the donar star's evolution.Funding for this research comes from the John W. Cox endowment for the Advanced Studies in Astronomy. For support of this work we acknowledge NSF grants AST-1211585 and AST-1616040 to CS. The successful development of the IGRINS spectrograph has resulted from the combined efforts of teams at the University of Texas at Austin and the Korea Astronomy and Space Science Institute; their work is gratefully acknowledged.
Drewlo, Sascha; Brämer, Christian O.; Madkour, Mohamed; Mayer, Frank; Steinbüchel, Alexander
2001-01-01
On complex medium Escherichia coli strains carrying hybrid plasmid pBEC/EE:11.0, pSKBEC/BE:9.0, pSKBEC/PP:3.3, or pSKBEC/PP:2.4 harboring genomic DNA of Ralstonia eutropha HF39 produced a blue pigment characterized as indigo by several chemical and spectroscopic methods. A 1,251-bp open reading frame (bec) was cloned and sequenced. The deduced amino acid sequence of bec showed only weak similarities to short-chain acyl-coenzyme A dehydrogenases, and the gene product catalyzed formation of indoxyl, a reactive preliminary stage for production of indigo. PMID:11282658
Conductive stability of graphene on PET and glass substrates under blue light irradiation
NASA Astrophysics Data System (ADS)
Cao, Xueying; Liu, Xianming; Li, Xiangdi; Lei, Xiaohua; Chen, Weimin
2018-01-01
Electrical properties of graphene transparent conductive film under visible light irradiation are investigated. The CVD-grown graphene on Polyethylene Terephthalate (PET) and glass substrates for flexible and rigid touch screen display application are chosen for research. The resistances of graphene with and without gold trichloride (AuCl3) doping are measured in vacuum and atmosphere environment under blue light irradiation. Results show that the conductivities of all samples change slowly under light irradiation. The change rate and degree are related to the substrate material, doping, environment and lighting power. Graphene on flexible PET substrate is more stable than that on rigid glass substrate. Doping can improve the electrical conductivity but induce instability under light irradiation. Finally, the main reason resulting in the graphene resistance slowly increasing under blue light irradiation is analyzed.
Blue light decreases tanshinone IIA content in Salvia miltiorrhiza hairy roots via genes regulation.
Chen, Ing-Gin J; Lee, Meng-Shiou; Lin, Ming-Kuem; Ko, Chia-Yun; Chang, Wen-Te
2018-06-01
The effect of light-emitting diodes (LEDs) on the production of secondary metabolites in medicinal plants and hairy roots is receiving much attention. The roots and rhizomes of the traditional Chinese medicinal plant Salvia miltiorrhiza Bunge are widely used for treating cardiovascular and cerebrovascular diseases. The main components are liposoluble tanshinones and hydrophilic phenolic acids. Moreover, hairy root culture of S. miltiorrhiza has been used in research of valuable plant-derived secondary metabolites. In this study, we examined the effect of LEDs with different combinations of wavelengths on the content of the main components in hairy roots of S. miltiorrhiza. Tanshinone IIA (TSIIA) content in hairy roots was significantly decreased with all light treatments containing blue light by >60% and was 9 times lower with LED treatment duration changed from 1 week to 3 weeks. HMGR, DXS2, DXR, GGPPS, CPS and CYP76AH1 genes involved in the tanshinone biosynthesis pathway were downregulated by blue light. Furthermore, light quality treatments have different effect on the accumulation of phenolic acids in hairy roots of S. miltiorrhiza. The light treatments 6R3B, 6B3IR, 7RGB and 2R6BUV for 3 weeks could increase rosmarinic acid (RA) content slightly but not salvianolic acid B (SAB) content. Different secondary metabolite contents could be regulated by different wavelength combinations of LEDs. Blue light could reduce TSIIA content in hairy roots of S. miltiorrhiza via gene regulation. Copyright © 2018. Published by Elsevier B.V.
NASA Technical Reports Server (NTRS)
Goins, G. D.; Yorio, N. C.; Sanwo, M. M.; Brown, C. S.; Sager, J. C. (Principal Investigator)
1997-01-01
Red light-emitting diodes (LEDs) are a potential light source for growing plants in spaceflight systems because of their safety, small mass and volume, wavelength specificity, and longevity. Despite these attractive features, red LEDs must satisfy requirements for plant photosynthesis and photomorphogenesis for successful growth and seed yield. To determine the influence of gallium aluminium arsenide (GaAlAs) red LEDs on wheat photomorphogenesis, photosynthesis, and seed yield, wheat (Triticum aestivum L., cv. 'USU-Super Dwarf') plants were grown under red LEDs and compared to plants grown under daylight fluorescent (white) lamps and red LEDs supplemented with either 1% or 10% blue light from blue fluorescent (BF) lamps. Compared to white light-grown plants, wheat grown under red LEDs alone demonstrated less main culm development during vegetative growth through preanthesis, while showing a longer flag leaf at 40 DAP and greater main culm length at final harvest (70 DAP). As supplemental BF light was increased with red LEDs, shoot dry matter and net leaf photosynthesis rate increased. At final harvest, wheat grown under red LEDs alone displayed fewer subtillers and a lower seed yield compared to plants grown under white light. Wheat grown under red LEDs+10% BF light had comparable shoot dry matter accumulation and seed yield relative to wheat grown under white light. These results indicate that wheat can complete its life cycle under red LEDs alone, but larger plants and greater amounts of seed are produced in the presence of red LEDs supplemented with a quantity of blue light.
Reflection characterization of nano-sized dielectric structure in Morpho butterfly wings
NASA Astrophysics Data System (ADS)
Zhu, Dong
2017-10-01
Morpho butterflies living in Central and South America are well-known for their structural-colored blue wings. The blue coloring originates from the interaction of light with nano-sized dielectric structures that are equipped on the external surface of scales covering over their wings. The high-accuracy nonstandard finite-difference time domain (NS-FDTD) method is used to investigate the reflection characterization from the nanostructures. In the NS-FDTD calculation, a computational model is built to mimic the actual tree-like multilayered structures wherever possible using the hyperbolic tangent functions. It is generally known that both multilayer interference and diffraction grating phenomena can occur when light enters the nano-sized multilayered structure. To answer the question that which phenomenon is mainly responsible for the blue coloring, the NS-FDTD calculation is performed under various incidence angles at wavelengths from 360 to 500 nm. The calculated results at one incident wavelength under different incidence angles are visualized in a two-dimensional mapping image, where horizontal and vertical axes are incidence and reflection angles, respectively. The images demonstrate a remarkable transition from a ring-like pattern at shorter wavelengths to a retro-reflection pattern at longer wavelengths. To clarify the origin of the pattern transition, the model is separated into several simpler parts and compared their mapping images with the theoretical diffraction calculations. It can be concluded that the blue coloring at longer wavelengths is mainly caused by the cooperation of multilayer interference and retro-reflection while the effect of diffraction grating is predominant at shorter wavelengths.
NASA Astrophysics Data System (ADS)
Kochiashvili, Nino; Beradze, Sophie; Kochiashvili, Ia; Natsvlishvili, Rezo; Vardosanidze, Manana
Evolutionary scenarios of massive stars were revised in recent decades, after finding "unusual", blue progenitor of SN 1987A and after detecting the more massive stars than the accepted 120 M ⊙ maximum limit of stellar masses. A very important relation exists between WR and LBV stars. They represent the earlier, pre-SN evolutionary states of massive stars. WR and LBV stars and "classic" evolutionary scheme of the relation between the different type massive stars are discussed in this article. There also exist the newest evolutionary scenarios for low metallicity massive stars, which give us a different picture of their post main-sequence evolution. There is a rather good tradition of observations and investigations of massive stars at Abastumani Astrophysical Observatory. The authors discuss the new findings on the fate of P Cygni, the LBV star. These results on the reddening of the star and about its next possible outburst in the near future were obtained on the basis of UBV long-term electrophotometric observations of P Cygni by Eugene Kharadze and Nino Magalashvili. The observations were held in 1951-1983 at Abastumani Observatory using 33-cm and 48-cm reflectors.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Staedtler, F.; Locher, F.; Sreenan, G.
1997-10-01
In order to evaluate the in vivo genotoxic potential of three putative genotoxic mouse liver carcinogens, high doses of 4-chloro-o-phenylenediamine, 2-nitro-p-phenylenediamine and 2, 4-diaminotoluene were tested short term in the Big Blue{reg_sign} transgenic mouse mutation assay. Small statistically significant increases in the lacI mutant frequencies in the liver by factors 1.7 to 2.0 were found. A representative number of 347 lacI mutants isolated from liver tissue of male and female animals were analyses by DNA sequencing. The mutational spectra were examined with the Adams-Skopek algorithm. The spontaneous mutational spectra from untreated male and female animals were similar and consistent withmore » spectral Big Blue{reg_sign} control data stored in the lacI database. Most of the background mutations were located in the 5{prime} portion of the coding region of the lacI gene. Single base substitutions were most prominent. G:C to A:T transitions and G:C to T:A transversions occurred predominatly and were preferentially located at CpG sites. Despite the increases observed in the mutant frequencies of the treated animals, the corresponding mutational spectra did not differ from the controls. However, it is possible that certain classes of point mutations were substantially increased but not detected due to the limited number of sequenced mutants. In two animals treated with 2, 4- diaminotoluene unusually high mutant frequencies and the multiple occurrence of certain mutations in the liver was observed. From one of these animals six lacI mutants isolated from colon tissue were all different. Since 2, 4-diaminotoluene was shown to induce liver cell proliferation these results may reflect clonal expansion of single mutated liver cells.« less
1990-08-15
the same sequences and chira Jies of the amino acids as reported earlier in other microcystins."’ ’ All contain two variant amino acids in the L... Williams , D. H.; Santikarn, S.; Smith, R. J.; Hammond, S. J., Chem. Soc. Perkin Tran., 1984, 2311. 2. Marfey, P. Carlsberg Res. Commun., 1984, 49, 591
NASA Astrophysics Data System (ADS)
Wagner, Bernd; Wennrich, Volker; Viehberg, Finn; Junginger, Annett; Kolvenbach, Anne; Rethemeyer, Janet; Schaebitz, Frank; Schmiedl, Gerhard
2018-04-01
A 12 m long sediment sequence was recovered from the eastern Dendi Crater lake, located on the central Ethiopian Plateau and in the region of the Blue Nile headwaters. 24 AMS radiocarbon dates from bulk organic carbon samples indicate that the sediment sequence spans the last ca. 12 cal kyr BP. Sedimentological and geochemical data from the sediment sequence that were combined with initial diatom information show only moderate change in precipitation and catchment runoff during that period, probably due to the elevated location of the study region in the Ethiopian highlands. Less humid conditions prevailed during the Younger Dryas (YD). After the return to full humid conditions of the African Humid Period (AHP), a 2 m thick tephra layer, probably originating from an eruption of the Wenchi crater 12 km to the west of the lake, was deposited at 10.2 cal kyr BP. Subsequently, single thin horizons of high clastic matter imply that short spells of dry conditions and significantly increased rainfall, respectively, superimpose the generally humid conditions. The end of the AHP is rather gradual and precedes relatively stable and less humid conditions around 3.9 cal kyr BP. Subsequently, slightly increasing catchment runoff led to sediment redeposition, increasing nutrient supply, and highest trophic states in the lake until 1.5 cal kyr BP. A highly variable increase in clastic matter indicates fluctuating and increasing catchment runoff over the last 1500 years. The data from Lake Dendi show, in concert with other records from the Nile catchment and the Eastern Mediterranean Sea (EMS), that the Blue Nile discharge was relatively high between ca. 10.0 and 8.7 cal kyr BP. Subsequent aridification peaked with some regional differences between ca. 4.0 and 2.6 cal kyr BP. Higher discharge in the Blue Nile hydraulic regime after 2.6 cal kyr BP is probably triggered by more local increase in rainfall, which is tentatively caused by a change in the influence of the Indian Ocean monsoon.
Custer, Christine M.; Suarez, S.A.; Olsen, D.A.
2004-01-01
The Great Blue Heron (Ardea herodias) and Great Egret (Ardea alba) nested in eight colonies along the Upper Mississippi River, USA, and individual birds were followed by airplane to feeding sites during the nesting seasons in 1995-1998. Both species used braided channel/backwater habitats for feeding more than expected, based on availability, and open pool and main navigation channel less than expected. Most individuals of both species fed 10 km away. Habitat and distance need to be considered simultaneously when assessing habitat quality for herons and egrets. The Great Blue Heron flew farther to feeding sites during the care-of-young period than during incubation and the Great Egret showed the opposite pattern. The Great Blue Heron tended to feed solitarily; only 10% of the feeding flights ended at a location where another heron was already present. About one-third of Great Egret feeding flights ended at a location with another egret already present. Colony placement on the landscape seemed to be a function of the feeding radius of each colony.
NASA Astrophysics Data System (ADS)
Hallam, D. F.; Maher, B. A.
1994-01-01
Palaeomagnetic measurements were made on samples extracted from a short sequence of early Pleistocene estuarine clays, now exposed in a sea cliff near Sheringham on the north Norfolk coast, UK. On the basis of earlier palynological work, these clays had been ascribed a Pastonian (late Tiglian) age. The clays show marked changes in colour, from reddish-brown at the top of the unit, to blue-grey in the middle, and grey-brown at the base. The palaeomagnetic data vary in close association with these colour changes. The top and basal brown clays show scattered normal directions of low intensity, while the middle blue clays show strongly clustered reversed directions, of much higher intensities. Some samples taken from the boundary between the middle blue clays and upper red clays show upon demagnetisation a normal overprint on a stable reversed polarity. Using high-gradient magnetic extraction, magnetic concentrates have been obtained from the strongly magnetic middle blue clays. The presence of iron sulphide minerals in these concentrates was identified using energy-dispersive X-ray analysis during scanning electron microscopy. More specifically, X-ray diffraction identifies greigite as the only detectable ferrimagnetic mineral in the magnetic concentrates. Rock magnetic measurements show clear qualitative differences in the magnetic mineralogies of the three clay subunits, but absolute identification of the magnetic mineralogy of the weakly magnetic upper and basal brown clays has not yet been possible. We interpret the sequence as a primary reversed polarity record. This record is carried by the iron sulphide greigate as a chemical remanence acquired during `syn'-depositional reduction of iron via the decomposition of organic material in these anoxic tidal clays. Subsequently, the upper and basl subunits of the clay have been oxidised by permeation of groundwater from the adjacent coarse-grained sediments. Most of the griegite in the oxidised margins of the clay has been altered as a result, to a new, less efficient magnetic recording material which thus carries a later, scattered, low-intensity, normal overprint.
[Demographic analysis of the blue shark, Prionace glauca, in the North Atlantic Ocean].
Gao, Chun-xia; Dai, Xiao-jie; Tian, Si-quan; Wu, Feng; Zhu, Jiang-feng
2016-02-01
The blue shark, Prionace glauca, is the main by-catch species in tuna longline fishery. As one of top species in the oceanic food webs, the blue shark plays an important role in the marine ecosystem. Traditional stock assessment methods are difficult to accurately evaluate the population dynamic for this shark because of limited data. Based on life-history parameters of the blue shark in the North Atlantic, demographic analysis was employed to estimate the demographic parameters and evaluate the potential exploitation for the blue shark. Moreover, we discussed the relationship between age at first capture and critical value of fishing mortality corresponding to the value of intrinsic rate of natural increase 0. The results showed that the survival rate (S) of blue shark from 0.719 to 0.820, intrinsic rate of natural increase (r0) from 0.250 to 0.381, time of population doubling (tx2) from 1.819 to 2.773 years, reproduction rate per generation (R0) from 6.600 to 22.255, and generation time (G) from 8.498 to 10.162 years. The sensitivity analysis for the life history parameters revealed that the uncertainties of natural mortality existed in the first age class, age at maturity and maximum age had slight influence on the demographic parameters. Fishing mortality (Fc) increased with the age at first capture. When the age at first capture (tc) was more than five, there was no obvious relationship between Fc and tc.
Operation of a P300-based brain-computer interface by individuals with cervical spinal cord injury.
Ikegami, Shiro; Takano, Kouji; Saeki, Naokatsu; Kansaku, Kenji
2011-05-01
This study evaluates the efficacy of a P300-based brain-computer interface (BCI) with green/blue flicker matrices for individuals with cervical spinal cord injury (SCI). Ten individuals with cervical SCI (age 26-53, all male) and 10 age- and sex-matched able-bodied controls (age 27-52, all male) with no prior BCI experience were asked to input hiragana (Japanese alphabet) characters using the P300 BCI with two distinct types of visual stimuli, white/gray and green/blue, in an 8×10 flicker matrix. Both online and offline performance were evaluated. The mean online accuracy of the SCI subjects was 88.0% for the white/gray and 90.7% for the green/blue flicker matrices. The accuracy of the control subjects was 77.3% and 86.0% for the white/gray and green/blue, respectively. There was a significant difference in online accuracy between the two types of flicker matrix. SCI subjects performed with greater accuracy than controls, but the main effect was not significant. Individuals with cervical SCI successfully controlled the P300 BCI, and the green/blue flicker matrices were associated with significantly higher accuracy than the white/gray matrices. The P300 BCI with the green/blue flicker matrices is effective for use not only in able-bodied subjects, but also in individuals with cervical SCI. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Principles of phosphorescent organic light emitting devices.
Minaev, Boris; Baryshnikov, Gleb; Agren, Hans
2014-02-07
Organic light-emitting device (OLED) technology has found numerous applications in the development of solid state lighting, flat panel displays and flexible screens. These applications are already commercialized in mobile phones and TV sets. White OLEDs are of especial importance for lighting; they now use multilayer combinations of organic and elementoorganic dyes which emit various colors in the red, green and blue parts of the visible spectrum. At the same time the stability of phosphorescent blue emitters is still a major challenge for OLED applications. In this review we highlight the basic principles and the main mechanisms behind phosphorescent light emission of various classes of photofunctional OLED materials, like organic polymers and oligomers, electron and hole transport molecules, elementoorganic complexes with heavy metal central ions, and clarify connections between the main features of electronic structure and the photo-physical properties of the phosphorescent OLED materials.
Brummelman, Jolanda; Veerman, Rosanne E.; Hamstra, Hendrik Jan; Deuss, Anna J. M.; Schuijt, Tim J.; Sloots, Arjen; Kuipers, Betsy; van Els, Cécile A. C. M.; van der Ley, Peter; Mooi, Frits R.; Han, Wanda G. H.
2014-01-01
Bordetella pertussis is a Gram-negative bacterium and the causative agent of whooping cough. Despite high vaccination coverage, outbreaks are being increasingly reported worldwide. Possible explanations include adaptation of this pathogen, which may interfere with recognition by the innate immune system. Here, we describe innate immune recognition and responses to different B. pertussis clinical isolates. By using HEK-Blue cells transfected with different pattern recognition receptors, we found that 3 out of 19 clinical isolates failed to activate Toll-like receptor 4 (TLR4). These findings were confirmed by using the monocytic MM6 cell line. Although incubation with high concentrations of these 3 strains resulted in significant activation of the MM6 cells, it was found to occur mainly through interaction with TLR2 and not through TLR4. When using live bacteria, these 3 strains also failed to activate TLR4 on HEK-Blue cells, and activation of MM6 cells or human monocyte-derived dendritic cells was significantly lower than activation induced by the other 16 strains. Mass spectrum analysis of the lipid A moieties from these 3 strains indicated an altered structure of this molecule. Gene sequence analysis revealed mutations in genes involved in lipid A synthesis. Findings from this study indicate that B. pertussis isolates that do not activate TLR4 occur naturally and that this phenotype may give this bacterium an advantage in tempering the innate immune response and establishing infection. Knowledge on the strategies used by this pathogen in evading the host immune response is essential for the improvement of current vaccines or for the development of new ones. PMID:25348634
NASA Astrophysics Data System (ADS)
Baldwin, A. T.; Watkins, L. L.; van der Marel, R. P.; Bianchini, P.; Bellini, A.; Anderson, J.
2016-08-01
We make use of the Hubble Space Telescope proper-motion catalogs derived by Bellini et al. to produce the first radial velocity dispersion profiles σ (R) for blue straggler stars (BSSs) in Galactic globular clusters (GCs), as well as the first dynamical estimates for the average mass of the entire BSS population. We show that BSSs typically have lower velocity dispersions than stars with mass equal to the main-sequence turnoff mass, as one would expect for a more massive population of stars. Since GCs are expected to experience some degree of energy equipartition, we use the relation σ \\propto {M}-η , where η is related to the degree of energy equipartition, along with our velocity dispersion profiles to estimate BSS masses. We estimate η as a function of cluster relaxation from recent Monte Carlo cluster simulations by Bianchini et al. and then derive an average mass ratio {M}{BSS}/{M}{MSTO}=1.50+/- 0.14 and an average mass {M}{BSS}=1.22+/- 0.12 M ⊙ from 598 BSSs across 19 GCs. The final error bars include any systematic errors that are random between different clusters, but not any potential biases inherent to our methodology. Our results are in good agreement with the average mass of {M}{BSS}=1.22+/- 0.06 M ⊙ for the 35 BSSs in Galactic GCs in the literature with properties that have allowed individual mass determination. Based on proprietary and archival 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.
NASA Astrophysics Data System (ADS)
Subramaniam, Annapurni; Sindhu, N.; Tandon, S. N.; Kameswara Rao, N.; Postma, J.; Côté, Patrick; Hutchings, J. B.; Ghosh, S. K.; George, K.; Girish, V.; Mohan, R.; Murthy, J.; Sankarasubramanian, K.; Stalin, C. S.; Sutaria, F.; Mondal, C.; Sahu, S.
2016-12-01
We present early results from the Ultra-Violet Imaging Telescope (UVIT) on board the ASTROSAT observatory. We report the discovery of a hot companion associated with one of the blue straggler stars (BSSs) in the old open cluster, NGC 188. Using fluxes measured in four filters in UVIT’s far-UV (FUV) channel, and two filters in the near-UV (NUV) channel, we have constructed the spectral energy distribution (SED) of the star WOCS-5885, after combining with flux measurements from GALEX, Ultraviolet Imaging Telescope, Ultraviolet Optical Telescope, SPITZER, WISE, and several ground-based facilities. The resulting SED spans a wavelength range of 0.15 μm to 7.8 μm. This object is found to be one of the brightest FUV sources in the cluster. An analysis of the SED reveals the presence of two components. The cooler component is found to have a temperature of 6000 ± 150 K, confirming that it is a BSS. Assuming it to be a main-sequence star, we estimate its mass to be ˜1.1-1.2 M ⊙. The hotter component, with an estimated temperature of 17,000 ± 500 K, has a radius of ˜ 0.6 R ⊙ and L ˜30 L ⊙. Bigger and more luminous than a white dwarf, yet cooler than a sub-dwarf, we speculate that it is a post-AGB/HB star that has recently transferred its mass to the BSS, which is known to be a rapid rotator. This binary system, which is the first BSS with a post-AGB/HB companion identified in an open cluster, is an ideal laboratory to study the process of BSS formation via mass transfer.
Cool transition region loops observed by the Interface Region Imaging Spectrograph
NASA Astrophysics Data System (ADS)
Huang, Z.; Xia, L.; Li, B.; Madjarska, M. S.
2015-12-01
An important class of loops in the solar atmosphere, cool transition region loops, have received little attention mainly due to instrumental limitations. We analyze a cluster of these loops in the on-disk active region NOAA 11934 recorded in a Si IV 1402.8 Å spectral raster and 1400Å slit-jaw (SJ) images taken by the Interface Region Imaging Spectrograph. We divide these loops into three groups and study their dynamics, evolution and interaction.The first group comprises geometrically relatively stable loops, which are finely scaled with 382~626 km cross-sections. Siphon flows in these loops are suggested by the Doppler velocities gradually changing from -10 km/s (blue-shifts) in one end to 20 km/s (red-shifts) in the other. Nonthermal velocities from 15 to 25 km/s were determined. The obtained physical properties suggest that these loops are impulsively heated by magnetic reconnection occurring at the blue-shifted footpoints where magnetic cancellation with a rate of 1015 Mx/s is found. The released magnetic energy is redistributed by the siphon flows. The second group corresponds to two active footpoints rooted in mixed-magnetic-polarity regions. Magnetic reconnection in both footpoints is suggested by explosive-event line profiles with enhanced wings up to 200 km/s and magnetic cancellation with a rate of ~1015 Mx/s. In the third group, an interaction between two cool loop systems is observed. Mixed-magnetic polarities are seen in their conjunction area where explosive-event line profiles and magnetic cancellation with a rate of 3×1015 Mx/s are found. This is a clear indication that magnetic reconnection occurs between these two loop systems. Our observations suggest that the cool transition region loops are heated impulsively most likely by sequences of magnetic reconnection events.
Observationally Testing the Triple Origin of Blue Straggler Stars with Near-Infrared Spectroscopy
NASA Astrophysics Data System (ADS)
Kohler, Jacob P.; Gosnell, Natalie M.; Sokal, Kimberly R.; Mace, Gregory N.
2018-01-01
Presented are results to constrain blue straggler star (BSS) formation mechanisms in open cluster NGC 188 using data from the Immersion Grating INfrared Spectrometer (IGRINS) while at the Discovery Channel Telescope. The majority (at least 16 of 21) of NGC 188s BSSs are binaries, and, to date, seven white dwarf (WD) companions have been detected. This leaves at least nine undetected companion stars. Observations show a sharp peak of the BSSs companion mass distribution at 0.5 solar masses, highly suggestive of a WD or M-type main sequence (MS) star. Under our tested formation mechanism, the progenitors of BSSs are arranged in primordial hierarchical triple star systems that dynamically evolve through the Kozai-cycle tidal friction (KCTF) process into a binary composed of a BSS and, statistically, an M dwarf companion. We test for the presence of an M dwarf by cross-correlating a near-IR spectrum with both a BSS template and an M dwarf template. We present, for the first time, a preliminary detection of a 3800K, 0.5 solar mass M dwarf companion in each of the long period (log[P(d)]=3), single-lined binaries WOCS 451 and WOCS 5671 in NGC 188. To assess the possibility of a false M dwarf detection, we carry out Monte Carlo simulations cross-correlating an M dwarf template with a BSS-only spectrum with a signal-to-noise ratio matching our observations. Theoretical detection limits for various BSS-M dwarf pairs are reported. In the case of a non-detection, such as in WOCS 4970, we are able to place an upper limit on the mass, and thus temperature, of the companion star. Current and future research goals aim for further insight into the BSS formation mechanism frequencies of NGC 188.
2006-07-04
KENNEDY SPACE CENTER, FLA. - Making history with the first-ever launch on Independence Day, Space Shuttle Discovery rockets into the blue sky on mission STS-121, trailing fiery exhaust and blue mach diamonds from the main engine nozzles. Liftoff was on-time at 2:38 p.m. EDT. During the 12-day mission, the STS-121 crew of seven will test new equipment and procedures to improve shuttle safety, as well as deliver supplies and make repairs to the International Space Station. Landing is scheduled for July 16 or 17 at Kennedy's Shuttle Landing Facility. Photo credit: NASA/Regina Mitchell-Ryall & Don Kight
2006-07-04
KENNEDY SPACE CENTER, FLA. - Making history with the first-ever launch on Independence Day, Space Shuttle Discovery rockets into the blue sky on mission STS-121, trailing fiery exhaust and blue mach diamonds from the main engine nozzles. Liftoff from Launch Pad 39B (seen below) was on-time at 2:38 p.m. EDT. During the 12-day mission, the STS-121 crew of seven will test new equipment and procedures to improve shuttle safety, as well as deliver supplies and make repairs to the International Space Station. Landing is scheduled for July 17 at Kennedy's Shuttle Landing Facility. Photo credit: NASA/Tony Gray & Tim Powers
2006-07-04
KENNEDY SPACE CENTER, FLA. - Making history with the first-ever launch on Independence Day, Space Shuttle Discovery rockets into the blue sky on mission STS-121, trailing fiery exhaust and blue mach diamonds from the main engine nozzles. Liftoff was on-time at 2:38 p.m. EDT. During the 12-day mission, the STS-121 crew of seven will test new equipment and procedures to improve shuttle safety, as well as deliver supplies and make repairs to the International Space Station. Landing is scheduled for July 16 or 17 at Kennedy's Shuttle Landing Facility. Photo credit: NASA/Regina Mitchell-Ryall & Don Kight
Lower-Dark-Current, Higher-Blue-Response CMOS Imagers
NASA Technical Reports Server (NTRS)
Pain, Bedabrata; Cunningham, Thomas; Hancock, Bruce
2008-01-01
Several improved designs for complementary metal oxide/semiconductor (CMOS) integrated-circuit image detectors have been developed, primarily to reduce dark currents (leakage currents) and secondarily to increase responses to blue light and increase signal-handling capacities, relative to those of prior CMOS imagers. The main conclusion that can be drawn from a study of the causes of dark currents in prior CMOS imagers is that dark currents could be reduced by relocating p/n junctions away from Si/SiO2 interfaces. In addition to reflecting this conclusion, the improved designs include several other features to counteract dark-current mechanisms and enhance performance.
Abou-Gamra, Z M; Ahmed, M A
2016-07-01
Herein, we demonstrate a facile route for synthesis a new photocatalyst based on TiO2-curcumin nanoparticles for photodegradation of methylene blue dye under UV and visible light irradiation. The photocatalyst was prepared by sol-gel method using chitosan as biodegradable polymer. The crystalline and the nanostructure were characteristic X-ray diffraction [XRD], adsorption-desorption isotherm and high resolution transmission electron microscopy [HRTEM]. However, the optical features of the samples were investigated by a UV-visible spectrophotometer. It is obvious to notice the removal of the majority of methylene blue dye on a pure titania surface via adsorption mechanism owing to the high surface area and to the organized mesoporous nature of the solid sample. Incorporation of curcumin on titania surface changes the removal direction from adsorption to the photocatalytic pathway. Various photocatalytic experiments were performed to investigate the influence of initial dye concentration, weight of catalyst, stirring and light intensity on the photocatalytic degradation of methylene blue as primary pollutant model. Chemical oxygen demand [COD] test confirms the complete degradation of methylene blue dye. The exceptional photocatalytic reactivity of titania-curcumin nanoparticles is referred to reduction in band gap energy and to the facility of electron transfer from II* curcumin energy level to titania conduction band which increases the concentration of reactive oxygen superoxide radicals which in turn prevents the electron-hole recombination. The effect of various scavengers on the methylene blue dye degradation was investigated using ethanol, ascorbic acid and methyl viologen. The results have pointed out that O2(-) and HO(.) are considered the main active species in the degradation process. A plausible pathway and mechanism for the photocatalytic degradation of methylene blue by titania-curcumin nanoparticles were illustrated. Copyright © 2016 Elsevier B.V. All rights reserved.
Wang, Ranran; Zimmerman, Julie
2016-05-17
As the fifth global water footprint assessment, this study enhanced previous estimates of national blue water consumption (including fresh surface and groundwater) and main economic activities with (1) improved spatial and sectoral resolution and (2) quantified the impacts of virtual water trade on water use and water stress at both the national and basin level. In 2007, 1194 Gm(3) of blue water was consumed globally for human purposes. The consuming (producing) of primary and manufactured goods and services from the sectors of "Primary Crops and Livestock", "Primary Energy and Minerals", "Processed Food and Beverages", "Non-food Manufactured Products", "Electricity", "Commercial and Public Services", and "Households" accounted for 33% (91%), ∼ 0% (1%), 37% (<1%), 13% (1%), 1% (2%), 15% (3%), and 2% (2%) of the world's total blue water consumption, respectively. The considerable differences in sectoral water consumption accounted for by the two perspectives (consumption- vs production-based) highlight the significance of the water consumed indirectly, upstream in the supply chain (i.e., > 70% of total blue water consumption) while offering additional insights into the water implications of critical interconnected economic activities, such as the water-energy nexus. With 145 Gm(3) (12%) of the blue water consumption embedded in the goods and services traded internationally, 89 countries analyzed were net blue water importers at the national level. On the basin level, the impacts of virtual water trade on water stress were statistically significant for basins across the world and within 104 countries; virtual water trade mitigated water stress for the basins within 85 of the 104 countries, including all of those where there are moderate and greater water stress countrywide (except Italy).
Brelsford, Craig C; Morales, Luis O; Nezval, Jakub; Kotilainen, Titta K; Hartikainen, Saara M; Aphalo, Pedro J; Robson, T Matthew
2018-04-28
We studied how plants acclimated to growing conditions that included combinations of blue light and ultraviolet-A (UV-A) radiation, and whether their growing environment affected their photosynthetic capacity during and after a brief period of acute high light (as might happen during an under-canopy sunfleck). Arabidopsis thaliana Landsberg erecta wild-type were compared with mutants lacking functional blue-light-and-UV photoreceptors: phototropin 1PHOT1, cryptochromes (CRY1 and CRY2) and UV RESISTANT LOCUS 8 (uvr8). This was achieved using LED lamps in a controlled environment to create treatments with or without blue light, in a split-plot design with or without UV-A radiation. We compared the accumulation of phenolic compounds under growth conditions and after exposure to 30 minutes of high light at the end of the experiment (46 days), and likewise measured the operational efficiency of photosystem II (φPSII a proxy for photosynthetic performance) and dark-adapted maximum quantum yield (F v /F m to assess PSII damage). Our results indicate that cryptochromes are the main photoreceptors regulating phenolic-compound accumulation in response to blue light and UV-A radiation, and a lack of functional cryptochromes impairs photosynthetic performance under high light. Our findings also reveal a role for UVR8 in accumulating flavonoids in response to a low UV-A dose. Interestingly, phototropin 1 partially-mediated constitutive accumulation of phenolic compounds in the absence of blue light. Low irradiance blue light and UV-A did not improve φPSII and F v /F m upon our acute high light treatment, however CRYs played an important role in ameliorating high-light stress. This article is protected by copyright. All rights reserved.
Suhayda, C G; Omura, M; Hasegawa, S
1995-09-01
Bitter limonoids in citrus juice lower the quality and value of commercial juices. Limonoate dehydrogenase converts the precursor of bitter limonin, limonoate A-ring lactone, to nonbitter 17-dehydrolimonoate A-ring lactone. This enzyme was isolated from Arthrobacter globiformis cells by a combination of ammonium sulfate fractionation, Cibacron Blue affinity chromatography and DEAE ion exchange HPLC. Using this protocol a 428-fold purification of the enzyme was obtained. Gel filtration HPLC indicated a M(r) of 118,000 for the native enzyme. SDS-PAGE indicated an individual subunit M(r) of 31,000. N-Terminal sequencing of the protein provided a sequence of the first 16 amino acid residues. Since LDH activity in citrus is very low, cloning the gene for this bacterial enzyme into citrus trees should enhance the natural debittering mechanism in citrus fruit.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Genzel, R.; Tacconi, L. J.; Kurk, J.
We report matched resolution imaging spectroscopy of the CO 3-2 line (with the IRAM Plateau de Bure millimeter interferometer) and of the H{alpha} line (with LUCI at the Large Binocular Telescope) in the massive z = 1.53 main-sequence galaxy EGS 13011166, as part of the ''Plateau de Bure high-z, blue-sequence survey'' (PHIBSS: Tacconi et al.). We combine these data with Hubble Space Telescope V-I-J-H-band maps to derive spatially resolved distributions of stellar surface density, star formation rate, molecular gas surface density, optical extinction, and gas kinematics. The spatial distribution and kinematics of the ionized and molecular gas are remarkably similarmore » and are well modeled by a turbulent, globally Toomre unstable, rotating disk. The stellar surface density distribution is smoother than the clumpy rest-frame UV/optical light distribution and peaks in an obscured, star-forming massive bulge near the dynamical center. The molecular gas surface density and the effective optical screen extinction track each other and are well modeled by a ''mixed'' extinction model. The inferred slope of the spatially resolved molecular gas to star formation rate relation, N = dlog{Sigma}{sub starform}/dlog{Sigma}{sub molgas}, depends strongly on the adopted extinction model, and can vary from 0.8 to 1.7. For the preferred mixed dust-gas model, we find N = 1.14 {+-} 0.1.« less
Stepanyuk, Galina A.; Xu, Hao; Wu, Chia-Kuei; Markova, Svetlana V.; Lee, John; Vysotski, Eugene S.; Wang, Bi-Cheng
2008-01-01
Metridia luciferase is a secreted luciferase from a marine copepod and uses coelenterazine as a substrate to produce a blue bioluminescence (λmax = 480 nm). This luciferase has been successfully applied as a bioluminescent reporter in mammalian cells. The main advantage of secreted luciferase as a reporter is the capability of measuring intracellular events without destroying the cells or tissues and this property is well suited for development of high throughput screening technologies. However because Metridia luciferase is a Cys-rich protein, E. coli expression systems produce an incorrectly folded protein, hindering its biochemical characterization and application for development of in vitro bioluminescent assays. Here we report the successful expression of Metridia luciferase with its signal peptide for secretion, in insect (Sf9) cells using the baculovirus expression system. Functionally active luciferase secreted by insect cells into the culture media has been efficiently purified with a yield of high purity protein of 2–3 mg/L. This Metridia luciferase expressed in the insect cell system is a monomeric protein showing 3.5-fold greater bioluminescence activity than luciferase expressed and purified from E. coli. The near coincidence of the experimental mass of Metridia luciferase purified from insect cells with that calculated from amino acid sequence, indicates that luciferase does not undergo posttranslational modifications such as phosphorylation or glycosylation and also, the cleavage site of the signal peptide for secretion is at VQA-KS, as predicted from sequence analysis. PMID:18595733
Sun, Steven; Francis, Jesse; Sapsford, Kim E.; Kostov, Yordan; Rasooly, Avraham
2010-01-01
A portable and rapid detection system for the activity analysis of Botulinum Neurotoxins (BoNT) is needed for food safety and bio-security applications. To improve BoNT activity detection, a previously designed portable charge-coupled device (CCD) based detector was modified and equipped with a higher intensity more versatile multi-wavelength spatial light-emitting diode (LED) illumination, a faster CCD detector and the capability to simultaneously detect 30 samples. A FITC/DABCYL Förster Resonance Energy Transfer (FRET)-labeled peptide substrate (SNAP-25), with BoNT-A target cleavage site sequence was used to measure BoNT-A light chain (LcA) activity through the FITC fluorescence increase that occurs upon peptide substrate cleavage. For fluorescence excitation, a multi-wavelength spatial LED illuminator was used and compared to our previous electroluminescent (EL) strips. The LED illuminator was equipped with blue, green, red and white LEDs, covering a spectrum of 450-680 nm (red 610-650 nm, green 492-550 nm, blue 450-495 nm, and white LED 440-680 nm). In terms of light intensity, the blue LED was found to be ~80 fold higher than the previously used blue EL strips. When measuring the activity of LcA the CCD detector limit of detection (LOD) was found to be 0.08 nM LcA for both the blue LED (2 s exposure) and the blue EL (which require ≥60 s exposure) while the limits of quantitation (LOQ) is about 1 nM. The LOD for white LED was higher at 1.4 nM while the white EL was not used for the assay due to a high variable background. Unlike the weaker intensity EL illumination the high intensity LED illumination enabled shorter exposure times and allowed multi-wavelength illumination without the need to physically change the excitation strip, thus making spectrum excitation of multiple fluorophores possible increasing the versatility of the detector platform for a variety of optical detection assays. PMID:20498728
Sugimoto, Yuki; Nakamura, Hiroshi; Ren, Shukun; Hori, Koichi; Masuda, Shinji
2017-03-01
The Synechocystis sp. PCC6803 can move on a solid surface in response to light, a phenomenon called phototaxis. Although many of the photoreceptors involved in phototaxis have been identified, the mechanisms that regulate directional motility of Synechocystis are not well understood. Previous studies showed that a mutant lacking the blue light-using flavin (BLUF) photoreceptor PixD exhibits negative phototaxis under conditions where the wild type responds positively. PixD interacts with the pseudo-response regulator-like protein PixE in a light-dependent manner, suggesting that this intermolecular interaction is important for phototaxis regulation, although genetic evidence has been lacking. To gain further insight into phototaxis regulation by PixD-PixE signaling, we constructed the deletion mutants ΔPixE and ΔPixD-ΔPixE, and characterized their phenotypes, which matched those of the wild type (positive phototaxis). Because ΔPixD exhibited negative phototaxis, PixE must function downstream of PixD. Under intense blue light (>100 μmol m-2 s-1; 470 nm) the wild type exhibited negative phototaxis, but ΔPixD-PixE exhibited positive phototaxis toward low-intensity blue light (∼0.8 μmol m-2 s-1; 470 nm). These results suggest that an unknown light-sensing system(s), that is necessary for directional cell movement, can be activated by low-intensity blue light; on the other hand, PixD needs high-intensity blue light to be activated. We also isolated spontaneous mutants that compensated for the pixE deletion. Genome-wide sequencing of the mutants revealed that the uncharacterized gene sll2003 regulates positive and negative phototaxis in response to light intensity. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Atmospheric Science Data Center
2013-04-18
... Arequipa, provide a striking demonstration of the power of water erosion. This image pair was acquired by the Multi-angle Imaging ... stereo image in 3-D requires red/blue glasses with the red filter placed over your left eye. Two main erosion formations can be seen. ...
NASA Astrophysics Data System (ADS)
Ruan, Jiufeng; Yang, Zhengwen; Huang, Anjun; Chai, Zhuangzhuang; Qiu, Jianbei; Song, Zhiguo
2018-01-01
Blue light converted light-emitting diodes is of great significance as a candidate for next generation lighting. In this work, the WO3:Eu3+ inverse opal photonic crystals were prepared and their luminescence properties were studied. The results demonstrated that the main excitation peak of WO3:Eu3+ inverse opals were located at 465 nm. The red luminescence peak at the 613 nm was observed in the WO3:Eu3+ inverse opal upon 465 nm excitation, exhibiting better red color purity. The influence of photonic band gap on the photoluminescence of WO3:Eu3+ inverse opal was obtained. When the red luminescence peak is in the regions of the photonic band gap and the edge of the band-gap, the red luminescence suppression and enhancement was observed respectively. The WO3:Eu3+ inverse opals may be a promising candidate for the blue light converted LEDs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kotani, Teruhisa, E-mail: tkotani@iis.u-tokyo.ac.jp; Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505; Advanced Technology Research Laboratories, Sharp Corporation, 2613-1 Ichinomoto-cho, Tenri, Nara 632-8567
2015-09-14
Blue shift and broadening of the absorption spectra of mid-infrared intersubband transition in non-polar m-plane AlGaN/GaN 10 quantum wells were observed with increasing doping density. As the doping density was increased from 6.6 × 10{sup 11} to 6.0 × 10{sup 12 }cm{sup −2} per a quantum well, the intersubband absorption peak energy shifted from 274.0 meV to 302.9 meV, and the full width at half maximum increased from 56.4 meV to 112.4 meV. Theoretical calculations reveal that the blue shift is due to many body effects, and the intersubband linewidth in doped AlGaN/GaN QW is mainly determined by scattering due to interface roughness, LO phonons, and ionized impurities.
Quantitative Study of Blue Stars in NGC 55
NASA Astrophysics Data System (ADS)
Castro, N.; Herrero, A.; Urbaneja, M. A.; García, M.; Simón-Díaz, S.; Bresolin, F.; Pietrzynski, G.; Kudritzki, R.-P.; Gieren, W.
2012-12-01
Massive blue stars are the rarest in number compared with other stars; however, they are the main engines in the chemical and dynamical evolution of galaxies in the Universe. They are also among the brightest stars, making it possible to be observed (and hence studied) beyond the edges of the Milky Way. In the case of the galaxy NGC 55 (1.9 Mpc), presented in this work, it has been not only possible to provide the first census of massive blue stars, but also perform a fully characterization of these stars, including the stellar parameters, the chemical abundances, and information about their evolutionary stages. Even so, that permitted to derive important properties of the host galaxy. This challenging study is based on an objective and fast automatic technique built upon a new state-of-the-art FASTWIND atmosphere model grid. Both the tool and the grid were specially developed for this project.
Cruz-Flores, Roberto; Cáceres-Martínez, Jorge; Muñoz-Flores, Monserrat; Vásquez-Yeomans, Rebeca; Hernández Rodriguez, Mónica; Ángel Del Río-Portilla, Miguel; Rocha-Olivares, Axayácatl; Castro-Longoria, Ernestina
2016-10-01
Candidatus Xenohaliotis californiensis (CXc) is a Rickettsiales-like prokaryote that is considered the causal agent of Withering Syndrome (WS), a chronic disease of abalone, from the west coast of North America and it is listed by the International Organization for Animal Health (OIE) as a reportable agent due to its pathogenicity. This bacterium in red abalone Haliotis rufescens, black abalone Haliotis cracherodii, and yellow abalone Haliotis corrugata from California, US and Baja California, Mexico has been found to be infected by a bacteriophage. To date, there is no information on the epizootiology of CXc and its bacteriophage in natural populations of abalone; furthermore, it is unknown if the bacteriophage was also present in CXc infecting blue abalone Haliotis fulgens. The objective of this study was to determine the distribution, prevalence and intensity of CXc, as well as to determine the distribution and prevalence of the bacteriophage and to study interactions between host sex and hyperparasitism in blue abalone and yellow abalone. Tissue samples were obtained from seven localities where the commercial capture of wild abalone is carried out. Samplings were conducted throughout the 2012-2013 capture seasons and a total of 182 blue abalone and 170 yellow abalone were obtained. The prevalence and intensity of CXc and the prevalence of the bacteriophage were determined by histology. The identity of CXc was confirmed by PCR, product sequence analysis and in situ hybridization while the identity of the bacteriophage was corroborated by TEM. The prevalence of CXc infected and uninfected by the bacteriophage was 80% in blue abalone and 62% in yellow abalone. Low infection intensities were found in 86% of blue abalone and 82% of yellow abalone. Infection intensity was significantly higher in undifferentiated yellow abalone. The bacteriophage in CXc showed a prevalence of 22% and 31% in blue abalone and yellow abalone respectively. These results show that CXc and its bacteriophage are widely distributed in the peninsula of Baja California and that they are well established in natural populations of blue abalone and yellow abalone. Additionally, this data constitutes the first record of a bacteriophage in blue abalone. Copyright © 2016 Elsevier Inc. All rights reserved.
Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan
2014-01-01
Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.
NASA Astrophysics Data System (ADS)
Marziani, Paola; Sulentic, J. W.; Dultzin, D.; Negrete, A.; del Olmo, A.; Martínez-Carballo, M. A.; Stirpe, G. M.; D'Onofrio, M.; Perea, J.
2016-10-01
The 4D eigenvector 1 parameter space defined by Sulentic et al. may be seen as a surrogate H-R diagram for quasars. As in the stellar H-R diagram, a source sequence can be easily identified. In the case of quasars, the main sequence appears to be mainly driven by Eddington ratio. A transition Eddington ratio may in part explain the striking observational differences between quasars at opposite ends of the main sequence. The eigenvector-1 approach opens the door towards properly contextualized models of quasar physics, geometry and kinematics. We review some of the progress that has been made over the past 15 years, and point out still unsolved issues.
A genosensor for detection of consensus DNA sequence of Dengue virus using ZnO/Pt-Pd nanocomposites.
Singhal, Chaitali; Pundir, C S; Narang, Jagriti
2017-11-15
An electrochemical genosensor based on Zinc oxide/platinum-palladium (ZnO/Pt-Pd) modified fluorine doped tin oxide (FTO) glass plate was fabricated for detection of consensus DNA sequence of Dengue virus (DENV) using methylene blue (MB) as an intercalating agent. To achieve it, probe DNA (PDNA) was immobilized on the surface of ZnO/Pt-Pd nanocomposites modified FTO electrode. The synthesized nano-composites were characterized by high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM), scanning electron microscopy (SEM), UV-Vis spectroscopy, X-ray diffraction (XRD) analysis and Fourier transform infra-red (FTIR) spectroscopy. This PDNA modified electrode (PDNA/ZnO/Pt-Pd/FTO) served as a signal amplification platform for the detection of the target hybridized DNA (TDNA). The hybridization between PDNA and TDNA was detected by reduction in current, generated by interaction of anionic mediator, i.e., methylene blue (MB) with free guanine (3'G) of ssDNA. The sensor showed a dynamic linear range of 1 × 10 -6 M to 100 × 10 -6 M with LOD as 4.3 × 10 -5 M and LOQ as 9.5 × 10 -5 M. Till date, majorly serotype specific biosensors for dengue detection have been developed. The genosensor reported here eliminates the possibility of false result as in case of serotype specific DNA sensor. This is the report where conserved sequences present in all the serotypes of Dengue virus has been employed for fabrication of a genosensor. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Rahi, Amid; Sattarahmady, Naghmeh; Heli, Hossein
2015-12-01
Gold nanoribbons covered by gold nanoblooms were sonoelectrodeposited on a polycrystalline gold surface at -1800 mV (vs. AgCl) with the assistance of ultrasound and co-occurrence of the hydrogen evolution reaction. The nanostructure, as a transducer, was utilized to immobilize a Brucella-specific probe and fabrication of a genosensor, and the process of immobilization and hybridization was detected by electrochemical methods, using methylene blue as a redox marker. The proposed method for detection of the complementary sequence, sequences with base-mismatched (one-, two- and three-base mismatches), and the sequence of non-complementary sequence was assayed. The fabricated genosensor was evaluated for the assay of the bacteria in the cultured and human samples without polymerase chain reactions (PCR). The genosensor could detect the complementary sequence with a calibration sensitivity of 0.40 μA dm3 mol-1, a linear concentration range of 10 zmol dm-3 to 10 pmol dm-3, and a detection limit of 1.71 zmol dm-3.
The Red Spiral Galaxy UGC11680: Clues for the Inside-Out Quenching.
NASA Astrophysics Data System (ADS)
Bárcenas, J.; Sanchez, S. F.
2016-06-01
Broadly, galaxies can be divided in two groups, thanks to the Color-Magnitude Diagram: the lively star formation ones, ``The blue Cloud'' and galaxies which halted their star formation, ``The Red Sequence''. It is a currently accepted that the galaxies start their lifespan as a blue objects, turning red when they stop to assembly more mass and thus more stars. Nevertheless, This change need to be quick (˜ 1 Gyr), due to the dearth of galaxies between this two populations (the so called ``green valley'').Previous works have found two distinct stellar mass assembly modes, they are termed as ``the inside-out'' and ``the outside-in'' growth scenarios in the literature. In the ``inside-out'' scenario, mass assembly is finished in the galactic central region. In some cases, the inflow gas can fuel the central SuperMassive BlackHole. The subsequent AGN feedback will then shut-off the central star formation. One possible case of this scenario is the galaxy UGC11680, an unusual face-on red spiral galaxy with an AGN type 2, at the red sequence belonging to the CALIFA survey. We used the so called fossil method to study its star formation history and try to understand what happened to its stellar populations.
Silva, TF; Corrêa, RL; Castilho, Y; Silvie, P; Bélot, J-L; Vaslin, MFS
2008-01-01
Background Cotton blue disease (CBD), an important global cotton crop pathology responsible for major economic losses, is prevalent in the major cotton-producing states of Brazil. Typical CBD symptoms include stunting due to internodal shortening, leaf rolling, intense green foliage, and yellowing veins. Atypical CBD symptoms, including reddish and withered leaves, were also observed in Brazilian cotton fields in 2007. Recently, a Polerovirus named Cotton leafroll dwarf virus (CLRDV) was shown to be associated with CBD. Results To understand the distribution and genetic diversity of CLRDV in Brazil, we analyzed 23 CBD-symptomatic plants from susceptible cotton varieties originating from five of the six most important cotton-growing states, from 2004–2007. Here, we report on CLRDV diversity in plants with typical or atypical CBD symptoms by comparing viral coat protein, RNA polymerase (RdRp), and intergenic region genomic sequences. Conclusion The virus had a widespread distribution with a low genetic diversity; however, three divergent isolates were associated with atypical CBD symptoms. These divergent isolates had a CLRDV-related coat protein but a distinct RdRp sequence, and probably arose from recombination events. Based on the taxonomic rules for the family Luteoviridae, we propose that these three isolates represent isolates of a new species in the genus Polerovirus. PMID:18937850
Silva, T F; Corrêa, R L; Castilho, Y; Silvie, P; Bélot, J-L; Vaslin, M F S
2008-10-20
Cotton blue disease (CBD), an important global cotton crop pathology responsible for major economic losses, is prevalent in the major cotton-producing states of Brazil. Typical CBD symptoms include stunting due to internodal shortening, leaf rolling, intense green foliage, and yellowing veins. Atypical CBD symptoms, including reddish and withered leaves, were also observed in Brazilian cotton fields in 2007. Recently, a Polerovirus named Cotton leafroll dwarf virus (CLRDV) was shown to be associated with CBD. To understand the distribution and genetic diversity of CLRDV in Brazil, we analyzed 23 CBD-symptomatic plants from susceptible cotton varieties originating from five of the six most important cotton-growing states, from 2004-2007. Here, we report on CLRDV diversity in plants with typical or atypical CBD symptoms by comparing viral coat protein, RNA polymerase (RdRp), and intergenic region genomic sequences. The virus had a widespread distribution with a low genetic diversity; however, three divergent isolates were associated with atypical CBD symptoms. These divergent isolates had a CLRDV-related coat protein but a distinct RdRp sequence, and probably arose from recombination events. Based on the taxonomic rules for the family Luteoviridae, we propose that these three isolates represent isolates of a new species in the genus Polerovirus.
Blue straggler formation at core collapse
NASA Astrophysics Data System (ADS)
Banerjee, Sambaran
Among the most striking feature of blue straggler stars (BSS) in globular clusters is the presence of multiple sequences of BSSs in the colour-magnitude diagrams (CMDs) of several globular clusters. It is often envisaged that such a multiple BSS sequence would arise due a recent core collapse of the host cluster, triggering a number of stellar collisions and binary mass transfers simultaneously over a brief episode of time. Here we examine this scenario using direct N-body computations of moderately-massive star clusters (of order 104 {M⊙). As a preliminary attempt, these models are initiated with ≈8-10 Gyr old stellar population and King profiles of high concentrations, being ``tuned'' to undergo core collapse quickly. BSSs are indeed found to form in a ``burst'' at the onset of the core collapse and several of such BS-bursts occur during the post-core-collapse phase. In those models that include a few percent primordial binaries, both collisional and binary BSSs form after the onset of the (near) core-collapse. However, there is as such no clear discrimination between the two types of BSSs in the corresponding computed CMDs. We note that this may be due to the less number of BSSs formed in these less massive models than that in actual globular clusters.
Kühne, Gero; Kosuch, Joachim; Hochkirch, Axel; Schmitt, Thomas
2017-01-01
Most warm-adapted Central European species are thought to have survived ice ages exclusively in Mediterranean refugia. During recent years, this point of view has been questioned. Therefore, we tested the hypothesis that extra-Mediterranean refugia also played a role in warm-adapted insect species and selected the chalk-hill blue, Polyommatus coridon. We sequenced two mitochondrial loci (COI, CR) in 150 individuals from 30 populations covering nearly the complete range. Minimum spanning networks and other statistical analyses concordantly revealed four genetic lineages with strong phylogeographic signal: a western group in Italy, France and western/central Germany, an eastern lineage in the Balkan Peninsula, the Carpathian Basin and eastern Central Europe, an Alpine group with populations in the Alps and southern Germany and a Pyrenean group. Our results are generally consistent with previous analyses for P. coridon based on allozymes and DNA sequences, but provide additional insights. We propose that these four lineages have evolved during allopatry in different glacial refugia, two in typical Mediterranean refugia (Apennines and Balkan Peninsulas), but two in extra-Mediterranean areas south of the Alps and Pyrenees. This supports survival of warm-adapted organisms in these regions in close geographic proximity to the refugia of high mountain species.
NASA Astrophysics Data System (ADS)
Gong, Liang; Wu, Yu; Jian, Qijie; Yin, Chunxiao; Li, Taotao; Gupta, Vijai Kumar; Duan, Xuewu; Jiang, Yueming
2018-01-01
Vibrio qinghaiensis sp.-Q67 (Vqin-Q67) is a freshwater luminescent bacterium that continuously emits blue-green light (485 nm). The bacterium has been widely used for detecting toxic contaminants. Here, we report the complete genome sequence of Vqin-Q67, obtained using third-generation PacBio sequencing technology. Continuous long reads were attained from three PacBio sequencing runs and reads >500 bp with a quality value of >0.75 were merged together into a single dataset. This resultant highly-contiguous de novo assembly has no genome gaps, and comprises two chromosomes with substantial genetic information, including protein-coding genes, non-coding RNA, transposon and gene islands. Our dataset can be useful as a comparative genome for evolution and speciation studies, as well as for the analysis of protein-coding gene families, the pathogenicity of different Vibrio species in fish, the evolution of non-coding RNA and transposon, and the regulation of gene expression in relation to the bioluminescence of Vqin-Q67.
pYEMF, a pUC18-derived XcmI T-vector for efficient cloning of PCR products.
Gu, Jingsong; Ye, Chunjiang
2011-03-01
A 1330-bp DNA sequence with two XcmI cassettes was inserted into pUC18 to construct an efficient XcmI T-vector parent plasmid, pYEMF. The large size of the inserted DNA fragment improved T-vector cleavage efficiency, and guaranteed good separation of the molecular components after restriction digestion. The pYEMF-T-vector generated from parent plasmid pYEMF permits blue/white colony screening; cloning efficiency analysis showed that most white colonies (>75%) were putative transformants which carried the cloning product. The sequence analysis and design approach presented here will facilitate applications in the fields of molecular biology and genetic engineering.
Evolution of the rhodospirillaceae and mitochondria - A view based on sequence data
NASA Technical Reports Server (NTRS)
Dayhoff, M. O.; Schwartz, R. M.
1981-01-01
New sequence data from several protein families and from 5S ribosomal RNA confirm and elaborate a previously proposed description of the phylogenetic connections between a variety of bacteria and the eukaryotes. Probably, the first organisms were nonphotosynthetic anaerobic prokaryotes, which were followed soon by photosynthetic anaerobes. From this photosynthetic stock, the aerobic line to Pseudomonadacae, Rhodospirillaceae, and blue-greens arose. The eukaryotes derived genetic material from the symbioses of at least three separate bacterial lines. Ancestors of Rhodopseudomonas globiformis gave rise to the eukaryote mitochondria, probably through at least three separate symbioses, one early on the flagellate line, one on the ciliate line, and one on the stem to the multicellular forms.
Wehmeier, U F
1995-11-07
Four new shuttle vectors for Escherichia coli (Ec) and Streptomyces, pUWL218, pUWL219, pUWL-SK and pUWL-KS, which permit recognition of recombinant (re-) plasmids on XGal plates in Ec, were constructed. These vectors contain the replication functions of the Streptomyces wide-host-range multicopy plasmid pIJ101, the tsr gene conferring resistance to thiostrepton in Streptomyces, the ColEI origin of replication from the pUC plasmids for replication in Ec and the bla gene conferring resistance to ampicillin in Ec. They possess multiple cloning sites with a number of unique restriction sites and allow direct sequencing of re-derivatives using the pUC sequencing primers.
Life on an Island: Early Settlers off the Rock Bound Coast of Maine. Teaching with Historic Places.
ERIC Educational Resources Information Center
Hobbs-Olson, Laurie
This lesson, based on National Register of Historic Places files, describes early settlers' lives on some of the approximately 5,000 islands off the coast of Maine. During the mid-18th century many of these islands began to be inhabited by settlers eager to take advantage of this interface between land and sea. The lesson discusses the Blue Duck…
Systems Engineering Approach for Conceptual Design of Frigate
2015-09-01
ejection area. Topside designers should also take note of the gun maintenance required area (e.g., barrel swabbing area), which requires significant...Figure 9. Range-to-Target Plot (BlueIntercept Missile vs. RedFire) ........................34 Figure 10. Range-to-Target Plot (Main Gun System vs...and the secondary anti-air weapon will be the main gun system. The frigates shall also be equipped with an area terminal type defense (ATTD
NASA Astrophysics Data System (ADS)
Tofflemire, Benjamin M.; Mathieu, Robert D.; Ardila, David R.; Ciardi, David R.
2015-01-01
Most stars are born in binaries, and the evolution of protostellar disks in pre-main sequence (PMS) binary stars is a current frontier of star formation research. PMS binary stars can have up to three accretion disks: two circumstellar disks and a circumbinary disk separated by a dynamically cleared gap. Theory suggests that mass may periodically flow in an accretion stream from a circumbinary disk across the gap onto circumstellar disks or stellar surfaces. Thus, accretion in PMS binaries is controlled by not only radiation, disk viscosity, and magnetic fields, but also by orbital dynamics.As part of a larger, ongoing effort to characterize mass accretion in young binary systems, we test the predictions of the binary accretion stream theory through continuous, multi-orbit, multi-color optical and near-infrared (NIR) time-series photometry. Observations such as these are capable of detecting and characterizing these modulated accretion streams, if they are generally present. Broad-band blue and ultraviolet photometry trace the accretion luminosity and photospheric temperature while NIR photometry provide a measurement of warm circumstellar material, all as a function of orbital phase. The predicted phase and magnitude of enhanced accretion are highly dependent on the binary orbital parameters and as such, our campaign focuses on 10 PMS binaries of varying periods and eccentricities. Here we present multi-color optical (U, B,V, R), narrowband (Hα), and multi-color NIR (J, H) lightcurves of the PMS binary V4046 Sgr (P=2.42 days) obtained with the SMARTS 1.3m telescope and LCOGT 1m telescope network. These results act to showcase the quality and breadth of data we have, or are currently obtaining, for each of the PMS binaries in our sample. With the full characterization of our sample, these observations will guide an extension of the accretion paradigm from single young stars to multiple systems.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sharma, Ms. Ketki; Kim, Yong-Ha; Yiacoumi, Sotira
The mixing process of fresh water and seawater releases a significant amount of energy and is a potential source of renewable energy. The so called ‘blue energy’ or salinity-gradient energy can be harvested by a device consisting of carbon electrodes immersed in an electrolyte solution, based on the principle of capacitive double layer expansion (CDLE). In this study, we have investigated the feasibility of energy production based on the CDLE principle. Experiments and computer simulations were used to study the process. Mesoporous carbon materials, synthesized at the Oak Ridge National Laboratory, were used as electrode materials in the experiments. Neutronmore » imaging of the blue energy cycle was conducted with cylindrical mesoporous carbon electrodes and 0.5 M lithium chloride as the electrolyte solution. For experiments conducted at 0.6 V and 0.9 V applied potential, a voltage increase of 0.061 V and 0.054 V was observed, respectively. From sequences of neutron images obtained for each step of the blue energy cycle, information on the direction and magnitude of lithium ion transport was obtained. A computer code was developed to simulate the process. Experimental data and computer simulations allowed us to predict energy production.« less
Baleen whale infrasonic sounds: Natural variability and function
NASA Astrophysics Data System (ADS)
Clark, Christopher W.
2004-05-01
Blue and fin whales (Balaenoptera musculus and B. physalus) produce very intense, long, patterned sequences of infrasonic sounds. The acoustic characteristics of these sounds suggest strong selection for signals optimized for very long-range propagation in the deep ocean as first hypothesized by Payne and Webb in 1971. This hypothesis has been partially validated by very long-range detections using hydrophone arrays in deep water. Humpback songs recorded in deep water contain units in the 20-l00 Hz range, and these relatively simple song components are detectable out to many hundreds of miles. The mid-winter peak in the occurrence of 20-Hz fin whale sounds led Watkins to hypothesize a reproductive function similar to humpback (Megaptera novaeangliae) song, and by default this function has been extended to blue whale songs. More recent evidence shows that blue and fin whales produce infrasonic calls in high latitudes during the feeding season, and that singing is associated with areas of high productivity where females congregate to feed. Acoustic sampling over broad spatial and temporal scales for baleen species is revealing higher geographic and seasonal variability in the low-frequency vocal behaviors than previously reported, suggesting that present explanations for baleen whale sounds are too simplistic.
Odour-based discrimination of similarity at the major histocompatibility complex in birds
Strandh, Maria; Mardon, Jérôme; Westerdahl, Helena; Bonadonna, Francesco
2017-01-01
Many animals are known to preferentially mate with partners that are dissimilar at the major histocompatibility complex (MHC) in order to maximize the antigen binding repertoire (or disease resistance) in their offspring. Although several mammals, fish or lizards use odour cues to assess MHC similarity with potential partners, the ability of birds to assess MHC similarity using olfactory cues has not yet been explored. Here we used a behavioural binary choice test and high-throughput-sequencing of MHC class IIB to determine whether blue petrels can discriminate MHC similarity based on odour cues alone. Blue petrels are seabirds with particularly good sense of smell, they have a reciprocal mate choice and are known to preferentially mate with MHC-dissimilar partners. Incubating males preferentially approached the odour of the more MHC-dissimilar female, whereas incubating females showed opposite preferences. Given their mating pattern, females were, however, expected to show preference for the odour of the more MHC-dissimilar male. Further studies are needed to determine whether, as in women and female mice, the preference varies with the reproductive cycle in blue petrel females. Our results provide the first evidence that birds can use odour cues only to assess MHC dissimilarity. PMID:28077776
Sati, Leyla; Huszar, Gabor
2013-01-01
In this chapter, the laboratory methods for detection of sperm biomarkers that are aimed at identifying arrested sperm development are summarized. These probes include sperm staining with aniline blue for persistent histones, representing a break in the histone-transition protein-protamine sequence, immunocytochemistry with cytoplasmic sperm proteins, highlighting cytoplasmic retention during spermiogenesis, DNA nick translation testing for DNA chain fragmentation due to various reasons, for instance low HspA2 chaperone protein levels, and consequential diminished DNA repair. Finally, we briefly provide references on our work on sperm hyaluronan binding, abnormal Tybergerg sperm morphology, and the increased levels of chromosomal aneuploidies in sperm with developmental arrest. A very interesting aspect of the biomarker field is the discovery (Sati et al, Reprod Biomed Online 16:570-579, 2008) that the various nuclear and cytoplasmic defects detected by the biomarkers are related, and may simultaneously occur within the same spermatozoa as evidenced by a combination of biomarkers, such as aniline blue staining (persistent histones) coupled with cytoplasmic retention, DNA fragmentation, Caspase-3, Tygerberg abnormal morphology, and increased levels of chromosomal aneuploidies. We show examples of this >80% overlap in staining patterns within the same spermatozoa.
2014-01-01
Background Blue light is a high-energy or short-wavelength visible light, which induces retinal diseases such as age-related macular degeneration and retinitis pigmentosa. Bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea) contain high amounts of polyphenols (anthocyanins, resveratrol, and proanthocyanidins) and thus confer health benefits. This study aimed to determine the protective effects and mechanism of action of bilberry extract (B-ext) and lingonberry extract (L-ext) and their active components against blue light-emitting diode (LED) light-induced retinal photoreceptor cell damage. Methods Cultured murine photoreceptor (661 W) cells were exposed to blue LED light following treatment with B-ext, L-ext, or their constituents (cyanidin, delphinidin, malvidin, trans-resveratrol, and procyanidin B2). 661 W cell viability was assessed using a tetrazolium salt (WST-8) assay and Hoechst 33342 nuclear staining, and intracellular reactive oxygen species (ROS) production was determined using CM-H2DCFDA after blue LED light exposure. Activation of p38 mitogen-activated protein kinase (p38 MAPK), nuclear factor-kappa B (NF-κB), and LC3, an ubiquitin-like protein that is necessary for the formation of autophagosomes, were analyzed using Western blotting. Caspase-3/7 activation caused by blue LED light exposure in 661 W cells was determined using a caspase-3/7 assay kit. Results B-ext, L-ext, NAC, and their active components improved the viability of 661 W cells and inhibited the generation of intracellular ROS induced by blue LED light irradiation. Furthermore, B-ext and L-ext inhibited the activation of p38 MAPK and NF-κB induced by blue LED light exposure. Finally, B-ext, L-ext, and NAC inhibited caspase-3/7 activation and autophagy. Conclusions These findings suggest that B-ext and L-ext containing high amounts of polyphenols exert protective effects against blue LED light-induced retinal photoreceptor cell damage mainly through inhibition of ROS production and activation of pro-apoptotic proteins. PMID:24690313
Siipola, Sari M; Kotilainen, Titta; Sipari, Nina; Morales, Luis O; Lindfors, Anders V; Robson, T Matthew; Aphalo, Pedro J
2015-05-01
Plants synthesize phenolic compounds in response to certain environmental signals or stresses. One large group of phenolics, flavonoids, is considered particularly responsive to ultraviolet (UV) radiation. However, here we demonstrate that solar blue light stimulates flavonoid biosynthesis in the absence of UV-A and UV-B radiation. We grew pea plants (Pisum sativum cv. Meteor) outdoors, in Finland during the summer, under five types of filters differing in their spectral transmittance. These filters were used to (1) attenuate UV-B; (2) attenuate UV-B and UV-A < 370 nm; (3) attenuate UV-B and UV-A; (4) attenuate UV-B, UV-A and blue light; and (5) as a control not attenuating these wavebands. Attenuation of blue light significantly reduced the flavonoid content in leaf adaxial epidermis and reduced the whole-leaf concentrations of quercetin derivatives relative to kaempferol derivatives. In contrast, UV-B responses were not significant. These results show that pea plants regulate epidermal UV-A absorbance and accumulation of individual flavonoids by perceiving complex radiation signals that extend into the visible region of the solar spectrum. Furthermore, solar blue light instead of solar UV-B radiation can be the main regulator of phenolic compound accumulation in plants that germinate and develop outdoors. © 2014 John Wiley & Sons Ltd.
Leroy, Emmanuelle C; Samaran, Flore; Bonnel, Julien; Royer, Jean-Yves
2016-01-01
Passive acoustic monitoring is an efficient way to provide insights on the ecology of large whales. This approach allows for long-term and species-specific monitoring over large areas. In this study, we examined six years (2010 to 2015) of continuous acoustic recordings at up to seven different locations in the Central and Southern Indian Basin to assess the peak periods of presence, seasonality and migration movements of Antarctic blue whales (Balaenoptera musculus intermedia). An automated method is used to detect the Antarctic blue whale stereotyped call, known as Z-call. Detection results are analyzed in terms of distribution, seasonal presence and diel pattern of emission at each site. Z-calls are detected year-round at each site, except for one located in the equatorial Indian Ocean, and display highly seasonal distribution. This seasonality is stable across years for every site, but varies between sites. Z-calls are mainly detected during autumn and spring at the subantarctic locations, suggesting that these sites are on the Antarctic blue whale migration routes, and mostly during winter at the subtropical sites. In addition to these seasonal trends, there is a significant diel pattern in Z-call emission, with more Z-calls in daytime than in nighttime. This diel pattern may be related to the blue whale feeding ecology.
Leroy, Emmanuelle C.; Samaran, Flore; Bonnel, Julien; Royer, Jean-Yves
2016-01-01
Passive acoustic monitoring is an efficient way to provide insights on the ecology of large whales. This approach allows for long-term and species-specific monitoring over large areas. In this study, we examined six years (2010 to 2015) of continuous acoustic recordings at up to seven different locations in the Central and Southern Indian Basin to assess the peak periods of presence, seasonality and migration movements of Antarctic blue whales (Balaenoptera musculus intermedia). An automated method is used to detect the Antarctic blue whale stereotyped call, known as Z-call. Detection results are analyzed in terms of distribution, seasonal presence and diel pattern of emission at each site. Z-calls are detected year-round at each site, except for one located in the equatorial Indian Ocean, and display highly seasonal distribution. This seasonality is stable across years for every site, but varies between sites. Z-calls are mainly detected during autumn and spring at the subantarctic locations, suggesting that these sites are on the Antarctic blue whale migration routes, and mostly during winter at the subtropical sites. In addition to these seasonal trends, there is a significant diel pattern in Z-call emission, with more Z-calls in daytime than in nighttime. This diel pattern may be related to the blue whale feeding ecology. PMID:27828976
Renoult, Julien P.; Schaefer, H. Martin; Sallé, Bettina; Charpentier, Marie J. E.
2011-01-01
Multicomponent signals consist of several traits that are perceived as a whole. Although many animals rely on multicomponent signals to communicate, the selective pressures shaping these signals are still poorly understood. Previous work has mainly investigated the evolution of multicomponent signals by studying each trait individually, which may not accurately reflect the selective pressures exerted by the holistic perception of signal receivers. Here, we study the design of the multicoloured face of an Old World primate, the mandrill (Mandrillus sphinx), in relation to two aspects of signalling that are expected to be selected by receivers: conspicuousness and information. Using reflectance data on the blue and red colours of the faces of 34 males and a new method of hue vectorisation in a perceptual space of colour vision, we show that the blue hue maximises contrasts to both the red hue and the foliage background colouration, thereby increasing the conspicuousness of the whole display. We further show that although blue saturation, red saturation and the contrast between blue and red colours are all correlated with dominance, dominance is most accurately indicated by the blue-red contrast. Taken together our results suggest that the evolution of blue and red facial colours in male mandrills are not independent and are likely driven by the holistic perception of conspecifics. In this view, we propose that the multicoloured face of mandrills acts as a multicomponent signal. Last, we show that information accuracy increases with the conspicuousness of the whole display, indicating that both aspects of signalling can evolve in concert. PMID:22216180
Shukla, Animesh; Biswas, Avijit; Blot, Nicolas; Partensky, Frédéric; Karty, Jonathan A; Hammad, Loubna A; Garczarek, Laurence; Gutu, Andrian; Schluchter, Wendy M; Kehoe, David M
2012-12-04
The marine cyanobacterium Synechococcus is the second most abundant phytoplanktonic organism in the world's oceans. The ubiquity of this genus is in large part due to its use of a diverse set of photosynthetic light-harvesting pigments called phycobiliproteins, which allow it to efficiently exploit a wide range of light colors. Here we uncover a pivotal molecular mechanism underpinning a widespread response among marine Synechococcus cells known as "type IV chromatic acclimation" (CA4). During this process, the pigmentation of the two main phycobiliproteins of this organism, phycoerythrins I and II, is reversibly modified to match changes in the ambient light color so as to maximize photon capture for photosynthesis. CA4 involves the replacement of three molecules of the green light-absorbing chromophore phycoerythrobilin with an equivalent number of the blue light-absorbing chromophore phycourobilin when cells are shifted from green to blue light, and the reverse after a shift from blue to green light. We have identified and characterized MpeZ, an enzyme critical for CA4 in marine Synechococcus. MpeZ attaches phycoerythrobilin to cysteine-83 of the α-subunit of phycoerythrin II and isomerizes it to phycourobilin. mpeZ RNA is six times more abundant in blue light, suggesting that its proper regulation is critical for CA4. Furthermore, mpeZ mutants fail to normally acclimate in blue light. These findings provide insights into the molecular mechanisms controlling an ecologically important photosynthetic process and identify a unique class of phycoerythrin lyase/isomerases, which will further expand the already widespread use of phycoerythrin in biotechnology and cell biology applications.
Shukla, Animesh; Biswas, Avijit; Blot, Nicolas; Partensky, Frédéric; Karty, Jonathan A.; Hammad, Loubna A.; Garczarek, Laurence; Gutu, Andrian; Schluchter, Wendy M.; Kehoe, David M.
2012-01-01
The marine cyanobacterium Synechococcus is the second most abundant phytoplanktonic organism in the world's oceans. The ubiquity of this genus is in large part due to its use of a diverse set of photosynthetic light-harvesting pigments called phycobiliproteins, which allow it to efficiently exploit a wide range of light colors. Here we uncover a pivotal molecular mechanism underpinning a widespread response among marine Synechococcus cells known as “type IV chromatic acclimation” (CA4). During this process, the pigmentation of the two main phycobiliproteins of this organism, phycoerythrins I and II, is reversibly modified to match changes in the ambient light color so as to maximize photon capture for photosynthesis. CA4 involves the replacement of three molecules of the green light-absorbing chromophore phycoerythrobilin with an equivalent number of the blue light-absorbing chromophore phycourobilin when cells are shifted from green to blue light, and the reverse after a shift from blue to green light. We have identified and characterized MpeZ, an enzyme critical for CA4 in marine Synechococcus. MpeZ attaches phycoerythrobilin to cysteine-83 of the α-subunit of phycoerythrin II and isomerizes it to phycourobilin. mpeZ RNA is six times more abundant in blue light, suggesting that its proper regulation is critical for CA4. Furthermore, mpeZ mutants fail to normally acclimate in blue light. These findings provide insights into the molecular mechanisms controlling an ecologically important photosynthetic process and identify a unique class of phycoerythrin lyase/isomerases, which will further expand the already widespread use of phycoerythrin in biotechnology and cell biology applications. PMID:23161909
Lateral trends and vertical sequences in estuarine sediments, Willapa Bay, Washington
Clifton, H. Edward; Phillips, L.
1980-01-01
Willapa Bay is a sizable estuary on the southern coast of Washington- Relatively unmodified in a geologic sense by human activity the bay provides an excellent example of modern depositional facies in an estuarine setting. Studies of these deposits indicate that consistent lateral trends exist in sediment texture and sedimentary structures. The texture changes from sandy at the mouth of the bay to muddy in its upper parts. In any part of the bay , sediment is coarsest in the channel bottoms, where lag deposits accumulate. The sediment tends to fine in an upslope direction and is finest in supratidal flat deposits of silt and clay. The nature of sedimentary structures depends on the combination of physical and biological processes and sediment textures. Bedforms exist wherever the bed is sandy. In the main tidal channels sandwaves and dunes up to 4 meters high occur. In tributary channels and at the margins of the main channel, at shallower depths and under less intense currents , the structures are generally less than a meter high. Current ripples occur in t he sandy bed of all of the tidal channels and in runoff channels cross the tidal flat. Symmetric long-crested ripples are produced by wave action over the sandy intertidal flat. Internal structures in the bay's sediment depend not only on the nature of the bedform but also on the rate of bioturbation relative to physical processes. Under fields of large sandwaves or dunes, medium- to large-scale tabular and trough crossbedding predominates. This crossbedding generally is unidirectional, reflecting the locally dominant current (ebb or flood). Ripple bedding predominates elsewhere in sandy sediment within the channels. Where sand transport is diminished, as on the floor of the upper tributary channels, bioturbation exceeds the rate of production of physical structures and bedding is destroyed. The depositional banks in such areas tend to be sites of rapid sediment accumulation and bedding in the form of interlayered sand (commonly ripple bedded) and mud persists. On intertidal flats the sediment accumulates slowly and bioturbation erases nearly all physical structures. Bedding is preserved only where deposition is locally rapid , as in topographic depressions or on the depositional banks of runoff channels, or where faunal activity is inhibited, as beneath mounds of blue-green algae. The rate of sedimentation is slower still on the supratidal flats, but the general paucity of faunal activity allows the preservation of thin alternations of fine sand , silt or clay. The lateral migration of the tidal channels produces vertical sequences in which topographically higher facies are superposed on one another. Near the mouth of the estuary the upward sequence: lag deposit — crossbedded sand — ripple or planar-bedded sand is typical. The crossbedding shows a general upward decrease in thickness and a progression from trough to tabular units. In the main tidal channel - in the central estuary and in sandy tributary channels, the typical vertical sequence resembles that near the mouth , with the exception that the sequence is capped by bioturbated sandy or muddy tide flat deposits. In the upper estuary , where muddy sediment predominates, a typical sequence shows the progression-. bioturbated lag deposit — gently dipping interlaminated sand and mud layers of the accretionary bank — bioturbated mud flat deposits — thinly laminated fine supratidal deposits.
On the Detection and Characterization of Polluted White Dwarfs
NASA Astrophysics Data System (ADS)
Steele, Amy; Debes, John H.; Deming, Drake
2017-06-01
There is evidence of circumstellar material around main sequence, giant, and white dwarf stars. What happens to this material after the main sequence? With this work, we focus on the characterization of the material around WD 1145+017. The goals are to monitor the white dwarf—which has a transiting, disintegrating planetesimal and determine the composition of the evaporated material for that same white dwarf by looking at high-resolution spectra. We also present preliminary results of follow-up photometric observations of known polluted WDs. If rocky bodies survive red giant branch evolution, then the material raining down on a WD atmosphere is a direct probe of main sequence cosmochemistry. If rocky bodies do not survive the evolution, then this informs the degree of post-main-sequence processing. These case studies will provide the community with further insight about debris disk modeling, the degree of post-main-sequence processing of circumstellar material, and the composition of a disintegrating planetesimal.
Pan, Hong-zhi; Yu, Hong- Wei; Wang, Na; Zhang, Ze; Wan, Guang-Cai; Liu, Hao; Guan, Xue; Chang, Dong
2015-01-01
To develop a new electrochemical DNA biosensor for determination of Klebsiella pneumoniae carbapenemase, a highly sensitive and selective electrochemical biosensor for DNA detection was constructed based on a glassy carbon electrode (GCE) modified with gold nanoparticles (Au-nano). The Au-nano/GCE was characterized by scanning electromicroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The hybridization detection was measured by differential pulse voltammetry using methylene blue as the hybridization indicator. The dynamic range of detection of the sensor for the target DNA sequences was from 1 × 10(-11) to 1 × 10(-8) M, with an LOD of 1 × 10(-12) M. The DNA biosensor had excellent specificity for distinguishing complementary DNA sequence in the presence of non-complementary and mismatched DNA sequence. The Au-nano/GCE showed significant improvement in electrochemical characteristics, and this biosensor was successfully applied for determination of K. pneumoniae.
A catalog of aftershock sequences in Greece (1971 1997): Their spatial and temporal characteristics
NASA Astrophysics Data System (ADS)
Drakatos, George; Latoussakis, John
A complete catalog of aftershock sequences is provided for main earthquakes with ML 5.0, which occurred in the area of Greece and surrounding regions the last twenty-seven years. The Monthly Bulletins of the Institute of Geodynamics (National Observatory of Athens) have been used as data source. In order to get a homogeneous catalog, several selection criteria have been applied and hence a catalog of 44 aftershock sequences is compiled. The relations between the duration of the sequence, the number of aftershocks, the magnitude of the largest aftershock and its delay time from the main shock as well as the subsurface rupture length versus the magnitude of the main shock are calculated. The results show that linearity exists between the subsurface rupture length and the magnitude of the main shock independent of the slip type, as well as between the magnitude of the main shock (M) and its largest aftershock (Ma). The mean difference M-Ma is almost one unit. In the 40% of the analyzed sequences, the largest aftershock occurred within one day after the main shock.The fact that the aftershock sequences show the same behavior for earthquakes that occur in the same region supports the theory that the spatial and temporal characteristics are strongly related to the stress distribution of the fault area.
Testardini, Pamela; Vaulet, María Lucía Gallo; Entrocassi, Andrea Carolina; Menghi, Claudia; Eliseht, Martha Cora; Gatta, Claudia; Losada, Mirta; Touzón, María Sol; Corominas, Ana; Vay, Carlos; Tatti, Silvio; Famiglietti, Angela; Fermepin, Marcelo Rodriguez; Perazzi, Beatriz
2016-04-01
The aim of this study was to evaluate different methods for Trichomonas vaginalis diagnosis during pregnancy in order to prevent maternal and perinatal complications. A total of 386 vaginal exudates from pregnant women were analyzed. T. vaginalis was investigated by 3 types of microscopic examinations direct wet mount with physiologic saline solution, prolonged May-Grunwald Giemsa (MGG) staining, and wet mount with sodium-acetate-formalin (SAF)/methylene blue method. PCR for 18S rRNA gene as well as culture in liquid medium were performed. The sensitivity and specificity of the microscopic examinations were evaluated considering the culture media positivity or the PCR techniques as gold standard. The frequency of T. vaginalis infection was 6.2% by culture and/or PCR, 5.2% by PCR, 4.7% by culture, 3.1% by SAF/methylene blue method and 2.8% by direct wet smear and prolonged MGG staining. The sensitivities were 83.3%, 75.0%, 50.0%, and 45.8% for PCR, culture, SAF/methylene blue method, and direct wet smear-prolonged MGG staining, respectively. The specificity was 100% for all the assessed methods. Microscopic examinations showed low sensitivity, mainly in asymptomatic pregnant patients. It is necessary to improve the detection of T. vaginalis using combined methods providing higher sensitivity, such as culture and PCR, mainly in asymptomatic pregnant patients, in order to prevent maternal and perinatal complications.
A multi-wavelength study of the evolution of early-type galaxies in groups: the ultraviolet view
NASA Astrophysics Data System (ADS)
Rampazzo, R.; Mazzei, P.; Marino, A.; Bianchi, L.; Plana, H.; Trinchieri, G.; Uslenghi, M.; Wolter, A.
2018-04-01
The ultraviolet-optical colour magnitude diagram of rich galaxy groups is characterised by a well developed Red Sequence, a Blue Cloud and the so-called Green Valley. Loose, less evolved groups of galaxies which are probably not virialised yet may lack a well defined Red Sequence. This is actually explained in the framework of galaxy evolution. We are focussing on understanding galaxy migration towards the Red Sequence, checking for signatures of such a transition in their photometric and morphological properties. We report on the ultraviolet properties of a sample of early-type (ellipticals+S0s) galaxies inhabiting the Red Sequence. The analysis of their structures, as derived by fitting a Sérsic law to their ultraviolet luminosity profiles, suggests the presence of an underlying disk. This is the hallmark of dissipation processes that still must have a role to play in the evolution of this class of galaxies. Smooth particle hydrodynamic simulations with chemo-photometric implementations able to match the global properties of our targets are used to derive their evolutionary paths through ultraviolet-optical colour magnitude diagrams, providing some fundamental information such as the crossing time through the Green Valley, which depends on their luminosity. The transition from the Blue Cloud to the Red Sequence takes several Gyrs, being about 3-5 Gyr for the brightest galaxies and longer for fainter ones, if occurring. The photometric study of nearby galaxy structures in the ultraviolet is seriously hampered by either the limited field of view of the cameras (e.g., in Hubble Space Telescope) or by the low spatial resolution of the images (e.g., in the Galaxy Evolution Explorer). Current missions equipped with telescopes and cameras sensitive to ultraviolet wavelengths, such as Swift- UVOT and Astrosat-UVIT, provide a relatively large field of view and a better resolution than the Galaxy Evolution Explorer. More powerful ultraviolet instruments (size, resolution and field of view) are obviously bound to yield fundamental advances in the accuracy and depth of the surface photometry and in the characterisation of the galaxy environment.
Spectral lines behavior of Be I and Na I isoelectronic sequence in Debye plasma environment
NASA Astrophysics Data System (ADS)
Chaudhuri, Rajat K.; Chattopadhyay, Sudip; Sinha Mahapatra, Uttam
2012-08-01
We report the plasma screening effect on the first ionization potential (IP) and [He]2s2(1S0)→[He]2s2p /2s3p allowed (P11) and inter-combination transitions (P31) in some selected Be-like ions. In addition, we investigate the spectral properties of [Ne]3s (2S1/2)→[Ne]np(2P1/2 and P23/2 for n = 3, 4) transitions in Ca X and Fe XVI ions (Na I isoelectronic sequence) and [He]3s(2S1/2)→[He]np(2P1/2 and P23/2 for n = 2, 3) transitions in Li, B II, and N IV (Li I isoelectronic sequence) under plasma environment. The state-of-the-art relativistic coupled cluster calculations using the Debye model of plasma for electron-nucleus interaction show that (a) the ionization potential decreases sharply with increasing plasma strength and (b) the gap between the [He]2s2(1S0)→[He]2s2p(1,3P1) energy levels increases with increasing plasma potential and nuclear charge. It is found that the [He]2s2 (1S0)→2s3p(1,3P1) transition energy decreases uniformly with increasing plasma potential and nuclear charge. In other words, the spectral lines associated with 2s-2p (i.e., Δn=0, where n corresponds to principle quantum number) transitions in Be I isoelectronic sequence exhibit a blue-shift (except for Be I, B II, and the lowest inter-combination line in C III, which exhibit a red-shift), whereas those associated with 2s-3p (i.e., Δn≠0) transitions are red-shifted. Similar trend is observed in Li I and Na I isoelectronic sequences, where spectral lines associated with Δn=0 (Δn≠0) are blue-shifted (red-shifted). The effect of Coulomb screening on the spectral lines of ions subjected to plasma is also addressed.
Prokaryotic algae associated with Australian proterozoic stromatolites.
NASA Technical Reports Server (NTRS)
Licari, G. R.; Cloud, P.
1972-01-01
The most favorable sites in which to study the associations between stromatolites and the algae responsible for them are places where a variety of stromatolites of possibly early diagenetic or primary silica occupy a layer of substantial thickness of little metamorphosed ancient sediments. One such place is in northwestern Queensland, Australia. Five cases of association between stromatolites and blue-green algal nannofossils were observed within a 100-m sequence of carbonate rocks in that area.
Columbia/Einstein observations of galactic X-ray sources
NASA Technical Reports Server (NTRS)
Long, K. S.
1979-01-01
The imaging observations of galactic clusters are presented. These fall into three categories: pre-main-sequence stars in the Orion nebulae, isolated-main-and-post main-sequence stars, and supernova remnants SNR. In addition to SNR, approximately 30 sources were detected.
Lucia, S; Cercignani, G; Frediani, A; Petracchi, D
2003-01-01
Behavioral responses of Halobacterium salinarum appear as changes in the frequency of motion reversals. Turning on orange light decreases the reversal frequency, whereas blue light induces reversals. Light pulses normally induce the same response as step-up stimuli. However, anomalous behavioral reactions, including inverse responses, are seen when stimuli are applied in sequence. The occurrence of a prior stimulus is conditioning for successive stimulation on a time scale of the same order of adaptational processes. These prolonged conditioning effects are color-specific. The only adaptation process identified so far is methylation of the transducers, and this could be somehow color-specific. Therefore we tested for the behavioral anomalies in a mutant in which all methylation sites on the transducer have been eliminated. The results show that behavioral anomalies are unaffected by the absence of methylation processes on the transducer.
Recent developments in white light emitting diodes
NASA Astrophysics Data System (ADS)
Lohe, P. P.; Nandanwar, D. V.; Belsare, P. D.; Moharil, S. V.
2018-05-01
In the recent years solid state lighting based on LEDs has revolutionized lighting technology. LEDs have many advantages over the conventional lighting based on fluorescent and incandescent lamps such as mercury free, high conversion efficiency of electrical energy into light, long lifetime reliability and ability to use with many types of devices. LEDs have emerged as a new potentially revolutionary technology that could save up to half of energy used for lighting applications. White LEDs would be the most important light source in the future, so much so that this aspect had been highlighted by the Nobel committee during the award of 2014 Nobel Prize for Physics. Recent advancement in the fabrication of GaN chip capable of emitting in blue and near UV region paved way for fabrication of white LED lamps. Mainly there are two approaches used for preparing white emitting solid state lamp. In the first approach blue light (λ=450 nm) emitted from the InGaN LED chip is partially absorbed by the YAG:Ce3+ phosphor coated on it and re-emitted as yellow fluorescence. A white light can be generated by the combination of blue + yellow emission bands. These lamps are already available. But they are suffering from major drawback that their Colour Rendering Index (CRI) is low. In the second approach, white LEDs are made by coating near ultraviolet emitting (360 to 410nm) LED with a mixture of high efficiency red, green and blue emitting phosphors, analogous to the fluorescent lamp. This method yields lamps with better color rendition. Addition of a yellow emitting phosphor improves CRI further. However conversion efficiency is compromised to some extent. Further the cost of near UV emitting chip is very high compared to blue emitting chips. Thus cost and light output wise, near UV chips are much inferior to blue chips. Recently some rare earth activated oxynitrides, silicates, fluorides have emerged as an important family of luminescent materials for white LED application because they can emit visible light strongly under blue light irradiation. These are chemically, thermally and mechanically stable materials with high efficiency to down convert blue radiation into green and red. Efficient white light can be generated by coating these phosphors on blue LED.CRI of white emitting LED lamp can be improved significantly if green and red emitting phosphors are coated on efficient blue emitting LED chips. In this approach CRI will be maintained if appropriate combination of red, green along with blue emission is used. This article reviews some recent developments in phosphors for white light emitting diodes.
Volcanic ash layers in blue ice fields (Beardmore Glacier Area, Antarctica): Iridium enrichments
NASA Technical Reports Server (NTRS)
Koeberl, Christian
1988-01-01
Dust bands on blue ice fields in Antarctica have been studied and have been identified to originate from two main sources: bedrock debris scraped up from the ground by the glacial movement (these bands are found predominantly at fractures and shear zones in the ice near moraines), and volcanic debris deposited on and incorporated in the ice by large-scale eruptions of Antarctic (or sub-Antractic) volcanoes. Ice core studies have revealed that most of the dust layers in the ice cores are volcanic (tephra) deposits which may be related to some specific volcanic eruptions. These eruptions have to be related to some specific volcanic eruptions. These eruptions have to be relatively recent (a few thousand years old) since ice cores usually incorporate younger ice. In contrast, dust bands on bare blue ice fields are much older, up to a few hundred thousand years, which may be inferred from the rather high terrestrial age of meteorites found on the ice and from dating the ice using the uranium series method. Also for the volcanic ash layers found on blue ice fields correlations between some specific volcanoes (late Cenozoic) and the volcanic debris have been inferred, mainly using chemical arguments. During a recent field expedition samples of several dust bands found on blue ice fields at the Lewis Cliff Ice Tongue were taken. These dust band samples were divided for age determination using the uranium series method, and chemical investigations to determine the source and origin of the dust bands. The investigations have shown that most of the dust bands found at the Ice Tongue are of volcanic origin and, for chemical and petrological reasons, may be correlated with Cenozoic volcanoes in the Melbourne volcanic province, Northern Victoria Land, which is at least 1500 km away. Major and trace element data have been obtained and have been used for identification and correlation purposes. Recently, some additional trace elements were determined in some of the dust band samples, including Ir. Iridium determinations were made using INAA, with synthetical and natural (meteorite) standards. These findings are discussed.
Prof. Hayashi's work on the pre-main sequence evolution and brown dwarfs
NASA Astrophysics Data System (ADS)
Nakano, Takenori
2012-09-01
Prof. Hayashi's work on the evolution of stars in the pre-main sequence stage is reviewed. The historical background and the process of finding the Hayashi phase are mentioned. The work on the evolution of low-mass stars is also reviewed including the determination of the bottom of the main sequence and evolution of brown dwarfs, and comparison is made with the other works in the same period.
Kosnarite, KZr2(PO4)3, a new mineral from Mount Mica and Black Mountain, Oxford County, Maine
Brownfield, M.E.; Foord, E.E.; Sutley, S.J.; Botinelly, T.
1993-01-01
Kosnarite, ideally KZr2(PO4)3, has been identified as part of a late-stage, secondary phosphate mineral assemblage from the Mount Mica pegmatite at Paris, and from the Black Mountain pegmatite, Rumford, Oxford County, Maine. Kosnarite from Mount Mica occurs as pseudocubic rhombohedral crystals, as much as 0.9 mm in maximum dimension, that display the dominant {102} form. Color ranges from pale blue to blue-green to nearly colorless. The mineral has a white streak, is transparent, has a vitreous luster, and is nonfluorescent in ultraviolet light. It has a hardness of 4.5, is brittle with a conchoidal fracture, and has perfect {102} cleavage. Kosnarite from Black Mountain is almost pure KZr2(PO4)3 with only trace amounts of Hf, Mn, Na, and Rb. The mineral is one of three known alkali zirconium phosphates; the others are gainesite and the Cs analogue of gainesite. -from Author
The size evolution of star-forming and quenched galaxies in the IllustrisTNG simulation
NASA Astrophysics Data System (ADS)
Genel, Shy; Nelson, Dylan; Pillepich, Annalisa; Springel, Volker; Pakmor, Rüdiger; Weinberger, Rainer; Hernquist, Lars; Naiman, Jill; Vogelsberger, Mark; Marinacci, Federico; Torrey, Paul
2018-03-01
We analyse scaling relations and evolution histories of galaxy sizes in TNG100, part of the IllustrisTNG simulation suite. Observational qualitative trends of size with stellar mass, star formation rate and redshift are reproduced, and a quantitative comparison of projected r band sizes at 0 ≲ z ≲ 2 shows agreement to much better than 0.25 dex. We follow populations of z = 0 galaxies with a range of masses backwards in time along their main progenitor branches, distinguishing between main-sequence and quenched galaxies. Our main findings are as follows. (i) At M*, z = 0 ≳ 109.5 M⊙, the evolution of the median main progenitor differs, with quenched galaxies hardly growing in median size before quenching, whereas main-sequence galaxies grow their median size continuously, thus opening a gap from the progenitors of quenched galaxies. This is partly because the main-sequence high-redshift progenitors of quenched z = 0 galaxies are drawn from the lower end of the size distribution of the overall population of main-sequence high-redshift galaxies. (ii) Quenched galaxies with M*, z = 0 ≳ 109.5 M⊙ experience a steep size growth on the size-mass plane after their quenching time, but with the exception of galaxies with M*, z = 0 ≳ 1011 M⊙, the size growth after quenching is small in absolute terms, such that most of the size (and mass) growth of quenched galaxies (and its variation among them) occurs while they are still on the main sequence. After they become quenched, the size growth rate of quenched galaxies as a function of time, as opposed to versus mass, is similar to that of main-sequence galaxies. Hence, the size gap is retained down to z = 0.
Hereditary cataracts in Russian Blue cats.
Nygren, Karin; Jalomäki, Sari; Karlstam, Lena; Narfström, Kristina
2018-01-01
Objectives The purpose of this study was to investigate the prevalence of cataracts in the Russian Blue breed of cats in Sweden, and to describe the clinical appearance of this presumed inherited form of cataract. Methods A total of 66 Russian Blue cats were examined in Sweden, between March and October 2014, using standard examination techniques. The examined cats were between 3 months and 14 years of age. Pedigrees were collected from all examined cats for genetic studies. Results Mild-to-severe forms of mainly bilateral cataracts were observed in 22/66 examined Russian Blue cats of both sexes. Two affected cats were <1 year of age. The most frequently observed appearance of a cataract was a small triangular, Y-shaped or circular opacity at the border of the posterior nucleus and the anterior part of the posterior cortex, which caused no observable visual impairment. More extended forms were observed in 6/22 cats, with involvement of both the nucleus and either the entire cortex or parts of the posterior and/or anterior cortex. Visual impairment or blindness was observed in the latter six cases. Pedigree analyses indicated a simple autosomal recessive mode of inheritance for the defect, although a dominant mode with incomplete penetrance could not be excluded. Conclusions and relevance This study indicates that the Russian Blue breed of cat is affected by hereditary cataracts. The high prevalence in young cats and the characteristic location of the most frequently observed defect in the study suggest an early onset type of cataract. The breeders should be aware of this defect and have their cats examined by a veterinary ophthalmologist before breeding of an individual Russian Blue cat is considered.
(Virtual) Water Flows Uphill toward Money.
Wang, Ranran; Hertwich, Edgar; Zimmerman, Julie B
2016-11-15
This study provides a more precise understanding of the main driving forces of anthropogenic water use across countries. The anthropogenic water use was distinguished as blue water (i.e., fresh surface and groundwater) and total water (i.e. blue + green water; green water is rainwater insofar as it does not become runoff) used for producing, consuming, exporting, and importing of primary and manufactured goods and services, measured on a per country and per capita basis. The population effect on national blue water consumption associated with producing and consuming was found to be bigger than what the commonly assumed unitary population elasticity indicates. Distinct from the homogeneous affluence-water relationships conventionally assumed, this study revealed varying and potentially opposite effects affluence can have depending on the water use account of interest (e.g., production-based or consumption-based, blue or green) and the income level. Affluence, not the availability of freshwater resources, was found to be the most critical driver of virtual water imports. And a more affluent lifestyle in high-income countries was still associated with greater blue water consumption. With each doubling of income, blue water embedded in the goods and services a nation consumed and imported on a per capita basis increased by 82% and 86%, respectively, across the 110 countries analyzed for 2007. In comparison to affluence, the varying per capita water consumption accounts across the nations were much less sensitive to food consumption patterns. Given its critical role for water, land, and energy use shown by this and previous studies, affluence should be taken as a critical factor in future studies to better understand and leverage the water-energy-food-land nexus.
A novel blue-light phototropic response is revealed in roots of Arabidopsis thaliana in microgravity
Vandenbrink, Joshua P.; Herranz, Raul; Medina, F. Javier; Edelmann, Richard E.
2017-01-01
Main conclusion Blue-light positive phototropism in roots is masked by gravity and revealed in conditions of microgravity. In addition, the magnitude of red-light positive phototropic curvature is correlated to the magnitude of gravity. Due to their sessile nature, plants utilize environmental cues to grow and respond to their surroundings. Two of these cues, light and gravity, play a substantial role in plant orientation and directed growth movements (tropisms). However, very little is currently known about the interaction between light- (phototropic) and gravity (gravitropic)-mediated growth responses. Utilizing the European Modular Cultivation System on board the International Space Station, we investigated the interaction between phototropic and gravitropic responses in three Arabidopsis thaliana genotypes, Landsberg wild type, as well as mutants of phytochrome A and phytochrome B. Onboard centrifuges were used to create a fractional gravity gradient ranging from reduced gravity up to 1g. A novel positive blue-light phototropic response of roots was observed during conditions of microgravity, and this response was attenuated at 0.1g. In addition, a red-light pretreatment of plants enhanced the magnitude of positive phototropic curvature of roots in response to blue illumination. In addition, a positive phototropic response of roots was observed when exposed to red light, and a decrease in response was gradual and correlated with the increase in gravity. The positive red-light phototropic curvature of hypocotyls when exposed to red light was also confirmed. Both red-light and blue-light phototropic responses were also shown to be affected by directional light intensity. To our knowledge, this is the first characterization of a positive blue-light phototropic response in Arabidopsis roots, as well as the first description of the relationship between these phototropic responses in fractional or reduced gravities. PMID:27507239
Sickness benefit cuts mainly affect blue-collar workers.
Aaviksoo, E; Kiivet, R-A
2014-08-01
To analyse the impact of sick-pay cuts on the use of sickness absence by employees of different socioeconomic groups. In 2009 cuts in sick pay were implemented in reaction to an economic crisis in Estonia. Nationwide health survey data from the years 2004, 2006, 2008, and 2010 were used to evaluate sickness absence among blue-collar and white-collar workers. The dataset comprised 7,449 employees of 20-64 years of age. Difference in prevalence of absentees before and after the reform was assessed using the chi-squared test. Odds ratios (OR) for sickness absence were calculated in a multivariate logistic regression model. After the reform, the proportion of blue-collar workers who had been on sick leave decreased from 51% to 40% (p<0.001) and among white-collar employees from 45% to 41% (p=0.026). This reduction had a similar pattern in all the subgroups of blue-collar employees as stratified according to gender, age, self-rated health, and presence of chronic disease, especially among those with low incomes; in white-collar employees it reached statistical significance only in those with good self-rated health (p=0.033). In a multivariate model the odds of having lower sickness absence were highly significant only in blue-collar employees (OR 0.63; 95% confidence interval 0.51-0.77, p<0.001). The cuts in sickness benefits had a major impact on the use of sickness absence by blue-collar employees with low salaries. This indicates that lower income was a major factor hindering the use of sick leave as these employees are most vulnerable to the loss of income. © 2014 the Nordic Societies of Public Health.
NASA Astrophysics Data System (ADS)
Ellison, Sara L.; Sánchez, Sebastian F.; Ibarra-Medel, Hector; Antonio, Braulio; Mendel, J. Trevor; Barrera-Ballesteros, Jorge
2018-02-01
The tight correlation between total galaxy stellar mass and star formation rate (SFR) has become known as the star-forming main sequence. Using ˜487 000 spaxels from galaxies observed as part of the Sloan Digital Sky Survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, we confirm previous results that a correlation also exists between the surface densities of star formation (ΣSFR) and stellar mass (Σ⋆) on kpc scales, representing a `resolved' main sequence. Using a new metric (ΔΣSFR), which measures the relative enhancement or deficit of star formation on a spaxel-by-spaxel basis relative to the resolved main sequence, we investigate the SFR profiles of 864 galaxies as a function of their position relative to the global star-forming main sequence (ΔSFR). For galaxies above the global main sequence (positive ΔSFR) ΔΣSFR is elevated throughout the galaxy, but the greatest enhancement in star formation occurs at small radii (<3 kpc, or 0.5Re). Moreover, galaxies that are at least a factor of 3 above the main sequence show diluted gas phase metallicities out to 2Re, indicative of metal-poor gas inflows accompanying the starbursts. For quiescent/passive galaxies that lie at least a factor of 10 below the star-forming main sequence, there is an analogous deficit of star formation throughout the galaxy with the lowest values of ΔΣSFR in the central 3 kpc. Our results are in qualitative agreement with the `compaction' scenario in which a central starburst leads to mass growth in the bulge and may ultimately precede galactic quenching from the inside-out.
Gürses, A; Doğar, C; Karaca, S; Açikyildiz, M; Bayrak, R
2006-04-17
An activated carbon was developed from Rosa canina sp. seeds, characterized and used for the removal of methylene blue (basic dye) from aqueous solutions. Adsorption studies were carried out at 20 degrees C and various initial dye concentrations (20, 40, 60, 80, and 100 mg/L) for different times (15, 30, 60, and 120 min). The adsorption isotherm was obtained from data. The results indicate that the adsorption isotherm of methylene blue is typically S-shaped. The shape of isotherm is believed to reflect three distinct modes of adsorption. In region 1, the adsorption of methylene blue is carried out mainly by ion exchange. In region 2 by polarizations of pi-electrons established at cyclic parts of the previously adsorbed methylene blue molecules is occurred. However, it is not observed any change at the sign of the surface charge although zeta potential value is decreased with increase of amount adsorbed. In region 3, the slope of the isotherm is reduced, because adsorption now must overcome electrostatic repulsion between oncoming ions and the similarly charged solid. Adsorption in this fashion is usually complete when the surface is covered with a monolayer of methylene blue. To reveal the adsorptive characteristics of the produced active carbon, porosity and BET surface area measurements were made. Structural analysis was performed using SEM-EDS. The produced active carbon has the specific surface area of 799.2 m2 g-1 and the iodine number of 495 mg/g.
[The dangers of blue light: True story!].
Renard, G; Leid, J
2016-05-01
The dangers of the blue light are the object of numerous publications, for both the scientific community and the general public. The new prolific development of light sources emitting potentially toxic blue light (415-455nm) ranges from LED (Light Emitting Diodes) lamps for interior lighting to television screens, computers, digital tablets and smartphones using OLED (Organic Light Emitting Diode) or AMOLED (Active-Matrix Organic Light Emitting Diode) technology. First we will review some technical terms and the main characteristics of light perceived by the human eye. Then we will discuss scientific proof of the toxicity of blue light to the eye, which may cause cataract or macular degeneration. Analysis of the light spectra of several light sources, from natural light to LED lamps, will allow us to specify even better the dangers related to each light source. LED lamps, whether used as components for interior lighting or screens, are of concern if they are used for extended viewing times and at short distance. While we can protect ourselves from natural blue light by wearing colored glasses which filter out, on both front and back surfaces, the toxic wavelengths, it is more difficult to protect oneself from LED lamps in internal lighting, the use of which should be restricted to "white warmth" lamps (2700K). As far as OLED or AMOLED screens are concerned, the only effective protection consists of using them occasionally and only for a short period of time. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Earth observations taken from shuttle orbiter Columbia during STS-87 mission
1997-11-26
STS087-717-088 (19 November 5 December 1997) --- Featured in this view are Sudans agricultural projects dependent on irrigation. Just southeast of the confluence of the Blue and White Nile rivers (and the city of Khartoum) is one of the largest irrigation projects in the world, known as the Gezira Scheme. The economy of Sudan is largely based on agriculture. The Gezira Scheme was begun by the British in 1925 and distributes water from the Blue Nile through canals and ditches to tenant farms lying between the Blue and White Nile rivers. Farmers cooperate with the Sudanese government and the Gezira Board. This network of canals and ditches is 2,700 miles (4,300 kilometers) long, and the irrigated area covers 2.5 million acres (1 million hectares). The main crop grown in this region is cotton. This picture is one of the 70mm Earth observations visuals used by the crew at its post flight presentation events.
2017-08-11
NASA's Cassini spacecraft looks toward the night side of Saturn's moon Titan in a view that highlights the extended, hazy nature of the moon's atmosphere. During its long mission at Saturn, Cassini has frequently observed Titan at viewing angles like this, where the atmosphere is backlit by the Sun, in order to make visible the structure of the hazes. Titan's high-altitude haze layer appears blue here, whereas the main atmospheric haze is orange. The difference in color could be due to particle sizes in the haze. The blue haze likely consists of smaller particles than the orange haze. Images taken using red, green and blue spectral filters were combined to create this natural-color view. The image was taken with the Cassini spacecraft narrow-angle camera on May 29, 2017. The view was acquired at a distance of approximately 1.2 million miles (2 million kilometers) from Titan. Image scale is 5 miles (9 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21625
Litmus paper helps detect potential pancreatoenterostomy leakage.
Yamaguchi, K; Chijiwa, K; Shimizu, S; Yokohata, K; Tanaka, M
1998-03-01
Leakage of pancreatoenterostomy remains as a serious and fatal complication after pancreatectomy. Several risk factors have been reported, ie, normal pancreatic parenchyma, small pancreatic duct, a large amount of intraoperative blood loss, management of the cut surface of the pancreas, and the presence of preoperative jaundice. Transected pancreatic ductules on the cut surface of the pancreas that are not drained into the main pancreatic duct after pancreatectomy are one of the risks. The pancreatic juice is alkaline and turns red litmus to blue. In order to detect the transected pancreatic ductules on the cut surface of the pancreas, red litmus paper is applied to the cutting surface of the pancreas after stimulation of secretin. Nondrained, transected pancreatic ductules on the cut surface of the pancreas can be detected as blue spots on the red litmus paper. The corresponding areas to the blue spots can be transfixed with sutures to close the nondrained and transected pancreatic ductules. Litmus paper can be expected to detect pancreatoenterostomy leakage after pancreatectomy.
Effect of Iron Oxide and Phase Separation on the Color of Blue Jun Ware Glaze.
Wang, Fen; Yang, Changan; Zhu, Jianfeng; Lin, Ying
2015-09-01
Based on the traditional Jun ware glaze, the imitated Jun ware glazes were prepared by adding iron oxide and introducing phase separation agent apatite through four-angle-method. The effect of iron oxide contents, phase separation and the firing temperature on the color of Jun ware glazes were investigated by a neutral atmosphere experiment, optical microscope and scanning electronic microscope. The results showed that the colorant, mainly Fe2O3, contributed to the Jun ware glaze blue and cyan colors of Jun ware glaze. The light scatter caused by the small droplets in phase separation structure only influenced the shade of the glaze color, intensify or weaken the color, and thus made the glaze perfect and elegant opal visual effects, but was not the origin of general blue or cyan colors of Jun ware glaze. In addition, the firing temperature and the basic glaze composition affected the glaze colors to some extent.
Lee, Sang-Hyo; Lee, Ju Eun; Kim, Yoori; Lee, Seung-Yop
2016-01-01
Phycocyanin is a photosynthetic pigment found in photosynthetic cyanobacteria, cryptophytes, and red algae. In general, production of phycocyanin depends mainly on the light conditions during the cultivation period, and purification of phycocyanin requires expensive and complex procedures. In this study, we propose a new two-stage cultivation method to maximize the quantitative content and purity of phycocyanin obtained from Spirulina platensis using red and blue light-emitting diodes (LEDs) under different light intensities. In the first stage, Spirulina was cultured under a combination of red and blue LEDs to obtain the fast growth rate until reaching an absorbance of 1.4-1.6 at 680 nm. Next, blue LEDs were used to enhance the concentration and purity of the phycocyanin in Spirulina. Two weeks of the two-stage cultivation of Spirulina yielded 1.28 mg mL(-1) phycocyanin with the purity of 2.7 (OD620/OD280).
Blue News Update: BODIPY-GTP Binds to the Blue-Light Receptor YtvA While GTP Does Not
Schmieder, Peter
2012-01-01
Light is an important environmental factor for almost all organisms. It is mainly used as an energy source but it is also a key factor for the regulation of multiple cellular functions. Light as the extracellular stimulus is thereby converted into an intracellular signal by photoreceptors that act as signal transducers. The blue-light receptor YtvA, a bacterial counterpart of plant phototropins, is involved in the stress response of Bacillus subtilis. The mechanism behind its activation, however, remains unknown. It was suggested based on fluorescence spectroscopic studies that YtvA function involves GTP binding and that this interaction is altered by absorption of light. We have investigated this interaction by several biophysical methods and show here using fluorescence spectroscopy, ITC titrations, and three NMR spectroscopic assays that while YtvA interacts with BODIPY-GTP as a fluorescent GTP analogue originally used for the detection of GTP binding, it does not bind GTP. PMID:22247770
The Role Of Rejuvenation In Shaping The High-Mass End Of The Main Sequence
NASA Astrophysics Data System (ADS)
Mancini, Chiara
2017-06-01
We investigate the nature of star forming galaxies with reduced specific SFRs and high stellar masses, those that seemingly cause the so-called bending of the main sequence. The fact that such objects host large bulges recently lead some to suggest that the internal formation of the bulges, via compaction or disk instabilities, was the late event that induced sSFRs of massive galaxies to drop in a slow downfall and thus the main sequence to bend. We have studied in detail a sample of 16 galaxies at 0.5
On the 3He anomaly in hot subdwarf B stars
NASA Astrophysics Data System (ADS)
Schneider, David; Irrgang, Andreas; Heber, Ulrich; Nieva, Maria F.; Przybilla, Norbert
2017-12-01
Decades ago, 3He isotope enrichment in helium-weak B-type main-sequence, in blue horizontal branch and in hot subdwarf B (sdB) stars, i.e., helium-core burning stars of the extreme horizontal branch, were discovered. Diffusion processes in the atmosphere of these stars lead to the observed abundance anomalies. Quantitative spectral analyses of high-resolution spectra to derive photospheric isotopic helium abundance ratios for known 3He sdBs have not been performed yet. We present preliminary results of high-resolution and high S/N spectra to determine the 3He and 4He abundances of nine known 3He sdBs. We used a hybrid local/non-local thermodynamic equilibrium (LTE/NLTE) approach for B-type stars investigating multiple He i lines, including λ4922 Å and λ6678 Å, which show the strongest isotopic shifts in the optical spectral range.We also report the discovery of four new 3He sdBs from the ESO Supernova Progenitor survey. Most of the 3He sdBs cluster in a narrow temperature strip between ˜ 26000 K and ˜ 30000 K and have almost no atmospheric 4He at all. Interestingly, three 3He sdBs show evidence for vertical helium stratification.
Spitzer Microlens Measurement of a Massive Remnant in a Well-separated Binary
NASA Astrophysics Data System (ADS)
Shvartzvald, Y.; Udalski, A.; Gould, A.; Han, C.; Bozza, V.; Friedmann, M.; Hundertmark, M.; and; Beichman, C.; Bryden, G.; Calchi Novati, S.; Carey, S.; Fausnaugh, M.; Gaudi, B. S.; Henderson, C. B.; Kerr, T.; Pogge, R. W.; Varricatt, W.; Wibking, B.; Yee, J. C.; Zhu, W.; Spitzer Team; Poleski, R.; Pawlak, M.; Szymański, M. K.; Skowron, J.; Mróz, P.; Kozłowski, S.; Wyrzykowski, Ł.; Pietrukowicz, P.; Pietrzyński, G.; Soszyński, I.; Ulaczyk, K.; OGLE Group; Choi, J.-Y.; Park, H.; Jung, Y. K.; Shin, I.-G.; Albrow, M. D.; Park, B.-G.; Kim, S.-L.; Lee, C.-U.; Cha, S.-M.; Kim, D.-J.; Lee, Y.; KMTNet Group; Maoz, D.; Kaspi, S.; Wise Group; Street, R. A.; Tsapras, Y.; Bachelet, E.; Dominik, M.; Bramich, D. M.; Horne, Keith; Snodgrass, C.; Steele, I. A.; Menzies, J.; Figuera Jaimes, R.; Wambsganss, J.; Schmidt, R.; Cassan, A.; Ranc, C.; Mao, S.; Dong, Subo; RoboNet; D'Ago, G.; Scarpetta, G.; Verma, P.; Jørgensen, U. G.; Kerins, E.; Skottfelt, J.; MiNDSTEp
2015-12-01
We report the detection and mass measurement of a binary lens OGLE-2015-BLG-1285La,b, with the more massive component having M1 > 1.35 M⊙ (80% probability). A main-sequence star in this mass range is ruled out by limits on blue light, meaning that a primary in this mass range must be a neutron star (NS) or black hole (BH). The system has a projected separation r⊥ = 6.1 ± 0.4 AU and lies in the Galactic bulge. These measurements are based on the “microlens parallax” effect, i.e., comparing the microlensing light curve as seen from Spitzer, which lay at 1.25 AU projected from Earth, to the light curves from four ground-based surveys, three in the optical and one in the near-infrared. Future adaptive optics imaging of the companion by 30 m class telescopes will yield a much more accurate measurement of the primary mass. This discovery both opens the path and defines the challenges to detecting and characterizing BHs and NSs in wide binaries, with either dark or luminous companions. In particular, we discuss lessons that can be applied to future Spitzer and Kepler K2 microlensing parallax observations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ogle, Patrick M.; Lanz, Lauranne; Nader, Cyril
We report the discovery of spiral galaxies that are as optically luminous as elliptical brightest cluster galaxies, with r-band monochromatic luminosity L{sub r} = 8–14L* (4.3–7.5 × 10{sup 44} erg s{sup −1}). These super spiral galaxies are also giant and massive, with diameter D = 57–134 kpc and stellar mass M{sub stars} = 0.3–3.4 × 10{sup 11}M{sub ⊙}. We find 53 super spirals out of a complete sample of 1616 SDSS galaxies with redshift z < 0.3 and L{sub r} > 8L*. The closest example is found at z = 0.089. We use existing photometry to estimate their stellar masses and star formation rates (SFRs). The SDSS and Wide-field Infrared Survey Explorer colors aremore » consistent with normal star-forming spirals on the blue sequence. However, the extreme masses and rapid SFRs of 5–65 M{sub ⊙} yr{sup −1} place super spirals in a sparsely populated region of parameter space, above the star-forming main sequence of disk galaxies. Super spirals occupy a diverse range of environments, from isolation to cluster centers. We find four super spiral galaxy systems that are late-stage major mergers—a possible clue to their formation. We suggest that super spirals are a remnant population of unquenched, massive disk galaxies. They may eventually become massive lenticular galaxies after they are cut off from their gas supply and their disks fade.« less
1973-01-01
Breaking the grip of the closed magnetic loops that constrain other gases around it, a spray of chromospheric material surges upward, free of the Sun. Views 1 through 5 were recorded about 5 minutes apart by Skylab and comprise a composite of separate images made in chromospheric (red), transition region (green), and coronal (blue) temperatures of an ultraviolet sequence that depicts a solar eruption. Eruption begins (view 2) as material in or near a small, compact loop develops enough energy to overcome the Sun's magnetic bonds.
2015-09-02
A small, but complex mass of plasma gyrated and spun about over the course of 40 hours above the surface of the Sun (Sept. 1-3, 2015). It was stretched and pulled back and forth by powerful magnetic forces but not ripped apart in this sequence. The temperature of the ionized iron particles observed in this extreme ultraviolet wavelength of light was about 2.8 million degrees C. (or 5 million degrees F.) http://photojournal.jpl.nasa.gov/catalog/PIA19878
Photographic and LMA observations of a blue starter over a New Mexico thunderstorm
NASA Astrophysics Data System (ADS)
Edens, H. E.; Krehbiel, P. R.; Rison, W.; Hunyady, S. J.
2010-12-01
On the evening of August 3, 2010 we photographed a blue starter over an electrically active storm complex about 120 km to the WNW of Langmuir Laboratory in central New Mexico. The event occurred close to a broad overshooting top at an altitude of 15 km above MSL. It was also observed visually and detected by the Lightning Mapping Array (LMA) deployed around the mountaintop observatory. The blue starter appears as a white-blue leader channel propagating away from the storm top not straight upward but at a large angle from vertical, slightly curving upward and transitioning to an increasingly diffuse blue glow. In addition to this leader, a more diffuse glow of blue light from one or two additional leaders is seen in the background. The curved channel of the main leader and the fact that it did not propagate along a straight path upward indicates that a relatively strong local electric field near the storm top existed that dictated leader propagation and direction rather than the large-scale storm electric field. The visible part of the starter is estimated to have developed to about 1 km above the storm top. From the LMA data we infer that the blue starter was a screening layer discharge that initiated between upper positive charge and a negatively charged screening layer. A negative leader appears to initiate at 15 km altitude and propagates downward for 2 to 3 km, after which scattered and ill-defined activity occurred in the cloud between 10 to 15 km altitude. This indicates that the visible part of the blue starter emanating out of the storm top, which was photographed but not detected by the LMA, was positive breakdown. The event lasted for 100 ms in the LMA data. The storm where the starter occurred in was producing predominantly intracloud (IC) flashes at a rate of about 20 per minute. The starter itself occurred independently of other discharges in the storm about 4 seconds after a normal polarity IC flash. About 5 minutes after the first blue starter, a second luminous event was recorded further away above the cloud top, which was similar but smaller in extent both optically and as detected by the LMA. It too was preceded by a regular IC flash 5 seconds earlier.
Thigpen, J. Ryan; Hatcher, Robert D.; Kah, Linda C.; Repetski, John E.
2016-01-01
An integrated synthesis of existing datasets (detailed geologic mapping, geochronologic, paleontologic, geophysical) with new paleontologic and geochemical investigations of rocks previously interpreted as part of the Neoproterozoic Walden Creek Group in southeastern Tennessee suggest a necessary reevaluation of the kinematics and structural architecture of the Blue Ridge Foothills. The western Blue Ridge of Tennessee, North Carolina, and Georgia is composed of numerous northwest-directed early and late Paleozoic thrust sheets, which record pronounced variation in stratigraphic/structural architecture and timing of metamorphism. The detailed spatial, temporal, and kinematic relationships of these rocks have remained controversial. Two fault blocks that are structurally isolated between the Great Smoky and Miller Cove-Greenbrier thrust sheets, here designated the Maggies Mill and Citico thrust sheets, contain Late Ordovician-Devonian conodonts and stable isotope chemostratigraphic signatures consistent with a mid-Paleozoic age. Geochemical and paleontological analyses of Walden Creek Group rocks northwest and southeast of these two thrust sheets, however, are more consistent with a Late Neoproterozoic (550–545 Ma) depositional age. Consequently, the structural juxtaposition of mid-Paleozoic rocks within a demonstrably Neoproterozoic-Cambrian succession between the Great Smoky and Miller Cove-Greenbrier thrust sheets suggests that a simple foreland-propagating thrust sequence model is not applicable in the Blue Ridge Foothills. We propose that these younger rocks were deposited landward of the Ocoee Supergroup, and were subsequently plucked from the Great Smoky fault footwall as a horse, and breached through the Great Smoky thrust sheet during Alleghanian emplacement of that structure.
Perception of Fechner Illusory Colors in Alzheimer Disease Patients.
Kaubrys, Gintaras; Bukina, Vera; Bingelytė, Ieva; Taluntis, Vladas
2016-11-30
BACKGROUND Alzheimer disease (AD) primarily affects cognition. A variety of visual disorders was established in AD. Fechner illusory colors are produced by a rotating disk with a black and white pattern. The purpose of our research was to explore the perception of illusory colors in AD. MATERIAL AND METHODS W recruited 40 AD patients (MMSE ≥14) and 40 normal controls (CG group) matched by age, education, gender in this prospective, cross-sectional, case-control study. An achromatic Benham's disk attached to a device to control the speed and direction of rotation was used to produce illusory colors. Primary, secondary, and tertiary RGB system colors were used for matching of illusory and physical colors. RESULTS Subjects in the AD group perceived less illusory colors in 5 arcs (p<0.05) of the 8 arcs assessed. The biggest difference was found between AD and CG groups for pure blue (χ²=26.87, p<0.001 clockwise, χ²=22.75, p<0.001 counter-clockwise). Groups did not differ in perception of pure yellow opponent colors (p>0.05). Mixed colors of the blue-yellow axis were perceived less often in AD, but more frequently than pure blue (#0000FF). The sequence of colors on Benham's disk followed a complex pattern, different from the order of physical spectral colors and opponent processes-based colors. CONCLUSIONS AD patients retained reduced perception of illusory colors. The perception of pure blue illusory color is almost absent in AD. The asymmetrical shift to the yellow opponent is observed in AD with red prevailing over green constituent. This may indicate cortical rather than retinal impairment.
NASA Astrophysics Data System (ADS)
He, Meiqin; Zhang, Jin; Wang, Hai; Kong, Yanrong; Xiao, Yiming; Xu, Wen
2018-06-01
The water-soluble fluorescent carbon quantum dots (CQDs) are synthesized by utilizing lemon juice as carbon resource via a simple hydrothermal reaction. The obtained CQDs are with an average size of 3.1 nm. They reveal uniform morphology and well-crystalline and can generate bright blue-green light emission under UV or blue light irradiation. We find that the fluorescence from these CQDs is mainly induced by the presence of oxygen-containing groups on the surface and edge of the CQDs. Moreover, we demonstrate that the as-prepared CQDs can be applied to imaging plant cells. This study is related to the fabrication, investigation, and application of newly developed carbon nanostructures.
Odour-based discrimination of similarity at the major histocompatibility complex in birds.
Leclaire, Sarah; Strandh, Maria; Mardon, Jérôme; Westerdahl, Helena; Bonadonna, Francesco
2017-01-11
Many animals are known to preferentially mate with partners that are dissimilar at the major histocompatibility complex (MHC) in order to maximize the antigen binding repertoire (or disease resistance) in their offspring. Although several mammals, fish or lizards use odour cues to assess MHC similarity with potential partners, the ability of birds to assess MHC similarity using olfactory cues has not yet been explored. Here we used a behavioural binary choice test and high-throughput-sequencing of MHC class IIB to determine whether blue petrels can discriminate MHC similarity based on odour cues alone. Blue petrels are seabirds with particularly good sense of smell, they have a reciprocal mate choice and are known to preferentially mate with MHC-dissimilar partners. Incubating males preferentially approached the odour of the more MHC-dissimilar female, whereas incubating females showed opposite preferences. Given their mating pattern, females were, however, expected to show preference for the odour of the more MHC-dissimilar male. Further studies are needed to determine whether, as in women and female mice, the preference varies with the reproductive cycle in blue petrel females. Our results provide the first evidence that birds can use odour cues only to assess MHC dissimilarity. © 2017 The Author(s).
Griewank, Klaus; Koelsche, Christian; van de Nes, Johannes A P; Schrimpf, Daniel; Gessi, Marco; Möller, Inga; Sucker, Antje; Scolyer, Richard A; Buckland, Michael E; Murali, Rajmohan; Pietsch, Torsten; von Deimling, Andreas; Schadendorf, Dirk
2018-06-11
In the central nervous system, distinguishing primary leptomeningeal melanocytic tumors from melanoma metastases and predicting their biological behavior solely using histopathologic criteria can be challenging. We aimed to assess the diagnostic and prognostic value of integrated molecular analysis. Targeted next-generation-sequencing, array-based genome-wide methylation analysis and BAP1 immunohistochemistry was performed on the largest cohort of central nervous system melanocytic tumors analyzed to date, incl. 47 primary tumors of the central nervous system, 16 uveal melanomas. 13 cutaneous melanoma metastasis and 2 blue nevus-like melanomas. Gene mutation, DNA-methylation and copy-number profiles were correlated with clinicopathological features. Combining mutation, copy-number and DNA-methylation profiles clearly distinguished cutaneous melanoma metastases from other melanocytic tumors. Primary leptomeningeal melanocytic tumors, uveal melanomas and blue nevus-like melanoma showed common DNA-methylation, copy-number alteration and gene mutation signatures. Notably, tumors demonstrating chromosome 3 monosomy and BAP1 alterations formed a homogeneous subset within this group. Integrated molecular profiling aids in distinguishing primary from metastatic melanocytic tumors of the central nervous system. Primary leptomeningeal melanocytic tumors, uveal melanoma and blue nevus-like melanoma share molecular similarity with chromosome 3 and BAP1 alterations markers of poor prognosis. Copyright ©2018, American Association for Cancer Research.
'Civil skepticism' and the social construction of knowledge: A case in dendroclimatology.
Ramírez-I-Ollé, Meritxell
2018-03-01
Early Science and Technology Studies (STS) scholars recognized that the social construction of knowledge depends on skepticism's parasitic relationship to background expectations and trust. Subsequent generations have paid less empirical attention to skepticism in science and its relationship with trust. I seek to rehabilitate skepticism in STS - particularly, Merton's view of skepticism as a scientific norm sustained by trust among status peers - with a study of what I call 'civil skepticism'. The empirical grounding is a case in contemporary dendroclimatology and the development of a method ('Blue Intensity') for generating knowledge about climate change from trees. I present a sequence of four instances of civil skepticism involved in making Blue Intensity more resistant to critique, and hence credible (in laboratory experiments, workshops, conferences, and peer-review of articles). These skeptical interactions depended upon maintaining communal notions of civility among an increasingly extended network of mutually trusted peers through a variety of means: by making Blue Intensity complementary to existing methods used to study a diverse natural world (tree-ring patterns) and by contributing to a shared professional goal (the study of global climate change). I conclude with a sociological theory about the role of civil skepticism in constituting knowledge-claims of greater generality and relevance.
NASA Astrophysics Data System (ADS)
Rogers, Stephen Christopher
It is often observed that the slimy matrixes of various bacterial-formed biofilms can limit their disinfection. This investigation demonstrated that disinfection effectiveness by either photodynamic therapy (PDT) or chlorhexidine irrigation is significantly improved by collapse of that matrix using the non-bactericidal reagent delmopinol as part of the treatment sequence. Cyclic shear-producing conditions were used to grow 4-day, whole salivary and growth media biofilms on glow-discharge-treated polystyrene (N=46) and mini-germanium internal reflection prisms to serve in a periodontal crypt model of disinfection by either methylene-blue-mediated PDT or by chlorhexidine irrigation. Assays for bacterial viability, with and without treatments, were performed by alamarBlueRTM fluorescent methods, statistically applied (ANOVA, Tukey's HSD). Multiple Attenuated Internal Reflection Infrared (MAIR-IR) assays confirmed selective removal of the predominantly polysaccharide matrix materials by the delmopinol treatment, but not by equivalent water or chlorhexidine methods. Confocal-IR microscopy showed that the delmopinol reagent, alone, caused about one-third of each wet biofilm to be removed, while bacterial re-growth was confirmed by alamarBlueRTM assay. Chlorhexidine and PDT suppression of bacterial activity without regrowth was significantly improved with the added delmopinol treatment, and is likely to provide similarly beneficial results in the effective disinfection of diverse biofilms in many settings.
The Star-forming Main Sequence of Dwarf Low Surface Brightness Galaxies
NASA Astrophysics Data System (ADS)
McGaugh, Stacy S.; Schombert, James M.; Lelli, Federico
2017-12-01
We explore the star-forming properties of late-type, low surface brightness (LSB) galaxies. The star-forming main sequence ({SFR}-{M}* ) of LSB dwarfs has a steep slope, indistinguishable from unity (1.04 ± 0.06). They form a distinct sequence from more massive spirals, which exhibit a shallower slope. The break occurs around {M}* ≈ {10}10 {M}⊙ , and can also be seen in the gas mass—stellar mass plane. The global Kennicutt-Schmidt law ({SFR}-{M}g) has a slope of 1.47 ± 0.11 without the break seen in the main sequence. There is an ample supply of gas in LSB galaxies, which have gas depletion times well in excess of a Hubble time, and often tens of Hubble times. Only ˜ 3 % of this cold gas needs be in the form of molecular gas to sustain the observed star formation. In analogy with the faint, long-lived stars of the lower stellar main sequence, it may be appropriate to consider the main sequence of star-forming galaxies to be defined by thriving dwarfs (with {M}* < {10}10 {M}⊙ ), while massive spirals (with {M}* > {10}10 {M}⊙ ) are weary giants that constitute more of a turn-off population.
Geology along the Blue Ridge Parkway in Virginia
Carter, Mark W.; Southworth, C. Scott; Tollo, Richard P.; Merschat, Arthur J.; Wagner, Sara; Lazor, Ava; Aleinikoff, John N.
2017-01-01
Detailed geologic mapping and new SHRIMP (sensitive high-resolution ion microprobe) U-Pb zircon, Ar/Ar, Lu-Hf, 14C, luminescence (optically stimulated), thermochronology (fission-track), and palynology reveal the complex Mesoproterozoic to Quaternary geology along the ~350 km length of the Blue Ridge Parkway in Virginia. Traversing the boundary of the central and southern Appalachians, rocks along the parkway showcase the transition from the para-autochthonous Blue Ridge anticlinorium of northern and central Virginia to the allochthonous eastern Blue Ridge in southern Virginia. From mile post (MP) 0 near Waynesboro, Virginia, to ~MP 124 at Roanoke, the parkway crosses the unconformable to faulted boundary between Mesoproterozoic basement in the core of the Blue Ridge anticlinorium and Neoproterozoic to Cambrian metasedimentary and metavolcanic cover rocks on the western limb of the structure. Mesoproterozoic basement rocks comprise two groups based on SHRIMP U-Pb zircon geochronology: Group I rocks (1.2-1.14 Ga) are strongly foliated orthogneisses, and Group II rocks (1.08-1.00 Ga) are granitoids that mostly lack obvious Mesoproterozoic deformational features.Neoproterozoic to Cambrian cover rocks on the west limb of the anticlinorium include the Swift Run and Catoctin Formations, and constituent formations of the Chilhowee Group. These rocks unconformably overlie basement, or abut basement along steep reverse faults. Rocks of the Chilhowee Group are juxtaposed against Cambrian rocks of the Valley and Ridge province along southeast- and northwest-dipping, high-angle reverse faults. South of the James River (MP 64), Chilhowee Group and basement rocks occupy the hanging wall of the nearly flat-lying Blue Ridge thrust fault and associated splays.South of the Red Valley high-strain zone (MP 144.5), the parkway crosses into the wholly allochthonous eastern Blue Ridge, comprising metasedimentary and meta-igneous rocks assigned to the Wills Ridge, Ashe, and Alligator Back Formations. These rocks are bound by numerous faults, including the Rock Castle Creek fault that separates Ashe Formation rocks from Alligator Back Formation rocks in the core of the Ararat River synclinorium. The lack of unequivocal paleontologic or geochronologic ages for any of these rock sequences, combined with fundamental and conflicting differences in tectonogenetic models, compound the problem of regional correlation with Blue Ridge cover rocks to the north.The geologic transition from the central to southern Appalachians is also marked by a profound change in landscape and surficial deposits. In central Virginia, the Blue Ridge consists of narrow ridges that are held up by resistant but contrasting basement and cover lithologies. These ridges have shed eroded material from their crests to the base of the mountain fronts in the form of talus slopes, debris flows, and alluvial-colluvial fans for perhaps 10 m.y. South of Roanoke, however, ridges transition into a broad hilly plateau, flanked on the east by the Blue Ridge escarpment and the eastern Continental Divide. Here, deposits of rounded pebbles, cobbles, and boulders preserve remnants of ancestral west-flowing drainage systems.Both bedrock and surficial geologic processes provide an array of economic deposits along the length of the Blue Ridge Parkway corridor in Virginia, including base and precious metals and industrial minerals. However, common stone was the most important commodity for creating the Blue Ridge Parkway, which yielded building stone for overlooks and tunnels, or crushed stone for road base and pavement.